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WORKS  OF  PROF.  A.  F.  HOLLEHAN 

FUBtlSHED  BY 

JOHN  WILEY  &  SONS. 

A  Text-book  el  iBOTfank  CbMUlstO'. 

Ety  Dr.  A,  F.  HoLLSHAH,  Profe«ioT  Ordiuariiu  in  (he 
Unlvenlty  of  Croniagcn,  Nelherlandt.  Rendered  into 
English  by  HKKUnN  C.  CaorsK,  Ph.D.,  InitnKtor  in  Syr- 
acuse University,  with  the  ca-operadon  o(  the  author.  8vo, 
viii  +  4jS  pp.,  84  figures.    Cloth,  fi.jo. 

A  Tast-b«ok  of  Organic  Cbcmlrtry. 

Rendered  into  English  from  the  Second  Dutch  Edition  by 
A.  Jahiisoh  Walker,  Ph.D.  (Keldelbeix),  B.A,  Head 
of  Department  of  Chemistry,  Municipal  Technical  College, 
Derby,  Eng.,  assisted  by  Owen  E.  Murr,  Ph.D.  (Kei- 
'  delbeix).  Demonstrator  ofChemtslrr,  MunicCpsl  Technical 
College,  Derby,  Eng  ,  with  the  co-opeiation  of  the  author. 
Bvo,    avii  'f.  355  pages.  73  figures.     Cloth,  $9.50. 

A  companioD  volume  lo  the  preceding,  and  lonning  with 
It  a  comprehensive  treatise  on  pure  Chemistry. 


A  TEXT-BOOK 


ov 


ORGANIC    CHEMISTRY. 


'     BT 

Dr.  A.  F.  HOLLEMAN, 

Frofeuor  Ordinariui  in  the  UaiverMg  of  Oroningen,  A'etherUmda. 


TRAKSLATSO  FROlf  TBB  BSCOHD  DUTCH   BDrTtOS  BT 

A.  JAMIESON  WALKER,  Ph.D.  (Heidelberg),  B.A., 
Bead  of  the  DepartmetU  ofChtmtUtry,  Municipal  Technical  OiBege,  Derby,  England. 

ABBISTED    BT 

OWEN  E.  MOTT,  Ph.D.  (Heidelberg), 
Dtmanttrator  of  GKemuitry,  ManMpal  Technical  College,  Derby,  England. 

WITH  THE  CO-OPEBATION  OF  THE  AUTHOR. 


FTBST  EDITION. 
FIEST    THOUSAND. 


NEW  YORK : 

JOHN  WILEY   ft   SONS. 

London:  CHAPMAN  ft  HALL,   LrurrED, 

1903. 


Oopyrtibt,  1MB, 

BI 

A.  JABUESON  WALKGS. 
(£Mt«r«d  at  SloHontn'  BaU.) 


■osnr  DKDMiioin),  ranmtB,  xkw  tork. 


AUTHOR'S  PREFACE. 


Most  of  the  short  text-books  of  Organic  Chemistry  contain  a 
great  number  of  iaolat«d  facts;  the  number  of  coropounda  de- 
scribeU  in  them  is  so  considerable  as  to  confuse  the  begUmer. 
Moreover,  the  theoretical  grounds  on  which  this  division  of  the 
scicace  is  based  are  often  k«pt  in  the  baokgroui^;  for  example,  the 
ppoofn  given  of  the  constitutional  formula  frJ^ently  leavp  much 
to  be  desired.  However  useful  these  books  may  be  for  reference, 
they  are  often  ill-suited  for  text-books,  as  luany  atudents  have 
Ii'anicd  from  their  owti  experience. 

Ill  this  book  I  have  endeavoured  to  keep  the  number  of  unron- 
nectcd  (acts  within  as  narrow  limits  as  possible,  aad  to  give  promi- 
nence to  the  theory  undc-riying  the  subject.  For  this  reason,  * 
pmiif  of  the  sLructiuT!  uf  most  of  the  compounds  iK  given.  This 
wa»  not  possible  for  tlie  higtiex  substitution-prochicts  of  the  aromatic 
si-rUis,  so  tliat  the  methods  of  orientation  employwl  in  it  are  de- 
scribed in  a  simrial  chapter. 

Physico-chemical  theories,  suoh  as  the  Uws  of  equilibrium, 
ionization,  and  others,  are  becoming  more  and  more  prominent  in 
organic  chemistry.  1  have  attemptfld  in  many  instances  to  show 
how  useful  \hey  are  in  this  branch  of  the  ncience.  Such  importaat 
technical  processes  as  the  manufacture  of  alcohol,  cane-sugar,  etc., 
are  also  incluiled.  The  book  is  essentially  a  text-book,  and  makes 
no  claim  to  be  a  "Bcilatcin"  in  a  very  compressed  fonn. 

]  am  deeply  indebted  to  Dr.  A.  J.^miison  Walker  for  the  excel- 
lent way  iu  which  he  has  carrierf  out  the  difficult  lank  of  translating 
tliis  book  from  the  original  .second  Dutch  edition  into  Knglish. 
Lastly,  it  may  be  mentioned  that  it  han  altui  been  translated  into 
German,  the  scccmd  edition  having  just  appeared,  and  that  aa 
Italian  edition  is  in  preparation. 

A.  F.  Hdlleiuak, 

QaoNiMOKil,  NxTaRHLAKiM,  Noveoiber,  1902. 

IU 


TRANSLATOR'S  PREFACE. 


The  cordial  reception  met  with  by  Professor  Hollbman's 
"Leerboek  der  Organische  Chemie"  in  HoUand,  as  well  as  by 
Dr.  Hof's  translation  in  Germany,  makes  it  cfffiirable  that  English- 
speaking  students  of  chemistiy  should  share  in  the  advantages 
derived  from  its  publication  by  their  fellow-students  on  the  Con- 
tinent of  Europe. 

This  tt-anslation  is  from  the  second  Dutch  edition,  published 
last  year,  and  has  been  revised  and  added  to  by  Professor  Holle- 
MAN  and  myself  bo  as  to  make  it  as  up-to-date  as  possible.  An 
Italian  translation  of  this  English  edition  is  now  in  preparation. 
The  "  Inorganic  Chemistry  "  referred  to  in  the  text  is  Dr.  Cooper's 
translation  of  Professor  Holleman's  "Leerboek  der  Anorganische 
Chemie,"  pubUshed  last  April  by  Messrs.  John  Wiley  &  Sons. 

I  have  to  express  my  thanks  to  Professor  Holleman  for  the 
great  care  bestowed  by  him  on  the  work  of  revision;  to  Dr.  Owen 
E.  MoTT.  for  his  valuable  assistance ;  to  Professor  Senier  of  Queen's 
College,  Galway,  for  reading  the  proof  and  making  many  important 
suggestions;  to  Dr.  John  E.  Mackenzie  of  the  Birkbeck  Institution, 
London,  for  reading  part  of  the  proof;  to  Dr.  Hermon  C.  Cooi-eb 
of  Syracuse  University  for  the  note  regarding  the  law  regulating 
the  sale  of  alcohol  in  the  United  States;  and  to  Messrs.  John 
Wilet  &  Sons  for  the  excellent  way  in  which  they  have  prepared 
the  book  for  publication. 

'  A.  Jamisson  Walker, 

Debbt,  Enqland,  December,  1902. 

r 


CONTENTS. 

Light  figuiM  refer  to  pages;  old-€tyle  Sgures  to  peragT^>hs. 

INTRODUCTION  (i-aS) 1 

IJsvKtopMiMT  OF  Organic  Chemistrt  (i-a) 1 

QrAUTATIVE  ANALTSIB  (3-5) 3 

QcANTiTATivH  Analtsis  (6-g) 5 

I>£TERMINATION  OT  MOLECULAR  WEIGHT  (IO-I5) , 12 

Vapour  density  method,  13.  Lowering  of  the  freeting-point  and 
Raising  of  the  boiling-point  methods,  16. 

The  Element  Cabbok  (i6) 21 

Valency  (17) 23 

Laboratort  Mcthods  (18-27) 24 

Heating  substances  together,  24.  Distillation,  25  Steam  distil- 
lation, 28.  Separation  of  two  immiscible  liquids,  30.  Separa- 
tion of  solids  and  liquids,  31.  Separation  of  solids  from  one  an- 
other, 32.  Determination  of  melting-points,  32.  Determination 
of  boiling-points,  33.  Detennination  of  specific  gravity,  33.  Ro- 
tation of  the  plane  of  polarization,  33. 
Classification  of  Oeoantc  Chsuistry  (aS) 35 

FIRST   PART. 
THE  FATTY  COMPOUNDS  (29-358) 36 

Sattratkd  Hydrocarbons  (39-43) 36 

Methane,  36.  Homologues  of  methane,  38  Nomenclature,  39. 
Occurrence  in  nature,  39.  Homologous  neries.  41.  Isomerism 
and  structure,  42.  Carbon  chains,  46.  Law  of  the  even  num- 
bers of  atoms,  47.  Number  of  possible  isomers,  47.  Physical 
properties  of  isomeric  compounds,  48. 

Alcohols,  C,H,„  +  ,0  (43-55) 49 

Methods  of  formation  and  constitution,  49.  Nomenclature  and  iso- 
merism, 51.  General  properties,  52.  Methyl  alcohol,  53.  Ethyl 
alcohol,  53.  Propyl  alcohols,  S7.  Butyl  alcohob,  59.  Amyl 
alcohola,  60.  Van  't  Hoff's  theory  of  stereotsomerism,  62. 
Higher  alcohols,  66.    Alcoholates  or  metallic  alkoxides,  66. 

Til 


TiU 


CONTENTS, 


ALKTt.  Halidm,  Bams,  juni  Brana  Csfl-ti4) 67 

Alkyl  halidM,  68.  Eaton  of  othir  mineral  aeida,  71.  SaponiAca^ 
lion,  72.  Rtlivrs,  72.  Diotliyl  vlhcr,  73.  Uoinolr^ucs  of  di- 
elhyl  ellier.  75. 

AutVL-aAUicLGM  L[MKr.»  ■m  Sri-Mim  (65-*8) 77 

Mrrcupttin5,  78.    Thi«»-tlifni,  70.    t^tilphcuii^  itridB,  78. 

ALKVt^IIADIPLEB  LiXKBD  TO  NlTKOGES  (*9-77) M 

Amirtct  ($9-74) SI 

Nomenclnturo  and  uomprism,  83.     Methods  of  formatioii,  ti2. 
I'ropiTlli's,  SI.     I»dlvidiial  ine!reib«f!i,  85. 
tfitn-wmjiautida  (75-7T)... 8S 

Al.KYI^KAI>ICLXf  I.I.VKKU  TO  OTRKIl  KlUIKNT*  (TS-Si) 92 

.Ukjjt-mdifUi  UnkeH  to  flrmenlt  of  Iht  fiilrojftn  group  (7S-B0) 02 

Pboaphince,  92.     Arsinrs,  03.    Slibitirai,  IM.     Bismutliiaca,  M. 

Alkijl-raitidis  linktit  to  thr  rlttnent*  of  tlu  tarbon  group  lit) M 

Alkyl-radifU»  Urtkcd  to  ttutaU  (81) Qfi 

NmULSS  ANU  InOMTHIU^  (Sj-Ss) ..j  .  .  .  . .       07 

iBonitriloa  or  corbvlamines.  08      Nilriles,  09. 

AciM,  CHjbO,  (86-ii4) 101 

Formii;  arid,  104     Acetic  arid,  10(1     Butyric  acids,  10&.    Higher 

(nliy  Btids,  109.     Sr.inp*,  110      KWlrttljIic  rliwwuitioii,  HI. 

DUHIVATIVKA  (IK  THB  FaTTY   AcIIM  OBTA]>fEO  BY  MoDIFTINO  THE  CaK- 

Boxrixmoup  (os-ios) 1 U 

Aci<f  ehl^tde*  (95) 1 H 

vicuf  atihsdridet  (g6) IIS 

A'jH*r«  (97-IC3) 115 

Foniialiou  of  wtcra,  117-     EslerifiCAticn  of  prLin»ry,  aecoud- 
ary,  itnd  icrtinry  otcoholit,  121. 

Thta^eutM.  K  -Oft  SH  "<io3) 121 

Add  amidn  ( 104^ 121 

AmuiiKhlnridnt.    fmino-^thera.  Amuitnet,  Amidvxima,  Acid  hydros 

«d«  and  Aftd  ntiiien  (105J 133 

ALDBUTDEtt  AN1>  KK1t)Nt:n  (  lod-lSl) 125 

Nomenclature,  127      Methodi  of  formation,  127,     Properties,  129 
AUMydf*  (113-118). 133 

PropiTti(«.  133.    Teals,  13fi.     Foniialdeliyde,  137     Acctaldfr 
hydf.  1^ 
Kelt>nta  (ii^i  ii«] 199 

Acetone,  140. 
Th\rMiddi\fdt»  nnd  Thir)kelcmtM  (Ul) 140 

ITNSATT'RATEU   IlYIMlOCAtlllO.VB   (133- IJ4) 141 

AikiHrnrx  or  Oirfinrn  (i 32-1 19) 141 

Methods  ot  fnntijition,   141.         Pnip'rl ii's,  142.     Klhylrn^i,  144. 
Auiyleutrif,  144      The  nalurv  of  llid  double  curbon  buad,  145. 
Baeveh's  tension  thetirv,  l&O. 
Peiymethylent  compoundt,  CnH,.  (130) ISO 


CONTENTS.  ix 

Eydrocarhona  C.H,,  _ ,  f  131-134) 150 

A.  HydroearboTu  with  triple  bonds  (i3>-i33) 161 

Nomenclature,  151.     Methods  of  fomutiOD,  151.    Pro> 
perties,  152.    Acetylene,  154. 

B.  Hydrocarbons  vtith  two  dovide  bonds  (134) 165 

SoBanTDTiON-PHOPUCTB  oy  THE  Unsatdrated  Htdrocabbons  (135- 

138)  156 

Unsaturated  halogen  compounds  (135) 156 

Vnsaluraled  alcohols  (136-138)   158 

Vinyl  alcohol,  159.     Allyl  alcohol,  159.    Propargyl  alcohol,  160. 

MoNOBABic  Unsaturated  Acii>s  (139-146) 161 

Adda  of  Ihe  oleic  series,  CdH,.  _  ,0,  (139-144) 161 

Methods  or  formation,  161.  Nomenclature,  161.  General 
properties,  162.  Acrylic  acid,  162,  Acids  with  the  fonnula 
C,H.O,,  193.    Oleic  acid,  163.    Elaldic  acid,  165. 

Adds  of  the  propiolie  series,  C.H,b_^Oj  (145-146) 165 

Acids  with  two  double  bonds  Ci.H,b_40„  167. 

Unbatcrated  Aldehtdes  and  Ketones  (147-149) 168 

Unsaturated  aldehydes  (147-148) 168 

Acrolein,  168.    Crotooaldehyde,  169.    Propargylaldehyde,  169. 

Unsaturated  ketones  (149) 169 

Mesityl  oxide,  169.     Phorone,  170. 
CoupouNDs  Containing   more  than  one  SuBSTmrriNo-aRoup  (150- 

i6a)  171 

Halogen  derivatives  of  methane  (150-153) 171 

Chlorofonn,  171.  Chloropicrin,  172.  Methylene  chloride,  172. 
Tetrachloromethane,  173.  Bromoform,  173.  Iodoform,  173. 
Methylene  iodide,  174. 

Halogen  derivatives  of  the  homologues  of  m^hane  (153-194) 174 

Methods  of  preparation,  174.  Nomeoclature,  and  individual 
members,  175. 

Poiyhydric  alcohola  (155-161) 176 

Glycols  or  dibydric  alcohols,   177.    Trihydric  alcohols,   179. 
Tetrahydric  and  higher  poiyhydric  alcohols,  183. 
Derivatives  containing  halogen  atoms,  hydroxyl-groups,  nilro-grotips, 

or  amido-groupt  (i6a) 184 

POLTBABic  Acids  (163-177) 188 

Saturated  dibasic  acids,  C,H,,_,0,  (163-169) 188 

Physical  and  chemical  properties,  1S8.  Oxalic  acid,  190.  Ma- 
lonic  acid,  192.  Succinic  acid,  194.  Glutaric  acid,  196. 
Electro-synthesis  of  dibasic  and  other  acids,  196.  Forma- 
tion of  anhydrides,  198.  Saponification  of  the  esters  of  the 
dibasic  acids,  200. 

Unsaturated  dibasic  acids  (170-173) 201 

Fumaric  and  maleic  acids,  201.  Acetylenedicarboxylic  acid, 
206.    Affinity  constants  of  the  unsaturated  acids,  207.    Di- 


CONTENTS. 


ace(}-liii4HlieiirI)oxylir  A<*id,  207.    Tl>1^uu^crtyle^ediparbpxylic 
ftcid,  2tl7. 

Po)y&a»iC  aeida  (174-177)... 207 

TrilMAic  widn,  ZOS.  Tetrabnaie  Midti,  309.  HighiT  polybaaic 
aci<l«,  210. 

ScBSTiTirTKW  AciDB  (178-301) 211 

/  aogen-mbgtilHttd  aeidn  (178-181} , 211 

Mcthotls  or  fopRintion,  211.  Properlim,  213.  CUoioaoatie 
ncidx,  21:1.  /J-ImlupropioDic  lu-id.  213.  Adds  DonuUning 
moN  than  onp  hn.l«(p-n  ntmii  111  t.ht;  moliM^ulu,  214. 

lirnielbagic  hijilroj:ii-<tcuh  (iSi-iSSi    216 

HelbnU  cf  fornintion,  210.  rmprrlies,  217.  GlycotUc  aptd, 
219.     l.aclii:  iindu,  SID.     LocIodm,  223. 

Dibaiue  hydmxv^rtilt  {189-107) 225 

THrlmnic  ni'iil.  22.S,  Mnlie  arid,  226.  SivmrisompriBin  of  the 
turttu-iv  iH'ids,  22ii.  L'extro-iarianr  ftcid,  33L.  Ltcvo-tu^ 
laric  iM-id.  233,  Riin?tiiir  •cid.  233.  Mraotartaric  »cid. 
'2'M.  RAMiniic  aubalanree  iind  thf>ir  sFpaisiion  into  opitcidly 
active  coiwiilHcnt.*,  iS**. 

Polylninc  Jiifiirojij-acitU  (ipS) 241 

fitric  iwid,  241, 

Amiit*f-acida  (igQ-aoe). 211 

Mclhodn  of  formalion,  242.  rroptniw,  343.  l-iatCTs,  244. 
Indivkliud  iiicnil<<-ni,  244.     DiftJKMiwtir  L><tM-,  347. 

DULDEtlTItEH   AMI   DlKETOMO*;   IIaLOQEN   UKRIVATn'Efl  or  THS   Au>B> 

HVUKK  AND  Kktonrh  (20a-xos) 248 

Diaidtki^dtx  (MJ) , * 243 

iMtoone*  (»03> 249 

DkMUjrl,  340.    AMiylacetonc,  330.     AcetonylftcetooG,  251. 

Ualoftn-tvf'tlithled  aldtits*tn  (m4) 231. 

Oilond,  2.')I. 

UalafftH-MjbittilMltfl  ketot\e*  ( J05) 2S3 

Ai-DEiiTBK  AKO  Kktoms  .Xummuui  uh  .SvnAfiA  (sofr-ajl) 254 

XvmmriatvTt  and  j/enerai  propertif  ol  the  monocM  and  Iktir  deriva- 

lie«4  (M7-)o8) 3M 

Cotulihilum  oj  (A«  iimimmm  (309),, ..< , 2S7 

Unkodt  of  Jormation  of  Ike  moaote*  (ato) 2^ 

Mom^re*  <aii-3J4) " 262 

Peotowa.  202.  Itoxoir*.  264.  Hrptogt*,  266.  Ortosni,  209. 
MontMm,  2S9.     SiereocliemMn-  of  tbo  moBOMS,  3ft9. 

.Kmm  (3is-»3l ■ 272 

Ualloac.  273.  L*tioie  or  inilk.4i)[iir.  273.  SttrroM  or  cane- 
sugar,  374.  Manufacture  oi  emn^-tngnr,  376.  Quantitn- 
tin  Gstiinatjoa  of  canv-sugar,  277.  ^'ctoci^y  of  inrmMB 
of  auerow,  278.  Fermeniatioa  and  tiie  aelion  of  cnsyuia, 
379. 


CONTENTS. 


XI 


Potyote*  (114-231) 383 

RaffiiWM,  383.  Higher  polyo^M,  283.  Stuvh,  384.  Mitnti- 
fociure  ol  rtiuch.  2S6.  Clycogeii,  2S6.  Ce'.liiloac.  2A7. 
Twhnical  8ppli«aIioiui  oT  n-1ltiio>>v,  2S7.  Nitraivs  or  ccUu- 
low,  288. 

AuiNo-DKRivATiinn  or  tiib  ALDEHTDEa  Asv  Ketoves  (jji) 2S9 

Ai.i>EaTi>ic  AND  Kktosic  .AriDH  (133-340) 290 

Choxylic  atid,  2)K).  I'yraruceiiiic  acid,  290.  Ari-loiuMTtir  acid  am] 
Mvtoacrtic  n>4cr,  291  L^vulinic  tkrid.  293.  Mpsooulle  Mid, 
293.  OxAlMwti«  acid  and  oxftlact-tic  cuttr,  296.  AMtoii«dicu^ 
boxylic  acid,  29*. 

Tautawritn  (340) M7 

Plfmnt  dcnmdVe*  {14*1 3U3 

fL'^cttdcnik  nrid,  302.  Xanthorhrlidonic  nctd.  302.  DImethyJ- 
pyrone,  31H.  TftrHvalciioy  of  ox>*(Cfn|  3tM,  O-tonium  anil*, 
305. 

Ctakooen  Dkhivatives  (141-147) 308 

Cynnoiewi.  308.  Hyitrm^tuiir  wid.  3IW  IVnntdpii,  3in.  C>"*nif 
iw-kI,  311.  Tlii<K'yu)ii<T  ncid,  313.  MiintAr\l-uilt>,  31-t,  Cyan- 
auiide,  315.  Fulniiiuc  acid,  3Ii.  Cj'anuric  arid,  31fi.  Isoci-ft- 
Riiric  ncid,  31G. 

I>ERiv.\Ti\'Ea  or  Carbonic  .Acid  (148-156) 317 

C«rbo&yl  chloride,  317.  Cnrlion  disnlphidr,  318.  Xanthic  acid, 
318.  Carbon  ox>'sulphid«,  SIV.  Vn-n,  31(>.  Biunt,  322.  Scmi- 
cariiaiid*,  323.  CarbBiiiic  atid.  323.  Urciliniics.  324.  'Hiio- 
uwfl,  325.     Ciuaniilinr,  32B.     Aniinm*-,  327. 

Umc  Aa»  fiiirmr  (257- 158) 328 

L'ric  arid.  32S.  Parabftnic  acid.  328.  .\lloxan,  328.  AllaxaniinP. 
32n.  AUanloTnr,  32i).  Malonvlnn-u,  XHI.  Violurio  acid,  330. 
Aminolmrlnliirio  nciil,  3.11).  Psiiidii-iirir  icid,  331.  Hypuxtui- 
llunc-,  331.  XaniKine,  331.  Gtmnini}.  331,  l'h<?ol)n)tnine,  a32. 
CaiTctDv.  332.  Punnc,  333.  £ulL  Viexaam'i  ti>-iithtiiis  of  tlico- 
bromiiM)  and  caffeiine,  333. 

EUetro-rtdMtiMt  of  purine  derivalivM  (158) 334 

Droxy-derivativfH,  334.  Purviie,  335.  Tato.'b  elcctru-rcduc- 
tion  metbod,  33A. 


SECOXI)   PART. 


THE   AROMATIC   (X)MrO[rNl>S  AND  SUBSTTANCES  REtATEn 

TO  THEM  (159-41B) 338 

iNTRODVCTtON  (l9«) 338 

PoL.TMETNTi.KNK  l>i:Rn:ATiv»i  (i6o-a6a) 340 

TrtmtiHijIene  lierivtitiva  (160).... 340 

Trtramfthi/tcne  dericotitf*  (lAi) •• 3-10 

J'€nlamelhyUne  dtrivatives  ()6)) 340 


zli 


CONTENTS. 


Ooaatnrunojf  or  BcsxEarE  (163-364) 343 

Ctathc  [onnuU,  310.    NoateocUture  and  iaocarriBni  of  the  bcD- 
tcDC  (lcTi%-atires.  347. 

nilM'SnTO    CBARAC-TtBtETIC     OT     TIIE     AROMATIC    COKfOTTyos;    BtV- 

Timcs  FROM  i.vm  (.'oMTOt-KPfl  (a6s~i66) 349 

rn>ppni<--t  nf  \hr  .vnruntir  c(itn|MJiJiid<),  549.     8>-nlhi.'ees  of  aroniatic 
(lompounds  from  tlicup  of  the  aliphatic  aeriM,  350. 
KniEXK  kso  TUB  Akomatk)  Hvi>iKK\utuoNa  WITH  Satcbated  StDE- 

CKAixK  t>67-Z7a) 351 

GM-mAoufwiim  utd  iu  b>--pro(lucU;  tar,  351.    Hethodn  of  (<»• 
UBtioD,   &S2     Indi^HduAl   mcmbcn,   3&1      Hvdragca  odditioQ- 
prodtirU  of  the  aronuiic  hydrocarboiM,  :i55. 
Ml)JCO«PMTiTrnox-nioi>t:CT«  of  th«  AnouA-nc  Mtsrocarboxs  (»7I- 

a^i)    357 

Mvmmijiumieaeid»i37i'i 357 

JtfvmAiilegwKtvDipranift  (171-37$) 35t$ 

Melboda  of  foimation,  330.     IndividuAt  tU'embcn,  330. 

iitm<A^nef^>tnoltandliTomaii£^da>hoU(l^^l•fi) 360 

A.  Phcnola  (374-J76) 361 

Mtitliod-i  of  formation,  3C1.     Ptoperties,  361.    IndividuAl 
mnnlwre,  382. 

&.  Aronu>tic(tlcoii<>lB{a77) 363 

BenE)-!  xlruhul,  3U3. 

Sulpkvr  (Urxv<Uiv4M  (377) 363 

TiiiupbiCDol,  363 
EttwnliyB) 364 

J/«»«mt/n)-»fon*tKl/i*rM   (179-381) 364 

Mnliod  of  fonnatioii,  364.  PrnpRrtim,  365.  IntUvidu«l  mcm- 
ben.  .'Wfl.     Fhi?ny)nitroniinlkane.  3C6.    Pseudo-Bcids.  307. 

iJinuMimiruy-eompouitda  <)8i'*S8> 368 

Melhuds  of  ftiniiation  and  propertlM,  36S.  .Aolline,  370. 
Huiniilugtin*  of  iiniliiK!,  371).  Si-t'uiiilArv  auiioM,  371.  Tor- 
liaxy  luiiuusi,  373  Qii&lofiiary  Laks,  374,  Benxylomiue, 
372.  Curbonir  itcid  drrirntivM  of  anjliiic,  375.  ikdphur 
deiivativcN  of  Aniline,  376. 
ItUtrmediate  prvivcU  in  Oit  rcdiKtion  of  arvmatie  nttn-wmpminda 

(iSo-ioi) 376 

Axavj'bonxnip,  376.  Axobrnxpiiic,  377.  HydniobvnxvtM),  377. 
Klectro-frduci  ion  of  nitra-coiapouiidn,  378. 

Phtnjrl-ampOHniU  cotOainijig  alh£r  flmmtl*  i2Q3-J9S)  . . 381 

Pbo^haruii  and  Aniom«  d«rlvaUvM,  3St.  CompAn»oa  of  the 
aroiDAtic  dcrivAtivca  of  nitrogen,  phosphorus,  and  uscnlc, 
3X1.     .Aftiiiutlicf  mrlAllic  eoinpoundx,  '.ixi. 

BcNzotc  Acid  and  it»  !)Ejtn'ATm»  akd  Ho«oi.ogi'c*  (196-198) 383 

Sr-nzoir  ni-id,  383.     TVrivalivca  of  Leusoic  acid,  3&^.     UomoIogU'Ca 
of  benzoic  arid,  387. 


i 


i 


i 


CO»T£NTS. 


XIII 


rAOc 
hTto  ALommBs  AND  KerOKKi^  (399-301) 388 

Buuutklchycle,  and  its  hoinnluguM.  3Sli.  Beaxopbeaooe.  390. 
HAeakkcm'h  theor\'  of  tho  «ynihi-j'bt  of  tltv  unnuiic  luMones,  3V1. 
ytwiwisouwrinm  of  the  aroniatk  o.xiniea,  391. 

i(xtiMrorNi)»  AND  Hydraiim:»  (303-^5) 895 

iKtuo-nmt/iOMwiH  (301-304I 393 

Uolhmls  vl  ftiriiiiil.imi,  nnd  coiidtitulion.  Sy.'S.  Rroctionn  of 
ttu'  liijuoniuiii  compound.').  3yi>,  Haxtmcm"*  llieory  of  the 
traDBfoniiBlioiui  of  the  ditizoniiim  rompoundM,  TO8.  Rvtuy 
twa«  11S  the  duuDiiLiun  coiu|M}iinils  in  irtucb  the  mtn^co 
Btoma  are  not  «Umiiiiit«d,  401. 

//yrff«n"ft«t  [305) 408 

Ptienvlhyilnixlne,  ^02.     Mcthylpfamylhrdnuinc,  404. 

CoUPOTINtMtCoNTAlMKO  AN  L'.VKATUnATKD  SlDE-CIUlK  (3O6~3O0> 405 

HydrocurbouB,  4U5.     .XJcobol*  utd  uidchv-dw,  405.     .Vcids..  -106. 

Poi.V-«Ut»TITirrKI>    llBaiVATIVDB    COHtAUnHO    SllitUAH    t^UUBTITDKNTB 

(3to-33i> 407 

JWyjru//iAi7ntC««iii«(3lt).., 408 

PolyhalofftnilfTiiiUiveii(,3ti) 4()S 

Pvli/kyilrte  fihenol)'  (313-315)    409 

Dibydric  phcaula.  406.  Trihydrii:  phenob,  410.  Higlwr  pli«u> 
oU.  411. 

QuinoMD  <3i6-3i7)    412 

J*oli/nilro-derititlife9{itS) 414 

Foti/amMo-^omfiiituidtandthinrtbTitttliv*tlst^324) 415 

Phmylraediftininea,  415.    Aao-dyvd,  410. 

PoI>/iM*it  aeidii  (3^5-331) 419 

Dibasic  acids  (Jjs-Jio) ^W 

PhthAlio   Ac-id,    4111.     l>rrivnii\'M  ^f   phllialie  acid,  420, 
laophtliulit^  ami  U'n'plitlialit  atids,  423 

Htglirr  |Milyliuneiu-iilii(33i; 423 

!tivATT<-£«  CoKTAWtNg    IVo  OH  MoBB  Du«aiii4it  SDBanrcsNm 

(S3«-M0 .;;;... 424 

Stitplio-Jfrindirtt  (33^-335)    424 

Uokig^rn  siilphonic  ncids,  424.  Phenol«uIphoni(?  ncidt,  424. 
Sutplianilic  itfid,  424.    SulphobenxoCc  actd*,  425^ 

/fologmdM-intfiivj  (336-337) 425 

HiduReii  |ilicii»l».  ■i2i.     Halogen  b«iusoiic  acids,  420. 

Ilstttmri/i-drr(nihi-r*  (3S»-348) 428 

NitrOMtphenol,  42tt.  N'itrophonok,  427.  AminnphcnoiR,  4?d. 
MoQOhydfoxy-acidjt,  43U.  I'ruof  of  the  <t|unlity  of  the  fix 
bydragcQ  atotrw  of  bt^tuMie.  4:^2.  Dihydroxy-scids,  434. 
1^ihydrox)'-««:ide,  434.  Acid*  containing  hydrosyl  or  Mir- 
hoxyl    in   the   sitle-<-liaiiiH,   4. IS.     Hydro.xy-aldirhytkfl,   437. 

Compotii%iiavithtfunitro-t/rouparulamitU>-ifTvuii(,H9~$$i)     438 

IfitranilinM,  43S.  NitrobenxoTc  acida,  439.  AmiiiobciuoTo 
addi,  430. 


SI* 


COSTENTS, 


ORI«KTATIOXOrAllO»UTICOoilTOCKI»S(3S>-lS7) ■Wl 

Methoda  of  an«ut«lion,  AM.  \\XmiiT.v.'*  principle,  4-12.  Abtiolutc 
dctenninolion  of  powtitin  for  ort/ia-cuntpoiuid.i,  M2.  X^saAyHt: 
detcrminalioa  of  pcwilion  fur  twin -ruinpoiinde,  -144.  Abeolule 
detcnainittioa  of  position  for  fMnt'Coni pounds,  44(1.  Dclcrmina* 
lidfl  vt  pfniiion  (or  the  triMibslilUKKJ  ncd  highcr-Huliniiluted 
dprivati«-vit.  4-1^.     InJIiii'iiiv^of  l)i«  inihHtilui>uiKUiiuA4:li  ottwr, -148. 

TBRFlCfsa  AN t>(!AMi'Mi>HA  (358-363) ' 4S3 

Properties,  452.     Terpmu-s.  453.     Camphor*,  455.     The  cgnslitu- 
tiou  of  thi^  iMpeuM  and  caiiiphor*,  43t), 
DKrtzKNE-NucLE]    l>iiixcTLr  LiKKKD  ToaKTiiKit,  OH  Indkkctlt   bt 

Oamron  C3^-1^) 481 

Difihenyl  (364) 461 

Diphmi/lmrlfione  (365) 462 

TripheTiyinulh/tnf  ami  Uk denvativrs  (366-367) 463 

Triphcnylmcthnnp,  Wi.  Lcui-onnUttchilcKrccn,  463.  Main- 
cliiic'^reen.  -JBS,  Crj-slal- violet,  454.  Panirosaniliiic,  46». 
I'nriUinicunUim-,  ttiH.  Kotuiuilitit.-,  4<i5.  Mu^iita,  ICi'i. 
Mvthyl'ViuUl,  4flfl.  iVniJiut-bluc,  400.  Rosolic  ftcid,  IQfl 
TriplicrvhiiHtliyl,  407. 

DAtm^andilsderivali}f»{3tA-3^') 467 

Dibciu)-!,  4(17.  Sulbciit',  ISS.  Itrnstttii,  4(W.  UydrobviuiuTn, 
4l>8.     Beniil.  408.     Beniilic  acid,  4Q9. 

COHDKKMD  UnNEK-VE-UIMOH  (370-385)      470 

NaphlhaUne  (370-378) 470 

Pn-panilion  (rom  cnal-lAr,  470.  Propertie*.  470.  Coiuttlu- 
lion,  471.  Number  of  8iihBtitutii>n.pti>diio1«.  472.  Substi- 
tution-prod  or  In.  473.     .Wditiim-produirlo,  477. 

Anthraetne  (370  3*3) 478 

Prt-porikiiun  from  coal-tAr,  470  Properties.  479.  0>n«titu- 
tioii.  4"!».  KiiuibtT  of  aubttiituiian-pniducta,  480.  Subati- 
lution-pr<Kb«'l>!,  480, 

PtenanfAfwi*  (384) 488 

Prepfiration  fnim  tvwl-inr.  4.'W.  Propertiw,  4R6.  ConrtllU* 
lion,  485,     Phenonthrfiquituinr,  48fi. 

Fluorantfient.  purrnt.iiH'l  rhryjienc  (iis) 487 

HrrKHf«rm.ir('oMPOL-so8  (386-394) 488 

Pj/ndinf  (386-390) 488 

Preparaliou  froui  coal-t&r,  488  Properties,  4S8  Ccoatitu- 
tion,  489  Hoiuologues,  491  Pvridluecuboxyliu  acidt, 
493. 

Fur/unnt  (301) 496 

CoiiHiitutian,  496.  Pn^panttioD  of  furfurati  denvutives,  498 
I•^lrfll^dlIchyd«,  497.     Pyromurio  Mid,  498. 

/Vrofcfa^P)  •    <M 

PmpnrKltun,    49&     Propprtim,    499.     Cbaililulion,    499. 
PolftaBto-pyrrolo,  400.     DihydropxTTok,  499 


CONTENTS.  XV 

nam 
Thiopkcn  (393) 499 

Pynut^e  (394) 602 

Sj-nthesis    and   coostitutioD,    502.     Pymzoline,    503.     Pyrazo- 
lone, 503.     McthylpbenylpynusoloQe,  503.    Antip>Tine,  503. 
Condensation-products  of  Benzene  and  HBrEEOcrcLic  Nuclei  (395- 

399) 505 

Qutrwiine  (395^396) 605 

Syntheses,  606.  CoDstitution,  506.  Orientation  of  quinoline 
derivatives,  507.  Nomenclature  of  quinoline  derivatives, 
508. 

Isoquinoline  (397) 508 

S}-nthebis  and  coostitution,  50S. 

IndoU  ii9&-399) SOO 

Relation  to  indigo,  509.  Constitution,  510.  Skatole,  610. 
Indigo,  610. 

AuuixitDa  C400-411) 514 

Propertieit  {401) 514 

Extraeiion  from  planU  (402) 515 

Indimdxml  alkaloids  (403-41 1) 616 

ConiTne,  516.  Nicotine,  516.  Atropine,  516.  Hyoscyamine, 
617.  Cocaine,  517.  Morphine,  517.  Narcotine,  518.  Qui- 
nine, 618.    Strychnine,  519. 

Ajubumins  (412-418) 520 

Composition,    620.     Salting-out,    521.    Coagulation,    522.    Dena- 
turation,  622.     Decomposition-products,  522.    Tests,  523. 

CtoMi/fcoIwm  (415-418) S2i 

Native  or  true  albumins,  including  the  albumitu,  gltAulin», 
coagulahie  albumitu,  and  nucleo-aBnimiju,  524.  Decomposi- 
tion-producU  of  the  true  albumins,  including  denatured 
aUmmins,  aVmmoees,  and  pepkmes,  524.  Protelds,  including 
nvcUo-proUids,  hcemoglobim,  glueo-jtroteida,  and  a]bamino\d», 
624. 

Svb^arux8relaiedU}thedlintminoida{4zSi 627 

Bpongiu,  527.  Fibroin,  628.  Sericio,  528.  Sericoln,  528. 
Comein,  628. 


FIGURES. 


FIRST  PART. 
notiBB  rkon 

1.  Org&nio  analyss 6 

2.  Potash  bulbs 6 

3.  Tube  furnace 9 

4.  Victor  Ueter'b  vapour  density  apparatus 14 

5.  Etkuan'b  depressimeter 19 

r>.  Etkuan's  graphic  method 20 

7.  McCoy's  boiling-point  apparatus 20 

8.  Heating  substances  in  an  opeiL  flask 23 

9.  Flask  with  reflux-condenser 23 

<0.  Distillation  apparatus 24 

1 1 .  Fractionating-flask 25 

12.  Distillation  in  vacuum 25 

13,  Fractionating-columns    26 

14,  15,  16.  Vapour  tension  curves  at  constant  temperature 28 

17.  Steam  distillation 29 

18.  Separating-funnel 30 

19.  Filtering-flask 31 

20.  Determination  of  the  melting-point 32 

21.  Pyknometer. 33 

22.  Laurent's  poIarimet«r 34 

23.  Fractionating-column 54 

24.  Carbon  tetrahedron &4 

25.  26.  Asymmetric  C-atoma 65 

27.  Solubility  curve  for  trimethylamine  and  water , 87 

28.  Usual  form  of  solubility  ciir\-e  for  two  liquids 87 

29.  Melting-point  curve  of  the  fatty  acids 103 

30.  Preparation  of  vinegar  by  the  "  quick  process  " 106 

31.  Graphic  representation  of  the  melting-points  of  the  acids  CnH,B_,0,.  189 

32.  Hofer'b  apparatus  for  electro-synthesis 197 

33.  Spacial  representation  of  the  bonds  between  2-5  C-atoms 200 

34 .  35.  Single  bond  between  two  carbon  atoms 202 

36,  37,  38.  Graphic  spacial  representation  of  the  double  bond  between 

two  carbon  atoms 202 

xvi 


CONTENTS.  xvn 

no  CUE  FAOB 

39.  Fumaric  acid. 204 

40.  Dibromoeuccinic  acid 20i 

41.  Maleic  acid 204 

42.  Isodibromosuccitiic  acid 204 

43.  Dibromosuccinic  acid 205 

44.  BromomaleTc  acid 205 

45.  Isodibrotnoeuccinic  acid 205 

46.  Bromofumaric  acid 205 

47.  Erucic  acid 214 

48.  49.   Dibromoerucic  acid 214 

50.  Brassidic  acid 215 

51,  52.    I>ibromobra8Bidic  acid 215 

53.    Acetaldehyde 221 

54,55.   Lactonitrile 221 

56.  57.  Conversion  of  an  optically  active  substance  into  its  optical  isomer,  222 
58,  59.   £mil  Fischer's  spacial  representation  of  two  C-atoms  in  union.  228 

60.   Klectrolysis  of  an  alkaline  copper  solution 232 

fil.    Maleic  acid 235 

62,  G3.   Mesotartaric  acid 235 

64.  Fumaricacid 236 

65.  Ifaeemic  acid 236 

06    Crystal  forms  of  the  sodium  ammonium  tartrates 239 

67.  Rye-atarch 283 

68.  Rice-Htarch 284 

69.  Potato-Btarob 284 

70.  Normal  reduction  curve 336 

71.  Abnormal  reduction  curve 336 


SECOND  PART. 

72.  Habub'b  ■cfaeme  for  primary  and  secondary  reaotiOM 380 

73.  Solubility  curve  of  ben«>te  aoid  in  water 386 


ORGANIC  CHEMISTRY. 


INTRODUCTION. 

1.  Organic  ChemiBtry  is  the  ChemiBtry  of  the  Carbon  Com- 
pounds. The  word  "  organic  "  has  now  only  a  historic  meaning, 
being  derived  from  a  time — the  beginning  of  last  century — when 
it  was  thought  that  the  substances  which  occur  in  organized  nature, 
in  the  animal  and  vegetable  kingdoms,  conld  only  be  formed  under 
the  influence  of  a  special,  obscure  force,  called  the  vilal  force. 
Several  unsuccessful  attempts  to  prepare  artificially  such  "or- 
ganic" Bubstances  promoted  this  belief.  Until  about  the  year 
1840,  it  was  so  general  that  Bebzelius  still  thought  that  there 
was  but  little  hope  of  ever  discovering  the  cause  of  the  difference 
between  the  behaviour  of  the  elements  in  the  mineral  kingdom 
and  in  living  bodies.  Organic  chemistry  included  the  study  of 
those  compounds  which  occur  in  plants  and  animals,  as  well  as  of 
the  more  or  less  complicated  decomposition-products  which  conld 
be  prepared  from  these  compounds  by  various  means.  Among 
the  latter  many  were  known  which  did  not  occur  in  nature,  but  it 
was  thought  impossible  to  build  up  a  compound  body  from  its 
decomposition-products,  or  to  obtain  an  organic  compound  from 
its  elements. 

In  the  year  1828,  Wohler  had  indeed  obtained  from  inorganic 
sources  the  organic  compound  urea,  a  product  of  the  animal 
economy.  This  discovery  was  at  first  regarded  as  of  small  impor- 
tance, for  it  was  thought  that  this  substance  occupied  a  position 
midway  between  organic  and  inorganic  compounds.  For  a  num- 
ber of  yeara  the  synthesis  of  urea  was  in  fact  the  only  well-known 
example  of  the  kind,  such  observations  becoming  more  numerous 


ORGANIC  CHEMISTRY. 


about  the  middle  of  the  nineteenth  century.  The  ^Yiithc-sis  of 
many  sohstancep,  inclmling  that  of  acetic  acid  by  Koluk,  anit  of 
the  fata  by  Blktiiklot,  strengthened  the  con\ictioii  which  had 
gradually  arisen,  timt  organic  cciuiiouutls  aro  fornuid  under  the 
influence  of  the  same  forces  as  arc  moi^ganic,  and  ttat  to  this  end 
no  s])en'iil  force  is  neeessary. 

The  natiirnl  division  between  organic  and  inorganic  chemLstry 
waa  thus  deployed,  its  place  being  taken  by  an  artificial  one.  As 
it  had  been  already  noticed  that  all  organic  compounds  contain 
rsrbon,  the  name  "Organic  Chfniiytrj'"  was  appUtrd  to  the 
ChemiMnj  of  the  Carbon  C'onijmvtulit. 

TIiiKingh  lh»?  nunieroiL''  flisniverien  wliirb  vr^re  made  in  this 
departtiient  of  the  seience,  esprciully  in  CM-rniaiiy  by  Linma, 
WoliLKR,  and  thtir  pupils,  and  in  France  by  Dumas,  Laurent, 
and  (ir.t<nAHi>T,  urKauic  chuni^lry  jn^uaily  acquired  a  totally 
difTcrent  aspect,  and  the  old  division  imo  groups  of  aubstanoe* 
which  had  either  the  same  origin,  as  in  the  case  of  vegetable 
chemistry  or  animal  chemi-^tn,',  or  had  singlp  properties  in  common, 
us  for  example  the  vegelable  airlds,  the  vegetable  bases,  and  ncntral 
vegetable  IkhHc;!,  vanifihod.  Ite  place  -was  taken  by  a  more  rational 
claiwificatiuti.  which  Kraduully  devilupcd  into  its  presMiut  fomi,  and 
is  based  on  the  unitunl  ivlatioi\sliip^  which  &ro  found  to  Q\\»t 
between  organie  comjioimdi*. 

2.  Since  no  e>wential  <)iKtinetioti  IxMween  organic  and  inorganic 
chemistry  now  exists,  and  niimerons  ^ynthesps  have  set  at  rest 
all  doubt  aa  to  the  theoretical  possibility  of  building  up  from  their 
elements  even  the  most  cnniplicated  carbon  com|KPunds,  such  sti 
the  albmiiinii,  the  (luestion  may  arise  as  to  the  reason  why  the 
chcmiBlry  of  the  carbon  com|xmndg  ia  still  treateil  as  a  spoeial  part 
of  the  science.  The  answer  to  lliis  question  is  based  upon  two 
I'caaoni^. 

Fire*,  the  enormous  number  of  carbon  compomids  wliich  are 
knonii.  Tbix  amount^^  to  many  thoueaml^.*  and  is  greater  than 
that  of  the  compounds  of  all  the  other  elements.  Second,  the 
properties  of  the  carbon  compounds.  These  are  either  not  found 
at  all  in  Umj  couii>ounda  of  other  elements,  or  at  least  in  a  much 
less   marked  degree;    for  example,  many   inorganic   com|iounds 

*  Bwentjr-Bvu  tiioscaad  euntpouBda  aro  nwatlonod  la  tlio  dleUoou-y  rooeatly 
jnbllfkfd  by  M.  X  TitcBna. 


Q^'MUTATiVF.  AtiALYSiS. 


Guu  be  axpoutil  lo  Iiigh  ttiin{)€Jiilurv8  witlioat  aDd«rgoiiig  &117 
cWntica]  cliangc.  wborciu  tbc  cu-Wu  coiupouDda.  almost  without 
cxvcption,  »iv  d«coinpoHe<l  at  a  red  lieat.  Ah  &  rciiuU  of  tliiK,  the 
latter  nro  gcDernlly  miioh  loija  stable  Uiuii  ihu  foriiit;r  towards 
chemitsl  and  plijsioil  ivaguou,  aD(]  tbas  differeut  toeUiods  are 
vniptoi,*^  in  Uie  inTestigutiou  of  tbc  carbou  com|M>uuda  aiaA  of 
tht)  inor^iic  uomputinde, 

A  lurtbcr  iwculjurity  lis  tbul  oiuiicrous  or^aic  compouods 
have  exnclJy  the  suinjo  com]>oeitioii,  but  differ  very  much  from  one 
nnoilior  in  propcrtitu.  bur  ciamptR,  up  Lo  tlio  ypur  1900,  iiigbtjr- 
two  compoiintla  of  tJie  formula  C',fl„0,  had  been  discovered. 
This  phenomenon  \»  vmWvA  itoinerism,  mid  is  idmust  unknown  in 
inorganic  cliemiHtrjr,  »  fact  wliivb  iivKcm\ia\«a  an  itivcaiiguUou  of 
the  cause  to  which  it  is  due. 

All  thc«e  raiuoiig  mutce  it  doiiiriible  Lo  treat  the  carbon  oom- 
pounds  iu  n  special  piu-tof  ch«iiiistr\-. 


r 


QUALITATIVE     ASD    QUANTITATIVE     ANALYSIS. 


3.  Inveeligntiou  has  xhown  tbut  in  Ibo  lUHJoritj  of  the  00m- 
|w>uud«  of  carbon,  there  only  occurs  u  very  smalt  number  of 
uleiliODta.  Tbo  chief  of  these  are  carbon,  hgdrogirn,  oxygrn,  and 
Hxtrofftv.  Halofftn  derivatives  arc  leas  riiimeToiiK,  nnil  siihataiices 
eontaiaing  sulphur  or  phosfjhoroua  occur  atill  loss  frequently. 
Carbou  compounds  are  alee  known  in  which  other  elements  are 
found,  but  tliey  are  exceedingly  few  in  comparisou  with  those 
which  contain  only  tbo  oloments  Ttamed  aboTu.  Some  olomcnts 
do  not  occur  in  carbon  compound!. 

[u  order  to  be  able  to  determine  the  nature  of  a  comjionud,  it 
lA  fint  of  all  ueceawry  to  ascertain  what  elemente  it  contains  by 
anbmitting  it  to  •juatHatife  aitaii/tit.  In  the  oaa«  of  the  carbon 
compoanda,  this  is  very  simple  in  theory,  the  procese  Iwing  one  of 
oxidation.  This  converts  hydrogen  into  water,  □itrogeo  is  liberated 
in  the  free  stat«,  and  the  other  clemeula  are  brotight  into  the 
form  of  simple  oompouuds  (carbon  diuxido,  aulphurio  acid,  phos* 
phoric  acid,  etc),  which  can  than  be  detected  by  Uie  ordinary 
tcactions  of  inorgaoio  analysis.    If  an  oigiiaic  compound  contaiiu 


ORGANIC  CHEMISTRY. 


a  halogen,  it  must  bo  osidixed  berore  the  latter  pan  be  dotoctod, 
siacQ  Dto  hnlogcng  nro  not  tiiniatly  split  off  iu  the  fomi  of  ions  b; 
mere  Holutton  of  their  nrgiinic  L'onH)oiiiui8.  mid  t-annot  thwrpfore 
he  recogDiBcd  hy  the  simple  additioa  of  *iU'cr  nilnito.  W'hou 
such  B  compuutid  is  oxidized  in.  jHrMenoe  of  eUver  nitrate,  tbts 
eorrcepondinji  silver  halide  is  formwl.  Other  elemonta  which  may 
be  present  are  found,  aft<?r  uxiilatiuu,  in  the  form  at  cnmpoiinds 
which  ttr«  easily  id(*iitUied. 

For  iinatjticnl  jiurpoee^.  oxidutioii  is  currird  nut  in  different 
vruys,  aooordiiig  to  the  nnture  of  tlio  elmiioiit  wliosi;  pmsonce  in 
suspected.  Copper  oxide  is  generally  used  in  tcstiug  for  carbim, 
hydrogen,  and  nitrogeu.  Tho  »itibslanL-e  ia  mix<ni  with  it,  and 
the  mixture  ia  hontod  in  a  glues  tiibu  8(*iilt>d  at  one  end,  tho  mrbnn 
and  hvdrogen  bemg  oxidised  by  the  action  of  the  oxygen  of  the 
copper  oxide.  Nitrogen  ia  evoWeil  in  the  fru<;  statt.  and  can  he 
recognized  iu  exactly  the  same  way  an  iu  the  qunutitutive  Hiialysiii 
of  nitrogen  (T).  In  the  cue  of  the  hulogens,  sniphnr,  phoepLorue, 
etc.,  it  is  easier  to  oxidize  the  subdtanoe  under  examination  vith. 
ounceutrated  uitrit;  ucid. 

The  method  of  oxidation  ib  a  general  one  for  qualitative  H.naly- 
iis;  it  can  always  ho  applied,  and  yields  perfectly  roliable  result*. 
There  are  iu  addition  other  tuethorls  which  in  many  cutset!  atta.in 
nred  end  more  qnickly  and  easily,  but  as  most  of  those 
Soda  arc  not  of  universal  application,  the  fnJiure  of  one  of 
tliem  to  detect  an  element  affords  nu  certain  indication  of  its 
absence.  In  doubtful  ca^ea  the  ci^uestiuu  inuat  he  decided  hy  the 
oxidation  proccas. 

For  example,  the  presence  of  carbon  can  frequently  be  de- 
tected by  euboiittitig  the  subatancc  to  Avy  distillatiou.  Charring 
often  takes  plare,  or  vapours  are  evolved  which  can  be  recognised 
as  carbon  compound*  by  thi<ir  ann^ll  or  otIi<.'r  properties,  such  as 
barning  with  a  suioky  flame  on  igiiitiou, 

4.  The  nitrogen  iu  many  organic  compounds  can  be  converted 
into  ammonia  by  heating  with  soda-hme,  or  with  concentrated  saX- 
phnric  acid.  Another  method  very  largely  naod  in  teeting  for  thi* 
element  was  aagge.tted  by  Lassiigne.  It  couaistii  in  heating  the 
snlxttanco  nnder  examination  with  a  stnull  piece  of  Bndium  (or 
potassium)  in  a  narrow  tube  scaled  at  one  end.  Should  the  com. 
ponud  contain  nitrogen,  sodium  (or  potaseium)  cyanide  is  formed. 


QO^NTnjnyt  analysis. 


S 


its  presenou  bciug  easily  recognized  by  uoiivertiug  it  into  FniiKiun 
t>lu«. 

Thia  t«et  t9  o&rricdout  aa  foltows.  Tb«  tube  wiiti  its  contoaia,  iiflo' 
liATiiig  been  lieritod  tit  redmsc,  ix  inoinened  in  n  little  wai^r,  where- 
upon it  crftcks,  (iiitl  the  alkiklinc  cyAoidf  which  has  been  rornicd  dia* 
solTec.  To  ihU  is  nddod  jl  clroii  ut  &  Eolution  oonlainin^  a  ferrnuit  nod 
ferric  salt,  and  then  a,  little  dilute  hydrooIiloHc  »dd.  ShoiikJ  nn  nika- 
lino  cjranlde  bo  present,  ic  Ig  conrerted  into  PruMlnri  blue,  Toriuiiig  » 
Uuo  procipilntc  in  tfav  liquid, 


5.  Tlie  halogoiiB  may  bo  recognised  by  heating  the  subatanL-e 
with  qiiicUime,  the  corresponding  calcium  hHlide  being  formed. 
A  very  dclicjite  method  of  detecting  tliem  is  to  iulmdticv  a  littlu 
of  the  compound  on  a  piece  of  eoppcr  oxide  into  u  colon  pIvkk  flume. 
The  corrcspoadiog  copper  halide  ib  formed,  and  Toliitilizes,  impart- 
ing •  magnifiront  green  colour  to  the  flame.  TboBO  tvo  methods 
an  nlwara  applir4ibia. 

Snlphur  can  often  be  delected  by  heating  the  rnmponnd  with 
B  small  piece  of  eodinm  in  a  iiarmw  igiiliinn  tnbe.  Sodium  nnl- 
phide  is  produced,  und  cuu  bo  dutficlod  by  trejiting  tho  reaction- 
mixtarc,  placed  on  a  dvuu  eilvvr  coin,  with  wati-r,  when  a  Mack 
stain  of  eilreritnlphido  in  formed.  Or,  tho  roaclion-mixtnro  may 
b«  extracted  nith  wutur,  iind  sodinm  nitropnietiiun  added  to 
the  Bohition,  which  tlion  actiuireK  a  dnop-viol«t  coionr. 

Ko  mention  ha«  here  been  miido  of  oxygnti,  beninRe  no  (pialita* 
tive  rearition  \s  known  by  wliirh  ib  may  bo  tested  for  in  an  organic 
compound.  Itti  prcecscc  cau  oiily  bo  detected  by  quuntibilive 
anftlysis. 

6.  Following  nn  qualitative,  mnst  come  yuantUaiive  analgnt; 
thai  IB,  the  determination  of  the  qiianCily  of  onoh  element  present 
in  t1i»  compound.  The  methods  n^ed  for  qualitative  nualviia  in 
tnorgnnio  chemistry  are  ofl«n  very  different  from  those  employed 
in  quantitative  detemiinatione;  in  organic  ehomistry  the  methods 
«f  qualitatire  and  ([iiantirative  analysie  are  alike  in  principle, 
«ztdalion  being  madv  use  of  in  both. 

Carbon  and  liydroyen  are  alwavg  estimated  together.  The 
principle  of  the  method  of  organic  analyeia  which  h  ehieAy  asod 
was  worked  ont  by  Liebio  (1803-1873).  It  is  usually  carried  out 
aa  foUovfl.     In  the  combustion  furnooo,  k  (Fig-  1),  is  a  hnrd  gluss 


ORGANIC  CHEMtSTnY. 


tobp,  ah,  open  At  both  ends.  A  e(Kn[det«  dnviiif;  nf  it  is  shows 
in  the  figure  sbore  the  furnace.  It  u  panlv  filled  with  grvao- 
cuppcr  oxkIv,  j^,  antl  with  a  tpin)  nf  copper  gwue,  r^ 
rbich  liM  bem  ou>!txed  br  htsting  to  nellies  in  the  sir  or  in  a 
frtrcam  of  uxYgcu.  About  one-third  of  the  Icn^h  of  the  tube  is 
kft  «mpty,  uhI  into  this,  after  rcoiOT*!  of  the  copper  epird,  a 


pUtinam  or  porcelain  boat,  d,  contiuntnj:  a  vdgbud  qtuutitjr  of  the 
sub8tanc«  to  be  analyzed,  \a  inlrodaced.  The  «nd  of  the  tube  next 
the  boat  ia  connected  with  n  dryinjt-apparatng,  j,  k,j,  in  which 
lh«  air  or  oxygen  is  frveil  from  water-vapour  and  carbon  dioxide; 
g  contains  oonceDtrated  caustic  potash,  h  wda-linie,  and  j  calcium 
p  chloride.  To  the  end  of  the  tube  fnfthest  frnm  the  hi«t  is 
'attat^hed  a  weighed  calcium  chlnnde  tuho,  ^  for  the  pnrpose  of 
collecting  the  water  produced  bj  the  combustion  of  the  subetauce. 

Thewcighfii  potjwh  bnlbe,  m  (shown 
enlarged  in  Fig.  2),  are  wmuected  to 
tliiB,  and  in  them  the  carbon  dioxide 
formed  is  absorbed  by  concentrated 
raiietic  potafl).  The  gasee  enter  the 
appantns  by  the  tabe  b  o»  the  right, 
pass  through  tbo  three  btilb^  con- 
taining jKituiih.  and  ivcape  through 
the  uilw  ir,  which  is  611ed  with  soda- 
iDie.  As  Boon  as  it  is  certain  that  all  the  joints  of  the  apptmtus 
tare  gas-tigbt,  the  burnere  are  lighted,  except  lienenth  thi?  pliirc 
wbora  tho  boat  ia.  Wheu  the  tube  is  hot,  tho  substance  is  biirnod 
by  carcfnlly  heating  this  part  of  the  tube,  while  at  fir&t  u  sloir 
fitroam  of  nir,  imd  later  a  slow  Htream  nf  orygon,  are  IchI  tfarongll^ 
the  dn,'iug>a])paratus  into  the  tube.  The  oxygen  has  tho  effect  of 
hamtng  more  easily  and  quickly  the  purticles  of  carbon  which  han 


Flu.  S. 


QUANTITJTIVS  ANMLYSIS.  J 

depoeited,  and  the  red-hot  copper  oxido  Berrea  to  fuilj-  oxidiio  th« 
ga^otie  (iMompositktii- products  to  carbon  dluxidt-  aiiil  wi4l«r. 
The  iDcreiwe  id  weiglit  of  tlio  calcium  chloridu  tubu  and  of  the 
potadh  bulbs  gives  the  <)umitity  of  water  and  curbon  dioxide 
formed,  from  which  thu  amouut  uf  hydrogen  and  carbon  in  tite 
com|)Ouiid  m&y  be  colcitlntcd. 

Hhunld  the  compound  contain  nitrogen  or  halogens,  a  freeU;- 
rtduced  spirul  of  copper  is  placed  at  the  end  of  the  tube  next  tbe 
absurptiou-Bpparatus  I  oiid  ui.  The  liot  capper  decomposes  atiy 
nitrogen  oxidea  which  may  l>e  formed,  and  which  would  othorwiae 
he  abuirbuil  in  the  pntatih  bnlbs,  and  at  thv  eamr  lime  combiner 
with  and  retains  the  halogens. 

Sonivtuiies  Ihv  atudjvu  in  varriml  out  io  adiffeirent  manocr,  the 
Mifaatanee  to  bo  analyzed  being  mixcHl  wiili  fli]«lv-[>ow(lAretl  cnfp«r 
oxide  and  heated  in  a  tubq  drawn  oot  at  one  end  to  a  finu  [mint  in 
the  Bbapo  of  a  Ixiyonc-t,  and  coaoeoted  at  iho  oilier  u-ith  the  alwirp- 
liou'nppamlus.  In  order  to  di'ivo  over  itilo  tbe  uboorption-apiwratuA 
the  water-vapour  and  carlran  dloilde  nhicli  runiaiu  in  ttio  IuIm  after 
the  combnstioii,  the  poiDl  of  tbo  lube  ia  brokeo,  and  a  atrentn  of  air 
drawn  gradually  through  Ww  wtmlu  appantes.  Sabauuees  whici) 
bam  with  great  dilGcully  an-  mixed  witli  lea<I  chremate  iusleod  of 
eop[K>r  oxhte,  t))o  [Drmor  being  Die  mom  eiiurgelic  oiuliEing-agenl. 
This  nnbatanuc  U  «Uu  uaed  wliun  tlie  compound  conLains  sulphur,  (he 
•  SDlphur  being  oourorletl.  by  btnitiiig  in  mulact  witb  tbe  chromate, 
into  lead  aulfbate,  wbich  ii  »lablo  at  rod  beat.  If  copfior  oxido  is 
UMd.  solptiur  dioxide  \»  fonnsd  and  'm  absorbed  in  tbo  potash  bullie, 
tboroby  iiilrodu^itiK  an  error  iato  ibv  cjtrbou  v»ttinattoti.  ihnoiher 
method  of  retaiiiiiiK  Halpbur  dioxide  coimtitlft  In  1i.ivmg  a  layer  of  lead 
dloxtdo,  I*bO( ,  al  the  end  of  tbe  tub«  next  to  Ibc  absorptton-appn- 
ratux.  Tbia  layisr  i»  gently  liealed,  atid  tnkea  up  all  tba  aulpbur 
dioxide,  with  forauition  of  lead  lulphate. 

7.  Xiirogen  is  uaoally  e-stimated  bj^  Dchas'  method.  A 
weighed  quantity  of  the  subotoncr^ia  mixed  with  finely -powdered 
copper  oxide  and  placed  in  a  tnho  closed  at  one  end.  A  euhstance 
which  on  heating  eaaily  OTolTea  carimn  dioxide  ij  prerioaaly  placed 
At  the  end  of  tbo  tnbo,  magne«iiim  carbonat^  being  often  uK-d 
for  thin  purpose.  The  remaining  spaoo  is  Oiled  with  grannlsted 
cfjppur  oxid(Jf  Stid  a  roll  of  dean,  freshly- reduei-d  coppwr  gauzrU 
pUced  at  tbe  end.  The  open  end  of  the  tube  is  closed  with  u 
imbbcr  stopper  Htbed  with  a  delhrery  tube,  the  end  of  which  dipa 
Bnder  mercury.     Aa  eoon  aa  the  air  hiw  Iteen  dri^uuigit  of  the 


> 


k  ^ 


s 


ORSANIC  CHEMISTRY. 


appantns  by  heating  the  mugnesium  carbonate,  the  front  part  of 
thu  tube,  contaiuiiig  the  copper  Bjiiral  uqiI  tho  granulated  copper 
oxido,  is  hcAtcd.  The  combtistiou  U  then  begun,  acd  thv  evolved 
goees  are  collected  in  n  graduntod  tube  oi^OQ  at  the  bottom 
(measuring  tube),  the  end  of  which  dips  into  tho  mercury  bath, 
and  which  is  filled  partly  with  mercnry,  and  partly  with  couw'n- 
irai«<l  caustic  potiwh  lo  alMorb  the  carbon  dioxide.  The  r«xlucttl 
copper  spiral  haa  the  effect  of  decompoBing  any  nitrogen  oxiJm 
which  may  be  formed.  The  magncsiuni  carbonate  in  again  hctttc^l 
a&  soon  od  the  eoiiibuiitiou  is  over,  tho  ciirboii  dioxide  evolved 
driviiig  all  tho  nitrogen  raniaining  iu  tho  apjurotna  into  tho 
grudu&lvd  tube.  Tht*  latter,  along  witli  the  men-ttry,  pulaidi,  and 
^iK  wliich  it  contaiiiB,  is  then  placed  in  a  wide  c^iindvr  fdli'tl  with 
water.  The  mercury  and  potash  are  displaced  by  the  water,  and 
after  the  level  of  the  lii^iiid  ineide  and  oiitf»ide  the  tnhe  ha«  Ifvua 
made  to  coincide,  the  number  of  cubit!  c^ntimetrea  of  nitroj;en  is 
read  o(T.  From  this  thu  amount  of  nitrogen  in  the  compound  is 
calculated. 

In  many  cti«e«  nitrogen  may  be  estimated  by  a  mcihod  which 
waa  dtacoTerud  by  Kjeuiarl  and  improved  by  Wilfarth.  It 
.epoiidd  upon  the  fact  that  the  nitro^u  of  many  organic  sith- 
nees  is  wholly  converted  inio  ammonia  when  the  compound  ia 
healed  for  some  time  with  cunceutruled  Giilphurie  aoid  in  pre«enDe 
at  phosphoric  nnhydrid*'  and  a  drop  of  mercury,  thu  latter  goini; 
into  soliititm.  Usuully  tliu  mixtiirL-  tlrst  turna  blat-ii,  owing  to 
charring;  uftcr  heating  for  one  ortwu  hount.  a  potut  ie  reached  at 
which  the  li^inid  a^idn  becomes  perfectly  colourlcw.  The  carbon 
h»s  then  been  fully  oxidized  by  the  oxygen  of  the  sulphuric  acid, 
which  III  reduced  to  Kulphurouo  acid.  The  pmcess  is  facilitated  by 
the  mermiry  ftilt,  which  proltably  plays  the  part  of  an  "oxygen 
carrier  "  between  tho  sulphuric  acid  and  the  organic  Bnh«tane«. 
being  continually  converted  from  the  mercuric  to  the  mcrcnroiu 
st*te,  and  then  liaok  again  by  tho  boiling  acid  into  the  mercuric 
state.  :V8  B'ton  IU  the  lii)iiid  him  lK><^)me  colonrle^,  it  i^  idluwod 
to  coul,  dilntMl  with  water,  excetu  of  alkali  added,  and  tlie  am- 
monia distilled  into  a  measured  (|iinniity  of  acid  of  known  screngih. 
By  titrating,  tho  i|aantity  of  nmmonia  is  found,  and  hence  the 
unouut  of  nitrogen.  Thia  nrttt  and  eatnr  method  is  nenalty  not 
applicable  to  compounds  which  contain  oxygen  'inked  to  niiro- 


Ql/MKTtTATtyE  ANMLYStS,  9 

en.     Iq  this  citsa  the  latt«r  element  is  uulj'  pATtially  oonTort««I 
into  nmmoniH. 

8.  The  hnlogens  can  be  eittlmafcod  by  tbo  method  rithc-r  of 
LtEBici  nr  or  CAiiii.'&  In  tlie  former.  Uic  subatiuico  ta  hcsteil  with 
<inicklime,  atid  in  tliolaltcr,  at  a  high  tcmperAturo  with  a  littJo 
conoeutrnted  nitria  ncid  nnil  n  cryntiU  ot  sih'or  nitrato  in  n  ^.alcd 
glaes  tube.  This  is  uurricil  out  withont  risk  in  the  tube  furnw<« 
(Fig.  3),  in  which  the  gUas  tubes  are  placed  in  vrroaght-iron 
CTliodere  with  thick  walU. 


Fig.  8. — Tcbe  Fvrjiack. 

Oabius'  metho<l  can  also  be  applied  to  the  estimation  of  sul- 
phur, phosphoras,  etc,  Non-volatilo  subHiflncM  containing  sulphur 
or  phoaplioniB  can  also  be  oxitlized  by  fiittiun  with  3iitrc. 

9.  Th(!  results  of  a  quaiititutivo  analms  are  oxpreiued  in  per- 
centage-nnmlwrB.  If  the  total  of  tlieae  percentage -numbent  is 
YtiT  nearly  100,  then  no  otiiur  elements  arc  present  iti  tbi-  tom- 
pounil;  but  if  appreciabl,v  leits  than  100,  there  is  aiiottier  olu- 
mcnl  preKut  which  hm  not  been  taken  account  of  iu  tliv  Nimlysis, 
becaoH  there  U  no  suitable  method  known  for  its  estimation. 


IC 


otiCMac  aiEBtBTnr. 


Thm  {II  witig>-— Bnt  of  eajg/m  k 
tkntec  iomad  hj  mihume^g  tht  tocal  el  (be  pewifM  of 
Cl»  Mlbn-  ill  ■mil  froM  IM.  TUi  hm  the  dwdnatape  that 
Ac  OTon  «l  npariflwaA  arc  all  JadaJirf  m  Uw  iftrtntTr-TTini- 

I  an  wmDj  too  lev,  e«b«  to  tke  )•■■  of  ft  Euie 
I  ikioaiji  lk»  varioM  cocnaettona  of  iha  ^faeataa.  Tbe 

an  firaOy  t*o  Llfb,  biMii  oeppcr  oxkW  b 
hyfraaufit.  aad  can  oolf  fae  baed  fna  tnoea  frf  BoiKan  vUli  0nai 
4MotII7.  Ifecaa  crron  baUnw  «ea  aMthcr  iMve  «r  Ina.  an  Umi 
Urn  «aai  «f  aflconey  in  tba  otjfm  ptnsaotaft  to  rthnfailabeJ. 

Tbe  netliod  bj  whirb  tbe  prrecetagc-eoaipoeittofi  and  fonnuU 
of  a  MilMaiiea  are  c&lcnUtM]  from  tba  molts  vi  analrau  u  best 
fzpUined  br  una  or  tvo  euunjtlea. 

tnnt  tUampU.     Tht  fuUovlBc  aamben  van  obuliwd    In  tbe 
saaJjab  of  ■  rabatancv : 
<«»  tt.tmi  f .  Hibilanee  gave  0T4M  g.  00,  and  0-1U8  %.  HiO. 
gl)  0>2170  s.  aufaataoec  gave  0-«4I4  f-  COi  aod  0-13d0  g.  H.O. 

Hbm  |1mt«  an  13  paru  bjr  welgfat  of  0  in  U  {arti  bf  wei^ bt  of 
COi,  awl  S  parts  b/  weichl  of  li  to  18  pnru  bj  neigfaC  of  H(0,  (be 
nnmber  obUioad  for  CU.  must  tia  nmllipliad  by  H  =  ^  to  fiod  tbe 
■mount  of  0.  and  the  Dtuabet  fbutul  for  II^O  by  f,  =  )  to  obtain  the 
■inount  of  D. 

{a)  0>2Sei  g.  HifattauoB  contain  0-9087  g.  C  and  0-0181  g.  n. 

(&)  0  ai70g.  flubntanoBOontait)  0-1740  g.  C  and  0-Olfit  g.  H. 

In  order  tn  oakniatn  from  ibis  tbe  pormotag^nurabera,  tbe  figuree 
fmud  lot  C  aiMl  11  niiiat  bo  dividnl  by  tbe  neigfai  of  siibntuticc  uwd 
la  the  analyiia,  and  tlie  quotient  multiplied  bjr  100.     Tbis  give* 

((I)  80-8X  C  and  7-«  H. 
(ij  CK)-i»  C  and  fl-W  K. 

BltHW  tba  sua  of  Q  and  H  u  67-8  in  (a),  and  87-S  in  (&),  tbe  com* 
pound  aaaljiad  mutt  couuln  oi/gun.  According  to  (a)  tbe  per- 
ocolage  of  thiaelemeol  it  13-3  ;  according  to  (6)  it  in  13-1!. 

The  moan  of  tbe  two  aualysee  giree  tbe  following  {lercentngt^-ooni- 
poditoQ  for  tbe  mbatUMo : 

OBO-T 
H  8-ft 
OlS-4 

The  Atomic  fmiglit  of  carbotkia  13,  of  hydroRen  1,  and  of  oxyg:eQ 
19  ;  la  order  to  find  tbo  ratio  of  tbe  number  of  tbo  atoms  of  theee  4le- 


QUANTITATiyE  ANALYSIS.  " 

ments  in  the  compound,  tbeir  atomic  weigbta  mast  be  dirided  into  the 
perceatage-aumbers.     From  this  we  obtain 

C  H  0 

6.7  6-e  0-8 

Since  tliere  cannot  be  less  than  one  atom  of  each  element  in  a 
compound,  and  since  the  figure  representing  the  aamt)er  of  atoms  must 
alirays  be  a  whole  number,  we  moat  divide  the  above  ratio  by  0-8, 
which  maizes  0  =  1,  and  the  other  numbers  as  follows : 

C  H  O 

8.7  «-0  1 

It  is  evident  that  the  ratio  of  the  numbers  of  the  atoms  is  verj 
nearly  9:9:1,  which  corresponds  with  the  formula  CiHiO.  Inversely, 
if  the  percentages  of  carbon,  hydrogen,  and  ozygen  be  ci^ulated  for 
a  substance  of  this  constitution,  there  is  obtained 

081-3  H6-8  012-0 

which  approximates  to  the  mean  of  the  reanlta  of  the  analyses  given 
above.  The  simplest  or  empirical  formula  of  the  substance  ia  there- 
fore 

CH.O. 

Second  SocampU.  The  analysis  of  a  substance  coDtaiaing  nitrogea 
gave  the  following  numbers  : 

0-2169  g.  substance  gave  0-6170  g.  CO.  and  00685  g.  H,0. 
0-2218  g.  substance  gave  17-4  c.c.  H,  measured  over  water  at  9*  C. 
and  762  mm.  barometric  pressure. 

The  weight  of  the  nitrogen  is  calculated  in  the  following  way. 
Since  it  is  satarated  with  wat«r-vapour,  the  tension  of  this  expressod 
in  mm.  of  mercury  must  be  subtracted  from  the  barometric  presaura 
in  order  to  obtain  the  true  preaaare  of  the  nitrogen.  At  6*  C.  the 
tension  of  aqueous  vapour  is  7-0  mm.  The  actual  presaure  of  the 
nitn^n  ia  therefore  763  —  7  =  756  mm.  Since  1  c.c.  of  nitrogen  at 
0*  and  760  mm.  weighs  1-3562  mg.,  at  75fi  mm.  and  6*  C.  the  weight 
of  this  volume  expressed  in  milligrammes  is 

1-2562  ,34s      ^_^jjj^_ 


1  -f6  X  0-00367      760 

Therefore  the  17-4  c.c.  of  nitrogen  obtained  weigh  1  -3311  x  17-4  = 
91-247  mg.,  from  which  the  percentage  of  nitrogen  is  found  to  be  9-6. 


»a  ORGANtC  CHEMISTRY, 

B;  npplyiDK  tlie  oietbod  dncribcd  in  Ibo  fii«t  csa.iii]>l<>.  llio  per- 
centage oi  c&rtton  a.nd  hydrogen  is  foand  lo  be  0  =  Qfi-0  and  H  =  8-S. 

Tliesainof  thcaoporc«t)tago-t)Uiabenisi8-l,  BO  that  the  perc^ntase 
of  oiygvn  in  the  suhstauoe  ftaalyzed  is  31  -9.  The  perceat&ge-coaipoBU 
tlnn  givcu  \>y  tb«  imalysia  is  therefore 

C  65' 0 
H  8-5 
N    9-6 

On  dividing  ih«so  valaes  by  tho  Rumbcrs  repreeenlinK  the  Atomic 
velglitA  of  11)0  coiTcspuitdiug  eletDonts,  w«  have 


C          H          N 

0 

54         8-5         0-7 

1-4 

Tboee  DamborB  divided  by  U>7  give: 

c       n       N 

0 

7-fl        51          1 

3-0 

Tlieeo  numbora  approximate  very  closely  to  thom  required  by  the 
formula  CtHtKO>,  The  perceutagc-oomposiiioii  correspoDdiog  to  Ibis 
formala  is 

Ces-S  HS-4  17  9-5 

« 

whfob  a^es  we]l  willi  tli»  aiiiilysis. 


DETEEMIJrATION  OP  MOLECULAH   WEIGHT. 

10.  Au  aiialjflis  nnly  gives  the  cmpiric»1  fonnuI»  of  a  com- 
pouiiil,  and  not  ita  molocular  formula,  because  C'^UlOo  Ims  the 
same  pen-i'jiUge-oomjiui-itjtiii  iw  (C,H,jO,)„.  Wlieu  the  i^inpiricul 
formula  has  been  «8c«rt«ino(l  by  analysis,  tho  moiecitlar  weight 
hati  Hiill  to  be  dpt«rmintjd. 

ThU  cannot  bo  decided  by  chemical  mvaiw,  although  it  is 
poaaihle  to  thus  obtain  a  minimnm  value  for  the  molecular  WL-ight. 
For  example,  the  empirical  formula  of  benzene  is  CH.  There  is 
eoiiily  obtained  Irom  benzone  a  H:<>mpoimd,  C.II^Br,  which  ran  be 
reduced  aguiu  to  huuzeite.  It  follows  from  ihU  that  the  molecule 
of  this  mibstanc*  iiiudt  he  represented  at  least  by  C,H^  The 
molecular  fonnuU.  Iiowcvit.  could  utiiu  be*  C'„1I„.  or,  hi  general, 
(C,H,)„;  tiio  broiriiiif  compound  would  thcu  have  the  formala 
(C,n4Br)„.     Asaumiug  the  formula  lo  bo  C„H„,  that  of  the 


DETBRMiNATlON  OF  MOLECULAR  WEIGHT. 


U 


brnmine  com]>otiiid  would  bti  C,jII,,nr,.  It  in  (evident  tlut  in  this 
cace  two  Itydrog^i  atoms  would  hnvo  Iimd  dirn;;tly  repliicod  by 
bromine,  nnd  p:(pcrim<.<nt«  would  Ijo  mado  for  iUv.  par|>o»c  of 
obt*iniiig  C,^„Br.  Should  these  not  o-ttflin  the  desired  result, 
tho  probabilily  that  the  nirapler  formnlit  ('^HjHr  ig  correct  would 
be  iiicr«i«ed,  aUhonf;h  it  would  not  Iju  jierfoccly  eetablidied, 
because  it  might  happen  that  tho  conditions  neceesni^  to  the 
fonniition  of  the  compound  t'„IJ„Hr  hud  not  been  fonnd.  The 
chemical  method  only  fiimiehns  us  with  »  proof  that  the  molecnie 
of  Itenzeue  cannot  be  auittUer  tlian  that  c3:pre8«od  by  the  formula 
C,H,.  It  is,  howeT#r,  impoesiblo  to  daeide  in  this  way  whether  it 
is  a  multiple  of  thig  or  not. 

In  order  to  ueertaln  the  rent  molecniar  weight,  physical 
meihoda  miist  lie  mndenae  of.  These  consist  in  the  determioa- 
tion  either  of  the  specific  gravity  of  the  ooinpound  in  the  K"<w-uur 
etate,  or  of  certain  vahieti  which  depeud  on  the  oeuiotic  prwtiura 
pi  th«  Bubstuncie  iii  dilute  solutiou.  UwUl  t>e  seen  later  that  thero 
is  a  etose  coimectiou  betweeu  tlieiM  ajipureiiUy  totally  dilTorent 
muthods. 


DeterminatioD  of  the  Molecular  Weight  ttttm  the  Vapour  Density. 

11.  According  to  AvooAlnio*s  h»w  ('*  Inorganic  Chctnielry,** 
SI,  3S,  and  36).  oriual  volumes  of  ditToreut  gues  taeosured  at  the 
satuo  tempenitun*  ;md  pressure  contain  the  same  number  of  mole- 
cules. From  thiit  it  fullown  that  the  wcighte  of  i\\v  molecnles  of 
tbeee  gneee  niuet  stand  in  the  same  relation  to  one  unotlier  as  the 
weights  of  these  et)ual  volumes.  Since  the  atomic  weight  of 
hydrogen  i»  taicen  aa  unity,  aud  a  molecule  of  hydrogen  eontains 
two  atoms,  the  molecndar  weight  of  h^'drogeii  is  2.  Ifancquai 
volume  of  anotlwr  p\»  under  the  same  oonditionB  as  to  temperatUK 
and  prnwire  weigh  a  timtst  as  m\u:\\  jis  hydroguu,"  then  itg  mole- 
cules nUo  will  weigh  a  times  us  much,  aud  the  molecular  weight  of 
H  the  gtts  will  be  'ia. 
^^  In  order  to  be  able  to  calcuUte  the  vapour  thnsity  (the  specific 

I  gravity  of  the  substance  in  the  gaseous  state),  four  i»anlitiefl— the 

I  weight  of  sulwlanco  converted  into  the  gaseous  state,  the  volume 

\  of  the  rcsnltiug  vapour,  the  temperature'  at  which  (he  volume  is 

^^L        moacored,  and  the  barometric  pressure — must  be  known. 


'am  tlivnttura  itw  spodOc  gnrhj  oj  the  gfta  r»1»nt4  to  lifdrngwo. 


ORCMNK  CHHMISTRY, 


'^ 

^ 


IS.  ViLpoiir  density  is  lutuilly  d«ti>nni[K>(l   br  u  metboil  sn^- 
geeted  by  Victok  Mkyck-      llie  nppamtns   tnK-'ussiiry   fi>r   tliu 

(Fig.  4-)  cuiuiiDU  uf  H  glusji  itibo  i 
witli  an  iiitttnuil  (lismcUT  of  ultoiit 
4  mm.  This  hibc  u  cXotxA  iil  tin* 
top  with  a  MAppcr,  «nct  Iim  iin<)cr- 
iipot))  »  wider  crlinilrirul  ]M»rtion 
-H  uf  nbout  200  cc,  ca|Micity,  rktu^d 
at  the  lon-cr  cuil.  Nuur  thp  top 
of  thu  tube  in  iw'alcil  ou  i\  <3(*liTery 
tul>o  /  fur  the  giie,  wuli-h  is  rol- 

(■■^^^  1ect«d  orer  water  in  ii  ffradu*le4 

^^/  tube  g.     Tlis  ftppantus  iii  partly 

\l  surroutidetl    by   u    niile   g]a»t    (or 

\^  tncdl)   jiioket  a.      Thia  foiiiains 

^  ^^  tt   liquid   of   bif^ber   builing-point 

I  V^V  ^'**"  ^^'^^  ^^  '''^  mbetaacc  wlioee 

■  ^^^    TBponr    density    is    b«in(r    dot«r- 

mined.  Tbia  \i<fnA  in  hfat«Ml  to 
boiling,  Home  of  the  nir  in  b  beiiin 
in  mniiefiuence  cx[icll(<d.  A  {toiiit 
ifi  soon  roMchfd  whrn  no  more  air 
escupuB  from  tlic  drlivpry  tnhe. 
that  in  th*  wjdM  ptirt  of  tiie  tube 
hftving  H  ooD9tuu  temperature, 
very  nearly  eqnal  to  that  uf  thi> 
vajKinr  of  the  boiling  liquid.  Tbp 
pvdnsted  tube  ia  now  fiUed  vith 
water  and  plaml  ovt'r  the  opoD 
end  of  the  delivery  tube  /.  The 
atopper  ia  then  witudrawn,  and  a 
weighed  quantity  of  tbe  subHt»n<->e 
to.  t-VtcTOR  Metrr'o  VAFOca  undpr  esaiiiinauou.  usually  eu- 
uasMTT  ApruuTPfc  closed    in   a   lilUe  glass   tnbe,  ll 

'dmppLtl  into  the  apparatus,  anil  the  stopper  replaced,  care  being 
takt<n  to  mukv  it  aiT-tight.  The  eabmwiM  Ta|M>rises  <)uickly  in 
tb«  heat^  wide  portion  of  the  tube.  It^  v!\[tour  cxpelti  air  from 
i\\v  apparatus,  wiiioh  is  collected  in  the  graduated  tutje,  and  is 
equal  in  vulume  to  that  of  tlie  vapour  itself.     While,  however,  the 


OETERMIN^TION  OF  MOLECULAR  It'F.IGHT. 


»5 


ftir  ill  fche  liot  purt  of  tUu  appiiratuB  buH  tbe  local  tempeniturt-, 
in  the  gmdiiAtod  ttthv  it  ikcqiiirug  iho  teuip«nitnro  of  tlio  latter,  go 
thikt  thix  nuii^t  Ik*  takvn  iiilo  uecontit  in  milking  tlic  palciilntjoii. 
The  exjwriiiieiit  gireK  a  rnluino  which  is  <y[H!il  lo  that  which  th* 
wciglifd  portion  of  llie  mibstimco  in  the  fon»  of  vapour  would 
orriiipy.  if  it  were  possible  to  conrort  it  into  a  gas  at  the  ordinary 
tt'iitperature  anil  under  the  linminetric  presfiiire. 

For^ase  of  mauipuUtion  thiii  method  Ieuv«e  nothing  to  be  de- 
sired. It  pot!se«<ue&,  iiioroover.  iho  great  lulvHiiLiigo  over  ihu  otliiT 
tiii>lhoilB,  that  it  is  not  iieeustutry  to  know  the  tenijtonitnro  lu  wiiich 
the  upimntns  1ia8  been  heated,  since  uo  n»e  ii  nmde  of  this  in  the 
cHlnilittiun.  It  is  only  neoeBnary  thai  the  tempcnttnre  ahotild 
reuiiiin  conttfant  during  the  ehorttiine  occnpicd  by  the  experiment. 

The  result  is  calmlated  in  the  following  way.  Suppose  thiit 
g  mjf.  at  tlie  BubKtanee  wern  weighed  onl,  and  yielded  V  e.f.  of 
air,  ineiuuiriMl  ovor  wuter.  with  the  level  the  euiiit!  inside  and  out- 
side the  tube;  aiippose  fnrther  that  the  bnrometno  pressure  ucrt) 
If,  the  tcmperoture  /.  and  the  tension  of  aqneoiis  vapour  h.  theu. 
undiT  u  presAure  ot  II  —  h  mm.  and  at  t°,  <j  iiig.  of  the  suhstaneo 
would  occupy  a  volume  of  Tec,  »o  tlint  under  these  conditions 

the  unit  of  vohimo  (1  c.c)  would  eontain  -^  mg.  of  the  BubsUince. 

Ono  e.c.  of  hydrogen  under  ft  —  h  mm.  of  prewinre,  and  at  t', 
weighs 


0-0805 


//-A 


1  -f-  0-00M71  ^     7iM    ' 

frnni    which  it  follows  that   tlie  vupour  donailjr  D  compared  to 
hydrogen  is 

ff        1  +  0-OU3«T(         760 


O  =    f  .-  X 


0-U890 


u~y 


The  niolvcalar  weight  M  being  twice  the  density, 

J/=3A 

Victor  Metks'8  method  caTinot  nx  a  rule  be  spplied  to  sabArances 
which  decompose  when  boiled  under  n  pri'ssuro  of  one  niitio>pliei'v. 
SulMtiLiioesof  thix  kind  cnii  often  Imi  convened  iuio  v»|)oiir  Without 
decomposition  undor  diminished  preeaure.  To  doieraiine  tht-  vnpour 
density  of  luch  itub!tin[ii.-c«  DoruAXK's  method  innj-  tw  employed. 
ThU  win  in  genoTnl  iisn  up  in  Ihe  time  of  Viptok  Mevrk's  di«oov«r]r, 


l6  ORGANIC  CHEMISTRY. 

but  it  Is  now  Bcldom  eioployctl,  as  it  is  much  more  Gomi>Iicatcd  thua 
Ilia  Ialti>r.  lu  HoFM^N^'g  molliwl  a.  w^iglivil  i}uiLTititf  of  ttic-  sub- 
stance, contained  in  a  verj*  siuall  bolllo  intli  a  si^und  glass  Alopi>er, 
is  introduced  into  tbe  vacuum  of  a  baromeLrJc  tul>e.  dividet]  into 
Ivuthsof  a  culjio  cuutiiuctre.  Tliia  tube  U  aurruuuiJcc]  with  u  gliuui 
jaekvt  through  wlilch  ih  jiKSsod  itiv  vn|Hiurnf  a  boiling  liquid,  tbe  boil- 
ing-point of  which  is  higher  llinn  thai  of  tho  substance  iu  thf<  vncinini. 
The  necessary  data  for  oaJovlaliiig  ilia  vapour  lieusity  are  oblniiiocl  by 
rewlinx  the  voliimo  which  the  snbAtance<>ci:u[iiesin  lliegaHcouKHiAii-. 
tho  height  »r  tbe  iniTvury  In  tho  tube,  lb«  ntuiosphorlc  pressuro,  and 
tbo  tompcrnturo  uf  the  appnratus. 


Seterminatioii  of  the  Molecular  Weigbt  from  the  Lowering  of  the 
Freezing-point  or  the  Raising  of  the  Boiling-point. 

13.  In  *•  Inorganic  ChcmiBtry"  (40-43)  reforonco  ia  wade  to 
the  faet  that  solntiong  pontain<?<I  in  a  vessel  made  of  a  eeiui-penne- 
ahle  material,  which  BeparRtcs  them  from  the  solvent,  exereise  an 
osmotic  presstiif;  these  solutione  obey  the  lairs  of  Boyck  auil 
ffAY-LrssAC.  It  in  also  stated  that  tlie  nnmerical  valne  of  the 
osmotic  pressure  is  equal  to  that  of  the  vupour  pressuro.  In  other 
wortJs,  whenever  a  certaiji  quantity  of  ii  mihytatiOL'  in  tiiv  gaseoua 
Btate  occn|)ieB  a  glveu  volume,  it  oxercises  a  vajioiir  pressura  which 
i-i  exactly  etjual  to  the  oMuotic  pre^tire  uliich  would  be  ohtaiiu'd 
by  (liKBolving  the  same  weight  of  the  substance  iu  a  liquid  and 
diluting  to  the  c<ume  volume. 

Accordiugly  the  law  of  Avogadro  holds  good  for  dilnte 
eolntiotie,  for  BupponJug  wb  liavo  an  equal  number  of  mnlecnlcs 
difwolved  iti  i-qual  vohmiofi  at  the  sniua  u^mptTaliint,  tht-u  we  know 
from  the  equality  uf  tho  vnpotir  and  osmotic  pressiircg  tliai  t^aeh 
will  exert  an  exactly  identical  osmotic  pressure;  and,  inversely, 
tboTe  will  be  Lhti  eame  number  of  molecules  of  the  diseolved  £uti- 
etatic«  contained  in  equal  volnmefi  of  the  solvent,  undor  like  con- 
ditions of  tenii>orature  and  osmotic  pTemure. 

Wo  haro  her*;  a  very  impurlant  extension  of  th its  law.  For  it 
ia  possible  not  only  to  compare  the  weights  of  equal  volumes  of 
gases  at  tlio  same  temiJurature  and  pressure  with  one  another,  and 
hence  (o  calculote  the  molecular  weight;  but  we  know  further,  that 
iu  tho  cNso  uf  eolutions  at  the  same  temperature  and  with  the  same 
oBntotto  pressure,  Lho  weights  or  the  BuhAtaneeit  ])re»ont  in  equal 
volumes  of  the  solution  nre  proportional  to  their  molecular  weights. 


DETF.RMtSjtTlON  OF  MOLECULAR   UTEtGHT. 


»7 


•Tiist  aa  the  molet'iiliir  weight  of  gikieoua  snbatiuicM  is  Hrrived 
at  by  (letfrtniiiing  their  teraiieratiire,  pressure,  wuighl,  mtiJ  vol- 
im>«,  fto  for  dilute  Bolwtious  this  is  obtained  by  detirruiiuiug  lh« 
Tolnmc  uiid  ttimpfrutun>  of  thu  Bolution,  together  with  tho  r^uitn' 
tity  of  siihtiUiiiL-i!  iIiiuluIvlhI,  aud  the  {ijtmotir  pressuTO.  The  molec- 
nJiir  weights  ot  »11  ^iilMtuncen  which  ure  Holublu  in  iiiiy  liquid  can 
ht  determined  in  this  wuy,  aud  mice  many  mere  ftiihetances  are 
Gotntile  thiui  urc  ohlaiiiiihk-  in  thf  form  of  lapnnr,  it  is  now  pos- 
liblo  to  dotcrmiiiu  iIk'  mwk-ciilar  wcijjht  vl  u  much  grcutcr  niimher 
of  eompoundx  th:tn  wim  prcviou-ily  the  eagf. 

There  is,  howevpr.  a  dlfiinilty  of  n  practical  nature;  a  direct 
determination  of  the  oKinirtie  prpraurc  ik  hy  no  niuanB  o»«y.  This 
woald  indeed  malce  the  method  alinoHt  nsetexs,  if  it  were  not 
for  the  fact  that,  in  order  Ut  drterminn  the  molecnlar  weight  it  is 
stiflicient  to  observe  whether  two  seliitions  have  the  snme  »»[iiotic 
preesare.  witfa<jut  knowing  its iibsoliue  value;  because  A\oaADRO's 
law  odIv  roquir(>8  timt  tho  ro'.umc,  tcnip(<ratiiTe,  and  preeetire 
(oGmtitie  or  gaseous)  shiill  ho  equal,  apnrt  from  the  quoHtiou  »f 
what  the  absolute  values  of  tLe-8c  (luaiititles  iir»,  so  long  ax  they  do 
not  exceed  certain  limits.  It  is  ea«y  lo  measure  {|u&utltius  wbiob 
arc  proportional  to  the  osmotic  pretisiire,  and  to  infer  from  tlieee 
whether  there  id  cqnality  of  oamotjc  pressure  or  not.  Thete 
quantiti<H  are  the  hHvri»ff  t>f  the  frettivg-^o'ini,  and  the  raiting  of 
the.  boiling-point,  or  the  differenoes  between  the  freeziiig-jminla 
and  the  boiIing-poiul«  resiiectivoly.  before  aud  after  tlie  jtubstunoe 
liEH  hueu  diMolveJ,  tho  effect  of  which  ia  to  lower  the  freezing- 
point,  and  to  raise  the  boiling-point,  of  the  Ailvent  ("iDorguoio 
Chemistry."  42  and  43). 

14.  The  lowering  of  cho  freeziog-point,  and  the  raising  of  the 
boiling-point,  funmh  a  meanii  of  determining  whether  sulntiona 
ore  iivioKif-,  i.e.  whether  they  have  the  same  osmotic  preajtiire. 
The  frcexing-pouit  of  u  aiiheftance.  phenol  for  example,  ia  astwr- 
taioed,  and  a  gramme-molecule  of  a  substance  of  kuown  molooiilur 
weight  is  disaolvwi  in  a  known  weight,  and  hence  in  a  known 
volume,  of  the  Bohent.  This  lownm  the  freesting- point  by  a 
certain  amount,  wliieh  is  always  the  name  for  the  same  solvent,  no 
nintter  what  the  tnbstanre  may  he,  provided  that  the  volitmo  of 
Mlutioii.  contsining  one  granimc-molucuh-,  la  the  Riime.  Tliiii  ia 
line  to  the  fact  that  such  eolutioua  uru  isotonic.     Tho  lowering  of 


i8 


ORGANIC  CHEMISTRY. 


the  freezing-point  eaiieed  by  a  gramme-niolecule  is  therefore  a 
constant  for  this  solvent.  If  a  I<^  solution  of  a  substance  of 
unknown  molecular  weight  Mbe  made  in  phenol,  and  the  lower- 
ing of  the  freezing-point  of  this  determined,  which  we  will  call  A, 
then 

AM—  Constant; 

because  the  lowering  of  the  freezing-point  is,  between  certain 
limits,  proportional  to  the  concentration. 

It  is  easily  seen  that  this  formula  is  equally  applicable  to  the 
raising  of  the  boiling-point.  M  is  here  the  only  unknown  quantity, 
and  may  be  calculated  from  this  equation. 

Example.  If  phenol  is  used  as  the  solreut,  it  has  been  shown  by 
numerous  determinations  that  the  product  of  the  lowering  of  the 
freezing-point  of  a  1^  solution  of  the  substance  by  its  molecular 
weight  is  equal  to  75.    We  hare  then  for  phenol 

AM  =  76. 

In  the  case  of  a  substance  whose  ompirical  formula  is  C-H-K,0,  the 
lowering  of  the  freezing-point  of  a  2-7S!t  solution  of  the  substance  in 
phenol  amounted  to  0-713°.    In  the  case  of  a  1%  solution  the  lowering 

would  have  been-rj^-Ur  =  0-288;  therefore  A  =  0-258  from  which  it 


8-75 
follows  that  the  molecular  weight  is 


0-258 


=  391. 


Since  CiH.NiO  corresponds  to  the  molecular  weight  135,  and  that 
of  CmHmN.Oi  to  270,  the  latter  comes  nearest  to  the  molecular  weight 
found,  so  that  double  the  empirical  formula  must  be  assigned  to  the 
compound. 

The  constants  for  the  lowering  of  the  freezing-point  [molecular 
lowering  of  ilie  freezing-jwtnt)  for  a  nitmber  of  solvents  ore  given 
in  the  following  table : 


Solvent. 


Wiiter 

Acetic  add  . . 

lleiizene 

Niirolicnzene 

rliennl 

Uretlinii? 

Stearic  acid. . 
p-Toluidine. . 


Moln.'UlHr  LoneririK 
of  the  FrepE[iif(-poinl. 


19 

39 

53 

70 

75 

61-4 

45 

62-4 


lie]  ting-point. 


0° 
16. 5° 

5° 
89-6° 
48.7' 
53° 
42.6' 


DETfiRMWATMN  OF  MOLECULAR   WEIGHT. 


»9 


m 


The  Itusl  lour  solveuti*  are  very  uacfut,  and  an-  better  than 
glaciftl  icctic  aoid,  which  is  etill  often  oniploycd,  becniiBo  ther  are 
not  hyproKpnpic,  iinJ,  having  mt'lting-pnintg  higher  thiiii  the  ordi- 
nary t^mpcmtiirc,  obviate  the  nprPBsity  for  a  coflliug-agoiit.  lu 
addition,  their  contitantii  are  high. 

Tha  constnuts  for  the  inimng  of  the  boiling-point  {tnoitcnlar 
ruiting  of  tht  boiliuff-jioinf)  arc  il  for 
etlier,  11*5  for  ethyl  alcokoi,  3(!-7  for  bm- 
teiie,  'm-*>  for  chhrcform,  eto.  Thcs& 
nnmben  are  on  the  whole  nitu'h  eniallor 
than  those  for  the  molecular  lowering  of 
thw  (!**]£ i II g-jwint,  Tlie  extent  to  which 
the  Imiliiig-point  is  raiHeif  \s  therefore  lesa 
thttu  that  to  which  the  freezing-point  U 
flsproMed,  from  which  it  follows  that  the 
latUrr  detorminaliuu  givvtt  groater  accu- 
racy. 

IS,  Kykmam  has  constructeil  an  ap- 
jtarutii?  by  wliich  tlio  depreesinii  of  the 
freosing- point  may  be  catiily  dett^nniiied 
(Fig.  5).  This  coiisialH  of  a  smsill  tliiT- 
nioniHti'r  divided  into  twvnliethH  of  a 
degree,  to  whieli  la  attachtNl  a  little  tlank, 
as  nhowa  in  Uic  llgure.  The  whole  U 
contaioi-d  in  a  ^laB8  cylinder,  is  htdd  at  the 
top  with  a  stopper,  and  enpported  under- 
Qcnth  on  cotton  wool.  The  ]attcr  ha^^  th« 
efToet  of  making  the  cooling  take  plare 
more  slowly,  i«ince  it  in  a  bad  couductur  of 
beat.  A  weighed  qutuitity  of  the  aolrent  ia  placed  in  the  fktik, 
and  its  frcexing-i^tint  determined,  Thi'ii  a  known  weight  of  the 
sabntancc  is  iutrodui-'i-d,  and  the  fit-czirig- point  agiiin  obeerved. 
Id  IJUB  waif  a  dcprcmoii  of  the  fre-cjin(i:-poiiit  is  obtained,  from 
whieh  A  may  bo  caleuhit«{]  as  in  the  example  givon  on  p.  18. 


<£^^ 


Pia.  S.— KraMAiVv 
DariiEeaiuBTKit. 


The  lawa  of  otmotiD  pressnra  only  liold  good  wben  ihe  solulioris  ikr« 
ver7  dllnte.  and  the  nnino  is  tru«  of  tlio  uiiiutloD  A^  =  Conat.,  ainoa 
it  b  dorivw)  from  ih«e  lawa. 

Il  is  uoi  nlriotlj-  ovrreuL  to  di-lerniiii»  A  by  tupiina  of  a  solution  of 
ftnite  concentration,  iw  was  d»ii«  in  (lio  omttaplu  on  p.  IH.     In  ord«r 


ae 


ORGANIC  CHEMISTHY. 


to  determbie  Jf  acotiratety,  tlie  ralu«  of  A  otiuuld  b«  derived  from  & 
Hdmion  of  inflDite  diluMon ;   hut  lu  ihiH  H  not  piias:bli>,  Etku^x 

liiis    (Iciscribcd     the    fnltowiiii;    graphic 

method  of  determifiiog  A  for  ea«b   a. 

Boliicton.       A    ll 

del'TTiilDnd    for 

threoor  fourcou- 
oiiiitrat  ions,   iiud 

the    vaJuRs    ob- 

tniiiod  urn  repn- 

HCIltClI      ^fiphlo- 

nUv  lu  in  Ftg.  8, 

i  n    nliicb    t  h  o 
and  thoao 


Fvi,  A. 

valum  of  ^  RTc  ttia  ordinntes, 
of  ttie  i)crceiittig(;-Hlrcii|i:t.)]  of  Lite  aolmioits 
are  tbu  atwoisBu:.  Etkujik  states  tliat  iii  n 
vecy  gmt  nutn;' cases  tbe  lino  nljiob  con  bo 
drawn  tliroD|{h  ibe  tops  of  tlio  ordinuies  is 
very  iienrly  s.  alraight  one.  If  il  is  prmlucod 
(111  tt  cuu  the  ordiniite  O^i.  OP^  givea  tba 
vnlue  of  A  for  infinite  dilution. 

For  doterminiiig  the  niiaing  «f  the  boU- 

tng-point,  MrCoT  has  oonstnictcd  a  Yeri*  oou- 
iTenient  appiinxtiig.     It  coiwiats  of  two  veseols, 

A  and  B,  fitted  tightly  togpr.hcr.     Tho  iiinor 

tub©  A  is  gradimtpd  near  the  lower  end,  and 

is  Joined  to  a  narrow  tube  «ft,  opening  to  the 

exterior  at  a.     A  side  tulio  c  \nuh  from  the 

nioutli  of  vl  to  a  condcnsor.     Tho  jacket  B  U 

onV*y>d  at  the  bottom,  and  hnx  a  i<ido  tube 

rf,  cloaed  by  a  rubber  tube  and  piucli  elamp. 

Abotil  50  c.c.  of  the  pure  solvent  and  a  Kinall 

piece  of  day  tila  (to  promolB  Tegular  boiling) 

ar«   pUc«d    in   the  jacket,  and  12-lG  c.c.  of  tho  solvout  in  tho 

inner    tube.      The    liquid    iu  the  jacltet   i»  hcatctl   to   bojliug, 

and   its  vai>otir  warma  tho  other   liquid.     Ae  eoou  us  the  latter 

bcconiM  hot,  the  vapour  in  the  jaekot  foreta  ila  way  through  ab 

and  raises  the  tcm[)eratare  of  the  liquid  in  the  graduated    tube 
^to  boiling,  whereupon  a  slow  diHlillation  into  the  condenser  takos 

place.     Superhotttiug  is  thus  avoided.     The  reading  miiy  be  taken 

vithin  fivo  t»  ten  minutes  from  the  begiuuiug  of  tlic  operation. 


Pio.  7,— MCOOT*  BotL- 

1X8-  IVIINT     ApPARA- 
THH. 


THE  ELEMENT  CARBON.  21 

On  coolingi  d  is  opened  to  prevent  the  liqaid  from  being  aucked 
out  of  the  graduated  tube.  The  boiling-point  of  the  pure  liquid 
having  been  found,  a  carefully  weighed  portion  of  the  Bubetance 
whose  molecular  weight  is  to  be  determined  is  introduced  into  A, 
the  thermometer  and  cork  being  temporarily  removed  for  tliia 
purpose.  Ae  Boon  as  the  boiling-point  of  the  solution  has  been 
determined,  the  boiling  is  stopped,  the  thermometer  removed,  and 
the  volume  of  tue  solution  observed.  The  formula  is  tlie  same  as 
that  given  above,  volume  being  substituted  for  weight,  and  the 
constant  calculated  on  that  basis.  Eykman's  graphic  method 
(p.  20)  of  finding  A  for  infinite  dilution  may  he  applied  in  this 
caae  also. 


THE  XLEMEKT  CABBON. 

16.  Carbon  occurs  in  three  allotropic  forms :  diamond,  graphite, 
and  amorphous  carbon.  For  a  description  of  these  the  reader  ia 
referred  to  "  Inorganic  Chemistry,"  176-179,  which  deals  also 
with  the  compounds  of  carbon  with  metalloids  and  metals,  as 
well  as  with  the  determination  of  its  atomic  weight.  It  will 
therefore  be  here  sufficient  to  refer  to  certain  facts  regarding  the 
molecvU  of  carbon.  There  is  no  doubt  that  this  consists  of  a 
great  number  of  atoms;  how  great,  has  not  yet  been  ascertained. 
It  is  supposed  that  there  are  more  atoms  in  the  molecule  of 
graphite  than  in  that  of  amorphous  carbon,  and  more  in  the  mole- 
cule of  the  diamond  than  in  that  of  graphite,  because  grapliite 
and  diamond  are  more  difficult  to  decompose  by  chemical  means, 
and  because  their  specific  gravities  are  greater  than  that  of  amor- 
phous carbon. 

The  determination  of  the  vapour  density  of  carbon  is  impossi- 
ble, owing  to  the  high  temperature  necessary  to  convert  it  into  tho 
state  of  gas.  The  depression  of  the  point  of  solidification  whicli 
carbon  causes  when  disBolved  in  molten  iron  cannot  be  determined 
with  sufficient  accuracy,  because  no  method  ia  known  of  measuring 
differences  of  temperature  of  one-fiftieth  to  one-hundredth  of  a 
degree  at  the  melting-point  of  iron.  Moreover,  the  phenomenon 
would  be  complicated  by  the  fact  that  iron  enters  into  combination 
with  carbon. 


22 


ORGANIC  CHEMISTRY. 


It  can  be  shown,  however,  in  the  ^ctUowing  ways  that  the 
number  of  atoms  in  thu  nioleinilti  nf  [■arbon  i»  a  largo  one.  When 
amnrplious  ciirbnn  \&  oxitlizcd  wilh  imtueniiim  jwriuHngiinste, 
mtUUi';  adtl  is  fortnoil,  contitining  twolvo  Atoms  of  ctirbou  in  the 
molecule.  Tlij))  iiinkc-s  it  to  n  (wrtnin  extent  probable  Ibnt  tlie 
muk-t^iilo  of  carbon  contains  at  U-ii8t  twelve  atoms,  bocaiiso  wlicu 
organic  compoimde  a.n  oxidized.  siibatAiiccg  are  formed  wliich 
ueiirly  always  contain  eitlu^r  a,  smaller  or  the  same  nnmbc^r  of 
carbon  atoms  in  the  niokwulo  as  tbe  Biibstnnce  whicli  haii  been 
Bubinitled  to  oxidation.  For  the  foUovriiig  i-ea«0D8,  however,  it 
is  bolicvMl  tlint  the  number  ot  atums  in  the  molecule  at  cjirbon 
is  greater  than  thin.  Among  the  products  obtained  by  leiuling 
marsh  giis,  CU,,  through  a  heated  uibe,  it  found  ethylene  fftit, 
C,n,.  Whoa  this  i^  treated  in  the  mme  way.  acetylene,  t^'.U,.  i» 
formed,  which  in  ite  turn  yields  liirnzene,  C,!!,.  When  benzeiic- 
vapoiir  is  led  througli  a  white-liot  tube  it  forms  Hup/ifhitUtte, 
C,„H, ,  and  pt/re>if,  f'„H,„,  etc.  On  heating  naphthalene  or  pyreno 
to  a  fitill  higher  temponilure  In  ahsenire  ot  air,  carbon  is  pwidncod. 
From  tltiH  It  is  seen  that,  ax  the  temjierature  risen,  compounds  are 
formed  conlutning  more  carbon  atoms  in  tliu  molecule.  This 
mnkea  it  probable  tliat  the  final  product  of  Ihceo  reactioMs,  curbou 
itoctf,  contains  a  coasidenibly  givutvr  number  of  utonni  in  its  undv- 
enic  than  the  nuniber  of  enrbon  atomfi  in  the  molecule  of  pyrciie. 

A  thirJ  l^roof  of  the  greiit  number  of  hUiiiir  in  the  molecule  of 
cnrbon  is  found  by  examining  the  bnitiiig>pointtt  of  its  hydrogen 
eom^wunilA.  If  thcw  be  dunotcj  by  the  general  fornnilu  ('„lI-.„_^, 
then,  even  when  a  and  ;)  are  betli  large  numbcre,  the  boiling- 
points  of  theee  substunucs  are  reUlivi-ly  low,  and  rise  with  the 
increase  of  both  m  and  ;).  For  carbon  itwlf,  '2n  —  ;j,  and,  on 
account  of  the  extmordinnrr  non-rolatilily  of  this  subetunce,  tlie 
ralue  of  n  mu«t  be  rery  great. 


y/tUNCY  OF  CAR60N. 


»3 


VALEKCY. 

17.  T1i«  fttoniK  of  Bom»  olemcnU  bavo  the  property  of  being 
iinablp  to  combine  with  more  than  nne  atom  of  uny  other  elemttnt. 
The  halogens  on  the  one  )innd,  and  hydrogpn  on 
ih«  other,  yield  only  compounds  of  the  type  11.X, 
in  wliifh  X  stands  for  tli*i  hiilogpn  «tom.  Tlila 
pTopenv  i<;  L-idlinl  moniMHihttcy. 

Of  other  elements,  for  oiamplo  those  of  the 
oxygen  groiiii  (O,  S,  Si\  Te),  one  atom  \i  able  to 
combine  wiili  iwo  monuraleni  nloniR.  Such  ole- 
nicnts  are  therefore  called  divalent. 

The  nnmbor  of  uloms  «f  n  iiionovslont  dement 
which  (Tin  ntiilo  wiih  oiiu  atom  of  miotliur  «IeuiL>i]L 
Lhvrefore  iter^'e  lu a  measure  uf  the  Utter's  valency. 
Thus  nitrogen  coiiihiiies  nitli  three  atoinsuf  hy- 
dru^en.  and  ia  iht^refore  Irivitk'nl.     Hut  the  com- 
]>ouBd   NH,  can  still  unite  with  HCI  to  form  J 
NHjClj  in  which  there  are  five  rHonovalect  iitomii 
att4i(?fai'd  to  one  iiiirogen  iitom^  ^o  tlutt  iiiLrnj^eu 
cmn  vAm  he  jientavaUnt.     Many 
clcmenta  besides  nitrogen  hare 
morc!    than    one  degree   of  va- 
lenuy. 

Carbon  forms  with  mono- 
vulent  elements  (.-unijioiinds  of 
the  type  CX,.  It  in  iherf/ore 
tetravaltHt,   anil   if   is  on   ffiis 

/oMHilatiOH  that  the  wfiair  sitfvr- 

structure  of  organic  ch^nistry 

restn. 

The  compoiiiiJ  CO.  ia  also 
an  inBl»uce  of  liic  tctravalciii:)'  p,o     §  _  Hkatiko    Fio.  9.  -  Fi-ask 
of    eorbon.     In    ciirboii    mun-      Schstaiccesis  as       with  IIk.fi. ux- 
oxide,  CO.  ou  tlio  oilier  l.aiKl.      "''kk  Flask.  tosuKNsuK. 

the  oarlxm  aloiii  must  be  looked  »\»>\i  :w  divalpiit.  at  Iwwt  if  the 
dlTiHlencyof  oxyguti  iit  reUiued.  OlhC'r  compaiintlfl  »ro  well  known  in 
-wliich  eArtwn  rn^y  bn  looked  upna  asdivaleiit,  but  tbeir  number  U 
Ter>'  xuiall  in  comparbeD  with  tboae,  niimb^ring  maDy  thousauds,  in 
yth'toh  carbon  mUKt  be  regardt-d  il»  teiravalenU 


tCMMC  CHEMISTRY. 

LABOBATORY    MITH0D8. 

IS.  Refore  wo  prot**-*!  with  the  <I^(u?riptioQ  o(  the  organic 
compoundK,  it  i.<i  ^ipjiiralile.  to  preTcnt  FO{>etitiou,  to  gire  a  sboit 
ncoount  of  the  mnBt  important  pruceesm  osed  in  their  prepunitioa 
and  inTfttigution. 

ileatifig  Subs(a»e<»  To^flhtr. — Thia  procoss  is  rorj-  oftou  used 
with  tho  object  of  inducing  rvActiou  between  bodies,  su>c«  the 
vol(H>itT  of  rifMctioiig  iiion')u«-«  largt'lj  vith  rise  of  toDipenilnro 
("  Inorgmiir  Cheniuttrir."  13  ami  104).  The  procww  varies  acrord- 
iii£'  to  the  leiDpcratiire  to  which  tbvv  muet  he  heiUixl.  If  thU  is 
ConaiJeniMy  In-low  the  boUing-])oiiit  of  themoiit  volatile compoumJ, 
the;  are  hiu{<)v  mixed  together  iu  a  Uaek  Httvxl  with  a  thermom- 
eter, as  in  Fig.  K  The  fliuth  la  immoriied  in  n  bath  of  liqaid, 
whIlt,  oil,  or  molten  Iwid,  HasK's  alloy  or  other  metal,  etc.,  being 
UMLtl  fur  lluM  purpose.  Should,  however,  the  brjiliiig-point  of  one 
of  the  lubitanvea  be  ruached  or  ovGr.>tt4>ppeiI,  then  the  fla«lc  imut 
be  roiiuwrtcd  with  a  c-ondcnecr,  as  in  Fig.  9.  'flip  invention  of 
liki<  form  of  coudcnaiug-upparatux  is  nfitmlly  attributed  to  LiEBIOt 
iilthou^h  it  was  firet  conrtnictwl  by  Weigel  in  1771.  It  conaisto 
of  n  ^liuw  tithe  n/i,  enclosed  in  a  jacket  of  gliuu  or  metal  i,  through 
which  a  Ktn^iim  of  cold  wul4^ir  can  pHas.  If  the  Hubulance  ha^  a 
high  boiling-{)oiQt,  it  is  anfflcient  to  connect  a  loug  gtau  lulw  to 


Tt9.  10.— thsTILLATlOM   .llTABATPe. 

iha  flask;  tho  air  keeps  this  sufliciently  coo),  so  that  a  tube  of  thia 
kind  is  oilleii  an  air-frmdenser.  The  effect  of  this  condenser  is 
CHRily  understood,  the  boiling  lirpiid  boing  onndt-^nfieil  in  it  and 
drop]iing  hack  again  Into  the  flask.      When  it  is  doommij  to 


DISTILLATION  IN  k'ACUUM, 


'i 


heat  Bnbslwnoea  nbore  their  boiling-pnint«,  ther  aro  pLiced  in  a 
fhk'k-wiilted  giants  tiibo  eeiUed  at  one  end,  which  is  th«n  Kefticd  at 
the  other,  &nd  heuted  in  a  tube  (uraoce  (Fig.  3,  pnge  0). 

19.  JJhliilalioH.—Tor'  this  jmrpoeo  the  apiiarBtufl  flhown  in 
Fig.  10  ia  ueeii.  If,  however,  tho 
Itfjoiil  to  be  di8tini<(l  is  of  euch 
Ik  iiiiicrv  tliikt  it  wuutd  becomo 
ountaiQ iiifttcd  by  the  action  of  its 
TRpoiir  on  th«  cork  or  rubber 
Btoppor  Bhowii  in  tho  figure,  a 
di8til1iug<11»8k  (Fig.  11)  k  sub* 
etituCed  for  the  ordinary  one.  and, 
if  its  oeck  be  sufflciently  long, 
allowa  the  pnbatanc*  to  be  dis- 
tiUed  without  comiag  in  contact 
vith  iho  stopper. 

20.  Many  Bubstances  dBcom- 
po&i'  when  heated  at  th«  onliuary 
prosaire  to  their  boiling- poiutu, 
bot  diittil  unchanged  uudvr  di- 
mintsbcti  pressure,  because  the  boiling-point  in  then  much  lower. 


KlO.   II.  — FnACTIOMATnTA-rl^SE. 


Fl8.  la — DlBTH-LATIOSI   IH  VaCTTOK- 

"T*bo  apporatuB  shown  in  Fig.  12  may  be  used  for  mcuum  di»- 
tUlatioa. 


36 


OKG^WC  CHEMISTRY. 


'i'ho  lif^iiid  o-hich  is  to  be  distilled  in  placed  in  ri.  A  glagit  tnbe 
e,  flmwn  out  to  n  very  fiii(>  p>nint,  dip^  into  the  liquid,  und  n  tlicr- 
inoineti?r  Ik  placed  iimidc  thi8  Cube.  As  soon  a^  the  appamtUH  has 
been  mack  Tacumia  by  tbe  WBttT-pump  w,  a  stream  of  smn])  bub- 
bles of  air  t)8c;apo3  from  the  very  fine  point  of  tlie  tube  e.  This  is 
to  prevent  the  violont  "  bumping"  which  occurs  when  liquids  arc 
l)oiled  uiidor  diminifihed  prossiiro,  cmisod  by  the  audden  and  inter- 
iiiiltent   formntion   of  vapour,   whereby    boiling-ovor    somotimes 


FlO.  13. — FK*mO)*ATI!*G-COLfM!t8. 

Mcan.  or  tho  flaak  is  broken.  The  rccoiTer  I  is  kept  cool  by  a 
atream  of  water  from  c;  m  is  a  mercury  manometer:  a  a  two>Tay 
stop-cock  which  pormirs  access  of  air  to  tho  upparatiis  after  tbi- 
diiitillation,  aiid  at  llic  same  time  serves  to  cut  off  the  codDectiou 
betweeu  the  air-pump  and  the  rest  of  the  apparatus  when  tbe 
pump  "etriketi  harrk  ";  that  is,  when  tho  water  rises  through  tbe 
tube  *  into  the  apparatus. 


FR^CTIOKAL   OSSTILUTION. 


«7 


31.  Tlie  »ep4irntiou  of  a  mixtare  of  Tolatilo  satjetADCve  iti  effected 
\>y  fractional  dietilMion.  If  a  mixtare  of  two  lifjiiidB,  boiliiig  &ay 
at  loo°uiid  at  i:ur,  h  <]iBliUt»tl,  tliit  oiio  tijal  Iwik  at  100"  will 
distil  over  priiici^nilly  at  ihv  1i«ptintug.  and  the  ono  wliidi  boils 
at  130''  at  the  end  vt  ihu  o[K<ratitiii.  If  what  juutsea  over  before 
the  thfnnoint'UT  renchi-a  110'  is  coUcL-teJ  »cpiinit«ly  in  ciiio  frac- 
tion, anil  ttiruilarly  vhttt  \nigsm  over  hetweeu  120"  aiid  VK",  a 
ronxh  scpnrtitiou  has  alren<ly  been  effc^tcil,  vhilc  the  middli) 
fraction  utill  <!oiiaiii(ii  nf  a  mixture.  Tu  iiuike  the  scptinition  ns 
ctTnplctc  :iH  poKsiblc,  the  fraction  100''-110''  is  pnt  back  into  tbo 
fmrtionating- flask  anil  diKlilloJ  over  til)  thn  t Iiermnnietor  renchos 
IIO",  Iho  frac-tiun  llO'-l'^i''"  buug  now  mixed  with  the  residne  in 
iho  frautioiuitiu{:-flMk.  The  dietUlation  ia  then  continned  till  ihe 
thermomftvr  again  stand g  at  IHV.  Another  receiver  is  now  em- 
ployed, ami  t]i4>  dislillation  r^ontinnei!  till  tho  tht^rmomctcr  reaches 
130*.  ^Vhen  tlijg  is  the  rnse.  the  fraotion  ISO^-tSO"  ib  added,  but 
the  receiTer  is  only  changpil  when  the  thermometer  again  iiidicut<a 
120".  The  portion  which  ilistils  after  this  in  collected  sepurati-ly. 
By  repeating  this  pro<:c«i  wvoral  time*,  during  which  it  is  usually 
desimhle  to  collect  the  fraetions  helwcen  narrower  limitd  of  tvm- 
perataro.  and  thus  to  iiu-rcii^o  their  mimber,  it  is  poaeibl©  iu  juauy 
usee  to  effect  an  almost  complete  eepiration. 

Thin  Bepanition  is  greatly  facilitated  by  using  a  fractionaling- 
coltiQin  (Fig,  IH).  which  in  connected  to  the  nt-ck  of  the  boiling- 
Qttnk.  and  haa  the  effect  of  condeneing  the  lenet  volatile  ]iart  of  the 
va)>our.  Thie  Li  attained  by  tncreafiing  the  cooling-surfacrn  hy 
meant)  of  hullw,  or  by  ]»iitl.ing  obst  met  ions,  Huch  &s  platinum 
gniizo  or  glass  Iwads,  in  tho  way  of  the  vapour. 

IS.  A  mixiiiryi  of  liqiiifU  cannot  always  bo  flep&ratod  by  fr&ctional 
dbtilUtinii.  Whetlicr  tbU  is  possible  or  not,  dcpentla  on  tbo  following 
enntideraiitiiiB.  If  two  liquiUs  with  different  vaitour  tenuohH  nro 
misml  to  Htich  a  way  lUat  a  Rmall  quAtilily  of  llio  unc  is  continually 
n'ldi-il  to  the  nllior.  It  t«  often  (ounil  Itint  itiv  vnpnur  (ension  of  ihia 
tnisture.  itte  ic»i)<fnitur<;  ri'maiiiiii^  itio  sutnc,  riBcs  or  fiilt«c»iitinu> 
ally,  lilt  anility,  wlicn  u  great  excewi  of  ilie  secuml  Uquid  Iina  bevn 
adile<l,  lIiD  rapoiir  tension  of  tlio  latter  ia  rnry  nearly  reoi-lied.  Tlils 
Lt  gmphtcally  represonied  by  the  line  AB  m  Pig.  U  The  rnpour 
teoaions  of  tlie  nuxtur«a  all  lio  betwecm  tliOM^nf  the  two  {Him  sub* 
aUnouK.  wliieh  enn^illiiiR  Die  ninxiiiiiiin  H  ittiil  mininnmi  .1  for  tho 
whole  series.     In  aoiua  caaea,  liowcver,  it  baa  twcn  sliowii  tbxL  in  Hit* 


«8 


ORCMMC  CHEMISTRY. 


wn;  A  mixture  n  oblaitMd  wtiose  TApour  tetuion  is  a  maxitDnin 
{f\g.  IS)  or  a  miQimam  (PJi.  19).  It  is  tb«n  inpoenble  lo  effect  mjh 
aratlon  b;^  fnctlooAtiog,  us  ma}*  bn  seen  in  the  tollowing  iraj.  Tb* 
most  TolntilQ  portioa  nf  a  liqaid  idwajs  dUtils  Snt,  and  itt  tho  cose  of 
a  mixture  witJi  a  maximum  vapoar  teuKiou,  this  is  itio  must  rulaiilo 
ponton  o(  an  nrbitrnrr  uizture  of  the  two  liquids.  On  ihb  acooinit 
there  wilt  be  flniUly  oblHinc<l  a  Trnction  luiviiig  tbe  eompoaiUoii  of  lh« 
mixlure  with  maximum  vapour  tvnsiou  ;  which  of  the  tiro  stib«UDcM 
will  be  obtained  in  tbe  iiiiro  Ktnta  will  deiwiid  ii{)on  wbioh  of  tbe» 
WM  pneeat  ia  graator  proportion  in  tbo  origioaJ,  not  in  the  Anal, 
mixture. 

If  there  «xiala  a  uixtars  cf  two  liquids  with  miQimpm  vapoar  ten- 
sion, this  is  llie  iMSt  voUltle  part  of  thellquid,  and  it  will  be  obtained 
as  the  final  residue  after  tliu  diet  illation.  Wliichof  tbe  two  sabslauoos 
oaa  be  obtained  pore  from  tbe  mixture  will  sgaio  depead,  as  bvfocs, 


rts.  i«. 


Fig.  15. 


Pio.  16. 


OD  the  ratio  of  the  quaatities  of  the  two  liquids  vbJcb  were  originaDy 
present. 

Tbe  aoporation  of  a  mixture  of  liquids  hy  fractiouatioa  is  also  ii»> 
possible  when  the  boiling-fwtala  of  its  coiulitiiuitts  are  close  togi'tber. 
beoause  the  essential  cbaraelerislic  of  the  wholi-  method  consists  ia 
the  unequal  volatiliiy  of  tbe  portions  of  which  the  mixture  is  madaupy 
In  conset^uetice  of  whiob  one  sulwlAnco  di»lils  oTi>r  before  the  olhfr. 
If,  howvvvT,  the  substanoea  bare  about  iho  same  boiling-point,  then 
thcjr  both  attain  to  a  vapour  tension  of  one  atmosphere  at  almost  tbe 
same  temperature,  being,  in  other  words,  almost  eqaally  volatile.  It 
is  therefore  impossible  under  these  conditions  to  apply  the  method 
tnoceasfullr. 

23.  ^feam  Distillation. — In  tlw  iirepanttinn  of  many  organic 
nibstancee  a  cmdo  roaction-prodnct  is  oft«n  obtainc<]  containing' 
tarry  or  pitch-like  iiiattt-T  nlong  wilili  the  rKtiiiirwl  (rumpounrl.  In 
order  to  free  the  sub&tance  from  this,  neo  is  often  very  advaa- 


ST£^M  DISTtLl^TlON. 


39 


Idy  mado  oi  the  property  possessed  by  manj  sobstniirefl  of 
distilling  i»  n  carrcnt  of  Hteani,  l!i«  turry  matturs  rptnuJDiug 
behind.  Fig.  l*  bIiows  the  nietlnxJ  liv  which  such  r  distilUtion 
is  ciirriud  out. 

Water  is  boilotl  iu  tbo  can  a,  'ftliich  is  fitteil  with  &  delivery 
tube  (*  Dud  A  safety  tnbo  b,  the  evulved  at«QU)  b«>iug  p«Bs«d  iuio  the 


Fra.  IT.— Steam  DisTrt-LATioN. 

bottom  of  the  distill ing-ilask  d.  Jf  the  diHtillntion  Is  intomiptedf 
cooliii^  CBUfioa  dimiQi«h<td  presMuro  jn  a,  uir  Itcing  then  »h]e  to 
enter  the  tnhe  b.  It  b  wvro  not  u»ed,  the  Uqtild  in  d  would  flow 
book  into  it,  owing  to  tho  fnll  in  tho  etotiin  prcfisiiiv. 

Stf>iim  diiitillHtion  is  nl-in  of  Kervioo  in  ^cpninting  oompoLindSf 
somo  of  whirh  an?  Yob-tile  with  eteiuii  and  othcTs  not.  Iu  ihe 
case  of  substances  vrhich  are  insoluble  in  wat«r,  the  distillate  is  a, 
milky  liqnid,  bm-aiiso  tho  wutt-r  which  has  dietillod  over  in  mixed 

with  fine,  oily  drc-ps,  thpre  being  at  tho  «ini0  time  au  oily  layer 

aboTo  or  beneath  tho  wator. 

"Wh^n  distiHing  wilh  stoftin,  tb*  |)ressur«»f  lUo  miiluro  of  v^iwun 
must  be  cqiiitl  to  iliat  of  ilie  barometer,  niiice  ibv  lltjiikl  is  boiling. 
Tl)«  boiling-poinl  tnuat  bo  loner  thnn  that  of  thu  low-pr-lmiling  of  th» 
two  5 II  tut  I  an  CCS  under  ordiijary  iiressun.-.  iM-cnuflrt  the  partiHl  preaiare 
is  Tjeceasarilr  ftmnllnr  than  llic  tuiiil  one,  whioli  is  ei\n!i\  to  the  Atiao«> 
pfa«rlc  pressure'.     TLi;  eamo  rcanlt  U  Ibercforo  olHairied  an  wtieti  dis* 


30 


ORCANtC  CHEMISTRY. 


tilllnic  nnder  cllmlnislied  prmturv.  vix.,  tli«  TolittillMtiun  of  tb«  %\io- 
elstiGoat  B  touponituro  low«r  tban  its  boUiug-point  under  onlinwf 
prtesuro. 

Whether  a  substAuce  dblils  quickly  ur  slowly  writb  tteuiu,  depeuds 
on  lu  partial  ]trnitj>un<  and  on  its  vupour  d«n*)ty,  togetaer  nith  tlio 
vaIu«s  v(  thv^c  physiciil  coustaata  for  water.  [[  tho  prcuurvd  are  p, 
nnd  pt,  xnd  the  vnpour  deusUieft  (/>  mid  d,,  the  qtuiulili«s  which 
distil  over  &iuiull*iieoiuly  are  ptd\  (aubalaiice),  iiud  ptd^  (water),  If 
the  ratio  p^d^  :  ptiU  U  largo,  thosubttan&e  dl»tilit  over  with  a  araall 
quantity  of  vatcr,  the  dislillnlion  Wing  quickly  carriix!  out ;  tlie  re- 
verse Uiiim  pliici!  wheu  ihH  ratio  p.iii :  p^il*  is  small. 

24.  Separation  nf  Tim  />/imisrifjle  AiV/Mirfji.— A  KeparntilUf- 
fuiinel  is  uwil  for  this  piirptMu  (Fig.  ]S);  the  nietli<Mi  tif  using 
it  inuy  be  inferrcJ  from  t}ic  ilruwinjr  without  further 
cxpluiuttioii.  It  ix  uleo  rtuployiHl  for  i\ie  exi rari n^n 
of  tH|UCuu8  solutions.  Tbi?  iii|ttcoui  soliitiou  of  a  sub- 
8taiirQ  »ohibIe  in  n  volatile  liquid  nut  miscilde  witli 
*'iitpr,  Btich  HB  rlftfi\.  pftrniftntt-fthfir,  chlaroform, 
airhon  bisuiplndf,  ia  irHnfifcrri-d  to  ii  si>|)aratiiig- 
fuiiiirl;  ether,  if  tlmtia  the  solvent  iit-lecrt«d,  iiiudilud, 
ami  uftcr  tht  ttioiith  i)f  llie  fiimii'l  liim  bwii  cIommI 
by  M  glaB»  stdppor,  tlic  two  li(|iiid»  ore  luixvd  toKctlifr 
by  vigorous  abnking,  whon  tho  auhjttnnoe  whirb  i* 
di880lvi>d  in  water  pacsoi;  piirtly  into  the  elbor.  'I'lio 
ethereal  unlntion  in  allowed  tn  rise  to  thf>  top,  nnd 
8«paraled  from  the  vatcr  by  opniiin;  tlic  stop-ciock 

»ATiKO-ncM- *'*■*'''  '■*''"**^*'  ^f  *''"  Btoppor.     The  watur  whiL-li  haa 
SBL.  die«ohv!d  in  tho  ctbordunTif;thc£lmkti:ig,  ie  rc-morod 

by  chloride  of  calcium,  or  wmo  other  drTp-ing-agcnt,  niid.  finnlly  the 
eth(>r  ia  distilled  ofif.  Tho  extraction  is  coniplotoii  qiiioklr  «'h«n 
tho  dissolved  BuUittADce  is  only  slightly  eohible  in  watt-r,  and  (•mdly 
ftolublv  hi  I'ther:  it  is  then  poHsible  to  nlmost  wholly  exiiaoet  the 
aqueous  »olutiun  by  ivpealin^  the  opurtition  a  few  times  with  fresh 
ether.  OtJiwrwise,  the  shaking  miut  be  repeatedly  earned  oat, 
and  even  then  the  extraction  is  imperfect, 

Wlicn  two  iiDinisctblcBolvfltit^  arc  simiiltam^oDsly  in  contact  with 
a  Rnbilance  vrbivti  is  soluble  in  Imth,  tlii>  lattirr  dislribuieK  itself  in 
flitoli  a  way  tliat  llii:  ratio  of  the  ooiicoal rations  reached  in  both 
Mlvenls  Is  coiitttant  (law  of  RKRTHDjrr).  If  n  <jiiB.iitity  J',  of  th« 
substanca  is  disat>lTcd  in  a  qiiaulity  I  at  tbo  first  soivcal  iwaier),  and 
tills  soinlion  is  s)ialceu  up  with  ii  quautity  m  of  the  second  solrent 


HLTR^TION. 


3> 


<eitt«r).  xhtfw  will  then  miiNiti  »  qiuDtitj  X.  in  the  lint  soluiioii.  to 
thiit  .r.  —  J',  liM  jhukU  mlo  Ihe  »9Coud  8olv«iit. 

The  viiluti  of  llio  quBiilJty  A'>  !>.  in  a(!oortl>Doe  with  tbe  nbovo  Uv, 
given  by  tbo  vquatiou 

-r.  =  .r.   ^' 


m  + 


^i* 


A7     \. 


for  t'  luid  ^'  iiro  the  two  concoturatiiina  aftirr  tlic  tolvsotx 

I  Nt 

bavo  beoii  ftliiUcvn  iij),  nnil  JT  is  ibe  number  oxpKutng  t)i«  eomiftnl 
rmtio,  orthecvc^Mmf  Q^f/MrJbuJ^ti  (.Qennaii,  Ttilunu^toiffitiefa}. 

A  Bwond  extraottoii  with  the  ftnino  quAiiLity  m  of  tfaa  seeond 
aolraiit  Rivn 

.r.      ^  J.  -  jr. 

or,  aubMltntJng  ih«  vnln*  of  A',  fmoi  ih«  flnt  «qtiiitl»n, 

-■=-'--(^,)' 

and  (oi  llta  rdb  rstTKction, 

TtiuH  .v.,  xhti  qimaliiy  rouixinltig  in  the  flnt  solvent  (walerX 
dlrolaiahcs  m  n  incrvnavs,  ftad  u  m  mid  A'  are  reipectivoly  KKHler 
ficd    les.      ComplfU    cii.rACllon    is    imposaible.   becniiNo    »ltbougb 

^-^,1  can  approach  Mro  very  closely, 

it  CiUi  a«ver  Ltecomv  eijuAl  lo  tl. 

It  coil  bo  further  nUowh  from  this  equti- 
tioD  by  tbv  iisu  of  lltu  ililTn-oiitial  ciilciilue 
that  with  II  givL'H  qilHiitily  or  Oio  i^rcoiLd 
solvent  (ether)  n  more  cuiupleii^  sepiimtion 
Ifl  utTcclod  by  extritctiiif;  frequently  with 
Hniall  (|iiuntili(»  than  by  uftin^  Urgt'r  qiiau- 
tiUpK  M  uorr««[>on<] in]{ly  fewer  number  of 

Separation  of  HolUh  anil  Liqmda, — 
Tti*  is  effected  by  filiration.  vhir:Ii  can 
b«  materially  at^releniit"!  u\  fitting  the 
ftinni?!,  by  inaiiis  of  h  rubhtT  9(ojn)er,  iii 
SL  fbtok  a  (Fig.  19).  which  h  coiiiiufiiHl 
lUrouj^h  //  lo  a  watiT  nir-puuip.  To  iirt-vont  niptiire  of  the  poinc 
oi  thd  filter- {Ml per,  it  miiat  then  be  suiiportcd  by  a  hollow  platinum 
con«»  A 


l»  —  J'll-TJIRINO 


3» 


OKGAStC  CHEMISTRY. 


25.  SfpamtioH  of  Solitfji/rvm  one  Another. — This  uaiiaUy  de- 
pemla  nu  rliffi-renec  £n  soluliility.  If  there  nro  two  substauova,  one 
Kilti'ble  nnd  the  other  nuohible,  the  opemtion  is  very  gimjile.  It 
both  i!uhetnin-C8  arc  Bi>luhlc.  tho  nifthoii  of  fracfionai  er^tttdlita- 
tiou  must  he  used.  Thv  mixture  is  diBsolrticI  in  the  leiut  pu»iblo 
(quantity  of  a  hoiling  ]ix|iiUI,  mid  s)lou-«d  to  fool,  Thp  more 
iiiftoliitilo  ^uhntttiice  crvHtiitliKea  oiit  first.  The  nnother-liqtior  in 
poured  off  before  crvfeUiIa  of  tho  second  body  be^In  lo  sepanite, 
nnd  tlie  Bocond  compouni:!  is  crretalhsi-d  cither  by  further  roalinje 
or  by  conccutrftting  the  li<iui<l  by  t'Vdporation.  Oii  n-pi^tiug  thvae 
Qporatioiiii  several  tiineA,  the  Buhstances  are  obtained  s^pflmted 
from  ontt  iiuother.  The  Kepuratioii  of  substanciis  in  thia  way  ie 
enmetimBB  very  difficult,  even  if  thero  is  h  very  great  difference  of 
■ohihiltty  between  tho  pure  compuuDdn,  boniiiac  tho  soluhiHty  of 
one  mibetttncw  may  be  very  considerably  modified  by  the  presence 
of  anothiT.  Wnter,  alcotiol,  ether,  ;;laciul  acetic  acid,  bcnzi-uc, 
and  othpr  subalancoa  art*  used  iia  solvents. 

26.  It  is  seen  from  the  foregoing  how  substanees  may  bo 
obtained  in  the  pure  slate:  aolid  iubstances  are  usually  purified  by 

cryaliLlliEation^  ami  liquids  by  distillation.  An  in- 
ilicalioH  of  purity  is  that  the  physical  constants  re* 
main  unchanged  after  the  sohstanca  has  been  purified 
anow.  Although  every  ph^xiL-al  eonstaiit  onnid  ser\'0 
this  purpose,  the  viddn^'point  ami  the  fmiling' 
jmittt  art!  tbost-  most  used,  btcuusc  they  are  easily 
dcteniiinud.  and  eli^ht  impiiritius  cxcri'ide  ii  very 
material  influence  upon  theuL.  They  nrv  al»o  often 
a  means  of  identifying  snh.'rtancGS.  .Should  a  com- 
pound, supposed  to  be  one  already  known,  liavo  i:)oon 
obtained  by  iuaie  p^o^^ess,  it  is  strong  endenre  in 
favour  of  the  supposition  if  the  melting-point  and 
butliiig-poiut  of  thu  eubtitauee  coincide  with  those  of 
the  compound  with  ^vhich  it  u  supposed  lu  bi-  iJen- 
Fto  SO  —nu- *'*"'■  f*»tftrminalionB  of  melting-points  nnd  boiling- 
TKiiaiNATioN  points  affl  for  this  mason  very  often  airried  out. 

To  (letermiue  the  viplfiuff-poiiit,  tiie  siihstiinno  i« 
placed  in  u  narrow  thin-walled  small  tube  ^eslerl  at 
one  end  (Fig.  20),  this  tube  ia  alUichrd  to  u  thennometcr  /.  (he 
bulb  of  which  dips  into  u  liquid  of  high  builiog-pomt,  such  as  con- 


U 


OrTHE.XIHLT- 
ISO- FOIST. 


sPBcI^tc  c/wwrr. 


33 


Ited  mlplinric  acid  or  liquid  jtaraffln  (38).  iho  visooaity  o( 
^Sfidl  caiiaes  the  fimull  tube  t-o  adhere  to  the  thermometer.  The 
tube  ale,  in  vhich  the  hulb  of  tho  thermomclor  amd  tbo  littlo  labe 
arc  idacfd.itt  loosely  ttxcd  in  a  small  roiiQd  glnas  flask  ar/c,  cntitnin* 
ing  the  Hame  liquid  at:  the  tube  ak.  When  ade  \s.  heated,  the  con- 
teut«  ot  the  tube  ale  aro  waniieil  imiforiuly,  and  the  moment  of 
fusion  of  the  Huht^tunce.  at  whii^h  the  thermometer  is  road,  cnn  he 
Twy  accunitclj  ohsejred. 

The  boilivff-pinnl  is  determined  by  heating  the  liquid  to  bniU 
in<;  in  a  fractionntinif-fiii^k  with  a  iiigli  sido  tube.  Short  thcr- 
mometerg  are  need,  30  that  the  whole  of  the  mercury  column  is 
snrrunnded  by  the  v»pour  of  the  boiling  liquid.  In  order  to 
avoid  iii<;onT«nifintIr  .tmall  gradual  ions,  ihpse  therincmoters  BTOr 
coniitnictcd  so  rliat  they  can  only  ho  employed  fora  comparatively 
aroall  range  of  iL-mperatuTc,  six  or  seven  different  inatnimcnta 
being  used  for  temperatures  between  0''  and  360°. 

S7.  fiometinm  ntli«r  ptiytiical  confttanta  beaides  the  meltlng-polowi 
mill  boiliiig-pnjnta  are  dotdrmiiied  in  the  inroctigatiou  nt  nrf^n'tt  eoui-i 
iwuuds.  I.  Tim  tjMi/U:  ijrmnln  can  \»  de- 
tormioed  with  tlio  pyknnmrUr,  the  moitt 
useful  form  of  tvhicli  is  eliown  in  Pig.  31. 
It  oonsists  of  two  thiok-walli^d  cafiillBrieH 
alt  aud  cc/|  whtuh  termiiiale  in  a  widor 
tube  he.  The  pans  aa  and  dd  are  tur- 
nisbed  with  n  itiilliiiivtrt;  »CAle  The  cajia- 
cilT'  of  Ibo  apparatus  it  ftrst  dPierniinod. 
as  well  as  of  the  space  bolwoco  two  divi- 
sions, by  fllliog  it  several  limes  up  to 
different  diTisiona  wilh  nater  of  knonn 
temparaiure,   and    tlion   weigbing.      The 

liquid  wtioec  siwciflu  grnvit;  is  to  b«  dotonsiiied  b  then  placed  in 
the  apiArnluK.  wtircli  is  neighed  ;tfrer  tliu  positions  nf  the  menisci 
ia  the  cnpillaries  have  b«vu  obisorvcd:  from  this  tbe  required  number 
may  be  calculated. 

2.  Tbe  rotation  of  the  plane  of  polaHiaUon  is  auolher  oottatAiit  of 
IraimrlanM). 

t^mo  subfllanccs,  sncli  as  tnrpMitino,  a  solution  of   sugar,  ete,, 
lutre  tbe  projierty  of  jntaUng  the  plniie  of  a  rn;  nf  pularized  ligbtj 
which  is  passing  through   Ilium  out  of  iU  original   position.     This 
pbeoooienon   is  called   the  rotation   qf  the  plant  q/  pulotisntttm. 
aud  substances  whieh   poeseu   this  property   are  said   l»  be  vi'li 
aiilft  active,    f^larimelerx  tmve  beeu  oonstnicUHt  for  niunsiirtTig  the 


FlO.   SI. — I'VKNOMRTKK. 


34 


OkCANtC  CHEMISTRY. 


»af^K  through  which  tbe  pikne  of  ix>l&rir,at inn  han  l>een  mlaivtl  l»y 
nn  ojiiicitlly  active  scibiitBnci! ;  of  these  I.ArREJCr's  iFif;.  22)  m  oiifi 
of  tilt  XwtX,  known.  TItr  vfllow  Kniliiiiii  li^ht  nf  (be  burner  7T  is 
poliiriuid  in  the  \Mri  of  Uio  »|ijj)intliiK  tnnrkeil  BD.  nud  llion  passes 
throui;li  n  ttibe  placed  in  ihe  channel  /•,  llie  leogth  »f  which  is  acou- 
rait'ly  Icnown  (200-500  mm.),  t'otuaininj  Kte  litjuid  or  aoluiion  whoMi 
optical  aciiviiy  in  to  Ui  itcleriiilmMl;  llii;  prtrl.  OU  nt  tlm  ajijiatnlus 
terves  lA  ti)i>ii&iiru  (ho  ralaltnn  nf  ihti  pliiiio  »r  [lohirltaiion. 

Tliu  cxicut  \'>  which  tho  plane  of  polHri%niioii  is  r«tatei3  is  propor- 
ttoDftt  to  the  length  of  the  tuba,  a»(]  is  exivroBsuil  iu  diffeKUE  ways. 
Tba  TOtAtioa  of  a  subcianco  is  czprasMil,  f>>r  L-xample,  iu  terms  of  the 


I  » 


■:  1  -  r(ii..v  f 


effect  producc^l  \>j  a  giwii  l«iigth  of  the  tuba  nbovo  r«ferro(J  to;  ihi» 
is  the  angle  which  is  read  off  directly  from  ihe  iiistnimeul,  II  U 
usually  denoted  hy  a.  By  cniivpinion,  the  njivri/ir  rulMorg  jtower 
U  defined  as  Itiv  quolii^tit  obtaineil  hy  dividing  't  by  the  product  of 
ttae  lODgth  of  tho  (ulio  into  the  Rpecitic  gratity  of  the  htinid.  This 
value  1»  donotod  by  [a],  bd  thai 


[a]  = 


U 


where  I  U  tlie  length  of  the  tube,  and  d  ]s  ibe  specific  (Cravitjr  of  lb* 
liqniii.  I'ndor  these  couditians  [«]  ciprcisim  the  rotatory  jM^ver  »(  a 
Bubstaiiee[Xirunit  Icnglliof  the  tnhull  deuiiiii'll'u),  and  rni-iinit  W«tght 
of  tbo  Hubstance  divided  into  iIk  unit  vf  voLuiac. 

TIte  pxu-nt  of  ihe  rotitiion  is  de(iendi<nt  on  tbo  coloar  of  the  U|fhl. 
Id  niany  cases  the  muaaur«ut«nt  is  carried  out  with  sodium   light. 


CLASSIFICATION  OF  ORGANIC  CHEMISTRY.  35 

wliicL  gives  a  yellow  line  in  the  spectroscope,  denoted  by  D.  This  is 
expressed  by  the  symbol  [ajn. 

When  the  rotatory  power  ol  a  substance  is  small,  or  when,  on 
accoDQt  of  its  slight  solubility,  it  can  only  be  obtained  in  dilute  solu- 
tion, the  rotation  can  be  increased  in  many  cases  by  adding  a  solu- 
tion of  boracic  ncid,  molybdic  acid,  uranium  salts,  etc.  The  cause  of 
this  phenomenon  is  not  fully  understood. 

It  is  often  important  to  dclermiae  other  constants,  such  as  the 
index  of  re/raction,  the  molecular  electric  coiiductivity,  and  the  heat 
lif  combustion. 

CLASSIFICATION   OF   OROANIC    CHEHISTRY. 

28.  It  is  UBunl  to  arrange  tho  extraordinnrily  great  number  of 
organic  compounds  in  two  main  divisions.  One  of  these  includes 
ih.Q  fatty  or  alijikatic  compounds,  and  the  other  the  aromatic  com- 
pounds. The  first  of  these  owes  its  name  to  the  fact  that  the 
animal  and  vegetable  fats  belong  to  it;  the  second,  to  its  containing 
many  compounds,  among  the  first  to  be  discovered  in  this  division, 
characterized  by  an.  agreeable  smell  or  aroma. 

The  fatty  compounds  and  the  aromatic  compounds  are  re- 
garded as  being  derived  from  methane,  CH,,  and  benzene,  Cgll^, 
or  compounds  related  to  it,  respectively. 

It  will  be  shown  later  that  there  are  important  differences 
between  the  general  properties  of  these  two  classes  of  compounds. 


FIRST  PART. 
THE    FATTY    COMPOUNDS. 

SATU&ATED  HTBROCAItBOirB. 

29.  The  fatty  compoundB  arc  defined  iu  28  aa  those  which  may 
he  regarded  as  derived  from  methtme,  CII,.  It  is  therefore  advie- 
ahle  to  begin  tlie  study  of  tliese  coniponnils  with  this  hydrocarbon. 

Methane  occurs  in  nature  in  the  gaet-s  oYolve<l  from  volcanoea; 
it  escapes  in  coal-mines  during  the  working  of  the  coal-seams,  and 
is  called  fire-damp  by  tlie  miners.  It  ia  also  called  marsh  gas, 
because  it  is  preaent  in  the  guaes,  duo  to  decay  of  vegetable  matter, 
which  rise  out  of  marshes.  It  is  an  important  constituent  of  coal- 
gas,  in  which  it  is  present  to  the  extent  of  30-40,^. 

It  can  be  prepared  in  diiferent  ways. 

1.  (rt)  By  Bertiielot's  syntheeis.  A  mixture  of.  H,S  and  CS, 
ia  led  over  red-hot  copper  contained  in  a  tube,  when  the  following 
reaction  occurs: 

2II,S  +  CS,  -f  4Cu  =  4Cu.S  +  CH,. 

{h)  By  Sabatiee  and  Se.vderens'  synthesis.  When  a  mixture 
of  hydrogen  and  carbon  monoxide  is  passed  over'  reduced  nickel 
at  20O°-25O°,  methane  is  formed : 

CO  +  .^11,  =  CII,  +  11,0. 
The  nickel  undergoes  no  apparent  change,  and  can  be  used  re- 
jH-ntedly.     At  a  temperature  of  aaO'-^JOO",  carbon  dioxide  reacts 
i<imilurly  with  hydrogen  in  presence  of  finely-divided  nickel: 

CO, +  411,  =  C'ir,  +  2ir,o. 

Reduced  cobalt  has  a  similar  action,  but  requires  a  somewhat 
higher  tomjierature.  Since  CS,,  H,S,  CO,  and  CO,  can  be  obtained 
l)y  direct  synthesis  from  their  elements,  these  reactions  furnish 
methods  of  preparing  methane  aynthetically. 

36 


SATURATED  HYDROCARBONS.  37 

2.  By  acting  on   the   compound    CH,I,  methyl  iodide,  with 
nabcent  hydrogen : 

CHJ  +  2H  =  HI  +  CH,. 

Nascent  liydrogen  can  be  obtained  in  different  naye:  from  Bodium 
amalgam  and  water,  from  zinc  and  bydroctiloric  acid,  or  by  bringing 
zinc  which  has  been  immerBed  in  a  dilute  solution  of  copper  Buiphate, 
to  coat  it  with  a  layer  of  copiwr,  into  contact  with  water.  By  tlie  last 
method,  which  was  dincovercd  by  Gladstone  and  Tribe,  hydrogen  is 
evolved  at  the  ordinary  temperaturo  in  a  form  in  which  it  is  able  to 
convert  methyl  iodide  into  methane. 

Methyl  iodide  can  also  be  reduced  to  methane  by  hydriodio 
acid: 

CH,I  +  HI  =  CH,  +  I,. 
To  effect  this  a  concentrated  aqueous  solution  of  hydriodic  acid 
is  heated  with  methyl  iodide. 

The  iodide  formed  is  converted  back  again  into  HI  by  the  addition 
of  amorphous  phosphorus.    The  hydriodic  acid  is  regenerated  : 

P  +  I.  +  3H,0  =  H^PO,  +  3HI ; 
and  is  available  to  effect  further  reduction. 

3.  By  decomnpsing  zinc-methyl,  ZuC,H,  (82),  with  water: 

zS^Sw-^^^fi  =  Zn(On),  +  2CH,. 

4.  By  heating  sodium  acetate  with  barium  hydrate: 

CH.COONa  +  ba*OH  =  baNaCO,  +  CH,. 
30.  Physical  and  Chemical  Properties. — Methane  is  an  odonr-       f  fT 
less  and  colourless  gas  of  sp.  gr.  0-559  (air  =  1),  lique^ng  at  11° """^Tv'i 
and  180  atmospheres.    It  boiU  at  —  102°,  ahd  solidifies  at  —  186°. 
It  is  only  slightly  soluble  in  water,  but  more  bo  in  alcohol.     It  is 
decomposed  intd  carbon  and  hydrogen  by  the  sparks  of  an  induc- 
tion coil,  or  in  the  electric  arc.     Oxidizing-substauces,  such  as 
nitric  and  chromic  acids,  do  not  attack  it,  or  only  very  slightly, 
while  concentrated  sulphuric   acid   and  strong  alkalis  hare  no 
action  upon  it.     It  bums  with  an  almost  non-luminoua  fiame. 
When  mixed  with  air  or  oxygen  it  forms  a  violently  explosive 
mixtnre,  the  reaction  being  in  accordance  with  the  equation 

\  CH,  +  20,  =  CO,  +  2H,0. 

This  Bo-called  "  fire-damp  "ia  the  cause  of  the  explosions  which 

*ba  =  iBa. 


JS 


;^A;C  CffhMlSTRY. 


StimcLimeK  cxhtiit  in  mat  niiiieR.      {!lilorim>  nrid  brnrniiip  rcnnt  irirh 
mclbaiip,    tlif  hrdrogen  atoms  of  the  latter  Iwing   rpplactxl 
liulogcn  utunis,  and  u  huioid  arid  formnd : 

CH,+  2G1  -  CllJL'l  -f  IK'I.  ,  .J 

The  rcplnccmcnt  of  one  nt^m  bv  nnothcr  is  callwl  fitmhtutian. 
If  chlnriiin  tir  bmmine  in  prdsmit  in  ejcrpsg,  thfi  tiiial  prfxhiot  ia 
CCl,  orCBr,.  " 

31.  Thero  prints  n  RRrics*  of  hjdi*orarhnns,  the  general  rheniit* 
jinijierlieH  uf  whudi  »rc  idi'ntioJ  with  Ihost;  nf  nietliitne.  KxampU-H 
c»f  thcHH  compounds  are  etkam  C!,II,,  prapiine  *\U,,  butane  C,I[,„, 
frntfu'ie  i'j,H„.  Jifxaif  t',U„(  i'tc,  jmitair'utcunlinte  C^II,.,  and 
hexttcoHUtht  (^'„n,j,.  These  formiilie  «m  be  mimnied  up  in  the 
gon«rftl  exproasion  C„H^^, ;  for  metliaue,  »  =  1.  Those  liyriro- 
cartiuus  i^an  ht>  pri'parL'd  hy  the  iiiothodH  dM^^urilxtd  in  3.  3.  jiiit]  4. 
It  should  bu  obsiTvwd.  liowt-vtr,  tluiL  bj-  monng  of  the  zinc  com- 
pouriila  only  the  lower  tncinb«r)i,  tho^c  (.■outiiitiiug  n  omall  iitim- 
ber  of  carlioii  Htom^,  arc  obtuii)«d,  bi-cau8c  the  higher  ziuc  deriva- 
tJTcs  »ro  not  known.  The  hydrocarbons  C„H,„.,  rceeinWeniethatio 
in  ihuir  |«iwer  iif  resiBtinjf  oxidation,  and  »re  utnieted  on  by  coti- 
epniratwl  »utp)iiirio  acid,  while  h»logeiifl  n-act  with  lliem  with 
Mibstitultaii  of  hydrogen  and  formatiun  of  compound*  C„Ii^,,Cl, 
(^H.„C1,.  etc. 

In  addition  to  i\w  iiK-thodii  inentione<l  nbovo,  tho  liig'hpr 
kydrocarbone  mny  be  obtained  by  buildjn;;  tip  from  the  lower  once. 
For  example,  ethane  cnn  b«  obtained  from  niethiuic  by  rpplaring 
a  hydrogen  atom  in  the  latter  )iy  halugeti,  iind  then  tmutiug  the 
hiilogen  ronipound  thna  obtained  with  Hoditim: 

aCH,l  -^»^=  C,H,+  2Niir. 
Propsuo  cuii  bo  prepared  iu  uccordimco  with  tbo  ioUowing  equa- 
tion: 

CH,I  +  C.nj  +  Kn,  =  C,H,  +  2>i«I; 
and,  in  general.  ('„1I,il.,  >s  obtained  by  the  KCtion  of  sodium  tii>OD 

[n  this  mictioii  <Mlt.>  U  foniifd  from  2C«Htt,  and  CtHi  from 
SC'DiI.  the  result  being  Uint  three  bjdrocitrbona  arc  forniod.  Tbia  is 
alnaijE  the  case  in  synth^fiee  uC  ibis  hind. 

Since  metlmtie  can  be  prcjmu'd  eyiitheticallyi  it  is  ■ovidcntly 
{>oasible  to  synthesize  each  hydrocarboD  of  the  fortutiU  C„I1,b.^ 


rURMTED  HYDHOC^HRONS. 


$9 


58.  yo»tt»eJatHre. — Tbo  hyiirouitrboiw  C„H^„  are  .  Mn'ayB 
denoted  by  the  termination  "aii»."  The  firet  lour  m«ml»erB, 
methane,  ethnDc,  propane,  and  butane.  h»?e  special  iiarnea;  the 
others  are  denoted  hy  the  Greek  or  Ijatin  numeral  correspoudiiif; 
V>  the  numWr  of  carbou  atoms.  Thus  *^JI,^  ia  called  octant; 
C„T1^  ihtiecatlt,  C„ll„  Itentrmwiitane,  etc. 

ll  will  often  l>u  neceeKury  to  consider  groups  of  atoniE  whii^h 
cuQiiot  be  obtained  iu  the  Jrett  iitiite,  but  which  are  derived  fium 
the  hj-dr0(*«rb(pu»  C^H^.^  hy  removnl  of  a  hydrogen  atom,  Ttieso 
groupM  have  the  j[i*iutm1  formulii  (.'„It,„.,,  and  are  n«ially  t-alled 
aik'ifl-groups;  Ihey  arc  denoted  individually  by  changing  the 
termination  "auo"  of  tlio  corrcapotiding  hrdrooarboa  into  "yh" 
In  this  way,  CH,  is  c-alled  meihyt,  C,II(  ethyl,  C,H,  proptfl,  C,H, 
but'ih  i',tiij;itloilectfl,  etc. 

The  hydrocuirhoiia  C'„n,„,,  hare  the  general  name  of  «ufurnted 
hydrcmrhoiS,  brM-ansc  they  are  saturated  with  hydrogen:  that  iti, 
are  unable  to  take  up  any  more  liydrogen  atoms  into  the  molecule. 
Tbey  arc  also  oulled  para^uit,  hecauou  paraffin-wax  con^iBts  of  a 
niixtiire  of  the  higher  mcinbere;  the  word  jmritfliii  i«  derived  from 
partitH  ttffiiiu,  indiotting  that  tbi«  «iib«tance  h  but  slightly  acted 
opon  by  cheitiical  reagents. 

83.  OccHrreiice  in  -Vtr/Kri-.— The  hydrtiearboiis  C„II,„,,  occur 
in  uatlire  in  enormous  (iiiHi)litie;:«.  Cnide  j:Vmeric»n  petroleum 
conslaU  of  a  mixture  of  a  great  number  of  these  compounds,  from 
the  lowoet  to  the  highest  meniJ)ora  of  the  neriea.  Three  prinoiiwd 
produ'-ta  are  obtjiiiii'd  from  this  ]>c<trolc>uin  by  fruetional  ilititillu- 
don,  aft4>r  treatment  with  aeida  and  alkalis  to  free  it  Jroui  sul)- 
rtanre*  which  are  not  hydrocarbons  ol  the  formula  C,,!!,,,,^.  The 
Dost  luhitilo  portion  18  culled  peiroi«nm- ether,  Acmifur,  nap/it/Hi,  or 
Hjfrvin;  it  diBtils  bt-tweeu  40'  and  ISO'"",  and  coritaioa  lower  nicm- 
bcn,  chiefly  C^U„-  t',Mw.  «nd  C,H„.  It  is  extensively  employed 
U  a  solrcnt  for  futit,  oiln,  and  resinii,  and  ia  also  afiplied  to  the 
removal  of  etainB  from  elothing  ("  Dry-eleaning  prooecs"). 

Tlie  portion  whieh  distilfl  at  ^^0^-^(K)''  is  onlinary ^rfroiftim, 
■od  ta  used  on  a  large  m.-alc  for  lighting  and  cooking. 

Tlifl  dai)((«r  involved  in  lu  use  is  by  no  means  small.  M-fiOrf  of  ac- 
cidcnts  by  firv  boing  ntlributAbl«  to  tlii«  tuurce.  TUe  fact  that  fires  are 
odeu  cauaud  by  Dieovorliirniiig  of  fietrnleum  iNinpsiK  Traceable  loltie 
pKftenc«  in  the  petrol«aiu  of  a  part  of  the  more  valnilk  prodtKls, 


: 


'4e 


ORCMttIC  CHEMISTRY. 


vcbo««  vapour  prottucea  *t)  inflamtoable  mixture  with  »ir.  If  a  Iakip 
is  QDcil  with  petroleum  fram  which  the  more  yoUtlle  portions  tiHve 
)>o«a  rftmoved  bv  onnfal  rmcuoniitioTi,  upMiting  exiinguinhM  It. 
Petroleum  of  this  kind  is  found  In  comuerco  iiiider  the  iiftiu«  of 
kif^sate  or  t'ffinfft  petr-tltfnm. 

For  the  purpose  of  nscortairttng  vhether  a  aanipte  of  petroleum 
contains)  these  mon  rolatild  produt^tx,  its  jtaah-paint  is  detcniiin«d 
"hy  heating  it  kIowIjt  in  »  specially  coiistrucLed  nfiparatua,  dcTisad  by 
Sir  FnKDiOilci:  Abei.,  nnd  observing  thii  lcmperatur«  nt  which  Ibo  mii- 
turo  of  ra[>our  and  air  owr  ihc  [Milrolviitn  can  Ju»t  be  ignited.  Ex 
pertence  Has  shown  thnt  then.'  is  no  dangL>r  witli  a  flash-point  of  40^  C. 
Larxe  quantities  of  petroleum  come  into  the  market  with  a  Aash-point 
of  S'2°-S4''C-;  theso  are  (h«  cheaper  kinds,  vhtch  are  lucd  by  th« 
largiat  proportion  of  thu  ixipulatton,  and  constitute  u  grt-nt  source  of 
danger  from  fir«.  It  would  bo  very  adrnntagenus  it  tho  law  insiiled 
apoti  a  flaah-poiat  of  about  40°  C,  wtiich  hits  ulrowly  beeti  adopted  in 
itome  countriea. 

The  nortion  of  th«  crude  petfoleum  ■which  doea  uot  distil  below 
300'.  but  remains  in  tho  still,  ie  named  vtiseUne.  It  'm  n  scmi- 
eolid  subatHuce  ttt  urJiimrj-  tcmpcratureB,  wlitt«  wlicu  {lurv,  and  is 
QBcd  in  phannary  ia  tho  prepaiation  of  ointments.  It  is  fuHhrir 
rnnde  Ui^n  of  /or  mrering  the  aiirfaoe  of  metHlltc  artidea  to  protct 
th«m  from  oxidation,  fnr  wliich  purpose  it  ie  bettor  than  fat, 
because  the  latter  tumi>  sour  and  then  attacks  the  Burface  of  the 
metnt,  u-hereiut  vaseline  has  u  ueatrul  reaction,  and  remains  un- 
changed in  the  uir. 

Pftra^n-wax,  as  olrcftdv  moniionbd,  ie  a  raixturo  of  tho  highest 

memb*>r«  of  the  8prio8  C„II,„^,.     Some  kinds  of  rrudo  petroleum, 

uotAblv  that  obtuined  from  Java,  contain  oonKiderablc  rjuniuities 

ol  th««e  highest  members,  which  occur  to  only  a  email  extent  in 

'American  petroleum. 

Ztqmd  paraJHn  is  »  product  of  high  boiling-point,  obtained  in 
the  dry  difltillatiou  of  bro«-n  coat 

EiiTUi-wtix,  or  otol'tTite,  is  fotind  in  Onlicin,  nnd  coneUte  chieBr 
,  of  paraffin.  Thifc  substnucc  h  alto  obtiiinml  in  the  dry  distiUatiuu 
I  of  tbe  brovn  coal  lound  in  Saxony. 

U.  Petroleum  has  probably  been  formed  from  fals  under  the 
influoDCO  of  high  luiuptraiure  oomblnod  nilti  gi-eat  pressuni.  In  fact. 
Ekuleu  has  obLaniod  a  liquid  ver}-  fiimilar  to  Atnorican  potroleum.  by 
dlsttlUng  these  substances  under  lourease'I  pressure.  Opinion  is 
dlTKlfid  concenimg  the  origin  ol  theee  fats.     Acajnlinif  ti>  some,  ihcy 


HOMOLOGOUS  SERIES, 


4> 


ar«  doe  to  fiih;  but  it  is  difficult  to  undflrstnod  how  tbo  enormoiia 
quantities  of  iwtrolfum  found  in  Biimeiilacwtuuiildlinvclnwiifornietlla 
tbift  wny.  Anotlier  oiplimnlioii  aliribuies  its  (onnatiou  txi  TAf}-  ftmall 
orgftnisms,  ciillird  Uiatoma;  tlji:»e  v/evo  present  in  enormous  numbers 
in  the  «arli4>r  gMilngit^al  itcnc«J».  "i'hi-y  priuliicod  n  «ort  of  Wftx,  whioli 
yields  ifotraiuum  vihea  <li»tillfd  utidcr  prcsBun:. 

Anollivr  hypolbcsts  line  b^mi  $ii^i.'t^(«(!  by  Moissak.  Tfabaitributes 
the  (orniatioQ  of  pntroleuro  to  the  action  of  water  on  certain  metallic 
carbides  vrhich  ha.Te  been  forniQi]  by  the  intense  hetit  of  rolciiaoMt. 
On  trcatm«til  vrilli  water,  inoil  of  tbeaiivarbidvsj'iolil  giutcoua  bydro- 
caTl)oii«,  tt«]tt'i;inl1y  inotbnuv  or  ftvulylotiv.  nnd  ir  Itus  biH-u  proved  thnt 
tb«  latt«r  ^leld  a  pctrolcum-bkc  liquid  when  cipotcd  (o  high  pressure 
aud  temperature,  Siuoe  petroleum  vnrics  gr«atfy  in  composition,  ac- 
cording to  tli«  placo  wbora  it  baa  been  oblftined,  it  is  poesible  thai  ij(>tb 
bypotlie&es  are  truu  {'^'.  13$}. 


HomalofcouB  Series 

3S.  Ench  at  the  hydrocarbons  CaH,„„  tliffcra  in  composition 
from  tho  Twt  by  rt  X  OH,,  n»  is  At  once  ii<i*n  from  the  goueral 
forintiln.  It  hns  lw«Ti  nlrondy  pointed  out  that  tliin  difTtreneo 
exer^^is^ft  but  n  slight  influence  on  their  chemiral  prDjiorties. 

Whenever  organic  compoiimls  show  grfitt  rt'senibliince  in  their 
ch<>mical  prnpertiea.  and  have  at  tho  eunic  tiniu  a  dilTorcnce  in 
composition  of  n  X  CH,,  thcvurv  Buid  to  bt-  hrjmohfftnts,  the  name 
homoiogovs  $9rtM  being  given  to  siioh  &  group  of  compotindB. 
Many  of  theae  Beries  are  kuown,  as  will  ha  se»n  later. 

It  is  easy  to  nndorstatiil  how  much  this  eimptilles  the  atuily  of 

organic  ch«?mistry.     Iiisteu-il  of  having  to  consiiior  the   chemical 

properties  uf  cuclt  compouud  individually,  it  ia  stifllciunt  to  do  ho 

for  one  rnvmbiT  of  a  homologous  serica,  as  this  givce  the  principal 

characteristics  of  all  the  other  mcmbe!"*.       In   addition    to  the 

mnin   properties  (common  to  oadt  member  of  u  bomotogouii  iierit-s, 

ihoro  HTQ  pecul  iaritiei)  special  to  each  iudividusl  member.     Except 

ill  A  few  intitAncea,   tiiis  book  will  not  dwil  with  tlic*c,  because 

iliey  only  nuod  to  be  coiuidDrui  iu  a  laorc  extensive  survey  of  the 

subject. 

36.   Tho  phyticat  properties,   fmch  aa  the  melting-pnints  and 

boilin^-]>oiiit8,  specifiR  gravities,  and  mol it bi lilies,  of  the  memlirrsof 

11  hnaiologona  series,  generally  changf  uniformly  uk  the  immhor  of 

varbon  atoms  incrciweA.     In  general  it  may  be  euiJ  that  the  melt- 


4* 


orcask:  chemistry. 


fa)g*pcnDM  and  boiling-pomU  rimt  from  the  lower  to  the  higher 
members  of  a  homologoas  series. 

A  table  of  Bome  of  the  phvHtcai   conatontft  of  a  nnmber  of 
Donoal  members  (iO>  of  the  puraffin  scries  in  given  below-. 

It  is  Been  from  thia  table  that  iho  first  four  m<>mben  are  ga««6' 
at  the  ordiiiarr  t<'m|>9rainre,  tho«e  from  C^  to  C^  liquids,  anil  th« 
higher  mumbvre  solids.  Although  raetlian«  m  odonrlee^,  the  litiuld 
members  have  a  characteristic  petroleum -like  smell;  the  »o1id 
members,  on  the  other  hand,  are  perfectly  free  from  smelL  The}' 
arc  all  ulmotit  iue«lDbl«  in  vat«r. 


I 


Fir*  inula. 

Hua^ 

IMttM- 
pDac 

potai. 

SpkUo  Onritr- 

CH. 

M«itiKn« 

-IW 

-!«• 

0-4l5(al  —  m*) 

C.H. 

>:ttia»e 

- ITS-l* 

-  s*.r 

0.44S  (mi  0') 

c.n. 

Prapuie 

-  ar 

O-OM  (U  «*} 

C.H.. 

Bbuiw 

r 

0S«7  iai  U'] 

i-,n„ 

P«nUa« 

«r 

c.ll.. 

UrZADv 

w 

0-«W(«tM*) 

C,[|,. 

[lepUiD* 

•r 

0-W8  ..    ., 

c.ll.. 

Ueune 

iw 

O-TUt  „    ,. 

C-.H.. 

Nonati* 

-  a' 

ISO- 

0-718  ..    .. 

C't.U.. 

I>*caTi« 

-  31* 

ITT 

0-780  ..    „ 

C,,l].. 

VodnrtJi* 

-  28" 

Ito* 

0-7?4  at  lite  meltlng.polat 

C.IU. 

IkudfVBIMI 

-  13* 

814" 

0-7W 

CHm 

ttinAtvt,a* 

4° 

2S3- 

0-""5  

C„H.. 

HexKdMKBa 

18' 

28r 

0-775  

f.,11., 

EleoMae 

87° 

ai»'» 

0-7T8  

*-\,»u 

HMialMHu>n« 

«)° 

sir 

0-778 , 

t«H., 

'I'rieuwiv 

«■ 

*M* 

0.77» 

c„n.. 

nviilri*coiit«n« 

68* 

802* 

0.78!  

C,.IK, 

FrnuirIacoDUfi« 

tv 

881* 

0.788  

Ci.lliti 

li«iftMintana 

lor 

■  At  IS  mm.  ftri 

•.■in.  uiil  III. 

■tinn  fur  111 

H>  follumluf. 

It  should  be  further  remarke<l 
meltin^-pniiita  and  boiling-points 
ben  of  the  series  become  Bmuller 
carbon  atoms.     Thi^  phi-uoniunon 
serieo. 


that  the  diSerenoeg  between  the 

reKpoctirelj  of  sijccesaivu  mem- 

with  inereose  in  the  number  of 

is  usually  found  in  hooiologoug 


iBomeriam  and  Straotnre. 

87.  There  in  only  one  snbstanee  known  with  the  fominia  CH^; 
this  l«  mpthane.  Simllurlr,  there  is  only  one  rompound  having  th* 
formuln  P,II,.  ami  one  with  the  formnla  C,H^     There  are,  how- 


l!iOM£RISM  AUD  STRUCTURE. 


Ai 


ev«r,  two  I'umpoiinils  known  vith  the  formula  C,II,,,  three  with 
tho  fnmiuin  C,H„,  five  with  the  formula  C,7I,^,  ete.  The  phe- 
tiom<-)ioii  of  two  or  moro  comiionnds  boiiig  repreaeLtod  by  ouw 
fomiulii  u  c-ulli-cl  ifiorriTiVm  (2).  iiiitl  coit)iK>iuiilii  buviiig  tht-  same 
fommht  arv  c&llud  tjiomern.  This  iit  cxpluiiiL'il  by  a  ronsidcnitioii 
uf  the  way  iti  whk'li  the  utuiuK  Ar«  {croiiix^d  in  the  iiioloctile. 

One  of  two  )iy[)othoiicii  niuy  he  udflptod.  In  the  tiret  place,  the 
urmngctnent  of  the  atoinH  may  bo  regarded  aa  continually  chuiig- 
inp,  a  molpnule  heing  rpprcfiented  iut  like  a  plauetHry  ayMtpzii,  the 
conRgunilion  of  which  rhungi-K  from  moniL-nt  to  niuuiRiit.  Thin 
hypothodifi,  however,  cannot  t'xpliiiii  the  jOiviiomcnon  of  ieomDriHtn; 
indeed,  it  is  not  apparent  how,  for  example,  the  fuiir  curhoii  atotiu 
and  ten  hydrogen  atoms  in  butane  eoiild  form  two  different  m\>- 
8lanc«d  if  th«  nmingement  wore  Indetenninate,  for  there  are 
trillions  of  moIeculcR  prcwnt  in  hr_ little  as  one  ciihic- millimetre, 
and  nil  Uie  jwgiiihle  coiifign rations  of  these  foiirt<>Bn  ntoniii  niiiiit 
ther«fore  be  nuppo»ct1  to  occur  overy  moment. 

Isomensm  can  at  once  be  underetodd  by  asenming  that  there  is 
a  defiuile  and  uncbaugiug  urnmgeineat  of  the  atoms  iu  the 
molecule,  becauoe  the  difference  in  the  prupertios  of  isomeric 
componiide  may  be  then  explained  by  a  differenoe  in  tho  arrange* 
meut  ol  equal  number)*  of  the  same  at«nu>. 

A  deflnit«  and  oncliaiigiiig  arraugouieQt  of  tho  atoins  in  a  molA- 
eolfl  doeanol  involve  (heir  being  iniiDovabte  in  relation  to  one  another. 
Tbey  may  L>e  suppoeed,  fur  exaiu[>le,  to  revolve  round  a  pusitioa  of 
•tiulllbrlum  wilhout  any  alteration  iu  their  onler  of  tuccesslon. 


88.  Since  tin*  phenomnnmi  of  iaomeripm  leads  to  the  assunip- 
tioD  of  a  deduite  arr^ugcmotit  of  the  atoms  in  the  molecule,  it  13 
necesdary  to  answer  the  (|ue»-tton  as  to  what  the  arrangement  of 
the  atoms  in  the  inolemilcs  of  different  coiiipontii]);  in.  The  start* 
ing-ixiiut  for  Ibis  is  the  tetravalency  of  tlie  carbon  atom.  In  the 
omso  of  methane  the  arrangement  of  the  atoms  may  be  repreavnted 

by  the  formnla  ('^<it-  ii  which  the  four  linkinga  of  the  carbon 

iit«m  ttX,  aa  it  were,  like  four  points  of  ottraction,  each  one  hold- 
ing a  moaovalent  hydrogen  atom  faiit.    Thig  is  the  only  possibility. 


44 


ORQ^MQ  CHEMISTRY. 


bcciiuae  tlio  hydrc>gon  atoms  csnnot  be  bound  to  one  another,  eiaoe 
the  only  point  of  attraction,  or  fiiugle  linking,  of  each  of  them  ia 
alreudj  in  uuiim  with  oiiu  of  l\\v  linking  of  the  cnrbon  atom. 

Wo  shall  now  try  lo  lucertain  l.ltc  anungoinent  of  the  atoms  in 
ethano.  C^H,.  This  8iibstancc  can  be  nbtainod  hy  the  action  of 
aofiiiim  uiHiji  methyl  iodide,  C1I,I  (31).  \Vu  have  here  a  teira- 
vbIviiI  carbon  atom,  three  monovalent  hydTOgon  Atoms,  and  one 
monovalent  iodine  atom.     It  must  thereforo  bo  rcpri}Bent(>d  thus: 

Sodiam  Msotfl  with  methyl  iodide  in  nuch  n  way  that  the  iodioo 
fttuHii!  are  abstracted  from  two  nioleculee,  with  formation  of 
ethane.  The  removal  of  the  iodino  atom  has  the  effect  of  setting 
free  the  carbon  lirikiDg  previously  attached  to  this  atom,  with  the 


production  of  two  groups  H-^C — . 


SiU'Co  the  formula  of  ethauti 


ia  C,H,,  it  is  evident  that  the  only  possible  arrangement  of  ita 
atoms  is  tho  one  in  which  the  two  froe  linkinga  of  the  methyl- 
groups  are  tuiited  to  one  another: 

H-5(— C^H 

The  aTTangement  of  the  atoms  in  propane  can  be  determined 
in  nil  exactly  nnalogons  manner.  It  hiis  boon  mentioned  (31)  that 
propane  I*  formed  by  the  action  nf  ^nilinin  on  a  mixtnrc  of  methyl 
and  ethyl  halidc.<<.  Sinre  ethane  nan  be  prepared  in  the  way  iu«D- 
tioQcd  above,  tho  formala  of  an  othyl  holido  can  only  be 


vhere  X  rnprewnta  a  halogen  atom.  ■ 

Tf  ll'o  halogen  ii  talten  away  from  this  and  from  methvl  iodide 


fSOMF.RISM  AND  STRUCTURE. 


45 


■t    the   mmv   time,   the   rasidaea  units  together,   alioving    that 
propane  hius  thu  followirg  rtrncturo: 

II 

Hv  J         /H 

H/      _^      XU 

"or  shortly  H,C-CH,.CH,. 

An  arrang^meiiC  at  Bvmbola  like  this,  whtt^h  expreRses  the  con* 
B^iration  of  the  atoms  iu  n  maIt;ruU<,  thus  indicating  the  form  or 
Btnidture,  U  called  a  struclurn!  or  constitittimal  formula, 

39.  The  foUowini;  example  mukos  it  clear  how  caww  ol  isomor- 
ism  CUD  bo  uxphiiDed  hy  differences  in  Blnictiiri>.  Among  the  flT« 
k  nowii  hcxaues  there  is  one  nrhirh  Itoils  at  69"  nnd  has  a  epecific 
gravity  of  0-6583  at  aO-O",  and  another  which  boils  at  ^S"  and  hiu 
a  specific  gravity  of  00701  ut  17-5".  The  firet  ia  oht^ned  by  tho 
action  of  sodinm  on  normal  jtropyl  iatlide,  CU,-CI[,. CU,!.  It 
follows  from  what  haii  been  gaid  ahore  that  thie  hoxADO  mu«t  haw 
Iho  Btnjoture  ■.'.  l/,i/  / 

cn,.cH,.cn,— cii,.cH,.cUr        ^-  i ).  -\-\^'^ 

It  is  Cflltod  tiipropifl,  on  tho  asxiimption  that  it  has  been  lonnrd 
by  the  union  of  two  propyl-groupn. 

In  addition  to  this  normal  propyl  iodide,  an  isomer  is  known 

liaving    the    name     ixopropyl    imtiile.       Itoth   eom|inuni)a   can    bo 

eti«)ly  nonverted  into  pruiMine,  CI(,  ■  ClI,-  CIl,.    Awnming  that  the 

ifuimmsiii  is  due  to  n  different  arrangement  of  the  atuma  in  the 

molpculv.    it  follows  that  the  iitomeriiim  nf  the  tvo  compounds 

(',ir,I  can  only  be  v^cjtlaincd  by  a  differpnre  in  the  position  occu- 

pitd  by  thu  iodine  nioni  in  the  moleeule,  beL-atiHo  the  arnitigement 

of  the  atoms  in   propane  is  known,  and  the  propyl  iodides  only 

differ  from   propane  in  having  one  of  the  hydrogen  atoms  in  the 

litter  replaced  by  iodine.     Isopmpyl  iodide  niudt  therefore  bars 

ihe  structure 


t 


U 
C11,.C.C1I,, 

I 


the  conetitution  of  normal  propyl  iodide  is  CH,-CH,-CH,I. 


4fi 


ORC^mC  CHEMISTRY. 


The  hftxano  boiling  ttt  58°  is  produced  by  the  nction  of  tiodiuni 
oti  i^opn<]vyl  iodide.  From  tlii^  uictliod  of  fonuutiou  it  is  evtduni 
diac  tbid  hcxiine  lias  tlio  Ktruoturc 


or 


CH,-cn-cij, 

CH,.CH.CH, 

For  this  mason  it  iti  uilled  iH-improptfl. 


^«;>CH.CH<^g;. 


CM, 


cH,-C-C--t*(, 


CarboB  Chains. 


CN, 


40.  It  is  evident  from  the  f<jregciiig  that  the  faota  nec«eutat« 
the  asfliimption  of  a  bond  bt'tween  carbon  stonui  in  the  mole- 
onles  of  orgttuic  coui|M>iiudH.  77jm  bond  is  a  v»ry  ttrong  one,  for, 
an  we  liHTt*  ttlreadj' 8«eD  (31),  the  itaturat«(]  hydro<^rbonii  resist 
the  action  of  powerfnl  chemifjil  nvj^iiU,  Tliv  [irupcny  piMweased 
by  carbon  atoms  of  combiuitig  tugetber  to  form  u  acri«8  of  msnr 
atoms,  a  rarhtm  chain,  lilce  that  in  th»  hexautfti  abovr  dcacribiH], 
funiiahcs  a  marked  dietinction  bctv-ei^n  thetn  and  the  atoms  of  all 
the  other  okments,  which  either  have  uot  this  power,  or  only  in  a 
Tory  inferior  degree.  The  fact  that  the  nnmber  of  earbon  (-om- 
pounils  is  so  enormous  in  due  tu  tliia  propertv,  in  cunjiuictiuu  with 
tho  tctravaliL-ncy  of  thu  eurbon  atom. 

A  caTboii  ehaiQ  Ukt^  thut  iii  normal  hi^xane  (dipropyl)  is  said 
to  bo  normal.  On  the  other  hand,  thore  ie  tho  branched  chain,  iin 
•xamplc  of  whinh  ia  furnished  by  di-ifiopropyl.  >iiob  fsrbnn  atom 
in  the  normal  ehain  i«  linked  dirtfctly  to  not  more  than  two  others; 
in  branched  rhnini;  there  are  carbon  atoms  whieh  are  dirently 
linked  to  throe  or  four  others.  A  normal-chain  compound  in 
usnallr  denoted  by  putting  n  before  itH  name;  branched-f^tiain 
compounds  arc  often  diHiug-uiehed  by  the  prefix  iito. 

A  few  otiior  definitioni;  niny  tind  a  jdacc  liere.  A  oirbon  atom 
vhioh  is  only  linked  to  one  other  onrbon  atom  is  oallod  primary. 
Tf  it  is  linked  to  two  carbon  atoms  it  is  nametl  sfcondary;  if  to 
three,  tertiary:  if  to  four,  i^ualernartf.  A  rwrbon  atom  situated 
*  at  tlie  end  of  a  chain  is  called  lertninal.  1'lie  carbon  atoms  of  a 
chain  are  dietiugtiished  by  numberu.  the  tcrminul  one  being 
denoted  by  I,  tlie  ono  next  it  by  S,  etc. ;  for  example, 

CH.aH,.CU,.CU,. 
I        8       a       4 


NUMBER  Ol-  POSSIBLE  ISOMERS. 


47 


Sometimes  %\w  tcrminiil  atom  is  donoted  by  to,  the  one  linlted  to 
it  bj  II,  and  the  jtuet-evding  one  by  fi,  «tc. 

L>w  of  Uie  Evas  Smnban  of  Atonu- — The  number  of  hytlroKen  AU>ma 
In  t)i<!  saturateO  hydruoHrbotis  uiiisl  bi-  an  even  one,  !<iaoe  their  formula 
in  Cail*n>i.     All  uth«r  OFKanio  uompouiids  uiAy  Iw  re)!;<inlpd  ssbeiDg. 
denv«<l  by  (]]{!  cxchHng«  of  iheRehj-drogeii  ncnriiK  W  ottiur  pltfiiieiiu' 
orgroujifl  of  aioms.  or  by  llic  ivmoval  of  an  ov«n  number  of  tiy(lro);eii f 
maniit,  or  by  bolb  cAUses  ftimultauvouBly.     It  follovs  from  this  thAtj 
Ibc  ftUiD  uf  the  Atopis  nilA  unevon  valency  (hjdrostiu,  the  hxlogeiu, 
iiilrugvri,  ]kliCKi|ihorus,  cic.)  must  always  be  nn  cvf^n  [inmber.    The 
moleculs  of  aeubstftDcc  vrtiuw  empirical  compusilioii  is  dUiXUi  must 
be  at  lea«t  twicu  an  great  »s  this,  bec»ufte  311  -i-  IN  »  uueriiii. 


Vumber  of  Fouible  Isomers. 

41.  The  tctravatency  of  the  citrlion  ntoni,  couplvd  with  tbe 
principle  of  the  format  ion  of  cbsitis  of  RtomB,  not  only  euabtm  us 
to  Ji''<'<tuiit  iiii  the  Jsomors  which  art>  known  to  esiBt,  but  slso  piitg 
us  in  tlie  position  tif  bi<ing  nble  to  preilift  tlio  existence  of  rom- 
p«Hinde.     For  a  compound  C',Hi„ ,  for  c-xamplt*.  either  the  structure 

Cn,-ClI,.rH,.CH,  or  ^:]}»>Cn-rn,    may  V  atwnmed.  »nd  in 

this  case  there  aro  no  furthtir  possihitities.    Pentune  may  havo  tbe 
following  structural  formulii;: 

(1)  C'H,.CH,.CH,.CH,.CH,:  (3)  OH..CH,.Cn<g^; 
(3)  ^5»>C<?5. 


CH. 


CH," 


For  heixauo  the  following  firo  arfi  posubic: 

(3)  CH,.CH,.CH.cn,.cn,:  (4)  CH,.CH.CH.CH,: 
CH,  CH.OH. 

/CH, 

If  the  principloa  given  above  be  oBGumed,  it  will  be  impoiuiibto  to 
find  i^rni'tiiral  f()nnul»'  other  than  tlioee  «ientione<l. 

Should  it  he  jiottiiible  tu  actually  uhlain  the  same  uaniber  of 
isotntTs  u8  can  bv  thus  jirvdictod,  and  uo  more,  and  shonld  the 


TRGANK  CHEMISTRY. 

pnxlacts  of  syntKoeie  or  decom^iositioD  of  the  existing  isomers 
ii^eedsitAte  tlio  Kssumption  of  the  enme  ainicttinil  forinulie  as  ttioeo 
n'4]inriMl  by  tho  tbi>ory,  thcM?  fiu^u  ouiigiituto  a  very  iniportaut 
conflrinatiriii  of  the  correctness  of  rhe  priitcipW  u^Ktn  which  th» 
theory  is  based.  This  has  in  f«ct  hven  jiritveil  to  hol<l  good  Ui 
iiuinerons  iiistaiicce.  ait<]  therefore,  on  the  ciher  hand.  nfTorda  an 
iniportaiil  means  for  determining  the  structure  of  a  compiHiiid. 
bacauae  if  nil  the  RtruL-turu)  furniiiliB  which  are  posaihlt!  for  tlie 
oompoiniil  at'oonling  to  tho  ihoorj-  are  t*oii«ideivcl,  oin'  of  them 
will  bi'  found  to  be  that  of  the  (tubstiinw. 

In  very  many  tases  llio  number  of  isomers  ut'tuidlr  known 
in  niUL'li  similier  than  that  whicli  is  posaiWc.  Thi«  it  due  to 
the  f«i-t  that  ihv  nuinl^er  of  iw^ible  iBonit;r«  iiicrviiH-s  very 
qnirkly  with  incroiisc  of  the  number  of  rarboii  ntonie!  in  tho  com- 
poiniil.  t-'AYi.RV  hiis  calculatfJ  that  lh«re  arc  nim'  possible 
isoniere  for  f,!!,,.  ciglitBen  for  f,!!,,.  tliirty-fivo  for  t',H^, 
seventy-five  fur  t'l^n,,,  oiiu  hundrtd  and  fifty-uinL-  for  C„Hj,,  three 
hjindred  and  fifty-foiir  for  C,,!!^,  eight  hundred  and  two  for 
C'„lt„,  etc.  OheniiEls  lutvo  not  Irieil  to  prvptiro,  for  example, 
cvei7  on«  of  the  eight  hnndred  and  two  possible  iwniera  of  the 
formula  t'i,H^.  bocmiee  their  attention  hun  been  oecupietJ  by  more 
important  proMeniB.  There  ejin.  however,  be  no  doubt  as  to  tho 
[xi^ibility  of  obtaining  all  these  rnmpo\ind»,  because,  as  mentioned 
above,  the  metliodi)  for  building  them  up  are  ktinivn,  and  there 
would  therefore  be  no  theoretical  diHiniltics  in  the  way  of  tbeee 
experimcDtSj  though  there  might  be  hiudrauccB  of  an  experimental 
nature. 


FhTueal  FropertiftB  of  Iiomerie  Compoondt. 

42.  Th[^  norriiitl  compound  has  (be  highest  boiling-point  among 
the  diffcreut  iaomere,  and  this  rule  holds  gooil  in  generul  for 
liomologoua  .icriei;  other  than  that  of  tho  methane  hydrocarboiid. 

K:/ample.  Xdrninl  hexane  boils  at  tid°,  and  the  buihng-pointa 
of  the  different  iconic r.r  are: 

Mcthyldiethvlmcthane :  {C.II^.CU  ■  CH,  11.  P,  (J4». 

Kthyliwbntyl:  i;,U,-CU,-C-Il(CUJ,  „    n\ 

Pi-ieopropyl;  {CU,|,CH-CII<i:ll,),  „     58°. 

Trimelhylethybnetliaiio:  (OH^l,  C-C,H,  „     48°. 


I 


ALCOHOLS.   C„n^.,0. 

Kethods  of  Fornuttion  and  Conatitntion. 

43.  The  aiomUrs  of  tliia  homologous  soriM  can  bo  obtiinwl 
\iv  th*  action  of  silvpr  hytiroxido  on  thp  alkjl  Jjalldea: 

C:.U.„.,1  +  AgOH  =  "CJCIIo*!  Agl. 

It  is  iiBuul  tu  bring  un  alkrl  iodide  in  contuot  witli  moiitt  oiido 
of  etlvor,  of  whicli  tbv  (lurtiou  dissolved  iu  Lliv  wtitcr  rearU  like 
aiker  hydroridc  {"  Inorgnnio  Chemistry,"  246).  The  prepurJitiou 
of  the  nlcotiol  from  llio  i>(>dide  c^n  also  bo  cfTpctoil  by  heating  it 
with  oxcesg  of  water  ftt  100'^:  f    j,,/^!/ 

When  stxliuKi  reai'ta  urith  an  ali'uho]  C„il,f,„0,  one  grHmine- 
stom  of  frpc  liydrofteii  ifl  libcrulud  from  racli  grnnimfl-niolpnile  of 
tlie  rtlcohul,  ntul  H  ortmpoiiiid  nillcd  soilium  nkohohlt  witli  the 
formula  CBH,„.,NnO  is  prndnodd,  whifh  (luoomitoiws  in  presence  of 
es<'<>sii  of  wfttiT  into  XnOll  mid  iin  nloohol.  The  gudiiiin  hat:  thus 
repUif»«l  one  atom  of  bydmgeii,  auii  neith<^r  il  iior  stiy  other 
inrtui  cttii  reiilacp  more  than  one  hydrogen  atom;  if  exoesii  of 
sodium  is  adde<l,  it  ivmuinii  iiiiucted  upon.  It  follotts  that  iliere 
is  only  one  bydrogon  atom  in  tho  *lcohoI  which  is  rcplac«iible  by 
Bodinm. 

When  lUi  alcohol  is  tn>ated  n-itli  trichloride  or  peDtaohlorido 
of  pho4pboniit.  au  alkyl  rliloride  i»  forrned: 

3C.H.,..o  +  PCI,  =  3cX..oi'+  tr.Po.. 

Vie  ehall  iuid«aroiir  to  deduce  the  coustitutioa  of  the  alcoholt 
from  llicB*  faets.  Silver  hydruxidp  ran  only  hn%'p  the  structure 
^g — 0 — H,  its  divalent  osygeuatoni  being  linked  to  itsmonoTAlent 
silver  and  hydrogen  atoms.  AVheii  eiWer  hydroxide  is  brought 
into  contuot  with  an  alkyl  iodide,  thf  reaction  must  be  Mippoeed 
to  take  phict;  in  eiiuK  a  wiiy  tlmt  uii  tlir  our  bund  thi«  iodine 
atoin  IB  Mt  fn«  from  the  alkyl-groitp,  and  ou  tlic  other  hand,  the 
eilTcr  atom  from  the  hTdri>vyl-Kniup.  The  nlkyl-group  and  the 
bjdroxyl-grouparo  ihuK  afforded  llii*  opportunitj- of  nnitiiig  with 
oue  mnother  by  means  of  the  linking  vliich  has  been  set  fnw  io 
jh  of  them :  


so 


ORGANIC  CHEMISTRY. 


This  methoil  nt  formation  |)ri>ve8  that  tlio  Alcohols  cantafn  a 
hydroxyl-groiip ;  their  preparation  from  alkyl  io4liilo«  umi  waier 
leads  also  to  the  same  eonrlusion,  which  ia  further  siip|>urt^  by 
the  two  properties  uf  alooliole  mentioui:(i  above.  It  iii  evident  that 
if  their  etnictnre  is  expressed  hy  C„IIp„,-OH,  all  the  hydro^^n 
Atomi)  pppaeiit,  ext-ept  one,  are  linked  dirnntly  to  earboii,  wliilo  one 
hydrogen  iitom  oei-iipiM  a  upecnal  position  in  thti  molwiile,  being 
Kttat^hed  tt>  the  oxygen  utom,  wliicli  in  itK  turn  ih  united  through 
itH  Berond  liiikin);  tou  curhoii  iitum.  It  i«  only  natural  to  i<iipp08e 
timt  the  epeeial  jKieition  oeeupiod  by  thi»  hvdrogon  atom  ie  iiMom- 
panieil  by  n  i^pcfiinl  pi-operty,  that  of  being  the  only  one  of  all  the 
hydrogen  Htflms  which  i«  replnocable  by  ttlkali-metals.  Moreover, 
sodium  Ht'tfl  free  hydrojreu  from  another  eomiJcnud  which  witliont 
doubt  cont&ins  a  hydroxyUgronp:  l\\\*.  i-uni]ioiiud  is  wHter,  for 
which  no  other  conatitntion  is  possible  than  II — 0 — II. 

The  fiK-t  that  the  alcohols  are  ccmvertwl  into  alkyl  chloridtK 
by  the  action  of  the  chloridce  of  pbonpliorus  is  porfoftly  in  accord 
with  their  containing  a  hydroiyl -group.  It  is  seen  at  ouce  from 
the  empiriciil  formula;  C„nj„,jO  and  C„U„.|X,  that  the  linlogeti 
bu  replaced  Oil.  It  ni«y  he  assumed  that  in  this  nMietion  the 
hydroxyl  of  the  alcohol  La«  changed  places  with  tlie  chlorine  of 
the  phosphorus  «;oiii pound: 


3(C„H 


A  ronsidnration  of  the  possible  eoustitutional  fomiulne  for  siib- 
stanree  having  the  general  molecular  fonnubi  C^ll^.^O  reveals  the 
ftict  that  on  at'coiint  of  the  vray  in  wliich  the  oxy^n  mom  is 
linked,  only  twu  foriuulie  are  possible;  tlius,  the  i^'ioipounil  C,H(0 
could  be  either 

L  0H,.CH,.OH,    or    11.  CH..O.CH.. 

Since  all  the  hydrogen  atoms  in  the  eceond  formnln  have  the 
same  value,  jteannot  bo  the  on©  representing  an  alcohol,  «*il  would 
not  noeouiit  for  a  very  itnpormul  property  of  these  compoinidg, 
the  ucijon  uf  the  nlkali-metaU  upon  them.  The  action  of  stiver 
hydroxide  on  iiu  alkyl  iodide,  or  that  of  PCI,  on  an  alcohol,  would 
accord  e(|ually  ill  with  this  formula,  whereas  formula  I  explsina 
three  nttctioiis  fully ;  it  must  therefore  be  adopted. 


^ICOHOIS.  C„Hi„+*0. 


S> 


I 


Tlte  coDStitutionnl  formnlic  of  the  alcohols  tmve  thus  been 
dedupfitl  frcnii  their  pmiiertieu.  Invcreoly,  f/te  comiifufionalformti- 
ta>  arrounl  /or  all  the  chemital  properties  of  the  compounds,  being 
simply  a  abort  way  uf  expreising  th«m.  It  is  easy  to  soo  how 
valuable  thcne  formulii!  ure;  bec»iiiii>,  if  it  is  prt^giblo  to  derivu  a 
structural  formula  by  studying  eorae  nf  the  properties  of  a  com- 
pound, it  vill  be  possible  from  this  to  deduce  its  other  properties. 
The  exist«nce  of  propt-Kies  indicuted  in  this  way  has  in  atimcroni 
inttanoes  been  estitblisbed  by  oxponmout. 

Homenolature  and  IiontcriiBi. 

44.  The  alcohols  of  this  eiTiuH  lire  naiiitx]  iifterthe  aIkyI>groupe 
containtHl  in  thum;  for  ('.xam]>U>.  methi/L  eChtjl,  propyl,  etc?,,  nlcoliol. 

Isomorisin  may  arise  in  three  waya:  by  bmnching  of  the  carbon 
chains,  through  the  position  of  the  hydroxyl -group,  or  through 
both  thc«e  causes  simultaneously. 

This  19  Been  from  the  following  tabic  of  tlie  iHomcrio  alcohols 
C,  to  C,: 


JTuMl 


nvpft  alc«hoU  OtHfO 
1.  N<iniial 
S.   Isn 

1,  Nomitl  prinur7 
S.        „       wMondujp 
S.  Uti 

4.  TriraMbxIcarbtnoI 

1.  Nomutl  pTlmur 

2.  iBotimvkkibiDol 

5,  BMviiiiJftr;  butyli'ArbinoI 
4.   MpiLjli>r(ii<ylcai'biiin1 

S  MoiliylisormfiTlorbinol 

•.  Di'tthylcariiiiiiil 

7,  Iltmotli;!"!!!  1  kvrbinul 

•.  Tenlar;  butjIcKrbinol 


Fomulk. 


cn,-cii,-ai,on 

CIl.-CllUlI  CH, 

CH..CH,.CH,-CH,OH 
CH.CH.rHOH-L-U, 
(CH.).Cti.CU.OH 

CH.  ■(«!,).  ■CU,OH 
(CH.l.CH-Cn.-CU.OH 

.<CH.i,CH.rH0H-t1i. 

,c,ii,-iiroii.i,H, 


aoiiiDK- 


er 

117* 

100- 

103* 

88- 

188* 
181* 
138' 
119' 
113-8' 

ur 
loa* 


0-SOi 
0-7B» 

0-810 

0.80S 
0-7M 

0-815 
0-810 


The  names  containing  carbinol  ha\e  rcferenoe  to  the  fttct  that 
•1)  ulcohohi  may  be  looked  upon  us  methyl  alcohol  (citrlinol),  in 
vhirh  one  or  more  of  the  hydrogon  atoms,  with  the  exception 
of  tho  one  in  the  hydroxyl -group,  arc  replaced  by  alkTl-groH[W. 
Ill  itus  way,  iaobutyl  alcohol  is  culled  ifitpropyicarhinol.  secondary 


53 


ORGAHIC  CHEMISTRY. 


bat^fl  alcohol  meihylethylcarbinoi,  and  normul  butyl  nlrohol  n>j»ft^ 
ftylearlinot,  «to. 

As  is  evident  from  the  above  examples,  a  primary  alcohol  u 
one  in  which  the  hydroxyl-group  Id  linked  tu  u  iirimaiy  carbon 
atom  (40);  vhile  in  a  ttrondary  ur  »  leriiary  alcohol  the  hydroxy! 
18  iiukod  to  u  Becoudary  or  u  tertiary  carbon  atom  reepectirely. 
Similarly,  compounds  which  may  b«  regarded  oe  haviug  been  pro- 
dncod  by  roplactfrnomt  of  hydrogcin  linked  to  n  priniarj',  spoondary, 
or  tortinrj'  atom  are  f«lUid  primary,  set'oudarj'.  ur  ttrtiarj'  com- 
ponnds.     Thns  primary  alcohola  ttro  represented  br  the  genera] 

formula  C„H^.,—CH,OH,    aecoudary  by  C„U^.,— C^C  1I,„.,, 

and  t«rtiiUT  by 


General  Properties  of  the  Alcohols. 

46.  Some  of  the  physical  properties  of  the  aleohnls  are  given 
in  the  following  table,  which  includes  only  normal  primao'  com- 
pou  nds : 


Mmub. 


HMbvt  klcolio] 
ElUyf        „ 
Propyl      .. 
Botyl 
Amyl 
H«yl 

SJ??'  :. 

Nanyl 


FbnauU. 


cn.oH 

CH.OH 
C.H.OH 
C,H,OH 

C.IIuOU 
C.H„OH 

cn,.0H 
c,H„on 


SpwUIC  Urarltr 

liaUliic-polni. 

0-812 

M* 

owe-' 

W 

0-817 

87" 

0-83S 

nr 

o-8sg 

1ST- 

0-8SS 

IS?" 

o-BSe 

na* 

0-S8H 

191' 

0.843 

sia* 

BoUtog.poiDUk 


IS* 

SO* 
SO* 

ir 


It  is  seen  that  there  is  an  increaw  in  the  boiling-poiut  of  about 
20"  for  Dverj-  additional  C"H,  in  Iho  fonnnlw.  A  eirailar  regnlarity 
is  found  in  other  homologous  serie:^.  This  t»h]<>.  togetlivr  with 
that  on  page  A1,  shows  that  the  normal  couipoundi  havu  tlie 
highest  boiling-points:  and  this  also  holds  good  for  the  hydrocar> 
bone  (42). 

The  lowor  alixtboU  (C,  —  0,)  are  mobile  liqnids,  tho  middle 


METHYL  AND  ETHYL  ALCOHOLS. 


53 


jone«  (C,  —  C„>  ar«  of  a  nioro  uitjr  nature,  whilo  tlia  higher  mom* 
hen  urc  Kulid  at  thu  onliiuin'  tt-in|KTnitiirL-:  al)  »ru  calaiiTlctis,  at 
l«?ii«t  ill  thill  Itiycre.  In  thick  luyora  they  arc  slightly  ycUovr,  the 
colour  bi't'oniing  more  tniirked  with  increase  in  thi'  niimbor  of 
caTlwiii  atoms.  The  tirst  mfmbera  (C,  —  C,)  ure  mjHfiiblo  in  nil 
prujiortionii  with  vater.  but  the  solubility  of  t\u:  higher  nieiiibctrs 
tliminiiihes  (jiiicWly  »h  tlm  numher  of  cjirhon  iitninn  in(-reiu>ei(. 

The  lower  tneniitcni  hu\R  ii  »pirituau!i  Hmell,  und  the  middle 
OHM  a  dtsagroc:uhle  one,  vhtlc  thu  eulid  tuvoihcrB  are  odourless. 
Their  dpeciSt-  gravity  is  lesa  than  1. 

Methyl  Alcohol,  CH/>H. 

46.  ThU  Kiibjstance  is  obtaiued  on  the  large  Hcale  by  the  tliy 
diKtillation  of  wood  in  irou  rt-torts  ut  u&  luw  u  tcmperatttro  as 
possible;  or  buttt^,  by  Iroutitieiit  of  wood  with  hot  produfrr-gtw, 
vhioh  in  a  mixture  of  carboTi  iiiouoxide  and  uitrogcn,  ohtaiaed. 
by  paesiog  air  orpr  coke  at  a  white  heat.  To  thc«c  methods  of 
prfrpanition  tlic  mihstaiipe  owes  ita  nanic  wood'Spirii.  Tlio 
productii  of  the  distillation  arc  giiM-'s,  uii  iif]iieou»  liquid,  and  tar. 
Th«  aqiieoiifi  Rolution  (-ontains  methyl  alcohol,  &long  with  a 
Qum)>er  of  other  auhHtanceit,  of  whi«h  the  chief  are  »«*tic  arid  and 
ncfilone.  'Hie  acetic  acid  id  ma<lu  to  combiDe  with  lime,  and  the 
methyl  alcohol  purified  by  fractiontU  dirtillation,  and  other  methods. 
It  is  tilled  in  comnierco  in  the  prepamtion  of  aniliuc  dyes  und 
formaldehyde,  for  the  tlmtiluration  of  Rptrit  so  m  to  render  it  iinSt 
fordriuVing  purimees  (48),  etc. 

Methyl  alcohol  burns  with  a  pnle-hhie  ftame,  and  is  miscible 
with  water  in  all  proportione,  the  mixing  Wug  accompanied  by 
coutnK'tion  aud  the  development  of  hcut.  IXe  nieltiug-poiiit  ii< 
—  ya.W;  its  other  jihygical  propertiee  will  be  found  in  the  table 
on  page  Ti'i. 

Ethyl  Alcohol,  C.HjOH. 

47.  Thia  18  ordinary  ulcoho],  sad  is  prepared  artificiallj  iu 
cuormous  qnantiticB.  It."  prc|>(irntjon  dependa  upon  a  property 
possessed  by  ^hieose,  a  sugar  with  tbe  fnrmiihi  ('(Hu'^'  "'  decom- 
posing into  carbon  dioxide  and  ulcohol  in  presence  of  jftast-celiM : 


54 


ORGANIC  CHEMISTRY. 


About  <J5<(  of  the  glucose  deoamp<»Bes  ^■t.-ording  to  tliie  fiiuation; 
a  number  of  liigber  hIl-dIioIh  of  tliia  fii<ri(>£,  cbiefly  autyl  ateohoUt 
C^„OU,  are  formed  m  by-producLa,  togetlier  with  glyccTol,  may 
cinie  acid,  cto. 

In  Ihu  Luehtiicttl  miiiiufitcliin;  of  ulcobol,  (his  KUgsr  itttc)f  h  not 
OBod  08  »  bmiU,  owiug  lo  iU  boiiig  too  co«tly.  Sonio  xubetaiicc 
rich  in  stjuwh,  (C^H^OJ,,  «ich  an  potatow,  grain,  etc,  ie  u*ed 
instead).  Ry  thp  action  of  mtymtf,  the  Ktarah  is  almost  oomplftcly 
oniiTerteii  into  wn^/ow,  f'^jlI^O,,,  one  molocnle  of  t)iiii  oomponnd 
bring  then  converted  into  two  molecalns  of  glucose  by  th«  HCtiOQ 
of  one  molecule  of  water: 

c  ii„o,.  +  n,o  =  8cn„o.. 

EnxynuM  are  clieiuleAl  oompoands  (unorganized  femnonis)  wbioh 
have  tho  properly,  wlion  oorLain  itubstuucett  am  brought  into  contact 
with  small  f]uantltiM  of  ilioiii.  uf  causing  Itiesosulii^raiicu  toileenui- 
pofv,  in  niost  cases  with  addition  of  ihe  Bletoents  of  water.  Tlicir 
contttitution  and  ibe  way  in  which  thpy  act  are  both  unknown  ^33S). 

Thci  particular  i^ntrmo  wliicii  \ft  uhpiI  in  the  teithnidal  ntanufiio- 
tnro  of  miitloKe  from  Ktarch  ir  railed  ditigianf;  It  is  present  in 
itproitting  barley.  The  n-actiun  to  wbii'h  it 
gi%-e«  rise  li  called  sncrharificaiion.  When 
potatoea  ara  nsod,  thoy  uro  firet  rna^c  into 
n  thin,  homogeneoue  pulp  by  treatment  wttli 
«t.cnm  und«r  proBeitre  at  140°  to  150%  apront- 
ing  barley  beitig  theu  added  nft«r  cooling. 
At  a  temperature  of  fiO"  to  fVi'^,  the  decom- 
position into  maltoee  is  completed  in  twenty 
minatos. 

.:Vfter  the  maltose  solution  has  been  pre- 
pared, yeiut  iti  added,  and  ilio  (<.'rmenlation 
onrrii^  on  at  a  t^mpeniture  bfleto  33°.     In 

order  to  sepitrat'i 
the  recinltiiig  uJ- 
fiohol  from  tho 
other  fmb«t«ucos 
which  aro  prM- 
ent,  the  product 
Fio.  28.-FiiACTi«N^TiN«cyi.uMs.  is    Kuhmittwi     to 

distillation;  hy  using  ik/TaclioHaiiK^'Vot«mH  (Fig.  2;l),  alcohol  of 


WB^M ' 


ETHYL   ALCOHOL. 


5S 


90<t  streogtli  can  hn  obtained,  althotigh  the  oncontratioQ  of  tlie 
alcohol  in  the  fermttuted  llcjuid  drte^  not  <3xceed  18j(. 

The  thia  liquid  rei«idue  remaining  in  the  Ktill  ih  called  gpetii^ 
mvih,  und  im  uanI  Soi  hal'iag  uittlc;  it  contains,  amon^t  other 
things,    alnioiit   all    tbo   ulbuDiinvuB    «ul)Btiuic«8  presont   in   the 
material  from  which  the  npirit  has  been  mnnnfflcttircd. 

The  cruel*  )i|>irit  (low  wines)  so  jirejianid  iii  a^iii  iiarefuUy 
fractioBated,  when  alcohol  o(  iHifi  hy  vohinio  (»pin'lf)  in  ohtaiued. 
The  frartions  of  higher  hoiling'point  consist  of  an  oily  lir^uid  with 
an  iinplea»ant  smell,  which  iB  chilled  fusit  oii,  and  contains  chiefly 
amy)  alcohoU  and  other  homologueii.     Tho  residue  is  called  fijent 

Abntwlic  beveraytt  have  long  been  known.  Tliey  are  closclfled 
into  two  uiain  liivisiona,  those  that,  liftve  Won  alistilldd  nnd  tlioao  that 
have  not.  To  iho  first  clans  Iw^iong  hmndy  (tO-SO*  alcohol),  gin 
(alcohol  diitilled  wi(U  jitniiivr  berrin),  (-vyriac<obtain«d  b>' dialilling 
wine,  Hbov«  see  alcohol),  tjlc.  Tbo  secoud  vlau  includes  be^  (8-4^ 
akobol),  tffint  (S-S-IIMC  alcohol),  madeira  (up  to  21$  alcohol),  etc. 

48.  The  alcohol  of  commerce  (jyiiri/j!  o/wme)  always  contains 
vater.  In  order  to  obtain  anhydrous  or  ahsolule  alcohol  from  thia, 
lunipB  of  qulcli.lime  are  added  to  spirit  containing  a  high  per- 
oenCage  of  alcohol,  imtil  tho  qnicklime  Khows  ttuolf  above  the  eni 
iwx  of  tlie  liquid.  The  latter  is  then  allowed  to  stand  for  some' 
d&ys,  or  boiled  for  sereral  hours  nnder  a  reflnx-con  denser  (18). 
after  which  it  is  distilled.  The  preparation  is  much  facilitated, 
and  the  loss,  which  is  rather  large  by  this  method,  is  reduced 
to  a  minimum,  by  introducing  a  apirit  of  high  percentage  along 
irith  u  little  quicklime  into  a  vat,  which  i^  then  oloeod  by  a  «ercw 
lop,  and  heated  some  hours  at  lUD'^  in  nwater-bntb;  the  spirit 
U  then  diiftilled.  Id  order  to  prepare  abaohite  alcohol  from  dilute 
alcohol,  the  latter  must  first  lie  concentrated  by  distilling  it  from 
a  waler-balh.  This  can  also  he  effected  by  the  addition  of  solid 
jHitawium  carbonate,  which  oaueea  the  liquid  to  eejiarato  into  two 
Inverv,  the  aqueous  cue  bi>Iuw  and  the  alcoholic ou<j  above;  alcohol 
of  01  •&<  by  weight  in  thun  obtained. 

AbsMlule  alcohol  iii  a  aiubilc,  colourless  liquid,  with  a  charac- 
ipristic  dmcll.  ll  solidifies  at  —  112-3\  aiul  burns  wilh  a  jiale- 
Iduo.  iion-luraijioua  fianiu.  It  is  very  hygroscopic,  being  niiBcible 
iritb  water  in  all  proportions  with  contrsctiott  and  rise  in  tetn- 
peratnrc.     The  maximum  contracltou  n  obtained  by  mixing  H 


OKGJiiK  CHeHtSTXY, 


I 


of  alcobol  irith  46  Tolumoi  of  irsur.  the  Tolume  of  tlie 
imhmg  mtxtttre  at  20"  being  i>6-3  instead  of  100. 

A  Met  for  abeolnte  alcohol  u  its  beluTioDr  iritb  anhrdroua 
Mpptmlphatf,  whirh  rematiu  porfectlv  colonrlesA  when  in  contact 
wish  ii,  wbetou  if  the  eltgbtest  trace  of  water  in  present,  the  ixipppr 
Blpbate  derekips  s  light-bine  colonr  after  several  honrs.  The 
tpetHc  gnritv,  a  pbTvic-al  oooBtant  which  is  often  Dsetl  toaocertain 
the  parity  of  itqajtl  compounds,  muy  alau  he  trmfiloycd  for  the  uana 
parpoM. 

On  acconnt  of  th«  (Ttcai  importanco  vbicb  a  knowledge  of  tho 
■moant  of  alcohol  in  mixtnrve  of  wstw  and  aloohol  has  for  indus- 
trial ani]  Gtcol  piirpoRe«i.  it  a  nocesmry  to  bare  a  moinod  for 
qnicklv  and  easilr  determining  thi^  Different  cheniiets,  amonp 
tbcm  VON  BAi'MiiAt'RK,  hare  shown  inat  the  determination  of  the 
ipccific  grarity  and  the  temperature  of  sach  a  mixtnre,  alTnrda  tbv 
easiMt  method  of  effecting  this.  For  iiiis  purpose  a  table  has  been 
prepared  with  gr«at  accuracr,  ubowin^  the  epecific  gnritiea  of  mix- 
tures of  aloobot  and  water  from  v^  to  IWf,  at  tcmperatDres  between 
0"  and  30^  When  the  sfwcifie  gravity  and  temperatare  of  a  given 
mixture  liave  been  deccrmiued.  the  jwrcenta;^'  of  nloofaol  uiav  be 
found  by  reference  to  tbe  tabic.  The  epecitle  gravitT  is  luoally 
determined  in  practice  with  a  delicuto  hydrometer. 

In  coQiinerce  aw]  id  the  artA,  the  lunouiit  of  alcohol  is  usually 
expRSiad  on  tbe  Contment  of  Europe  in  ToiuHie-pertxnlage,  or  the 
nauiber  of  lilrea  of  ab90iut«  kIooIkiI  contained  ia  100  litras  of  the 
aqueout  solullon.*     For  scientifie  pitqMWGS  It  b  naually  expressed  in 

■  In  Ctmil  Britaia  llio  vtuidan]  ii  p^otf-tpSrti,  Tbte  auii«  U  (lerlrM  don 
tlio  aid  iii«iUuiil  tit  l«Bling  i^int  hj  luolMoBing  gunpawd*?  wtth  il,  Md  tlk«a 
I'HifiioiC  tl)"  iniiture  Inhi  oont«rt  with  4  Ilxlilvd  uaMli.  If  the  atcuhol  wen 
"  umlpr  pnrnf."  th«  |M>w(i*r  diil  not  tnka  Or*,  but  if  iltBr«  w»ni  )iu(Eci«nt  tloo- 
liol  prearat,  thr  viiplictlioa  of  tli«  light  igoitvd  Iti*  ganitowdr,  lli«  spirit 
Itrinjc  llxn  '*(ivnr  proof  '  ^Vhnn  ihr  pmpuitinns  of  ■IcoLoI  and  wnter  vrere 
Otioli  tbai  11  was  Juu  pusslUle  lu  mi  fire  to  the  powder,  tlw  utnplw  was  d«> 
Mftbftd  «•  "  pruaf-spirit. '  When  llio  iipirlt  U  iri>«ker  ihaa  proof^pirll  it  iS 
said  b>  be  tijirfrr  protf.  ami  wbro  sirufif,-vr  ih&Q  proof-spirit  Is  said  lo  be  owr 
Jtroef;  fur  exsiii)i1e.  s  xpirit  whirli  i*  V  niKler  proof  would  contsin  in  mkU  100 
Tolutnes  thii  fsniir  quautitv  of  Alcohol  im  ihol  ei>iit<iood  in  Sft  TolamMof  proof- 
spirit,  wul  a  Bpirli  5*  over  proof  woold  nnnil  S  vulnmna  of  wsivi  sddod  to  sacli 
100  vnlunins  to  convert  II  I □  lo  pnwf  Spirit.  B^  ad  of  Psrllamifnt  '  proof- 
spirit  ''  is  dcBnvd  as  "  such  a  spirit  as  *hall  at  a  t«IDpl^ralurt^  of  51*  P  wirigli 
exactiv  4}  of  aa  rqual  uieasure  of  distilloO  watrr.  '  This  corrrspondn  to  a 
spirit  oaaUininft  37 -1%  €>(  almhnt  tiv  voliimoi. or  49'3<  \>f  welglit.— TltAKBi.ATOik 


PROPYL   ALCOHOLS, 


sr 


perociitago  D^r  wctghit  or  tlie  numlMr  of  grammes  of  ntcohol  cotilntiicd 
it)  100  grnramea  of  tlioiiqu(u>uii»olu(ioii,  Thesi>  ]M>ro«ntiiffe-ni)inbrre 
are  iloi  the  Bams,  becauac  contraclion  takes  placa  nh^n  alcohol  and 
watAF  Are  mixed,  so  that  the  peroentagea  b}-  weight  are  smaller  than 
thiiM'  by  Toluiim  for  a  spirit  of  aiiy  ^ivvii  coiic'i;iitn4lioii. 

The  greater  part  of  the  uk-ohol  produced  in  consuraed  in  tha 
funii  of  IjfVcniKws,  the  dftriiiifiitQl  iihys'iolopcul  t-ffecLs  of  whii'h 
nrf  luigjnfutcd.  by  the  imijuritioji,  eapLtiully  fusel  oil,  which  tlifj 
contain.  Alcohol  is  used  in  commerce  for  tlie  preparation  of 
UcqiR-rs,  wnijiihM,  dyc«,  impoTtant  pharma^catiail  proparutiona 
(i^hloroform,  clilorrd,  iodoforin,  etc.);  it  is  also  I'niploved  for  the 
jireeervation  of  anntnniii?j)]  sppcimens.  Alcohol  is  n  good  solvent 
for  niiiuy  organic  compounde,  and  is  widely  employed  in  lahoratury 
work  for  this  pnrpoee. 

On  account  of  tbo  extensive  use  of  alcohol  for  inHnufacturing- 
'"JiptrWiria.  ^'^'^  indiietriee  in  vhich  it  is  employed  would  b«  para- 
^lytM  If  the  uecoBSHTy  spirit  were  subjact  to  the  same  excise  duty 
as  altwhol  inteuded  for  consiimptluu.  The  alcohol  used  in  manu- 
faotiirea  in  kohii-  niitittnes*  is  accordiii(;1y  uiado  unflt  for  drink- 
ing {tltnaiurttl  or  titolkylated)  by  the  addition  of  matcrialii  wliitrh 
impart  to  it  a  lauseoiia  taste,  and  is  sold  duty^fcee.  On  ttio  con- 
tinrntof  £uropo  cnide  wood  spirit  is  used  for  this  purpose,  and  in 
Oroat  Britain  this  is  tnipidcuKintcti  by  tb«  addition  of  it  smiUI 
quantity  of  parafiin  oil. 

A  le»c  for  cthjl  alcohol  \»  the  formation  of  Iodoform  on  the  add!- 

tion  of  loditiA  ami  cnimtic  putmh  |152). 

Propyl  Alcohol*. 
4&.  Two  propyl  alcohols  un;  known,  onr  boiling  at  0"°  and 
having  a  Bpeciiic  gnivity  i»f  0-804,  the  other  boiling  at  81"  and 
haWng  ft  apeoitic  griiTity  of  0'78fl.     In  accordance  with  the  prin- 
ciple/ whiiih  Iwive  heen  stated,  only  two  isomers  arc  poamblo: 
CH,C1I,-CH.0H,  and   cn.(;u{oiD-cn.. 


"TlMMleof  dDi7-(r««  alntliul  1b  not  |>«ruillu-^  iaib«  I'liiiod  Sutce ;  a  las 
Ik  leir)*d  of  91.10  p»r  proof  gallon  (So;!  niooltol  by  volume),  nr  f  S.07  per  stand- 
ard galloQ  (S31  cubic  incliPB  nf  94S  alcnhnl  l.y  Tnlnrnii),  sad  f*  a  bsATj  bgnl^a 
on  nianv  iti<lQMrt«i).  Tbe  duty  in  muoh  hiKlicr  iu  Urcat  Hriiain,  Ix^ing  11«.  ptr 
^tU>n  iif  proof  .fipiril  (Britiuli  Miindnnl.  p.  96).  ti\it  iIiih  illMilvantagH  Is  In  somo 
n»casari>  Odonterbalaitced  by  Lhn  salo  or  daty-fivo  iu«tbyUU!d  aplril  for  nianu- 


58 


ORGMHIC  CHEMISTRY. 


Whif-h  Btrnptare  Iim  to  bo  aligned  to  the  laibstaiico  with  the 
bighpr  boiling-point,  and  which  to  that  with  th<;  lowpr,  tnity  he 
determinml  by  eubmitting  the  siibstancra  to  oxidiition.  From 
each  of  these  Alcohols  ta  thus  obtAined  a  compound  vith  the 
formula  C,lI/>,  but  these  oxidation -products  are  not  idonticul. 
"Mt'hcn  they  are  further  oxidixoci,  the  compound  C,U,0  (propioii- 
uldehjde),  obtained  from  the  alcohol  of  higher  boiling-jxtiatr 
j'icldH  iin  BPid  (;,1 1^0, ,  railed  propionic  wid ;  whereas  the  Kuhstant* 
C'jUjO  (ncetone),  oUuiined  from  the  ahxjhol  with  the  lowwr  boiltug- 
point,  is  converted  into  carbon  dioxide  and  tux'tic  acid,  C,tl,0,: 


C,H,()  (propyl  akohtil  B.1*.    ft?*)- 


»r,H.<. 


(propionaldchycie)  • 


I 


— *C,1I,0,  propionic  acid. 

C,H,0  (iaopropyl  nicoliol  B.P.  81")— *C,H,0  (aoetone)— * 

— tCO,  +  C,H,0,  iicetio  acid. 

Propionic  acid  haii  the  constitution  Cn,-Cn,-C00n,  aiid 
acetone  (!If,-C<)-CH,,  aewill  he  eliovn  later.  It  will  be  observed 
that  the  normal  alcohol  idono  is  capable  of  forming  propionic 
acid,  becauao  the  production  ot  thia  aubstaiice  must  be  due  to  the 
repluceinunt  of  twp  hydrogou  atoms  by  ouo  oxygon  atom,  wtiich  in 
the  uoruial  alo«hol  can  only  givo  rise  to  n  compound  having  the 
structure  ii««ign<H]  to  prupiouicacid.  On  the  other  hand,  tlie  forma- 
tion of  a  giibstanre  having  the  stniotnre  of  acetone  by  removal 
of  two  hydrogen  atoniH  from  a  contponnd  C,H,0  id  only  poesihk- 
when  it  \vm  tiw  constitution  of  isopropyl  ulyohoi.  The  alcohol 
of  higher  boiling-point  must  therefore  have  the  normal  (tructure, 
and  that  boiling  at  the  lower  temperature  miiat  Ihi  i.topropyl  alcohol. 

Oxidation  alTords  a  general  method  for  diRttnguiithing  between 
primary  and  secondarj'  alcohols.  By  referring  to  the  formnlw 
given  in  44,  it  \»  men  tlmt  all  prinmr)*  alcohols  contain  the  group 
— 011,011,  which  !£  conrartod  by  oxidation   into  the  carboxyl- 

group  — ^^nif    ^^^   L'haructorititic    group    of    organic    acida; 

further,  all    secondary  alcohols    contain    the    group    II-C-OU, 

I 

I 

remoTil  of  the  two  hydrogen  atom:)  from  which  yields  the  group 
:  0,  charact«ri8tic  of  the  ketones,  the  homologuc«  of  acetone. 


BUTYL  ALCOHOLS. 


59 


Tht  OTtdation  of  a  primaty  and  of  a  recondary  alcohol  produftt* 
Ttsptctivfly  tin  u/mW  find  a  ketone  with  the  same  fiwwiftsr  of  carbon 
atoms  as  the  oriffina!  alvohot. 

A  farther  ilednction  mar  be  miule  from  the  facta  aboTc  otatod. 
It)  the  foiiver^iuii  of  normal  propyl  ivkohol  into  ]iri)|)iuiiic  hvlvX,  ob 
-well  as  of  jsopropvl  alcohol  ittto  acetone,  the  oxitlutiou  occiin 
at  the  csrbou  atom  which  \a  already  linked  to  oxygen.  This 
is  always  the  uue,  and  thn  gmierul  rule  niiiy  b«  stated  a«  follows. 
\VhtH  an  organic  couipimnd  is  xtihmittvd  to  oxiriativn,  the  >M(fJecvlf 
is  altaektd  at  th*  part  mhtch  already  contains  oxygen — that  in, 
where  OTidalion  has  alrradij  brgiiri. 

Kortuul  propvl  ulcoUul  it  obtaiuud  from  fuBcl  oil  by  fractiona- 
tion, and  is  a  colourletu  liquid  vith  an  ii^ooablo  odour.  It  » 
miftcible  with  water  in  all  ]>ropitrlioti8.  Isopropyl  alcohol  in  algo 
»  liquid;  it  does  not  occur  in  fuiiel  oil,  but  may  be  obtained  by  the 
redaction  of  acetone  (120  and  16S). 


Botyl  Alooholi. 

50.  Four  batyl  alcohols  are  known  (c/.  Table,  page  fil),  whioh 
ig  the  number  possible  Brconling  to  the  theory.  We  shall  here 
cotuiider  whether  these  theoretically  possible  formiil«!  are  really  in 
agreement  with  the  propertios  of  the  four  ieomcro.  Two  of  the 
alcohols,  thoHe  boiling  at  117°  and  107"  reepcctiTtly,  yield  on 
oxidation  ocide  with  tho  eame  number  of  carbon  atoms.  They 
must  therefore  have  the  etnictiiros  1  and  3  (Ibid.),  since  tho 
gronp  — CHjOH  is  present  in  both.  For  Teasons  which  will  be 
referral  to  later,  the  alcohol  boiling  at  117^  is  considered  to  have 
the  normal  Btmctnre  (1),  and  that  boiling  at  107°  the  Btruc- 
tnre  (3).  A  third  butyl  alcohol,  boiling  at  100°,  ie  conTerted  by 
oxidation  into  a  ketone  with  the  same  number  of  carbon  atoms, 
showing  that  it  must  be  a  sevumlury  alcohol  corresponding  to 
Btmcture  {'Z).  Lastly.  thi>  futirth  is  Holid  iit  ordinary  tom^teratures, 
mrltiogul  25-5'  and  boiling  tit  83".  Since  three  of  the  theoret- 
ically poesibli)  stnictural  forintilie  have  been  assigned  to  the  other 
tflomen,  thore  runaiiia  for  tht^  alcohol  only  the  fonrth,  which  ia 
that  of  a  tertiary  alcohol.  This  gtmctun?  for  the  alcohol  molting 
at  25-5^,  which  has  been  thus  arrived  at  by  elimination,  is  in  fact  in 
ttcooTilant-e  with  its  chemical  behaviniir.  On  oxidation,  for  exam- 
ple, it  yields  neither  an  acid  nor  a  ketone  with  four  carbon  atoms. 


* 


but  tho  molectilo  is  at  oiioe  split  up  into  anbstan<t«.<i  oontftininf;  a 
emallpr  number  ot  carbon  atoms.  Remembering  ttiat  ao  »l<;ohoI 
must  contain  the  group  ^fJlI^OTl  in  order  to  yipld  on  oxidatiou 
an  acid  with  the  same  nnmber  of  carbon  HtomB,  and  that  it  murt 

contain  »  group  U-t'-OH  in  order  to  produce  a  ketone  contain- 
ing the  same  number  of  carbon  atoms,  it  is  Dvidcnt  that  neither 
of  Itesfl  C8II  be  obtiilnod  from  a  tertiary  alcohol.  If  the  oxidation 
tuVes  pUici'  in  tliitt,  a»  in  every  other  «iae.  at  the  carbon  Htum  which 
in  iilraaJy  liukod  to  oxygen,  it  must  result,  in  ihu  duwimpoflition  of 
tho  mulvculo. 

What  hag  beon  said  alovo  holda  pjod  for  tertiary  alcohols  in 
gencrul,  eo  that  oxidation  afTor Js  a  mtians  of  didtin^iiihing  between 
primary,  eceondary,  and  tertiary  alcoholN.  The  expcrimcntnl 
proof  can  be  summed  up  as  follows. 

.■(  primiiri/  ah-oliol  ttiehh  on  oxidation  ««  arid  toith  the  $ama 
number  of  carhon  aiojm;  a  ftcondary  air-ohol  tfiehis  on  oxidatiou  a 
tetoHe  with  the  game  number  of  carbon  atoms;  while  oxidation  of  a 
tcrtiartf  (tlcohol  itl  onct  ipUts  up  tk«  tnoUcttle,  yieldin^f  compounds 
eontaimng  a  ai/ialJer  number  0/  carbon  aiams. 

Amyl  Alcohola. 

01.  The  alcohols  eoutaiuing  five  carbou  atoms  are  called  amgl 
alcoliola.  There  are  eight  possible  isomers,  and  all  are  known 
(cf.  Tabln,  pagp  51).  'I'licy  are  liquids  with  n  disagrt-^able  smell, 
likii  that  of  fusel  oil.  Isohutylrjirbinoi,  (Cn,),CH-CH,-CU,OH, 
is  the  principal  <H)ii.<ititueTit  of  fusel  oil  (47). 

One  of  these  alcohols,  secondury  bulylcarbinol,  affords  a  very 
r<>mar)ca)i1e  r*iiAo  nf  LHomerism.  Il  Uaa  been  shown  how  the 
arrangement  of  the  atoms  iii  a  molecule  accoutits  for  the  phe- 
nomenon "f  itiomcrism.  A  careful  study  of  thu  iiropcrties  of  a 
compound  iimkcH  it  possible  to  assign  to  it  a  atruetura]  formuLt, 
to  tho  exclusion  of  all  the  other  formuke  which  are  po^blc  for 
its  known  molecular  composition.  On  the  other  hand,  any  given 
stnieturol  formula  represents  only  one  oompounil,  sinc^  such 
a  formula  is  tho  expression  0/  a  very  tleliiiite  set  nf  pmpiprtics; 
whcu  these  are  utiliki;  for  two  oompuuuds,  tliis  must  be  indicated 
by  iheir  structural  formulat. 


MMYL  ALCOHOLS. 


6t 


Nevertlielos8,thpro«re  throe  ieomericarayl  nkohol!  which  li»7e 
fiecn  shown  by  careful  exnminatiou  to  havo  the  same  alnietural 
formula : 


n 

OH.OH. 


Thut  thcT  faftTo  this  coiietitution  in  proved  b;  the  fact  that  oa 
oxidation  they  yieltl  an  acid 


CH 
C,H.> 


C< 


u 

OOOH. 


the  atmcture  of  which  can  easily  bfi  provwl  by  aynthesia  (166). 

The  three  iwiiyl  iileoliols  with  tbis  cunNtitulioii  have  identical 
chfimieal  pruperlies;  their  phyitieal  con^tiintH  aru  also  altnoBt  all 
tbe  8Hm<.'.  but  one  of  the  latter  sltvcb  to  (lixliii^uish  them  from  one 
auothcr.  Whvii  n  beatii  of  pliuiu  pularinnl  ligtit  id  passed  through 
layers  of  thc«c  alcobole,  the  plauv  of  polarization  is  rotated  l>y  ono 
isomer  to  the  left,  aiul  by  the  other  to  the  riffht,  while  the  third 
iil<K>hol  prodiiceH  no  nit&tiun.  Tbo  first  two  are  said  to  be  optitally 
active  (27.  2). 

Since  the  differciico  between  uplii»lly  active  compounds  de- 
pends only  upon  a  pliyejcal  congtnnt,  wliilu  their  cheminil  propnr- 
tioa  urc  identical,  it  may  be  adk>.-d  whether  this  dillereiiou  i»  not 
a  purely  phy»iatl  one,  arising  from  dilTerf>nc«R  in  the  arranf^e- 
nient  of  the  nwiectihs,  eikOi  se  h  HUppoaed  to  exist  in  the  rase  of 
dimorphous  substances.  Tliere  are  two  reasons  opposed  to  this 
view. 

First,  diffcrcnrca  in  the  arrangement  o(  the  moleeuk's  can  only 

be  supposed  to  exist  in  the  cmo  of  idt'd  eubstancc?,  because  it  is 

oulr  in  these  that  the  moleculoi*  have  n  Eised  p^mtion  in  relation 

to  one  another.      It  iit  na^nmcd   tlint  the  moleirules  nf  liquids  and 

gmses  we  free  t«  movn;  but  tliey,  loo,  afford  cxainples  of  optical 

mctEvity.      In  the  case  of  lifjitidti  there  ia  Ktill  a  possibility  thut 

not    the    nmlernlea    thomselveK,    but    con glomcnit ions  of    them, 

mrtnxigcd  ta  a  doflaite  manner,  may  he  free  to  move.     Were  thus 

the  cttus©  of  optical  activity,  optirally  aetivo  liquids  when  oon- 

rertod  into  tlie  gnaemiR  atatn  Ethonhl,  their  vapour  densittea  lieing 

norninl,  produce  no  rotation  in  the  ]d»iie  of  polunziition.     That 

tht*y  nctunliy  do  prodnce  this  rotation  was  proved  by  Biot,  and 

later  br  Okiinez.     In  this  case  the  pbcuowcnou  cannot  bo  at- 


fit 


ORGANIC  CHEMISTRY. 


triliiitml  to  II  ilifforfiiivv  itt  tlii'  ummgement  of  tho  molecule*, 
tMiriiuiie  in  n  vniM>iir  of  normal  deneity  each  molecule  is  capable  of 
ibtltfiwndont  motion. 

S<H<4>nd,  tho  optical  activity  sliows  itatilf  in  deriTatirM  of  optic- 
ally miivit  nibstsitma. 

tinniw  il   folloWH  tliat  an  fjtptnnatioH  of  tAt  tvialton  of  t^ 
fttaup  of  polaritalion   in   thf  com  of  liquids  atid  of  tUsM^vtd  «iA-1 
tUncts  muft  he  rOn^M  for  in  ike  tirtteiMre  of  the  moUcuie*  tkttM- 
Srhta. 

Tit*  <nu>»lion  now  ariew  at  to  wluit  |>«caliarity  in  the  stracture 
of  tho  mol«cult>e  is  tli«  eaow  of  thi«  plicnomenoii.  The  foUovin^ 
onn>itli>nitiiiii8  will  «1iow  how  an  jnitight  may  be  obtained  Into  it 
Tho  IfiV'ivlatorjf  amifl  lUoAotr  the  cnn&titulioa  of  vUoh  has 
glran  abovo  m 

b  ocMiwtad  hy  th9  action  of  gaaeotu  hydnoclic  add   into  «ajil 
io4idf,  with  th«  rotutitatitin 

ClI     ^     U 

Thia  cMntMMind  m  »p4irftlly  ufin.     By  treating  it  vitli  naaccnt 
I  H}^KY»n.  tho  iodino  atom  b  rvplacvd  by  faTdtOfcn,  with  farwataon 

IN*. 


I 


If  Mnyl  iodtdr  U  nabjMtcd  to  the  ackaoo  of  ctinl  iodi^  is  tfae 
pntaM*  ft  todinm.  thcrr  nnJtt  a  kfptmmt, 

ftwl  Ikis  Mib««aac«  i»  ifUfittfy  ai*tm. 

tk«i  ikifi 

!«^.     U  tlw  Wtor  iWn  ai*  tw» 

to  U«  TCHUll  oai^Mi  •»«.  wkmM  « tW  < 

to  tiM  <«rUat  afeaMi  at*  at  < 


yAU  *7  HOFP'S  THEOttY  OP  STEREOISOMERISM. 


63 


ttiomii  or  groups;  ami  /it  has  litsiynated  a  carlimi  atom  so  Hnktd  an 
"  at^minetrk"  carbon  atom. 

It  Kaa  boeu  utaltid  above  that  tliero  are  threi>  ainyl  ulcohnlB 
having  the  same  conntitutionH]  formula^  of  vhich  oiic  in  c]oxtn>> 
r«tat«ry,  the  «t'i-<iiul  laivo-rotutory,  uiid  tho  lliird  optit-ally  iniictive. 
V\in:v.  siicrb  iKotofirtt  iilwuys  fsinL  in  L-uiuiiiotiun  with  mw  usymntnlric 
ciirbou  atom  iu  thv  luolcculc,  and  of  the  two  optiuully  active  »ub- 
«tBnecs  ouo  causes <.-XMCtly  the  same  amount  of  doxtPO-rotatinn  afl  the 
•other  of  lipro-rotation.  Van  't  HorKhaA  shown  th&t  tho  cxi^itcnce 
of  thU  ntimber  of  i$Mni<>r»  if:  a  neceasiiry  consequencp  of  the  oeciiir- 
renm  of  one  asymim-trir  mrbon  atom  in  11  molecule,  provi<Iecl 
'Certain  asHumptiunH  an<  matlc  n<phrdinj|;  llio  nrhitive  poHittoiiB  of 
the  atoms  in  epmx.  These  um  i\£  fulluwK.  Tho  tctniv»)enry  of  the 
cftrbon  atom  hiw  itg  orij^n  iii  four  points  of  Mttraction>  situatc-d  on 
its  oiit«r  gurfnt'e,  no  that  it  is  ahlc  to  link  it>!olf  tn  niomg  or  gronps 
of  aionm  in  font  dirorcions,  Coneerning  th^se  ciir«etion8  various 
UBUiuptions  ran  be  mad(?.  They  may.  for  example,  be  suppoeed 
to  lie  in  one  plane.  liut  thi^t  nnsumptinn  iu  untttnahle,  ar  will  be 
Been  by  considering  u  (Himpoiind  CU,(|,,  in  which  It  anil  Q  repre- 
sent any  diasiiuilaratomj  or  groups  of  atonu.  If  the  four  linkiDgs 
lie  in  one  phino,  suoh  a  componnd  may  bo  represented  by  Che 
fonuuln 

B  R 

Q— 0— Q,    or  by    Q— 0— K. 

Thtvte  arc  different,  beeauso  in  tho  firat  (.ikse  the  like  groups  are 
Mparated  from  one  another  by  tho  nutike,  while  in  the  second 
oue,  the  like  gronps  arc  adjapont  to  one  another.  It  folUtwK  fnini 
thia  that  in  general  two  ii^omers  mniit  exiKt  in  the  cnee  of  all  cam- 
pciitnds  C[t,<j,.  Kxperience  teaches  that  thix  U  not  the  cuee, 
beeaotK)  among  the  many  hniidrednof  cnniponndAof  this  typo  there 
is  no  imtance  known  of  the  occurrence  of  two  iwomerie  forms. 
Tbe  particular  aneumption  tliat  the  directions  of  all  four  linking^ 
lie  in  the  same  plsne  miii«t  there-foru  bo  ulmudoued,  being  at  rari- 
ancv  with  tlie  fact);. 

The  uiuxt  general  HXHumptiun  that  can  bu  made  in  regard  tu 
thoM  direciioiid  is  that  each  piiir  uf  tlieui  lies  in  the  same  plane. 


fi4 


OKG^MC  aiHMISTHY. 


They  are  tbeti  djgtriliiitecl  in  apH<>e  in  such  a  wiiy  that  if  the  cArhoD 
atom  be  iX'giirdLHi  an  aitiiatcd  ituidt-  an  irregtilar  tetr»lio<Ii'i)ii, 
the  directioRB  of  the  liiikiuga  will  be  toward  the  aaglei  of  the 

53.  We  shall  now  imcertiim  whether  tli  is  mode  of  n^prcseiitatie 
it)  in  Bticordaucc  with  the  facte.     If  tho  directions  uf  Xhv  linking^' 
make  diffcront  ungleii  with  one  Another,  thrre  still  remains  poedible 
n  difTerpncp  in  tho  stnictunil  nrrdnijoment  of  coiapoiiiidfl  rR.t),, 
booausr  it  in  jiint  as  easy  to  imapine  thai  the  gro»iM  It  «to  oontioolcicl 
witli  the  HnltingR  which  have  the  rnnHlIput  angle  between  them  M 
to  inia^np  tlmt  they  lire  j'mnpd  with  (.bosp  whinh  maki>  the  greBtea 
angle  with  miv  another.     In  the  case  of  cnnijwimde  CR,Q,  ihere^ 
ia,  however,  only  one  arratigoniout  possible  when  the  directions  of 
the  linkin^'d  nu'et  iit  equal  angles.     Tkin  i/t  the  ease  whra  lltf  r/ir&onj 
atom  1-1  rtrjardfd  us  Ifing  tfilt/aied  al  the  reu/re  u/  a  rfgular  fatir-- 
aitiNi  jitfiire  (Mrahettnut),  leith  iix  Unkinff$  diiiicled  toieardx  the 
anylfji  (Fig.  24).     By  putting  tliL-  ^jroups  K  and  Q  in  diffcn-nt 
puaitiuiie  in  two  aloiii  nuidi-lrt.  il  id  alwuys  pos- 
siblo  by  rotating  the  models  to  briQ^  them  into 
such  a  poHition  that  tho  Ii1<«  jrronps  coincide, 
.*h«winff  that  tho  two  forniH  are  identical. 

This  representation  of  the  direction  of  the 
Hukiiigs  i-xptain^  how  it  ib  that  tiieiv  are  no 
iBouK-ns  of  a  iromiiouud  CI{,y,.  In  llif  em^u  of 
componndH  ('-RI'QS,  which  contain  four  different  groups,  uud 
therefore  an  asyiumetrie  I'arboii  atom,  it  indjcateii  the  ixvi»il>ility 
•if  the  exititenoc'  of  two  isomerie  fnrnts.  It  JR  wen  from  Figii.  25 
snil  '^6  (uud  gtill  belter  from  models)  that  for  theitR  four  groups 
there  nn:'  pogsible  two  arrangements  which  cannot  lie  made  to  coiii- 
eide  willi  one  anoilier  in  auy  position,  althoagh  tlu^y  rcaenihle  one 
Another  in  the  eamc  way  that  an  objeet  rei^embles  its  reflection  in 

'Tlio  ranijuabi^uMiuu  of  wb«l  rollowswill  be  onniiderablj- fapllllalnl  It^tbri 
cnnmructlou  vf  eever&l  iDodole  ofctirbon  ntt>inB  witli  llioir  lloking*.  TLis 
omtlljT  "Innn  by  iriiilinc  out  a.  »|ilipr«  fnim  »  cnrk  lo  n-preseet  tbe  Mibun  mia 
the  llnlcliigw  being  n<iir«^t>nt(>ii  1i^  iiioiliiniti'lv  Ihink  imii  wires  abatit  Ivn  e«nt 
metres  ]oii|t>  tl"'  ciidn  or  wUkli  bavv  l>v?ii  lilwl  ti;  a  iiuiut,  Tb«M  wires  bi 
fis«il  in  the  cork  aplisre  in  llio  mitniipr  nlinn-ii  in  V'\g.  £4.  Tu  nbovr  the  Unking 
iif  file  atom*  or  groupn  <if  aiunis,  oork  spiiirps  of  different  cDloUn  are  (anti-ni^ct 
to  lLi«  hhIh  of  ibue  iidd  wlrot,  tlio  diBcrcnl  coloun  iadJcatiti^  Ibac  tlw  groups 
jm  diMiraifau-. 


TKTKAUKnUUM. 


V^N  'T  HOFF'S  THEORY  Oh'  STEREOISOMERISM, 


65 


iv  niirrttr.     A  figuro  uf  llik  kind  liao  iiu  ]iluii«  of  lij'mmotr^,  li«rift> 
the  luiiue  "  aii)'mmetric  carbuii  atom," 

Tliie  ttmkM  it  iio(<*ib]c  to  undiTtfUnd  liow  one  iaomor  in  jiut  m 
mucb  dt-'xtro-rotulory  m  tlic  otlivr  Iffivo-rotiitory  (62).  It.  is,  iu 
fact,  the  airaapcDK-jit  of  the  proiips  rolatirc  to  the  Jknymint'lric 
e«rt>on  mom  whioli  is  thp  am^  i»f  tlip  rotation  of  the  plaiiu  of 
poliirization.     If  the  ftrrajijrcmpnt  of  tiie  groups  iu  Fig.  25  pro- 


FiM.  av  Fi«.  SB. 

ABTJUIKTBIL'  C-ATOJCa. 

ducpD  dextpo-rouilioii,  then  the  iiivwrao  armiigoment  in  the  inomor 
Iu  Fig.  38  must  of  iipce*«ity  itiiiae  an  etjuiil  rotation,  but  in  »n 
opposite  direction. 

It  bns  been  staled  above  that  not  merely  two,  biit  three.  iHomerH 
occur  vhen  there  is  one  asymmetric  curboii  atoui  ]>reeent  in  tlie 
molfi'tile:  a  dextro-rotatory,  a  Itpvo-rotatory.  mid  an  optifullv 
iniM'tive  iitomer.  It  Ima  bpeu  proved  ihat  the  optieiilly  inactive 
snbstniioe  i«  compoei-d  of  ecpial  partK  of  the  dBXtro-rotatory  and  (if 
the  libvo-rotatory  rotcipotiiidd.  Siure  these  rotations  arii  uquiil  in 
amount,  ^ut  difTei*eut  in  direction,  their  eiim  huH  no  olTert  upon 
the  plauo  of  pulariziUiou. 

This  isomerism  in  spnce,  which  is  ejilletl  ilerfochemtea}  tt&tfttr- 
inn  or  ftcrwisouterisiti,  i»  not  indioAled  in  the  ordiimry  Btruclnral 
furraube,  which  arc  written  Iti  one  plane:  hence  the  apparent  cou- 
tnwlictioii  that  a  Miigle  etracturnl  formnia  may  reproaent  two 
different  compoiindt).  Van  't  IIoff'8  theory,  however,  supports 
tlu*  fundamental  principle  that  i»ontori»ni  ban  its  ori]i;ni  in  a 
diflcren'-t'  in  the  armiigement  "f  tlie  alome  tu  the  molecuk'. 

In  addition  to  die  exiilHiiaiion  of  opticfll  tsoineriBtn  wliicb  bra  juw 
\mto  given,  two  olliora  luicbt  bv  nuKKcaLeil,  Ijotb  of  whiob,  livwcver, 
can  be  xliown  lo  be  iitiletiable.  ll  iinght^  ftir  example,  be  8iippo«Ml 
tbnt  ihe  four  linking  of  the  carbon  alom  nrc  iiucquol  id  value;  iben 
a  OORipoiinil  saoli  a*  CPiQ  eould  exist  in  isomeric  (orniii.  Experience 
•hutiK  ItMit  ibia  in  uoL  llw  t-aae. 


66  ORGMNIC  CHEMISTRY. 

It  might  &Iao  be  suppoaeil  tli»L  tliit  plicnomenoti  is  iloe  U>  a 
dilTerenco  in  tlio  motion  of  t)i«  atoms  in  Ilie  toolecule.  If  it  w'ero  to, 
iMinieriaiii  could  no  l»iijc«r  exist  at  absoloto  aero.  sEnco  WoBiic  ni'itioti 
eeaus  nt  ilnii  iinint;  tints  «  fHllinji  lomprniiirn  xlioiild  cause  a  mnrked 
diminutioa  in  thu  dilTcrciit^c  Wlwwn  Itiu  oplicnl  iM]|[ier&.  Tttere  ia, 
however,  not  tlie  sligblcsl.  indionUan  of  stiaU  behaviour. 

Higher  Alcoholi.  C„JI^,,0. 

A4.  Their  propenifs  Imvc  alnmdy  l>ecn  mentioned  (45).  In 
additiun  may  bu  cited  cettfl  ntcolmf,  r^II„OlI.  obl»ineii  from 
spermacoti,  ftnd  m^ririfl  ttleahal,  C^^l^i.i\\,  oliLuiiiod  from  u-ax. 
Tlitf  number  of  i?omerg  of  these  higher  t'oinpoiiQds  po^eibU'  is 
very  gr«at.  while  the  niiniWr  actually  known  is  but  small.  Of 
the  liighcT  memhers  of  tlie  series,  only  the  normal  primary  coin- 
pouuds  are  knowu. 

Alcoholates. 

dS.  Alcoholtttes  nru  conipuuiidK  obiained  from  alcohols  by 
exchange  of  the  hydroxyl-hydrugeii  alum  fur  ruetiUa  (43).  The 
beat  known  are  xotlium  vtethylute  or  Methuzidt,  CH,'ONa,  and 
/KMiiiim  et/iylaie  or  rtlmxide,  C\Hi-ONu.  TheSf  are  both  white 
powders,  which  yield  cnstaliiut:  compuuuds  with  the  aleohol 
corroBponding  to  thorn.  Thoy  are  eaaily  soluble  in  the  alcohols, 
and,  as  will  b«  aeon  later,  are  fonatantty  used  in  synthosps.  Jt 
wftB  fomierly  mippoRod  that  the  addition  of  water  to  a  soliitioD  rif 
an  alcohoI»t«  conirerted  it  compli^tely  into  KaOlt,  and  liberated 
an  equivftlent  (tnaiitity  of  alcohol:  but  Lokrt  de  Brits  has 
shown  that  tliiA  in  only  partly  true,  and  thikt  an  equilibrium  is 
reached  in  th«  reaction : 

C.H.ONa  +  H,0;::^C,U.OH  -+-  N*«OH. 

(A  proof  of  tbie  will  bo  found  in  62.)  It  follows  that  a  solution 
of  sodium  hydroxide  in  alcohol  partly  doconipoeea  into  waUir  and 
liodium  aleoholate. 

Thv  ulvuliolic  »(>iulion  of  aadluin  othylaic,  which  is  usualljr  ohlnined 
by  dimolviiig  \i\w.m  at  Hoditim  In  absolute  ethyl  u1cu)kiI,  gmtlualljr  be- 
onmes  brown,  iti  conscquvncv  of  an  oxidation  procetts  (formalion  of 
flldehydc,  1U).  On  the  otlior  hand,  ihe  solution  of  Ewdtum  methyUte 
in  methyl  nlcotiol  reuiniti.s  iiiinliered,  for  whioli  rcaaon  it  Is  much  moi 
extensively  uawd  In  Myiiibt^cs  tbua  sodium  otliylata. 


ALEYL   HALIDES,    ESTEB8,    AND    ETHEKS. 


S6.  Muny  cumpoundH  conlaiiiing  a  liyJroxyl -group  fuc  knoi 
ID   inorganic  chcmiiiitry:    tbvy    urc    t^nlled    btuuiK,    iiud    rcwmblql 
«ne  ADotbiT  cloeoly  in  tlioir'propcHiee.     Thic  eiuiilority  iiukv  W 
ftttribnicfi  to  their  common  po«w««on  of  th©  group  OH,  which  is 
proiK-nt  in  th{>ir  n(|tiooa8  solution  as  An  iou. 

An  nqiicoTas  ewhition  of  alcohol  iloes  not  conclnct  an  electric 
current,  so  that  the  nicohol  is  not  ionized.  This  also  follows  from 
the  fact  that  such  a  sohition  is  not  alliftlinc,  and  therefore  contain*, 
no  Oll-iona.  The  question  accnnlinglj  ariaee  whether,  notwith- 
Btanding  this  lact,  the  slcoboU  posaeds  eomo  of  the  propeitiot 
of  baaos. 

The  acswer  to  this  is  iu  bo  far  afflruiative  that  they  are  able 
to  combine  with  acids,  with  elimination  of  water,  in  the  same  wajr 
as  basic  oomiKjunds: 


M-  OU 


AlonhQI 


Il]-R  =  M-K  +  110IL 

Eour 


AOid 


Those  mibslsnces,  which  ar«  comparable  with  the  salt*  of 
tnorganic  cbpniiatry,  are  oallod  cotupound  ethfrs  or  esters.  The 
tlifTprence  belweitu  the  nature  of  bases  and  that  of  alcohols  shows 
itself,  however,  iu  the  way  in  which  salts  are  formed,  which  is  quite 
onlilcB  that  in  which  esters  are  produced.  The  formation  of  a  salt 
from  an  acid  and  a  base  takes  place  iiiitantaneonsly;  it  is  a  reaction 
of  the  ioDB,  hecause  the  hydrog«n  iou  of  the  ai^'id  unites  with  the 
hydroxyl-ion  of  the  base  ("  Inorganic  Chemistry,"  86): 

(B  +  OH]  +  [H  +  Z'J  =  [B  +  Z']  +  H,0. 

BMf  A<M  8*U 

The  fcrraation  of  esters,  on  the  other  hand,  takes  place  very  slowly, 
especially  at  ordinary  tfiujwratures.  In  this  case  the  reaction 
is  between  the  non-tonizcd  alcohol  and  the  acid: 

R.OU  +  [11  +  Z]  =  K.Z  +  11,0. 

Alonltol  Acid  i:4l>r 

OeQcrally,  ruaetious  between  tons  take  place  infltaQtaneoaaly, 
those  hetwet-n  molemileB  slowly. 

Many  haaeti  can  lose  water,  with  fortoatlon  of  anhydrides  or 
oxides;  so  also  can  alcohols.     By  the  splitting  off  of  one  mole- 


68 


ORGANIC  CMBMISTRY. 


cule  of  water  from  ttro  moWulei)  of  nn  alcolioU  thort'  arc  formed 
compounds  with  the  geiiers]  formula  C,lI^.,^O^C,Uj„.j . 
called  ethers;  wll«ii  the  eliminatton  of  water  tukw  plurc  bv- 
twct-n  two  dilTeroDt  alcohok,  the  compouude  produced  have  the 


general    Tormula 
etften. 


C„H„.,-0-C„ 


II. 


and    arc    caLlod    mued 


Alk;l  Halidei. 

57.  The  alky]  halidcs  may  be  looked  npon  as  beinj;  the  Imloid 
acid  efltern  of  tli«  aloohola,  iw  is  sbowa  by  tJicir  fonimtion  from 
alcohol  and  6  haloid  acid : 


<'„H^.,mr 


m.\  =  C„H,„.,X  +  H,0. 


Ill  preimriiig  slkyl  balidea  by  this  method,  the  alcohol  ie 
Bitnriited  with  th«  dry  Imlogen  acid,  mid  Lheu  heated  iu  a  soaled 
tubfl  or  timler  a  ruflux-comlensor.  Tim  rMction  may  almi  be 
curried  uiit  by  lioutiiig  the  alcohol  with  eiil])hnrii::  a.i;id  and  sodium 
or  potOKsium  halidc: 

C,H.OH  +11,80.  +  KBr  =C,II,Br  +  KHSO.  +  H.O. 

Two  other  methods  of  formation  for  alkyl  Imlides  have  alruiviy 
been  aUuded  to  (30  aud  43);  those  are  more  fully  tri'sttcd  below. 

Action  of  Phoaphorvs  Jlalides  on  Alcuhuls. — ^These  sonie- 
timefl  ri"»ct  together  very  energetically.  In  pre|iariiig  alkyl 
bromidea  and  iodidca,  it  is  usual  to  employ  phoBphonis  with 
bromine  or  iodine  instead  of  tlitj  hromidti  or  iodide  of  pho»phoni8 
itself.  For  e.tamplo,  in  the  preparation  of  othyl  bromide,  amor- 
phous phosphorus  is  itddcd  to  strong  alcohol,  which  does  not  diR> 
solve  it.  Hmmine  is  then  fuhied  in  drope,  the  tempemlure  of  the 
liquid  being  kept  from  rising  by  tt  cooling-ngent.  i^oh  dmp  of 
bromine  unites  with  phosphonts  to  fonn  PBr, ,  which  reacts  .with 
the  alcohol,  prodacing  othyl  bromide: 

PBr,  +  3(',H,0H  =  H(OH),  +  3C,U,Br. 

The  aireful  addition  of  bromine  is  continued  until  n  quantity  has 
been  used  cnrresponding  lo  that  required  by  the  equiition.  The 
mixture  ix  then  uIIowmI  to  Ktiuid  fur  several  hours,  in  order  that 
the  naotion  may  be  h£  complete  ikt  jiOHuible,  the  ttnul  product  rt>n> 
asting  rAif/fy  uC  phoapboroua  acid  and  ethyl  bromide.  Since  the 
latter  boils  at  SS'j",  and  the  acid  is  not  voUtilo.  it  is  possible  to 


ALKrt  HMUDES. 


H 


Btpmte  thiMn  br  distillntton.  To  collect  this,  the  flssk  contnining 
the  mixturu  ik  immersed  in  h  water-bath  heated  above  the  t«niper»* 
tnn  raCQtione<). 

It  liiu  juat  bma  metitioBM  that  the  reaotjoti-misiurc  ooii»isU 
ctiicfly  of  pbotptiorous  actd  xncl  ethyl  bromide,  wlicranii  ilie  above 
equation  indwat««  that  ottln  tlieso  two  aubatanoes  are  formed.  Iteae- 
lions  iu  organic  oheml»try  are  xHdoin  riimutltatlro:  in  addiiion  to  ill* 
inafri  rtaettou  then  am,  in  the  grcKt  lUAJorlly  of  GA»<ut,  oho  or  mora 
MOOndar;  rcAcCioas.  Ttic  expIniiatioD  of  tfais  miui  \»  souglit  in  Un- 
ease with  wtiicb  orfpinjc  compoucicU  ntnier^decoDipoaition  and  react 
with  one  another.  Thaw  secondary  r«acuaiu  freqaonyy  %\^9  rue  ro 
tbe  formaiiun  of  darlE-coloured,  amorphous  itubiitnnueft  called  rtniim. 
h  \i  seldom  pCNHible  to  oblnin  any  individual  compound  oul  of  tbeiu. 
8otnetla)««,  hoverer,  tbokccontUry  praducu  of  a  r«a«tion  can  b« 
bolntcd.  as,  for  exanipio,  in  ihc  prongs  dracribcd  Abovt?,  in  wbicli  the 
«thf  I  ester  of  phcH|ihor>vuti  avid  bi  fomiMl  along  with  ethyl  bromide; 

PBr>  +  SC.I1.0U.=  P(OC.U.).  +  SHBr. 

^H  i%.  Action  of  Halogfui  on  Ht/drefurbons.—OnV'j  c\\\nT\Ae*  and 
^Hbretnidos  can  he  obtained  in  thin  way,  beoause  iodine  docs  not 
^^mct  nith  hydnx^arbona.  The  method  in  Heldom  nue^l  for  the 
r  preparation  of  alkvl  bulidca,  eiuce,  for  two  reamna,  mixtiirefl  of 
I  alkyl  halkle«  art<  obtained  which  are  Homotimnt  ver;  diflirult  to 
I  Mparatc;  whereas,  by  employing  the  other  mtthodi,  these  oom- 
^Lwandi  are  produced  withont  admixtare  of  Rimilar  eubctances. 
^"  One  of  these  winseJ  is,  thai  whenever  one  molecole  of  a  hrdro- 
carhon  C„1I^.,  is  broaght  into  contact  with  one  molecule  of 
chlorine  or  bromine,  the  rtoction  dova  not  take  place  merely  in 

rrdauce  with  the  equation 

but  that  at  the  eame  time  compoouds  C.Il^Cl,,  ^a^^^-i^i  <*<!-> 
are  formed,  a  portion  of  the  hydrocarbon  remaiiuDg  mucted  on. 

^^  Ii  U  pouible  lo  KTOid  tbs  fovnatioo  of  Ukm  higtier  BubnlintHrn- 

^f       prodact4  by  caBstug  ibe  balogBiia  iv  nact  witli  tbe  vapour  of  the  bml- 
I  iog  bydroeai  baiu. 

The   other  canae  in  that  the    halogen    replace*   hydrogen   tn 
different  ponttoni  in  the  molecole.     Thus,  chlorine  niacrta  with 
normal  pentaoe  to  form  aUnDltaneotuIy  primary  and  Mcondary 
alkfl  thloridee. 
CH,.CII,.CH,.CH,-Cn,a    a&d     CH,.CU,.CU,.CUa.CH^ 


70 


ORGAHIC  CHEMtSTRY. 


Tliia  can  be  proYcd  hjr  conrcrtiug  ihcao  cliloridi-s  into  the  corrc* 
'epoiicliug  itlcohols  and  oxidizttig  tlie  latter  (49). 

59.  I'lio  following:  t*blo  gives  some  of  the  physical  properlia 
of  the  oi/fifl  halid<.6. 


Cll. 

f.H, 

(■,11, 


Kuna. 


Elbyl 

«- Propyl 
CjM,     »-rritn,  biiljrl 
CtUii   n-Pritn,  Mu^rl 


rhiijtiilfl. 


BnlllnK-     Spcctllc 
point.      Onvlty. 


--  a8.:'0-9fl9(0*) 

12. a^  It). 918(8 
4fl.:i-  n.iii:;;o-| 

IS-      'O-W7(0-l 

lor   to.fioiLfl*) 


r 


HraRilda. 


Boiling- 
pMDt. 


Unntjr. 


4  5*1-788(0') 

S8-4-  l-4tW(ir) 


ledlde. 


potnc. 


71- 

lOi* 


I  ■  583(0') 
1.806(0*) 


48' 

102- y 

180° 
15B* 


ODeriflr 


l-»U(l4-> 

I.7»6lO-( 
l-543(0'> 
I-M3t0*> 


It  will  T«  noticed  fiuik*Mil5  tTio  lower  ohloridea  and  methyl 
bmmiOu  ure  gunL-oiis  at  t&d  onlinary  tDaipemtttri),  man  of  the 
otJierii  buiDg  1i(|ui(](i,  und  the  lilgheist  inumbers  solids.  The  specific 
pruvitii's  of  thf  cliioridL-a  arc  in  ull  cusch  loss  than  3.  and  dimiiiiith 
as  tlif  MimitiiT  uf  nirbou  iLtuiue  iiirrwwc*.  TIic  ap«*ific  gnivities 
of  the  bromides  and  iodides  are  considerably  jrrvHter  than  V  for  the 
lowrKt  memhero,  iiUhotij;h  thoj*  also  diminiiih  with  iiioreoM  in 
the  niimliep  of  the  carhoii  atoms,  ho  tlmt  the  hij^ht^ut  tprm«  of  tho 
hotnnlognns  Beries  :ire  djioclltcallv  lighter  than  vater.  They  are  all 
\*ry  slightly  soluble  in  w«ttT,  Init  dlitsolvc  reutUly  in  many  nrgniiic 
eolvGiitf.     The  lowest  nieuiUem  hiivu  ii  pleuHaut  ethereal  odour. 

Clifmical  I'ruperiits. — In  their  Action  upon  silver  lutnite  the 
alkvl  h«lide«  are  very  different  from  the  halidoa  of  the  metala. 
In  iiqiiivnip  or  ideoholio  Holution  the  latter  nt  onee  yield  a  precipi- 
tate of  silver  halide,  the  reaction  being  (jnantitative.  On  the 
other  hand,  silver  nitrate  either  does  not  preripitate  eilvcr  halido 
from  a  solution  of  the  alkyl  hulide»,  or  the  rearUnn  only  take» 
place  slowly.  The  explunatiun  ie  the  same  as.  that  given  in  68. 
that  in  the  Qret  case  the  notion  is  one  between  the  ions,  and  in 
tht'  uee-ond  Iwtween  the  molccnlea.  This  proves  that  there  are 
eitlior  no  halogen  ionx  present  in  an  alkyl  hnlido  Golntion,  or  at 
least  that  their  miniher  ia  very  small. 

The  halogen  componndfl  ran  Iw  converted  into  one  auoCher;  for 
example,  idkyl  iodides  run  he  obtained  by  heating  the  correspond^ 
tng  ofalorides  vith  KI  or  Cal,.  These  reactions  are  often  incom- 
plete. 


ESTERS.  J» 

Tlic  alkyl  iodides  are  chiufiy  uiwd  fur  introduciug  alkjl-gronpe 
ifit«  organic  comfioiiadii. 

Alkyl  fluonilcs  are  atso  known,  nDtt  iu«  inorv  vol&tile  ttiAti  th«  cor- 
nspoiidiDg  chlorine  ooinpnands.  Tltejr  oro  obtuncil  bjtbvkction  of 
ftiUer  fluorid«  on  an  allcyl  iodide,  and  in  other  whjb. 

Etten  «f  Other  Uineral  Acidi. 

80.  Efltere  of  a  great  numbur  ul  miiienil  acid«  are  known.    The 
gvneral  methods  for  tbutr  prt-paration  ar«  a^  follows: 

1.  Bv  tlie  action  of  tbe  ai^id  on  absolute  alcohol: 

C,H,-  pH4-H]0K0,  =  H,0  +  C,H,.ONO^ 

AkMhiH  MUic  lU-U  KtLjl  oHrue 

2.  Bj  th«  action  of  an  alkyl  halide  on  n  silver  wiH: 


SQ.jAg,  +  lil]C,iI,  =  SO.^C.U,),  +2AgI. 

Ellijrl  alllplialr 

3.  Bj  the  action  of  mineral   ncid  chlorides  on  alcohols  or 
■l«dta1at«g: 

The  acid  eatera  of  nilplturio  acid,  which  are  nsuall;  called 

aSkyl-sulphuric  acids,  are  of   soiu»   ini  porta  nee.       Ethtilmilphvrie 

aeiil,  or  ethgl  hydrotftn  twtphaie,  C,HjO-SOj-OH,  is  ol>tain("d  bv 

mixinfr  alcohol  with  conccntnitcd    Bulphiiric  siiid.     The   forma- 

Ijoii  of   thin  roaipound  18  noTor  quantitative,  owing  to  the  fact 

that    an    cqiiilibriuni    is   rwiched    in    the    reaction   (69).      Tlie 

ethylenlphuric  acid    is  separated    from   the  excess  of  Kulphurio 

wid  hy  moans  of  thp  barium  (or  the  strontium  or  calcium)  ealtB 

of  the  alkyl-Hiilphiirtc  aridfl.  these  compmindB  being  eaeilv  soluble 

in  water,  while  tlie  enlphativt  ttri.-  iimoluble,  or  nearly  so.     It  is 

only  neoepsary  to  nentrulize  the  mixtun!  of  sulphnric  acid  and 

alkyl -aulphnrie   acid  with  barinm  rnrbonate,  the-prctduct  being 

ha 
a  solntion  of  barium  othyl  sulphate,  p  fj  >  SO,.     The  free  cthyl- 

solphuric  add  is  then  obtained  by  tho  addition  of  the  calciilnted 
qnantity  of  sulphnric  acid  to  this  solntiou.  At  ordinary  tempera- 
tnrcw  it  ui  an  odourless,  oily,  stronply  ncid  liquid.  miBeible  with 
wat«r  in  all  proportions;    the  aqueous  solution  decumposos  into 


7a 


OKCANtC  CHEMISTRY. 


eulpliQiic  acid  and  alcohol,  elowlj  nt  the  ordioar;  tcmpcruturc,  but 
quickly  wlion  heated  to  the  boiling-point. 

Tlio  iMiriuR]  s&lu  of  tbo  Hmylsul|>1iuric  Aoids,  obtalued  from  tbo 
Mtij'l  alooliols  Hod  siilpharic  luiid.  have  diffcrrnt  solubilitiofi  in  w«tcr, 
imd  can  be  partially  sepanUed  by  fractional  orysUillizatiou.  Bf  tiiis 
iscaiia  Pastbdh  wu  Rl)Ie  U)  aeptirate  tbe  optically  a«iive  adi}'  alcohol 

from  Uobutylcnrblnol,   ^|||>CH-CK,-OH,.OH,  both  of   which  nn> 

preacnt  iti  thti  mixture  of  amy)  nicoliola  boiling  at  ISI'-IUS*  obtajiit-d 
by  lli«  frnctiuual  dislillnlioti  of  fusel  vil.  Isobntylcarblnol  is  tlii>  cbirf 
eonttitueDt  of  the  tnisture  of  amyl  nlcohots  boiliug  at  this  temperature. 

Ethylgulphiiric  npid  forms  well  cryKtnlliwd  wilts;  its  pota«8iuni 
salt  ie  need  in  the  pr^piiration  of  ethyl  cnnipmindR.  For  example, 
ethirl  bromidfl  n  reiulily  prepared  liy  tlio  dry  distUUition  of  u  mix* 
tlire  of  potasfiiiim  hrnmido  and  ]iotai»iuin  ethyl  HuIphHte; 

K0-SQ,-O|C,U74^BiiK  =  K.OSO,-OK  -h  C.H^Br. 

■"OIBHl Otllj)  •  PlItHMlUIII  Etltrl 

•iilplikili  iriilphaM  broiriiilf 

When  frwj  ethylfltilphurie  acid  is  heated,  the  neutral  uthyl  eater 
of  Bulphuric  acid  and  free  sulphuric  acid  Hre  formed: 

OC.H.   ,    o»      OH  ^.»      OH  .   „,.    ,OC.H 


SO. 


<oif  * + '*«.<oc.u, = *'**.<0H  +  s«><oc;h;- 


Estera  of  the  fallowing  minernl  acidaarc  also  known:  hypochloroas 
acid,  poiNihlorio  acid,  sulphurous  acid,  <iiilp)iurio  acid,  hypo&itroua 
acid,  nitrons  acid,  nitric  acid,  pboitpburous  acid,  liypoptiusplionc  acid, 
pbosphoric  acid,  aracnloug  acid,  arsenic  acid,  boric  acid,  and  silicio 

aoid. 

SaponiflcatioQ. 

61.  When  esters  are  hoited  with  dilute  anids  or  alkalis,  or 
when  heitted  to  n  high  temperature  with  wat«r,  they  decompose 
into  alcohol  and  acid,  titkin^  up  one  molecule  of  water.  This 
proceaii  is  cjJIed  "  BupouiHcation,"  hecauau  it  reficmbles  the  prep- 
amtion  or  Hoa]i  from  alkali  and  fiit  (91).  The  formation  of  an 
Mter  iioui  an  aloohol  and  an  aeid  is  called  eitertficaticn. 

Etheri. 
63.  The  eonetitutiou  of  these  compounds,  which  are  isomerio 
with  the  alcohols,  is  proxed  by  Wiluamsos's  Bynthesiii,  the  action 
of  ftD  ttlcoholutu  on  an  alkyl  hiitiile: 

C.H^,.01KmJ  .C„,H^..  =  C.H„„.O.C,H^.,  +  N»I. 


BTHEHS. 


73 


This  synthesis  affottlB  confu-mation  of  tho  conBtitutJon  of  the 
alcobolates  indicated  in  43,  tluit  the  metal  occupies  the  place  of 
the  hrdroxyl-hydrogon.  Fur.  supposing  this  were  not  the  cuast 
and  tliat  the  metal  had  ropIftL-tnl  u  liydrogon  atom  dirt^ctly  linked 
tu  varbon,  then  sodintn  mcthylato,  for  example,  would  hare  the 
formula  yaXHj-OH;  this  would  jiold  propyl  alcohol  when 
treat«d  with  ethyl  iodide: 

CH.OH  =  C,H,.CH,OH  +  Nal. 

TbiB  reaction  does  not  take  plftc«.  There  is  prodnood  inetoad 
methylethyl  ether,  whirh  has  the  empiric-al  foniii.ila  of  an  alcohol, 
but  none  of  its  properties. 

WitxiAMiv>.v'9  flyntb<?8iA  is  also  pos^iblo  when  the  alroholate  is  dis- 
solved in  dilute  alcohol  (JiOJ),  Though  «o  much  waler  is  praspnt,  the 
T«actii>ii  is  aliiicitti  a  qiiantiuttivconc,  from  which  it  follows  tltat  the 
greater  pnrt  of  the  sodium  alcoholAte  raiut  ba  pro«ent  as  such,  and 
tbtrefore  is  aot  dccomixued  by  tho  water  into  alcohol  and  nodium 
hfdrate  (55),  becaufie  in  (hat  caB«  tfa«  (onnaijon  of  ths  ether  would 
neceuarilj  be  prevenud. 

63.  The  beat  known  compound  of  the  honiologoas  Beriea  of 
ethers  ig  the  diethyl  ether,  0^11^-0-0,11^.  whieh  ia  usually  called 
tther.  This  compouud  i»  maiiufuctured.  and  uIho  prepared  in  the 
laboratory,  from  aulphuric  acid  and  ethyl  alcohol.  For  thia  pur- 
pose a  mixture  of  five  parta  of  alcohol  (90*)  *  ia  heated  with  nine 
pAita  of  concentrated  itnlphnrie  acid  at  laO'-UO*.  Kthcr  and 
water  ditilil  over,  and  as  iionn  an  diRtillation  hoa  eominenced, 
alcohol  i«  allowed  to  llnw  into  the  di.>itilling-f1nsk  at  such  a  rate  as 
to  keep  the  volume  of  liquid  in  it  c-onstant.  Kther  pa«t)e4  con- 
tinually orcr,  but  after  about  Rtx  times  a«  much  alcohol  hag  been 
odd*^  as  waa  in  the  fimt  inntance  mijtC'd  with  Ihe  sulphuric  a<rid, 
the  dietillate  Iwcomes  richer  and  richer  in  alcohol,  until  finally 
the  fonnation  of  otlior  8to]i8  altogether. 

The  oxplanation  of  this  process  is  as  follows.  Tho  alcohol  and 
salpbnric  acid  in  the  first  inittance  form  ethylmilphnric  acid  (60). 


*Meili5laiMl  *plrit  ta»,j  be  snlntUaied  for  pun  splrEt,  the  product  belof 
aallad  "  iDeUirUtnd  otlm-"— Tbakujitok. 


74 


ORGANIC  CHEh4ISTRY. 


When  ethylmiliiliurio  Rcid  in  honted  with  wntor,  it  u  aaponified, 
with  7«generntioii  of  the  acid  and  alcolio]: 


C,U,   O.SO,II  -h  H(OH  =  G,H,.OH  +  H,80.. 

When,  however,  iiistefid  of  water,  ethyl  fllcohrtl  reacts  on  ethyl- 
salphnric  acid,  ether  and  sulphuric  ftcid  are  formed  in  an  exactly 
analogous  manndr: 


The  production  of  other  depends  apon  tlio  fortnatioii  of  cthyUul- 
phuric  acid,  and  eiibseiineut  decomposition  of  this  compouud  lulo 
ethyl  ether  and  sulphuric  acid  by  the  addition  of  more  alcohol. 
Since  th«  aulphuric  acid  is  a^raia  formed  (regenerated)  in  thia 
reaction,  it  yiulds  a  Tretih  qiuintity  of  etbyliulphunc  acid,  bo  that 
the  ])rocc«»!  is  a  coiitinuouH  one.  This  would  lead  to  the  expecta- 
tion that  B  smalt  (juuritity  of  milpliuric  lu-id  wuiild  W  alile  to  con- 
rorl  an  iiiilimitinJ  smoiint  of  alcohol  into  other,  but  this  \b  not 
lioruc  out  by  i-xpericacc.  The  explanation  i«  that  bi  the  forma- 
tion of  ethylsulphuric  acid  from  alcohol  and  Btilphuric  acid,  water 
ifl  formed  as  a  by-prcxluct: 

C.H,iOgirHSO,H  =  C,H,.SO,H  +  E,0. 

Thifl  water  partly  distiln  over  along  with  tho  ether,  bnt  partly 
remains  behind  in  th«  flo&k,  decomposing  thu  ethylsulphuric  add, 
as  soon  as  it  is  formed,  into  alcohol  and  tiulphuric  ucid.  When 
the  amount  of  waU>r  in  tho  rotLctiou-mixture  exceeds  a  <^«rLain 
limit,  it  provonts  ihu  fonnariou  of  ethylsulpliiiric  acid  altogolher, 
and  ill  tlii«  way  puts  an  end  to  the  production  of  other. 

When  another  aleoliol  is  allowed  to  flow  into  the  original 
mixture  instead  of  ethyl  alcohol,  shortly  before  the  diatillation 
begins,  a  mixed  ether  ie  obtained: 

CA1^0«H  +  HtO-C,H..=C,U,-0-C,H..  +  II^SO.. 

This  is  a  proof  that  the  formation  of  ether  really  tak«s  i>Iaee  in 
the  two  atagi-a  mentioned  above. 

Thv  crude  ether  oblainiMl  in  this  manDcr  coolains  water,  alcobol, 
and  sni:kl]  ((uuiitititw  nf  siitpliiii-  diuxiiio.  It  is  left  iu  contact  nitb 
quicklime  fot-  sevoml  days,  llic  wAior.  Kiilphar  dioxide,  and  part  of  th« 
aloohut  being  thus  rcmDved ;  it  is  then  distilled  from  a  vtMr-bMta 


ETHERS. 


75 


I 


bMlAi  to  ubimt  SA'.  To  remore  lli«  small  <itiatniiy  of  alcohol  rcmatii- 
lag.  it  i«  sli»kcn  up  scTenil  times  with  small  Tolnmwof  nitXer,  and  the 
wat«r  niu  oil.  The  ether  is  iwfwraipd  from  iJiMtolveil  wal«r  hjr  dl^ 
tilUition,  6nl  orer  calcium  chloride  nod  llnitUy  over  lodiuin. 

Diolliyl  ether  n  a  oolonrlees,  rery  mobile  Hi^uid,  boiling  :it 
aS'l",  and  soliiliryiiignt  — IlS-l".  It  hu^an  a^ewible  otlour:  pro- 
longed breathing  of  it  [irodiicet)  uiti^oniurioueinusii,  followv*]  by  but 
filigbtly  disagrtivablo  coiiacqaoncoa  on  nwakoiiiug.  Ktbcr  U  tiion?- 
for«  useii  in  «urgcryag  nii  atitosthotic.  It  i»  slightly  soluble  in 
water,  oiio  volume  dissolving  in  n*l  volntnes  of  watvr  nt  35°;  on 
the  otlwr  hand,  wnter  dis^ulveg  slightly  in  ether  (2j(  by  vohimi'  at 
12°).  On  account  of  its  low  hoiling-jioint,  ether  is  very  volatile, 
and  aa  it«  Tapoitr  is  highly  cnmbaetible,  burning  with  a  luminous 
lliiuiv,  and  producing  un  exploeivo  mixture  with  uir,  it  is  a  subatauoe 
wbtdi  mnat  be  very  carefully  handlGtl.  IntoDiio  cold  ie  prodncod 
l)y  its  evaporation,  the  cuteido  of  a  flaek  coutjiiniug  it  b4H.'ommg 
cxMtted  with  iec  whon  thv  t>vft[iorntiuu  uf  tho  ether  is  proniotud  bj 
tfa»  iutroductioii  of  a  rapid  atre-iim  of  air. 

In  the  laboratory,  ether  ia  an  invaluable  solvent  and  cryatullis- 
itif^-iuediunL  for  many  compounds,  iu  addition  to  its  uite  for  ex- 
traotuig  aqneoRs  aolutions  (St4).  It  is  also  of  great  utility  in  many 
niaii  u  ra<>tii  rtn  g-pmnessoe. 

Homol<^es. 

64.  Dimethijl  rihti\  C'II,-0-C'lIj,  is  nMained  in  the  same  vay 
a«  ordinary  etbor,  and  is  a  ga«  liqHcfyiug  at  —  2U\  Tlie  hi^or 
horaologucs  are  liquids,  the  highest  lioiug  solid  crygtalline  stlb- 
stanccd:  nil  Iinvo  a  iipccific  gravity  considerably  Ie«e  than  1,  the 
majority  Iwtween  O-T'  and  0-fi. 

The  ethers  art-  comparatively  ulablti  towards  rhemical  reagents. 
Dilute  acids,  iilkiilifi.  and  plioHphoniH  jientjirhloride  have  uo  action 
on  them  at  ordinary  tempc-nilureii;  sodium  it?  tiuablo  to  displace 
nny  of  their  hydrogen.  When,  however,  they  are  heated  with 
haloid  acids,  halogen  componiidtj  arc  fonii(>d.  In  thin  wav 
gaseous  hytlriodic  acid,  when  j>iL^S(td  iittu  an  elhv<r  at  tbi>  ordinary 
teiujieralure,  prodtic-es  alrohol  ami  alkyl  iodide: 


76  ORGANIC   CHEMISTRY. 

at  higher  temperatures  water  and  alkyl  iodide  are  formed ; 


C„H,„,,0|.C„H,„  ,  +  |3H 


I  =  C3,n„I+C„H^„I  +  H,0. 


Isomermn. — This  may  be  cauBed,  aa  in  the  case  of  the  alcohols, 
by  branching  of  the  carbon  chains,  by  tbe  alteration  of  the  position 
of  the  oxygen  atom  in  the  molecule,  or  by  both  causes  simiU- 
timeoualy.  y 


ALKYL-RAIIICLES  LINKED   TO    SULPHUE. 


65.  TIiOM  elumeuU  wbiuh  arc  grougicnl  !ii  the  same  column  of 
tTip  periodic  Bystem  ("  Iiiorgatiit:  Cliuuiwlnf,"  311-831)  yield 
similar  (.■oiapouiidzt.  a  fact  tmccablo  to  tboir  liuviii^  cfjuul  vulviiciutt; 
they  furtlitfr  rcKi-ni))Iti  one  another  in  tJioir  chemic»I  properties. 
Expcrienco  lins  eJio^v-n  thiit  orgfinic  compounda  contaiiiiu?  elements 
of  such  n  group  display  the  properties  of  their  inorgiiiii<?  unnlnguea 
in  every  rnriet;  of  aimilurity  nnd  diEuimilnritj,  th^ir  points  uf 
reMmblaiics  anj  of  flifTerenfo  being  sometirae-i  ctwh  iiu)r»  uiarXvcl. 
than  those  of  the  itior^iic  compounds.  A  oomparinnn  of  tlio 
oxygon  compounde,  which  huvo  been  di-alt  with  up  to  tUis  poiot, 
with  the  sulphur  compound*  of  eimUnr  etmcturo,  vill  servo  m  on 
example  of  this. 

Tlie  alcobolg  and  cthora  may  be  regBTrled  iw  being  derived  ' 
wnter  by  ibe  re]>lac*'ment  of  one  or  botli  nf  its  liydrngen  at 
alkyl.     Tbo  corresponding  snlplmr  romponnds  arp  dpriv. 
■same  way  from  sulphnretted  hydrogen;  they  are  reprt-" 


c„H,„.,.sn 


and     C„n^.,.S-C, 


Tho  firat  are  called  mertutptanf,  and  the  si 

Tbe  resemblain'w  of  tboM)  conip"""  ' 
ii  chiefly  notirt-able  In  their  mo' 
huteod  of  KOU  reacts  with 
formed : 

1.V 


ers. 
aols  and  ethers 
-alion,  for  if  KSII 
.iklidv,    a  murcuptsn   is 


1U,-SH+RX. 


The  property  poweKJ 
atom  iti  the  luoU'ciili' 
ToptacTJiblc  by  metals 
rGBAonnblc  to  etipp< 
irom  all  the  others, 
atom*  being  linlceil ! 

Jntit  lu  tbe  «!' 
olrobolates,  so  tli. 
compound!)  of  the  i 


•iV-obols,  of  having  one  hvdrogen 

ibliud  from  all  tbe  others  in  being 

luud  in  nicrt-'aplauti.     It  in  therefore 

:■  c  bydro(,'vu  atom,  thus  diKtinguishod 

.  to  flulpimr,  the  rert  of  thv  hydrogen 

dunned  by  tfie  action  of  alkyl  halldee  on 
rs  ure  obtuincd  by  treating  tbe  metallic 
fius,  tho  mercuptide^,  with  alkyl  halideo: 


an^M-sj^     ;  n^M  =  c.u.,...s.c„ii,„,,  4-  nuI. 


7? 


ORGMMC  CHEMISTRY. 

Water  is  a  uontral  compound,  and  sulphurcttod  hydrogen  is  a 
u'ouk  add;  oorreapouding  tu  thlo,  ulvohol  does  not  form  &lcohol&te« 
with  the  hasen  of  the  huavy  motaU,  while  mi>n>jiptanii  ytold  luercap- 
tides  u-ith  ihtm.  An  ulcubol  sucli  as  uniy]  alcohol,  which  is  soluhli* 
with  difliculty  in  water,  dot-it  not  dissolve  in  alkalis;  but  the 
mercaptan«,  which  nro  all  iniM>luhlu  in  wutur.  arc  on  the  other  hand 
easily  solubW  iu  alkalis,  with  formation  of  murcaptidoB.  Tbey 
tbereforu  pussL>8S  au  avid  viharautor. 


UtrcaptauB. 

66.  In  addition  to  the  methods  of  formation  already  mentioned, 
mercaptonH  con  bo  obtained  by  the  action  of  phonphorus  pento- 
enlpbidc  upon  alcoboU: 

5C,H,„ . ,  ■  OH  +  P,S,  ^  5C.H„„  -  SH ; 

>'r  by  distilling  a  solution  of  potassium  alkyl  auljdiato  with  potas< 
'vdrogen  sulphide: 

u,'Q-8o,K  +  g^8n  =  c,n,su  +  K.ao,. 

They  ar.  almost  ineobible  in  water,  with  boiling-point* 

markedly  lowv..  i  those  of  the  corresponding  ulcohotfi.  Thng, 
meihgl  menafitaH  ■*'\-fl.t  (i",  methyl  alcohol  at  88°.  They  are 
chnrncteriaod  by  tbu  ,  — loA^ion  of  au  excMdhifflif  diuiffreeablt  snitU, 
which  thpy  havu  in  coniiat      ■"i"'i  almost  all  volatile  sulphnr  com- 


pounds.      Our  organs  of  m  :  ' 

and  can  detect  the  morost  tr 
slight  nti  to  bo  qutt«  unre^ogniz*, 
Many  metallic  compounds  of 
of  them  in  a  well  eryetaliized  fo, 
fnniiiib  an  exaniplo  of  thoso  bodios, 
of  nien-ajjtaiu  on  mtfrcnric  oxide,  k 
pounds  is  dorirod  (by  shortening  eorp 


very  sensilivt'  to  mercaptans, 

them,  even  when  they  are  so 

rrbeinical  means. 

■n-aptiins  are  known,  some 

I'ho  morcuTT  meroaptidos 

are  produuod  by  the  action 

i<     the  name  of  these  oom- 

ercurio  aptum  to  w«r- 


caplan).  Many  of  the  other  hemy  t.h  ,'.i.  such  as  lead,  cnpper, 
and  biamoth,  yield  mercaptidos;  tbe  1  "  ^"i  pounds  hare  a  yellow- 
colour.  The  tniTcaptun  id  sot  froo  Irurti  idl  niercapttdea  by  thd 
addition  of  mineral  acids. 


iERS  AND  SULPHOHK  ACIDS. 


7^ 


Ttiio«tb«n, 

87.  In  addition  to  the  methoiln  given  In  65  for  the  preparMioa  of 
tboM  coatpouiids,  tbc  action  of  polnssium  sulpliidd,  Ki^S,  upon  the 
siiltB  of  alkyl-sulphiirio  icids  laajr  be  employed  : 


'>SO,  ftr*  formed  by  tba  oxidation  of 


acH.[o^.K  ■¥  K.  [3  =  (C,nt>.a  +  2K.8O4. 

folaaaluRi 
Plliyl  lulpliato 

The  Uiioottiors  arc  nDuLral  compounds  nfth  an  oxcoedlngty  offan- 
ftire  smelL  They  are  liquids  insoluble  in  wal«r,  and  yield  double  com- 
poDods  with  melallio  ttaita,  e.g.  ((J,Ili),S-Hj;;C'li, 

The  roercnplans  rc-jioinbic  sulphnrQtIcd  hydrogen  tn  boing  slotrly 
oxidiiod  by  C'unlact  witb  iiir,  whcrvby  tb«y  aro  courcrted  into  disul- 
plitdus;  for  exft&i[il«,  dlothyl  dlsuljiliide, 

U«relh«  bydrogfn  nhicli  is  linked  lo^ulphnr  iSTemovedbyoiidation, 
so  that  the  disulpLiidcs  liaro  (ho  constitution  giren  above,  tlie  proof 
of  this  being  tb.it  Ibey  aro  ^<o  oUaiued  by  beating  potassium  elbyl 
sulpbate  with  K,&.. 

Nuinernnft  compoandx  containing  oxygon  and  milpliDF  occur  among 
inorganic  bodies:  tubstanoce  of  this  kind  are  nliolcnonn  inorganic 
clieiDisIry. 

The  suiptioxidtM,  H"!!'"^': 

tbioelhers  with  nitric  acid.  Their  conititiitlon  Is  Indicated  by  th<> 
fact  llmt  tbcy  are  very  uiwily  reduced  to  thiocthcn.  If  the  oxygen 
vera  linked  lo  carbon,  Khev  wouid  not  behave  in  this  manner,  becanse 
uvitber  aloobc^s  nor  etlien  lose  their  oxygen  by  gentle  reduclion. 

I^    It 

The  »uiphotut  are  compounds  irith  the  constitution  ,,"1]  " ' ' > SOa, 

■sahown  in  U,  Thty  ai-e  formed  by  strongly  oxidizing  the  tbi««tb«rs, 
and  alto  by  tho  oxidation  of  sulpbotiden.  Naacent  faydrogeo  is 
UBftUe  to  effect  their  reduction. 

Solphonic  Acidi. 

M.  The  nUphnnic  acids  rosalt  wlacu  niercaptaRfl  nndetgo  vigorous 
oridalion  (with  nitric  »ictd>.  They  hare  Ilii-  f<inmila  0«lf,n.-  -SO.ll. 
Tbo  alkyl'group  rcnutins  intaot  during  this  oxidaUon,  for  tho  salt«  of 
tfacM  salphonic  acids  are  alao  formed  when  an  alley]  iodide  reacts  with 
»  DU]phit«  ; 

CiU.rrn^so.K  =  ki  +  cd.so.k. 

Sinoo  the  Bulphtir  In  mervAptana  is  direetly  linked  to  carbon,  the 
•ame.botds  good  for  (ho  stilphonic  acids.     Thla  ia  furlbcr  proTcd  by 


8o 


ORGANIC  CHEMJSTRV. 


tb«  fnct  that  lh«  latt«r  ytftld  mereaptaas  on  redoetion.    The  itrnetim 
of  ethylaul  phonic  acid  it  tbereforv 

CH,.cn..so,H. 

The  group  SOtH  miul  eonuin  a  liydrosjl-group.  bccaiiM  PCI* 
7l«Id8Witba  sulplionic  acid  a  compound  CBlIn,i-SO*Cl,  from  whicb 
tbe  sulpbontc  acid  uay  be  reKfiueraied  by  t\w  nctioD  o(  water.  Tba 
»tro«tureof  the  compound  i«  lhcivforoCIl.CH.-SO,-OlI,  wjuch  Icayea 
it  Atill  doubtful  whether  tbo  group  SOi  contained  in  it  bas  the  stroctnre 


O  O 

8<  I  or  S^     ; 

0         o 


that  la,  wbetber  ths  aulpbar  Id  aulphoDlc  acidi  is 


totrnvnlont.orlicK.^vitloRt.    Thoidlcyl-siiilpltonioflcldit  >ro  Btrosglf  aeld, 
Tory  lijgrowiipic,  erystalllno  sub»(Rii'Cea,  and  rery  soluble  in  water, 

la  the  ttbovo-ineritioiied  couipounds  C„ll,„.,-S<.>tCl,  caIImI  ntl- 
ptionic  chlortdta,  chtoriiiu  ohii  be  rrplacwd  by  hydrogen  when  it  acta 
on   thecn  in  the  oascent  ctato  ;  tlio  bodies  tbus  ob<aiii«d  have  iha 

formulH  CnTI,n-.-S,j',   and   are  ciillod  ntlphinh  acuta.      Wlieii  an 

allEyl  halido  roiicU  with  tku  iwlium  sail  of  a  auiptiioio  acid,  a  aal- 
pbooe  is  formed  (67): 

CH..S*J.^ j-CH,  =  J^*J[>SO,  +  SaBr. 

This  modo  of  ptwparntion  Is  a  proof  of  Hid  cotiEttilution  of  tbo  snt* 
pboiics. 

Atinlogoua  aileniuin  and  tellurium  compounds  aro  known,  cor- 
respoiidiog  lo  tbe  majority  of  the  Aulpliiir  compounds  jual  described. 
Theae  also  liaTit  a  most  oflTeusiTe  BmsU, 


ALEYL-RASICLES   LINKED   TO   NITROGEN. 

I.    &MIKBB. 

69.  At  the  beginaiQg  of  tho  prcrioua  section  (66)  it  is  stated 
tbat  the  propcrtiwt  poeaciasL-J  hy  iaorganic  cumpouails  are  even 
mom  marked  in  their  urgonic  derivatircs.  I'hu  uompounde  tu  he 
described  in  this  acction  afford  another  striking  cxamplo  of  this 
phenomenon. 

The  tfrm  amines  is  upplietl  gencmlly  to  siibstfliicoe  which  majr 
be  regarded  ai  derived  from  ammonia  bv  exchange  of  hydrogen  for 
aUcyl-rwltclee.  The  most  chnrarterislio  prnpert-y  of  ammonia  t8 
its  power  of  combining  with  acids  1o  form  salts  by  direct  addition: 

Trivalcnt  nitrogen  iti  thereby  made  pentaralent,  a  chango  ap- 
parently intimately  connected  with  its  liasifl  rhnracter.  TbU 
property  ia  ulsu  found  among  tliu  nlkylamines.  They  arc,  at  leu«t 
those  low  in  the  ocrivs,  bctt«r  conductors  of  electricity,  for  the 
same  niulecular  Louccnt ration  of  their  aqueous  soliitiono,  and  are 
therefore  more  Btrongly  basic  than  nmmonia  {"  Inorganic  Chem- 
istry," 66  and  236).  This  applioH  aliM)  to  the  organic  compouuds 
corresponding  to  NII.OM,  ammoniwm  hydroxido.  The  laet- 
nnmed  uibetance  is  not  knovn  in  the  free  etate.  but  it  exists  io 
tJio  nqneoos  aoliition  of  ammonia.  It  is  very  unstable,  being  eom- 
pictely  decompOEied  into  vrator  and  ammonia  when  its  (tolution  ia 
boiled,  it  has  only  veakly  basic  properties,  because  there  are 
bat  few  Nll^-ioua  and  OH-ioua  in  its  aqueous  solntion,  apparently 
beoause  the  compound  NU,011  has  a  Tory  strong  tendency  to 
bnwk  up  Into  NH,  and  H,0.  Siich  a  dccoDiiK)«ition  is.  however, 
no  longer  possible  for  compounds  containing  four  alkyl-groups  in 
the  place  of  the  four  hydrogen  atomt)  of  the  NIT, -group;  esperi- 
cDce  haa  shown  that  these  compounds  possess  great  stability. 
Since  Ihe  nitrogen  cannot  revert  to  the  triralent  condition, 
their  basic  character,  in  comparJBon  with  tliat  of  NH,OH,  is  so 
strengthened  that  they  are  ionixed  to  the  same  degree  as  the 
alkalis;  they  are  almost  completely  split  up  in  Dolutlona  whose 
dilutiou  u  tJ-b  of  the  normal. 

The  amines  yield  complex  salte  fully  analogous  to  the  ]>latinum 
Mlt.  (NHJ.PlCl,,  and  the  gold  salt,  NH.AuCI.,  of  ammonia. 


AMINES. 


H 


f^wlth  tho  alkyl  lutido,  Yielding  the  halogen  salt  of  a  quator- 
nar;  ammonium  bsisu: 

It  is  oBsumod  in  the  foregoing  that  excess  of  ammonia  is 
employed;  but  oron  vhen  this  is  not  the  oa«e,  and  in  general  Cor 
every  proportion  of  nlkyl  hnlido  and  ammonia,  tho  r«action  tnk«g 
place  in  theae  four  phases.  The  final  result  is,  tlierefore,  tJiat  the 
primarr,  wcondary,  and  tertiary  amines,  and  the  ammonium  base, 
are  formed  together.  It  is  often  possible,  however,  bo  to  adjust 
the  pro{>ortioQ  of  ammonia  and  alkyl  halide,  together  with  the 
dnration  of  the  reaction,  etc.,  that  a  giren  amine  is  the  main 
product,  and  the  qiiantilies  of  the  other  amines  are  small.  The 
nature  of  the  alkyl-gruup  also  exercifiBS  a  great  influence  upon  the 
character  of  the  rwicl  ion-product. 

Tilt!  separatioji  of  the  mizfurf  o/ tJ mines  fo  ohtuincd  Ik  often 
difficult,  there  being  no  method  getioraily  a)>i)licable.  The  i>cpara- 
tion  of  the  ammonium  bases  from  the  ammonia  and  amines  is 
cimpte,  because  while  thfc  aminos  are  1i(iiiid»  rnlfllilizing  without 
decomposition,  the  lower  nienibers  being  eren  gnses  tiie  am- 
monium bafiCB  ant  not  volatile.  When,  therefore,  the  mixture  of 
thr  amine  hydrohalides  and  the  ammonium  ba.<ieR  is  distilled  after 
»dditioii  of  caustic  potneh,  thn  frre  aminefi  only  pUBS  over. 

In  order  to  Boparate  tho  primary  from  tho  mixture  of  the 
hydrohalidet?  of  the  tliree  aminos,  fractional  cryntallixatioD  is 
hirgely  made  use  of  in  tlieir  preparation,  at  le««t  in  the  caeo  of  the 
loiggft  memhera,  methylamine,  dimethylamine,  etc.  The  higher 
"''^''ceoafc  l>egimiing  with  the  propylamines,  can  be  separated  by  frac- 
tional distillation.  ' 

YatiouE  methods  of  preparing  primary  amines  unmixed  with 
aecondarr  or  tertiary  are  known  (88,  104,  244,  254,  and  388). 

The  veiiM-'ilif  of  the  forrnnliiMi   uf  letraaJi-t/hii/ttriojiititit^  iodides 
from  tTiethylamine  and  an  alkyl  iodide  or  bromide  has  been  iuvee- 
I  tigated  1>r  Menschutkin.     U  is  apparently  a  MmolectiUr  reaction 
[("luorganiv  Chemistry,"  60)i  and  therefore  taltes  plaoo  accurding 
[to  the  equation 

dx 

-wboTe  1  is  the  Teloeity,  k  the  constant  of  the  reaction,  a  and  h  the 
qDonUtiec  of  amino  and  iodide  by  unit  Tolume  expressed  in  mole- 


AMINES. 


85 


taristic  odonr,  and  are  slightly  Bolullc  ui  -water.  Tboy  ow  taxQj 
reconverted  into  B«coQdarj  iiminc«  bv  the  iiction  of  concentrated 
bjdrochloric  acid  (285):  this  u  n  prnor  of  the  tttructure  givoiL 
aboTe,  because  if  the  nitmso-groii]>  weri>  dimctly  linked  to  h  cnrbon 
atom  either  Itr  itH  oxygen  or  by  itH  nitrogen,  it  would  not  be 
poaeible  thus  to  reoonTert  it  into  u  Bm-ondarr  amino. 

Tertiary  uniinv«  are  unacted  upon  by  iiitrouis  acid. 

Their  behaviour  with  nitrouB  uxiid  i«  therefore  n  means  of  dis- 
tinguishing the  three  elassea  of  amines  from  one  another.  It  also 
serves  as  a  hasiB  for  the  eepanitioii  of  the  secondary  and  tertiary 
amines  in  the  pure  state  from  a  mixttire  of  the  two.  When  a 
concentmtcd  whition  of  aodinin  nitrite  is  added  to  a  hydrochloric 
acid  solution  of  »  mistnre  of  the  {.uo  amincR,  the  Bccondsry  amino 
is  converted  into  a  nitrosamino,  vhieh  eollocta  a«  an  oily  layer  or 
the  mrfaee  of  the  atjueoun  Kolutiou,  and  can  be  romoved  by  nionjis 
of  n  eeparoting-funnel.  'l*hti  tertiury  amine  l*  not  attaekod,  but 
remains  in  the  aquooua  solution  in  the  form  of  a  salt;  it  ean  be 
obtained  by  distilling  with  caustic  potaeh.  It  ehould  be  mentioned 
that  any  priuiary  auiiue  vhich  may  be  present  is  decomposed 
during  the  procees. 

Another  method  of  difftingniahing  between  j)riiiiary,  seeoiulary, 
and  tertiary  amines  conslstei  in  the  determination  of  the  number  of 
Alkyl-gruupg  with  which  the  amiin.'  can  eoinVmc.  For  example,  if 
a  compound  t',U,N  ii  projiyUmim*.  C,H,N  11, .  it  should  yield,  when 
heated  with  excess  of  muthyl  iodide,  a  compound 

C.H, 

Blionld     yield 


^•■''Ni  =  ('.H,.Ni; 


if     C.n,N-=<g^.>KH,     the 


8nme     treatment 


^^\  ^'I  =  C,n,.NI;  kaUy,  if  L'.ILN  =  (CH,).N,  there  would  be 

ohtainwl  (CII,),NI  =  C,n„NI.  A  titration  of  (he  iodine  ion  of 
the  quaternary  ammonium  iodide  formed  ie  KuQicicut  to  determine 
whether  C,n,X  is  primary,  secondary,  or  tertiary. 


Individual  SletiiberB. 

73.  The  lower  membere  arc  infiammablc  gases  which  are  very 
•olublo  in  water;  thne,  U50  volumes  of  methylamine  dissolve  in 
one  volume  of  water  at  IS'S".     Tlie  sucoeeding  members  bare  low 


Ifttt 


B6 


ORGANIC  CHEMISTRY. 


boiling-pinnU,  and  arc  mieoiblc  witlt  wiUvr  in  all  proportions.  Botb 
tlivv  a\A  thv  low«et  mcnilxirs  have  a  oboractehstio  ammoniacal 
ein<>ll,  like  boiled  lobstont.  The  highest  members  nrc  otlourloiw 
and  itiiiolnblo  in  water.  The  apeoiSc  gravities  of  the  amines  ere 
nppieriiiHy  less  thiin  1,  that  of  methrlaminfl  being  only  0-690 
at  —  11".  Tlifl  following  tablo  indicuics  tho  vuriationa  of  tboir 
boiling- pointB: 


Alk;l-IUdii^. 

FrtwatT- 

SnRoadj  ry. 

TBfitti-y. 

—  fi" 
18° 
«• 
76' 

180' 

r 

1«0" 
S9T 

8.r 

fiO' 
IW 
215* 

866' 

Methylamine  occurs  in  MercuriaUs  ptrenriu,  dimtthylarmne.  and 
trifaetkylatnine  in  herring-hrino. 

TelramtthylammOnuim  /ii/droxide  h  obtiuneil,  liko  ail  its  homo- 
logitee,  by  treatment  <>f  its  lialoid  acid  salt  with  moist  aiker  oxide, 
Ag-OH;  it  ia  a  whito,  L-ryntallino  mass,  sthI  U  very  liygroecopic- 
It  is  ilecomposwl  by  he«i  into  triraHtbylaminu  and  methyl  aJoohol: 

(Ciu\-on  =  (Cig.N  +  cix,on. 

The  higher  ammonium  boaee  are  converted  lij  heat  into  a  tri- 
alkyliLQiine,  water,  aud  a  hydrocarbon  C'„1I^: 

(C,uj,N.OH  =  (p.n  ).?r  +  o,rr  +  n,o. 

The  Btnicluro  of  the  ammonium  Ijasea  is  thntt  explained.  The 
nitroften  atom  is  the  only  one  in  the  moleculo  which  ia  able  to 
linlt  itself  to  the  four  monovalent  alkjl-groupa,  and  to  the  mono- 
valent bydroxyl-groiip.  It  must  bo  assumdl  to  be  peutavalent  in 
tbese  oompounda.  and  tb«  couBtitutiou  of  the  iiuunoniiuu  bases  is 
theroforo 

in  which  n,  m,  p,  and  r  nuty  be  Hko  or  nnliko. 

AIkyI-d«riTAtlre«  of  hydraritu  or  diamide,  TT,N-NH„  are  abo 
known.  Among  tlie  methods  for  their  prepamlion  may  bo  mentioned 
tlie  direct  iotroduetion  of  aa  alkyl-gronp  into  hydnutioe,  and  the  car»> 


AMINES. 


St 


fol  redaotloQ  of  nflraeftmiTiM  (73).  Tlioy  bare  Hllle  power  of  rasist- 
aceo  tonards  oxidizinK-ngents,  an  alknline  copper  Boluti»n,  for 
ezample,  tNjing  reduced  t»y  them  at  the  ordirmrj-  lemperatnrft. 

74.  Triefhytammf  u  soluble  iti  wiitor,  aUliougb  nL  about  30°  thu 
solution  Beparaira  into  two  layow.  Thw  upper  of  tbeae  voiisisU  of  n 
BolutioQ  of  valrr  in  tho  uniitii-,  nntl  the  lower  of  a  aoliitioa  of  tbe 
Amine  in  water.    Iii  tbe  neigbbourbood  of  30*  n  slight  nse  ia  temper- 


nt 


3* 


t  'ii)'w'»'il>'iDgbA>'  n'^ 

Flo.    ST.~-$OLl-])ILITT  CUMTB  r«lt  Tlt»ILTUYLA>II»tt  UID  WATn. 


«    ID    it    M   •>    Ml '  do    ^    a>   n  iM 

TtartlUTulM 

FlO.   S8. — U9DAL  FORH  Of  Bol.rBlI.ITY   CCH'»-B   VOK  TwO  LlQClOS. 

klure  id  able  to  tftvei  tliia  separation  into  tno  layen,  merely  boldioif 
tbo  Inbe  for  a  moment  in  tljit  warm  li^nd  iHiiii)^  sufl1(!l«nl. 

Why  tbia  Miper&tion  takca  plucc,  and  nl  ^'bnt  Iciupcraluro,  »  moat 
eaailf  nndemtood  by  u  cotisidpratiun  of  tlie  cttrra  of  suiubilily  of  the 
syatau  auune  +  water.  This  ammo  (Fig.  37)  is  leas  tolublo  Id  waroi 
vater  than  m  cold,  and  below  20'  is  mtncible  with  water  in  all  prapor- 
tious.  If,  for  example,  iiicreaainK  quantities  of  the  amino  be  added  to 
vater  at  30*.  it  diuolves  until  the  amount  ot  acuino  re-.icbi»  about  5f 
tCf.  rig.  S7).  Th«  solution  in  thou  siituratcd,  and  addition  of  mcr«  of 
the  amine  produces  a  second  layer  of  liquid.  On  the  otiier  hand,  kLvd 
vater  is  added  to  trImotliylaiuiDe  at  S&",  it  dtsaolves  until  the  aotoiiDt 


88 


ORGANIC  OitMISTRY. 


of  water  naclies  aboul  SS  \fif.  Fig.  37>;  twyoiid  (liU  point  ttro  layers 
nni  tonnod.  Tlio  line  DCis  I  ho  eolubility  curve  for  water  tliMolvcd  in 
trimetbylamine,  and  the  line  AB  that  for  trimelbylamiuc  in  water. 
When  tlie  [ciiiperaLune  fall^  tlie  solnbllity  of  tli«  irater  in  tbe  amine 
lacranAca  on  the  one  linnd,  and  on  tlio  oihor,  that  of  the  amine  in  tbe 
water,  so  ttiat  Ilic  eolutiilUy  lines  mcot  one  anotbor  bolwecn  B  anil  C. 
Tlie  whole  area  is  liieo  dirided  intw  (wo  parts  by  the  solubility  I'urres. 
All  the  ))olnta  within  i1  ffCZ>  carresfiond  to  two  layers  of  liquid,  and 
nil  tliD  poinis  oiitRide  it  to  a  honiog^nooux  niiilure. 

If,  fur  ciumple.  the  nbscissA  PQ  is  drawn  for  n  mixturo  of  SM  of 
amino  and  80<of  water,  lii«  tnizture  is  homogeneotis  for  all  lemiwr- 
aturos  U|i  to  tlio  paint  if,  and  Iietorogenoous  abore  that  temperature. 
Along  tlie  very  .it4>ep  portion  of  the  currc,  repre-iented  in  this  epeoinl 
COM  by  the  iiurt.  BC,  a  sliglil  rise  la  temperature  must  evidently  r<«iiH 
In  sv|inmtioii  of  IIk>  liituiil;  because  although  at  ab<^)iit  SO*  Mho  )t«>liit  K) 
two  lifjuid  layers  are  just  about  to  form,  of  wbicb  tlio  aqueous  Uycr 
would  conlaiii  2M  ot  amine,  at  R',  oorresponding  to  an  ineresse  of 
teniperntureof  IfiAs  than  I*,  the  lalttT  coiilitiiis  60^  of  amine,  when  tbo 
Ii(]ii<<l«  tnitgl  Koparalo  Into  two  layers.  It  followa  that  in  this  pari  of 
the  curru  a  einiill  rise  of  tempLTaluro  must  cauao  a  Ec|)aratiou  of  wiilcr 
Buflleieul  to  alter  Ihti  oompoBiliou  of  one  of  the  layers  from  30](  to  WK 
of  ami  I  in. 

It  liofi  biicn  already  montlonod  that  the  rolalivo  solubliiiycnrvc  for 
the  system  watt^r  -f  triolbylumiiia  has  a  B|)ucia]  p»th  in  the  iiortiou 
SC.  Tbo  wholo  ourvo  dilters,  liovovor,  from  thoso  ohtalnod  In  ordi- 
nary cases.  Tbo  Bolubiljty  of  liquids  which  nro  partially  misclblc  with 
one  another  usually  incTeases  with  tbo  temperature,  just  as  in  the  ease 
of  tiolida  and  liquids.  Thu  eurvv  ia  tborofore  exactly  rereraed)  so  tbat 
It  it  usually  as  reprMeutiKl  in  Fig.  28. 


II.  BlTBO-qpMPOOinJB. 

76.  'Wlien  ailver  mtrite  ruacW  with  au  alkyl  iodide,  two  com- 
pounds are  formed,  both  of  which  hare  the  empirical  fonnuU 
CoH,„i,NO^  They  have  diftercnt  boil iug -points,  there  being 
obtAincd  from  ethyl  iodide,  for  example,  a  substauce  C,H^NO,, 
boiliiif;  at  17^  and  another  boilinj;  at  IIS^-IU".  The  two 
iBoinent  are  thertfore  easily  SBparatt'd  hy  fratrtionatioii. 

Tho  compound  of  tower  boiling-point  ia  decomposed  ioto 
alcohol  and  nitrous  acid  by  the  action  of  cauatic  potmh;  it  must 
therefore  be  looked  upon  a»  uii  ester  of  nitrous  acid,  beitlg  formed 
vx  MOcordaDoc  with  the  following  equation: 


NITROCOMPOUNDS. 

TVTion  thcHo  cstcrt,  or  alkul  nitrites,  are  reduced,  tliey  are  con- 
Tcrtcd  into  an  Alcohol  nnd  ammouia. 

Th«  comiioninl  boiling  nt  ttic  higher  t('mp«T«liir(>>bchavee  quite 
differently.  It  in  not  convcrtert  into  »  nitriw  nnd  alcohol  by  tho 
actiou  of  alkalU,  arij  on  rerloction  itfi  two  oxyppti  atonm  aro 
replacoil  by  two  hydrogen  atonu,  with  the  fonnation  o£  a  primary 
amine: 

The  tut  reaction  sliowa  that  the  nitrogen  in  this  clasB  of  com- 
pouitilft  is  directly  liiilivil  io  caTbi>ii,  because  tliiit  ia  the  ca«e  witl 
titc  amines  Tli«  oxyg«n  atoms  cannot  bo  bnlced  othervise  thaal 
t«  tho  mtrogon,  becauac  the  reduction  to  amino  takes  place  at  tho 
onlinary  tompiTBinrH;  it  in  not  poKsIblo  iimlor  these  oimditionx  to 
replace  oxygen  whiL!li  i>!  linked  directly  to  carbon,  for  neither  from 
alcoholn  nor  from  ethers  i«  it  posaible  to  obtain,  by  reduction  at 
low  tvoipemturcs.  Bulwtaiicca  whinh  do  not.  contuiri  oxygen.  Tbiu 
le«ids  to  the  conclui<ion  tliut  tiu'sc-  xubetuuccs,  which  arc  uUlei 
nUro-etmipOHndf,  must  have  tho  conirtitiilion  C„H,„^,— NO,. 

Xitrty-eompounds  t/n>rf/ort  contain  a  group  XO^,  lht>  nilr^am 
atom  of  which  is  directly/  liiil-eil  to  carionj  the  ffrotijt — .VO,  fm 
eiiUed  the  nifro-group. 

The  namea  of  thcan  compounds  ore  formod  from  those  of  the 
iiaturalcd  hydrocarbons  by  the  Addition  of  \\\<i  prefix  mtro.  The 
compound  C'1I,N0,  is  thus  nitromethune;  C,HjNO,  is  witroethaM; 
cl4!.  yitropara^Ks  is  the  gciioml  name  of  the  members  of  this 
Itomologons  series.  They  are  cokmrtefw  li<)uidB  of  etheroal  odour, 
iho  lower  terms  being  slightly  soluble  in  water;  they  distil  with- 
oat  deconi(>o8ition. 

76.  The  nitronlerivativeB  have  a  number  of  characterifltic 
properties.  One  of  these  is  their  poEfi^Hsing  one  hydrogen  atoi 
replaoeulile  by  alkali-mc-tals,  e«|jecially  godiuin.  Thts  sodium 
compound  18  meet  eabily  obtained  by  tho  action  of  Eodium  elhytate 
or  methylntc  upon  tbu  nitro-compouud  in  alcoholic  solution.  A 
fine,  white,  crystaUino  procipitatc  is  thus  formed,  which  in  tho  case 
of  nitroethauo,  for  exaiiiplu,  Imtt  the  composition  C,H^NaNO^ 
The  intolubility  of  tlicsc  lodiiiiu  compontids  in  absolute  alcohol 
can  anmetimee  be  made  use  of  to  separate  the  nitro>paraffins  from 
other  substuices. 


90 


ORCMSiC  CHEMISTRY. 


This  pow^r  of  exciunging  hydrogen  for  eodinm  onl;  exists 
Then  there  ie at  least  one  bjrdrogea  «tODi  linked  to  th«  carbon  atom 
to  which  the  nitro-group  is  attached,  lu  the  eame  tav  as  from 
nitroethnDe,  a  metallic  compoQud  is  uldo  obluiued  from  secondary 

nitropropwio,   CH,-CH<^q«:   bat  aitrobotMi*,  OH,^C-NO,, 

does  not  ricld  any  oorrvsponding  motatlic  dorivutirp.  It  VOS 
fonnuri;  euppOMsl  that  the  malollic  atom  in  thc^e  «odium  com- 
poands  occupied  tho  position  of  a  hydrogen  atom  which  vas  linkod 
to  tho  corboQ  atom  attached  to  tho  NO,-group;  thog  C,li^NftNO, 

/NO. 
mw  BQpposed  to  baT«  the  strnctare  CU,-C-^II  It  has  booD 

^Na 
fihovD  thai  this  is  not  tho  caa«,  as  will  bo  indicated  in  tho  seotioD 
dealing  with  the  pftuil^actdi  (SSI). 

When  an  ulkaliiic  snlacion  of  a  nilro-componud  U  brought  into 
contact  with  biommc,  one  or  more 'of  its  hydrogen  atoms,  when 
linked  to  the  mme  ciirbon  atom  as  the  nitro-group,  is  leplacod  by 
lirumiiie.  This  reaction  is  analogouH  lo  the  abuie-mentioned 
siib«tttulion  by  molals,  it  being  etill  possible,  for  example,  to  iu* 
troduco  ono  bromino  atom  into  Cll,  ■  CiiBrNO, ,  but  not  into 
/Br 

cu.-ofcn.. 
Nno, 

77.  Th«  behaviour  of  nitro-flompouods  with  nltroaj  acid  Is  very 
obarnct eristic,  and  allordfi  a  motliod  of  disliDguishinj;  pniuAryi  wc- 
ondary,  aud  lerliarjr  tiitro-ttenvstives  from  oiiu  noothor.  Tli«  reac- 
tion is  carried  cut  by  adding  sodium  iiitrile  lo  aii  alkaline  solution  of 
the  iiitro-eompoiiiid,  niid  (icidifyitig  witVi  dilute  siiliiliuric  acid.  lathe 
CSM  vt »  piimarj  nitro-camponnd,  an  alk^Unitrolic  acid  is  formed  : 

cir,.c|H7To|NOH  =  ch.  c^j[^**^  +  h.o. 

\N0.  BUkrlbtirolle  neiil 

The  conslitotiou  of  these  ocmpoimdA  is  indicated  by  their  prodoo- 
tloo  from  a  dibromonitro-eomponnd  by  llie  action  of  bydroiylamine, 
H,NOU ; 


NOH 


OH,.C|Br,  +  H.lNOH  =  CH,  C^JJq" 

\xo, 


eHBr. 


The  alkylnilrollc  ncid»  dissolre  in  alkalis,  yielding  melallic  com- 


NITROCOMPOUNDS,  9> 

ponnds  with  a  blood- red  colour,  tbls  reaction  affording  a  cbaracleristic 
test  for  them.     They  crystallize  well,  but  are  by  no  means  stable. 
The  secondary  nitro-compoands  yield  pseudonitrolt  wheo  similarly 

treated.    They  contain  tbegroup  =  C<2qQ  : 


Propyl  pseudomtrol 

The  pseadonitrols  are  colourless,  cryBtatline  substances,  which 
hare  an  intense  blue  colour  in  the  fased  state  or  in  solution;  this 
characteristic  serves  as  a  test  for  them. 

Lastly,  the  tertiary  nitro-compounds  are  not  acted  upon  by  nitrous 
acid. 

Among  the  other  properties  of  nitro-compounds  may  be  mentioned 
their  decomposition  into  the  acid  containing  the  same  namber  of 
carbon  atoms,  and  hydrozylamine,  when  heated  with  hydrochloric 
acid: 

CH.CH.-NO.  +  H,0  =  CH.-COOH  +  H.NOH. 
Nltroethuio  Aceiic  acid      H^drozjlamlM 


ALKYL-EADICLES    LIHKZD    TO   OTHER  SLEKENTS. 

I.   AUCn-BADIOLEfl  LUTXED  TO  ElZmim  OP  THE  HITftOOEK  QBOITP. 

78.  Ammania  unites  rvudily  with  uciilH,  with  rormnlionof  suits. 
PboHphoroMcJ  livdrogen  a];^  jioscMnucii  thin  properly,  Kllliough 
tho  plioftphoQhim  saXti.  Fll^X.  &ro  deoomposcd  oren  by  water  into 
AD  ftcjd  and  phojiptiorptli^d  hydr(iR«'n. 

Th«  basic  charaott-r  has  whnlly  ilimpponri'd  iu  tho  ciwc  of 
arwiiiuretted  hydrogt'n  aud  HJitimoniurelted  liydrogpu:  bi-iniiitb 
does  not  yield  a  lirdridr,  mid  p(iiue«R««,  in  f&cC,  onlj  very  iilight 
traces  of  the  chttrndteriHtins  of  inetiil1oid.<). 

Amniouia  cannot  bo  cosily  oxidized,  «nd  is  unacted  iijion  by 
tbe  oxyjrou  of  the  atmonphcro  at  onihian-  tempcrftturos,     Ou  tho 
other  liaiid,  tbe  hydrideg  of  phoepIionjB,  arsemc,  and  antimonyi 
are  eiuiily  uxidi;)iMl. 

All  Ihtt  ahovL'-iiicntioned  properties  are  dUplayed  by  tbo  com- 
pounds wliich  these  olonienta  form  vrith  alkyl-iadiclctt. 


FhMpblnes. 

79.  Thfi  KtninM  jieM  stronger  basM  than  (immouiA;  in  th« 
way  :ti«  phwpltiiirt  viclil  ftlrorjcer  Imsoa  than  rili,  this  becoming'' 
mor«  mnrkM  vliti  incrcasa  In  the  DumtMr  of  alkyl  groiifw  v\\k\i  biire 
re|tlnct>d  hydrogrn  atoms.  Tho  Htlta  of  tho  inonoalkyl-plii>«tiliiim,  fur 
i>*Ani|>le,  nre  dt>«>mpogetl  by  water,  wh«reas  lho»e  of  tbe  tiialkyl-pIioA- 
pliincs  iiiirl  irialltjl-ithospliiiicsHre  not.  "iiwqituUrnnryjifioiiphoHiHm 
bastx,  I'R.OII,  are  as  stnHigly  ba.^io  na  the  nmnicitiiimi  Im^t^s.  Wli«n  a 
pho^)boiiiuui  biisc  is  beali^d,  it  dors  not,  like  an  Hiiimoiiium  Ikini',  Hplit 
Dp  into  an  alwlnil  (or  Callm  +  ll,0)  nnil  a  Iniilkyi  bas^,  bnt  iuio  a 
hydrocarbon  C^IItn  i  ■  ni'd  an  oxygen  compound : 

(CE.).POII  =cn.  +  (C,I!,>,.ro. 

Thb  subatanw  Is  callwl  tritthyiphosfihine  oxide.  In  tbfs  reu>tian, 
tho  great  affinity  betwrcn  pho&phorus  and  oxygen  jilayH  an  iiiiportnnt 
part,  ttiia  afflnily  boing  ako  indicated  by  the  eau  with  wbleh  the 
phoAphiuei)  undergo  oiidation,  a  chnnge  ofr«ct«d  cvon  by  tbo  actlnti 
of  lh«  air.  Nitric  acid  oiidiww  PH,  tn  phoBphoHo  aoid,  OPcOH).;  ia 
ananalogous  manner  the  pboe|)tiinQs  take  up  one  oiyg«o  atom,  and  ia 


PHOSPHINES  AND  ARSINES, 


93 


addtlHin  M  iDAoy  oifgen  atoms  u  then  are  bydrof^en  atonw  directly 
linked  to  pliosphonis : 


'^H:P*rtre.^gH;,P:0; 


H  ^  '^"*"     HO  *^  ■  " 


UanomMhit  I  p  bocphl  d  Ic 
•(.till 

noil  (CllOi  =  r  gives  iClI.).  ~V:ii. 


Dl  met  Ii  y  Ipli  iM  pbtalto 


TiimvUiyJplKMplilni)  oilda 

The  voDstilution  of  these  compouQds  is  proved  in  various  nays : 
torioM&oce,  by  lite  fiwt  that  ttie  monoaifiyl-plto^iiMie  acida  are  di- 
baaic,  tbat  the  diaikyl-jJmspltinie  acidt  arc  inonobutc,  and  ilint  the 
trMikfit-piwtpkifte  oxidts  hftve  »o  atid  t>rupcrli(». 

T)i«  [ilicsphinee  are  colourless  1i<|UKlE  witb  h  penctraiing,  stupefy- 
big  odonr.  Uelbylpliosphinc,  CHiPH,,  is  a  gaa;  tnothylpho«phiD« 
hi  Tery  small  (iiixntinns  has  an  odour  of  bynoinilis. 

Itvtbedi  of  FomatinD.— Only  tirliury  [iliuspbiiies  and  pbospUoaium 
compoutids  an;  (ormiid  by  (li«  itction  of  alkyl  halldea  ii|ion  PHt. 
Primary  and  bOOundnry  pbosphinci  arc  oblaiuod  by  hcatiog  i>hospli>- 
Bium  iodide,  PHiI,  with  au  alkyl  iodide  uud  zioc  ozid«. 


Axtinea. 

•0.  Tbc  primary  aad  Bcooadary  arsince,  UiAsCDi  and  nA»(CB«>i , 
aiv  ubuiuvd  by  rt^luutJoa  of  mouoiuetbyianteiiic  and  dtiii«tbyUr«eiiio 
*eid,  (CUiillAsO-0}[  aad  (CilOiAsO-OU,  by  aDialg«m«t«d  ttno-dust 
and  hydrochloTic  iiciil.  Both  atv  iinmiMlialely  ozidiwd  by  ilie  air. 
T«itiary  aiwnes  do  n<rt  yield  b»«ee  with  water.  Tboy  are  (ormcd  by 
tbe  action  of  a  zinc-atkyl  on  A&Oli,  and  from  aodium  antenidu  and 
U  allcyl  iodide. 

AaNa,  +  8C.IM  -  A»(C,H,1,  +  8NaI. 

ttuatentary  artonUun  basts,  however,  have  stroogly  marlcod  bask 
liropertios.  Tb«y  are  fortaod  by  the  addition  of  alkyl  hftlidM  to 
tntlary  anines,  and  trealmoiit  of  th«  resulting  halido  with  ailrer 
liydroild*, 

Tbe  nuMt  atudied  ataenio  derirativoa  cunUiiiiug  alkyl-nidicleaaic 
Ibe  dicodyl  comjjoimth.  Tli«y  were  ioveetigated  by  Bunsrs,  who 
gave  tbrni  ibis  tiatne  in  cousequonc^!  of  their  oSensivc  uacH.  Tboy 
Arc  TAry  poitoBovs.    Tb«  Damo  eaoodyi  la  Applied  to  tlio  monovaleol 

gioup^jj'>Aa— .     Cacottgl  oxidt,  I(CHi)*Ab).0,  ia  fomtvd  by  dis- 

tUUcg  arsenic  irioiidf!  Willi  the  aoelate  of  an  aLkaii-iuetal.  All  the 
oUier  ncodjl  cuiniHjti ndn  are  obtained  from  cacodyl  ottdc;  thus 
auadift  Moridr,  (CH.i.AiiO!,  in  prepared  by  boating  Ibe  oxide  with 
hydrochloric  acid.  This  chloride,  auJ  avxnitti,  CCni)iA»-A9{CB))it  ar« 
both  ipontaDeouBly  ioflauimabla  when  brought  Into  contaot  vlUi  Blr. 


94 


ORCANIC  CHEMISTRY. 


StibinM. 

T\\a  lertiury  xtihinen  nnd  ibe  guaitmery  M^onUim  Ixjses  hnve  been 
obtained  Troin  Anuniony.  Thn  tint  nnrnod  Are  very  roxdilv  oxidizAtl, 
taking  flro  HpaiiiHiiuoualy  iti  tbc  air.  Tha  stibouiiiic  bn»>s  are  quite 
as  buic  in  th«ir  ehimotor  as  lli«  corrosp'tnding  N,  P,  mtd  Ax  dorifa- 
tlTea.    The  penumietb^l-dorivatiTc  Sb(OH>}i  is  also  knovca. 

BiHUTithlnet. 

Bismtitli  does  not  yield  a  byilridc,  but  tertiary  bismulfiinea,  such 
U  (CiHt)iBI,  HH)  kiiown,  Thej'  ni-e  verv  uiisiatile,  and  explode  wben 
bented.  They  do  nut  form  uddition-produvU  nith  alkyl  halidtB,  to 
that  tb»  "  liisiiiiilbuniitru  baxes  "  are  not  known. 


n.    AIIYI-XADICLES    LIKXED  TO    THS  XLEMBITTft  Ot  THE    CAXBOR 

QBOVP. . 

81.  Tho  HomRnlB  In  encli  ^roiip  or  colniDn  of  (h(>  periodlnnyitcm 
are  diridcd  iulu  tvu  Riib>ii:ri>up».  in  otin  of  wliicli  tbv  elcnicnta  nrc  of 
an  eleci ro-|>OBit ivv,  baMO-foriiiiii);  cliarncicr.  mid  in  Ibe  other  ol  an 
elei^tio-iifgaLivc,  ncid -forming  cboiaclor  (''  laorganic  Cbemialry," 
213(  Tbo  first  diviaion  of  ihe  carbon  graiip  coiitnins  Litantum.  lir- 
coiiiuni,  and  iburiuiu,  and  lb«  avooud,  varbop,  silioon,  gbriiiauiim), 
tin.  and  U-mI.  Ic  Iiiu  ^norally  htsm  ot>&(trved,  not  men^ly  of  ttie 
carbon  group,  but  also  of  the  otbor  groupa,  tbat  vnl]/  elemeitl*  6«/m<v- 
tng  fo  fitviro-fwyafivt  xub-yrottpx  are  capable  of  yitldimj  atkfft-tvni' 
pvutuiv.  FitrltitB  roaauti,  MknmXEJEFT  predicled  in  H^TOlbal  tbe  ibcn 
uiiktiowii  I'lffiiieiit  gprfiiamuRi  vould,  in  accordance  with  its  [HKitiuii 
in  tbo  periodic  Byitcm,  yivid  alkyl-JcrivativcK;  tbia  prtidicltoii  woa 
oonfinoed  by  the  rrsuarohes  uf  Winkler,  to  wbom  wc  aru  iodubted  for 
tbe  diacovery  of  this  eleineot.  Titanium  being  ati  element  belon|iD£ 
to  the  electrn- positive  ftub-group.  and  in  many  reipecta  resembling 
tilieoii,  it  bna  not  l>ven  found  possible  to  prepare  its  ulkyl-dcriratlreit. 

The  alenienUt  xillcnn,  iierniaiiiiim,  tin,  and  lead,  like  cwrbou.  tini 
tetrftTnleut.  Ntimoroos  Att«iiipti  havo  been  mad«  to  praparo  oom- 
ponnds  containing  cbuns  of  siliouii  atoms  roaembliug  the  carbon 
ohaitiB,  Dicy  have  not  boen  successful,  iio  compounds  coutatuiuK  a 
chain  of  morn  titan  three  silicon  atoms  having;  lieerj  jirepaTnl.  As  far, 
tbervforc,  as  is  at  proueuL  koovn,  silicon  lacks  lh«  power  of  liuking 
itaeU  logrthcr  in  chains  to  Ihe  same  extent  as  carbon.  On  account  of 
Ibis  defect,  a  "  Cliemistry  of  Silicon  ",  analogous  to  tbe  "  Chemistry 
of  Carbon  ",  U  not  possible. 

Tbeetlico-alkyls  hare  acharacler  analogous  to  that  of  tbc  timilarly 
cvDBtllntvd  cnrbon-alkyl  cum |ioii rids.  For  uxuniple.  njiooti  tHraethjfi, 
Bi(CiII,)i.  and  eari»a  tetratOtj/l.  CtdU*).,  nre  Itnown;  both  u«  Ilqaids, 


LJWWCLCi   Ul>iK£0  TO  METALS. 

iLiV  BOt  Staled  upon  by  oiiiutr  fumitig  ailrte  or  fuming  &ul|)hurie 
"nn'A  the  ordinarj'  tcniper&ljrc,  bnc  ibay  botli  yiftid  sulialiiuliDti- 
prodacls  widi  chlorine.     SGieoheptant,  (C,n»),SiH,  hiia  a  petroleum- 
like  odour,  in  vrbtch  It  irMiubli-s  IriMj/lmeUiaitr,  {CiUiktCFI. 

Ori^niir  compoiinils  nf  liii  tiKvs  beon  pn|>Arud  by  Popb,  wbJeli  coti- 
rxiDilie  Sn-Mlnot  liuked  to  fourdjuimilargroupn  and  ihercfort.-  posscas 
ao  atifmm^rk  Sn-atom.  He  hae  nitio  suoueeded  lu  spUtllug  ibese  up 
loto  llieir  0[)Uc»ll]r-4ictlrQ  i»)in|iun«iitA. 


lU.    AIXTL-SADICLES  UHKED  TO  KZTAXt. 

82.  When  *thyl  iudkK-  h  warnifd  wiih  zine,  a  whito  cnratalline 
compmiiid,  (-',H,i!iii,  in  funiieil,  luid  wJiuu  this  is  muio  litrongly 
heotwl.  Znl,  unii  ZnfC.H^),  n»ult: 

SC,H,Znl  =  ZntC.H,),  +  Znl,. 

Zinc-«tliyl  can  be  aeparetDd  "by  dietlllatioii,  which  must  be  per- 
forriic^l  ill  an  tpparatiis  rr«o  from  air,  bvoaiiso  it  barns  spou- 
taneoiiely  when  exjweed  in  it,  as  do  also  iho  olhvr  ziar-alkyls. 

The  ]iietHllo*alkyU  are  (.-otourle^  lifjuids.  henvjor  tbitn  water. 
Ziiic-meUiyl  boils  at  4<i°,  zinc-etliy]  at  II8~.  mid  xiiic-propyl  st 
146". 

When  ftlkyi  iodidt-a  react  witli  sinc-alkyle,  mtitratfd  hifdro' 
carbonn  are  formed  (29): 


cS;>^^ 


■  CH 


•  CH*  -  ^"'«  "*"  2<^H.-<^H»- 


The  lialogens  react  T«rjr  «norgetically  with  ziiic-»]kybi,  yielding 
alkyt  bHiides. 

Sodittin-ailyl  aiul  poti\isivm-<iR-yl  are  formed  by  tho  aetiuQ  of 
sudium  and  potassium  rea|>r(;tiTely  upon  zinc-alkyU  These  iiii-tuU 
(Ib»ulvo  in  thu  stnc-alkyl,  au  equivalent  quantity  of  zinc  scpanit- 
inj;out.  Sodium-alky]  and  poiiuwittm-alkyl  have  not  been  obtained 
in  Iho  pure  6laU%  but  only  in  sohnioii  in  Jiiiie-alkyl. 

Very  remarkable  coinpouud»t  of  magnesium  hnvo  recently  heea 
obtaiaed  by  Obuisard.  When  mngne^inni^turnin^s  arn  Iroiight 
into  ctmlact  with  au  ethoreul  itolutiou  of  un  nlkyl  iodide,  one 
molecule  of  the  latter  being  employed  for  each  atom  of  metal,  a 


96 


ORCANtQ  CHEMISTRY. 


ruHCtion  occurs,  the  heat  (tvolTod  thornby  raising  (he  ether  'ta 
tho  boiling- point.  When  a  Hiifliciont  quimtity  of  ether  is  uwd, 
nil  the  luugnnKitiin  ent«rii  into  solution,  forming  »  compound 
C,lI^,,'Mg-I.  This  is  combin«<I  with  one  molwiile  of  ether, 
bccnUM*  on  disiilliiig  off  the  eclier  the  reAJiIiie  still  contains  one 
mole^'uto  of  that  eub«tADCO  for  every  molecule  of  the  mctAllic 
compound,  Further,  in  a  solrcnt  other  time  other,  magtiesium 
alkjl  lialide  is  not  (ormod.  The  ethoreul  solotion  to  obtained  ean 
be  nwd  with  great  adrantage  for  the  epitheais  of  s^coudarr  and 
lertiar;  alcohols,  wd  for  other  purposes  (97  and  111). 

Mervttrtf-olkyi*  aie  prapared  similarlj  m  the  sitMS  Mupounds. 
Tbajr  do  Dot  take  fire  in  the  air.  and  ara  dangerously  potMiioiia.  Sucli 
euapootida  as  Cin.-Ilg-OHar«Btroug  bases. 

Id  addiiioB  to  the  componuds  loeutioned  abort,  alkjrl-dcriTaiiTca 
of  berj-llium.  magneaium,  eadmiiiiD,  alomiAiiUD,  thaUiam,  and  lead 
bare  b*en  obtained. 


HITKILES  AMD  ISOFITBILES. 

83.  When  pfitAeaiiim  etliyl  aiilphate  is  diiitille^]  witli  (lotassium 
cyauide  or  anhydroua  potasaitim  /errocyanide.  "  yellow  prussUte  of 
potash,'' K,Fe(('N(j,  « liquid  ut  exwediiigiy  implesHUit  odour  is 
oblnined.  By  meauii  of  fmctiotia]  dUtillaltoit  it  ciui  he  xeparater] 
into  two  portions,  both  of  wliiuli  liave  thu  (ornmla  C^U^N.  One 
of  lliesR,  which  ix  L-iilW  fifti/(mrh^i/!aiiiine.  Is  only  prt-aetit  lu  Hntal] 
^iianlitiL-.i(;  it  huUii  ul  Si'-,  utiiI  has  tlit-  eumc  diMifrrt-eublB  email 
u  the  ori;{Jnul  mixture.  Th*  olliei*,  wLJch  constitutes  the  maiix 
portion,  h  culled  efhi/l  ci/anitif  ;  it  hoila  at  !)7^,  and  after  purifini- 
tinii.  hai!  nii  odour  by  no  mentia  disajirpeabln,  and  muuh  lofls, 
]>eai-lnttiii^  than  that  of  the  other  c-ompuund. 

Thpxe  iiininert:  b(<huve  quito  differtnitly  when  acted  upon  by 
inorganic  acida  Kthrli-urliylaniini-  ie  utliu-kc^d  by  thom  at  ordinary 
t«inpenitareB;  iti;  dittagrucublu  odour  diftappeun,  and  thv  isubstsnce 
itself,  rliich  at  firrt  floated  npon  t,h*  acid  in  the  form  of  an  oily 
layer,  goea  wholly  into  itolittion.  For>/nc  acui,  C'M,(>,.  can  bo 
obtained  from  thi«  solution  by  distillation;  and  nn  wldition  of 
oausiiv  pota«h  to  the  reiudue  in  the  distilling- flask  and  subseqaent 
dirtilhitioii,  ftliylaininc,  {',lIjNIl,,  paHses  ovt^r,  showing  that  tho 
nitrogen  iu  ethylcttrbyluniiiio,  UjlIsN,  u,  directly  linked  to  the 
etliyl-group: 

C,H,N  +  211.0  =  t'H,0  +  C,H  NH^ 
BthrtoArbjIaaiin^  Formic' aod       Eihyluuliia 


Ethyl  c}'anide  is  only  slowly  attaclLed  by  inorganic  ooids  at 
ordinary  temperaturcB.  bui  more  qiiiekly  on  heating.  The  reaction 
ii  carried  unt  in  a  flaek  wiih  n  rotlux-condoDBer.  tuid  if  after  its 
compk'tiou  the  litjiiid  is  distilled,  ^^roptortic  acid.  C^H^O,,  psRsen 
Dvor.  This  acid  contains  the  same  niuiiher  of  carbon  atomei  hm  the 
original  fompound  CJI^X.  On  making  the  reaidno  in  the  flask 
a)kalin<'.  and  dietilliug  again,  a  volatile  btwe,  aritTiujnia,  ie  found  in 
the  diitillftic.  The  nitrogen  in  ethyl  t-yanide  cannot  therefore,  ho 
direetly  linked  to  the  ethyl-radicle: 

O.H.N  -f  aU.O  =  C.H.O,  -f-  NHr 


,8 


ORCAfilC  CHEMISTRY. 


I 


It  inu^t  be  coucladed  from  tbee?  fucte  that  the  uitrogeD  of  tb« 
oompoiiiid  with  the  lower  boiling-point  is  directly  liukeJ  to  the 
olhyl-groui»t,  autl  the  three  carbou  atom^  itru  uot  directiv  liuked 
to  each  other,  in  \now  of  the  e»ae  with  wliich  one  of  the  carbon 
atoms  cnn  be  split  off  as  formic  acid;  on  the  other  hand,  there 
tniiRt  bo  a  chain  of  three  carbon  iitom»  prejient  in  the  cnmpoiind 
of  the  higher  boiling-jioint,  sinre  siich  ii  chiiin  is  founil  in  i)r5- 
pioiiic  acid  (87).  and  the  nitrogen  ut  not  directly  linked  to  the 
ethyl-group.  Tiieac  propertioa  are  expretwed  by  the  following  coii- 
stitutionid  fontmln;: 


I.  0^,— NC. 

Oarb/l&iRiDa 


n.  C.H.— ON. 


On  luM^niint  of  their  method  of  formation,  each  must  contain  the 

group  CN. 

Compounds  having  a  etniotural  formula  like  I  are  called  carbijl- 

amines  or  iaciiitTiicit;  thoec  having  a  titnictumi  formula  like  II  are 

called  r_Vrt"i'dw  or  mfrtlte.     The  former  are  called  after  the  alkvl- 

nidiclo    whic-h    they  contain,   thus:    mfth>flrtifhy}am\nt,  efJitflear- 

btflannue,  ©tc.     The   latter  are   called  in   »u  sualogoim  nmoneT 

methffi  cyniiidF,  etfij/l  lyttNt'de,  etc.   although  the  word   uitrile  is 

more  fri'tjimutly  used,  wliuu  tht-y  an-  nunicd  after  the  acid  from 

whifli  tht-y  may  be  rcgurdwl  lui  dcriv*J.     Thus,  CH,-OX  ieacefth 

Hitritt,  and  V,H^-ilii  prQ/noHiirile,  etc. 

The  conatitiitlon  of  the  groups  — CX  and  —  N*C  requires  further 

111  *■ 

consideration.     They  are  represented  ah  — C  z  N    and  — N  =C,' 

there  bfing  in  one  case  a  trijdo  bond,  and  in  the  other  a  quadruple 
bond,  between  C  and  N.  The  reason  fur  adopting  these  fonnulw 
in  preforonee  to  »uch  a  one,  for  example,  aa  — C^N=,  in  which 

II 
free  linkings  are  present,  will  appear  later  (128). 

Tli«  exisleiiM  of  n  dlvalvni  carbon  atom  in  Iho  c;irbylamln«s.  thai 
m      n 
b  to  uy,  a  group  — N  =  C,  ij  assumed  by  Nrp  aud  some  othtr 

cheinUts. 


Carbylamines. 

84.  These  eompoiuidn  are  the  printnpal  product  of  the  reaction 
of  alkvl  iodides  with  silver  cyanide.    They  can  also  bo  formed  by 


CARBYL^MWES  JND  MTKILES. 

of  caustic  potash  »nd  chloroform,  CllCl,,  upon  primory 
aminae^  whea  they  are  obtained  free  from  aitrilc-e: 


NC. 


C^Njnj  +  ClHCl,!  +  3K0H  =  3KC]  -f  3R,0  +  C.H,  - 

On  am>[iiit  of  thu  extraordinary  Hiid  chAracteristic  odonr  of 
the  carbylnmitKis,  this  reaction  affnnls  an  exeMtlinfflif  deluaie  test 
/or  primary  miiineg,  eJnce  aecoiHlary  ami  tertiary  amiuue  vouM  uot 
yidd  carbvl amines  hy  the  reartion  reprosentcd  in  the  above  equa- 
tion, for  this  reqiiiree  two  hydrogen  atoms  to  b*"  diroctly  linked  to 
tbo  nitrogen  of  thu  amine. 

The  cjirbvlamines  are  colourless  liquids,  very  stable  towards 
alkalis,  but  readily  coiiverlwd  by  acids  into  &  primary  amine 
aitd  formic  acid.  They  yield  unstable  addition-prod ii eta,  such  as 
SCJ3,NC-:)HC1.  by  the  action  of  dry  HCl  in  ether«4il  solution,  and 
may  therefore  be  looked  upon  as  posseaaia^  veak  baaic  properties. 


NitrilM. 

8A.  Tbeee  constitnte  the  chief  prt^duct  obtained  vrh^n  potasBinm 
cyanide  reacts  with  alkyl  iodides,  or  when  it  i^  submitted  to  dry 
distil1ati<m  along  vilh  an  allcyl  poLattsium  sulphate.  It  in  »uuietjmes 
an  advantage  to  nte  auliydrous  potassium  ferrocyanide,  K,F©(CN),, 
in8t«ad  of  poUsAitim  cyanide. 

la  addllloii  tu  hcing  obtainable  by  metliods  to  be  dc-^cTihtid  in  110.  3. 
DJtrilM  may  be  prepared  by  tbe  action  of  an  alkaline  bromine  solution 
(German,  Bromlaugf)  on  primary  amities,  in  accordauce  with  the 
[«1l4wioK  eqoAtiona: 

O.H,.CU,.NH,  +  2Br,  +  SNaOH=C,HuCH,-NBr.  +  SNaBr  +  au,0. 
Cin»C{H,{NiB^i  -+■  SNaOH  =  CH^CN  +  SNuBr  +  8H,0. 

This  teactJon  In  only  spplicnble  with  advantage  to  tbo  higher  primary 
amines. 

The  Ditrilea  are  UqiiidK  of  characteristic  odour,  and  have  apecilio 
gnvitiee  about  0-8.  They  are  aoluble  in  water.  They  are  con- 
verted not  only  by  acide,  but  aleo  by  warming  with  sillcaliB.  into 
Ammonia,  and  fatly  aeids  rnntainiiij;  the  mime  number  of  earbon 
atoms.     This  proceii  is  called  saponification   of  uitrilee.     They 


100  ORGANIC  CHEMISTRY. 

have  the  power  of  fonning  addition-pruducts  with  many  sabetanoes, 
the  triple  bond  between  nitrogen  and  carbon  being  thereby  broken 
and  converted  into  a  single  bond.  An  example  of  this  class  of 
reactions  is  the  addition  of  hydrogen: 

C,H,.CN  +  4H  =  C,H,.OH,.NH^ 

T^ts  results  in  the  formation  of  a  primary  amine  vtiih  the  same 
number  of  carbon  atoms.  The  reaction  gives  a  particularly  good 
yield  for  the  higher  members,  when  sodium  is  brought  into  con- 
tact with  a  mixture  of  the  nitrile  and  absolute  alcohol  heated 
to  boiling. 

A  description  of  a  number  of  other  addition-products  of  the 
nitriles  will  be  found  in  106. 


ST.  TC.  ■WI^Tf~-S». 


ACIDS.  C,.H,,.0. 

86.  It  wfta  stated  in  82  that  n  solution  of  Bodium-alkyl  in  rine- 
allcj]  is  obtainHil  when  tUHlinni  roiictn  witli  the  lattor.  \V)ipn  a 
ttream  of  drk'  trurbon  dioxiJe  in  jiiuMied  iiitn  tliis  anliitinn,  tlmrn  is 
formed  thv  sodiura  salt  iif  uti  lu^id  wlilch  contumit  one  ctirlion  atom 
iu  tlic  nioluculc  mon!  tlmn  Ibu  iil kyl -group.  Thus,  aodium-raothyl, 
CHjNii,  yields  Bodinm  ncotnto,  C',li,0,Na.  This  roflolion  uiAV  be 
cxplftincd  by  nwmning  that  tho  sniinm  atom  is  roleiwti  from  tlin 
alkyl-gronp,  mid  reacts  with  CO,,  bflconiinR  linkort  to  ono  of  ita 
oxygen  atoms,  for  which  it  poHttBMea  grmt  jiffinity.     In  this  way 

C^..  is  ctinvertwd  into — f  <,.».       Siuc*?  thin  gmiip.  and  also  tlio 

alkj'l-radicle  from  which  tlio  sodium  atom  bus  been  Hepamted,  hare 
ono  tree  carb&u  bond  apien^e.  it  may  be  iiamimed  that  the  two 
groups  unite,  formlitg  a  roiapoitiul 


In  accordance  with  thia  peaetion  the  acids  C„Hj„0,  contain  the 
gronp — *^'<ftii  li'ikod  to  an  alkyl-radiclc.    Thia  Tiow  jg  supported 

b}*  the  lonniition  of  thece  componnda  hy  other  methodft. 

Among  HUi^h  rea^^lions  may  be  mentioned,  Gn>t.  the  Kynthf!aia 
of  the  acidH  from  the  interaction  of  an  ttlkyi  iodide  and  ]iot!ifiRium 
cyanide,  and  Hapoiiification  of  the  resulting  nitrite.  This  HHponifi- 
cation  coRsiete  in  the  adding  on  of  water,  and  fntailH  brt-'akiiij;  the 
bonds  between  atrhou  and  nitrogi'n  in  tho  group  — C  h  N.  If  tho 
bond  in  a  nitrilo  ('H,-CH,-Ct[^  .  .  -CN  were  broken  at  any 
other  point,  it  wonlH  involve  a  breaking  of  tho  carbon  rhain, 
and  prevent  the  fnrmatinn  of  an  acid  containing  the  fame  number 
of  rarbon  atomH  ait  the  nitril4>.  Tlici  saponili cation  of  the  nitrile; 
in  which  an  acid  and  imimonia  are  formed,  may  tborefori;  be  le- 
ganied  ae  taking  place  in  tlie  following  loauucr.  The  mulcctilcs 
of  water  split  up  into  U  and  OH,  the  hydroxyl  uniting  with  the 
carbon,  and  the  hydrogen  with  the  nitrogon.  If  thiK  happens 
thrw  timPB,  the  nitrogen  is  converted  into  ammonia,  the  three 

bonds  between  carbon  and  nitrogen,  in  the  nitrilc,  being  broken: 

■oi 


OKCANIC  CHFMtSTRY. 

cn.-c^on   H^N. 

The  fonnnlA  of  tbe  ncid  formed  is  not  rn,>CO,H,,  bqt 
Cn,-CO,H,  containing  mio  rngleciile  of  water  leiw.  When  one 
moleoilc  of  vHtor  is  split  oS  from  CU,-CO,n,,  there  rceulta 

oin 

Cir,-ClOlI  — *CiI,-C5<:ym  n  enbrtance  containing  tho  (orbitzyl- 

OH 
group. 

In  thin  explanation  uf  the  formation,  of  auids,  th«  oxistcnoo  of 
iin  int(*riiieiluitt>  compouud  c-uutniiilug  Uiruy  hyJroxyl-/n>ups  U 
iistnimed.  Such  Huhfttuntro^  »re  not  kiiovru,  hut  thti  HSHumpdon 
Booms  hy  no  mcaus  improbable,  becantio  componndK  oxint  con- 

taining    three     alkoxyl-groupa:     for    example,    C1I,-C.   OC  H.. 

Subetances  of  thi«  kind  iire  called  orlJio-estirrs  (159). 

The  AcidN  (?„H,aO^  can  »\so  be  formed  hj  the  action  of  carbon 
tnonoxiilo  on  mutallic  uIkoxi(le«  nndcr  thti  iiifluonoo  of  heat: 


CU,-OIfa+  CO  =  Cir^COONii. 

The  formation  of  an  ndditioiwproiluot  hetweeit  Cllj-OXa  a.ud  CO 
can  he  explained  oy  the  aH.'tnmption  thnt  the  alcoholate  first 
deoompoaeo  into  CD,  und  O'Sa. 

It  was  mentioned  in  49  and  60  that  primary  &]oohoU  arc  con- 
vertt-d  by  oxidation  into  aoids  with  tho  general  formuhi  t'„U^O,, 
coil tuin ill j{  tho  wime  number  of  ('•atoms  in  th«  molccnlo.  In 
thiii  rpnotion  tho  group  — t'll,OH  ie  oxidized  to  — COOH. 


Thv  higlivT  primnry  nleohols  can  nleo  )>□  converted  Into  the  corre. 
sponiliD)!;  iickis  by  liRHliog  Itjvni  wiib  sniU-liiu«.  fr>M  liirdrugvn  bpiug 
formed  m  *  by-product : 


CHHi.ClI.On  +  y»OH  =  C„II..  WONa  +  SI!,. 


tA  proof  of  tho  preeonce  of  hydroxyl  in  the  carhoxyl-group  is 
BfTorded  by  tho  action  of  the  ohlorideKof  phn«phoni«,  whioh  effect 
tbe  rupWemeiit  of  the  Oll-groap  by  01  in  thi>  name  vay  ns  with 
the  olcoholn. 


FATTY  ACIDS. 


'O^ 


by  metals.  Sinc«  the  lijrdrogcn  atnm  in  the  rarlwxyl-groap 
occupies  a  spocinl  pmition,  being  the  only  one  diri-t;Uy  liukcd  to 
oxygen,  it  is  nntunil  to  euppoao  tliat  it  ib  thiit  hydrogen  iitom 
which  ia  rcplnroftbln.  This  is  pa-eily  provcri  by  troniing  silver 
a<>etute,  f',H,OjAg,  with  otiirl  iodide.  Ethyl  aontat*  is  lormetl, 
Hm)  not  butyric  afid,  ax  woiih!  be  the  case  if  the  Ag-atom  were 
prf«cnt  in  the  methyl-gronji;  tlins,  CH,Ag.COOFr. 

87.  The  lower  members  of  thia  Beries  of  acida  are  liquid  at 
ordinarr  tomporaturcs.  They  can  be  distilled  without  decomposi- 
tion, and,  vhcn  piir«,  have  a  Tory  irritating  and  stT<>ngiy  noid 
odour.  They  are  misciblc  in  all  proporLioug  with  wntpr.  The 
middle  members  (C,— <.',)  liave  a  disagreeable  ninciJ  smell.  They 
are  of  an  oily  natnre,  and  do  not  niii  with  w«t«r  in  all  proportiona. 
The  higher  members,  beginning  at  0„,  are  solid  at  ordinary  tom- 


Fio.  8fl.— Mei-TiHo-roiirr  Oobtk  or  the  Pxttt  Anns 

peratiircs.  are  without  odour,  and  resemble  paraflln  in  rharacter. 
They  arc  almoet  insoluble  in  water,  and  eannot  be  distilled  hi  the 
BtmoBphcric  pressure  without  dt<i?«>iii]io8ttion.  All  the  nridii  of  this 
eerios  dissolve  roadily  in  uleoliol  and  ether.  With  the  exception  of 
the  6r«t  member,  they  are  very  stable  townnU  oxidisiug-agenlii. 

The  Hcida  of  the  aorius  0„H,„0,  are  called  the  fatty  neidtc,  on 
accoont  of  the  fact  that  the  higher  members  vtvtc  fir«t  obtained 
from  fata. 

Many  of  the  tntty  acids  oc-eur  in  nature,  either  in  the  free  Htat«f 


I04 


ORGANIC  CHEMISTRY. 


or  M  esters  Tbcy  are  of  gnwt  tbeoretical  «nd  technical  impor- 
tance. Tho  following  tublu  containe  tho  Danif>e,  foniiiilw,  anil 
certain  phf^ical  couslauta  oi  the  uonoaJ'cliaiu  acida  belonging  to 


the  Herios  GJ\^0^: 

Kudo. 

PariBula. 

HdtlnK-polat. 

BnlKBc-iMlnl. 

BpaHfleOmviV. 

r.H,«, 

<-.H,.0. 

C,H,.0. 
C.Bi.O. 
(.11,. 0, 

c,.u.,o. 

C,.H.,0, 

14-S88- 
-83* 

-  !.«• 

-  M-.V 

-  i-r 

-  10-5* 

16. a* 
n-y 

81  v 

fla-eiB* 

60* 
69 -Sa* 

101' 

lie* 

141' 

162* 

188* 

»5* 

323* 

88T.5* 

3U* 

9fl»' 

l-*81fl(10*> 

i-osuiir) 

0.W8B(I4*) 

0-9M0  0') 
0-9450  0*) 
0-818e(l7.2'> 
O-filOOfJCI'l 
(i»110(>i  P) 

Hkrgtric  Acid 

Althougli  the  Iwiling-point  riBee  regularly  for  every  innreiuie  in 
the  number  of  C-Htoraa  in  tho  molecule,  ihe  mt-Iliug-poiuta  of  th« 
acids  containing  an  eycn  number  of  C-»tomH  ara  higher  than  those 
of  tlie  acids  immediately  pruo«ding  imd  auccoeding  thcra.  with  an 
odd  number  of  C-atoms.  Thia  ia  dUtiuutly  seun  from  tho  cur^'v 
Bhowd  in  Fig.  29.  This  phenomenon  has  aUo  been  obftorvod  in 
Kumo  (jlhor  humologoua  s^riraj. 

It  is  often  necetiKtry  to  oonsidrr  tho  gronp  whifh  rcmfiimi  when 
the  hydroxj'l-group  is  Kupposod  to  he  removed  from  a  fattr  acifl. 
This  group  is  not  known  in  the  fnw  etuto.  It  in  named  aft«r  thf 
corresponding  acid  by  changing  tho  torminution  "  ic  "  into  *'yl"; 
thns, 

HCO  Fomyl, 
CH, .  CO  Acetyl, 
C.H^CO  Propionyl, 
C,lI,COButyTyl. 
C.U,-C'0  Valcryl, 
etc. 


Pormlc  Acid.  K  ■  OOOH. 

86.  Tliie  compound  derivt-s  its  name  from  the  fact  that  it 
occurs  in  the  hodieo  of  ants  {hatxa,  forimai).     It  oan  be  obtained 


FORMIC  /tao. 


105 


liy  pastting  carbou  monoxide  over  aodH-linir  at  210'^,  t1ie  vteld  being 
gDoil  (86).  IL  U,  liowefcr,  usually  prepared  by  ani>tLtcr  method 
(168).  It  lUfty  aleo  b«  obt&iiic4  by  the  oxidation  of  methyl  alcoboL 
A  pecTilinr  method  for  ita  formation  ia  to  submit  carbon  monoxide 
and  6t«am,  or  carbon  dioxidu  and  hydrogen,  to  a  silent  oU'Ctric 
discharge. 

Pnre  formic  acid  U  a  coloarlesH  HquM  with  an  imiating  orloiir. 
It$  salts  are  caiWeA  formatett  and  uru  soluLIu  in  water,  Homu  of  thum 
only  with  difficulty. 

Formic  acid  i^  dietinpuiehod  from  its  homologiieBt  first,  by 
ibe  ease  with  which  it  nndvrgooij  oxidution,  it  being  therefore  a 
good  rvducing  agent;  second,  in  being  oa«i1y  decomposed  into  CO 
and  HjO.  Wien  mercuric  oxide  is  added  to  a  Roliition  of  formic 
acid,  a  solution  of  nierctiric  formatv  in  obtained.  If  this  hf  filtered 
and  varmed.  mercurous  formate  ie  precipitated  with  0%'olution  of 
CO,)  aud  on  further  vanning,  metallic  mercury  io  obtained: 

Uwnmc  romuto  »ffrm«u 

HglOOCH  +  H|COO|Hg  =  2IIg  +  CO,  +  HCOOH. 

In  this  procem  half  tlio  formic  acid  in  the  gait  is  set  freo,  and  half 
JB  oxidized.  An  exactly  analogous  reaction  takes  place  wlien  a 
Bolntion  of  Bilrer  formate  ia  warmed ;  metallic  silver  is  precipitated, 
carbon  dioxide  evolved,  and  half  of  the  acid  set  free. 

When  formic  acid  it:  warmed  with  concentrated  sulphuric  acidi 
water  and  carbon  monoxide  are  formed : 

IMlC0jOHis=U,O  +  0O. 

The  Muno  effect  is  produced  by  the  introdtietion  of  finely  powdered 
metalliu  rhodium  into  an  atineons  Mintion  of  the  acid,  whi>ii  tlie 
rlecomiKMition  tHlcm  jilace  even  at  ordinary  t«m])aratureK.  The 
rhodium  actu  iia  an  nccolerating,  catalytic  agcTib.  Since  reactions 
whirh  of  thcmaelves  would  not  take  place  cannot  be  brought 
abont  by  catalysis  ("Inorganic  Chenustry,"  2G),  it  foUova  tjiat 
formic  acid  decomposes  of  it*olf  iu  the  above  sense,  althonpli  wi 
slowly  na  to  seem  perftn'tly  stable.  This  applies  to  a  large  number 
of  organic  compounds  (/AtV/.,  104). 


lo6 


ORGANIC  CHBMtSTRY. 


It  vill  liJive  been  noticed  thnt  the  general  properties  of  formic 
BCiii  OillcT  ill  Bomt!  ruBpefU  (rum  those  of  the  other  acidy  of  tiie 
homulo^oim  mrivi  iu  which  it  is  the  loweNt  membpr.  As  will  be 
Boun  later,  this  plienomenon  is  of  frequent  oocuirunca-^ 


Acetic  Acid.  Cn.-COOH. 

89.  This  substunci)  hiui  b«cn  kn(>wii  lonyor  than  any  other 
acid.     It  i%  outnafactiired  by  two  ditlvrvQl  nintho<i«. 

a.  By  allowing  Uilnte  aleohol,  wine,  boor,  otc,  to  bcoomo 
oxidizptl  by  <'tpoHure  to  the  air,  with  pmiln«tion  of  vinegar.  The 
oxygen  of  the  atmosphere  a<:tH  upon  the  nlrohol  with  the  aiil  of 
bacteria,  aiid  the  pn)ccjw  mnat  be  50  regulated  that  thette  bacteria 
prodncc  tli«  groatvft  possible  fffuct.  To  this  end  it  is  important 
that  tho  tompcratun-  should  be  kept  aWiit  35". 

In  the  "qiiif^k  procMs"  for  th*  preparation  of  vinegar  (Fig. 
80),  dilnto  aldohol    (il-lO*)  ia  nllow^  to  drop  on    beoch-wood 

gbaTirigs  contttiuod  in  a  vat  with  a 

perforated  false  bottom,  a.     Holes 

are  bored  in  tlie  eidea  of  the  vat  near 

the   bottom,   serving  to   admit    an 

ascending  etreain  of  air,  opposite  in 

iIire»:tion  to  that  of  the  alcohol.    The 

Bhavinga  of    buecli-wood   have    the 

effect  of  distributing  the  liquid  orer 

a  vt-nr'  Inrgtf  Biirfai:^,  iind  so  faoilitttt- 

iiig  the  oxidizing  a<;lioii  of  tbo  air, 

Mm  JRSSnHR.       <*'bil«  at  the  «ame  time  tbey  e«r>'c  M 

BI^B  '-V*jl'-  ■     ■    " — f— '        a  feeding- ground  for  the  bacteria. 

fJBWM.  . '.'"  I  .  ..  . — i::^L_^  b.   It  has  been   mentioned    (46) 

I  wKH     that  acetic  acid  ih  obtained  in  tbe 

dixtillatinn  of  wood.  Ht  treatment 
with  qiiirklimt;,  tlio  ai-id  is  converted 
into  calcium  aoetatoi  which  is  freed 
from  tarry  imporitiee  by  heating  it  to  SOti"  in  the  air.  Tho  acetic 
»ci<l  iu  then  set  free  by  distilling  with  an  cquivaloiit  quantity  of 
cont-'entrated  liydroohloric  acid.  It  can  be  puriSod  by  diBtillation 
over  potatwiuni  bioliromale,  being  very  stable  towards  oxidizing- 
agcntM. 


Fro.  30— I'llEl'ARATlOM  i>l' 
VjKSOAK  ur  TUK  "QUICK 
pKOtKHB." 


MCETIC  ACID. 


1*7 


Anhydrous ftcctiftBcid  isBolidattompemturcBlwloiTlC  -fi'fWheii 
it  haa  nnurh  llie  upiienniiico  of  io* :  Ii«ncc  tli»  namn glacial acfU^aetiL 
ll  has  a  Teiy  |wnutrtttiDg  odoar,  and  is  obtained  by  lUlowing  a  very 
cottcentmtoil  Halation  of  acetic  acid  tn  solid  ify,  poiiringolT  theliqaid 
reaidne,  melting  ttip  sniidifipd  arid,  again  allowing  it  to  crystal- 
lize, etc.,  these  operations  being  repented  until  the  meUiiig-point 
ia  constant.  A  rUe  of  tempen»t«re  and  contraction  ol  rolume  OBOur 
when  glacial  acetic  a<!id  ia  inixud  with  water,  the  maximum  rise 
aud  oontractioii  being  obtained  by  mixing  in  tbo  ppoporlion  of  ouu 
gnimme<mi>l«cul»of  acetic  acid  to  ooegramine-nioluciileof  wutur. 
This  fact  IB  I'vidt-ncL-  of  Ibo  i-xisti-iiL-o  of  n  L-onipouiid  called  oriho- 
offl/iCfifr<;(B6),withtUcrorinnIa<.'lI,C00H.U,0=CH,C(0U),. 

A  55  per  cent,  eolutiou  cf  glacial  acetic  acid  in  water  lias  the 
same  specifio  gravity  a«  tlio  pure,  anhydrous  acid.  Wlien  water 
is  added  to  glafinl  ai-etif?  iicid.  the  spwifio  gravity  of  the  mixture 
flrrt  riiiee;  further  addition  of  water  cuuHus  it  to  fall.  Thin  cir- 
cnnutanco  mnkcM  it  impuHsibk-  to  dcli-nninc  the  nnionnt  of  aeiJ 
present  in  Buch  misturea  by  tlio  diinplu  iiwj  of  tliu  hydrometer. 

The  strength  of  very  concoDlratcd  acetic  acid  ia  bc«  det'crmioed 
br  an  ot>s«rrBtt'>n  of  its  melliiig-pmut.  n  tbttrmonit'l^r  grii(lufic«l 
In  tenths  of  a  degree  being  uaod.  In  accoroaaco  with  iho  farmtila 
giT«o  in  It, 

1li«  presence  of  IS  of  w»ter  (itictl('C:iilar  weight  18)  wotild,  »Inc«  tho 
coiitlniii  for  glacifti  acetic  acid  is  39,  uauao  a  lunuriiig  of  the  frvoxing- 

UQ 

point  M)  of  T—,  or  2-16°.    Siiiuc  a  thermometer  f^raduittiMl  in  tenths 

Irs 

can  oflaily  tx-  rend  to  wttbln  ono-t  went  loth  of  a  ili;gr«e,  the  amoTint  of 

I 


water  oaii  be  determined  to  wilbiii 


or  Q.ozfa.    This  is  a 


Sid  X  20' 
dugree  of  acciirncy  tnialtainnblu  by  IkratJon. 

When  either  no  very  grout  ncciirncy  U  rcqutrod,  or  the  nretie  «cid 
is  dilute,  il  is  best  to  dctormiiie  the  strength  by  titraiiiiK  a  weighed 
(laaDtiiy  of  the  aolution  with  a  Btnndard  eoliilion  of  nlkah. 

The  rupour  density  of  acetic  acid  at  temperatures  sligblly 
above  its  hoiling-pnint  Ik  twice  ua  great  as  that  correaponding  to 
tho  formula  C,il,<),.  At  about  200",  however,  tins  vapour  denaitr 
ia  uormnl.  A  similar  phenomenon  has  been  obgen'ed  in  the  caae 
of  many  otiier  fatty  acids. 

Tbo  accialts,  or  saXis  of  acetic  acid,  are  gcncnUlj  iwlublu  tn 


io8 


ORGANIC  CHEMISTRY. 


water,  tb«  silver  salt  dissulving  with  dif1i(>iilty.  Wlien  ferric 
chloride  vt  addvd  to  the  jialution  of  &n  ttcetste,  such  us  sodium 
acL-tiitc,  ii  blood-red  colour  is  pruductid,  owing  to  the  fornmtiou  i>f 
ferrio  acctaUi  (the  isalU  of  fomiic:  and  prupjontc  acidit  produce  the 
samo  reeult).  When  this  aolation  U  sutHciently  dilnt«,  a  brown- 
red  precipitate  of  basic  ferrio  ncoLate,  ^c  .ktl.*,  is  produced  od 

boiling,  acetic  acid  beiztg  liberated  at  the  same  time. 

A  vt'T)*  delicate  test  for  acetic  acid  is  the  formation  of  cocodyl 
oxide  (80).  Owing  to  the  extremely  poieouaue  nature  of  this 
BiibstAnce.  great  crare  must  be  exercised  in  applying  this  test. 
Among  the  acetates  of  techuical  im^jortance  arc  had  acttate 
("  augnr  of  lead  "),  dasic  lead  aceiatr,  and  aluminiwm  acetalt.  The 
first  two  are  used  in  tbu  luauufacturt;  of  white  lead,  aud  the  third 
as  a  mordant  in  caUco-priatiiig  (381). 


Butyric  Aoid«,  n,n,0,. 

90.  Two  ieomcrin  acide  with  the  formula  t^U^O^'aro  known. 
Thoyaro  normal  butyric  acid,  CU,-CH,'l.'ll,-C0OH,  and  isobutt/- 

rte  acid,  nir'>CH-CO0n.     The  constitution  of  these  acida  is 

proved,  by  their  sTiitheais,  the  normal  compound  being  obtained 
from  fj-jirfipyl  ifdidc,  mid  iho  ido-acid  from  isopropyl  iodide: 

0H,.CU,CIl,l-^CU.OH,-0H,CN-»CU,-t;iI..Cil,COOH. 

CH. 


^^•>(;hi— [;^>cu.cN. 


'CH 


»>cii.coou. 


The  normal  compound  ia  nlao  called  femimtaiion  htityrie  acid, 
from  the  fact  that  it  can  be  obtaiiitid  by  the  fermentation  under 
certain  conditiouo  of  mc\\  substances  im  sugar.  Jt  baa  an  extremely 
disagreeable  odour,  and  can  only  be  oxidised  with  difficulty. 

Butter  uontoiiM  aboin  -l-rij  of  /i.butyric  aci<l.  along  wilh  smaller 
qnnaltUes  of  older  volatile  iK^iils  of  the  fatty  serie*,  imi?ili  aji  eaproTe 
aold.  Tlieee  ara  probably  [in^di^iil  iu  itiu  form  of  i»ton.  Since  *'  volt' 
tile  fatty  acids"  are  not  ahiaimil  by  fiflponilicatinn  of  other  fata, 
wheitier  animal  or  vegetable,  llitir  prfseiico  fiimiahes  the  moat  char- 
aoWrisliedlstiiielioii  Iietween  butter  niKl  mnr^Krine.  wliiLhisamiiiare 
of  animal  aud  Tcgi'lnblo  fats.    Knee  the  ])ercenin^  of  vulatite  fatty 


I 


r 


MrCHER  FATTY  AaOS.  top 

\  acids  m  butler  ia  uul  a  voasUiit  quanlitj',  but  may  vary  between  vride 
liiuils.  It  is  Imposslblfl  in  oBrtsii]  cases  to  idenlify  a  mixture  of  batt«r 
andraargarin«b7adet«riiiinatiflnof  llin  amountof  the»«  acidApreaenC. 
By  the  applicalinn  of  other  IgsIs,  it  is  Hometimoii  pontble  to  obuun 
Rliabla  results  iu  doubtful  canes. 

Isobutyn'c  acid  aluo  ha>i  a  TerydiRiigrc'T'jibli?  itmi?]l.  It  h  a  com- 
pound contiiining  a  tRrtmry  hydrogcm  atom,  and  experience  liaa 
shown  that  such  compountlii  arc  very  caalj  oxidized,  so  that 
oxidation  atTords  a  method  of  dietinguiahiiig  between  tlie  nornml 
ndd  and  tho  iso-acid. 

Th«  culciam  salts  of  thoM  acids  also  oxbibit  a  nmikrlfflblo 
difference  in  properties,  thnt  of  the  normal  acid  being  lo'8«  soluble 
in  hot  water  thnn  in  cold,  while  that  of  tho  iito-acid  follows  the 
ordinaiy  mle,  and  is  more  goliihle  in  hot  than  in  cold  wnter.  A 
solution  of  normal  calcium  hiitvratc  saturated  at  0°  deposits  con< 
eidenible  quantities  of  tho  salt  when  heated  to  about  80^ 

In  accordance  with  tho  principle  of  mobile  eputidriutn  ("In- 
organic ChemiHtrj-,"  288),  normal  calcium  butymtp  should  disaoWe 
in  water  with  sliglit  evolutiou  of  boat,  tind  tho  cnlciiim  salt  of 
isobntjTic  acid  with  slight  abeorjition  of  heat.  This  view  is  fully 
supported  by  the  rcsalta  of  experimeat. 

Eighsr  Fatty  Acids,  CdH,„0^ 

91,  Uany  of  these  occur  in  nature,  chief  among  them  being 
paJmitic  acid,  C„II„0,,  and  gttaric  add,  C„H^O,,  both  of  which 
oont4iin  normal  carbon  ohairui,  as  will  he  Hhown  later  (144).  They 
are  fonnd  in  very  large  quantities  lui  esters  of  glycerol  (1&9), 
being  the  principal  conntituent  of  most  animal  and  vegetable  fats. 
They  are  obtained  from  these  by  Baponification,  a  process  carried 
out  by  heating  either  with  slaked  lime  (101),  or  with  concentrated 
sulphuric  acid.  Sulphuric  acid  causes  slight  carbonization,  with 
tho  n^iill  that  tho  ftitly  tmds  Imvo  a  d&rk  colour  im])itn<id  to  them. 
Thoy  coo  be  purified  by  dietiliation  with  superbeated  tuenm.  By 
sapODtfloition  of  fats  in  this  way,  a  mixtnro  of  fatty  acids  is 
obtained,  which  is  semi-solid  at  ordinary  lemperaturoB.  It  eon- 
tains  the  two  acids  mentioned  above,  which,  when  pure,  melt  at 
62"  and  69°  respectively;  when  mixed,  each  lowers  the  melting- 
point  of  the  other  (14),     Moreover,  the  liquid  oleic  acid,  whtoh 


I  to 


ORGANIC  CHEMfSTRY. 


belongs  to  auotLer  homologouti  Kcrivs,  \t  &I0O  pni«cut;  it  au  be 
pressed  oat  of  the  mixture,  Icaviag  a  vhitu,  solid  aubstouco  used 
in  the  inaiiiifiinturo  of  "  stenrine"  cnndles.  For  this  purpose  it  la 
molted,  and  a  little  pumlUTi  wax  added  to  prorent  tlio  crj^lalliza- 
tiou  of  the  fatty  acidB,  whiith  woald  make  the  caudles  very  brittU: 
the  molten  miiRs  iR  then  pounMi  into  moulds,  in  the  middle  of 
which  wicks  are  fastened. 

Houfs  are  the  alkali-ttalts  of  the  fatty  acids.  The;  are  prepared 
by  siipoiiifying  the  fata  with  solutions  of  caustic  soda  or  cauBtic 
potniih  heated  to  the  boiling  ti-mpfrnturc'.  The  potassium -soup 
is  oalled  "soft  «oap,"  uud  UHiiiilly  had  u  yellow  oolour.  In  nnme 
countries  the  colour  in  changed  to  grcou  by  the  addition  of  a  little 
indigo,  the  aoap  heing  then  known  aa  "grueii  aoap."  I'otaeaitim- 
HOup  roDtainii  not  only  the  potaseiiim  salt  of  tin;  fulty  aeid.  but  ul«o 
the  g]yccrt>l  produL'cd  in  the  reaction,  and  a  considerablu  propor- 
tion of  wat«r.  Sotlitim-flonp  is  hanl;  it  is  Aeparstei  from  the 
reaction -mi  stiire,  after  saponilicatitm  is  pomplele,  by  "  salting-out," 
which  conRiKtii  in  the  addition  of  <_'ommoii  ndt  in  the  solid  state  to 
the  mixture  at  tho  boiling  tvmprrnturc.  Htnce  the  sodium  i<nlt  of 
the  fatty  acid  is  insoluble  in  »  cuni^outruted  solution  of  eodium 
chloride,  it  sepaiittcs  out  in  tho  molten  EtAtc,  forming  n  layer  on 
the  Biirfttfle  of  the  brine.  The  glycerol  remains  dissolved  in  the 
hittvr;  tho  sonp  obtninod  in  this  way  ennsistA  of  tho  sodium  salt 
of  the  fatty  acid,  together  with  a  small  percentage  of  wat«r. 

9^  The  cleAHsing  action  of  soap  msy  be  explained  in  the  fol- 
lowing way.     As  early  aa  the  beginning  of  the  nineteenth  centurr 
it  was  pointed  out  by  Cheveeul  that  when  au  alkali-aalt  of  one  of 
the  higher  fatty  acids  is  bronght  into  contact  with  a  large  «x( 
of  watci*,  it  de'^ompuses  with  foTmatioii  of  free  alkali.     The  Mid] 
thus  libonited  unites  with  u  second  molecule  of  the  salt,  fomiin^l 
an  insoluble  substance,  which  with  the  water  produoes  the  lather. 
The  presence  of  free  alkali  in  dilute  soiip-soltitioiis  can  be  readily 
shown  a»  follows.      A  coni^vntnittid  soap-solution    is  only  verj 
slightly  coloured  by  phenolphthalu'fn;  but  the  addition  of  a  largtti 
quttDtity  of  water  causes  the  development  of  the  red  colour,  du4 
to  tho  action  of  the  base  thus  liberated  on  the  phenol phtbalem. 
Tlio  MiJip  has  tht'reforc  undergone  hydrolytic  dinsociHtion  ("In- 
organic Cbemtftry,"  239),  owing  to  the  weak  acid  propertios  of 
the  higher  fatty  adds. 


ACTIO!-/  OF  SOAP. 


Ill 


Thft  suiliuK  of  ttic  akiu,  clothing,  etc.,  is  nsiially  ilue  to  suh- 
etiiiK-ia  ol  tt  fiilty  iiaturu.  Wleu  a  fat  ia  brought  into  contact 
vith  an  ulkatiue  liquid,  and  tko  mlxtare  abakcn,  »  part  is 
saponified,  and  dissiolvea.  Thfi  ffrentcr  portion,  howftver,  roinaina 
8nBpen(lc><l  in  the  li(|Uiil  in  the  form  of  iiiinnte  dropK,  which  givv 
it  a  milky  Rppeamnrp.  Tht*  product  in  cal\m\  an  pmulsiou.  The 
alknli  lihenited  from  th»  soap  has  therefore  both  a  Kaponifying  and 
an  eniiilfiifying  action  on  tito  mibtttanru  to  which  the  noiiing  ie  due. 

If  tho  corrcctuoi^s  of  this  (.-xplunution  in  admittod,  ttiu  (|Uciition 
arises  as  to  wliy  (roe  alkali  eh<>i!ld  not  bo  Uicd  inati'Jid  of  soap  for 
wu^biiig-piirposeii.  It  ia  fwi'iuitto  tho  use  of  eoap  provonte  thp  pros- 
cues  of  an  oxcessiii'o  proportion  of  free  alkali.  Tho  proportion  of 
alkali  libenttcd  from  «oap  ia  small  uHth  a  iiinall  quantity  of  wat«i',  and 
large  with  »  large  qnivntity.  nut  the  addition  of  a  large  quantity 
of  water  doea  not  very  much  affect  tho  concentration — the  amount 
of  free  alkali  in  unit  volnme  of  liquid — since,  although  it  prodocea 
mtirh  froti  alkali,  it  ^tmullaueously  dihitua  tt.  Tho  use  of  soap 
ha«  therefore  tho  effect  of  automatically  regulating  the  amount  of 
ttve  alkali  prcSfut  in  thf  watL-r,  and  ki>i^ping  the  solution  very 
diluto.  Tliis  would  not  be  the  case  if  free  iilkuli  W4.'re  employed 
iu^teftd  of  soap,  and  the  hitter  poKseascs  the  fiirthtT  advauUigci  uf 
formiog  a  Lather,  whicli  takes  up  tho  dirt  and  facilitates  its 
removal. 

When  water  contains  a  certain  percentage  of  calcium  salts,  it 
i«  said  to  be  hard  ("Inorganin  Clieniigtry,"  269).  Sueh  water 
docs  not  lather  with  soup,  but  raiises  the  formation  of  a  white, 
floccnlcnt  eubfltiuioo.  iK)nKifitiiig  of  insoluble  calcium  paltg  of  the 
fatty  acidK.  Hard  wuti>r  is  thcrcfuru  uiisuitablo  for  wai;hing 
boeauee  it  proventK  ilie  formation  of  a  lather,  and  aUo  because 
the  alkali  combinej  with  the  acid  of  the  calcium  salts  (miiphate 
and  oarbonate)  prc«ent. 


Electrolytic  Dissooiation. 

93.  It  18  fully  explained  in  "  Inorganic  Chemistry.''  65  and  68, 
vhy  motecnlea  of  acids,  bases,  and  ealt«  are  a&sumed  to  split  up  in 
Hi^ueoiici  Aolniion  into  partick-s  called  ions,  (charged  with  oppooiie 
kinds  of  electricity.  In  such  a  solution,  an  acid  is  cither  wholly 
or    (>irlly   split  np   into   positively  charged    hydrogen   ions,   H 


Ill 


ORGANIC  CHEMISTRY. 


(cuttoii^),  and  negatively  charged  anions:  for  acetic  acid,  H  (po«i* 
life),  and  (C,H,0,)'  {negatire).     Bases  yield  a  positively  cbargedj 
iQucalUc  ion,  and  a  negatively  charged   OU'-ion;  aalte  a  posi- 
tively charged  metaUic  ion,  and  a  negatively  charged  aoid-ndicle 
ion. 

tt  is  further  Btat«d  {IhuL,  M)  chat  in  the  solution  of  a  jurtlj 
ionized  huWuiucu  un  equilibrium  uxista  which  can  be  exprefticd  in 
the  case  uf  a  mauoli»sic  acid  by 

ZU^Z'  +  H, 

where  Z'  represents  the  acid  radicle.     If  v  ie  the  volume  in  litres 
containing  one  gniniino-moleculo  of  the  acid,  and  a  is  the  portion 

ionized,  then  the  concentration  of  the  ions  it  -,  and  that  of  the 


□n-ioniscil  portion  is 


1  -  a 


The  eqnation  representing  the  state 


of  eqiiilihrinm  in  the  case  of  the  above  example  of  a  monobasic 
acid  is  th^ireCore  {IbUI.,  4S) 


In  this  equation  it  is  oonstaut,  and  \i  called  the  ioHitalion  cotitloHf. 
It  has  been  ahown  that  this  equation  affords  an  exact  measnre  of 
the  amount  of  ionization  in  the  case  of  the  very  weak  orgamc 
acids;  tliat  is,  expresses  acoumtely  the  connection  betweeu  the 
dilution  tt  and  the  ioiiijsation  a.  For  this  reason  it  is  Cfdled  the 
Uiip  0/ dilution.  It  was  discovered  by  Ostwald,  who  dissolved 
one  gramme-molecule  of  an  acid  in  different  quantities  of  water,  v, 
and  n^certaine<l  the  ioniiuitions  a  by  a  determination  of  the  cleotnc 
condiictiTity.     On  eiibstitiiling  the  vahict*  ohlained  for  tt  and  v 

respectively  in  the  c^ipression  — :.  the  luttur  wus  always  found 

to  have  the  same  va]ae,  as  it  mual  if  h  h  cousiant. 

As  the  constant  is  a  very  small  nnmber,  it  is  usual  to  multiply 
it  by  100,  iiTul  to  denote  tliirt  qiimility  by  A',  so  that  A*=  KhU^. 

The  Hccuracy  of  this  law  will  be  seen  from  the  examplve  in  th« 
following  table: 


IONIZATION  CONSTANTS  OF  THE  FATTY  ACIDS. 


««3 


AMUe  AMA. 

Fropienw  AcU. 

n.Buijiio  AiHd. 

w 

lOO* 

lOOb 

V 

9 

]<»a 

lODt 

V 

lOOa 

lOOb 

8 

t-tw 

0-00190 

i-oin 

o-ooiao 

8 

]-(H8 

0-00144 

IS 

1-678 

0-00179 

10 

MM 

000194 

te 

i.ri;i6 

l>>(M>iau 

8S 

3'8W 

0-0ai8'3 

83 

a.Offlt 

0-00134 

3£ 

2-l«-'V 

U-OOliO 

«t 

8-38 

0-001711 

0-1 

2-t40r> 

0  OOlSS 

U 

S-OAS 

0-001» 

IStt 

4-68 

0-0017» 

12tt 

4-Oi 

O-OOISS 

198 

4- £09 

0-OOlM 

lOU 

tS-H 

0-00177 

lOU 

10-78 

0-00136 

lOW 

11-41 

0-00144 

Fom  ic 

AcMic 

Prr^pioaie 

n-ButjTiG 

Valeria 

Acid. 

Ackl. 

Add. 

Acid. 

Acid. 

)-02U. 

0-OOlt), 

0-0013, 

0-0016, 

0-0016. 

^V         M.  The  property  of  ttcids,  iwaaUy  called   their  "Htrength," 
depends  npon  their  d«gre«  of  ionization,  strong  acnds  uiiderjj:omg 

■  consiUeniWe,  and  weak  ai-ids  but  iJight.  ionization.  Since  the 
constant  A'  rises  or  falls  in  valuu  HimultiiiicouKly  with  it  und  in 
independent  of  the  conceutrution,  it  affords  a  fiouveiiieut  mcaaure 

I  of  the  Etrength  of  an  ucid. 
TJm  following  abowa  the  valno  of  ff  for  certain  fattr  aoida: 
It  will  be  noticed  tliat  formin  acid  has  a  greater  value  for  K,  and 
is  therefore  stronger,  than  its  hntnologuL'E,  u  fact  which  oiltirtlB 
anolber  example  of  the  diScrouco  iu  properties  existing  botwoon  it 
and  the  other  members  of  tlut  series. 
A  CO neid oration  of  tho  degrees  of  ionization  for  o()iial  eone«n* 
trations  shows  that  these  acids  are  rery  weak  cempared  with  strong 
tniiienil  acids  like  hj-drochloric  and  Hulphuric.     When  y  =  16, 
^^th«n  for  hydrochlorin  acid  100«  =  *ih-ho,  and  for  acetic  acid  only 
^K2  •  073.    it  is  obrious  tliat  lOOw  is  the  amount  ionized,  cxpresfcd 
^^in  percentage. 

Allliough  the  law  of  dilution  ia  genemlly  n|iplical>le  to  the  weal: 
organic  acids,  it  A<ka  not  bold  good  for  the  sirauK  mineral  ncida.     ll 
ban  not  yet  b«eD  possible  to  giro  a  perfectly  satisfactory  ex[)lauatkin 
F  tliispheiiouuinuiu 


DERIVATrVES  OF  THE  FATTY  ACIDS   OBTAINED    BY 
MODIFYING    THE   CARBOXYL-OROUP. 

96.  The  riirboxfl -group  may  be  nindilicJ  by  the  exolutage  of 
its  oxygpn  atoms  or  hydroiyl-group  for  other  ulumonta  or  {iroiiiM. 
Tbia  ia  th«  cue  iu  the  cImsm  of  compounds  dcacrjbed  in  thU 
section. 

I.  Acid  Chlorides, 

These  are  derived  from  the  acidii  by  ropluccmDiit  of  the. 
hjdroxyl-grniip  by  chlo^nr^  oo  that  they  eoiiUiin  the  fcroup 
— COCJ.  They  aro  obtained  from  tho  aoids  by  the  notion  of  the 
chlorides  of  pbosjihorus,  PCI,  and  PCI,,  or  of  phoephorus  oxy- 
chloridf,  POCl,: 

ac»H.„ . ,.  coou  +  PCI,  =  3c\n„ .  ,-coci  +  P(0U),. 

T\ie  eauv  witJi  which  the  acid  chlorides  aro  ooDV(>]-ted  inli)  the 
corruepoiidiiig  acids  i»  a  proof  that  the  chlorine  atom  has  rt^plaoed 
the  hydroxyl-gronp.  In  the  case  of  the  lower  members  this  can 
be  effected  by  merely  bringing  them  into  roiitart  with  water.  If 
the  oldortne  atom  had  entered  the  alkyl-gronp,  this  would  not 
take  p1a4-c,  becauae  an  alkyl  chloride  Is  uot  decomposed  by  water 
at  ordinary  tvnijwraturea. 

The  acid  <^'htoride(i  uf  this  oerieii.  at  least  the  lower  membeni, 
are  liqnlds  with  a  ouffocHting,  irrituliiig  odour.  The  chloride 
corrcBpondinir  to  formic  ucid  is  iioi  known.  A(xtifi  chlnruh, 
C1I,C(>(.'1,  fumes  iu  tho  air.  aud  can  be  distilled  it-ilhunt  Oecom- 
position.      It  boile  at  ftS",  and  its  spcoifio  grarity  is  1  •  13  at  0^ 

The  acid  chl"ri<icit.  especinily  aootyl  chloriOe,  nr«  of  gjMt 
service  in  delerniiniiig  whether  organic  compounds  contain 
hydroxyl,  becaoite  witli  mich  compounds  they  yield  aeetyl-deriw 
tires.     In  this  way  they  react,  with  alcohols,  forming  esters: 

RO|ir+^i|0CCH,=  RO0C-CH,4.HCl.      , 

The  compound  in  which  the  presence  of  hydrosyl  is  suspected  ia 
tested   by  sllowing  it  to  remain  for  some  time  in  contact  with 

■  14 


AaO  ANHYDRIDES  AND  ESTERS. 


>»5 


acetyl. chloride,  either  at  the  oriiinary  temperature  or  ntiiler  the 
influciico  of  slight  heat.  To  aeccrUin  whether  an  acetylHMm- 
pound  hu  been  formed,  the  product  is  subroittfld  to  analysis,  or 
is  Hiponifled .  tn  the  latter  awe,  the  presence  of  acetic  acid  proves 
that  an  acotyUderivnttve  was  proKent. 

Tlie  nuiil  cliIt)Ht!i-«  aIho  rvxcL  wilb  tliu  iiiercai>laiis,  with  lh«  forma- 
tiva  of  ncetf  iHjompoutiiU. 


XL  Acid  Anhydrides. 

96.  These  are  fonned  by  treatitig  the  iilknli>Kalt8  of  aoidii  with 


acid  chlorides: 


oc  cn. 


CH,-C0,C1  +  XaQ.OCCH,  =  0<^^;^J]' +  NaCI 


Higher  anhydrides  are  best  obtained  by  benting  the  aodiiim  salta 
cf  tbe  higher  acids  witb  acetic  anhydride. 

The  acid  chlnridea  may  ix*  liiokfd  ii|>rtTi  ao  the  mlied  nnhjdridci  of 
hyriroehloric  aoid  and  nn  iicid.  a  vinw  nhioh  tn  Hnjj|>i>rii-d  by  thiMr  for- 
mation from  tbcee  two  acids  in  pn»eiico  of  jibospharus  pentosidc  lu  a 
dehjrdrating-HRent. 

Mixed  Huhjdrides  of  tli«  fatty  Koidd  IheowolTes  exist,  aIthou(;h 
when  diiUilled  ili«y  d«4.!unipu«e  tiito  tlie  anliydridcx  of  ibe  two  acids. 

The  lower  memhera  of  this  series  are  liquids  with  a  disngreeahle, 
BufffMiating  ofloiir.  They  are  immiacible  with  water,  and  partly 
ou  this  account  decompose  but  slowly  when  in  contact  with  it. 
Aeeiic  anhydride  boils  at  137°,  and  has  a  specific  fpavity  of  1-073 
at  'i<y.  IJko  ncotyl  chloride  it  ts  used  in  testJDg  for  the  proeonce 
of  the  hyd roxyl-grou p.     No  nnliydridti  of  formic  acid  ia  known. 

m.  Eiters. 
07.  Thcee  remit  from   the  interaction  of  acid  chloridefl,  or 
anbydrides,  and  alnohols ; 


CII,-CO[Cl-f-H|OC,H,  =  CH,-COOC,H^  +  HCl. 

They  arc  also  formed  by  direct  trontment  of  the  alcohol  with  the 
acid,  although  extremely  slowly  at  ordinary  temperatures: 

tai.-COUli  -f-  HOC.H,  =  CH.-COOC.H,  ~r  11,0. 

The  speed  of  the  reaction  U  much  increaiiod  under  the  inflneQCO 


Il6 


ORGAMC  CHfMtSTRY. 


of  heat.     Kiitf>r)t  nm  further  nbbiitied  h\  acting  upou  iho  silrer  snlt 
of  nil  noit]  witli  lui  ulkyi  iodide. 

Tbe  following  is  a  rlianirt«nstir  aud  fretiuenti;  used  mothtM) 
for  the  preparation  of  thoce  compounds.  Dry  hydrocfaloric-acid 
gas  ia  led  through  n  mist iirc  of  absolute  alcohol  und  thi>  iinhyd  roiiK 
orgiuiic  auid.  Aft«r  fioiiiu  limi-  itic  rwictiuii-mixtiire  is  puur<*d  intu 
■watyr,  whereupon  the  esier  a>pnrat«  out.  owing  to  Its  slight  sohi- 
bility.  Thv  fonuuUoii  of  csti*i-«  iii  ihi«  wity  may  be  cxjOairied  on 
the  luisuinpLioii  thut  a  vt;r>*siiiull  ijUitiiiity  of  the  hydrocliloiic  aoiil 
anite«  ivith  the  organic  mid,  walvr  being  eliminated,  and  a  niinulo 
quantity  of  the  ofid  rhlortdo  formed  : 

cii,.coon  +  iici  =  cn.-coci  +  h,o. 

It  is  true  that,  for  cnoh  moleciilo!  of  acid  eliloriilo  formed  in 
a(?c(>riiano«  with  thiri  r(|Uatimi,  an  4.<(|UivuIcnt  <]uaiility  of  walei  U 
produced,  Kuftioieiit  to  leuonvert  the  chloride  into  the  acid  auil 
hydro<rhl(>ric  a<nd.  Thtre  is,  howrvci.  such  an  infinitely  grpntci 
numbur  uf  molecules  of  alcohol  than  of  water  with  which  llu- 
chloride  can  react,  that  tlui  pro&aitiUiif  of  the  fortnation  of  an  est«r 
h  very  much  greater  than  that  of  the  regeuor&tton  of  the  acid. 
Thid  i^ttito  of  thiugd  ootitinnca  lu;  long  :i«  the  unioiint  of  nk-ohoi 
present  greatly  i>xcc-oiU  that  of  the  water  formed;  it  ie  mado  to  do 
80  by  diu^otviu^'  the  orgiiuiu  iicid  In  »  tuige  oxce^  of  alcohol,  when 
the  object  iti  to  obtuin  llio  niiiiiimiim  >ield  of  ester.  The  forma* 
tion  of  esters  is  calle<l  ealerijtcalion. 

The  esters  are  colourless  liquids  of  neutral  reac^tlon,  aad  do  not 
mix  vith  water  in  till  proportions.  Thoy  are  lighter  than  wHt4?r, 
moat  of  them  having  a  BpuciHc  gravity  between  O-SaodO-U. 
The  majority  aru  churaL'terizeil  by  the  possessiun  of  8  vtTj  agree* 
able  odour,  resembling  that  of  fruit»,  a  fact  which  finds  practical 
application  in  their  employment  in  the  manufacture  of  fruit 
esscncee.  For  example,  iMami/l-iaavitleratc  {li.P.  ViC)  has  iin 
odour  of  apples,  el/i^l  butyrate  (11.1'.  121°)  of  pineapple,  add 
imamylacettUf  (B.T.  148")  of  pears,  ami  bo  on. 

Tertiary  nlcnliol«    cnii   easily  )k>  ityii  [luwizoil    fMCH   llio  ostofS  by 
means  of  GftiOKAHO's  alWyl-magnL-siiim-lialo){on  compuuiids  (BS): 

.OMgBr 

AililUiiin>protluac 


THEORY   OF  HSTF.RIFICATION. 


117 


The  uddluoii-praduct  ao  obluiued  nMiota  with  h  bocodU  molecule  or 
the  mitgneRium  cmnpoiitMl: 

/OMffBr  /OMgBr 

DecomiiMitiuti  wiili  water  then  yields  the  lertinr;  alcohol : 

.OMgUr  yOH 

K.C^H"         +  H,0=  UC^tt"  +  MgBtOH. 

R.  If.  and  R"  =  alkyl. 

98.  The  furmaliou  of  esters  bus  been  oarefully  invoitti|^ted  1>y 

Mveral   chemists,  first  of  whom  wi'fp  BKitTHKLuT  and  PfiAN  de 

St.    GiLLES.      Tlieir   researL-hts    have  sliowu    that    the    reactiou 

betwvvn  the  lu^id  and   the   aleohol   ia  nevur  complete,  eomo  of 

botl)  romaiuing  uncombiucd.  110  mutter  how  luug  tliv  [irocceit  has 

been  carried  on.     When  equivalent  f[UiuititiuB  u(  u«etic  acid  and 

ethyl  alcohol,  for  examjilu,  ure  UKed,  the  llnnl  product  tu  such  that 

fmm  each  gramme-inoleculo  of  ideohol  and  arid  used,  only  two- 

thirdit  of  a  gramitie-moIei.-tile  of  nil  ester  and  of  water  are  formed, 

while  one-third  of  a  gr&mme-mokcule  of  the  alcohol  and  of  the 

Htric]   rpBpectively  n-'raaia  iincombliicd.     The  name  limiting  point 

is  reached  whon  an  estor  and  wat«r  are  brought  into  contact  in 

cqnivixlent  quiiTititica.     A  state  of  f^qiiiiibrium  is  nltimatoly  rfiiehed 

Ixtlween  the  four  i^iibstaucos,  alcohol,  a<!id,  OHtor,  and  water,  due 

to  the  rwersibility  of  the  reaction  ("  Inorganic  Cliemistr)-,"  48). 

It  may  be  repreHonted  as  follows: 

c.u.on  +  oHjCoou ^ on.cooc.n,  +  h,o.  - 

The  eqnation  of  equilibrium  dodured  in  Ihid.,  40  and  50,  may 
be  applivd  to  the  formatioa  luid  docompoeition  of  caters.     It  is 

X-(;»-x)(s-a!)=i'a^.     or     (;.-:£) (5  -  i)  =  JTx". 

where  ^  \s  the  conoontratiou  of  the  alcohol  in  the  first  iiietaiico, 
and  q  th*t  of  the  acid,  while  x  represents  the  quantities  of  water 
and  of  estor  re«pootively  present  when  the  ntaLe  of  rrgnilibrhim  is 
attained.  ^Vll  these  tire  eiproBBeil  in  },rninime-mole(nilns.  and  A" is 
ft  constant.  There  are  here  two  reactionB,  with  itpposite  elTectB, 
biking  plitce  siinnltaiieouiily,  so  that  all  the  BtaiemcnU  already  mode 


iiS 


ORGANIC  CHEMISTRY. 


{Ibid.)  are  equally  ajiplicubtc  iu  the  presont  instance.  Whenp,  q, 
auci  A'  are  knowu,  the  uiiknowu  i]i)aiitity  z  may  be  calculated. 

NuiDcrnuaobscrvntiona  have  proved  that  A'ia  iqunl  t«  0'3-*  fnr  ibo 
Rj'stfim  otliji  alcohol  +  acelio  acid.  When  one  granime-inolecuic  of 
alciiliol  (46  g.J  M)d  one  i;raLuni«-iii»leoule  of  aoeiio  acid  (flO  k-)  are 
bruiight  ItiU)  cotiUtct,  m  tlila  <^i«  bnili  /'  niid  9  bctng  equaC  to  1,  tbe 
equation  is 

(I— *}'=0-25*\    or    «»  — |;b  +  J=0, 
from  nhioh  it  follown  that 

«  =  |. 
It  follows  (bnt   ihU   lyatcm  in  the  atalo  of   eqnllibriiiia  «onUUns 
i   (;nimtnu-moleaul9  a3oobo1  +  i   grHmme-molecult   acetic    add    -f 
{  j^amme- molecule  water  +  f  graniQio-iaoldcuJc  esler. 

99.  Several  deiluctions  can  be  drawn  from  the  equation 

{p  -  x){q  -  x)  =  K:^, 

whii-h  ha^l  b(>en  oBtaliliEhed  by  experiment  lung  previous  to  theee 
tbeoretieal  dert-lopiDuuts. 

1.  The  c«U;rili<:al,iou  \s  approxiitiutvly  ijuuiititativc  tmly  when  a 
large  vxvves  of  the  alcohol  is  miavil  with  a  very  small  quantity 
of  Ihtt  acid,  or  when  a  siuaU  proportion  of  tlie  alcohol  is  bn>ug;ht 
into  (intact  with  a  Inrf^c  amontit  of  the  acid. 

Putung  the  equation  in  the  form 


X 


=  A' 


q~x: 


it  is  crident  that,  tho  qttnntity  of  tho  alcohol  [p)  heing  infinit^dy 
great,  tho  right-hand  side  =  00 .  This  holds  good  when  q  =  z, 
that  \i,  when  all  this  acid  has  been  Roiiv^rtcd  into  «Kt«r.  It  is  also 
true  wlii^n  thf  ratio  of  the  quantity  of  acid  to  alcohol  Is  infinil«ly 
great,  the  wKolo  of  the  alcohol  changing  into  CKter. 

S.  Tho  alool^ol  and  the  acid  cxorcigc  tho  sumo  inflacnco  on  Iho 
fonnntion  of  eaters;  that  is,  if  one  mixture  is  made  containing  11 
certain  miniber  of  acid  moli^piiloH  and  »  times  as  many  nlcobol 
molecules,  and  another  iu  which  the  proporiioQS  of  acid  and 
alcohol  are  rcTcrsed,  then  the  number  of  molecules  of  acid  con- 
rerted  into  ester  in  the  firtit  rn»c  is  oquol  1k)  that  of  the  molecules 
of  alcohol  converted  iu  the  second. 


When  p  grnminc-moleculog   of  alcohol   uro   mixod    with   np 
gram  nie> molecules  of  acid,  th«  ec]natioQ  becomes 


HjuT«rsely,  when  np  gramnie-moleculMi  of  alcohol  are  added  to  p 
^Kgramme-molacules  of  acid,  we  have 

BSnt 


•X  up  —  z 


r  fi  —  x' 


■r, 


< 


:iit  thoGe  two  efjuatioDs  aro  identical,  the  Qrat  being  oonverted 

into  the  Becond  by  maliiplying  acroM  by  ~ . 

3,  The  addition  of  a  quantity  of  the  ester  to  tlie  mixture  of  the 
alcoho]  and  the  acid  at  tlie  beginning  of  the  experiment  has  the 
s&ine  effect  on  tlie  formation  of  eeter  as  vroald  be  exerted  by  an 
«qniTa)ent  <(aantitj'  of  water. 

When  J"  gram me-niolec'u lee  of  water  or  of  eeter  are  added  to  a 
ixlure  conlaiuiiig/j  gramme-nioleculesof  alcohol  and  q  gnunme* 
olecules  of  acid,  then  in  both  caaea  the  equation  becomes 

(p-x)(q-x)  =  Kz{x-\-r). 

lows  from  this  that  the  equilibrium  is  influenced  to  the 
ie  extent  by  the  addition  of  water  and  of  ester  in  equivalent 
qnantiticB. 

100.  A  typical  application  of  iha  principle  of  mobile  ctiui- 
Itbriuui  {  "Inoi^unic  t'liuniiatry,"  !J35)  umy  be  iniidc  in  tlie  caw; 
of  the  formatiun  of  eaters.     Although  (he  velocity    of  formuttoii 

<i  dc-coRipocition  of  estci-s  ilepciitia  grontly  upon  the  teroporaturn, 
change  iu  the  latter  hus  but  vt^ry  slight  otToct  upon  the  equi> 
libriom.  At  10°  the  limit  of  esterilicalion  h  6fi-2<(,  at  220°  it  is 
Ol)*fi.<.  In  acrordunct'  wilii  t!i<-  principle  jiiNt  natntioned,  tliiii 
.traold  not  Iw  the  ciia»  unless  the  lieuta  of  formutiuu  of  the  BStera 
ere  rery  small.  That  they  actually  are  so  haa  been  eatablished 
ij  experiment. 

101.  The  saponification  of  pgtere  nndt'f  tho  influence  of  acids 
takea  jilace  in  accoTxIance  with  the  following  equation: 

CH.-COOC^,  +  IL,0  =  C]1,-COOH  -f-  C.H.OH. 


tao 


ORGANIC  CHEMISTRY. 


The  octiou  of  tlip  acid  which  is  here  added  ia  Uierefore  only 
catnlytic.  U  may  tliuH  be  iiotcd  that  the  preeenoe  of  miuoi-ol  acid 
only  Hccc1omt««!  tho  e:\potiitlcatioD,  oJid  that  the  same  result  would 
W  obtainod  witliotit  tliie  ticid.  Uioiigh  in  a  sjiace  of  time  iuconi- 
pHr»h1v  longer  (68}.  If  tlie  conceutralion  of  the  ««t«r  be  C^,  tluit 
of  the  water  be  C^ ,  and  x  the-  quantity  of  e8t«r  which  baa  nudorgoiie 
aapon  ill  cation  during  the  lime  t,  then  the  reloci^  of  wponitlca- 
tiou  for  each  moment  can  be  repieaeuted  by  the  equ'atioo  for 
bimolccalar  reactione  ("Inorganic  Chemiatry,"  60): 


ilz 
df 


=  kiC\-^)iC,-x). 


a) 


If  Ihe  G«t«r  is  dimolved  in  a  very  large  quantity  of  water,  the  con- 
ccDtrutiun  C,  of  the  wnli'r  ig  only  very  8llghtly  altered  by  the 
saponitication,  HU  th»,t  it  may  be  included  ia  tlio  constant.  The 
equation  ia  theroforo  fliniplilieil  tn  that  fora  iininiolecular  reaction: 


=  k,(C  -  x). 


(2) 


The  saponitlcatioD  of  eatera  by  bases  may  be  repreaenteil  as 
followa: 

CH,.  COOCail,  4-  NaOII  =  CH,-  COONa  +  C,UjOiI. 

Since  iu  this  cane  the  reaction  in  a  binKtlouular  one>  uquation  (l) 
hoMt  good  for  it. 

The  Tfilocity  of  fiaponiflcation  of  Mter«  by  acids  dependB  laigvS|:j 
on  the  partirnlur  one  ii»otl.  With  stroikg  acidii  tiie  proccsa  ill 
rapid,  and  bIow  trith  weak  ones.  It  has  been  thown  that  the 
Telocit}' of  HapotkificiLion  in  conditional  upon  the  amount  of  elec- 
trolytic diiMnciation  ot  the  arid  employed.  Frnm  this  fact  it  may 
be  cotieluddl  that  the  aitponifyin^  action  is  due  to  the  bydrogeo 
ion,  eince  tbis  is  common  to  all  acids.  The  velocity  is  very  iimch, 
greater  for  bftsan  thiin  for  iiciil^  ;  thii£,  for  dilttto  (dccinormul) 
kolntioDs  of  eauKtio  potash  and  hydrochloric  acid,  the  ratio  of  the 
velocity  conHtjtnts  K"  fur  the  uipDiiiticntion  of  mrithyl  acetate  h 
1360:1.  The  velocity  of  saponification  in  the  case  of  Imma  aldo 
depends  upon  thoir  electrolytic  dieeociution.  Ammonium  hy- 
droxide, for  example,  which  ie  eoiiiiiderubly  lc«8  ionized  than 
caiietic  potash  or  caustic  soda.  snpoaiScs  much  more  slowly  tli;in 


TmO-jtCtDS  AND  ACID  AMIDES. 


131 


y         coin 


die  latter.     It  a  therefore  tlie  hytlrosyl-ion,  oomraon  to  all  tlie 
buses,  wtiicli  csiiees  Mi[ionificalion. 

1q  the  t(.i:hi)i(:ul  fiaponiltciiiioa  of  f&ts  with  slaked  linte  (91)  a 
much  BmaUcr  luiiotint  of  tliia  bnso  is  uaod  than  the  equivalent  of 
llio  qiiuntity  ol  ncid  obuiinod ;  the  Bitponiflcntion  U  nevertlivleas 
coiii])lou>.  This  is  dtio  to  the  fact  ihni  the  higher  fatty  ucid^  are 
verjr  weak,  ia  consequence  of  vhicli  tlieir  stilts  undergo  psrtUl 
rol^io  diaaociation.  ThiiH,  notvrithetAnding  the  «:toe^  of 
id.  there  is  always  mnie  free  baae  (hjrdroxyl-ioiis)  preeeat>  bj 
which  the  eapouilicatioa  is  effected. 


Xtttrlllcttloii  at  Ttintxj.  SMandkrr.  snd  Ttitlarr  Aiooholi. 

lOS.  MKNitc-uLiTKiK  Liw  inveatigated  the  quantity  of  Mter  fomiDd 
when  primury,  sooondsry,  iiiii]  terliar>  alcoht^g  rcnpectivelf  arc  boated 
Willi  An  equivalent  quantity  of  a^ioua  acid  In  sMil«d  tubes  for  one  hoar 
at  154*.  He  haa  shown  that  tho  poroentagD-tmnibors  obtaineti  for  ail 
the  members  of  efteh  clasa  of  aloolioU  nre  nearly  the  Hamc,  althmigh 
ihpy  differ  wtilely  for  ihe  daaseo  Ltictiiaelvefl.  T>iii»  about  47*  of  pri- 
mary, about  a2«  of  wfloiidary,  and  only  about  l..Wo(  ivrliary  Atcrthots 
are  converted  iiilo  t»Ci'nt.  Thiit  afTonls  a  muiiua  of  determining  to 
wliieb  of  the  three  ata»>(«  a  givsu  alcohol  belun)^. 

IV.  Thio-aeiib.  R-CX)'SU. 

103.  The  thio-acida  are  frtrmied  l>y  Him  IntiraflCioa  of  aold  chlorides 
and  iMtaasium  aulpliydrate,  KSii,  a  mt^ihod  of  formation  whicti  is  a 
proof  of  tbe  ooitsiituiion  itidicnlt'd  aljove.  Tliej'  itre  liqttitls  nitb  a 
most  dfangreeablo  small,  and  when  heated  with  salts  of  faeary  tneiaU 
readily  yield  acetic  a^id  and  ttie  corres[>ondiiig  metallic  aalphide. 


T.  Acid  Amides.  ('Jl,n  ^i-CONH,. 

204.  Acid  amides  arc  forniuil  by  the  action  of  ammoiiia  on 
•ciJ  chlorides  or  unhydrideA.  a  method  which  atfords  a  proof  of 
Uieir  constitntioD : 


C,H,.,.-COp+H|yH.=  C,U,+.-CONH,-f  HCl; 
C,IIb.-,,-CO-^  f.   1    HiMH,  _  2n  ir        .C0\fL4-  H  f) 


Aeid  amidea  aiie  also  formed  when  tho  ammonium  »iU»:  or  tho 
fatty  aeidfi  are  Btronjrly  healed,  or  when  the  Bwlium  sails  iire  dis 


tffS 


ORGANIC  chemistry: 


[tUlod  with  ammOQium  cblonde,  one  moleoUo  of  VAt«r  1>«iig  iplif 
off: 

0„K,„ .  ,.C0l0lim,H;|  =  C„H,„  .  .-CONli,  +  11,0. 

It  has  alreadv  b«»n  m^ntiouod  (86)  th«t  when  tli6  nitrilos  uxt 
warmed  with  actdn,  two  molecules  of  wftt«ir  aro  tAlcoii  up,  with 
ifbrmation  of  tlio  ooiTespoiiding  iic'tilg.  This  rractioii  can  be  m 
mrriod  out — for  example  by  dissoliriug  thv  nttrile  in  concentrated 
sulphnric  acid^^thnt  only  one  molecule  of  irater45  added  on.  By 
thU  means,  &micle6  ar«  obtained: 

I  The  acid  amides  are  therefore  intermediate  products  in  tlje  con- 
Toraion  of  nitnleu  into  acids.  Amides  yield,  on  tbe  one  band, 
nitrileK  by  eliminatiou  of  wat^r,  by  distilling  with  phospborus 
pentoxide  for  example:  mid  on  the  other,  the  correq>onding  acids 
by  tuJditiou  of  the  elementB  of  water,  on  boiling  with  dilute  acidii 
or  ulkniis. 

Tbc  acid  amides  are  also  formed  by  the  action  of  ammonia 
npon  eaters: 


cii,.  oo|oc,H,  +  ii|Nn,  =  cti,-coNir,  +  c.h.oii. 


The  acid  amides  ore  solid,  crystalline  coDiponnds.  with  llie 
Exception  of /onwtfmu/e,  H-CONII,,  wliioh  is  liquid.  The  lowtT 
memberg  ar«  solublo  in  water,  and  odourlcsc;  when  pure.  Act- 
amiJr.  C1I,.C0NJ1,.  melt*  at  ifi",  and  dietild  at  222\  Some 
spcciuifiis  have  n  strong  odour  suggestive  of  tho  excrement  of 
mice,  due  to  eliglil  traces  of  impuriticB.  The  reinarkabty  liigh 
boiling-point  of  this  subatance  is  worthy  of  notice. 

There  iii  b  great  difTcrenco  between  the  behaviour  of  tbe  acid 
amides  and  tbe  aminoH.     Tbe  bond  between  carbon  and  nitrogen 

in  the  group  — C-<j-j,   of  the  anides  is  cosily  broken  by  boiling 

with  acids  or  alkalis,  whiob  is  not  tho  ease  with  the  bond  hetwcen 
carbon  «nd  nitrogen  in  the  nmincK.  Further,  tho  bnaa  pmiiertie* 
of  ammonia  are  greatly  weakenett  by  the  exc>iang8  of  one  of  iu 
hydrogen  atoms  for  an  arid  rudiclc;  and  although  aaitii  of  acid 
'  lonides  do  exiat,  they  are  decouipos^'d  by  water.  This  it  the  cftac, 
for  example,  with  acetamide  hydrochloride,  CH,-CO-Kn,HCI, 


AMiDOaiLOmOES.  MMOETHeaS,  ANO  AUmWES 

wlueh  i»  TormeU  by  pasaing  dr;  hydrochloric -acid  f^nA  through  sn 
otheKal  solution  of  scetainidc.  The  aoid  iiniidcs  even  {MttueHs 
acid  pro{iQi'titiS;  thuB,  an  nqtieous  sohition  of  acctumide  dis- 
solves luvreuric  oxide,   forming  u  compound  with    the  ff^miulB 

'Tlie  behaviour  of  tho  ainidos  and  aminuti  IowutUb  nitrous  uoid 
ts  analogous,  the  corresponding  acid^  and  alcohols  rospectiToly 
being  producwi  by  exchange  of  NH,  for  OH  (72). 

^H  The  nmittea  can  bo  convortMl  luio  tho  luniuea  witli  oii«  carbon 

^^^^HlOQi  l«flB  ia  (he  ido1«c«1o,  by  (roMitnei)i  with  bromioe  and  cnuatic 
^^^^ttooiaah^or  by  diBtilling  wuli  blL-aching-itowderand  aJalicd  liiix-.  ii  guod 
^^^^B  IBCtbod  of  pr^pnririK  the  primary  ninines  free  from  tbe  cnrrespDnd- 
^^^V  tug  secondary  And  tertiary  dcnvatives.  In  tbit  w»y,  htUyrami>ie, 
^M  OB.-CQ.-Cil.-OONn.,  yields  propylamim.  CIt,-CII,-CH,-Nii.. 
^1         The  theory  o(  this  rcaclion  will  be  expliunfid  IbIit  (S«). 

"  105.  In  addition  to  tliodt-rivativos  ulreodydcecribcd.  there  arc 
othort  which  cart  bo  obtain<Hi  from  tho  anids  l>y  substitution  in  tho 
oarboxfl -group,  some  of  which  are  doeerihcd  below. 

Amido^htorUita  are  formed  by  the  action  of  phoaphoriu  p«nta- 
cblortde  dei  the  ncid  Amides  : 

ROONII,  +  PCI,  =  K-OCUNII,  +  POCl,. 

is  aro  only  elablo  when  one  or  both  of  the  hydrogen 

df   An  amiiio-Kroiip.    NHi,   are  replaoed   by  nlkyl-rAdJcles. 

FKiey  yield  imiuo-olUvridta,   KCCI:NH.  by  tho  spUttiog  off  of  one 

tholeoule  of  HOI ;  Ihr  numv  compuuode  are  formed  by  lliu  addition  of 

HCI  to  ntlrlli>)>. 

Imitto-tthcrt  have  the  constitution  R-C^"  ^^,,,  derived  by  roplue- 

rffienl  of   tht^  doubly-linked  oiygen  of  the  c^arboxyl-group  with   the 
'loklo-fcrftiip,  Nil.     Tlivy  arc  obluioMl  by  combiiiatiou  of  alvolioU  and 
nUrlle*  und«r  the  Inllueuce  of  dry  byclrooblorio-iuiid  gas : 

fimino^UierB  form  wclUfirysiulluwd  fuitta  with  hydrochloric  acid, 
fliich  arc  eonvertwi  by  treatment  with  ammonia  into  the  hydro- 
chlorides of  the  amUUnta : 


'oc.n, 


■NU. 


,  The  amidioes  are  unstable  iu  the  free  &tate,  but  are  strongly  moot^ 
Ibaaic  aud  form  stable  salts. 


J 


134  ORGANIC  CHEMISTRY. 

Amidoximea  are  addition -products  of  the  Ditriles  with  hfdrozjl- 
amine,  NHiOH : 

R-CN  +  H.KOH  =  E.0<§2^. 

They  yield  aalta  with  both  acids  and  bases,  and,  with  an  alkaline 
solution  of  a  copper  salt,  give  a  flocculeut,  muddy-brown  or  green 
precipitate.    The  latter  affords  a  characteristic  test  for  them. 

Acidhydrazides  are  formed  by  the  action  of  hydrazine,  HtN — NHi , 
on  acid  cblurides  or  esters,  and  therefore  have  the  constitution 
R-CONU-NUi.  They  are  coDverted  by  the  action  of  nitrous  acid 
into  acid  azidet : 

R.OONH.NH,  +  HNO,  =  R-CON.  +  H,0. 

These  are  volatile,  explosive  substanceB,  some  of  which  flrystaUize  well 


/ 


AISEHTSES   AID   KETOIT^. 


106.  Tho  nldchydcrt  and   ketones  havo  tliu   general   formula 
.0.     Thpy   are  formed   hy   the  oxidation  of  primary  aud 
l»ry  alrohoU  rcspiHitivcly.     Both  ihwe  classes  of  alcohols 
hare  tlic  general  fonnuju  C„il,B  .  ,0.  wi  timt  the  itactiou  m  each 

»C(Wq  consists  in  tho  rcmoTal  vt  two  hj'drogcu  atoms. 
On  farther  oxidation,  the  aUiohydos  take  np  one  axygt;x\  fttom, 
forming  tho  eonwpondiiig  ncids  oontainirg  the  name  nnmhor  of 

■  carbon  atomn.  Thng  C„H,nO  in  ronvortpd  into  CoH^O,,  to  that 
•n  nldehyde  it  an  intermediate  product  in  the  oxidation  of  an 
alcohol  to  an  acid : 


f  .,H,„ .  ,0  - 

CrtiUKry  Ak-uliiil 


(■Ji„.o 

AliEpljyilr 


ojr„o,. 

lUKI 


Aak 


The  constitutional  formula  of  a  primarr  alcohol  ii  OcH^  ^ ,  •  OH,01I ; 
mi  oxidation  thin  yieldn  an  afid  CnH,u ,  ,-COOH.  Sinoo  the 
aikyl'gnniji  ('„H,„.,  iK  not  altered  in  thU  reuction,  it  must  he 
present  in  the  aldehyde.  Hence,  it  follows  that  the  two  hydrogen 
atoma  removed  from  the  alcohol  by  oxidation  must  como  from  the 
.gronp— CII.OH. 

There  ftill  remain  two  poBBibIc  structural  formula), 

RC<2'    »nd    RC— on, 

,of  which  the  eocond  containa  cither  a  divulent  carbon  atom  or  two 

lioldngB,  vbich  makes  it  very  improbable  that  it  is  the  correct 

jrroiitn  (17).     It  iihonld  moroovor  he  noticed  that  it  con  tains  « 

liydroxyl-gronp,  wbor(>iis  the  aldehydes  have  none  of  tho  properties 

cnliar  to  mibHtancoit  containing  thia  grnup.     They  do  not,  for 

Bxample,  yield  esters  or  ethers;  and  pliosphornn  ppntachloridc  doM 

laot  n^jdace  Dil  by  01,  Init  cuueve  the  exchange  of  tho  oxygen  atom 

For  Jum  oldorinc  atoma. 

Since  the  second  formuln  is  not  in  agreement  with  thd  proper- 
of  the  nliohydos,  it  follows  tliat  tbo  Srat  is  tho  <->orrect  one. 
This  view  U  HUpportod  by  tho  fact  that   tho  aldehydes  are 

"5 


ORGANIC  CHEMISTRY. 

formed  when  acid  cbloridee  dissolred  ia  moiat  ether  are  acted  on 
wiUi  godiiim,  tLe  chloriuo  atom  b^ing  replaced  by  a  hjdrogtfQ 
atom: 


.C,li, 


c< 


H 


lhitrnld«h)rd« 


The  ai<Uhyde4  are  th«re/ore  ccrnpounds  which  ctmiain  the  group 

107.  It  was  stated  iti   106  that  the  ketoaea  are  formed  bj,j 
the  oxidtttiou  of  lUo  soooud&ry  alcohols.     The  ketouea  likeviMJ 
lack  the  propertiee  puculiar  to  hydroxy! -compouudb,  which  prove*' 
that  the  hydrogen  atom  of  the  hydruxyl-group  has  b««u  removed 
by  the  oxidation.     Lcuviug  out  of  acoount  th«  iKMsibility  of  the 
selliuf;  free  of  bnudi*,  the  rvmoval  uf  the  eocoud  hydrogen  atom 
can  ouly  take  plaoe  iu  one  of  two  vaye — from  the  same  carbon 
■atom  to  which  the  oxygen  is  linked,  or  frnm  the  olner  oarbon 
patom.     ThiB  cut!  be  illutitrated  iu  thu  following;  way,  R  and  R' 
reprmeDting  tdkyl-groupa: 


I. 

U. 

CH.B 

CH,B 

CILR          CHR 

CHOii 

—  CJO            01 

1                \>^ 
CtlOU  —  CH 

OH,R 

CE,R' 

illjR-         CH,R' 

For  reaeoDs  analogone  to  those  rtatcd  in  the  caso  of  the  aldehydes, 
formula  I  U  more  probable  than  formula  IT.  The  prodiuns 
obEnined  by  tlie  oxidatiDn  of  the  ketones  .ihow  that  their  conslitti- 
tion  \e  in  fact  repmaented  by  formula  I. 

The  general  formula  for  a  secondary  alcohol  is 

R.CiL-C;^CH,R*; 
NOH 

from  soch  an  alcohol  two  acids,  R  •  U  H,  ■  COOl  I  and  U'  ■  OH,  •  COOH, 
are  obtained  by  strong  oxidation,  the  carbon  chain  Iwing  broken 
in  some  oF  the  molecnles  to  the  right,  and  in  others  to  tlie  left^  of 
the  CnOH-group.     A  means  of  determining  what  alkyl-groiipg 


ALDEHYDES  AND  KETONES. 


an  Knk«d  to  the  group  — 0 —  ia  any  aecoiidary  alcohol  is  afforded 

Oh 

brthis  renction.  .Since  ihe  imme  auida  ure  oMatned  by  oxidising 
k«(onea,  wliich  are  timmselvBH  produced  Ijy  Kubmitliug  secondary 
atcoholfi  to  gentle  oxidation,  ii  follow*  tlial  the  aJkyl-groups  of  the 
fivK-ondxry  alcoliols  muitt  exiHt  uimhaugui)  iu  thu  ketone.  Henco, 
sucli  a  Btrnctnre  as  that  rt-preBonted  by  foroitila  II  is  ciduded.  ao 
that  forniula  I  miirt  bo  the  correct  one 

Kttones  tkfmfore  contain  the  yrm»p  CO,  called  tho  earbonyl- 
group,  liNktd  to  two  airbnn  aiovm. 

AldfbydcB  may  he  looknd  upon  m  ketones  in  whioli  an  alkyl- 
group  hiu  be«u  replaced  by  hydrogen. 


d 


VomeQcUtarc. 

108.  Thp  nnme  aldehyde  is  derived  from  n/(cohoI)  dehy<l{ro- 
genatiis),  tluit  is,  ''alri)ii(d  frnni  which  hydrogen  line  bcseu  uli- 
etracte^l."  Tho  wonl  kptotic  has  it«  origin  in  Ibc  name  of  tbo 
first  membt'T  of  tiie  ecriM,  oettone,  CH^-CO-CH,. 

The  aldtihydoti  are  named  after  the  correspouding  iicids: 
formaiiIekjfd«  H-CHO.  tu-ftaUh-htjde  CHj-CFTO,  jn'opioHiihleh^ftt 
C^.-CHO,  vaUraMfhyde,  C.H,-CHO.  etc. 

The  kutonea  derive  their  names  from  the  alkyl-grnupH  whirh 
tbcT  coiitatii:  itiiurthj/Ucciune  CIl.-CO-UU,,  iMthi/ijirojfylkfliiM 
CH,-CO-C,II,,etc. 


M«thod»  of  Formation. 


100.  There  arc  lifveral  nietiio4l«,  other  than  the  caidBticm  of 
alcohols,  applicable  to  the  pre)mration  of  Wlh  aldehjrdM  and 
ketoue«. 

I.  Drv  disciUation  of  the  ealts  of  tho  fatty  acids,  caloiutD 
tiootate  violda  acetone: 


CU,.C0lIJ3i 
CH,.  COOca 


=  CH.-CO.CH,  +  CaCO,. 


•c«  =  iCa. 


1 28 


ORGMWC  CHEMISTRY. 


Axi  altJehvcIe  in  produnecl  by  the  distillstion  when  an  equivalent 
(jiiantitv  oi  a  formate  is  mixed  with  the  mlt  of  th«  other  fatty 
acid: 

COONa 


o,n,.co 

H 


=  O.H,-0^g  +  Na,CO,. 


Loiitly,  mixtd  ketonta  btu  ubtuinvd  when  a  mixture  of  the  salts  of 
two  difier«Dt  fatty  acids,  except  formats,  ie  diatillod: 


Id  tbft  laat  two  rtuctiooB  the  produut  cootaiua  tbv  correspoudiDg 
rimpte  ketones  in  nddillnn  to  ihe  iildeli3'(le  or  mlxtMl  V«loiiv.  TtiUK. 
in  tbe  exAinple  viivtn  abovv,  diiiivDivlliclotiv  uud  dictfa^llcvtone  ar« 
also  formed. 

Givea  lUe  slruoluro  of  tlio  f«lly  acida,  the  method  of  formutiou 
JuM  dewrlbed  could  be  put  forward  tM.  a  proof  of  llie  conslitiiiioii  of 
thoiddchydcB  and  ketones,  if  il  urem  itot  tliat  thu  reaction  only  takes 
place  lit  liigh  lunyjvntlures.  SiiicL*  ;iiidvr  sucli  oooditioris  orgaoJo 
flompouoda  frequently  undergo  chai)Ko»  of  ^truolure,  more  especially 
al  t)in  mflmcnt  of  formation,  nuoh  pjfrojrenetic  reactioiiA  caimoi  be 
ngardod  as  fumiabing  couclusirc  evidenoe  of  the  oon«tilution  of  a 
oom  pound. 

2.  Aldoliydea  or  ketones  (ran  W  oUtiiincitl  from  romjioiiiKlei 
containing  two  halogen  atoms  linked  to  h  ginglo  carhon  atom,  br 
heating  them  with  water: 


CH,.CH!C1.  +  HJ0  =  CH.CHO  +  aHCl. 


Kthrllrfoav  irblurMa 


i 


3.  An  important  method  for  the  preparation  of  Icetonoe,  but 
not  of  aldehydes,  is  the  interaction  of  neid  chloridefi  and  ainc- 
alkyl*,  or  nine  alkides  (82).  When  thn  two  aub«ti»rirc»  are  brought 
together,  an  addition-product  is  firat  formed:  this  ran  only  result 
throngb  the  changing  of  the  double  bond  of  the  oxygen  atom  into 
a  single  one: 


C„I!,.. . , .  C  <  ^,  +  Zn  <  ^H'  =  CH 


•CI 


GH, 


/OZuCH, 


iQ  is  (onnvd  when  this  adilition^product  U  treatetl  with 


■  >CI  Hi 


,lI^,,-CO.CU,  +  ZoO  +  CII. 

+  lUM. 


^ 


h 


llOi  ScTeral  properties  rommon  to  the  nldchvilce  and  ketones 
d*]icnd  on  their  power  of  forming  addil  ion-products.  This  pow*r 
1ia<  its  ori^n  in  tho  double  bond  of  th«  oxygen  atom,  the  conrer- 
Kon  of  wlii<>li  into  a  iiiijji;le  buiirl  svl^  free  n  cHrbon  and  iin  oxygen 
linking.  This  etiabU'«  tlie  aldebjdeK  and  ketoL^s  to  form  additton- 
pror)nrt8  with  the  following  elements  and  coinponnda. 

1.  Hffilrtt^ni. — An  ttdditioii-prixluct  is  formed  by  the  action  of 
«odiiim  amalgam  on  an  aqiitions  ^lution  of  thf  aldehrdea  or 
ketones;  or,  if  they  are  insoluble,  on  a  mixture  uf  them  with  water. 
PrimaTT  alcoholo  are  Conned  from  aldehydoB,  and  secx^udary  from 
ketones. 

2-  Sodium  hi/drofftii  sulpkHr. — Wlien  aldehyde*  or  ketones  are 
shaken  up  with  a  verj'  eoncentrated  solution  of  thin  eompooud,  a 
crystalline  udditiou-prodnct  \a  obtained : 

C,H..C'<°  +  .\aHSO,=  C.H.-(  <X  \a' 


U 

compounds  is  assigiiwl  the  constitution  indicated  by  the 
"fonniila,  because  they  are  very  ea.fily  converted  hy  the  aclioa 
of  dilute  acidn  or  Bodiiim  carbonate  mlntion  into  the  correopond- 
iug  aldehydes  or  ketonee ;  in  the  ciue  of  th»  higher  members,  mere 
aolntion  in  water  effects  this  decomposition.  For  this  roa^ton,  it  )i 
highly  iinprohablo  that  thero  is  n  direct  bond  between  sulphur  and 
carbon  (67).  The  acid  sulphite  compounds — Bometimes  incor- 
rectly callo<l  bisulpliile  pompouiuls — fiissoWe  readily  in  water,  but 
ore  insoluble  in  very  concentmUid  ootutioQA  uf  thu  ucid  eulphite 
iteelf. 

I  The  ketones  du  doI  all  give  these  wlOitioii-prwIiicir.     Tliey  ant 

moat  readily obtfli nod  iron  Ibosc  eonHLttiing  ntic  mctliyl-graiip  dinwtty 
linked  to  carbonyl,  or  melhylketones. 
Then»  of  acid  eiilphite  i«  often  exceedingly  aen-iceable  for  the 
nriScation  of  aldeliydcs  or  ketones,  or  for  Bcpomtiug  tbem  from 
react  ion-mixtn  res. 


IJft 


ORCMSK  CHEMISTRY. 


Z.  Uytlroeifanie  arid. — When  aa  aldohydo  or  ketone  la  hroagl 
into  crjtilu'-'t  wii}i  an  iiqutxiUB  wlution  of  hydroojuiic  acid,  cooi> 
Unutiaa  taktw  piucc: 

Tlili  la  H  very  itnportntit  iijiitlie«i8,  beranm  the  liydrox;<ni[rilea 
tliiiA  fnrmiiil  rjiii  Ik*  converted  into  hrdrnxT-wids  hy  mponification. 
Thi»  ttlTonlft  11  nieiiiis  <it  ByntliBBijtiDg  compounds  of  the  latttr  claaa  j 
(188,  6). 

111.  Willi  (iiticJK.vni>'Ef  alkyl  nmfpiesium  h&lidea  (82),  ftldo-, 
liyrli'H  ami  ki'toima  form  luIilitiuu-pruiiuc'tB,  wliich,  on  treattnest 
witli  walor,  vii'ld  ruiipt>ctlirtily  aoeoudHry  ur  tertiary  alcohola: 

H 


H 

S«COM(tI 


RO?.  +  H'MgI  =  RC^OMgl. 

AttMir<l«  AddlUan-proiluot 


SII.O  =  8RCH0H-  R'  +  Mgl,  +  Mg(OHL ; 


AMlUaa-pnMluol 


oh; 

AmMim 


aHS'>l!  <  cu  ^'*''  4-  m.O  =  a(CH.>.COH  +  M«Br.  +  Mg<OHV 


TVimcUij  Icftrliluol 


118.  Otlu>r  proprrtii'tf  commou  tu  ti)iIi-hTdt»  and  k«toQc 
ujwtt  thi>  fact  tiMt  thf  doubly- litikod  oxygtn  atom  can  be  ex< 
for  otliur  «t»viiw  or  groiijia. 

1.  FktigftJknrtit  jmtlarMhritii  n>plRt.<««  tho  oxrgeo  atom  ^  tvo 
vhl(iriii(>  atoms. 

j.   Hjfiimijilamin*  Rttcta   ia   aroonLuico   irith   the 
vqnation: 

Thr  conpowHls  Uius  fortiMd  baw  tbe  ^oenl  mm?  ani 
calM    mUtMtmn  vb«K    tber   ar»  4enT«d   fimn    aHatTita, 
Jt»tmnmn  vben  deriTcd  (ran  kefODes.     Tlut 
gmrnA  appUcalioo.    The  otiiDia  are  citKar  i 


lA 


MLDEHYDES  AND  KETONES. 


U» 


» 


orliqn)ds,and  posKosB  both  acid  andbiutic  properties.  When  trentcd 
vith  bases,  tho  hydrogen  of  tho  hj'droxyl-group  in  replaced  by  u 
metal;  mth  ncids,  addition-prodQcte  arc  formod,  the  reaction 
boiog  similur  to  the  production  of  iimmonium  suits: 

Acolollme  tijilmcbitirlilo 

Ou  boiling  with  dihite  hydmrhluric  acid,  the  oximcs  tnko  ap 
ene  molecule  uf  wuter,  yielding  hydruxylumLtte,  and  tiithor  an 
tliloliyde  or  a  kutoue. 

The  following  is  a  proof  of  tlie  oonsLitation  girca  above  for  the 
OBimes.  Tbero  can  b?  no  doubl  ihat  when  hydrosyl amine  acta  on  a 
lioioiift  or  an  aldehyde,  coiidaiisatioii  lakes  placo  wilh  diraiiialioii  uf 
till'  vaU>r  funned  by  ihe  union  of  tlio  hy(iroj;[i'n  of  tlir*  hydrozylaitiino 
with  ihc  oxygen  of  \hv  carbitnyl-gniiip,  bL-oniinc,  if  tho  alkyl-groups 
tonlk  pnrt  In  tlia  rtwctlon.  ibc  rcgunonitioti  of  ttio  aldAliydo or  ketone 
would  iiot  bo  so  readily  effected.  Tbc  po&siblo  Btniotural  formulra 
for  the  oximea  ar«  tborefura  reduced  lo  tvo : 

I.  n. 


HO, 


>C|0 


> 


>C=NOa  and   >C 


II 


II 


> 


•<Jb 


The  oximoa  contain  oub  hydrogpti  atom  rephccablo  by  an  alkyl- 
gnap.  When  audi  itn  alkyl-oxime  is  boiI«d  wiili  faydroohlorio  acid, 
there  \t,  formnd,  in  addilion  lo  the  aldehyde  or  ketone,  an  nikyl- 
hydroxylatnlne.  This  hn«  thi^  eoniititulion  HiN-O-R',  boeati&c  nn 
beatinj;  it  with  hydriodia  auid,  tlm  nlkyl-^roup  ih  nplit  oR  with  furmii- 
tioD  of  all  alkyl  iodidt-,  a  rBautioii  which  could  not  ttiku  placo  if  the 
alkyl-gmup  were  directly  linked  to  tho  niiroK^n  atom  ;  sinoe,  if  lliis 
were  the  onso,  nn  alkyl-nminc  woulJ  of  nectiwdty  bti  formed.  For. 
mula  n  ia  Lhoi^fora  excluded,  aa  rcplucomont  of  tbo  liyilrugen  alum 
in  its  NOH-gruup  indicates  the  formation  of  a  oompound  containing 
an  alkyl-groap  dtrccllr  linked  to  a  nitn:^n  atom. 

Energetic  reduction  converte  tho  oximes  into  amities; 
R,.C^K01I  +  4H  =  R,CNn,  +  H,0. 

H 

The  aldoxlmes  are  readily  tranaforniBd  into  tho  corresponding 
nitrilus  by  tho  action  of  dL-hydrutiug-ageuls,  snch  as  acetio 
anhydride: 

aU^ . , ■  0=NiOU  —  C.n.„ , . ■  CzN. 


AlDliHYOES. 


*53 


I 


&LDEIITDE8. 

lis.  Id  addition  to  tboKc  mvutionod  ubove  (110  to  112],  which 
the;  share  vith  kotonce,  aldehydes  posaoes  th«  foUov^g  properties 
peculiar  to  thcTuselrcR. 

1.  Tliey  form  iiddition-prodiicts  with  ammonia.  Thas,  a(>«t- 
aldehTdc-ttmmoniik  is  prodncecl  when  aRimouin  reavt«  with  weXr- 
aldohyda: 

C,H  0  +  NH,  =  CjH^ONH,. 

AoetmlJehrde  Ac«tAlilab)'dB«miiicnUk 

It  is  pracipitated  in  the  form  of  white  crystnk  wiieii  diy  aromnnia- 
ga«  is  pssm^]  into  a  Holiition  of  acetaldehjde  in  carefully  dried 
«t her.  ami  is  rerv  soluble  in  water.  Acids  deconipoab  tht- uldu- 
■  hyd«-aminonia  compounds  intothvir  romponent-s;  caustic  potiiab 
u  noable  to  effect  this  dMomposition. 

H  Tho  molecular    formiilii    of  ac^taldehjrda-ammonla    at   ordk 

^^^^  tenpentttirea   is  thr««  timea  tliftt  of  its  ciu|iirical   foruiulu. 
^^^^dried  over  nulphurio  acid.  It  loses  wat«r  easily,  being  oonrerMd  inlo 
^^^B(OHt'CIINIl)i,  which  in  a  polymer  of  ethyUd«no>tmine. 

■tiun  w 


2.  Reaction  with  ulcuhoU.    Aldehydes  are  oapahlc  of  oombinn- 
Etiun  with  two  nioleculee  of  alcohnU,  with  idiminHtton  of  water: 


cH.-cv,'  +  ;;i-;;;;-cn..c<^^^;;;+ii,o. 


,0 


nioo.n. 

HOC. 


Theae  compounds  nr^  rolled  arttah.     They  are  readily  formed  ly 

the  addition  of  thv  aldeliydtt  l\>  a  \ii  doltiliou  of  anhydrous  FICI  ui 

ttk-ohol.    This  reaction  ie  not  complottf;  it  is  limited  by  the  reverse 

one.  nnof  water,  acting  on  ut-etal,  causes  the  formution  of  aldehyde 

d   alcohol,     liolh    foriimtioit   and  deeompOBitiou   of  at;etal    are 

Dsiderably  accelerated  by  the  presence  of  a  small  quantity  of  a 

itrong  minernl  acid,  which  uct«  hero  a&  n  powerful  catalytic  agent. 

The  aoetalH  arc  lifjuidii  of  aruiiiittic  odour,   aud   distd  without 

eeompoeitJoo.     They  are  not  atlwhed  by  atkalie,  but  are  tiplit  up 

ly  wcids  into   the  coinponnda  frarii  which  they  were  produced. 

'his  latter  projwrty  further  cKlabliehes  the  structure  gi»eii  above, 

cording  (o  which  the  ulkri-groups  arc  linked  to  the  aldehyde- 


^^m 


>34 


ORGANIC  CHEMtSTRY. 


residue  by  tneann  of  oiygeti,  ninoo  a  carbon  l)ond  could  not  nanally 
be  broken  in  this  manner. 

3.  Additton-producta  are  obtained  with  avid  anhvdrides; 

cH..c'^  +  0{C0CH,),  =  cn,.cH<g^:2^U|. 

AoMk  wthj'drtj* 

Theftp  roRiponnds,  whicti  are  atialogons  to  the  iicctaK  am  AMiilj 
decomposed  by  vater,  and  still  more  eoail;  by  alkalis,  into  tlie 
oonvepondtng  acid  and  aldehyde, 

114.  The  al(iehyd*8  further  pos»e«e  th©  power  of  pombininf.' 
with  thomsplvos.  This  X9k««  place  iu  two  ways.  When  a  few 
drops  of  concentrated  mlpharic  acid  are  added  to  acetaldebyde,  a 
liqnid  boiling  at  22°,  it  is  ohnerved  that  the  mixture  betomps 
vurmi  and  eren  begins  to  lioil  violently.  At  the  end  of  the  re- 
action a  colourlesa  liquid  is  obtained,  similar  to  the  original  one. 
but  boiling  about  100°  higher,  at  134'.  The  empirical  fvnniila 
of  llii)S  compound  is  tli«  same  9*  that  of  aldehyde  itself,  C,H^O, 
bat  ita  Taponr  density  ia  three  tim«w  as  great,  tv>  that  ii  has  the 
molecular  formula  C,H„0,.  This  rompound,  ^Htraldeh^ile,  is 
readily  oonrerted  into  onlinar)*  aldohyde  by  distillation  with  dilute? 
eulphnric  acid.  Thig  is  another  example  of  a  reaction  limited  by 
th*  rcTorw  ono: 


C,H„0,. 


3C,H.O. 


The  e<jni1ibriiun  reached  must  be  iitdependent  of  the  nature  of  tha 
acid,  that  ts.  of  the  cstalytie  agent  ("Inorgaoio  Cheourtty."  49). 
This  has  been  proved  by  experiment  in  this  caae.  The  aame  state  of 
eqaitibriam  most  be  rc«ched  without  the  aid  of  any  catalytic  agent, 
bat  the  ractiou  then  proceeds  so  slowly  that  it  has  not  yet  been 
possible  to  prove  thia  experinieutally.  .V  diret^t  linkage  between 
the  carbon  atonu  of  the  thive  aldehyde  molecules  which  hare 
united  to  form  pantldehjde  is  improbable,  bat  a  linkage  throngh  the 
oxygen  atoms  mart  be  aosumed^  becaiiiJe  a  accounU  for  the  eue 
wrtb  which  tbc  molecule  of  panUdehyde  am  be  split  npL  It  is 
cot  attacked  by  sodium,  and  therefore  cannot  contain  brdroxyl- 
^rwpf.    All  the  characteriftios  peenliar  to  aldehydes  ue  wasting, 

dwviDg  that  paraldehyde  does  not  contain  the  group  — C^n* 


ALDEHYDES. 


'3S 


The  following  coustitutiotiul  fonuak  best  expneses  theu  proper- 
ties: 


CH,. 


n/^\H 


^(/ 


COH, 
A 


H 


The  linbing  together  of  two  or  more  rnolet^iileH  of  n  Hiibstance, 
with  formation  of  a  body  frooi  wliicb  tlio  origiiiftl  coiii]toun<l  uiny 
be  regenerated,  is  calleil  jiolifinn-izatioii. 

115.  The  union  of  tlie  alileEiyde  molecules  among  themeeWea 
takCD  pluco  in  a  dilTcrciit  way  when  n  ililiite  solution  of  an  alkali 
is  ncMod  to  nn  ikldehydo.  When  an  aqueons  solution  of  aoetiilde- 
hyilo  is  wanned  with  caustic  potash,  tho  lifjuid  boconies  yellow; 
after  a  short  time,  reddiKh -yellow,  ftraorphoug  mastses  are  pre- 
cipitated. The  aldehyde  liiw  re*inifitd,  and  the  reddish -yellow 
snhetance  formed  iB  (tailed  aldshydf-rcsin^  When,  however,  di- 
Inco  caascic  potaah  (or  sodium  acetata,  xino  chlori>(!c.  etc.)  is 
addc<l  to  acotaldohydo,  a  eitbetimi^o  ia  formed  having  the  ^ittne 
empiricnl  composition  s^  aeetaldehjdo,  hut  with  double  tho 
molecular  formula,  C,rT,0,.  This  compound  is  called  atdol;  it  is 
a  liquid,  distilling  without  decomposition  under  diminished 
prcfsiire,  &nd  reiudity  undorgoing  polymerization.  It  possesses  the 
prop«rtk«  peculiar  to  tho  aUIchydci,  yielding  on  oxidation,  for 
pxnmple,  an  aeid  with  the  fame  numbor  of  carbon  atoms.  The 
icid  so  obtained  has  the  formula  C,]I^O,,  and  on  investigation 
prorea  to  be  an  n-hydrnxybutyric  acid,  that  \s,  ii-hutyrin  acid  m 
which  one  of  tliu  Il-tttoms  of  the  ulkyUgroup  has  been  rfpltttinl  by 
hydrosyl.  It  cuu  be  converted  iutu  butyric  uctd,  wiiich  tuntutna 
ft  chain  of  fonr  carbon  atoms,  proving  the  prcscneo  of  such  n.  chain 
in  nldol.  In  thig  ea»e,  tlio  linking  together  of  the  uliielivdo 
moteciitcK  has  been  etfected  through  the  carbon  hondx,  a  further 
proof  of  which  is  that  aldol  cnnnot  bo  reconverted  into  aldehyde. 
The  following  equation  reprofents  tlie  linkiug  together  of  tlio 
aldehyde  moleuulua  to  form  aldol,  the  formula  given  for  which 
accounts  for  its  properties: 


,H 


E 


,/ 


n 


CH.-Cl^+nOH,-C^  =CH,.C^CH,.C, 


'0 


'^ 


136  ORGANIC  CHEMISTRY . 

In  iiddiliou  to  the  nbuvi-  oii>liiiiitlioti  of  llic  formation  of  al<lol  bf 
tlw  <?otjil>iii»tioii  of  one  of  llie  byilrogen  atoms  of  one  aldelijrde  mole- 
cule with  thi!  uxyKirii  ;iiom  of  uiotlier  (o  form  Iifdroi^l,  it  might  lie 
cxplAind  by  n^umiiiK  that  an  aldehyde  molecule  unitvd  with  a  mole- 
cule of  WBli-r,  formiog  an  nddii ion-prod tict  which  rcAoUirltli  b  Moutid 
iQoleoulo  of  aldebydo  with  eiiutuntlo'D  of  wntcr  1 

ti 
CH.-oJ  +  H.O=  CII.C<gg: 

™  ^<on H 

•         |OH  +  HlOHfCHO  =  CH,  C<iJH\.<;nn+  H'O- 

AMo) 

The  formstioD  of  such  aa  addition-prodnct  with  aubscquent  «ltuiiuA- 
tion  of  the  urxler,  is  frequi'iilly  Assumed  to  taifv  pUou,  \\i\i  assuiop- 
tion  oftea  aiFarding  an  ox  plan  at  ion  of  the  course  of  rvnctiooe.  This 
has  been  experiDieo tally  veriflod  in  a  few  caaes. 

Aldol  U  both  ail  utt^oliol  and  uti  uMeliyile,  lience  its  name, 
a/i/(eb}'deiilc«]i)of.  Tlic  linking  together  of  molecules  through 
oarboD  honcts,  as  in  the  foroiation  of  aldol,  with  the  prodnction  of 
oompoundB  from  which  the  origitia]  enbstauee  cannot  b*  rcgOQ- 
erat«d  by  any  8im]de  method,  la  called  comtenfafiitn. 

It  is  probxote  tliat  aldchydv-rmin  is  h  product  rMulting  from  coii> 
tiouod  cofldciLsatioQ  of  the  aldol  molecules  with  elimination  of  'H-atcr. 
jual  as  aldol  it8«!f  «a&lly  loses  one  molecule  of  water  when  heated, 
with  formation  of  crotonaldehyde : 

OH,  OHOHCH.C)! - 11,0  =  CH.-CH:CH-C^. 

Ora(onnl(l«hjd« 


Test*  for  Aldehydei. 

116.  The  following  toatsaro  used  for  tho  detection  of  aldehydeti. 

1.  liesiiiiflcatlon  with  alkalis. 

3.  Reduction  of  uii  amnioniacal  silver  solution.  This  solution 
is  prepared  by  adding  exceiw  of  caiiMir  potaeb  to  h  eotntion  of 
ailver  nitrate,  and  tbeit  animoiiia  carefully  niilil  the  silTcr  oxide 
procipitatcd  \t  just  disdolrod.  When  this  liquid  is  brought  into  a 
ditnte  aqueous  solntiou  of  an  aldehyde,  and  the  mixture  warmiod. 


ullie  Mtror  is  deposited  ou  the  sidea  of  the  tube  in  the  form  ot 
mlitul  tuulallic;  mirror. 

3.  When  aldehyde  id  added  to  »  HQlutioii  of  magenta  which  liu 
l>ei-n  dcH^uIouriisi'd  with  tsutphurouH  ucid,  the  red  colour  is  rcAtotcd 
bj  thu  firrtnaticiii  of  couduUKutiuu-producte. 


Poniwldehyde,  ]T.C^§. 

117.  It  wiis  mentioned  iu  8S  that  formic  acid,  the  first  mom- 
bcT  of  the  homologous  McricB  of  fatty  ucida.  ha«  ocrlain  proi>crtica 
uot  poaaeeeed  by  the  lii^her  mcmhers.  FornnUrleliydv  ufforda  & 
striking  exAmple  of  this  phenomenon  of  disparity  between  the  first 

^    and  aiioceeding  members  iu  a  homologous  Beriea. 

H  FormaJdehyde  is  ubiaiued  by  the  oxidatiou  of  methyl  alcohol. 
This  ia  effeL-ted  by  puAgJiig  a  raixturu  of  air  and  mptby!  alcohol 
vapour  over  u  hot  spiral  of  platiDum  or  uopiK;r.  The  heat  pro- 
duced by  ihia  reaction  id  siiflk-ifiil  to  raiao  the  temperature  of  the 
^iral  to  i«dn««a,  aud  to  maintaiu  it  at  this  point,  provided  tho 

■  Btream  of  gas  is  passed  over  it  with  snfHcient  voloeitv.  Tho 
fonoN^dehyde  produced  h  absurtied  in  water  in  which  it  is  readily 
aohible. 

PFomialdohyde  in  g»6cou8  at  onlinaiy  tempemtitrea.  It  hag  a 
very  pungeut  odour.  Wlieu  cooled  with  aolid  carbon  dioxide  iind 
«(her.  it  liquefies,  its  boiling' point  biriuji  —  20°.  iiven  at  thia 
tempcratiiro  jinlymen7.ation  begiuB,  and  at  higher  tcmperfitiire*  it 
poljmeriies  wilti  explosive  energy.  When  the  ai^ueoiiH  eohition 
ie  eva{>unit«d  over  concentrated  aiilphuric  acid,  only  p«rt  of  the 
formii Idehyde  la  evolved  as  gad ;  the  rcat  polymurtzes,  mid  renviins 
behind  iu  thu  form  of  a  white,  urystulliue  uuu6,  colled  oxif- 
mrthtfierit.  The  molecniar  weight  of  tliia  polymer  U  not  known, 
bnt  on  heating,  il  is  rveoMveKud  into  forinnldcliydL',  wliieb  proves 
it  io  be  ft  true  polymer.  Formaldehyde  does  not  yield  an  aide 
hyde^umniuiila  on  treatment  will)  ammonia,  but  a  complicalod 
t'ompouud,  C',II,,N,,  htjcamefhyhneamiite,  a  cryatalline.  basic  sub- 
stonoa  Formaldeiiydo  doea  not  resinify  when  treated  with  csuatio 
potaah.  but  is  co&veried  into  methyl  oleohol  and  formio  acid : 


acH.o  +  H.o  =  on.on  +  ncooir. 


IJ« 


ORCMffIC  CHEMISTRY. 


The  otimt  of  formaldehyde  a!*o  r»idily  undergoes  polrmerixa' 
tiuu.  It  U  tlius  even  that  formalilehrde  and  its  derirMtiveH  dUpUy 
ft  much  gre«t«r  tendency  towards  potymertxatioa  thiin  do  tltt- other 
•IdehTdes,  and  differ  from  them  in  their  bebaTtOQr  vitb  ammonia 
and  vrilh  L-suetic  poUsh. 

An  aqueous  solatioo  containing  iOit  of  formalduhj-de  is  add 

tin(l»r  the  name  "formalin."     When  di]ut«d,  this  \t  aaed  oa  n 

dirinfectant,  and  in  the  preeerratioa   of  aiiatomicul  a[>ecimen8. 

It  poneasee  the  remarkable   property  of  coDTerting  albaminous 

fnbetances  into  a  hard,  elutic  itioss,  qttite  insoluble  in  vater. 

iThe  conteutA  of  a  hen's  egg,  lor  oxample,  nudt-rgu  this  tranti- 

rfomuiEion  when  left  in  contact  with  fontialiii  for  hulf-an*honr: 

brain-anbstance  nttaing  the  00D8i>t«iiicy  of  india-rubber,  and  a 

lacion  of  gelatine  is  conrertnd  into  a  hard,  traoHparent,  insoluble. 

lonrlesi  maas,  redacible  to  a  fine  powder,  "ib  drops  being  used 

f(>r  every  500  g.  of  diesolvod  gelatine. 

The  coDc^nlnttion  of  A  formnlln  «oliitii>ti  is  il«lemiin«d  by  ikddjnf; 
excMo  of  a  solution  of  sudiuDi  liydrozldc  of  twice  ibe  normal  strength, 
follotred  by  hydrojcen  peroitide,  wbiob  eonverla  the  formatdehyde  <«>tn- 
\ibAK\j  inro  fonnlc  acid.  Tlin  araotint  of  alkali  not  lalceit  jiji  hy  thU 
acid  i*  Miitnated  by  lilnitioa,  from  tlic  reaull  of  which  ttie  amount  of 
formaldehyde  can  be  culvulated.  since  one  moleoule  of  lli«  aldehyde 
fields  one  molecule  of  the  acid. 


H 


Acetaldehyde,  CH,.G<y 


118.  AcetaMehyde  may  be  regarded  as  the  typical  aldehyde  of 
lis  eeriea.  It  ]io8»ee«ea  the  propertioe  given  above  aa  genemt  for 
this  ela(»  of  compounds.  It  \%  obtained  by  the  oxidation  of  ctliyl 
Joohol  by  means  of  potjusium  hirliromate  and  Kulpbnric  arid,  and 
a  liquid  with  n  diaagrneahle  odour,  at  least  in  a  dilute  state: 
''it  boiU  at  2:;'',  and  fiolidufieAat  —11^0  (P.  Aa  already  stated  (114). 
it  easily  nndergoos  polymerisation  with  formation  of  psiraldehyde, 
C,H„Oj.  Anoilipr  eonipound  having  the  formula  C,H„(>,  also 
existe,  called  mviuldehyde;  it  is  a  crystalline  product,  and  must 
be  likewise  a  polj-mer,  since  heating  reconvert*  it  into  ordinary 
aldehyde.  As  in  the  caw  of  paraldohydo,  it  dofis  not  give  the 
^ordinary  aldehyde  rtTttCtions;  for  example,  it  is  not  resinified  by 
lis.      Paraldehyde  and  ni(>taldehyde  are  pogsiblrstorooisnmers. 


KETONES. 


'39 


EETOITSS. 

projierlles  of  the  Itetouea  have  been  already 
moationed  (110  to  112).  The  flrat  tii«ui)>er  of  thtt<  homolojrouo 
MrJM  oannot  roiilnin  him  thnii  thn^>  rnrWn  atnms. 

Ejqwrieiice  lias  flhown  that  ketones,  whkh  may  b*"  repreaenteil 
<by  the  genera,]  fcirmnla  R-CO-B\  are  nlu-ikVR  split  up  ut  the 
carbonvl-groii ))  on  oxidntion  (107):  Ihat  is,  uxidittion  oiTiint  ut 
tlut  poiut  in  liiuiiiolociilv  at  which  oxygitn  isnlronily  presc^iit  (49). 
Tliis  deoonipontion  can,  howerer,  take  place  in  two  difTerent 
■ways: 


R.|CO.R*    or    R-CO|R'. 


Heihylnonylkfltone,  OH,'|CO-|C^H,, ,   for  exiunple*  cbq  yield 


^■fonnic  acid.  Oil, 0,,  and  caprit:   acid,    C\,H„0, ;  or  acetic  acid. 

0,H,0, ,  and  pflargonic  acid.  C,H„0,;  ftooording  us  the  decompoai- 

tion    take  splace  at  the  points  indic^to'l  by  tho  liiiefl  I  and    11 

^—^respectively.     The  oxidation  is  actually  Hunh  that  the  decompoai- 

^Btion  takeR  plai-e  at  both  points  8imultun(<ou>t1y,  so  that  four  acids 

■^^  ar*  obtained.     Two  of  thcittT  may  be  identical;  for  example,  the 

oxidation  of  raothyletliy  I  ketone.  (-m,-CO«C,Hj.  pruducea  ucolic 

and  acetic  acid  by  dvcompudiliun  at  on«  point  of  the  niolvculo. 

vhile  if  it  takc8  place  ut  thv  other  point,  formic  nud  propionic 

ocidd  ttPo  proiiucod.     In  the  majority  of  eaa-s,  one  of  thew  reac*- 

tiong  prodoniinulCT,  nwiatly  that  one  which  leaves  tho  cnrbonyl 

linked  to  tho  BninlleRt  iilkyl-renidnn.     The  oxidation  nf  the  ki^tones 

therefore  affords  a  means  of  detorminiiig  tlio  poaitiun  wJiii'h   the 

csrbony] -group  occupiea  in  the  molecule. 

The  ketones  are  further  dtstinj^iiahcd  from  the  aldubydos  by 
their  behaviour  towunli*  limmoiiia;  thi^i  ha*  been  niirefiilly  invASti- 
gated  in  the  ciuie  of  anotonc,  the  finit  momhor  of  the  series. 
By  elimination  of  water  it  yiehU  complicated  suhiitances,  aueh 
M  tUartioiitnmiuf,  (',II,.N(>  (3(^.11.0  +  MI,  -  H.OJ.  trinretmu- 
amin4,  C.n„NO  (SC.U.O  +  NH,  -  2H.0),  etc. 

The  ketones  do  not  yield  polymerB,  but  are  capable  of  lorming 
condeniiatioti  -p  rod  ii  c  tn. 


I4» 


OHC^WC  CHEMISTRY. 


Acetone,  Cn,CO-CH,. 

120.  Acoton©  38  prepiirod  un  tho  manufactnring  scale  from 
crude  WDOid-spirit  (46),  >md  by  tho  dry  distillutioti  of  pulcinm 
■cetate.  It  b  prei>ent  in  rery  small  ({iiftiuitiex  in  iioriiiHl  urine,  but 
in  mndi  greater  amount  as  a  rewilt  of  ]>athnlngipal  condilionfl, 
>H  in  ouea  of  diabelu  mflliiv*  und  actionKria.  It  in  a  Hqtiid  of 
peoiUiur,  poppemaint-likc  odour,  boils  at  ^t»-3'%  eolidiflM  nt 
—  94-g*>,  luid  hae  a  spocifio  gravity  of  0-813  at  0°.  It  is  hd  excel- 
lent Rolront  for  mnny  orgiitiir  rotngiouncls,  and  is  miaciblo  in  all 
proiHirtioiiB  witli  water.  It  is  rnnv«rted  by  reduction  into  iso-| 
propyl  iilpohol,  and  yieldfl  a  crycitalliDR  oxime  molting  at  C!>°. 

SttiphotMl,  A  coitipnuiid  iminnaiil  in  medicine  «a  a  ttoporiflo.  ts; 
prepared  rniiti  neclone.     In  jiraAGnce  of  hjdrocliloriti  ftcid,  acetous 
anil«s  ffitb  olbylmcrcaptnii  wIlli  eliiniiintiou  of  water: 

(oa,).co  +  aiisCiU.  =;  (CH,),0(So,ii.),  +  h,o 

DliiiHtti  UilHilivl- 
Oxidation  witli  potassium  pemnnngnnnlo  converts  ihc  two  stdphnr  alomft 
or  ttiU  compound  i[ito  SO^grnups.  forming  dicltiylsulphuncdiiaclhyl- 
nifithane,  (C[I,j,C(SO,C,l]ili,  or  sulpliumtl.  It  ciystailiz^e  in  colourlesa 
prbiiiH,  which  diatMlvK  nicb  dilBcutt}'  in  cold  water,  and  molt  at  IJW*. 

ThioiMahfdM  &ad  Thiolcetonea. 

HI.  Thuna  are  onniponnds  eontaining  aiilphur  in  place  of  Ibe  osy- 
Ecii  of  till!  aldcliydcs  and  Itt-imics.  'niioaoci aldehyde  Li  not  itself 
ktif^wo,  but  itii  pctlymcr,  trithianNialdtfiyilt,  CiHttSi,  is  obtained  bjr 
lending  suIphiirLltcd  bydrogou  inlu  aoi-Ialdcliirile  in  prrscuco  of  hydro- 
shloriti  acid.  Otidatiori  convene  it  itilo  n  trijulphond  (97),  eauli  sul- 
phur atom  being  oiidizcd  lo  an  SOi-group, 

Although  nceioiie  iraoif  docs  nut  iindurgu  poljruiorizatioD,  replaoe-j 
mviit  of  il!t  oxy):rn  ai.oui  by  a  sulphur  atom  confera  ibiH  properly  on  It] 
111  ft  liigli  di*gro(>.    Tilts  poly  men  an-i  ion  can  lie  effootnd  by  tiie  meltioda 
applied  tu  aldcliydttt.    Tliroo  molooulea  l>e«oiue  linked  logetber,  fom* 
in^  trUkioooatt>H9,  i2,\l,A%. 


TIHSATTHLATXD   HTTDROCARBONS. 


L    ALITLEKES  OB  OLEFtVBS,    C„Hni. 

Hfltboda  of  Formation. 

123.  1.  The  oirjine.i  un;  olitaini'il  in  the  dry  diiiitlUtion  of 
complicaktcl  car)>oii  couipoiinde,  which  uccounts  fur  llieir  prcHvnce 
to  the  cit€nt  of  i-i>^  in  c<ial-g*s. 

'i,   Ity  elimination  nf  the  elemenhi  of  water  from  the  oloobo]* 

c,n„.on  =  c,u„  +  H,o. 

Thia  can  sometimes  he.  brought  atout  )iy  mere  he&ting,  as  in'tha 
caw  of  tertiary  uk-oliuk,  but  U  is  iietially  iiHrw»iary  to  heat  tha 
klcohol  with  a  dcliydratiiig-afreDt.  such  am  conccntTated  Bulpliiiria 
ncid  or  zinc  chloride.  The  oliminatinn  of  water  from  the  secondary 
uA  tertiary  alcohols  in  more  easily  cffootod  than  from  the  cor- 
responding primary'  cuiiipoundB. 

3.  By  splitting  ofT  a  haloid  acid  from  alkyl  halidiw.  This 
itearriod  out  by  heating  the  latter  with  alcoholic  potash,  a  solatioa 
of  caiutic  pota«h  in  alroliol: 

C„M,„ .  ,1  +  KOC,U,  =  C„n,»  +  KI  +  CAOH. 

Sther  ia  formed  at  the  »ame  timo  (98): 


c,H^ .  ,1  +  Kocyi,  =  c..u„  .,oc,n,  +  ki. 

ftlkyi  iodides  are  used,  the  reaction  taitos  ploco  rhiefly  In 
"aMOfdanc*  with  the   first  of  tfiew-  two  oqnutJont),  tho  socondary 
ind  tertiary  indidcs  lieiiig  spocially  gnltod  for  the  pruduL-tion  of 
nngaturntcd  hydroc&rboiu. 

»4I 


ORGANIC  CHEMISTRY. 


Xani*. 

Pofmula. 

IlolUtiit- 
(raint. 

Hune. 

Foraiula. 

BalHnr 

p«4lK. 

EUivtnnn. 

l*r<>pjlrnc  .... 
ii-BuiyloDe,.. . 
n-AtiirtMi«.., . 
Hncjffttau 

C,H, 

C.n. 

0M.:C1I-CB, 

C'«H„ 
C,II., 

—  6* 
68* 

nvpiyleus. . . . 

No«)  vIras  , , , . 

c.u„ 

c,.u„ 
c,.u» 

se* 

153' 
173* 

Tlie  naiiie«  of  tho  metnlierR  of  thiK  svn^  hfr  ilerired  from  ttioiie 
of  the  saturated  hydrocarbons  hj- alltring  the  tcrtnination  "mif" 
to  ''yleiie."  'I'heKiR  conipouude  art*  duuotvd  l>y  tbo  g«Qcral  diuiic 
atki/lftus  or  <ftt^tui. 

In  order  to  indicato  the  position  of  the  double  linking  in  tJio 
molecnle,  the  nlkylenoH  arci  BomtitimHii  rngurded  u  aubtititntcd 
ethylenes;    tlins,    CIl.-t'H  :  OII-CII,   h  culkd   nyinnifiricat  di- 


tMthykih^Unt, 
alkylms. 


and      (CUJ,C  :  C'H,,     oKgmnuirical     dirsuihtfU 


Prop«rtiM. 

I'SS-  I'hc  lowAst  mcmbera  of  this  homoiogonfi  Sdrics  arc  gasee, 
and  are  slightly  Kolnblo  in  wat«r;  the  higher  DiRmhera  are  Utjuids 
or  solid*,  iiisohible  in  water,  but  sohiblt  in  altxiliol  and  ether.  At 
their  mcltiug-poiut^  the  specific  gravilk-a  of  the  luwor  membera 
arc  about  0-S3,  rmng  witli  increase  iu  the  numlwr  of  carboo 
atoms  to  about  0  ^it. 

Their  roost  importiLnt  eliemical  property  is  tho  powor  of  form- 
ing additiou-products,  on  account  of  which  they  are  said  to  bo 
vmaturnted.  Add i lion-prod uctn  are  very  readily  obtained  by  the 
action  of  the  hiilogciiB,  eepvcinlly  bromine,  on  the  olclines.  and  in 
general  on  substances  contaiuioj:  a  double  bond,  the  presenoo  of 
which  can  be  detected  by  their  power  of  docolourining  bromine- 
water.  Another  tei>t  for  thn  pri^Renoe  of  a  double  linking,  eug- 
goeted  by  Bartcu,  in  carried  out  by  shaking  tho  gubetaneo  with 
a  dilnl«  Kolution  of  potafutiiim  permanganate  and  Rodinm  e«rl>onatei. 
Owing  to  rcduc-Lion  in  prL^senre  of  ii  double  ciirbon  bond,  the  violet 
colour  of  tbo  permanganate  (jnickly  disappcarB,  with  formation  of  a 
brown-red ,  floccnknt  proci]>it8te  of  n  hydmCo  of  inanganei^ dioxide. 
Various  claasea  of  eomponnd>>^  for  example  aldohydes,  react 
similarly  with  pataKsium  permanganiito,  6o  that  tho  teat  can  only 


OLEFINSS. 


'43 


be  applied,  «li«n  tliey  are  abaeot,  to  hydrociirltouit,  uu8at4intt«d 
acids,  and  i\  few  utia-r  oubfitaiiceti. 

The  haloid  ncids  r«act  by  addition  with*  the  olelinee  to  fonn  the 
(ilkyl  h»licle8-     Ilydriodic  acid  combines  in  this  way  vorj*  rondjly. 

f'oncomTnt<><i  siilpliuric  acid  yioldfi  tho  n]k_vl-fi!i!|ihnric  acids  by 
wJditioii,  it  being  Koiiietimea  necosrary  to  rmploy  the  fuming  acid. 
The  addition  of  sulphuric  acid,  like  that  of  the  haloid  aci(l«, 
n-fulte  in  tlie  union  of  the  ocid-residue  with  the  unsntumled 
i:ari>oo   atom  linked  to  tho  smalleBt  amount  of  hydrogen.     For 

example,    isobutylcuv,  S.,*>C:C1I,,  tioatcd  with  ealpburic  or 

hydriodic  acid  yields 


CH 


'>C— CH,         or 
OSO.U 


I 


This  reaction  may  bp  oxpreiuied  in  another  way  by  Ktating  that 
there  is  a  tcnd«ncy  on  the  piirt  vt  ttip  mpthyl-groupa  to  iucroaso 
in  camber  in  addition-reiictions  of  this  kind. 

Ilypocblorous  acid,  ClOII,  citn  also  form  additiou<producti> 
which  are  chlorinatod  alcoholii: 

CH,  =  cii,  +  cioii  =  cn,ci-cn,on. 

Stbylene  GljraoietaiorbjrdrUi 

124.  OlefineH  can  also  form  condensatioii-prodiicta;  fur  ex- 
ample, butyleuu  and  tin*  amyltnes  yit-Id  them  ou  treatment  with 
moderately  dilnte  sulphuric  acid,  although  ethylene  cannot  be 
eimibirly  condensed.  'Vhv  coiideoMtion  may  he  explained  1>7 
Basnming  tliat  an  addition-product  with  sulphuric  acid,  an  alkyl- 
mlphiiric  acid,  ts  first  formed,  which  then  reacta  with  a  aeoond 
molecule  of  the  olefiue: 

CH 


j;jj'>C:CH,  yields  (GH,),C— CH, 


lOSO.H  -f  H  nc  :  C(CH.).: 


(CHo,c-cn, 


HO=C(CH.).. 

The  Eimplf^^t  member  of  thi?  wriee.  CH,,  mtihyUne,  baa  not 
beoii  obUitne^l.      VariouH  utLttmptH  have  been  made  to  pnepuro  it : 


144 


ORCjtNic  CHf:ujsrtiY. 


for  inetunce,  by  the  removal  nf  HCI  from  methjl  cliloride: 

hsvp  ulwu\'s  n-siilifd  in  l\w  fonuution.  not  of  nn'tlijlene,  tint  ot' 

etbyk-uu,  two  ('il,-grou)i«  unitiug  to  form  a  single  molucule. 

Ethylene,  C,H.. 

12&.  Kthyletic  Ih  h  gas,  iiitil  in  usuullr  prepared  1^  heatings 
mtiturc  of  alcohol  mid  Bitlphuric  acid,  KthyUulpbtiriu  wid  is 
first  formed  (60),  and  docomposve  on  further  heating  into  ethylene 
and  mlphuric  acid: 

C.H.SO.H  =  C,H,  +  It,SO^ 

In  the  prepunition  of  ether  tlic  tempi-ruturo  ii  nob  allowed  to  ritie 
above  A  certain  limit,  and  fresh  i^cohol  n  coDtinnoUy  added,  but 
in  this  reaetioji  n  higher  tompentture  is  employed,  and  noaleoliol  i« 
added.  An  a  resiiil  of  thitt  Rtronger  hciiling,  siilphiir  dioxide  itnd 
carbflii  dioxide  are  produced,  and  are  retiioTed  from  the  ethylene 
by  vaslitng  it  with  dihite  alkali.  A  purer  prmliicrt  in  ohtaiiied  by 
dropping  ethyl  alcohol  on  phosphorite  ai-id,  heated  to  200',  and 
Bubseiucutly  raising  the  temperature  to  S30^". 

Ethylene  ean  nltio  bo  readily  prepartid  from  ethylene  hroiiiide. 
CjH^BTj.  hy  removal  of  ite  two  bromine  ntom^  This  is  ePIeelvd 
by  bringing  it  into  contact  with  a  copper-nine  couple  (29). 

Hthylene  poRsemteft  a  peculiar,  Bweetifih  odonr,  and  bnnts  with 
a  hnniiioue  ilame.  It  i^  slightly  folnble  in  water  and  in  aleotiol. 
Wbon  piiSHod  into  bromine  it  ie  quickly  converted  into  ethylene 
bromide,  C,H,Br,.  Il  is  readily  absorbed  by  ef>ucentrat4jd  sulphuric 
acid  at  170*^,  witti  foniialioii  of  ethyUnlphuric  acid.  It  in  a 
remarkable  fact,  diiieovvred  by  Sabatier,  that  a  mixture  of 
hytlroficn  and  etliylene  is  changed  completely  into  ethane  when 
pasfied  over  finely  ■divided  nickel,  at  temperaturos  of  leea  than  'iW 
(29  iind  133). 

Amylenea,  L\H„, 

126.  A  mixture  of  isomeric  amyleiiee,  together  with  peril«iif, 
U  tecbnieally  prepiirwl  by  beiitilig  fusel  oil  (47)  with  zinc  cblnridc. 

The  isomerii?  amylenes  can  lie  Bi'paratwl  by  two  methods,  which 
are  also  applicable  in  other  itimllar  caaed.  Due  uf  these  \»  hnsvH  un 
the  eoluhility  of  some  of  them  in  a  mixture  of  etjual  vulumea  of 
wAti>r  and   concentrated   sulphuric   acid  at  a  low  tenipcmture, 


THE  NATURE  OF  THE  DOUBLE  CARBON  BOND.  MS 

Thereby  amylBulphnric  acid  is  formed,  whereas  the  otliers  are 
insoluble.  This  treatment,  however,  converts  a  part  of  the 
amylenes  into  condensation-products,  called  diamykne  and  tri- 
amyleae.  The  other  method  of  separation  depends  upon  the 
different  velocities  with  which  the  isomeric  amylenes  form  addi- 
tion-products with  hydriodic  acid. 

The  Nature  of  the  Double  Carbon  Bond. 

127.  In  the  foregoing,  the  presence  of  a  double  carbon  bond 
in  the  alkylenes  has  been  arbitrarily  assumed,  although  the  linkage 
in  nnsaturated  compounds  can  be  represented  in  a  variety  of  ways, 
which  may  be  summarized  as  follows: 

1.  Existence  of  divalent  or  trivalent  carbon  atoms: 

n  III        III 

GH  — C— CH, ,         CH,-^'H— CH,. 

S.  Existence  of  free  bonds,  for  which  there  are  two  possibilities: 
a.  Free  bonds  only  on  one  carbon  atom: 
CH.— C— CH,. 

J ; 

J.  Free  bonds  ou  different  carbon  atoms: 
CH,— CH— CH.. 

3.  Existence  of  double  carbon  bond : 

CH.— CH=CH,. 

4.  Existence  of  a  closed  chain : 

CH.— OH.. 


CH, 

It  was  stated  in  123  that  nnsaturated  compounds  are  con< 
vertible  into  saturated  compounds  by  addition  of  atoms  or  groups. 
The  constitution  of  these  addition-products,  on  the  one  hand,  and 
che  method  of  formation  of  the  unsaturated  products  obtained  by 
the  Bplitting  off  of  a  haloid  acid,  etc,  from  the  saturated  com- 
ponnds,  on  the  other,  allow  a  decision  to  be  arrived  at  between 
these  four  possibilities. 


I4fi 


ORGANIC  CfiBMISTRY. 


It  shoulil  bo  obeerved  that  tlio  sdililion-produrt  is  the  same, 

whether  tlie  exietene«  of  a  rfivaleui  c&rhoii  aloiu,  or  of  two  fret- 

bonds  on  the   same  carbon  atom,  be   asaunied.     For  example, 

II 
whether  propyloDc  bo  enpposed  to  have  tho  constitution  CH^>  V  •  CH, 

or  Cirj-C-CH,,  the  addition  of  bromine  prodocei   the  Hinu> 

fiitlistaiice,  ('II,  •  CBtj-  CH,,     Similarly,  the  iiBsnmption  of  triraient 
carbou  atoms,  or  of  free  bondB  ou  difTert'iit  carbon  atomttr  Icmda  to 

in       ni 
thoaamo  rt-Biilt;  thus  CH,-C'1I,  with  two  trivalent  carbon  atoms, 

and   (.!II,-C1I,,  with  fi'fc-  boiuk,  mit^il  viold    iho  siimv  additioii- 

product  with  bromine.  CH,Br-CU,Br.     It  follows  that  for  th« 
present  it  is  nnneceBsary  to  treat  oft«os  1  and  3  sppiinitely. 

It  is  tfoay  to  show  that  addition  does  not  takr>  plaee  at  nnv 
cuhon  atom  alone  of  unsaturated  compotindu;  fur  if  this  were 
to,  cthyleuo  chloride,  C,II,ri, ,  would  'have  the  oootttitution 
CK,-<'lk'],,  and  cchvk-nt-  itwlf,  ('K.ril.  Ethylene  rhh-ride 
would  tlien  bu  identical  with  th«  produel  obtaiuud  by  the  action 
of  phoKphorns  pentaohlorido  ii|kiii  aldehyde,  CH^-CJIO,  siiioo  the 
exchange  of  thi*  otygen  atom  in  tho  hitter  for  two  chlorine  ntomrt 
yields  a  eompoiiml  of  the  formula  f'lI^-CIICI,.  But  ethylene 
chloridu  in  different  from  the  ix)mpoiind  r,U,Cl^  (HAiffitleHC 
thiuride)  obtained  fnmi  aldehyde.  Similarly,  propylene  ohloridc, 
C,Il,l'l, .  obtained  by  the  addition  of  chlorine  to  propylene,  is  not 
identical  with  the  reaeiion-produrt  obtitinod  by  treating  acetone 
with  phnnphonis  peiitaohlriride,  <.!l(j-<.'Ci,-C!I,  {dtloroarpfpne},  nor 
with  that  from  propionaldehrde,  Cn,-CII,-CIICI,  ( propyUdtnt 
chlorifle).     Kthylene   therefore   eannot    hare  either   the  formula 


OH, 


i-U 


or    (-'Ilj.Cll,    nor    propylene    any    of     the    fonuubS' 

CH,-c-cH„  cH.cir.cH,  cUjtcir,,  or  cn,.cn,-(!n. 

N  :■ 

A  further  inei^ht  into  thi;  strueture  of  the  iirisatnrnted  eom- 

ponnds  is  dchTod  from  a  eoneideration  of  the  followinj;  facts. 
Propylene  iii  obtained  by  the  elimination  of  HI  from  M-propyl 
iodido,  ('H,-('IIj-CH,I.  The  same  compound  in  obtained  by  the 
removal tjf  111  fnim isopropyl iodide,  CH,'CIlt'C'U,.  lleni^e,  it  fol- 
lows that  propylene  oiunot  have  oithvr  tho  formula  CI1,-C1^I,-CU, 


THE  NATURE  OF  THE  DOUBLE  CMRBOfJ  BOND. 


M7 


or 


I 


n 


CH.— CH, 
\      /      ,  Mid  therefore   the    remaioiiig    posaibiHtiM    are 


CH. 


in     m 


cn.cii-cn.,  cu.ciicn,,  «n.i  rn.-oir :  cir,. 

Igobutyime,  C.H,.  U  similarly  o1)taiu«J  b}-  the  t!liniination  of 

HI  Jrom  both  iaobulyl  iodidf,  fCH,),Ci'H]CHJT| ,  ami  Irimethyl- 

carhinol  iodide,  (CTIJ,Cll|-Cn,'lI|.     Thns,  iaobiitylpne  can  only 

III  m 
hnve    one    of    the    formuljB    (CILkC-CII,,    <CrL)-C.CI!,,    *iid 

I    ; 
(CH,),0  :  CH,.     These  fwo  «xampteH  hHow  that  t}te  removal  of 

hflhid  aeid/rwH  an  aHt/l  hnlule  tukts plact  in  SMch  a  way  (hat  tht 

haloym  atom  and  the  hydrogen  atom  rrspertively  split  afffrom  ttsc 

carboH  atoms  tchich  arc  direcihj  linked  to  each  other. 

Tho  fcUoviuj;  examplee  will  servo  to  further  iUtigtrate  this  gcn- 

(■■11 
eralrul«.     If  III  be  removed  from  pentyl  iodide, .',  ,f  >CU'CII,I, 

tho  amylen«f  C',H„,  tbiui  formed  should,  in  uccordanc-c  with  the 

ntle,   have  tho  vonstitutiou  p  ,f  >('-CH,.     This  is  in   focb  th« 

>.'U     I     I 

case,  because  the  addition-proiUirt  obtained  by  the  actioa  of 
bydriodic  acid  on  this  amylenc  is  not  the  origiual  pentyl  ioilide, 

hot  one  with  tho  fonnuht   f>./>Cl-ClI,;    this  ia  proved   hy 

replacement  of  I  by  Oil,  and  conipariaoii  of  the  tertiary  alcohol 
thns  obtained  with  that  having  tho  aome  formula  prepared  in 
aocordanoe  with  the  method  of  iiynthesij  deacrihed  in  111. 

Th«coiieliUitioiiefaiuiihfr|ionty!  iodide,  (CHjl.CII- CI  I, -(11,1, 
whifb  yields  CjH,j,  mi  fUmiuiitiou  of  HI.  may  be  ttimilsrly  estah- 
lifihed.  This  aiuylene  yields  irith  HI  auoiher  peiityl  iodide, 
(CII,),CH-Cni'Cn,,  tho  ronstitution  of  which  is  provwd  by  its 
conreraioii  into  an  alcohol  whjoh  yields  a  ketone  on  oxidatiou,  aud 
is  ihi'fofore  a  seiwudary  alcohol. 

Bcn.Kiiow  has  shown  that  tho  splitting  off  of  a  haloid  noid  «unnot 
take  place  when  the  bslogoD  atom  and  hydrogen  atom  »Tti  hoc  linked 
to  carbon  atoms  in  juitapoBition  to  one  nnothor.  He  ntnTtt'd  from 
[sobntjlene,  (OHi),C  ;  m, ,  which  ylul<l»,  by  iulditton  of  two  brominu 
atoms,  (CM.)(CBr-Cn,Br.  Ellniiimtlon  of  IIBr  fn^m  this  dibromide 
produces  (CII,)|C  iCIinr,  till:  ■.■ciiHtihtlioii  of  which  follows  from  ila 
eODTUtsloa  luto  a«ot(>no  hy  oxidnlioTt: 

(CH,),Oi:CllBr  ^.  (CH,),0O. 


14^ 


ORGANIC   CHEMtSTRY. 


II  hu  not  been  fouml  piieaible  longain  split  ofT  11  Br-  from  the  compoiiad 
(CH,l,C:CJIBr,  ruaitobromotnUlfieiK,  in  whioh  lliare  is  no  liytlrogeti 
llnkwl  III  tho  carUiti  »[om  tlireutly  uunnecteil  to  lln'  rHItr-i^u|>. 

128.  It  iR  Re«n  from  tho  torcgoinf;  that  only  three  poecdble 
coostitutiunal  forinuhu  rt^iimin  ftir  the  iiU:i»LunitEHl  hvilmmrboiui. 

1.  Two  free  bundti  on  two  cnrboii  aloniK  Jirei'lly  liiikvil  t»  on(» 

another:  R.Ctl.OU.R'. 
I        I 

2.  TriTalent  carbon  atoms  direetly  liiikojl    to   oue  ntiother: 
CI       Itl 

B-CllCIMt'. 

3.  A  don  hip  b*»nfi  betwoen  two  carbon  ntomK:  ll-CH  :CU.R'. 
The  preferpnre  is  given  to  tho  fommln  with  the  (loiihlo  bond 

for  the  following  remioiia.  In  the  first  pWe,  it  would  ba  remark- 
able if  tma  b«ii(lB  or  trivalent  wirhon  atomn  ronld  only  ort-ar  in 
juxtupoftitiou  to  one  unothor,  that  it;,  if  rarbon  atoms  which  are 
not  directly  linked  togethc-r  could  not  have  free  bonds,  or  bo 
trivalcmt.  .Second,  cxporioiipe  has  shown  thnt  nusatnrntcd  coin- 
ponndK  aontnining  an  nuevcu  number  of  fri*o  bonds  flr  Lrivalent 
carbon  atoms  do  not  eJcirt.  Kext  to  the  saturated  hydrocarbons 
CuH^  I ,,  oomo  in  order  of  the  number  of  their  hydrogen  utoni!!, 


etc.      I [ydrocarltone,   ('„!! 


in  which  one  «r  thT««  froo  bonds,  or  triTalont  carbon  atoms,  eonld 
he  -iiuppoiiei]  to  be  present,  do  not  pxist,  all  uttoinpts  to  iBoIat« 
methyl  CIl,,  ethyl  C'.IIj,  etc.,  having  totally  failed.  Thus  no 
support  h  to  he  found  here  for  the  asBumption  of  either  free  bonds 
or  of  triralent  carbon  atoms.  On  the  other  haml,  both  facta 
admit  of  a  ptrfeotly  niitiiriLl  explanation  when  the  oxistence  of  a 
double  linking  is  aasitmed,  sinw  in  this  ciwe  the  eliminalion  of 
haloid  ncid  nitixt  take  plneo  from  tbo  carbon  atoms  diroctly  hnkod 
to  one  another,  and  comjiounds  am-li  ae  C„n,n^,  could  not  occnr. 
The  antiiimpiion  of  the  douhle  bond  is  therefore  the  only  one 
cnpablo  ^f  giving  expresaion  to  the  obeerred  facts- 

The  non-existence  of  froo  hoads  in  the  anaatorated  hydro- 
carbons has  led  by  analogy  to  tho  conclusioTi  that  tliey  are  also 
ahscnt  from  other  compounds  ouutuining  bIuuih  doubly  linkud, 
trebly  linked,  etr.,  eiich  as  nitrogen  in  ibt)  nitrile«,  uiygen  in  tbfl 
ketonfs.  etc 

129-  The  assnniption  of  tlii^  exIgtcucD  of  nmUiplu  bonds 
pro6«»ta  at  first  sight,  however,  imrtaiu  difliculti<'t(  wlieu  the  power 


forming  mMitioii-productB  poascsawt  by  all  soch  Rompouiiiia  is 
cousiilercil.  It  has  been  stated  Bevcral  times  that  carbon  bonds 
are  ouly  brukon  with  ilil1ir>uUy  (40),  but  in  tlutt  iraso  tbu  drkiible 
carbou  bom]  is  very  easily  converteil  into  ii  ttinglo  one  by  formation 
of  m  adilitiou-proilucL  It  ik  Htill  morti  romnrkabln  that,  when  a 
fubscaoce  conluiDin^  a  doublv  bum)  In  ttit  imrboti  rhiiiti  id  oxidized, 
tlie  chain  ehuiiM  ulwavK  W  broken  ut  the  position  of  thp  double 

■  bond.  A  Batisfactory  cxpbmation  of  this  i^  aflordt-d  by  tho  fact 
that  in  many  ciiae^  in  wbi^'h  eubstanci?!!  containing  n  donblo  carbon 
bond  are  oxidized,  it  h  posKiblc  to  nhow  that  tU&  brcakiug  of  the 
carboj]  chain  at  th<>  paint  where  the  double  bond  i»  prettent,  does 
Iiot  ocwur  dirvctly.  but  tbtit  un  addition- prodnct  is  first  formed  by 
Kthe  taking  np  of  two  Oil-groups,  it  bt-ing  ofti-n  possible  to  isolate 
^Blliia  prodnot: 


becomes 


\CHOU 


/ 


ClIOlI 


Since  oxidation   takes   place — in  accordance  with  the  general 

rutv  in  49— at  a  jioint  where  it  has  already  begiin>  it  follows  that 

^_iri  thia  caw  fnrtlior  oxidation  mnst  result   in  a  breaking  of  the 

^■ctrbou  clmiu  at  the  point  whore  the  donble  bond  originally  existed. 

^  Thua,  tlie  brtjiking  of  Uio  iinsalu rated  oliaiu  by  oxidation  dopi-udd 

^^on  the  fonnation  of  att  intermedialo  uddiliou-prodiiet,  and  it  iB 

^■therefore  only  ni^jcaiiuiry  to  fiud  an  explanation  for  the  ciise  with 

^Kn'hich  thin  is  t-ITerted.     Tliia  can  be  best  arrircd  at  by  a  considera- 

^Bliou  of  the  uutuiv  of  Ibi;  bouds  between  the  atoini<.     An  aflinity 

^Bor  bond  may  hv  looked  upon  as  an  attraction  exercised  by  one 

^^  atom    QpOQ   another.     Should   an   atom    poaeess   more   than    one 

^aflinity,    il    i*  ussunied    that  the  attraction  is  oxereiswl  in  mor« 

^■than  uQo  direction,  aiid  is  coii'Oentrated  at  certain  jwints  of  its 

^nurfaoe,  Bomevhut  after  the  manner  in  which  the  attraction  cxer- 

^Vci9<^d  by  a  mtignet  ia  concentrated  at  its  two  poles.     Any  other 

aa*nmpcion,  ftnch  aa  that  the  attracting  force  if;  equally  difttiibuted 

over  the  whole  surface  of  an  atom,  wuubl  miike  il  dilBmlt  to 

understand  why  each  ek-ment  shuulil  have  u  dulurminate  valency. 

If  the  carbon  atom  is  ictruvulLMit,  there  must  bo  on  its  niirface  four 

Mch  points  or  "  polce,*'  situated  at  the  uuglca  of  a  regular  telra- 

h»drop  ($3).     In  the  case  of  a  single  bond  botvooQ  two  such  poloa 


150  ORGANIC  CHEMISTRY. 

on  dilferent  carbou  iktomi,  tbeir  miitaal  attraction  would  caaso 
thuin  to  spprnacli  one  another  ao  cJoBcly  a«  jiossiltlp. 

Ba£TEB  hue  put  forwurd  the  etippoeitioii  thnt  tbe«e  polos  on 
the  6urrace  of  CHrl:>on  Atoms  nro  movable.  Knch  n  movement 
rw!«Us,  howpver,  in  a  (certain  "  tonsion,"  which  tends  to  bring 
buck  the  poleH  to  their  origina.1  poHitioii.  For  example,  when  a 
singld  honci  between  two  curlioD  atoms  \a  converted  into  u  doable 
one,  the  dircctiolu  of  the  aftinitiee  of  eiich  of  the  two  curbon 
Atoms  inuBt  undergo  iiii  Hpjirt-c-iitblu  ulttiriition: 

Tho  tension  resulting  from  this  is  therefore  a  cuiii^  of  the  eane 
with  which  dou1>le  Liouds  can  bu  broken.  We  ahull  ciee  Intor  tlutt 
Baetbr's  teu9it/»  Ikevry  also  ofTordg  nii  cxpItin»tion  of  other  im- 
portuiit  pheDomena  (262). 

li  is  «««n  from  the  foregoing  that  the  double  bond  must  not  be 
regarded  as  a  more  doubling  of  tho  isiugltt  one,  ua  the  exproBsion 
"  double  bond  "  would  indicate.  Jtt^ 


II.    POLTHXTETLEHE  COHPOCRDS  C„nt„. 

130.  Isomeric  with  the  olefines  ia  a  series  of  coniponnda. 
C„n,„,  chiefly  iiiBtiiigiii3he<I  from  the  former  by  tlie  absence  of,  or 
■t  least  a  diminution  in,  the  power  of  fomiiug  udditiun-prodncts. 
MoBt  of  these  componndB  are  very  sUible;  thus  peutamethyleue, 
C,I1„.  bears  a  strong  re*cmhlanco  to  »j-pentam',  ('jH„.  It 
will  be  eeen  loUtr  (260-S63>  thnt  tho  methods  for  the  formatioD 
of  thoj^  eompoiitidii  net'enaitnte  tho  a«aumptton  of  A  closed 
Cftrbon  nhniii  in  the  moleeiile. 

HL   HTDX0CABBOII8.  r„n,»_,. 

131.  A  variety  of  structureH  is  possible  for  these  eomponndfi, 
which  contain  four  hydrogen  iitoms  \v6s  thim  the  corresponding 
paraffiuB.  Thug,  hydrocarbons  containing  two  double  bonds  have 
tbo  general  formula  C„Hj„_,,  for  example, 

OH,:CHCU:CII^ 


« 


MYDHOCARBOWS  tVITH   TRIPLE  BONDS. 


»5' 


Fiirt)i«T,  Btib6tanc««  coQt«ining  a  irip\«  bond  hare  also  tho  sani« 
empiricnl  compositjoD,  for  exnmple, 

The  reaeons  for  the  assuiuption  of  a  triple  linking  in  thOM 
rani[>oiiiii]g  «ri>  idetiliciil  witli  thone  which  led  to  the  Aflgamption 
of  the  clotiblo  bond  iti  the  oUQiivg  (128). 

A.  HTDBOCAItHOM^   WITH  TJitPLB  BOSDB. 

Nomeaolature. 

132.  The  first  memb«r,  C,ll,,  is  ciiUecI  ncelylme;  the  second, 
C,!I,,  niftflene;  th'P  higher  mpmberfl  are  generally  FBganled  aa 
subfa-ti tilted  acetjlenes;  thus  C',11,  ia  called  et/ii/laceiffle/ic,  V^ll^^ 
bvtiflncelylene,  etc 

Kcthoda  of  Formation. 

1.  By  the  dry  diBtillation  of  complex  componnds;  hence  the 
occurrence  of  acetylene  iii  coal-gas. 

3.  Uy  the  withdrawal  of  two  molocales  of  haloid  ftcid  from 
compounds  of  the  formula  C„]Ij„X,,  whoru  X  rt'presont*  tho 
ludogen  atom,  thoeo  compounds  Uung  formed  by  the  addition  of 
halogen  to  albyleues: 

CH,Br^OI-r  Br  -  SHBr  =  CHsCU. 

KtliyleOti  bruiiifUs  Ai^styleDO 

Thifl  IR  effected  by  heating  witii  alroholic  potoiih. 

A  general  method  for  tho  preparation  of  unsaturated  com- 
pounds \&  (urutfibed  by  thia  method  of  adding  on  hulugun,  folluwDd 
by  the  removal  of  haloid  iieid.  For  example,  etartiiifj  with 
C',Hp,.,,  CjH,„,,X  U  obtnined  by  tho  urtion  of  chlorine  or 
bromine.  Up-ating  with  alrohnlir  potash  nonvcrtK  thiK  into  ('uII^q, 
from  which  C„II,„Rr,  in  obtained  by  the  action  of  bn)mine,  atxl  is 
converted  int«  ("„!!,„  - ,  by  abstmctiun  of  211  Br.  This  cumpuiind 
cttD  again  form  an  addttiun-product  with  bromine,  aud  no  on. 

3.  I*y  lh«  abstraction  of  31IX  from  compounda  of  tho  formula 
C,H,nA,,  formed  by  the  action  of  phosphorus  pentJihiUide  upon 
aldehyden  or  ketones: 

CU.CUCl, -atlCl  =  CJI=t'IL 

Ethf  iMcn*  (lil'Tiili*  An>i^l*]i« 

CH,.CCI,CH,-2nci  =  CII.-CaCH. 

CulcHvaui-Kiiie  AllrhHM 


M4 


ORGAMC  CHEMISTRY. 


I 


AMtyUne,  (',11,. 

133.  Acetylene  i«  a  colourleM  gaa  of  disagreeable  odour,  it 
Bomewbat  soluble  in  vruter,  and  cuikdeiiswi  at  18'^  and  8:t  atmoa- 
pliervs  to  H  liquid  boiliug  at  —  83-4".  It  cau  be  8yutli<wi2«d  from 
Hi  elcmunts  by  meius  of  an  devtric  arc  botveeu  carbon  |m)W  in 
au  tttiuo8pb«TO  of  hydrogen,  a  small  rjuantity  of  inetlinnc,  and 
a  trace  of  ethane,  being  eitnultaneoasly  formed.  Hi  presence  cau 
be  detected  by  luoans  of  an  ammoDiacal  Folntion  of  cuprous 
ehloridi-,  which  yiulds  a  red  precipitate  of  copper  acetylene  even 
whou  tnires  n[  ii('i>tyl(>ne  are  mixed  with  other  gssEO.  Acetylene 
is  altfo  oIit;tined  as  a  pniduct  of  the  inconiplelt?  uombustian  of  macy 
oi^nie  Mibstanrvs.  It  is  prt-pared  un  tlie  lurtpj  scalu  by  the  action 
ol  waltT  on  ealcium  mrbidt-,  or  ciik-ium  ucetylunu,  CoO,: 

CaC,  -t-  2U,0  =  Cft(OII),  +  C,H,. 

The  re«ctiyn  is  aomuwlmt  violent,  and  \i  attended  with  evolution 
of  considerable  heat.  Calcium  carbide  ie  prepared  hy  heating 
curboii  with  <|Hicklime,  CaO,  in  an  electric  furnace.  The  cak-ium 
liberated  by  the  action  of  the  carbon  on  the  quicklime  enters  into 
eomfaiuatiou  with  the  oxoess  of  carbon,  under  the  iniluence  of  the 
high  temperature,  and  forms  calcium  carbide,  which  is  white  whim 
perfectly  pure,  but  hu»  usually  a  dark  rcddiah-brown  colour,  due 
to  the  prcaencc  of  Huitdl  <^uantitice  of  iron. 

Aculj'Imio  can  bt*  iiraiMir«>cl  iil.  n  nioflunta  cost  by  this  melli'Ml,  nml 
atlempta  linrc  l>o«a  iiiadc  to  use  it  far  lighting  pnrposa.  aa  a  stream 
of  tbo  gaa,  poitBL'tt  ibroBgh  a  fln«  opetiitig,  bums  witt  an  iatftniu^ty 
lutninoiin  fliiini!.  Tptotlie  |>re»eut,  rliviieAlteiiipCfthavebeeii  ■Itcndrtl 
by  illl1l<nilili»(,  piirtly  onlnff  to  the  cost  of  praduclion.  but  mnre  in  lite 
nature  of  nccljlcnu  llsclf.  It  tomiB  csplotslw  copper  ncL-lylt-Do  with 
tbe  cop|H>r  of  tbo  ga»-fi<tiiigs:  a  iniilur(>  with  air  explodes  with 
extrome  Tiolaacc.  and  is  niiich  mora  dangproua  than  a  mixture  of 
ordinary  coal-gas  and  air.  TbU  is  due  to  th«  fact  that  aiucb  lioiit 
ia  Inkeu  up  in  the  formalioiiufacotylcnv,  ihiscomponDdbvin^itlronKlj 
en  do  the  nil  tn  ("  Inortfiitiic  ('licmistry,"  STj.  In  nclditiou  to  Ihjs.  ihc 
liiaile  of  i-xplnsiou  arc  much  wider  than  for  any  othc'r  gas.  nn  i^xplo- 
aivD  mixtiiru  being  formed  with  air  by  the  admixture  of  3'8?f  of 
acetylene,  whila  in  tbo  ca*«  of  Goal-Kafi  tbe  lioiiu  arc  ouly  &-3df. 
The  Teloeitjr  of  propa^tion  of  coiobastlon  Is  also  mueli  greater  in  the 
case  of  aoetyleno,  and  this  uugmeufat  oouidvrabty  tbe  foreo  of  the 
«xpto8lon. 


HYDROCARBONS  IVITH  TWO  DOVBUt  BONDS.  I55 

Acelvleiie  prepared  frutii  CitlciUtn  carbid«  soiiMlini«s  conUiiiH 
kll  qunntiltsA  nf  kulptmroltcxl  hydrogen  and  pbospborotted  bj'dro- 
g«ii,  i»  wliioh  ilnwea  ils  ditajtreeobk'  6dicI).  It  uiiii  be  frt^ed  from  Ibe 
fonnur  b>  a.  aoliitiori  i»f  ciiuaiic  »lkNll.  aud  from  tbo  lattur  \)j  a  »«4n> 
tion  of  corroetre  £ublituat«  In  hydrochloric  Mid  Thu  rcmorul  of 
plio«plioretb>d  hydrogen  :s  of  special  importsncf,  »iiic«  ils  prcseDCo 
nuiy  Iwkd  \o  t)i«  Kix^ntancons  ii;nitioa  iif  the  gns. 

By  Ihv  diffi't  tiydroKenntion  of  acetylniB  Id  presence  of  Fnlciced 
njckol  (Wiiiid  lU).  Sasitieh  nnd  Skm>brkks  ba.ve  obtained  liquid  mix* 
lURS  of  hydroc:irboiiK  wliicli  can  Ijc  [tiitiln  lo  corrf^jHiiid  either  with 
American  or  C«ucaaijin  pftroloiim  by  varying  lhi»  iwnditionii  of  ths 
experimenl.  To  account  fortbe  formaliou  of  petrolotim.  ihcy  lunumc 
that  thero  arc  in  lh«  interior  of  (be  oarth  froe  nllcnli-mptKls  and 
mtlallic  carbides,  which  in  coniact  wlUi  water  give  riao  lo  tnixiurcs  of 
hydrogen  Ami  h]rdn>carl>on.>«.  Tb«ae  gaaes  encounter  finely -divided 
nickel,  cobalt,  or  iron.  aii<I  tlnus  ykld  the  niixturva  of  hydrooarbona 
coDgtiiutitig  natunil  pulrol«um  (H). 

IL     HYUIIOI'AKBONS    WITH   TWO    DODBI.K   BONDS. 

134.  nydn>cjirbon»  with  two  double  bonds  tiavo  been  compan- 
tlroly  liltio  Invntti^tod.  AiUue  \*  obtninixl  from  tTibromopropano, 
CIIfBr-CflBr-CiliBr.  by  rauoval  of  lIBr  by  nipans  of  potaali,  and 
BuhsM^uenl  tre.ilment  of  the  dibrotno-componnd  thus  f<irmr<(l  with 
tine-dust,  which  removes  tho  two  romaining  bromine  atoms  (IM) : 

Ca,Br-CHBr-CH,Bf-»CH,:CBrCU,Br  —■  CH,:C:CH,. 
TnbrDmapropaiie  WbromopropyleDo  Allnia 

Its  oonatitntion  follows  from  ttiis  motbod  of  preparation.  It  is  a 
colourlna  gaa,  nnd  unilka  the  inomeric  altyleae,  OHi  ■  CeClI.  does  not 
yk-IJ  KKtalliodorivativeB  {188). 

IHitlltjl.  OH,:CII.t'H,.C:H,-OII:C;Ht.  Ih  obtained  by  the  rcUob 
of  AOdiiitu  npon  allyl  tWi</(,  CEIi.CII-CIIiI  \\ti\,  from  which  It 
ftdlavrsibat  tl  tius  thu  cuiitdiluiion  indtcnu^-d  by  ibr  above  foruiula. 

A  hydrocarbon  of  this  scries  of  theoretlcat  importanco  U  i»oprw9, 
C*1I*.  It  b  obtained  by  tbi;  dry  distillatioii  of  caoutchouo.  nnd  is  a 
li(|uid  boiling  at  'il'.  By  llio  union  of  two  or  moro  mo1conle&.  It 
pussM  into  terpeiipj*.  C>«H„,  CnH,.,  elv.  tt  Ib  convened  by  <!on. 
««iilrat«d  hydrochloric  ncLd  into  a  cubscanoe  strongly  rwtumbiing 
caotitobouo,  perli.-ipa  identical  with  iL     Isoprone  is  provijd  lo  haw  iha 

eoostiluiion  ^[J'^C  CU=CH,.    by  ibo    addition    of  SUBr,  whloU 
leldsAdlliroinida.  ^g'>CBr~CII,— CD.Br,  identical  with  that  ob- 
tained from  ditnetbyUilleiic,  ^^[>0=O=0H* 


J^ 


miMtlTttttOll  PKODVOTfl  OF  TBI   UVSATTOATBD 
KYOROOAIIBOirS. 


«■.**  V  .K\«*-V  i*  Vn-'N'VwA-MWit^V^  Wn-«  :a*B,  tan  :aaCMSiaasa! 


■*N.-     .-     -•,      •-— . .  -...7  - -V  •.     f   .;.  •-■     .      aftM&.-.^n: 


UHSATURATEO  H/*LOGEN  COMPOUNDS. 


«5: 


i 


methodf)  by  which  thciic  compoimils  an?  obtninetl  indicai« 
that  the  halogen  ntoni  in  thc-tn  w  linked  to  s  mrbon  atom  buvitig 
a  double  bond.  Thi^ir  iinipcrties  differ  widuly  from  those  of  coin- 
poiiiidii,  Kurh  ns  tho  tilkyi  hiilidc^,  in  wluoh  thu  hulogon  Atom  it 
hnked  to  a  carbon  utom  having  nnly  ^nglo  bonds;  and  thia  nilc  ie 
generally  nppli«ible  to  oniripoiimisi  of  thia  kind.  Tho  halogen 
atom  of  the  nlkyl  hnlideK  is  ejip4M-ial)y  siitited  for  taking  part  in 
doable  decompositions,  htning  rBphiceahle  by  hyilrnxy],  »n  alkoxyl- 
gronp,  an  acid -residue,  thp  iimido-groiip.  etc. 

This  apfiitide  for  tloHbh  (lecotHpotitinii  is  ahiwt  n'holli/  wanting 
in  compounds  tckoi't  halugm  atom  is  linked  to  a  carbon  alom  with  a 
rtoubie  boml.  Alkalis  do  not  <*onv<'rt  thpm  into  alcohols,  nor 
ulkoxidee  into  ethere:  hnt  inrariably,  whon  a  reaction  doce  tiiko 
p1ac«,  a  haloid  acid  ift  uplit  off,  with  formation  of  hydromrhong 
of  the  eeries  C,.U,„  ,. 

An  ifiomer  of  a-  and  fi-chhropropylef^e,  which  have  been 
referred  to  above,  id  called  aflyl  chloride.  The  halogen  atom  in 
tliia  L-om[iuiind  tiiki*^  purl,  in  double  dooonL|)oaiiiuiid  as  eosily  as 
tliat  in  au  alkyl  eliloride.  Allyl  eltloride  is  obtained  by  the  action 
cf  phosphoms  ]>enCachIonde  upon  allyl  alcohol,  which  can  be 
Hrepared  by  B  method  to  be  drsrribpd  Inter  (168).  This  alcohol 
yields  M-propyl  alcohol  by  addition  of  hydrogen,  and  its  hydroxyl- 
jgroap  must  therefore  bo  at  tho  end  of  the  carbon  chain.  Henoo, 
th«  halogen  atom  in  allyl  rhloridw  mn«t  aUo  be  attacihod  to 
Llw  end  of  tho  ohaiii,  titico  it  takes  the  placu  of  the  hydruxyl- 
^Toup.  Given  tho  constitutions  of  a-  and  /^-[iropylvno  chloride, 
which  are  dedtiwd  from  that  of  propionaldohyde  and  acetone,  the 
»Ilyl  hnlidea  c*n  only  luivo  the  i-onBtilntinnal  formula 

Jleru  the  hihlogcn  atom  isnttHohed  ton  Kiiigly-linki'xl  r-arhon  atom, 
aud  retaiiiit  its  uormal  character  in  spite  of  tlie  proaunoe  of  a 
doubh-  txind  in  tho  moW-ulo. 

This  dependence  of  the  charneteT  of  a  halngon  atom  on  its 

iHMtitiou  in  the  molecule  of  an  uumtunited  nomponml  affonls  a 

kuieana  nf  determining  wlielhcr  it  is  attai:hed  In  n  cingly-l inked  or 

dotibly -linked  carbon  alum,  by  a«certuining  whether  it  does  or 

doci  not  po«eo«  the  power  to  take  part  in  double  dceompositioDs. 

Tho  following  are  examples  of  individual  members  of  tho  serin 


fiUBSTrnrTIOH-PBOBUCTS   OF  THE   UHflATTTHATED 
B7DB0  CARBONS. 


V 


"^  t  ima&TiraATES  halooev  coiiMinrDB. 

130.  SInre  Ch«  sHtnmttHl  hyclmnftrliong  thomsielTes  ilo  not 
poKM^  any  mlient  charactPriRtirn,  the  properties  of  thvir  com- 
poandH  (lttp«ni1  upon  the  nature  of  the  snbfitituttng  Bl«tnents  or] 
groupn.  Hitherto  we  h»Ye  otilv  rotieiderctl  rotnpotinda  whosej 
properties  are  iluc  to  the  presenre  in  the  molecule  of  u  single 
group,  hydroxyl,  curboicvl,  a  multiple  carbon  bond,  etc  Wo  have 
now  to  deecribeBubBtaticofl  containing  more  thnn  one  eharaetcrigiic 
group  ill  the  molecule. 

^\'hen  thees  groups  nre  present  simultaneously  in  the  samdi 
Dioleeiilo,  they  generally  exerriso  a  niodifring  influence  upon  one 
another.  The  extent  of  this  inflnenre  rarica  considerably,  aa  will 
be  seen  from  a  consideration  of  the  different  cJaesea  of  nneatniat«<I 
halogen  compounds. 

Halogen  derivatives  of  the  type  C,H^^jX  are  obtained  by  the 
addition  of  halogen  to  the  hydrocarbonB  C„H^,  and  iabBequont- 
abetraction  of  one  molectile  of  haloid  acid ; 

CH,=Cn,  +  Br,  =  CH.B^-Cn.Br. 
CH,»r— CH.Br  -  llUr  =  CH,=CHBr. 

KiIii1pii<i  hioiiifilr  Yliijrl  liNititlilR 

They  are  also  formed  liy  removal  of  one  molewtle  of  haloid  acid 
from  compounds  i:ontaining  two  halogen  atoms  linked  to  tlie  sume 
carbon  atom : 


OHj.cn.cHci,  -  nc]  =  ch,-ch=chcl 

CH,-CC1,-CH,  -  nCl  =  CH  =CC1— CH, 

ChloroAertooe  ff-OMorvpravTl«n« 


tS6 


1 


VNSATURMTED  HMOGl 


I 
I 


Tho  methodR  by  which  Ihpse  compoimilx  arc  ohtiiiiie*!  itidicnte 
that  the  lialogen  atom  in  them  in  linkoil  to  a  uirhon  utom  huviog 
a  iloable  bond.  Their  prnperticji  differ  widwiy  from  those  of  com- 
poiinds,  such  ae  the  ulkyt  huHileB,  in  which  tliu  halogen  atom  is 
linkod  to  a  carbou  iitom  having  only  single  bond*;  and  tiiis  rule  ifl 
genenlly  applieablo  to  eompoiini]?  of  this  kind.  Tho  hnlogen 
ntom  of  tho  alkyi  hiUides  is  OKpooially  snitpii  for  t»king  jwirt  in 
double  docum position 8,  being  Tephiceahle  by  hvilroryl,  an  alkoxyl- 
gTOiii>,  an  acid-residne,  the  amido-gronp,  etc. 

This  apiifitde  for  double  dec<impo»itinn  is  nlmoitt  wfiollij  wanting 

in  c&mpOHHdi  whoKe  haiogen  atom  is  UnXxd  to  a  carbon  atom  with  a 

I  d<fHblo  i^ttd.     Alknlie  do   not   ennvart  thorn   into   alcohols^  nor 

alkoxid«£  into  others;  hut  invRrinbly,  when  »  reaction  does  take 

|])lace,  a  b^loid  acid  is  split  off,  vith  formation  of  hydrocarbons 
of  tho  aerUas  C'„Hp,_,. 
An    UoRier  of  «-  and    ff-chlDiopropyhnfi,   which  have  beon 
roforred  to  above,  ia  t-allod  aUyl  (khridt.     The  halogen  atom  in 
tluH  compound  taked  part  in  double  decompositionu  m  easily  us 
t)iac  in  an  alkyl  ehloridt>.     Allyl  ehloridu  is  obtiijnud  by  the  notion 
^^  of  pbuHpborus   penUiehioride  upon  allyl  alcohol,  wbieb   can  be 
^B  prepare*!  by  B  method  to  be  deecrihed  later  (158).     This  alcohol 
^^  }-ielrU  M-propyl  ali^fth"!  by  addition  of  hydrogen,  and  ifcfl  hydroxjl- 
^^  group  must  therefore  fee  at  the  end  of  tho  carbou  chain.     Uence, 
^H  tbo   halogen   atom    in    allyl   L*hlorido   must  also  b«  attatibed   to 
^^  the  oml  of  ibe  ubain,  siutw  it  takejt  tho  place  of  the  Iiydroxyl- 
group.     (iiveu  the  roiistLlutioiiK  of  tr- and  /)-propyleiio  clilorido, 
which  are  deduced  from  tliat  of  propioualdeliyde  and  acetone,  the 
ftllyl  halides  can  only  have  tho  ronatitiitional  formula 


I 


CH,=CH.CH,X. 


IFerr  the  halogen  atom  iri  attaohod  to  a  singly-] inked  carbon  atom, 
^^  and  rL-tuiii«  its  normal  characber  in  spito  of  the  pn;t»m:e  of  a 
^■double  bond  in  tho  molecule. 

^H         'V\\m  depcn<li!m'u  of  the  character  of  a   hnlngen   atom  on   its 

^K  pcmttion  in   the  molecule  of  an  iiuKatiirtitec]   compnnnil  affords  n 

'  nieanii  of  determining  whotbcr  it  U  Httaehwl  to  a  aingly-linked  or 

doubly-linked  eorbun  atom,   by  lucerLaiuing  wbethor  it  dne«    or 

doM  not  iMMM«s  the  pi^wer  to  take  purt  in  donblv  decompoaitioos. 

The  following  are  oxamploii  of  indi%'i(hinl  members  of  tho  sorice 


OfiGylWC  CHF.MfSTKY. 

Vinyl  chloride  CII,:  CHOI  is  n  gM,  vinyl  brmidt  CH,;  CHBr  ti 
liquid  of  ethereal  odonr,  Iktth  these  oompoiiiiilH  polToierize 
readily. 

Alhjl  chlori<le,  alli/J  brotuide,  and  alhjl  iotiidf,  boil  reapw^tiTclT 
at  HV,  70",  and  103".  Tlu-y  nre  often  itaod  in  »>utln*«i  for  tbc 
iutroduction  of  tin  uusatunitcd  group  iiito  u  compound.  The; 
Hato  a  charactoriAio  odour  re^mhling  that  of  iniirtArd. 

The  propart/yl  eompeunds,  CIt=C'-CH,X,  may  hn  moiitioned 
as  a  tT()o  nf  the  BcriPB  C„II,„  .,X.  Their  coniititiition  is  inferred 
from  the  fact  that  they  yield  motallln  derivatlvos,  showing  thut 
they  contain  the  group  0=11,  ami  also  becauHe  their  halogun 
afcom  is  capable  of  taking  part  in  doiiUo  documpoaitioiie,  und  la 
therefore  attached  to  a  Biugly-liuked  carbou  atom.  They  iiro 
obtained  from  propargyl  alcohol  (138)  by  the  action  of  phospbonu 
pentahalido,  ami  are  liiinide  pnesemTi^  a  pungent  smnll. 

Th«  comjintiiid  CI1Br;C.  bromoactlj/lidetie,  which  is  nnaiDcil  bj 
Kep  tu  cunljiiu  a  divHlviit  curbi>n  ntoin,  um  boobuiiimd  trvm  NceLyteu 
bromide,  C'llBr:  ClIBi-,  by  dvAtmcnt  mlli  nicoliulic  palAeli.  It  is  ■ 
gas,  taking  Are  sj>oQlanQauBl}r  in  tbe  air:  iu  Holutioa  in  xloobo)  ia 
pli«epl»>r««ceDt,  oiriDK  lo  slow  oxidation,  and  ttio  gas  itMlf  has  an 
odour  very  similar  to  that  of  phosphorus. 


U.    PHBATOSATED   ALCOHOLS. 


136.  The  hydmxyl-gronp  of  the  unaaturated  alcohols  may  be 
attached  to  a  oingly-linltod  or  doubly-linlied  carbon  atom: 


cH,:cn.(;ii,on, 


CH,:CH.OH. 


Very  few  compotinds  of  the  typo  of  vinyl  alcohol  are  bitown.  In 
the  inajurity  of  cai-c*  in  which  their  formatioE  might  bu  expected. 
their  isomore  arc  obtaiDcd.  Thus,  when  water  is  abstracted  from 
^yool,  CH,OII  ■  CH.OH,  there  results,  not  vinyl  alwhot,  OUOH, 

CII,  II 

but  Ml  iaomer,  acetoldehydp,    |      14  _  ^H, 


When  /if-broniopTopyleno,  CH,-CBr:CII,,  is  heated  with 
water,  there  is  formed  not  /S-hydroTyjiropylene,  CH,-C(OH):CIl,, 
bnt  the  isomeric  acetone,  crt.-CO'CIt,.  It  hiw  been  geDenUly 
obHerTed  that  in  raaex  in  wbieh  a  grouping  of  the  atoms  lu  the 


ORGANIC  aiEMlSTRY, 

Allyl  alcohol  maet  therefore  contain  the  group  — OH,OH,  which 
U  chanicteristio  of  primary  ak'-oliuU. 

AII7I  alcohol  is  a  liciiiid  with  itii  irriuttiiiK  odour,  soHtlifyiD^  at. 
—  50^,  and  boiliiifc  at  ^la-o",  and  ih  uiiacililu  with  water  iu  all 
proportions.  Its  apccilic  jjraritT  at  0  is  DiS^a.  It  forms  siidi- 
tiou-producl9  with  th«  Imlogens  and  witU^drogeu,  yivldiug  with 
the  lattvr  n-propyl  aloohal. 

Many  other  coiuiKiirnds  containing  thonIlyl-gn>i^CIIi:CU-CII)— , 
are  known.  Of  itieeo  all^t  tulphhie  (CM,:  CH-CHT)*S,  X\w  principal 
con&tllii«iit  of  oil  of  ifarlic,  imiy  >>«  nii^iituiiiMl.  It  'u,  flvuilietically 
obtained  by  the  aclion  of  poUusiiini  Huiiihide,  K|S.  on  allyl  iodide. 

We  have  seen  that  tho  influenoe  uF  the  double  baud  iii  the 
tineaturuttid  halogen  oompounds  und  uluufaols  ia  very  proDonnced 
when  it  is  eiLuutcd  iu  the  itnmmliuti-  Ufijjhhourhood  of  halugvu  or 
hydroxyl,  but  that  otlicrwisc  it  in  muuh  less  marked.  The  nile  Is 
that  when  ttev  groups  are  titmittd  in  immtxtiale  jrrorimUif  to  OM 
anothfT  in  the  s^me  molftcnU,  earh  group  eJt^rdtfet  a  slrong  injtufnes 
tipOH  the  properties:  of  the  other. 

Propargyl  Alcohol,  CH=UOU,OH. 

ISI.  Profxirijyl  ateotitl  conlaioa  a  triple  boud,  and  ia  pr^-pxrod  in 
the  follrtwlne  wny.  CnvBrCflBr  Cri.llr.  Iribromhjdrin  \\ii).  ia 
oonfertod  by  treatment  with  caustio  potash  into  CHi  !CBr-CHiBr 
Wheri  ireHttxJ  with  potAtMiniu  ;icvUtu  and  Itiuii  «i[ioiiifl^,  ihU  vtdda 
CII.  :0Br-C>l|01I,  tin<!»  only  tho  torminnl  Itr-ntoin  1«  capaMe  of 
taking  pure  in  u  doubU'  dniomposilioii  (ISS).  Whvu  thJa  alcohol  in 
ngain  brought  into  conlact  with  cjkuiitic  i>oiiuli.  HUr  te  »plft  off,  with 
formation  of  proparj;yl  alcohol,  llio  con^titiiiion  of  which  is  indicainl 
by  this  motbfld  of  rornDition,  nnd  nUoby  its  pro|iortici.  Tlie  presence 
of  t)i«  Krutip  ■CII  ia  shown  hy  tliu  rorniutiuii  of  metallic  dniTativos, 
and  Liuic  it  is  a  [>nniary  alcolml  i»  pruv-*^  Uy  the  fnet  Uial  on  oxida- 
tion il  yields  i^ropio/ic  add^  CllsC'COOII.  iiii  acid  containing  tho 
sani(>  ntitnber  of  tarboii  atoms. 

Pr^)pn^g;l  alcohol  ia  a  UiiLiid  of  aijreeable  odour,  aoluble  in  initsr, 
auci  btiilinp  at  I14'-n3'  ;  iu  speciflo  frnirity  at  31'  is  0-H8.  lU 
m«t«liig  dcriTAtives  are  expkeiTe. 


KOHOBABIG   inrSATTTRATSD   ACIDS. 


L   ACIDB  OF  THE  OLEIC  8EEIES,  CdH.b  _  ,0,. 

139.  The  acida  of  the  oleic  Beries  may  be  obtained  from  the 
Batnrated  acids  C„H^O,  by  the  general  methods  for  converting 
saturated  into  unsaturated  compounds. 

1.  Substitution  of  one  hydrogen  atom  in  the  alkyl-group  of  a 
saturated  acid  by  a  halogen  atom,  and  subsequent  abstraction  of 
haloid  acid  by  heating  with  alcoholic  potash. 

2.  Removal  of  the  elements  of  water  from  the  monohydroxy- 
acids: 

CH,.CHOH.CH,COOH  -  H.0  =  CH,CH:CH.COOH. 

^HydrozjT butyric  add  Crotoiilc  acid 

The  acids  of  this  series  can  also  be  prepared  from  unsaturated 
compounds  by 
*^.  Oxidation  of  the  unsaturated  alcohols  and  aldehydes. 

4.  The  action  of  potassium  cyanide  on  unsaturated  halogen 
compounds,  such  as  allyl  iodide,  and  hydrolysis  of  the  resulting 
nitrile. 


VomenolatUTe. 

140.  The  majority  of  the  acids  of  the  oleic  series  are  named 
after  the  substances  from  which  they  were  first  obtained,  but  a  few 
of  the  middle  members  have  names  indicating  the  number  of 
carbon  atoms  in  the  molecule.  The  first  member,  CH, :  CH  •  COOH, 
is  called  acrylic  acid;  others  are  C,n,0,  crolonic  acid,  CgH,0, 
angelic  and  tiglic  acidsy  C„H„0,  undecyUmc  acid,  C„H„0,  oleic 
acid,  C^H„0,  erudc  add,  etc. 

i6i 


15*  ORGANIC  CHEMSSTRY. 

It  miglit  tm  &ntici|>a(«d  thKt  in  tbi»  case  ttui  splfttlDg  off  or  luUold 
Acid  itlso  takes  place  oa  indicnled  in  tbo  Becond  raetliod,  with  tbe  pfo- 
duolioa  of  two  double  boiiila  -. 


«r 


CH..0C1,.CH,  -  SHCl  =  CH,=C=CH,, 


Cn.CHBrCnBr.OU,  -  SHBr  =  CII.=CHCH=On.. 


EiperiencQ  has  nhown  iIikI  this  I'a  not  the  case.  The  formuln  of  tbe 
r«inltiii(;  prului^i  mny  be  deierminod,  for  example,  bf  a  study  of  ita 
tiroiDini:  nJdiuon-products,  and  idw  ffom  Lho  refictioas  chiir&ctcmlic 
of  ootnpoundB  contaioin^  the  groap  sCH  (sec  below). 

Some  of  the  livdrtinarboiis  [irepared  by  the  foregoing  methods 
exhibit  a  jiecuHur  WImviour  towurdx  an  nniiuoiiiftpal  eolation  of 
eiiproiia  chl«rtd(i  or  of  »  silver  ealL,  which  aflordst  u  ready  means  of 
rocogniziDg  them.  Bj  replacement  of  hydrogen,  thej  yield 
m^taUii!:  (lerivativpR,  inaiiluhle  in  th«>  nmmonia^al  Rolution  ur  in 
wut^r,  whii^h  M-jMinite  out  &&  a  vnlnminouB  pretMpitHte.  Thfoe 
compDund.s  unt  explonive,  the  copper  yellow  or  red,  and  the  ulvvr 
white.  Acctylcnt  yioids  tlieao  tnetiiJIic  compoundii,  and  of  ibi 
bighvr  hoinulogttiM,  tliosu  di^rivt^d  from  the  dihslogcii  oomponnds 
of  the  Aldehydes  nUo  give  thorn.  Their  method  of  formAtlon 
thows  that  Ihene  homolojfuon  contniii  the  groap  sCH: 

C.H^,,-CH,0HO  — C«U^^».C'U,t;H{;i,  —  O.H,. ,  .cscn. 

From  this  it  may  hn  concludeil  that  th«  group  ^CII  ntutt  Ao 
fmrnt  in  the  hifdrontrhonn  wkif-h  yield  metailii'  dttrtvativtt;  it  ia 
the  hyilrogen  of  thU  group  which  in  replmted  by  metala.  In 
support  of  this  \iow  ie  the  fact  that  only  the  dichloru-deriratiTes 
of  the  rnvthylketonoa  (110)  Oiin  b«  trtuiafonncd  into  hydrocarbonaJ 
yielding  metallic  compoiinde: 

C»H^,,U0.CU,~^C\U.„,,CC1..CH,"CH,,.,.0=CU: 

C,H,.CO-C,H,  — C,0^.CC1,.CH,.CH,  — CV1,C'=CCU.. 

Da«4  nac  jitM  iiMtaiUe 
■IrriTiUrm. 

The  isomeric  hydrooarh^ns  containinif  two  donblo   bonds  (134) 
are  also  incapable  of  fomiing  metallic  pumponnda. 

The  hydrucarbouB  are  readily  prepared  in  tbo  free  stale  from 
their  matiJUo  derivatives  by  tht-  lurtion  of  dilute  bydrocliloric  sicid.^ 
Thi>  affords  a  mvaus  of  isohitiu^  the  momben  of  the  acrii 


HYDROCARBONS  tVtTH  TRlPie  BONm. 


•53 


•  O^Hy,.,,  which  yield  sucli  dorivativeii,  frum    luixtureH,  and   of 
nblftining  them  in  ttK>  puro  state. 

The  hydntcarboiis  of  this  eerioe  can  add  on  four  liulogon  atoma 
or  two  molecule)!  of  a  haloid  acid.     In  prcMD«o  of  mercury  salUQ 
they  can  take  up  water,  fonaing  iildohTdos  or  ketones: 

CH=CH  +  H,0  =  cn,.CHO. 

OH,-C=CII  H-  II.O  =  cn.oo.cH,. 

Id  this  reaction,  mercury  ccmpounds  are  first  formed  by  addi- 
tion: thus,  wheu  nlljlono,  C^H^,  \»  paseed  into  a  solution  of 
mercuric  chloride,  IlgClj,  &  prt?cipitate  of  the  compoeitiou 
3HgC],3HgO-:2C,H,  is  first  formed,  and  is  coorerted  into  acetone 
by  the  action  of  hydrochloric  acid. 

The  hydrocarbona  of  the  acetylene  series  also  posMSS  the  power 
'  fft  yielding  condeneation-prodnctt;.  Thin  eometimes  takes  place 
between  three  molecules;  thus,  acetylene,  C,H,,  eondensea 
Wnseue,  f'|,H„;  dimetliylacetyleny,  C,Hj.  to  liexamethylheuzetie, 
(',,11^.  etc.  The  action  of  heat  on  acetylene,  and  of  sulphuric 
acid  on  ita  homologuce.  effects  this  transformation. 

A  remarkable  reaction,  resulting  iu  a  change  in  tlie  [xiaition  ol 

I  the  triple  bond,  takes  place  when  the  hydrocarbons  of  the  serieaH 
C,H^^,  containing  llio  group  sCH  arc  lioatod  to  a  high  tempera- 


C,nj-C-H,.C=CH  is  converted  into  C,n^-C=C.Cir,. 


I'mp]  IkCMf  loDO 


Klliylms  thylftpBrjItni* 


It  is  probable  that  in  thia  reaction  uii  addition- product  h  fir 
formed  at  one  part  of  the  molecule,  followed  by  a  splitting  off  from 

•unnther  part.  Thitt  tho  diaplucement  of  the  triple  linking  doo8 
take  ptaee  in  thn  exaiuph*  givfti  abuTe,  is  proved  by  the  fact  that 
mlthongh  pmpylscetylene  yiolds  metallic  deriratirea,  the  xubctance 
^■obtuiuud  by  hiatiiig  it  with  alcoholic  potoah  does  not,  but  is  mn- 
^^-wtivd  by  uxiduliuii  iutu  jirupionic  .%ud  acetic  acida  Thi«  dctcr- 
minca  the  position  of  the  triple  boud,  since,  for  rcuaons  aimilor  to 

ItIiiMe  which  apply  tfi  thu  dotiUle  bond  (139),  the  inrlHUi  chain  is 
fanikcn  by  oxidiiiitm  iit  the  ptiiiit  nrcupiod  by  thu  multiple  hnnd. 
^bo  sabstance  obtained  must  therefore  have  the  fonnula  girea 
above,  and  hu  othylmethyUcutylcno. 


»54 


ORGANIC  CHEMISTRY. 


Acetylene,  i\Ry 

133.  Acetylene  u  a  ixdnurlvM  gua  of  disAgraoftbb  odour,  U 
Bomowhnt  itolnbic  in  WAter,  and  condcnics  at  18°  and  83  atmos* 
ph<>n*H  to  a  li((ttit]  bniUiig  at  —  82>4".  It  nm  he  syiitheinized  Trom 
itii  elementa  l>y  meniiii  of  im  electric;  atc,  i)(>tu'iM>n  riirbon  jmles  in 
an  iLtnioiiph«re  of  hydrogen,  a  »maiXi  quantity  of  metliHne,  and 
a  traco  of  ethane,  bping  eimultancou&ly  formed.  Ite  prcsenre  cno 
be  dpt(!ctcd  by  tnctuna  of  iin  ammoniucul  eolDtion  of  cuprous 
chloridts  which  yields  a  red  prtjcipitatc  of  copper  acetylene  even 
wlifii  tnipos  of  Bcotyl*?no  «ro  mixed  with  other  gases.  vVet'tylono 
is  iiIbo  obtained  as  a  product  of  the  incomplete  coitibii»tinn  of  ttiauy 
orgatiir  fliihuUnreB.  It  is  prepared  on  the  large  gcale  bj  the  action 
of  water  on  calriiim  rarbide,  or  calrium  aretylene,  CaC,: 

CaC,  4-  2n,0  ^  CalOIl),  +  (!,n,. 

The  reaction  Jb  somewhat  violent,  and  is  attended  with  evolnlion 
of  coiisidtTable  liwil.  Cahnum  carbide  is  prepared  by  heating 
citrhoii  witli  tjuieklimf,  CaO,  in  au  vIcuLrie  furuaoe.  The  caleium 
liberated  by  the  action  of  the  earbon  on  the  qnieklimo  enters  into 
combination  with  the  exeejw  of  carbon,  under  the  inflncnce  of  the 
hiph  tempemture,  and  formn  euleium  narbide,  which  is  white  when 
perfectly  pure,  but  haft  UKuallr  a  dark  reddish-brown  colour,  due 
to  the  prcHcneo  of  small  quantities  of  iron. 

Acetylene  oan  ho  prepnrrcl  iit  »  inodemtG  out  by  tliui  meihod,  and 
Aliem|its  have  been  miwli;  u>  uao  it  Tor  liglitin^  piiriinscs,  asn  stream 
of  ih«  g(U(,  pn»ii<ii  (broiigli  n  fine  o|wnirig,  liiirtiswirh  nn  liiionsely 
luniincti.t  flitmc.  Tp  to  the  present,  thc^icatlcmpishaii'cbt.-cn  nttendrd 
by  ililli'Ciillii^,  jtartly  owitif*  (o  ihe  eoHl  of  production,  bill  more  in  tlic 
nature  of  nccijlciie  ilaolf.  U  forn»  explosive  copper  aceiylene  vritti 
tbu  coppi-r  of  tho  )i;ft.i-11tllii)tH;  a  mixture  nitb  air  exploilra  with 
extreme  violence,  xiid  lit  inutb  mora  dangerous  than  a  mixtura  of 
ordinary  cualgiis  iind  air.  T)it«  is  due  lo  Die  Tiiet  thai  miieli  )ieat 
ia  taken  ui}in  tin?  forn]»Lmnofncet]rli:nc.  tiiiscooipuaud  buing&tronfly 
enduthcrmic  ("  Inorganic  ChemiBtry,"  97;.  In  adtlition  lo  Oiis,  the 
limiiH  or  explosion  are  much  wider  lb.in  fir  any  other  gM.  an  pxpio- 
■ire  miituro  teing  rormed  with  nir  by  iho  admixture  of  S-82f  of 
acelyletie,  while  iu  tbe  ca«c  of  ooul-f(iM  tbc  liniiU  are  only  S-ftSX. 
Tbe  TetocKy  of  prupagution  or  combustion  is  able  much  greater  in  the 
case  of  aootylooe,  aud  thie  augncnts  ooasidcrably  lb«  fococ  of  the 
explosion. 


HYDROCARBONS   WITH   TtVO  DOUBLE  BONDS.  IS5 

Acptylenc  preparutl  from  ciilciuiu  carbide  nan)i>limefl  contains 
small  qiiaiiiilies  of  8ulphiiret[c<l  hydrogen  aud  phoaphnrellcd  hTclro- 
gen,  to  wliich  it  owed  its  disagreoivblc  amell.  iLcnn  bo  Tmud  from  tlin 
fonner  l>j  a  ooliitiuii  of  cnuKllu  nikiili,  and  from  t\w  liitk-r  by  »  siAu- 
lioa  of  corrosivfl  siitilinintu  tu  hyilrocliloric  ncii)  Tlic  removal  of 
pfaoopborettcd  hydrogen  is  of  upecial  iiii]ioi-lniic«,  siuoo  iia  preseooe 
Dfty  Iflnd  lo  the  BponiBOe^ua  igiiitiou  of  llie  gaa. 

By  tlio  dim^t  hydrof;euHlioti  of  acHttyleric  in  presence  of  Pndiicwil 
nlcknl  <BS  mid  ISi),  Sibaticr  itnd  Scvderkit!:  havoobtniiied  liquid  iiiln- 
lun»  uf  hydixwiirbi}[is  which  cna  Iw  luitdv  lo  corrwpund  ddicr  vritb 
Ann'riuiii  ur  CtiicHdiiiii  put I'lli.'um  by  varying  thv  noiidtiiciiiii  of  the 
eiperimani.  To  account  for  the  formotian  of  pclrolpum.  Ilioy  aAsiimo 
tlial  there  are  in  the  interior  of  the  earth  free  alhali-moialit  and 
mMnllio  onrhide-t,  which  in  cnulaot  with  naier  leive  riftw  t«  oiistuntt  of 
hydrogen  And  hydrocarbons.  Thi!s»  gnsot  encoiinler  flnoly-dlvMwl 
nickel,  cubftlt.  or  iron,  and  thiin  yield  Ih^i  mixturt*  of  hydrocnrboDa 
constJIutind:  nntund  ]>utroI«iini  (Ml, 

B.     IITDROI.'ARBOXS   WITH   TWO   IiOtlHI.K   »OXI>.S. 

lU.  HydrocnrbouB  with  Ivro  diinble  bonds  huve  been  comparn* 
lively  Ittila  inrMii^^AU'd.  Attmr.  ix  oblniried  fmm  iTibromopropane, 
CniBr-CHBrC'lIiUr,  by  mmoviil  of  IIBr  by  mcAnn  of  pocafih,  and 
substiqiieiit  tivnlmmit  of  Iho  dibfoin(>-cum]Kiiiud  thuH  Formed  mtb 
zioo-dLiat,  which  remorcs  the  two  remaJntiig  bromine  aloniA  (IM) : 

CU.Br-CHBr.CH.Br-*  OH.iCBrC'H.Br  -•  CH,:C:On^ 
ThbruriiuproiMiiie  [iHiramupropjleaB  A-ltana 

Apmttttition  fotlowA  from  t4)is  methml  of  propnration.  It  is  a 
flloari— gaB.  Hnd  nnlihothe  iaomoric  allyleno,  CncCsCII,  drwn  not 
yield  m«billiodoriVHtiv0B  (132). 

DiaHyl.  CH,:rH-('n,-Cn,.Cn:rn,,  i*  obtained  by  th(!  ncium 
of  sodium  uiwn  a%;  ^ffije,  cn,;CH-Cn,I  (lU),  from  whieh  It 
follows  that  it  hus  thu  couatilution  iodlcjitnl  by  ihc  above  formula. 

A  hydroc'arlHiii  of  ihU  Kuriasuf  thooruiiuil  im[)i>rtaiiao  id  ittoprettit, 
Ctlli.  It  is  obtiiined  by  the  dry  distillation  of  caoutchour'.  ;iiid  ts  k 
liquid  boiling  at  .17'.  By  the  union  of  two  or  more  mnlcciiliM.  It 
pastes  iciio  lerpeiieH,  CuIIit.  CnH,,,  ate  It  is  coiivcrted  by  cou- 
«niiTiilw1  bydrochlurie  ncld  into  a.  gnUstwico  Klroni^Iy  rwembiing 
oftoatchouc,  pcrhnps  idunticnl  irilb  it.     I«opr(-iiG  is  pron-d  to  hnve  ibo 

eonstittition  p|j*>-C.OH=Cn,.  by  the  addition  of  9HBr,  whieh 
yielda  a  dibromide.  ^g|  >  CBr— CTI,— CH.Br.  idenUc»l  with  (hat  ob- 
taltwd  from  dimelhytallene.  pJJ' >  C=C=CH,.  j^ 


STTBSTITUTIOH-PKODUCTS    OF    THI    TTHSATTIIIATED 
HTDEOCAEBOHS. 


i^ 


'  I.    tTHBATtTKATZD  HALOOEW  COWOinrM. 

1S5.  Since  the  satmmtcd  hydrocarbons  thomBclvcs  do  not 
posscM  any  wHent  clmnuitertstirR,  thu  propprtiM  of  tfactr  com- 
ponndn  i1<>{ir>ni]  upon  the  luituro  of  tho  Rubstitiiting  elements  or 
groiipR.  TTithprto  we  have  tmly  <'onHiderp»l  ntunpoiinds  whnee 
properties  are  dtio  to  the  pivBitiHTc  In  tho  raoIecniR  of  b  fiinsle 
group,  hrdroxyl,  curboxyl,  u  multiple  furhoii  bnwl,  etc.  We  liave 
now  to  deflcribo  subetanoofi  containing  more  than  one  cKAnict«ri«iio 
gronp  in  thd  molomlp. 

When  thpBo  groups  are  proiioiit  Kimultaneonely  in  tho  same 
molecule,  thej  genemllj'  exemRe  a  mndifying  influence  upon  one 
another.  The  extent  of  this  influence  va-rios  ponHidemhly,  lu  will 
be  neen  from  a  (ronHiduralion  of  thu  different  i-lusses  of  niisaturut«tl 
halogen  compounds. 

Halogen  derivatiVM  of  tho  typo  C„lI,n_,X  aro  obt&inod  by  the 
luldicion  of  h&logon  to  the  hjdroearhonB  C.H,^,  and  snbsequont- 
ftbBtraction  of  one  moleoiile  of  haloid  acid: 


CH,=Cn,  -1-  Br,  =  CH,Bi^CH,Br. 
C'I(,Br— CII.Br  -  HUr  =  CH,=CIIBr. 

F.lhyliinn  liroriilili*  Vlnjl  lirnmli* 

They  ore  also  formed  by  removal  of  one  moleciilf  of  haloid  aci4 
from  eompounda  containing  two  tmlogen  utums  liukeil  to  Uia  eune 
carbon  atom : 


CH,.Cn,-CHC],  -  HCl  s=  cn,.rH=cuoL 

TiopylidKia  chloride  ■'Oiloroi'ropr'i^n* 

C^.0C1,.CII,  -  HCl  =  cir^cci— CH^ 

CnlorowtflnnR  0<C»U>rapmiirlFne 


196 


UNSATURATED  HALOGEN  COMPOUNDS. 


>$7 


'he  methoiU  hy  which  these  compontuls  arc  obtjiined  indicftte 
that  the  halogen  atom  in  thorn  in  Ihtkod  to  »  nirbon  iitom  hurtng 

\%  donhle  l>on<1.  Their  propertios  differ  widuly  from  those  oC  com- 
potinda,  atich  ae  tho  alkyl  halidos,  in  which  th«  hulogon  atom  is 
linked  to  u  curb'Ou  utoin  hnving  only  single  bonds;  and  tliix  rule  ii 

hgeuerally  ap]>li«nble  to  conipoands  of  this  kind.  Tho  halogpn 
atom  of  the  alky]  hali(l>e«  is  «Rpemlly  united  for  inking  part  in 
dotiblo  decompositions,  being  nipliirpabl e  by  hyilroxyl,  an  ulkoxyl- 
group,  nn  ocid-rosidue,  the  umido-groap,  etc 

Thii  aptititdafor  ddubU  decompoaiHon  m  itlmoul  wholly  icantinjf 
in  emapovHiU  wAow  haiogeit  alow  is  Utihed  la  a  carbon  atom  with  a 
donbta  homt  Alkalis  do  not  convert  them  into  alcohole,  nor 
slkoxideH  into  ethers;  bnt  iiivarinbly,  when  a  reactiori  does  taka 
plaoe,  M  haloid  iMiid  is  split  ofT,  with  formation  of  hydrocarbons 
of  the  eorios  (-'„II,„ .,. 

iAn  isomer  of  «-  and  fi'chioropropgltn-e,  which  have  be«i 
Inferred  to  iiborc,  is  t-alled  nfltfl  rhioride.  Tlie  liidogGii  atom  in 
this  t'Oinpouiid  tuko«  part  in  double  dei-umpoxitioutt  a^  euelly  as 
tluit  in  Bii  alkyl  cliloridi?.  Allyl  chlorido  is  obtained  by  the  action 
of  phosphunu  pentachloride  upon  allyl  alcohol,  which  can  be 
]»re)ttred  by  a  nivthod  to  be  dcecrilied  later  (168).  This  alcohol 
yiohU  H-pro])yI  alcohr.1  by  addition  of  hydrogen,  and  its  hydroxyl- 
Ifroiip  nniRt  therefore  bo  at  tlie  end  of  the  carbon  chuiu.  Hence, 
UiD  halogen  atom  in  allyl  ehloride  must  also  Iks  uttarhed  to 
the  end  of  the  chain.  bJuwj  it  takes  the  placu  of  the  hydroxyl- 
grnup.  t'ivL'U  tliL-  cunslitutionx  uf  a-  and  /^-propylcuu  chloride, 
wliich  ar«  dedueed  from  that  of  propionuldetiydv  and  acetone,  tlio 
sUyl  lutUdes  can  only  liaro  the  constitutional  formula 


CH.=CU.OH,X. 


re  the  halogen  atom  is  Httauhed  to  a  Hin^dy-linked  carbon  atom, 
d    retains  it»  iiominl  ohamcUfr  in  stpite  of  the  prc«i»noe  of  a 
double  bond  in  tho  moleoiile. 

Tliis  dejiendence  of  thp  rharaeter  of  a  halogen  atom  on  its 
position  in  the  molecule  of  an  tuiBatii rated  compound  afTnrds  a 
eanA  of  determining  nhcthcr  it  \s  attached  to  a  t>ing1y-l inked  or 
-linked  carbon  atom,  by  ascertaining  whether  it  does  or 
does  not  possess  the  power  t^  take  ]iitrt  in  double  decompositions, 
lite  following  arc  examples  of  individnnl  momlicrs  of  the  BeriB& 


158 


ORGANIC  CHEWSTKY. 


Vint/J  ehloride  CH,:  CHC'l  is  a  ga^,  vint/t  bromidt  CH,:  CHBr  «1 
liquid  ot  ethereal  ixlour.  Both  these  compouodt  putfmartM'l 
rewlily. 

Atttil  cMorule,  allifl  hromide,  and  aUgl  iodide,  boil  rvtpexixi^j  \ 
Mb  AG"',  TO",  nuU  103"%  TKl-v  are  often  tued  in  syntbeMt  for  tbej 
mtrodactiou  of  an  oi»»tarBt«d  pronp  into  a  conpoond.    Theyj 

I  bftTO  ft  chaimctcristic  odour  reaembling  that  of  maataid. 

Tlie  proparggl  compouiuU,  CUsC-CH.X.  mar  be  nwntiaaed] 

[as  a  trpe  of  the  seriM  C.U^  ^,X.  Tbeir  constitatiDn  ia  mfenedl 
from  thi'  fai't  that  tbej  yield  mi^uUic  di-riTaiivM,  aiioviii;  tbat'j 
they  contaiu   the   group  C=U,  «iid   aUu  becMiie  tfaair  habctaj 

I  atom  M  oapftU*  of  taking  port  iu  doaUe  d«o(MBp<MitMBt.  sad  tg  j 
therefore  attached  to  a  sinf^ly-Unked  «arboD  atom.  TbcT  aia{ 
obtained  horn  propargrl  alcohol  ( L38 1  bT  the  action  of  pho^bontt ' 
pentabalide,  and  are  litjaids  ponesnng  a  pungent  amelL 


The  ooaiponai  CBBr :  C,  tromo9oet$tidaK,  whidi  »  aMaaed  If 
Xir  to  cootaiQ  a  d:TKkmi  earbon  aiom,  can  beotatalBed  froat  aeM|1iaai 
brontdo,  ClIBr:  CHBr,  b;  traatiaeat  with  aloohoBo  potwh.     It  li  a] 
gaa,  taking  fire  spootaMMuljr  in  Uw  air:  iu  acliMtoa  la  aleokol 
pfto«|Aore«o«ot,  oKiDs  to  slow  ondaboo,  and  tte  gee  HmU  hm  aa 
odoar  Tttj  snilar  to  iliai  ot  pboq>boni&. 


tL  raurvKAns  alooroul 


136.  Thv  hfdiwiyl-groQp  of  the  nnaattmtad  <)f^1wh 
taaMD^y-fiakad  or  duabtj'linked  catboa 


CH,:  CHCH,OU. 


CH,:  CH-OE. 

To;  lev  I— fnaadf  of  iLe  l^pe  of  ■naj\  aledMil  aae  kiiom.     la 

tha  mmjoAf  af  caaa  ia  wiath  tlidr  fnnaatiap  mi^  he  expected, 

|«hcir  iaeaen  an  obtataad.    That,  vben  vaker  u  ahatiaeled  fremi 

gI;tMl,  C^OH-CH,0H.  theic  raaalts.  not  winfi  mktitt,  CHOH. 

CH,  I 

kataaiMwT.aaflald«hi^    I      u  ^ 

Wbn   /MffMMprapjteM,  CH,-CBr:CH,.  m    fctatif    with 

r.tlMtektonaedaot  ^,rdniTTproprlim,CH,Ci(OHK('H,, 

that  tlM  iwaagiii  atatane.  Ca,-CO-Cilj     It  hat  htm  ^enendlr 

thai  in  oaan  in  vhk^  a  graa|aig  of  Urn  atoaa  b  the 


UNSATURATF.D  ALCOHOLS. 


»59 


llbnn  — CU:C(OH) —  would  Iw  DBtnr&llj  expectpd,  a  traiisforma- 
Itiou  into  — OH, -CO —  occars.  Hubstanoee  containing  hydrosyl 
'  itlachod  to  n  doiiE>ly-linke(l  carbon  atom  are  therefore  uuniable, 

tliiit  in,  they  have  a  tendency  to  Iwcome  transfonnw]  into  laomers. 

It  uill  1»6  fieen  later.  bpwKVBr.  tliut  cunipounda  do  exist  iu  which 
|thc  group  — CH :  C((4—  is  -tafth  {240). 

Ttie  followos  ooinpoundfl  elUier  contain  byJroxjrl  attached  to  a 
doubly -lin):4barbon  ntom,  or  are  related  to  subttaitoefi  of  this  type. 

Vinyl  ulciiftoi,  CH('.  C'HOII,  so  called  because  it  oontAinti  the 
tini/t-gf'>a]\  CK>:C)!— ,  )trMtiflhly  oceum  m  ordliiiLry  ctljyl  (Vlhur 
irbicb  has  filood  for  isoniu  time,  and  tbcrutiy  uudcrgoiio  partial  oxida- 
tion. When  Buoh  elher  la  sliakou  up  with  an  alkaline  solution  of  a 
mercary  salt,  a  precipitate  of  the  oompeaition  U^iCliOirilli  is 
formed,  wbioli  on  treatment  with  a  haloid  acid  yields  viiiyl-eom- 
pouiid&. 

A  viiiyl-dorlTative  of  great  pliyslologlcal  fniportanco,  called  neu-  _ 

Hue,  m  formed  in  tlie  decay  of  dcah,  and  in  other  fcrmcutation-  ip^*^* 

prooewie«.     Its  constitution  is  (CHi),Ncy„  *       ',  as  indionted  by  the 


followioir  bymhe«ia.  When  trimothytnmiuo  reacts  with  ethjlono  bro- 
mide, a  sub«tituit>d  aiumoiiiiiTn  hromido   is  obtained  with   the  for* 

SiQla  (CH.).N<y^^'■'^'*•^^    HBr  is  abstracted    from    the   group 

— CHi-CH.Kr  tiy  tbe  nclinn  of  moist  silver  oxide,  the  bromine  atom 
attached  to  nitrogvii  beip);  re|>]nuRd  by  bydrosyl  at  the  aauie  time. 
Asnb»t)in(ie  of  the  conKUintioii  indimlMl  alxtvo  is  obtained  from  it, 
and  is  in  oil  rcapL-uta  identical  with  ucuriiie. 


^^^. 


AUyl  AleohoX  ClI,:  CIICII.OU. 

1S7.  Many  tniiMturitted  aU-ohols  containing  hydroxyl  attached 
to  B  £mfi;lT'linkC4l  carbon  atom  are  known.  The  most  important 
of  those  is  nllyl  aloAal,  obtained  by  a  metliod  to  he  deserihed  later 
(168).  It«  confititution  follows  from  that  uf  the  (chlorine  dpHviitive 
tormod  by  the  a^-tion  oX  phusphonis  pcittachloridc.  (135).  hh  well 
u  from  that  of  the  products  obtaiucd  by  oxidation,  by  which  ullj! 
Icohol  is  converted  firet  into  an  aldehyde,  acroh'in,  and  tbon  into 
rylicaeid: 

CH,:cn-cn,on  — cu.:(iio<J{  — cn,:Cii(;oon. 


AUri«k<dwi' 


Aorrlic  «old 


ORGMHK  CHEMISTHY. 

Alljl  aloohol  mart  tbeivfore  cuntain  tbe  gronp  — CH,On,  which 
if  cksracCvrutit;  of  {jrimury  alcobc^. 

Alljl  alcohol  u  It  liquid  with  su  irritatiiij:  odour,  solidifying  at 
—  iM>',  and  boiliug  iit  &i>-5%  «ml  \a  miectMu  witti  wak-r  in  all 
proportionfi.  lu  apccific  (rriTity  ol  i>'  in  0-872.  It  lorma  addi- 
tiou-productH  with  the  halogenn  and  with^ilrogeti,  jrielding  with 
tli«  lalWr  n>propyl  alcohol. 

Many  »tli«r ootupounds  containing  theallyl-groiACnsiCH-CHi — , 
are  known.  Of  lli«sfl  ailsl  autphid*  ((-'It,:CII'Cl7,S,  the  pritictpAl 
cnnMittiviit  of  oil  of  gaHic,  in»>'  Iw  niDiiiiniiml.  It  i«  nynrh^ticall; ; 
obtalnod  hy  the  action  of  potaitsltim  i(ul|)hkk',  K|8.  oii  allyl  iodi<l«. 

Wu  havA  seen  that  the  influence  of  the  double  bond  in  the 
anHuturatcd  halogen  oompoundii  and  alcohols  is  very  prooounced 
wbun  it  ia  Hituuted  in  the  immediate  ndghbonrbood  of  halogen  or 
bydroxyl.  but  tlmt  otbcrwiiKi  it  in  much  lusts  murki-d.  Tbo  rule  is 
tbat  when  two  grouft  are  ailuated  in  immetUatt  prozimit^  to  om 
another  in  the  same  tti^lfcuUy  each  group  ex0r£iw$  tt  $ironff  infiwnc* 
upon  th*  pri>}?erliti  of  th«  oth*r. 

Fropargyl  Alcohol,  CUsC -011,00. 

1S8,  Prnpargyl  ak'/inA  voutaiaa  a  trifile  Wuil,  Aod  is  propar^d  In 
(b.i  following  w«y.  CH,BrdlRrCll,Rr.  iriltromhydrln  iiaS).  is 
OOUTortud  by  troatmonl  with  caitattc  potuh  into  l!lI,:CBr-(!H,Br. 
Tbeii  (ntalod  witb  poUMium  jii-«late  and  tbon  MipoiiiUcd,  lliis  yields 
OUi  :CBr-CH,UII,  since  only  tho  terminal  Itr-ntam  Is  «apAt>1e  of 
taking  part  in  u  doublo  decamposiUon  (ISS).  Wlicu  ibU  alcaliol  is 
again  brought  into  ooolnct  witb  cnojiiic  potash.  HUr  is  split  off,  with 
fonnatfoii  uf  prMparicjl  mIcuIkiI,  the  cnnMiitniion  of  which  U  indicated 
by  Ihl.t  m^'tlKid  of  funnntion,  iin<l  itUoby  its  prnporlio*.  The  pn^Mnca 
of  ihv  t^ruup  ■  I'll  is  shuwn  by  tbu  formation  of  mnlallic  derlTalivea. 
and  thill  it  is  a  pntnary  nicolial  In  proved  by  the  fitet  tbat  on  oxida- 
tion il  yioldti  propioiic  adrl,  GHsO-COOn,  an  acid  containing  tb« 
■ano  ntiober  of  carbon  ninms. 

Pn>[iHryyl  iilcohol  in  a  lii|iiiil  of  ajcfo^ablo  odour,  snlnbla  ia  watar. 
and  bdilJDp  \i  iir~lia'  ;  lU  itpooiflc  gravity  at  31*  ta  0'&68.  Iia 
metaliio  doriTativea  an  ozplusiTv. 


KONOBASIG  TTHSATTTRATED  ACISB. 


I.   AOn»  OF  THE  OLEIC  8EEIS8,  C„H,n  -  *0,. 

139.  The  acids  of  the  oleic  serieB  may  be  obtained  from  the 
Batnrated  acida  CnH^O,  by  the  general  methods  for  converting 
satorated  into  unsaturated  compounds. 

1.  Substitution  of  one  hydrogen  atom  in  the  alkyl-group  of  a 
saturated  acid  by  a  halogen  atom,  and  subsequent  abstraction  of 
haloid  acid  by  heating  with  alcoholic  potash. 

3.  Removal  of  the  elements  of  water  from  the  monohydrozy- 
acids; 

CH,.CHOH.CH,.COOH  -  H,0  =  CH,.CH:CH.COOH. 

^-HydroxjrbutjrJc  acid  Orolcnilc  add 

The  acids  of  this  series  can  also  be  prepared  from  unsaturated 
compounds  by 
^^,  Oxidation  of  the  unsaturated  alcohols  and  aldehydes. 

4.  The  action  of  potaaeium  cyanide  on  unsaturated  halogen 
compounds,  such  as  allyl  iodide,  and  hydrolysis  of  the  resulting 
nitrile. 


Vomenolatura. 

140.  The  majority  of  the  acids  of  the  oleic  series  are  named 
after  the  substances  from  which  they  were  first  obtained,  bnt  a  few 
of  the  middle  members  have  names  indicating  the  number  of 
carbon  atoms  in  the  molecule.  The  first  member,  CH, :  CH  ■  COOII, 
is  called  acrylic  acid;  others  are  CjH,0,  crotonic  acid,  CjHgO, 
attgelic  and  tiglic  acids,  C„H^O,  undecylenic  acid,  C„H„0,  oleic 
acid,  C„H„0,  erndc  add,  etc. 

i6i 


Itl2 


OKCASIC  CHEMISTRY. 


OeD«»l  Fropertlet. 

141.  Like  all  coniponnds  coutaiiiiDg  a  doiiblo  bond,  the  Acids 
of  thia  aerieit  iwsseett  the  jiower  of  forming  additioii-iiroJRCte. 
Thej"  ar»  "gtrouger"  acida  than  the  corresponding  fatty  acids 
coDtuiuing  the  eaniu  Dumber  of  carbon  atoms  in  the  molecule; 
tliu^  the  value  of  the  coastant  K  (93)  for  propioaic  acid  C,H,0, 
is  IJ-W13-I,  for  ucrylif  at-id  C.II.O,  0-0058,  for  biUyftc  acid 
C,H,0,  1I.0(JI4»,  for  t-rotunic  atiid  C,ll,0,  «. 00^1)4,  etc.  The 
double  bond  uausefl  the  acidti  of  the  oloic  series  to  he  much  more 
readily  attwkdd  by  oxidiziug-agcnts  than  thotto  of  the  fatty  sphcs 
(129).  The  former  arc  converted  by  energetic  oxidation  into  two 
eattiratcd  ncidis  but  whoa  the  reaction  i^  restnunod  by  u^ng  a 
dilute  eolntion  of  potAsginm  permangnnato,  a  dihydrosy-noid  con- 
taining the  gronp  — CHOI  I  ■  C  H  OH—  i«  formed  as  an  intorraediata 
product,  and  on  farther  nsidation  iaHplit  up  at  the  bond  Ijctwcea 
tliese  two  carbon  atomH  (129).  Thin  aiTords  a  meant«  of  ileter- 
miiiing  the  position  of  the  double  bond  in  the  mnlcciilo.  A 
breaking-iip  of  the  molecule  with  formation  of  sHturatGd  fatty  acids 
alco  lakes  pUce  when  an  unutuntcd  acid  is  fueed  inth  caustic 
potash  with  ncoeee  of  air: 


C„H,„.,CH:  CH-COOH 
KO  H 
KO  U 

O 


OlH" 

=  C.H„  .  jCIOK  +  CH^COOH. 
0^ 


This  reaction  was  at  one  time  often  employe>I  to  determine  the 
poiiition  of  the  double  bond.  imd«r  the  imprp»;ion  that  the  docoiu- 
aition  «f  the  molecule  vfft«  effected  at  the  point  where  this  bond 
ras  situated  in  the  first  innunee.  It  U  now  known  that  under 
the  inflHoiico  of  fusMMl  ciuiKtic  pnta«h,  or  oven  by  lK>iliug  with  a 
solution  of  i?iuistic  Rodttj  the  position  of  the  double  bond  b«oome<i 
shifted  nejirer  to  that  of  the  carboiyl -gronp.  Fusion  with  caustic 
]iotavli  is  therefore  not  iipplicablo  to  the  detormiDatioD  of  the 
])Ofiition  of  double  botidd. 


AoryUc  Aoid,  CH,:C!1C00U. 

14S.  Acrylic  acid  U  obtained  by  removal  of  HI  from  /3-iodo- 
propionic  acid,  CH,I-CU,COOH.     It  is  a  tiqnid  with  a  pungent 


^aOS  OF  THE  OLEIC  SERIES. 


163 


I 


odour,  boiling  »t  140°,  und  U  roducod  by  nnaceni  KydrogeD  to 
propionic  acid. 

Aeidt  with  th«  formnlft  C.II^O,. 

143.  Sereral  ncids  with  tlin  forniulii  (',(1^0,  are  known.  In 
accordance  with  tho  thooi^'  of  cunatitutioa,  tho  following  hfo 
poseiblo: 

1.  CH,:CH-CH,-C0OH;     2.  CH,CH:UH.COOH; 

Four  Isomeric  acida  with  the  fonmuU  0,11^0,  are  itctually  knovn. 

An  acid  of  the  constitution  indicated  in  formula  1,  vinylacetic 
mar  be  obtaint'd  Kyn thoticully  (23S).     U«  formutiou  by  tho 

ou  of  potusiiuin  cyaiiidu  uxx  iiUyl  iodide,  uud  eupoullicutiou  of 
tho  nitrile  tbu«  formed,  might  be  expected: 

cn,:  cn.oii.i — en,:  en  -cn.cx — en,:  on. on,,  coon. 

Antnally,  howcTcr,  an  acid  hariiig  the  formala  3  is  obtained,  tolid 
crotoDic  acid,  which  melts  at  71^  and  bnils  at  180°;  for  it  is  con- 
tertcd  by  careful  oxidation  with  pormnngnnate  into  oxalic  acid, 

Hooc— coon. 

IsocTOlonic  acid,  a  liquid  boiling  at  172°,  has  also  tho  con- 
atitntion  %,  because,  on  the  one  band,  like  solid  crotoBic  acid  it 
can  be  reduced  to  71-butyrio  acid,  showing  that  it  too  contains  a 
normal  carbon  chain ;  on  the  othor,  it  ia  conrerted  by  oarcftil 
oxidation  into  oxalic  acid.  Ordinary  constitutional  formulie  ur« 
incapable,  thoreroro,  of  aocountitig  for  tho  isoniorigm  of  these 
adds.     We  shall  see  later  (170)  bow  it  is  explained. 

An  acid  with  the  formula  3  is  obtained  by  the  abstraction  of 
Br  from  bromo-iHobutyric  iicid,  and  is  called  laethacrylic  acid : 

^{{•>0Br.CO0Il  —  ^"'^CCOOH. 

01«Ic  Acid.  C,,U^O,. 

144-  Oleic  acid  in  obtainw!  by  the  saponiflcntion  of  oili  and 
fats  (91>.     In  onlur  lo  separate  it  from  the  uitnrated  fittty 


l«4 


ORCANtC  CHEMaTRY. 


addir  aUaric  aoil  piiJmilit-  actda,  which  uv  Mt  hM  U  the  umft 
time,  OM  is  made  of  its  le«d  ntt,  whivh  iii  rcsilily  mlabW  in  Hhvr, 
in  contndUtiactioii  to  thow  of  tlip  Rataraipd  fattr  acids.  The 
okrc  wc\A  !■  libenittfil  from  the  lend  olcate  b;  treatment  with  scidg. 

At  Mniitinrr  U.-nippnitiirM,  oleic  acul  is  a  licjnid  melting  at  14~. 
vithout  odour  and  of  itu  oily  lutaro.  It  oxidizes  reiwlilj  i»  the 
air,  and  cnoaot  bo  diitilM  without  decompotitiou  under  ordiuarj 
prMmros. 

01«Tc  acid  contwns  a  normal  carbon  chain,  Riace  it  is  coDTorted 
hj  rvdnccion  into  alearii;  ackl, 

KRAPrr  baa  proved  the  normal  sirnctore  of  alearic  ncidbyconvert- 
ing  It  atAp  t)}'  ittvp  ttilo  adda  coiilaiiiinK  a  smaller  tminlMr  of  cartioa 
atoms.  Ilk  niullind  U  aa  follom.  Wbni  jtubitiiCLM  to  dry  dtstillattoit 
111  a  vacuum,  barium  >l«ame  aud  barium  acetate  yield  a  kctooc^ 
0,»II..-CUCH,: 

0.,H,.|60bbaMrbaO!Q0-CH.  -•  C  :.H,,OOCH,. 

Dirtun  •(««nto  Barium  mixUM       KftmsirlmirlbjlkrtoDo 

On  oxidation,  thia  ketone  fialdii  acetic  aoid  and  fun  acid  of  tbt 
focmola  CiiIImOi.  This  nliows  Ibat  iu  th«  ketoa«  tb«re  must  be  a 
OHrgroup  next  to  tho  cartionyl- group,  ko  that  It  box  thit  formula 
0>*llit-C'IIi-CO-Cl],,  iiiaco  onl}-  in  tbii  ciuso  could  oxidation  pnxlucs 
as  aoid  with  seventeen  oarlion  atoms.  Tliis  acid,  C'l.ilt.O,.  {margarie 
acid,)  b  ooiivtrted  in  the  name  way  into  a  ketone,  OifUii-CO-CHii 
which  OD  oxidation  yieldH  an  noid  C-«ni,Ot.  The  formula  of 
narsnrio  acid  must  tlivroforu  bo  Citlli -CIli-COOU.  and  that  of 
•tearic  a«i(I.  C..1!..CH,.CII,  COOU.  Tim  aoid  C.ili..O.,  paimitie 
add,  i«  in  ila  tuni  oonverted  into  a  ketone,  etc,  and  the  prooeu 
OODtiauod  until  nn  aeli]  Ik  obtained,  ixiprie  aoid.  Ci.Hi.O..  which 
has  been  proved  hj  Hjntbcsis  i83>6.  1)  to  oontain  a  uarmtil  carbon 
olialn. 

Tho  presence  of  a  double  bond  in  oleic  acid  is  proved  by  its 
fomiiiifc  an  addition -prod  net  with  hiomin»>,  «nd  by  it«  power  of 
nsdnring  nn  alkaliuf  pcrmnngnnato  wlntion  (183).  The  double 
bond  Ik  Rituati>d  at  tho  middle  of  the  molecule,  tho  constitution 
of  olttic  Moid  being 

CU,.{Cn,),.CH;CH-(0H,),.CO0H. 


•ha>tBa 


j4aDS  OF  7HH  OlMiC  ANO  PROFIOUC  St-KlES. 


1*5 


Tbis  oonstitntion  tu  iuferrecl  from  tbe  prodaoU  of  carofal  oxido- 
tiun,  which  yieHA  pehrnjviiic  aciii,  C,H„-COOH,  and  asBlaie  ncid, 
UOOC-(CIIj,.COOH. 

Oleic  acid  reacts  in  a  rery  remarkable  manner  with  nitrons 
Hcid,  eveu  when  it  te  brought  in  contact  with  »  mere  trace  of  this 
milwtNiice.  The  reaction  is  best  carried  out  by  p&seiiig  Iho  red 
gw,  which  is  a  mixture  of  NO,  and  NO,  obtained  by  heating 
iir!ier)ic  triosiile  with  iiitriv  acid,  into  oletc  acid,  thu  same  ofT«ct 
imu^  pruduc-vtl  hy  the  adilitioii  of  uitric  acid  of  8[>i?.cillc  gntritv 
1<3S.  The  oleTc  acid  becomes  solid  aft«r  »  time,  being  converted 
into  an  isomer,  elaidic  and.  Tliia  reaction  U  called  the  "elaidic 
transformation/'  It  is  also  undergone  by  other  iLcida  of  tliis 
seri«B;  thus,  erueie  acid,  C^n„0,,  U  converted  by  u  trace  of 
uitroiiB  acid  into  braasiiUc  acid. 

Khidic  ueid  has  the  «8ino  Ktruclura)  formula  as  olaic  acid,  the 
doTibli*  bond  occupying  an  idcuticul  position  in  the  molecule  of 
«uch,  itinoe  i-ach  ncid  rt^odily  forms  a  bromine  addition- product, 
which,  by  removal  of  ^llUr,  yields  the  same  acid  in  both  caoM, 
G,,H„0, ,  stmroiie  ncid: 

f;..IU0,-C..II,Br,O.-C„II,0,. 

nirto  Mill  ^Iklillr     BiMinln*  bldlilnD-    Ri«*roll0  aold 

Tlieae  two  acide  yiold  the  same  ketoatoaric  acid  by  the  addition 
of  one  molecule  of  water,  which  is  ofTcctod  by  ths  action  of  con- 
centrated sulphuric  ncid.  Tbo  isomerism  of  oleic  acid  and  elaidic 
acid  is  tlier^forp,  like  that  of  enicic  ncid  and  brassidic  acid, 
analogous  to  the  iitomeriKm  of  the  two  crotonio  acids  (143). 


n.  AoiDi  or  TSB  paorioLic  sebies,  Caii,„.,o,. 

14&.  The  acids  of  the  propiolic  series  hare  one  triple  bond, 
or  two  double  bonds,  in  the  molerulo.  Tbc  Qrst-nnmod  iiro  forrnod 
by  the  action  of  rarbon  dioxide  upon  the  sodium  uompounds  of 
the  acetylene  hydrocarbons : 

CHsCNa  +  CO.  =  CUsC-OOONa. 

Bodliun  [inlpluUle 

The  aridi)  thus  formed  hnv(>  »  Iriptp  bnnd  attached  to  the  rr*carhon 
atom.     Acids  of  this   uaturt-  arc  ven'   easily  split   up  into  uu 


1^ 


i66  ORGMNrC  CHF.MISTRY. 

acetylene  hydrocawboo  and  CO,,  especidlly  on  hoatltig  their  silver 
wlt<. 

A  general  method  for  the  prepftnition  of  acide  with  triple  bone 
consists  in  the  addition  of  two  bromine  atoms  to  acids  containini 
a  double  bond,  and  siib»oqiieat  abstraction  of  SIIBr: 

CH,CH:CH.COOH  — CH,CHBr.CHBrCOOH  — 
—  Cll.CiC.COOII. 

^  TBtroUe  add 

Snbfltances  containing  a  triple  bond  pOB«esa  tlie  j>roperty  of 
adding  on  water  under  the  influence  of  ooncentmtcd  sulphuric 
aaid,  with  formation  u(  kotonut : 

_o=c .  — cn.co— . 

Thne,  stcjirolic  a«id,  uientionvd  above,  is  convorted  into  a  koto* 
stoarh  acid  of  the  formula 

C,H„-C0-CE,-(OH,KCOOH, 

wliich  IB  tninaforrned  into  the  corresponding  uiimo  by  treatment 
with  lij'droxjlttmiuv: 

C,U„CCn,.(CH,),COOH. 

iiou 

Under  the  inflnenoo  of  ooncentratw)  sulphuria  aoid,  this  oxime 
undergouH  the  Bkrkmann  traiiBfumiutiuu  (112),  amoug  the 
products  being  the  aiibstitutt^d  acid  amide 

C.II„.GO 

NU<CII,),COOH, 

which  is  proved  to  hare  thi«  formula  by  its  docompoeitioQ  into 
polargonic  acid,  C',II„C001I,  nnd  tho  9-aminononoTo  acid, 
N II,- (CH,),.C00n,  when  acted  upon  by  fnmhig  hydrochloric  acid. 
This  is  a  conlirmation  of  tho  constitution  Bbove  indicated  for  oleTo 
acid  and  ehildic  acid,  since  they  can  be  converted  into  staarolio 
acid  in  the  wity  already  described. 


ACIDS   mTM  TIVO  DOUBLE  BONDS.  C„H„_,0,.  167 

Acidi  with  Two  Doable  Bonds,  C„H,b_.U,. 

146.  Very  few  of  these  are  koown.  Among  them  may  be  men- 
tioned «or6^  acid,  CtHtOi,  which  is  crystalline,  and  melts  at  134-6'. 
It  occurs  in  the  unripe  benies  of  the  mountain-ash,  and  has  the  con- 
stitution CH,-CH:OH-CH:CH-COOH,  as  is  proved  by  its  synthesis, 
the  condensation  of  malonic  acid  with  crotonaldehyde  under  the  in- 
flaence  of  pyridiue  as  a  condensing-agent: 

CH..CH:CH.C|?-r-jT-  „  ^  COO  H 


^       ....    iO  +  H.C<,~"=CH..CH:CH.CH:CH.COOH+CO. 
Crotoiuhlabydfl  ' ■ ,COO|H 


HklOOlOMid  +H.0. 

Isomeric  with  stearolic  acid  is  linoletc  acid,  CiiHi,0, ,  obtained  by 
the  saponifloatiou  of  linseed  oil.  When  carefully  oxidized  with  potaa- 
sinm  permangaDate  it  is  converted  into  a  tetrabydroxyBtearic  acid, 
CiiHiiOt(OH)«,  which  proves  that  it  oontaias  two  double  bonds  in  the 
molecole. 


55^ 


TVSATtrftATED   ALSEHTDES   AMU   KSTOHSS. 


L   raiATCBATES  ALBEHTDU. 

147.  Tbc  first  member  of  the  tinsstarstcd  «ldebyd«s  if  aeroltin, 
CB,:  CH-CIfO.  It  is  obtAJocd  br  n-morftl  of  vatcr  from 
gWcerol,  a  procesa  best  effected  hj  beatiog  with  poiiuaiutn 
mnhydnMulpluite,  K^.O,,  or  witb  boric  acid.  It  u  a  oolourle« 
Ijqnid,  tmling  »t  52 . 4",  nnd  has  an  crtTemely  powerfol,  penptmt- 
ing  odonr,  to  which  it  owes  it«  name  (actr,  sharp,  and  oleum, 
oQ).  The  disagreeable,  pongent  smttll  produced  when  a  tallow 
candle  or  art  oil-Ump  is  L-xttuguidlifd  is  due  to  the  fonaittion 
of  acroluiu.  On  a-ductiou,  it  >-iekU  aU;I  alcohol,  from  which  it 
regenented  bjr  oxidation.  It  ia  oonverted  into  acrylic  acid  by 
farther  oxidation. 

It  bus  the  propurtiea  peculiar  to  aldehjdee — the  lusoeptibilttT 

to  reduction  and  oxidation,  reaiaiBcation  in  preaeace  of  aUcalis, 

and  the  power  of  forming  polymerisation-prodnctB.    It  jiosevaaetf 

this  last  prop«rtj  in  nich  a  marked  dogrw  that  jt  DsuallT  becomes 

[wfaoUj  conTert«d  into  a  polymvr  in  the  course  of  a  few  dav«  or 

even  buUTB,  probablv  tirirlc-r  iho  catjilnic  iDfluonoe  uf  tnkoes  of 

impuritiM.     The  preseace  of  ttie  double  liond  in  acroluin  modifies 

[to  some  extent  it«  aldebydic  properties.     This  ts  exhibited  in  its 

[tbehaTiour  towardH  ammoniu,  with  which  it  does  not  combine  in 

Lthe  same  way  as  acetaJdehyde  {"LIS),  but  in  aocordanoe  witb  the 

rfotlowiDg  oqmition: 


aC\H,0  +  NU,  =  C,H,NO  +  H.O. 


[AcTolein-ammouia  is  an  amorphous,  btwic  snbstanra,  is  eoliible  i 
[ water,  and  in  its  appearance  and  behaviour  towanlti  water  bears 
resemblance  to  glue. 
Acrolein  does  not  unite  with  one  molecule  of  an  aeid  sulphite, 
witb  two,  yielding  a  compound  from  which  acrolein  itacif 

i68 


UNSATURATED  ALDEHYDES  AND  KETONES. 


i6^ 


cannot  ngnin  bo  obtainod  by  the  action  of  acids,  wliieli  only  split 
nS  one  molciciile  of  the  acid  snipliite.     It  mnet  therefore  he  mp-' 
posed  that  the  other  inoleciile  of  acid  sulphite  b»e  attached  itself 
at  the  double  bond. 

Crotoniadehyde,  Cn,-CH:CHCnO. 

I4S.  fVntmiaiilebtide   resului  on   tbe  s)>1ltltn£  off  of  irater  front 

aldol,  CH>-UBlOH[-^U|n|  -Cq  (l»).»heD  it  is  heated  to  HO'.    It  iaa 

liquid  boiling  nt  lOl'lOS',  aod  u  conrcrKid  by  oxidntlaD  vriih  silvor 
oiide  lau>  solid  crotonic  acid,  a  ro»cti(>ii  wliitli  [irovi»  It  to  havo  iba 
constltntton  indionted  by  t)i«  above  formula. 

l^rvparyiftatdehffde,    ORsC-C^J^,  can  be  obtaiiivd  from  a,<irolein- 

nvctal  by  tbo  addition  of  two  bromine  aioms,  stid  &ub««quoal  reutovnt 
of  3UBr,  by  means  of  oniutic  potiuili,  from  tlio  addition-iiroduul  tbus 
fonnod  : 

CH,:CUC(,^^„^j^  —  f'H.Br-C11Br-C,oo^g^j^  — 
A«r«l«I[)ac«Uil  Di^iViDCMMiniMiiail 

— CllaCc]*,,  „  ,  . 

Tlic  tatter  acetal  Is  enuTerted  by  nnrmiiiK   with  dUnte  sniphurlo. 
■old  Into  Iho  (H>rTV«ponding  aldehyde,  nhicb  linji  tlie  Sianio  irritnting.1 
action  on  tbi-  mucous  niumliiruiiiti  u»  iicrolctii. 

The  bolinviour  ut  prupaixyialdtliytle  wicb  alkaliK   is   rviuurksbla 
It  is  split  ap  into  ncetylcao  nod  formic  acid: 

a  tTKBATUEATED  EETOKfiS. 

141.  Amoos  tb«se  muy  be  mciitioiini  mr.i'li/1  oridf,  CtllKO.  aiuj 
pkoTxmt.  CiHiiO.  Goib  iirc  oblaitit-il  by  rhc-  condrimation  of  acctoaa, 
wilb  etiminnllon  of  nrxter.  Mosityl  oxido  ta  a  colourl^M  liquid,  B.  P. 
130*  aud  Bp.  icr.  0-844  at  23',  is  in-tolable  in  water,  and  pnssesam  & 
strong  peppermint -likn  odour.  It  Is  ro«Agnix<>d  jik  an  iioaitt iintt«<l < 
ketone  im  ai?coiini  (if  ila  yielding;  an  oilme.  itiid  Wn\g  I'.HjMibte  of  forni- 
iag  addilioii'pKMliicta.  Ita  kctniiic  cb-irnetf*!*  is  fiirHinr  injtuifefjied  by 
its  failiiiE  to  yield  an  acid  cootaitung  the  same  numboi'  of  ciirtwa 


i^i 


COlCFOUirSS  CONTAnriKO    MOBE  THAH    0H£ 
SUfiSIITUTING-GBOUP. 


I.    BALOOBir   DEirVATITXS  OF   MITRAIfl. 

160.  It  ia  p(««iiili'  to  rci)]!!^!"  all  four  hyilrogen  ubnme  in 
methiine,  in  succesHivp  etuj^a,  hj  the  dlrvt^t  action  uf  chluriiiu  or 
bromino  in  prcaenco  of  eunlight.  lodiuo  does  not  react  with 
me'hnuc.  or  with  its  bomolognes.  wliilo  the  notion  of  flnorinB  is 
very  vuorgetic,  effooting  complete  fiabgtitittion. 

In  practice,  bowever,  tliia  in  not  the  motliud  udupteil  for  the 
pn-puration  of  tlie  coiniiouiida  CII,X, .  ClIX,,  or  CX,.  They  aro 
obtjiiued  from  the  trilialogcn  dcrivativoa,  readily  propart-d  by 
another  method,  vliich  yield  tetrachloromcthane  or  tetrahromo- 
mcthane  without  any  clij1i<?uttj,  on  i!hlonnB.tioTi  or  hmmtnutinTi, 
and  ar*i  convnrtpd  on  ri-duction  into  dihiilojfon  metlmiip.  On 
accdant  of  thoir  importtnt  thorapeuticjit  properties,  the  oonipounds 
OilX,  are  proparud  on  the  lurgc  nctklo. 

Chloroform.  CHCI,. 

151.  Chloroform  ia  obtained  by  dietilHng  alcohol  with  bleach- 
inp-powdpf.  la  thia  roaction.  in  which  otidation  and  chlorination 
go  on  together,  it  is  siipposMl  that  alduhyde  is  llret  prodiicod  liy 
oxidation  of  the  alcohol,  and  Is  then  couvertod  into  triehloro- 
aiUehjfde,  or  dioral,  CCl^-CHO.  Thia  giibBtanco  is  convorted  bj 
basee,  in  this  caec  hr  the  slaked  lime  present  in  the  bleaching- 
powder,  into  chloroform  and  formic  acid  (204). 

Chloroform  io  a  liquid  builUig  st  61°,  and  solidifying  at  —  TO". 
Ita  8[>e«ifl«  gravity  at  15"  is  1.408;  it  ia  only  very  idighlly  soluWe 
In  water,  and  possee^g  a  characturiMtlc  othoreal  odour  and  street 
taste.  Ita  prolonged  inhalation  prodncoa  unconsciotisneaa.  whence 
it  derirca  its  ralae  as  an  anKsthulic  iu  surgical  operations. 


Cklirirfunii 
sndtr  tW 


hat  «n«aUe  ■Wti.  ami  imeampoem 
of  lj«)a  aad  air,  yiMimg  rMnriiw,  hjdio- 
flSTeUoride,  OOCV    TUt  deeaBipo«iti(m 
to  »  fn»  otwt  fav  eke  additiaa  of  Ijt  of 
tiw  dilonllBrai  m  bottlv  at  Bon^ctisic 


The  pn—imliTii  actioa  of  deobol  prebUjr  dtpends  apon 
ibi  enwl>wWiwi  wHh  tb«  deeoBpod^Mft-praJBHi  of  tW  rhloro- 
{ofB.  tku  prarentiftf  tbeir  «iarc>BtBg  s  eatalTtie  accelenting 
iataMM  «a  Um  daeaayorinea.  The  btkcc*  *(«m  <*t  ohloro- 
ferm  lake  part  in  dcaUe  itBomptmOtmt;  ihatr  uMam  echoxule 
jiekl*  the  tth^  etfer  at  octbolbniiic  acki: 


CHlfcl,  +  iSaj  -OC^  =  CH(OC,HJy  +  3XaCL 


• 


Fonnk  acid  can  be  vbUizMd  from  «Uorofonii  br  warming  it 
with  iHaU  aUtalu,  orthafoMie  a<Tid  being  probably  formed  aa  u 
ntensMlute  ptndnct.  aUbMiglt  tb«  hcter  baa  not  been  iaolated. 
Wben  cbloroforai  ia  treated  vith  an  atjoaooa  aolDtion  of  caottie 
fotaA  <4(H>,  rarboD  moDoiide  is  rrolTed;  it  b  aantned  thiit 
ddorametbirleae,  CC'I, ,  ia  foiraed  aa  an  intenudiale  prodact  in 
tfaia  reaction. 

Wfaen  eUorofonn  it  warmed  wilii  aleohoUc  ammonw  KoA 
fluHk  potaah,  itt  tbrea  dilorine  auoa  are  replaced  by  nitngeD, 
with  prod  Dction  of  potaninDi  cjranjde.  The  formation  of 
inoicrilea  from  clilomfnnn,  alcobolic  potaah,  and  prinunr  anitiMf, 
hea  been  alread;  mentioaed  (M). 

CUanpicrim.  CdJIOt .  u  obtaiscd  bean  cbloroform  bjr  replac?. 
nau  «f  lbs  bydrogeo  atom  hf  «  nitro-crmp  by  titaUMnt  wiib  con- 
eriWift^  Bilric  acid.  The  Mnuiitatioii  of  chkmfilertti  is  inilrmted 
%gr  ila  jiMiog  netbjlamine  on  ndootioii.  It  u  a  liqaid  witb  au 
aali'ftly  pungeol  odotrr.  and  fo  ttuallr  obtahwd  by  tbe  distillaUon 
a(  pitrie  a«id  with  bl«achiRg-powd«r.  to  which  node  of  [>repanU»oa  it 
ovMtta  namn 

MeOil/ltm  cJUor<d«,  CUJCi, ,  ia  obtained  fn>Bi  ch)or«fona  by  redoc- 


HALOCEH  OF.Rti'Anyf.S  OF  METH/INE. 


173 


ti«n  vith  ziii«  •nd  hjdrMhIorle  acid  fn  itloaholic  •olntlon.  It  is  a 
liqukl^  boiling  nt  40*,  nad  having  a  spectflc  grarity  of  l'S37. 

THrtwhlorometAan*,  or  earbon  tttrachloridt^  CCi.,  prwiueet!  by 
(be  nctioQ  of  chlorini;  on  cliJoroforED  or  carbon  dLsiilpliide,  is  also  a 
liquid,  and  boils  at  711°.  When  heated  wUh  ojccea  of  water  nt  2B0'  it 
jiclds  nci  «[id  COi,  Its  sprcitlc  jtravitj  Ja  IflfiS  m  20°.  It  will  be 
nolkod  that  th&«e  higlior  ch!r>rinct  «iilM!itiiliflii-pnHltM^tx  \\Kvti  high 
specific  KTavities.  The  bromjno  and  Jodiiio  campouadii  hnro  consid- 
emblf  higher  densities  than  th«  oorrespondint;  oUloriiio  oompeunds, 

Sroirw/iirm.  CITBri ,  is  ohtnintvi  analogoasly  to  chloraform.  Il 
mfitm  at  7-H\  bniU  at.  151*,  and  has  a  sp&ojfio  gravit;  of  2'1)04  at  15*. 
It  finds  th<;rup(!utic  applicHtiuu. 


Iodoform,  CHI,. 

IBS.  Iodoform  U  a  mbetonco  of  great  importanci!,  and  is 
obfMDcd  from  alcohol  hy  tho  action  of  pntni^Rium  carbonate  and 
iodino.  The  intcrmcdiulp  product,  Cl,CHO,  aiialogoiu  to 
chloral,  has  not  been  iiirilatei:!. 

Iodoform  ctii  also  b«  prepar«d  hy  the  plectrolysU  of  a  eolation 
CORtaining  Oft  g.  of  palaasium  iodide,  id  g.  of  sodium  rjirl>oiiiiti\  and 
80  oc.  of  alcohol,  in  oaoh  400  ce.,  the  t^mpernttire  being  kept  at  CO*  u> 
OA*.  lodlitfl  In  ftct  fme  at  the  anode,  so  that  the  nicoliol,  KtOOi,  and 
I,  n«ceMary  to  the  formation  nf  iodoform,  are  all  pn-Jinnt  in  tlie 
miitnro.  About  SOitoftliu  jKiiasnlum  imlidv  in  by  this  method  caa< 
T«rt4>d  into  iodoform,  wliih*  thv  rfni»ludi*r  nf  thu  iodinti  is  finally  ob- 
Utined  aa  poi«ftsium  iodnlo.  Tho  foramlioii  of  iodfuto  can  be  aroidcd 
to  a  great  extent  hy  sQrroiiadiiig  tbo  eathude,  at  which  uaiuttic  potatli 
is  fonii«Hl,  wUb  imrohiiienti  nhioh  prevenia  the  potasb  from  eomiiig 
in  ooDtaet  vlth  the  iodine  got  free  nt  the  anode. 

Iodoform  is  a  nolid,  and  crystallizfis  in  ypllow  hoxagonnl  plates. 

has  a  pecntiar  NklTrnn-likc  odour,  stiblinieB  very  readily,  amd 
melt*  at  11  S°. 

ThpsSR  fhanictcristic  proptirtics  of  ioiloforra  nmlip  Its  rorumtion 
aa  importAut  tetit  for  alcohol,  attboiigh  it  must  be  remembered 
that  aldehyde,  acetono,  and  sovcntl  otlier  !a>iib8tanc«e  eimilarlr  ri«ld 
iodoform.  Sii1>8tnDco6  cmitnining  the  gmiip  ('I[,-C  linked  to 
OTTgeu  answer  to  tlie  iottmfiirm  tent.  It  ia  carried  out  by  adding 
ioHbe  to  the  li<[uid  tn  be  tes(«d,  nittl  then  catistic  potash,  dro])  by 
drop,  until  th«  colour  of  tho  todiDu  raniahnR.     If  a  largo  quauUty 


>74 


ORGANIC  CNSMiSTRY. 


of  alpohol  h  present,  a  yellow  pwoipitnto  is  at  ono«  fonncMl ;  if  only 
traoeit,  snme  tinio  huR  to  elfi|)i>e  before  tLis  tnkt>8  jiliicc.  Tito 
r«ft(-.tioii  iH  xuflidptitly  <lplicate  to  s)inw  trnceK  of  »Irohol  iti  well* 
iratr^r  nrid  th  in -water,  after  it  h&s  hccn  coureiilrated  a«i  mnrh  u» 
poambin  by  repttatct]  distillation,  tbe  iirst  fmctiDn  in  «ach  case 
being  coUcPtod, 

lodofonn  is  used  in  surgery  as  ad  ivDtiscptie.  It  is  wftrtby  of 
notice  (bat  it  docs  not  directly  kill  the  bacteria,  but  th&t  lu  action  on 
the  mioro-orgaDUina  depends  upon  n  pmrioui  doeompoaition  brought 
alMiiil,  under  the  inlliiuiicv  of  tho  hunt  of  the  body,  bj  h  fermcntutire 
a«tioD  of  the  niAttftr  sopnrntod  fri>m  Iho  wound. 

Meihijlent:  lodiile,  C1T,I,.  u  obminod  by  Ihp  reduction  of 
iodoform  with  hydrioilic^  acid,  phosphorus  being  added  to  regen- 
erate III  (29).     It  iH  a  liquid  of  remarkably  lii^h  specific  gravity. 


U.  HAIMBH  DEBITA.TIVE8  OF  THE  flOHOLOOITSS  OF  KSTHAHZ. 

15S>  It  is  cTident  that  among  these  deriratircd  Duoierom 
lera  are  jKyssible.  For  example,  replaoemeiit  by  chlorine  of 
ree  hydrogeu  atoms  in  uormal  pyntaim  may  taki-  plaw  in  a 
number  of  different  ■ways;  a  methyl-group  may  bu  eonvertoil  into 
GOl,,  two  chloriiie  atoms  may  replace  the  hydrogou  of  onu 
muthyleiie -group,  white  the  third  rcplac-c^  another  hydrogen  ntniti 
in  tlic-  molecule,  or  ull  three  c-hlorine  atomtt  may  uttaob  thomselvt^ 
to  different  carbon  atoms:  aiid  eo  ou. 

The  methods  for  tlie  preparation  of  many  of  the  halogen  t-om- 
poandK  included  uuiUt  tliiiti  Invading  havi'  ulruiidy  bcL^i  mcntioiittl, 
tho  Kompounds  0^11^,^  ,-CUX,  and  CVII,^  ,  ,-CX,-C,H„_ ,  being 
obtftined  by  tho  action  of  phoephorus  pentahalide  on  sldchydfs 
and  ketones  reepectively  (106).  (.'oropcninda  containing  two 
halogen  atomit  attached  to  two  adjoining  carhon  atoms  are  obtained 
by  the  addition  of  lialogetia  to  the  hydrocarbons  Cn'It  '  those  with 
four  halogen  atomii,  two  of  which  are  directly  attucht-d  to  ci*t:h  of 
two  adjoining  carboy  atomx,  aro  produced  by  the  addition  of  liiUo- 
gen  to  bvdrocarbong  containing  a  triple  bond;  while  compounde 
of  the  typo  (.■,il,^,,riIX.ClI.\.C,H„.CHX.CHX.C™H„., 
arc  obtained  hy  luldition  of  halogen  to  tho  hydroearbona  CqH^.^^ 
contjiining  two  double  boudit;  etc. 


'HALOGEN  bERfi^ATtt^ES  OF  HOMOtOGVBS  OF  MFTHAHE.     I75 


A  general  method  for  the  preparation  of  compoimda  rich  id 

lalogi'ii  from  llie  saturated  liydrot-'arboiiH  ie  tlie  exubange  of  one 

iriirogeu  atom  for  lialogeu,  removal  «f  lialoid  aoiJ  by  meanii  of 

alooholic   potafih.    tialogeiiaiiou   of   tK«  hydrocarbon   CbH,„  thtw 

oliiained,  renioval  of  !L\.  n-nL-Wftl  lialogenation  of  tho  product, 

and  su  uu. 


CH,CH.-C£J,Cn.Cl-HCi 


CH,;Cn,-f  2CI- 

Et£]rleoe 


-.ciici.cnci  ■  -nci  - 

SiliylnDr  iFtmctilortitn 


-.0HSCU  +  4C1-. 
'CnCI:CCl.+  2Cl-. 

TrtchlDTocthylEDo 


-*  Cn01,-CCL  -  IICI  -  CCl,:  CCI  +  2C1 


-  CCL-COl.. 


^^  A  geueral  method  for  the  preparation  of  compounds  rich  iu 
I  bromine  w»e  dincovered  by  VicroK  Mkver,  and  conflists  in  tho 
direct  notion  of  bromine  on  tJie  hydrociirbons  of  tlie  series  C„li,„  , , 
in  presence  of  a  small  (jimulity  of  anhyiiroiis  iron  bromide,  or 
lore  Finiply,  of  irou-wiro.  Under  llmso  eouditions,  the  aubettlu- 
»i  takes  pUce  very  ri^adily,  and  it  \\aA  been  aliown  that  each 
rixtn  atom  of  a  normal  chain  only  takes  up  one  bromine  atom. 
Phii8.  propane  j-ietils  tribioinliydrin,  ('il,Br-CHBr01I,Br, 
ii:o  ibc  prodtx^t  is  identical  with  the  addition -product  obtained 
tho  action  of  bromine  on  allyl  bromide,  CIT,;  CII*CH,Br. 
When  many  of  the  hydrogen  atoms  of  a  hydroearbon  C„H,„, , 
fcve  already  been  replac-ed  by  chlorine  or  bromine,  it  is  no  longer 
Blblo  to  aiihatiliile  Iiydrogm  by  the  direct  action  of  a  halogen. 
Chlorine  has  no  action  on  pentauhluroetliuuo,  for  example. 
tui'XKYn.iT  ha£,  however,  ahowu  thai  giib^titutton  readily  takci 
ICC  in  presence  of  a  *inaH  qiianlity  of  alnmhiiiira  chloride,  which 
i-I  eplita  off  haloid  aeid.  Jn  thia  wnv,  pentachloroethano  with 
alaniininui  chloride  yiehls  tntraehUroefhylene,  and  the  addition 
of  halogen  takes  place  at  tJie  double  bond  thus  formed,  the  prod- 
uct being  in  this  inKtunce  hexachloronthane. 

Nomenclature,  and  Indiriduat  Hembert. 

154.  Clompouuds  containing  a  halogen  attached  to  a  teniiinal 
rbou  atom  are  denoted  by  tlie  prefix  w,  if  to  other  carbon  atoms. 
a,   (i,    etc.      (:H,Br*t'H,'CII,Br    ie     Gwy'-dibromopropsne; 
,ISr'CHBr-CHj  i»  (aa-dibroraopropaue. 


176 


ORGANIC  CHEMISTRY. 


Only  a  few  of  the  numonmii  o-om pounds  nf  thin  gronp  wili  b« 
described. 

EihyUue  bromide  U  emplovod  for  syntheses,  and  as  a  solveut. 
It  is  ]>rRpar(Ht  by  It^iding  erbylenc  into  bromiui?  covered  ^ith  a 
layer  of  VKter  to  prevent  cvnporAtion.  thp  additiou  tukiug  pluc« 
very  readily.  Ethylene  bromide  i*  a  colourless  liquid  of  a^cwablu 
odmir,  Holidill'09  »t  H"^',  boils  at  131°,  and  has  n  specific  gruvitr  of 
Si8Sati6% 

EtAffUwcfibHidt.  ClltCI-CHiCI.  is  called  "Dutob  Liquid."  or  the 
"Oil'of  the  Dutch  Cheoiistfr,"  owitiK  tu  tli<  fxoi  tlint  il  wan  Qrst 
prejiared  at  the  end  of  ibe  eiKbteeiirlt  (century  by  four  Dutch  clieiiiists, 
DeIMAN,  BfNDT,  PaETS  van  TR008TWTK.  ftud  LAUWXitEXBonoH,  bj  the 
action  of  clilorini.'  it|M)ii  rthyiuiiu.  It  is  R  liquid  boiling  at  84-9%  and 
hfi»  n  spcoifi«  gravity  of  I  -93  at  0'. 

7'rtmfthifl(ini<  bromide.  CII,Br>CH,'CH,Hr,  bidi'-dibrontopro- 
paDe.  also  plHVKaii  imporcaut  part  in  synltiuh-eii,  and  in  obuined  by 
addition  of  HKr  to  allyl  bnimide.  CII,-f:H-CII,Bt.  prodiicfd 
from  lillvl  uU-ohoI.  This  incbhod  of  furniaiion  suggests  its  httriiig 
the  oonstitulion  OIf,CHBr-nr,Br.  whoa  it  would  be  identical 
with  the  addition-product  obtained  by  the  action  of  bromine  upon 
propylene,  Clli-t'II  :  CH^.  Sinoo  thiK  is  not  tin>  cam,  the  first 
roQittitiitioDal  formula  given  above  is  of  neceasity  asslj^cd  to  it. 
Trimcthylcne  bromide  is  a  litiiiid,  B.  P.  105%  ap.  gr.  1   ^74  at  17*. 


m.    FOtTHYORIC   ALC0K0L8 

165.  Wbun  more  tlmii  one  hydru^^i-n  utum  of  a  saturated 
liydrocorboii  ij.  replaced  by  liydroxyl.  it  is  tlieorctically  possible  to 
havo  mitre  thiin  one  hydroxyl-frronp  in  union  with  n  single  carbon 
stom.  or  tfl  have  eaeh  MtlacheiL  to  a  iiifr»rent  one  U  shoubl  be 
possible  to  obtain  rompouiuU  of  the  first  rlaBs  by  replneemem  of 
halogen  by  hydroxyl  in  the  halogen  conipminds  II  GUXj.  It  CX, , 
nnd  K-CX,'  IJ .  When  this  is  atteinpled.  for  instiinre  by  hrinfriuR 
IiitJof^n  compoimdh  of  ttiis  Ivpc  itilo  oonlftoi  with  silver  aoelatc. 
with  thointeution  of  stibsequeiUly  Bjipoiiifying  iho  compound  thus 

obtftiaed,  stAblc  noetatc*.  snnti  aa  (''Jii<()c'H'o'  ""^  '"'*«''  rendily 

Jormod.  Bat  on  saponiticHtion,  a  dihydric  alcohol'CHf(OH>,  k 
not  obtained  from  them,  iddebyde  resultinj;  inntead  by  the 
elimination  of  one  molecule  uf  witur.     When  ijompunudf)  of  the 


tT{M>  [tCCl,  ar(>  tTented  with  itodiiiin  uthoxide.  Kubsttnctt  witli  tbo 
gfuenil  formultt  UC'(OC,!ij),,  ciUled  ortho'tst^s,  are  obwiiied. 
Oil  Mipouilimtioii,  howevur,  II  C(OLI),  dout  not  result,  tho  oorra* 
epondini;  avid  being  formed  iiiKtoad,  thruiigh  loss  ttf  watvr.     Kthera 

iif  dih>-dfic  alcohols,  siicti  as  CH,-CII<Qj>*tt*  are  known,  and  are 

t        i 

called  aoftaU  (113.  'i).  The  decomposition  of  these  HobstancoB 
vields.  not  R'CH(0]I),.  but  an  aldehj'do.  It  follows  from  these 
consideratioiis  that  coinf/Oimtls  with  more  than  one  htjdTOxyUffroup 
aiinfheil  lo  the  aame  carbon  atom  are  )in«fable.  We  nhall  see  later 
that  it  in  poiutible  to  obtain  taivii  cumpnunds  iu  certain  ea«0)S  (204. 
233.  237.  and  266). 

Miiiiy  iMimpoii nils  arc  known  nontaininj  aorerul  liydroatyl- 
gruup^,  of  ^s'hicli  nut  tnort!  tlian  oiiv  in  attocbod  to  «a<:li  carbon 
atom.     Some  of  tbeao  are  described  below. 

1.  Glycol!  or  Sihydric  Alcohols. 

180.  The  glycols  are  obtainod  from  the  correstiondiag  hulogoa 
com])Oiuidii  analogously  to  tho  monohydrio  alcohols  (43): 

CH,Br  Cll,Cll,Br  +  'ilJ.O  =  CU^Ofl-ClI,  CH.OH  -f  2HBr. 

TrlniPibllFue  brwrnldo  TrliiiFilijrlPiirKlycvl 

The  pxcliaago  of  halugeu  fur  liydroxyl  chh  he  brought  aivmi  by 
traatDent  with  acetate  of  sllrornr  of  an  alkall-metal,  and  aa[>oiiifiai- 
tion  of  the  diacetate  thua  obtained.  It  caa  uIno  lie  eflotilod  by  boiling 
with  sodium  carbonxti-  Holutioii.  or  walrr  uiid  luad  oxidu. 

GlycoUof  tho  type  KCUOlIClIOll-R,  in  which  the  carlon 
■toin-  nttarhed  to  hydrosyl  are  in  direct  union  with  ou«  iniotber, 
are  fnrmod  from  olelines  either  through  tho  incdiuiii  of  thoir 
bromine  aildition-prodiicts,  or  by  the  direct  addition  of  two 
Oll-groiipfi  by  inctiii£  of  cturful  oxidation  with  jiotii^fltum  perniaH' 
ganate.  Iu  this  way  ethylene  yieldis  the  Bimpleel  dihydric  alcohol,' 
uik'd  gif/eoi : 

CH,:  Cli,  r  H.O  +  O  =  un.oii  CH.un. 

Abolher  raeltiod  for  llto  formation  of  glycoia  of  this  type  coneiata 
Id  lh«  reduction  or  kelones.  Tliis  may  be  eitlier  carriod  out  with  ko- 
dlnai  in  aquvoua  wlution,  or  Irallcr,  by  clootrolyai^.  Fur  Ihis  purpose, 
the  icetuu«  is  diuolved  in  dilute  sulphuric  scid :  on  pasitliig  m  citrrcnt 
through  t)iifi  fiolu(io[],  ih«  reductioo  takes  plaw  al  the  cnlhottc.  Thus, 
ooctune  yinkia  /liiuicone,  In  addttiou  to  isopropyl  aluohul.     All  tlie 


L 


178 


OROAMC  CHEMISTRY, 


I 


gljcota  ohiainccl  t>j'  this  luothod  ar»  disUni^isliad  by  the  iinitiv  pin»- 
oon«s.     Tlie  oonslitutiaa  o(  pjiucoae  U  indicsted  bj  this  xytitlu-Mx: 

CH.-COCH,      II      OH.-0(OH)CH. 

cn.oo.ou,     II    ciuc'toiiiou.' 

"Wlieii  dtsUilecl  with  ililtit«  aiilphiirio  noiit.  pinAcoTi«  iindrr^ioc^  n 
remariuble  [ntmiimlccular  trKiinfoniuiTiini  wliicli  uui;  be  cxi>lAiiteJ 
by  ajunming  that  n  bydroxyUgniup  chiuigca  pUoo  with  a  ntfftbyl- 

(CU.),0(Oin-C'^tl.— tCH.}.0.C^i()H^-H,O  =  iCH.).C.OO.CH,. 

The  Goiitlitattou  of  pinuvotin  mny  lie  dnluai^)  Ttvin  its  synthesis  hf 
X\w  Hirii'Mi  of  zine-ni«tliyi  on  tiie  cblnrSdu  itf  trImetliylMvtIc  nchl, 
(Cn.uCCOCI.  jinil  Id  otiiw  wiiy*. 

The  msjorilr  of  the  glyooln  are  colmirlt'sii,  viscous  liqaid.s  of 
Bvet-t  tast-e,  whence  the  fieriea  ilerivus  itd  uiiiiic.  Thuir  lioiliii;- 
points  unil  sjierific  graviUee  are  considcruWy  higher  than  llmite  of 
tlie  monohydric  aLcohola  coiitaiQiug  th<^  «nmc  namber  of  carboti 
stome.  '  Thus,  glycul  WJla  at  Hi7-a°,  ai\^  ethyl  alcohol  nt  78'; 
Rt  0^  tho  sjMtrilic  gravuy  nf  glycol  im  1  ■  138,  and  of  ethyl  alnohol 
0'80().  The  behaviour  of  thit  hydroxy! -group  in  glycol  and  in  the 
tnonohydric  alcohoU  is  jwrfeetly  tmalogoua;  exchange  of  Olt  for 
halogen,  the  foniiatioii  of  ethers,  ■ester*,  ami  alkoxidcs,  and,  in  tlie 
case  of  primary  glycols,  the  formation  of  alilohyties  and  adds,  may 
take  plattc  in  oonuection  wllh  ono  or  both  of  the  hydroxyl-gTou[». 
For  inetatioo,  tho  coniiiouncls  C'H,OI!  CHjCl,  qliffolchlarhtfdriu, 
CiI,OC,n,CII,OiI.  sh^i  momelhyldke,:  CII,dc,II,CiI,6c,n„ 
glffrot  d\dli\(hther,  otr. ,  aru  known.  The  glycols  possess,  however, 
one  property  (hit-  to  tli«  jiresciiet'  of  two  liydroxyl -groups,  the  power 
of  forming  auhyJridw,  The  lirst  member  of  tho  eerie*,  glycol, 
CH,OII-CH,OH,  docs  not  yield  an  anhydride  by  the  direot  olimi- 
oatiun  of  water,  but  a  compound  of  tli«  fwrmiila  <',H^0  is  obtained 
by  flmt  replacing  one  hyilrnsvl-group  by  CI  and  then  splitting  off 
UCl: 

Cil.Cl  CH,. 

I  -  UCl  = 

OH/ 

EUiyWui  oxida 


CM  OH 

Otjeol  ohlti  rliyilrl  a 


> 


CLYCEROL. 

This  coRiiioiiiid,  elhtflene  oxidt,  boilii  at  ]4~,  luiil  Is  therefore 
gaectfUi)  at  onJinarr  tvmporattirca:  it  roadily  takes  up  water,  form- 
ing glynoh  «p  hvdroi'hiorif!  arid,  forming  glyculclilorhytlrin.  To 
ottiylene  oxiiln  \»  \\»i\^ncf\  thin  cnnstitiitiotiiil  rormula  glvRii  above, 
boi-iiD8c<  it  yields  ethylene  nhloritlo  when  tmitei]  with  phoKphnrn* 
pentachloride,  the  oxygpn  iitom  hcing  rcpljiccd  hy  two  chlorinp 


atonu.     If  the  compouml  had   tho  coiistitution 


CU, 


which 


hnow 

Bi-emiinlHn  possiblo,  but  u,  howovvr,  lei«  prohnble  (136),  it  would 
not  /iel(]  ethylene  nhlnridn  when  thtis  treated. 

Some  cif  the  higher  hnmoIogHPs  of  glycol,  hetwenn  th« 
Iiviiroxy  I -groups  of  whi[;h  four  or  fivp  Rarbcin  atoms  intervene, 
yield  aiiliydridiis  with  a  constitution  unalogous  to  titat  of  ethylene 
oxido.  Thoy  ehow  a  marked  diniinutiou  in  tUo  power  of  fomiiog 
aflditinn-products  with  water;  or,  in  other  words,  the  clasetl  f-ham 
of  e-arbon  atoms  and  one  oxygon  atom  is  not  so  easily  broken  as  in 
ethylene  oxide  Itftelf. 

2.  Trihydric  Alcohols. 

157.  The  priuwpal  rfprouentiLtive  of  the  group  of  trihydrie 
ulcohnls  is  fflf/rerul.  or  i/l^rfri/ie.  CjlIj(OH),,  In  acroriinneo  with 
the  rule  given  above,  that  two  hydroxy] -groups  cannot  attach 
thcniwlvee  to  the  same  carbon  atom,  glycerol  can  only  have  the 
fitruiTtnre 

CII.OHCUOH  011,011. 

This  structure  finds  support  in  the  following  proofs, 

1.  On  earcful  oxidation  of  allyl  alooho!  by  menns  of  potassium 
pfrrmanganate,  two  UH-groupe  arc  added  at  the  position  of  the 
double  bond: 

CH,:  CII  Cll^OlI  —  CII,Ori  CHOH  CH.OH. 

a.  \fhen  glyeerol,  C,U,0,,  ia  cyiwrully  ox'uV\7Mr  t/ft/rtrrir  acid, 
C,H^Oj,  ia  fimi  formed,  eom-'spencling  to  the  foniiMtion  of  aeetin 
arid,  C,!t,0„  fmm  athyl  Hk-ohol,  t",ll„0.  by  evehniigo  of  two 
lijdrogou  atoms  for  onu  oxygen  atom,  whieh  nmkcnt  it  evident  that 
glyrend  rontiiiiis  one  — ClI,01I-gr(nip,  Fiirtiier  OAidation  Oon- 
verts  glycerii;  ucid  into  (artruHic  aci/f,  C,Il,Uj ,  two  hydrogen  atoms 
being  replaced  1^  ODC  oxygon  atom,  with   formation  of  a  new 


OUGMNtC  CHEMISTRY. 


carboxyl-group.  Heace,  glycerol  oontiuiiB  two  — Cll.OlJ-groupi 
iu  the  timU'uiiIe,  eo  thai  its  constitution  is  CH.OII  ■  C'11,0  CU.OII. 
Since  Uirtnjnin  a(!id,  COOIICIljO'COOH,  still  }>os*oejM.>«  alcoholic 
proport icii.  tho  group  CU,0  iniist  liavo  the  coustitiition  >CHOU, 
anil  t«iuco  it  must  liavo  tlie  tutine  cou^titutioii  iti  tho  moleeuli* 
of  givcerol,  the  structure  of  tho  latler  i^  proved  tti  \» 
0H,0il  CHOI!  CH.OH. 

'A.  A  further  proof  of  the  constitution  ji^ven  abore  is  tlic  forma- 
tion of  glycerol  from  tribromhyiiriii  (153>. 

Olycicrol  is  a  colou rkiM,  oily  liquiil  of  sweet  tiistP,  18  Torr 
hy^rnciivipin,  iind  miKc-ibk'  in  »11  pnijiurtiuus  with  wiit<*r  Riid 
alRoIiol.  but  insoluble  iu  i<lh<:>r.  It  MU'lidille^t  only  after  stAiuling 
for  some  tinitf  at  u  low  tcmpiTHtun-.  but  the  crystalH  thus  formetl 
do  not.  iiuilt  bL'I.iw  IT  .  IJ.  I*.  SaO".  sp.  pr.  1  2«'.  itt  15".  Its 
cbciniciil  bi-'baviour  is  oompletely  in  ncoorduucc  vrith  the  oonetita- 
tioii  of  n  trihydrio  akohol.  Tims,  it  yield«  three  c8tor«,  by 
replacement  of  one,  two.  or  thrw  hydroiyl-gronpn. 

Since  glycerol  is  a  subfiiaiicB  wliieli  plays  n  very  imporlniil  part  iit 
tbc  o.-miomy  nf  imtiiru  ns  »  cuitsliiiintit.  of  iIk  ftiH  (IM),  its  symlicaiH 
fram  its  dtMuimis  m  of  grcnt  inlvrtMt.  Tliis  wa«  efftH't*>d  by  Fkiedel 
and  S[LVA.  The  slnrtinK-Ewiiit  was  acetic  octd.  Thin  cau  tie  ayuijie- 
aized  from  iU  el«me>ril8  in  ssveniJ  ways,  for  example  by  tho  (ixldntinii 
of  ucoWkleliydfl  obiAitifld  by  Uie  mivm  of  WHUtr  on  «wiyl«iio  (US). 
Tli«  dry  iliMLillalion  o(  uiiliiluui  niittnlo  gave  aciviono,  whicd  was  rtv 
duood  to  iaoprapyl  alcohol.  Ou  diminatiou  of  walor  from  tlie  latltrr. 
propylfltie  wns  furmiMl.  whidi,  on  additiou  of  chlorine,  was  oonvprtivl 
Into  ]in'jpylnne  dinli]i>ri<Ie,  from  whhii  triRhlnrfaydrin  yuan  ubtniiii-tl 
by  uwatiii«>nt  with  indino  chloride.  Trichlorhydrin  wax  convvrl«d 
into  glycerol  by  liciitiiig  witli  watt-r  iit  170': 

CH.-rOdll  — {;H,C()C!H,  — CH.CHOHCH,  — OH,CR:Cn.— 
—  ClI.cnci.CH.Cl— CI!,t'I-Cncl.Cll,CI  — CH,OH.CH01I-CI1,OU. 

i'ri>|>|'lpiir  lUrhliinilr  TriclilixliyilrlD  QlyoVTOl 

1S8.  Seviirnl  compouuda,  dirtioult  to  prepuro  from  any  Qtlipr 
sulwtjincc,  may  be  obtained  from  ffl>'«*rol'  Amoiig  them  may  he 
mentioiivd  allyl  ttlcohol,  uUyl  iodidi?.  a-i-rolwin,  and  isopropyl  iodide. 
.lllt/l iih:ofiol,  ClI,:CU-CU,OH,  can  be  obtained  from  ^reerol 
by  heating  it  with  oxalic  acid,  COOH  ■  OOOII.  Tho  nionoronnic 
acid  alter  of  glycerol,  tm»of'ormin, 

CH,OHCHOHCH,OCO        or        CH,OIICH  OH-OH, 


CLYCBROL. 


181 


it  firel  form*^,  an  iindRr  thptie  conUttions  oxalio  acid  litaes  one 
inoleeule  of  CO,.  >ii)Idiug  foriiiii!  acid,  UtKJlU— COQU,  which 
I'liiiibinos  witli  tlio  glvi'iTol  to  prtHluce  nionoforiiiiii.  When  he«t*d 
iiitire  Btroiigly,  thin  (leoyiiiiKieus  inlo  allyl  alcohol,  water,  and  i^r- 
bon  dioxide : 


UH,OH.C'H 


0H|CH,|O^CO, 
H  1 


OT         CU,OE-_CII— CH,|0]ll 
lO-OOiE 


AUgl  i'tdide  is  obuiinod  by  the  action  of  phosphorus  and  iodine 
on  anhydrous  glycorol: 

9H. 


CU,I 


CH. 


CllJOII 

CH  OH  +  PI,  =  CHI  +  P(OH).;     CH 


ClI, 


OH 


CH,l 


CH.I 


-  31  =  IIh 

CH,I 


The  tri-iodiiydrin,  C,HjI,.  which  is  proUbly  [orm«d  as  an  inter- 
nti?diat«  |iraduct  in  thU  rt'iuHiuii.  is  iinKtublp,  and  atouce  loseH  two 
utoms  of  iodine,  yielding  tdlyl  iudidf. 

Acrolein  (L47)  is  formvd  by  tlie  elimination  of  water  from 
glycerol : 

loiTirl 

CH,C— CIIOU; 

iOH~H| 

whereby  CH,:C:CBOn  should    rceitlt,  but  inuuediatiity  chaoges 

iiiU.  acrok-iu,  Lil.iCH  cJJ  (136). 

hopropt/l  iodide  \s  formed  by  the  addition  of  water  to  a  mitturo 
of  glycerol  with  iodine  and  phoBphonis.  In  this  roaotion, 
pmpylerie,  CH.CH  :CH,,  in  formed  iis  nii  i (itemed iate  prodiint, 
and  is  evolved  in  ibe  frt-o  statu  when  care  is  not  taken  to  have 
sufBcieut  hydriodic  acid  present.  By  the  addition  of  HI,  pro- 
dnfed  by  the  iiitenvrtion  of  iodine,  phoaphoms,  and  water,  ieopropyl 
iodide  \i  formed  from  the  propylene  thus  generated: 

err  ■  CH  :oii,  +  HI  =  CH,- cm ■  cii^ 

Vrr-fy[i-nif  Iwiprojiyl  lodlila 

Fonnic  acid  (86)  is  usually  prepared  by  the  action  of  glycerol 
on    oxalic   acid.      As   mentioned  aboi-e,  when    these   siihBtancea 


iSi 


ORGANIC  CHEMISTRY. 


are  hewted  trOgether,  carbon  tUoride  is  evolved,  aud  the  glyceryl 
ester  nt  formic  acid  produced.  Formir  acid  is  obljiineil  from  the 
latl«r  l>y  sapflnitie^itioi],  the  glycerol  being  regenernled  at  Ilia 
same  time.  This  li  best  curried  out  by  the  ndtlitiga  of  a  ir«*h 
f|»iantily  o(  oxalic  aoid,  C,H,0,,  'iw\,  whose  water  of  vrystalliza- 
(iDT)  flllticrls  the  aapniitiiL-ation  nf  the  eater,  the  formic  lieid  dis- 
tUliug  nver.  The  glycerol  thufi  regenerated  is  again  conrerccd 
into  monoformiu  by  the  freahly-HiIded  oxalic  acid,  and  the  ester 
once  mure  deROnipoeud  by  the  nddition  of  a  further  r|U.intity  of 
ostdiu  Rcid,  etc.  H  ia  iu  this  w&y  poieible  to  convert  unlimiled 
quantities  of  oxalic  acid  into  fomtio  acid  by  moans  of  a  given 
quantity  of  glyccrnl. 

lOS.  CTlyrrerol  exi^t»  in  nature  in  large  qtiantitioe  in  the  form 
of  esters.  The  fats  and  oils  are  glyoerjl  tri-esters  of  lUe  higher 
fatty  acids,  and  of  nle'i'c  arid ;  glycerol  and  the  fatty  acida  are  ob- 
tained from  thetn  by  anponificAtion  (91  and  101). 

The  !Uiponil)(Mili<m  of  (bo  iH-tslora  of  glycerol  with  caustic  soda  <«■ 
[jmc.  talcct  |ilace  in  alagos,  tho  di-iMierB  and  inoiio-eotert  being  forneU 
aa  IntermcMJiate  products;  this  may  tie  proved  a»  fullow^  On  ooiu- 
plet«  saponification,  pure  tristeaiiti,  at  gl/i^t^iyl  tristcarute,  yields  only 
8teuric  add  and  glycerol,  aa  thai  if  no  intcnut-ilintu  products  are 
rormixt,  a  pivrtinlly-siipDnlfled  portion,  in  which  tho  soap  produced  liiis 
been  dtcoDipoBcd  by  hydrochloric  arid,  mid  llio  glycerol  rtmo^eii  liy 
washing  with  wal<^^,  sliould  cnntnin  only  imchanRcd  TriM4>arin  anil 
stearic  acid.  KeiiluT  i  HMi-iiHn  tmr  sti-aTicncid  can  vii.-hl  aculyl-dcri en- 
tire* wiih  ac«tt{-  Jitiliyilridc.  If  ihn  itii|M>tiillctition  lake  plado  in  singra, 
inutioatoariu  and  disli'.-iriD  woidd  bv  formed,  and  tiio  froe  bydroxyl- 
groupsof  theglyceryl-reiiiiltio  in  these  coiopoiinds  would  rmot  with 
acetic  anhydride  (o  form  acetyl -com  pounds.  On  Ireainient  nilb  Ibis 
antiydndc,  and  c(ul)Ne(|Uenl  complete  wipouillcatiaii,  acetic  aeid  would 
be  (iinoiig  the  pniducta:  it  baa  \kvi\  sliown  by  experiment  tbal  ibis 
acttiiiliy  tlocs  ocunr. 

rtiTcrscly,  the  fata  can  be  synlhoeized  from  glycerol  and  the 
fatty  acids;  for  instance,  tristmrtn  \i  obtained  by  heating  glycerol 
with  uxoBHs  of  rtearic  acid  under  reduced  preasuro  at  SiMi'  until 
oepamtion  of  water  cBases. 

When  kept  for  some  lime,  many  fata  boconio  runad.  and  develop 
u  diHtigrvvuble  Hmcll  and  tiuto.  Tliis  \a  due  to  atiuuaphcriu  ojcida- 
tiou.  which  is  lacilitated  by  the  inltiiettce  of  light.  The  uuatu- 
r»te<l  fatty  acid»  become  couvertfd  into  uLhera  cntitaiiiing  a  smaller 
number  of  carbon  atoms,  aiid  wilhai  charauteristic  odour  and  to^te. 


^ 


>^; 


WTROCLYCBRINE. 


lii 


160.  Cilj-cerol  is  oxtonaively  employer]  in  the  art«  and  in 
mwlit-'im-.  One  of  its  most  import»nt  uses  U  for  tlie  prepjimtion 
of  the  tto-callBd  "  iiitrnglyreriiie. "  TliiiteiptoHiTO  biua  misleadtug 
uauie,  fiino«  it  ia  glyccr;!  triuitmtv, 

CH.ONO, 

CUONO,, 

6n,0N0, 

TkI  not  a  nitro-com pound  (76);  lor  tin  saponification  with  ulkulis 
it  yields  glycerol,  uud  ttif  itilrutc  ot  the  correepondiug  ulktili-Divtul. 
Nitroglycerine  is  propiired  by  bringing  glyoorol  into  contact 
with  n  iiiixturo  of  conccntratod  Rii1[>liiirio  mid  nitrin  ar.\d».,  cnro 
leing  wken  to  avoid  a  rise  in  WnipRmttirp.  After  u  time,  tlie 
waction-miittire  is  ponred  into  water,  whereupon  the  uitnit* 
wparates  in  the  form  of  an  oily  liquid  of  f»int,  hRuiIar^hd-pro- 
dncing  odour,  and  t^an  be  puritii^d  by  wushiiig  with  wutur.  Wtiou 
perfeotlj  pare,  it  docs  not  explode  epoutaneoiisly. 

Nil ruK'yeerine  ia  a  li<q,iiid.  mid  a^  lis  use  in  lliia  lotm  for  tMbnical 
porposM  would  bo  miended  with  dKBculiiea,  it  is  mixed  with  infu- 
sorial cnrlh  (kittselKubr},  wliicli  iibaoriM  it,  foniiinic  »  soft,  plwtic 
IDMS&,  tttpmmUt,  coniMinlng  itttiuiHy  752  of  nlirriJijlyctiriDt!,  and  Oii  of 
tli«  eanti.  Ni trolly er.riao  can  tAso  In:  obtniiiud  lu  tlie  solid  fortii  Uy 
diasol ring  ill  it«fimiillaniiii)nr>'i  Liuncorton  (2311.  wUicbcinivtrriHii  into 
Ml  einatio  solid  rcsombling  jujubes  in  conaistcncc.  called  "blastiug 
gelatine,*'  Thia  Kubsianee  baa  tlie  advantage  ovi>r  dynamite  of  not 
IcBviug  niiy  aolid  resiJne  after  cxploBion,  Dynamite  cannot  be  used 
as  ainiuuiiitloii,  lU  velocity  nt  tiX[)I(»tlon  Imiiiir  fio  ((real  as  to  prndnce 
an  inapolso  too  vtolcut  fur  h  guu  to  resist  williout  burstiuf;;  ttiat  <^j>t^ 
exerta  a  hruant  effect.  "j^^^l^^ 

3.  Tetrahjdric  and  Polyhydric  Alcohola. 

161.  Among  the  letrabydric  ulcohole  may  be  mentioned 
trtfthrilol,  CH,0n-CII0H.CIIOHCU,OlI,  which  iK  a  luitiiral 
piodiiot.  That  it  contains  a  normal  carbon  chain  in  provvd  by  \u 
oonTcraion  into  w-aocandary  bntyl  loiiide,  CII,-C'III-CU,-CII,.  on 
reduction  with  liydrioilic  acid. 

Examples  of  peiitahydric  alcohols  are  aroMol  and  irr/tilol. 
C.H  11^,  which  are  aturi'olsomerg.  tw  are  alwi  tho  hoxahydric  n\v.it- 
hoW  dtilatol  an/t  wannttol,  C,II„0,,.b6th  of  which  aru  found  in 
natiire.    Tliwse  all  haYc  normal  carbon  chains,  sin™,  liko  crylbritoi. 


184 


ORGANIC  CHEMISTRY. 


tliey  yield  n-secondnry  iodidf-B  on  redaction  witli  bjilriodio  acid; 
for  example,  mannitol  U  converted  ioto 

OH,  -  cu,  ■  cm  -  cn,  ■  c'li,  ■  cH,. 

Thny  can  ke  obtained  artiftciaily  by  tli[t>  n-diicUoQ  oX  the  corre- 
ajiondin^  atdehydes  or  kotones.  Tlie  rcasott  for  ftadtuniug  thvir 
stfreoiBonieriom  wiU  ap])«ar  luter  (21S).  It  id  miflicieut  to  retuurk 
bore  that  tbe  polyhydric  nlooliols  t-ontain  asymmetric  ctirbon 
atoou),  itidiuattid  in  Ihu  fulluwiug  formulai  by  luiterisks: 

cH,OH.SHoncnoH.5uoii  Cn,OH; 

AmhiCol  and  \j\ilvl 

OH,OU-(5hOHCHOH   (*110]I-riI0H.CE,0n. 

Thv  preeeuco  of  polyhydric  alcohoU  prevents  the  precipitacEon 
of  tilt;  Baits  of  copper,  iron,  and  other  meiald  by  means  of  alkalis; 
tbus,  A  tiolution  of  copper  euljihato  to  which  glycerol  has  be«ii 
added  does  not  yield  a  preoipitale  of  oop]wr  hydroxide  with 
canittie  potash.  Thie  is  due  to  the  fonnatiun  of  soluble  metallic 
pompoiinds  of  tho  polyhydrio  alcohols,  whose  liydroiyl-hydroKen  is 
rrplacijd  by  the  metal.  ThU  projHrty  is  not  only  pomw«ed  by  the 
polyhydric  alcobo^  bnt  aUo  by  many  other  compoundscontaininj: 
oevorul  hydroxyl-groupa  (l&S). 

IT,  DEBITATIYES  COHTArsraO   HAtOOEM    ATOM.  HTDBOXTL-OmOIIFS. 
HITSa^BOUPS,   OK  AHIDOOSOnPS. 

162.  Wc  shall  only  consider  »  few  of  the  nnmcroua  compouudtt 
belonging  to  thin  rlasa,  of  which  it  may  be  said  in  general  that  tho 
chemical  propertieia  of  ite  membors  arc  determined  by  tlie  siib- 
stituents. 

No  compoimda  containing  liaJogon  and  bydroxyl  attached  to 

the  same  carbon  atom  are  known;  when  their  formation  might  be 

expected,  halogen  acid  is  split  off,  with  ]irodnction  of  iddohydes  or 

ketones.     It  lia«  more  tlmn  once  been  moittinned  that  stable  ulkyl- 

dcrirativcs  of  compcnnde  tbemsclToi;  unstable  or  unknown,  such  »d 

the  ortho-estcm,  exist  (168).     Thiti  is  true  in  this  instance,  for 

CI 
while  compounds  of  tho  tTpoU-CH<Q|,  are  onknown,  deriva- 

Cl 
tivee  of  the  formula  R-Cn<jj  j,  .,        are  known.     Thcso  Roh- 


CHLOROETHBRS  ^KD  H^iOGFNHYDRINS. 


>8S 


JiniceB  nre  called  chiororlhers.    AVhon  ohiorino  is  paasoil  iolo  otbyl' 
ether,  which  is  liept  cool  aiii3  nway  from  tlio  action  of  lighi,  to 
avoid  p-iplosioii,  tlie  hydrogen  ntoniB  are  replaced  bj  cWorine;  the 
monoenbetibutetl  protliict  has  the  conHtittition 

CH,-CH,0CHC1CH„ 

Uvu<>cli1or««Cb*r 

» 

ti»  is  proved  by  the  aetion  tA  iinlphnric  acid,  under  whoso  influenca 
it  takcH  lip  one  moluculi-  of  water,  forming  ethyl  lilcohol,  aceCalilc- 
hydc,  and  hydru<:hloric  acid : 

C,U.  II         C.IUOH 

>0+   I      =       +  p. 

CH..UHCI     OH       t;iL-CIi<J;i,=C3,.CH0+Ha. 
MciOiwhTQPiwUwr  "" 

Compoimds  containing  halo^n  uud  hydroxyl  attached  to 
different  carbon  atoms  are  obtained  from  the  polyhydric  alcohols 
by  partial  exchange  of  liydroxyl  for  halogen,  and  have  the 
geiKTul  ii!itiio  halogen-htfdrins.  Tho  dichtorhydrin  of  glycerol, 
C\Hj<OUjC'l, .  ia  foruifd  when  a  soluiioii  of  glycerol  in  glacial 
acetic  acid  b  mturated  with  hydrochloric-acid  gaa.  It  haa  the 
Bymnictrical  formuhi 

CII,Cl.CHOH-CH,a, 

since  it  differs  from  the  dichlorhydrln  obtained  by  addition  oi 
chlorine  to  ally]  alcohol,  this  having  the  mnHtitntion 

cii,<)ir.oiif:i.oii,a. 

On  treatment  of  the  nns^nnmctrical  dichlorhydrin  with  caustic 


potash,  epiclthrhydrin,     \ 


0H,.CH.CH,C1,  , 


^ 


ia  obtained. 


iHnitro-cvtnpounds  in  which  both  nitro-gronps  are  linked  lo 
the  name  carbon  atom,  arc  obtainod  from  primary  bromo-uitro- 
compoiinds  bj  the  actiou  of  potatwium  nitrite : 

CH,.CHBrNO,  +  KNO,  =  CH.CUtNO,),  +  KBn 

Tho  hydrogen  atom  in  nnion  with  the  carbon  atom  carrying  th^ 
nitro-groupB,  can    be    readily  replaced  by  mt^tuls,  ao  that    thc-so 
primary  dinitro-com pounds  hare  an  acidic  character  (281). 

/'laj/iiiffs  in  which  thelwoamidn-grotipxnrcattadioil  to  tlioaiinio 
carbon  atom,  are  uot  nuiueroiis;  ino&t  of  them  have  their  atrildo- 


'iS6 


ORGANIC  CHEhllSTRY. 


groups  attAched  to  ttifferent  orbon  utoms.  Some  of  these  com* 
pounds  nre  fornie<I  by  the  putrefaction  of  animal  matter,  such  ttA 
fiesb,  and  are  cUsflod,  witb  other  baeic  (ftibfitftucoafonncd  in  the  same 
■way,  aa  pUma'iiw,  Among  Ihom  may  b«  mentioned  aidavtrim 
{pmtamethylenedianiiue),  NH,'C'H,-(CH,),'CH,-XH,.  and  putre- 
tctju  {Mrameihtil»ufdiaini*u),  Nn,.CH,.(CH,),.ClI,.Xll^  The 
oonKtitutiou  of  thi-«e  subetances  ha«  been  proved  by  synlbbsjii.  penta- 
mcthvleiicdlamiiii.'  being  thns  obtained:  trimethylene  bromide, 
Br-t'lI,-t'H,-<iI,-Br,  is  oonrerted  by  treatment  with  potassium 
cynnidc  into  trimethylene  cyanide,  CN.CIT,CH,.CH, -CN.  Thin 
gubRtaneo  is  rtnluccd  with  sodium  and  boUing  akohal.  which  coii- 
veru  the  CN-groups  into  CU,NH,-gioup8  (89),  with  formation  of 
the  iliMDine: 

CN  CM,NH, 

(CU,K  —  (OH.),    . 

Cn  Cii,nh, 

Wben  pentametiiylencdiamiue  hydrochloride  is  heat«d,  it  loses 
on«  molecule  of  ammonia,  and  is  converted  into  piperiditWt  which 
hae  thb  cliaTficl4!r  of  a  satuntted  eerondnry  amine  For  thit;  noil 
other  reaKuus  (387).  it  U  assigned  the  riD£>formiila  given  in  the 
following  eqnation: 


V*H.CH,NH,  VH..CH. 

IVniAniBihylBiiRllamliiB  llperMlne 


rWben  heatc>d.  tetmmothylenodUmine  and  irimethylenediamine 
yield  analogmiB  uloaud-ehuiii  compounds,  but  less  reidily,  whereas 
ethylenetliamine  i&  iuuipablo  of  doing  so. 
A  mbstanco.  partly  omine  and  partly  alcohol,  fibooM  bu 
rt'ferre<l  to  hcry.  on  account  of  its  physiological  importance;  it 
ia  chahne.  C^H^NO,,  which  u  widely  diHtribnted  iu  llio  vegeta- 
ble kiuj^om.  Its  constitution  is  infetrod  from  it«  eyulhesis  by 
the  inUiractton  of  trimetbylamine  and  ethylene  oxide  iu  aqueous 
solution : 

(CH,),N  +  CII,.cn.  /CH,.CH.OH 

OUU         0  *"  \ou 


LECITHIN.  187 

Ethylene  oxide  can  also  combine  with  anbstances  like  ethyl> 
amine,  witti  formation  of  ami  no-alcohols. 

Choline  is  a  conatituent  of  a  Tery  complicated  aubstance  called 
lecithin,  which  is  present  in  braia-matter,  and  also  in  yolk  of  egg.  On 
treatment  with  dilate  aoida,  lecithin  is  converted  intooboline,  and  a 
tri-ester  of  glycerol,  glycerophoaphoric  acid  diatearaU, 

/OCO-C„H„ 
C,H,f-OCOC,,H„. 
\OPO{Ofl). 

LecitblD  is.  therefore,  the  choline  salt  of  this  oomponnd. 


POLYBASIC   ACIDS. 


I.  8ATTTKATED  DIU8IC  ACIDS,  CaHtn-tO,. 

163.  Many  immera  of  the  actds  C„H^(C00n),  are  theoretically 

poasible,  and  HitTf^r  frnm  nno  another  in  the  positionci  at  which 
tlte  carboaiyl-groiijie  arc  linked  to  the  cwWn  cbaiu.  For  mauy 
reaeons,  the  mo^tt  iin|H>rtanC  arc  those  whose  carboxrl-groupe  are 
m  imioii  with  llii-  ti»rmiiial  carbou  atom  of  ihtf  normal  <.'haiii, 
th«  cuQ/'-ucids  (164).  On  this  ttccount,  these  will  he  described 
here. 

The  j?oncnil  methods  for  tho  prrimnilion  of  the  dibasic  and  the 
monobtieic  acids  iiru  analogous,  Tlie  lorun^r  an;  jinKltiwd  by  the 
oxidation  of  the  oorresponditiK  fClyi^ol^  bmA  .-iMchydce.  and  by  the 
bydrnlysis  of  thi*  dinitrilcs,  althoufth  many  of  thom  are  prcpiired 
by  Hjwni&l  tn(>thods. 

Physloal  and  Cliemioal  Propertiai. 

164.  These  acide  arv  wdMt'gned  crystalliae  siibetancva:  those 
contaiiiiug  more  thuii  ihree  carbon  ntoroti  can  bd  distilled  in  vacuo 
witboui  dopompoettion.  Many  of  thom  split  off  water  when  dis- 
tilled undi>r  ordinary  prei»iire. 

The  melliii^- points  of  these  acids  eihibit  the  same  peculiarity 
n8  those  of  the  tatty  s<^ids  (67) :  the  inctubers  coutuiriiu^  an  even 
number  of  carbon  atoms  have  higher  nieltiiig-pointa  than  thoee 
immediately  iiuveeodinf;  then],  with  an  uneven  nnmherof  c*rbou 
atomii.     Thia  iii  seen  from  the  table  on  p.  1^!). 

ThiK  relation  ii<  jrraphically  represented  in  Fig.  .^l,  from  which 
it  i*  HOon  Ihut  tlic  melting-poiiitH  of  the  even  and  uneven  eerios 
approxinuite  mure  and  more  elondy  as  the  nnmhor  of  the  rarbon 
tttome  incrcMWi<. 

A  eimilnr  jvceniiarity  is  displayed  in  the  eolubility  of  these  acids 
in  water,  given  in  the  lait  enliimn  of  the  table.  The  eoiubility  ol 
the  aeidn  with  an  unoven  nuDiber  of  carbon  atoms  is  much  gi'eatvr 

iS8 


n 


I 


X 


SATURATED  DIBASIC  MODS.  C„II,„.,0,. 


189 


\ 


Forniul* 

palnt. 

hvu  by  WBiKhi  Hohiblt 
in  100  Panm  of  WKur. 

COOH-fOOH 

COtHl.CH.COOII 

CtM>li-ii:»l,l,.(-0OH 

(_tK>HlClM,-C<X»n 

tOOH-iCUiVCOOIl 

(.XK»H(tH,i,fOi;>H 

(X)0ll-(ril,i,-(X'OH 

coon.(Cii,>,fO<>ii 

COOII-(CII,),-C(«Hl 
C0OII.(flI,)„.(»OH 

cyoii.((  ii,,..-ciK)ii 

C0OH.(CH,>„.CO0H 

1B9'» 
132- 

isa* 

67-5- 
149* 

loa* 
]«• 

108= 
188* 

laa* 

US* 

isa* 

19- S    al  SO* 

,^SI»Utnic«eid 

7  Adlpic«cld 

189. S7   ..  15* 

5-U   ..  14.5* 
80. 3     ..  U' 

1-44  ..  in* 

Plnteltc  Bc'icl 

4-1      ..»■ 
O-IU..  15-V 

Ueouncib  V  l*n». 
■lintrboi;rlk  uld.. 

L>nd  wkutti  ti  r  i  «i)<^ 
dIcarimsjCic  ncid . , 

0.1    „  ir 

•  Anliydroiu  rmaMn  mM, 

than  the  solnbility  of  thofi*  witli  an  even  number,  ami  it  iliminishea 
in  both  cas«s  as  the  uumber  of  fiirbon  atams  ini'rtiRRPR. 

Oxalic  Rcid  U  &  ver;   much  ntrongur  acid   than  its   higher 
homoIogneB,  as  is  ehown  b;  the  HiBEnriiition  constants.     For  oxnlio 


t     10 

nuaaui  or  OMWX  atOM 

PW.  SJ.— OBAPHIC  HEPIIKSCHTATIOK   ok  THK   Mia.TISO-l*ulS|-s  UK  TWB 
ACIDd  folI.n-i<J. 

acid  K  is  about  lO-O,  for  maJonic  «cid.  0-10.3,  and  for  succinic 
ifccid,  0-W)05;  for  tli«  rcnminitig  acids  it  Ima  vuhioa  which  dimiuiah 
with  incmue  in  tlio  inimtiBr  of  cnrtion  atuuie..  but  are  of  thu  same 
order  as  the  last  nuraber.  The  further  the  CHrboxyl-groups  are 
remorcd  from  each  other,  tbo  weaker  is  the  acid. 


190 


ORGANIC  CHBMtSTRY. 


Oxalic  Acid.  t-",ll,(t,  +  211,0. 

166.  Between  uxiUic  acid  »iid  formic  ac-td  there  exists  a  genetic 
intcpk-iii'udcufc;  it  is  possible  to  iircpuro  formic  scid  from  oxalic, 
or  couvtTH-l)',  uxuliL-  from  fonniti  ucid.     Ou  rapidly  liiuLtiiif;  j>(itMi»-,J 
slum  or  sodium  furmnte,  bjdrogcu  it  evolved  from  the  fusiug 
mau,  and  potassium  or  sodium  oxaliLte  is  formed: 


KOOC 

KOOt 


KOOC 
KOOL- 


+  Tr, 


The  rererse  transfonnation  of  oxiJic  iiilo  fonnic  acid  b»e  already 
deecribod  (198),  tuid  coiistitnt««  Che  ordiuary  methotl  for  the 
preparation  of  formic  acid. 

Oxalic  acid  m  freqiumtly  produced  l>y  tliv  oxidatiou  of  urgaiiic 
Kubglfitiree  with  nitric  atnd;  tlius,  ii  is  formed  by  tb«  acciou  of 
lliis  acid  on  sugar.  It  is  prepared  on  the  maim faclu ring  scale 
by  heatiiij;  a  mixture  of  caustic  potaeh  atid  caustic  soda  to  the 
poiDt  of  fusion  along  with  sawdust.  A  formate  is  produced  m| 
ail  intermediatu  product,  and,  un  further  lieutin;^.  luaea  hydrogen, 
and  is  conrertud  intu  an  uxukte.  After  cuulitig,  the  m&sa  is 
lixiviatetl  with  water,  the  oxalute  j^uiug  into  iiolulion;  the  oxalic 
acid  in  thou  pn^^ipituted  bh  t-aldum  oxaIat«^  by  the  addition  of  milk 
of  lime,  and  tiuully  obtaiuud  in  tliu  fri-v  statu  by  the  action  of  sul- 
phuric acid.  ^ 

Tiio  prodnetioQ  of  this  acid  by  tho  interaction  of  carbon  dioxide 
and  potassium  or  Hodium  at  about  300  ',  and  its  fomiation  by  tho 
hydrolym  of  cyanogen  gaSjCN-CN,  are  of  theorotieal  impor- 
ftnoe. 

Oxalic  acid  is  found  in  nature  in  different  plants,  chiefly  in 
species  of  oxatia,  in  the  form  of  pottuseium  hydrogen,  or  calcium. 
Bait.  It  is  eometimea  found  ae  n  crratalliue  deposit  of  calcium 
oxalttte  in  plant-celU  It  cryatallizM  with  two  muitfculea  of  water 
of  cryetalliaation,  which  it  begins  to  loeo  at  30°.  The  anhydroua 
acid  can  be  mblimod  by  careful  lieatiug,  but  when  strongly  heated, 
either  atone  or  with  coucentra^  sulphuric  acid,  decompofivd  into 
CO,f  CO,  and  11,0.  The  same  decomposition  takes  place  wlien 
a  solution  of  nranium  oxahitc  is  exposed  to  sunlight,  CO  and  CO 
boing  onorgcticuUy  evolved.     Oxalic  acid  is  very  easily  oxidised;  a 


■  93 


ORCANIC  CHEMISTRY. 


The  following  derivati'vcfl  of  oxalic  ftciil  are  worthy  of  moiitiori. 
ThD  dimethyl  et.ter  is  solid,  M.  P.  f>i',  niii]  va  used  iu  th«  prepani* 
tinii  of  pure  mRthyl  alcohol;  the  diethyl  tttar  \i  &  liquid.  Both 
ure  prejmrcd  hy  diBtilliitg  h.  itolution  of  unln'drous  oxiiliu  acid  in 
thu  absolute:  alcohol.  The  umido,  oxauiidr,  ('ONn,-CUNU,,  U  tt 
wliiU;  Kolid,  nearly  iiieolublv  in  wuivr,  alrohul,  luid  ctbur,  and  U 

^obtained  ab  a  cryfitalliue  (trccipitnte  by  the  A(i<iition  of  ammonia  to 

'ftsolutiou  of  II  diiUkj'I  oxuLtto. 

The  monoaniidos  of  tlio  dibasic  acids  nrocallod  omic  aeidg,  that 
of  oxalic  acid  being  oxamie  acid,  CONH,-C00ll.  It  19  a  riystaU 
llue  compound, readily  soluble  m/A\d  water,  and  insoUible  iu  alcoliot. 

Malonic  Acid.  COOH-CU,.CO0n. 

168.  The  constitution  of  mclonic  acid  is  proTed  by  its  eyntheeU 
from  nuraoohlorotMwtic  acid.  Ulieii  un  ai|Uouui!  Dolution  of  potas- 
sium monoi^hloroncvlalo  is  boUud  with  jiolJii«ium  cyanidn.  t-yuno- 
acetic  mrid  i*  formed,  and  ciiii  bu  couverled  iuto  malonic  acid  by 
liydrolysis  of  the  mtrile-group; 


'*^^'<COOH 


Honoohlorotuado  oaliil       CvjrBooMvtlc  acl<l 


Molojnii:  add 


Malonic  acid  Is  a  crystalline  n-ubstance;  its  physical  pro|iertioa 
will  be  found  iu  the  tablu  on  page  ISit.  VChvu  lieated  ii  little  abme 
its  melting-point,  it  loses  one  molecule  of  carbon  monoxide,  being 
converted  into  acetic  acid: 

cooii.cn,.ico6iH  =  Go,-i-cooH-cn,. 


Bzporionco  shows  that  vt/ien  compounds   in  which   two  etirboryl'i 
groups  are  m  unw7i  with  otte  carbon  atofn,  are  heated  ab</ve  thtir 
meliinif-jwints,  each  molecnl$  loses  one  moUi-ule  of  carbon  dioxidt. 

The  most  important  com]ioniut  of  malonic  acid  is  tU  diflhy) 
etttr,  on  account  of  tlio  many  impoTlunt  *<\iithoae8  wliicli  can  W 
accomplished  by  ita  aid.  It  ie  u  liqnid  of  faint  odour,  boiling  at 
19R*,  and  having  a  specific  grsrlty  of  I  -(.itU  at  15".  On  IrL-atmcnf 
with  sodium,  in  the  proportion  of  one  «tom  to  each  molLvule  of 
eitter,  hydrogen  ia  evolved,  and  the  malonic  eeter  converted  into  a 


MALONIC  ESTER  SYNTHESIS. 


193 


wlirl  mass.     In  tliU  rcnction,  hydrogen  u  rcplaood  by  sodium, 
jieldiiit;  sodiomaionie  enter,  n  compociiid  of  the  etructaro 

cooc,n, 

ClINa      . 

cooc,n, 

This  is  proved  by  trenting  it  with  an  alkyl  haJide  (iodide),  by' 
which  sodium  luUide  anil  an  eeter  are  obtained; 


C,n,>l  +  yajCK(COOC,H,),  =  C.Hj.CJJ(COOC,Hj,  +  Nal. 

On  snpoiiificatiou,  thU  ester  yields  a  homolo^e  ai  matonic  acid. 

If  two  atoms  of  sodium,  intjteml  of  one.  ruact  with  oiiv  moluculc 
of  uiaJonic  ester,  tvo  hydroj^ti  atoms  are  rc-pluct'd.  Both  of  these 
hydrogen  atoms  are  in  thu  methylene 'f^r>iip,  boonuse,  on  treAtniont 
of  thu  disa<)io-c.-ompc>iind  with  twn  molcculps  nf  an  nlkyl  iodide, 
the  two  sotlituu  atomH  are  replaced  l>y  alkyl,  nith  produrtion  of  a 
subscaucc  which  ou  isaponitictttiou  is  converted  into  a  homologuo 
of  maloQic  acid : 

CQOC,n,  COOC.H, 

C|Na,-)-2lIC,IT,=  2NaI+  C((.,nj.  . 

i;oof,u,  cooe.ii. 

It  IB  also  possible  to  introdnrc  two  difF<>n>nt  alkyl -f^nnps;  into 
malonic  eeter.  Thus,  when  manoiiodionialunit:  eHter  is  tresited  with 
imih^l  iodide,  tbectiti;r  of  methylmalonic  arid  i«  formiHl,  which  on 
tre»tmcnt  with  sodium  u^tiii  yields  a  aodio-compound;  this  ia  con- 
verted by  ethyl  iodide  iiiio  iho  ester  of  ethytmcthylnuilonifi  acid. 

It  i8  ofidont  from  the  oxamploK  whieh  IiaTo  boon  given,  that, 
with  nudoiiic  tyiior  as  a  starting-point,  it  is  possible  to  Bynthmize  a 
greni  number  of  dibasic  acids.  Moreover,  «ince  all  these  acids 
contain  two  i^rboxyl •groups  linked  to  the  same  carb^in  atom,  and 
have  in  nommon  with  mnlnnic  acid  the  pmperty  of  losing  CO, 
wlieu  boated  above  tlwir  moltiti^-poiuts,  it  is  evident  that  the 
maloDt«  eeter  sytithesis  i»  aleo  available  for  the  preparation  of  the 
monobaaie  fatty  aeidft.  For  etample,  mcthylt-thylmaloniL'  ucirl 
loses  CO,  ou  heating,  yielding  methytuthylacotic  acid,  ideutical  in 


bOA 


■94  OKCANiC  CHBMiSTKY. 

owiBtimticn  with  active  valeric  acid  (61).     It  can  be  naolved  into 
ito  two  active  componenta; 

COOH  COOH 

OII,-C-C,n,  =  CH,-C-C,Ej. 

The  malonio  ester  BviithesiB  is  one  of  the  most  general!^ 
applii^nhlc  iiiethofis  for  the  preparation  of  acida,  aod  it  will  b^ 
frequently  neceaaary  to  refer  to  it  later. 

ViCliod  of  s»rr7JDK  «iit  dio  mftloiuG  wUr  ■jrnthotli.  — Thb  it  kiways 
•Qei-'ti'il  ill  [III-  rulluwiiig  wiij'.  Uiiu  graniiue-iwilttculv  of  iDHl»nf<!  rsler 
is  mixod  with  a  ten  j>er  cent,  solution  of  scKliimi  otlioxidt'  (L  c<)UiTiilen(> 
in  absalulo  Alcobol,  obtaiticd  by  tim  ac^tion  of  smliuni  on  alcobol. 
To  this  mixture  ie  added  oa«  (ua.miue>molecul6  of  «n  alkyl  iodide. 
And  the  reaorlrni'inixture  heated  no  a  water-bath  under  a  reflui> 
0»ndei3Mr  nnljl  the  liquid  I*  n<>long«r  alkAlin«.  Aficr  th«  nl^ohol 
bas  b»eii  dlstillftd  off,  tliE»  mldui>  is  troHtcd  witli  wa.tvr  to  dissolw 
the  fiodlnm  lodlilrt  fomnpd,  find  the  nikyUinftloiiic  ester  oxtratltd 
with  ether.  The  oihereol  solution  ia  xlried  oTer  cjilcium  oliltjride, 
tlie  etherdislilled  off,  and  the  reaidoe  puri6ed  by  fraotionation. 

If  it  J!)  deiiired  lo  Introduce  rwoHlltyl-grnnpsorijihcrgrtiups, lliLitft 
&ccoinpllsb<^d  by  emplnyltiglwo  equivalents  of  ftodiiitn  ethoxldo.  und 
two  graminoiuoleculiM  of  iiii  nlkjl  iotlide.  When  two  {)iffr:ri'nt  groups 
are  to  bu  uiibitliluiod,  ono  of  tliom  \t  lirsi  inlnxluced  into  the  mnlecnlc, 
and  on  auUsBqueut  trcHtmcnt  vtiih  asecond  granitnc-aiolecul*  of  sodium 
ethoiidu  and  of  alkyl  iodide,  ibedialkyl-tnaloaio  estei'  ia  produced. 
In  bntb  llieae  casea,  the  romaiader  at  iho  process  ia  identical  with  that 
described  above. 


BncoiQio  Acid,  COOH.CH.CH^COOH. 


167.  Succinic  acid  \%  a  crygtallioc  Bubstanco,  molting  at  18 
luid  diBSoIving  with  rfiftiniltj  in  cold  water.  U  U  preaent  in 
amher,  in  foiuiliict'f]  wtiat],  inid  in  many  plants,  and  c&n  be  syn- 
theticHlly  prupiircd  hy  tlir  following  mnthoda. 

1.  From  Rthylrni^  hromideby  treatment  with  iiotiusaiiim  cyanide, 
■which  convcrta  it  into  ethyltno  cyanide,   ('N-UI3,-Cil,-CN;  on 
,pon ideation,  this  yields  anccinio  acid. 


J 


svccifJic  j4cm. 


>9S 


2.  From  malonic  acid  by  treating  nioooeodiomalonic  ester  with 
monoohloroacetic  eeter: 


=  NnCl  +  (C0OC,li;>.('HCIl,COO0.H^ 

In  thLt  reaction  an  eater  of  rihanetricarboxylic  acid  is  formed; 
when  hvutui]  uborn  it«  molting- point,  the  acid  correapontliug  t4 
this  loeoB  CO, .  jioldin^  succioio  acid: 

CU,U0OH      CH.COOH 
lUUoiHCU-COOH  "^CH.-COOH* 

8iAatUtit»l  miccinfe  acids  ata  be  obtninwl  fii  tho  sxme  way.  On 
the  Diic  liautl,  Btnrtin^  Dot  from  lualonif  cftter  iUvK,  but  rmin  a  mouo- 
ulkj'lniiiloiiio  eftter,  and  on  the  oihVT,  Iroui  an  (i-hulogvii-subeUtiitHd 
estor,  <\Un4'i-CUCl-COOCiH>,S7tain&trioaldkllcyl-4UOctDic  acids  arc 
obtained  : 

/■OOC'.B.  /CE,                               cooc,u,/cn, 
CH,-<'^[N»  +  BrIOlI  =  NaBr  +  CH,*0 CH      . 

^cooc.iij  \cooc,n,  cooc^,  \cooc,H, 


g-Bmninpm- 


CK)OH  CH, 
SaponiSutjon  jiMs   ClIiC OH 

[SO^U     COOH 


;  and  finally,  splitting  off 


COa  gires  symmetrical  dimcthjUacciDio  acid. 


CH.-CHOOOH 


CH,.CH-COOW 

Unsymtnetrical  sub8titut«d  sueoinic  acid*,  in  which  the  hydrogen 

atoms  of  only  onometliyieno-groDp  have  beoiirr-iiW-wI.  ciin  be  obiBined 

in  aa  ao&loncous  manner    The  follovriiiit  e<iiiatiQDa  indicale  tho  method 

for  the  pTftparaiioTi  of  unsyui metrical  dlmetbylsuocinie  add: 

lOOOC,nft),Cn|Na  -H  Brl.O^OOCHj  = 

■-Brom  o  iBubuly  rlc 
wMr 

s  NaBr  +  (COOC,H0,CH  0^Co6cH,;-» 

COOU  Cn,  CH, 

'  6h 6-COOH  -*  OOOH-CUr-C— COOH 

cddlHt^H,  in. 

Succinic  acid,  and  urmmntTica]  nubiitituted  aucvinio  acidn,  can 
also  be  obtaiodd  hy  the  itdiou  of  nn  ctihtinxi]  solution  of  iodine  or 


19^ 


ORGANIC  CHEUJSTRY. 


bromine  upoD  moDoeodiomalonic  ost«T,  or  its  monoalk;l'deriTa>* 
tivw: 

OOOC,H, CO0C,H.         COOC.H,    COOC'.U, 

A-CjXa        +1,+Mtt|6-A'         =A-0 CA'         +SN«L 

C'OOC^,  COOC,H,    ,     COOC.H,   COOC.H^ 

By  sapnnififation,  and  elimination  of  CO,i  the  ester  formed  iB  ooq* 
Tertvd  into  tlio  dt-'^irod  vum pound: 

Glnurie  Acid,  COOH  •  CH,  ■  CH,  •  CH,*  COOH. 

lei.  Glutftric  ikt-td  CAD  tM  sytitht?«i»Hl  by  a  metliod  whicti  rurnishes 
AD  cxtiiupio  «f  another  ty]ie  cf  mnlotiio  ostcr  )iynth<-4is.  It  i<  ebtAiaed 
by  the  action  of  (womoI»c'iil«a  of  uioiioafxltomftiuuicMteronone  mol«- 
«alft  of  inotliyl«n«  iodtdo,  snponiticAtion  of  th«  prod oot,  nod  kpliitins 
off  2C0, : 


I.     (CO0C,H,),cn|S«jM|-CH,.ir£NajCn((:00C,H,)i  = 
=  (OOOC,n.).CHCH,CH((JCK)Cai,),. 


n.  COOH    tx)ou 
Oh  cH.Oa     - 

ICOOIH    lUOOlH 


CH.-tXJOH 

Oh, 

CH.-OOOH. 


B;  nsing  ethylene  brutnide,  or  lriinotlijlen«  bromide,  iiutMd  of 
metlijlene  iodide,  the  two  malosic-ftcid  reeiduea  can  be  Joined  lo- 
gather  in  an  analogous  manner  ihrough  a  ohain  of  two  or  lliroo 
mothjrleue-groupii,  and  the  higher  ww'-dioarboxylic  actds  obtftiiied  by 
spUttiDg  oD  3CO.. 


Slectro-syothetiB  of  Dibasic  and  Otiitr  Acids. 

Wlien  the  aqnooux  »olutioQ  of  an  e&l«T-salt  of  a  dibaaic  acid  is 
«lectrol;zGd,  tbe  metallic  ion  go««  to  ihe  cathodo,  the  anion  to  the 
anodo; 

Anion  CWIoD 


C,H,0OC.C:i[,.COO    K 

■"oiuBiuni  ptbrl- 
niftlooMe 


ELHCTRO-SYSTHESIS  OF  DiB^SIC  AUD  OTHF.ft  MUDS.      t97 

This  anion,  liow«vvr,  is  not  8taM«:  afti>r  being  lUitdiargod  at  tho 
anodo.  it  decomposes  into  oarbon  dioxide  aad  <.',tijOU0*CU,— , 
ond  two  of  tliuib,'  rRnidiK<B  unitu  to  form  Baooiiiic  ester; 

C',H,0OCCH,-Cn,-C00C.II,. 

Hy  this  method,  it  ik  powuble  to  iij'nthesiao  thu  higher  dibodo 
aeiii  froin  tli<>  lower. 

HorKK  haa  dpvisstl  »  very  miitaMn  ap]i:knun.4  (Pig.  3Z)  for 
tlii^  rtrctro-stfniktMs.  It  conitista  of  two  ^Iiihs  niiMi.-K  which  can  be 
joined  at  CO,  tlntir  i-ontonts  buin^r  ecpunitud  at  thin  point  b;  a 
sbwtof  piirchiui?iit-ptti»cr.  _  B  is  purtiftlly  fiUod  withi*  eontfiit™te<i 
aolntion  of  the  ester-^iiH,  invi  A  with  a  solution  of  potasfeiiim  car- 
bonate, 8ini.*e  it  is  only  at  tho  nnodo  that  the  dosiroil  aution  talccs 
pine*.  Tlio  ga««  evolved  can  escape  thrmigh  E  and  /",  wliirh 
serve  nt  thy  same  lime  for  the  introdnctimi  of  the  eloclrinled.  Tho 
tap'fuQuel    Q   contuias  more  of  the  soltitiou  of  the   oatorwt&lt. 


FlO.  $3. — IIoFBR'B   AHPARATTfl  POtt  Et-BCTBO-SrSTOKSIB. 

Doring  the  olectrwlvsia  tho  tup  is  opciiflil,  which  o«uev<a  tho  win- 
tinii  to  uireulHtc  slorly  through  the  iippamtns,  I<n'iil  weeondaiy 
accionn  at  the  anode  being  thim  svciiiiml.  Wlioii  //  iii  full,  its  con- 
tents ore  pmired  back  into  the  tu[)-iuniiel.  To  prevent  rise  of 
toiQperutnre  in  I  In-  noliition,  due  Id  the  iicbion  of  tlie  flwtrie  nur- 
rcnt,  the  whok-  ttpituratns  la  pluoed  iu  water.     It  will  )>e  idMKirred 


198 


ORGANIC  CHEM/Sr/tY. 


from  the  fignre  thai  the  anode  is  very  email.  This  is  to  obtdn  b|i 
it  a  high  density  of  tfie  tiectric  currait;  that  is,  the  quantity  of  elec- 
tricity (lUup&rt'B)  which  Itwivos  ihe  tlectrode  per  unit  of  sarfnco. 
At  th«  quantity  of  amous  discharged  »t  the  anode  is  proportionul 
to  the  number  of  amp^ree  of  the  curreut,  it  h  dear  that  a  hiirh 
douelty  of  current  cuusett  a  great  many  discharged  auioos  to  be 
prt-istiiit  lib  the  auodv,  this  being  uioet  favourable  for  their  inter- 
action. 

ThU  syntheeix  of  dibasic  acids  is  an  extcnnon  of  an  electro- 
eynthedg  carried  nut  long  ago  by  Koi.»e.  lie  showed  that,  on 
electrolysis,  a  solution  of  potanium  acetate  yields  ethane: 


K 


CH,  ICOO      K 


cn,  |coo 


CH. 
CH. 


Anioa 


Ottlon 


Bendes  this  extoneion.  many  others  are  known,  of  which  one  may 
be  mentioned  here. 

A  mixtnre  of  a  ealt  of  a  menotuisic  fatty  acid  and  of  an  ester- 
satt  gives,  at  the  anode,  the  e«tcr  of  a  monobasic  acid: 


cn. 


•  COOlK  +  KiOOClCU,  Cll/CCOO.n^ 

lam  acBUU  PoUwuiii  rlUfl  «iKVIrjiit<p 


-*  CH,-CU,CU,C0OC,H,. 

KUvl  hntjrnM 

Formatioa  of  Anbydridea 

189.  Oxalic  Knd  maloiiie  ocide  do  not  yield  anhydrides,  while 
succinic  fit;id,  (',11,0,.  and  glutaric  acid,  CjII,0,,  can  he  made  to 
do  flo  very  readily.  The  foniiatiou  of  anhydride  is  doe  to  the 
splitting-off  of  one  molei-ule  of  water  from  one  molecule  of  the 
dibaaic  acid,  this  being  proved  by  a  determination  of  the  moleoular 
weights  of  the  anl)ydndf»: 

cn,— tooiii  CH,— CO, 


cn.-co|oH 

/CH,—  COOIH 

6h,  .-J     -H,0 

\dn,-{;ooH 


,0    =    P   -\o 

9iKCI  nlc  ftnhrdrUo 

\CH,— CO/ 


These  anhydrides  are  rapidly  reconverted  into  the  correaponditig 
dibuiiic  acidft  by  disaohiiig  them  in  water. 


* 


CLOSED-OiASN  COMPOUNDS. 


i<>9 


CH,.CO 
A  derivative  of  aucciaic  add,  suc^axmidt,  l  >N'II,  cod* 

tll/CO 

toine  a  rrloftt-d  ohatti  with  four  rarbou  atoms  anil  one  nitrogen  atom; 

it  is  formoil  by  the  rapid  ilii^t illation  nf  ammonium  suooinato.    The 

Btoras  iritiiated  at  the  oxtr'emitics^of  u  oiirbon  chain  contAiiiiti;^  four 

ur   Gve   C-atonu    rtiatrt  ver}'  readily  with  one  another;  tlioKC  in 

iffaurtor  chains  onljf  react  with  difliriilty,  or  not  at  all.     Aoalogons 

phuDomcna  wero  alluded    to    in  connection    with    the  »plitting- 

ofl  of  one  molecult!  of  water  from  the  iuij>'-glycolH  (166),  and  the 

elimination  of  ammonia  from  iva>'-diAiiiiuc»  (182).     In  both  these 

instances    the  Bplitting-off  ia  very  easily  effocted  from  a  carbon 

chain  of  four  ur  five  C-atoius,  but  is  not  jjo^eibte,  or  k-tidii  to  the 

formation  of  very  unatabla  compounde.  when  the  chiiiu  id  shorter. 

It  will  be  ut^ce^ary  later  to  refer  to  other  e^tamjilt-ti  of  the  same 

plienomeiiou,  of  which  a  Batisfactory  explanation  may  be  arrivvJ 

at  by  a  conaideration  of  the  direction  of  the  bonds  in  Kpaue.     It 

iroi  asramed  (53)  that  the  four  atHnitieB  of  the  carbon  atom  arc  so 

directed  that  they  may  be  resided  aa  lying  tuwardm  the  angles  of 

a  regular  tittrahedron,  of  which  the  carbon  atom  i»  the  eeutre. 

In  tho  case  of  a  Htngle   bond  bctwei-u  two  carbon  atoms,  it  \a 

assumed  that  oiiu  afliuity  of  eauh  of  these  atonu  is  linked  to  one 

affinity  of  tho  other  (Fi^.  33,  p.  SOO).     The  position  in  apace  of 

the  C'-at^ine  in  a  chain  of  three  or  more  members,  and  tho  diroc- 

tion  of  their  nftinitics,  are  represented  in  the  ligiire. 

U  will  be  wen  from  this  that  ia  a  uoruiul  chain  of  four 
C^tom^  the  afflniliee  eitnntcd  at  the  extremities  approach  one 
another  clowly,  and  in  a  chain  of  five  C-atomx  they  approach  still 
more  elouolj,  bo  that  they  are  able  Xn  enter  into  reaction  with  one 
another. 

A  fe«'  instances  of  comfHiundn  with  u  closed  chain  oontaining 

cii,cn„ 

only  two  C-atoms,  auoh  as  ethylene  oxide,     \V         art«  known. 

The  figure  shows  tlkat  the  direction  of  the  aflTmitiea  mast  nndorgo 
a  conriderahle  change  to  render  possible  the  closing  of  the  tihain. 
Experience  shovH  thai  compounds  of  this  kind  arc  uustjiblv,  the 
cltMed  chain  being  very  wutiXy  converted  iuio  au  open  one,  us  is  in- 
dicated by  the  "  touuoQ  theory  "  of  BxavEa  (189). 


200 


ORGANIC  CHEMISTRY. 


V- 


Fig.  S3. — Spacial  Rephbsentation  of  thk  Bonus  bktwbbn  3-Q 

C-ATOMB. 

Saponification  of  the  EBten  of  the  Dibaiio  Aoidi. 

It  was  stHted  (169)  thnt  the  esters  of  a  polfbydrio  alcohol  are 
saponifiud  in  stages,  tristearia,  for  instance,  yielding  firat  distearin 
and  then  monostearin.  The  sapocification  of  the  esters  of  the  poly- 
baatc  acids  takes  place  similarly;  thus,  ethyl  succinate  decomposes  as 
follows : 

I.  C,H.(COOC,H,),  +  2NaOH    =    (',H,<^'gg2*jj +C,HjOH  +  NaOH. 

II.  <^.H.  <C00CH  +'^*0H  =   C,H,{COONa),+C,H,OH. 

In  this  reaction  the  acid  ester-salt  is  first  formed,  and  is  atterwarda 
converted  into  succinic  acid.  Reichrr  has  shown  that  the  Telocitj 
constant  (101)  for  the  aapoiiiflcation  of  ethyl  succinate  by  oaiutic  soda 
has  a  different  value  at  different  stages  of  the  reaction,  being  less  at 


J 


FVMAMC  AHD  MAUiC  AODS. 


sot 


l\' 


tbo  ODCl  tluia  At  tlie  boffiniiiiij;,  Tttg  nnotion  al  flnt  takes  pla 
ROCordiDK  to  thn  Qnt  equation,  and  finally  acoordiiig  to  the  second  ; 
tbis  affords  a  sstlsfaolory  explanation  of  tho  rarying  valuo  of  th« 
telooity  gonataiil. 

IL  DKBATIIB&TED  DIBACIC  ACnn. 

Fnmaric  and  Maleic  Aeida,  C^H^O,. 

170.  The  mo«l  important  mumlx.TM  of  the  group  of  UQsatnmted 
uibtieic  ac'vie  iiru  fitinaric  acid  aud  mideic  arid,  i>()th  of  whicli 
have  tbo  formula  C^U^O^.  They  huvo  boon  madu  the  subject 
of  immcrotiK  inTeetigntJons,  a  c<irDplct«  cxpliinatioit  of  their 
i«oin<Ti«im  hiiving  been  finaUy  arrired  at  by  »n  applicatiou  of  the 
principles  of  stcreoisomerinm. 

Fnmaric  acid  is  somewhat  widely  diatributed  in  the  regetaWe 
kingdom.  It  does  not  melt  at  the  ordinary  preesure,  but  ftob- 
limes  at  about  :iiM>°;  it  difiMlvee  with  difficalty  in  water.  Maloic 
acid  is  not  (onnd  in  natnrc;  it  taelts  at  130^  and  is  very  readily 
soluble  tn  water. 

Both  acids  can  he  obtaiuBd  by  h«atiug  malic  acid, 
COOK. CllOU-Cli,  ■  COOK, 
^  the  purticuhu- one  formed  betriE  dependent  on  the  way  in  which 
tbo  heating  is  effected.  Fiimnrio  acid  is  the  principal  product 
when  the  tcmpenitnrc  i«  maintained  at  1-10^-l.SO  '  for  n  long  time, 
but  when  n  higher  tflmppnitnre  i«  employed,  and  the  heating  is 
(jtiiolfly  cnrrietl  out,  the  anhydride  of  maleic  acid  distils  over  along 
with  water.  This  anhydride  i^uirily  takes  up  water,  regenerating 
the  acid.  This  ih  the  ordinary  mothud  for  the  prf^pumtioTi  of  the»e 
acids,  and  it  indicatoe  that  both  have  the  same  ^ructurul  formula: 

cooHcncncoon-11,0  =  coouchick-cooh 


ou  u 


This  view  of  their  constitution  is  supported  by  the  fact  that  both 
scida  yield  Bucciuic  acid  on  t^atment  with  snttium  amalgam  and 
water,  monobromosiicciuio  acid  by  addition  of  HBr,  and  qialtc  acid 
by  heating  with  wattir  at  a  high  temperataro.  Both  acids  have 
therefore  the  same  constitnttomtl  formula, 

OOOHCH;CH-OOOH. 
Similar  isomerism  of  the  rrotonic  acids  (143)  has  been  msn- 
tioncd.      We   shall   now  coiisidor    how   this    isomerism    can   b© 
explained  by  the  aid  of  stereochemistry. 


aoi 


t^GAMC  CHBMlSTKr. 


Tt  WIS  ittatfti!  in  169  that  a  single  bond  between  two  carbon 
atoUL"  nmy  be  rojireeented  ita  in  Fig.  34.     If  the  t*tnihedra  are 


H 
Fm.  81  PiD.  36. 

SniatJI  BOMD  HKTWBKX  TWO  CJABOX  ATOIM. 

dnwn  in  full.  thf'Q  the  single  bond  will  be  «s  repreeeoted  in 
Pig.  35.  Snpposiu};  the  tetrabedra  aiv  free  to  rotate  round  tbcir 
c»mmon  Rxis,  isanterism  oannot  be  expected  for  cotnpotinds 
Colc-Cd^,  nor  hju  it  erer  btfm  obmrred. 


or 


QftATBic  Staoal  ltsrmBHXT*ncis  or 


WbiB  •  Aovbl*  bond  is  praanit,  then  two 

S«.  37^  and  S«.      Ftae  Nttttipa  i<  Ika 
OBe  fcnotWr  ittlMO  b 


fUMARrc  AND  MALElC  ACIDS. 

Ft  \e  seen  from  the  foregoing  figures  tliat  (UffereucM  of  group- 
ing  depends  on  thf  position  of  ilie  groups  a  and  b  of  out*  lutniltcd- 
ron  iritli  refereooeto  the  similar  grouptt  a  and  b  of  the  other.  In 
one  case,  a  may  hn  over  n,  and  b  ovlt  />,  wliich  iti  the  grouping' 
in  Fig.  37  ;  aud  in  the  other,  n  may  bo  ovor  b,  and  h  over  a,  as  in 
[Tig.  3lj.     This  can  be  represeuied  by  the  tonuul^ 

and  tl 

b—V—a 

i,  the  two  urotouiu  acidg  wouhl  be 

CH,— *;— H  n_{  _cii^ 

II  and  .1 

H— C-— (  OOI I  H— <■— COOH, 

[and  iumaric  aud  maloic  &k\A*  would  have  thi;  formulm 

COOH— t— It  H— C— COOH 

1  ii  and    n.  11 

H— (— toorr  II— c— coou 

Trim*  Cla 

Ft  must  now  be  provinl  which  of  these  two  formuliK  belongs  t*'' 

■fumuriu  ucid,  aud  which  to  m&leic  aoid. 
Uftlelc  aoid  yields  an  anhydride,  wliilo  famnric  ncid  doOii  not 
dn  so.  It  wit)  be  noticed  tliat  in  forniulu  11  the  C!iirbnxy]-groupa 
are  in  jnxtapoaitiun  tu  oiiu  anolhtT.  but  in  furmtilu  I  they  are  as 
far  rt;moVL-d  front  cuch  other  00  posdiblu.  Only  in  the  acid  having 
the  m-formuU  uru  thu  carboxyl-grou p8  ruprctt«nt«d  in  upoaition 
^to  roMt  readily  with  one  another: 

H— t.— COO  jH  H_(:_co 

II  r^        ~*  II       >0, 

H—C— colon  H— C— CO 

Halelc  at  111  lUJsIc  Mbjninde 

from  which  it  is  assuinvd  that  fumaric  acid  han  Ihe  cotuli/uWon 
in<licatc<t  in/ortiitilii  I.  nitd  ttiit/e'i^  acid  ihat  \n  for*nula.\\- 

Further  (Miuiiideruliun  will  ghow  thai  thU  ulau  iiecounts  for  the 
'Other  known  propertieti  of  these  aeidH.  It  should  be  observiKl  that 
Dpither  formula  contains  au  asymmetric  C-alum,  ho  Ihnt  iieitht-r 
optical  activity  nor  thu  great  rcaemblunce  iu  such  properti^  as 
tpociBc  gnivilT,  meUing-]>oint,  solubility,  eto.^  due  to  the  simi- 


I 


I04 


ORGANIC  CHEMSSTRY. 


Inrity  in  internal  structure  charucterJetio  of  tbo  iwii]vrii<m  occa- 
sione*!  by  nu  attyminelric  carbon  atom,  ia  to  be  expected.  Famario 
and  laalcit;  aeida  do,  io  fact,  display  great  dillereuces  io  these 
physical  proiii-rtieB. 

Both  ftiRiaric  acid  and  malelo  acid  combitio  witli  bromine,  bat 
the  dibromo-JidditioM-productB  thus  obtainipd  arc  different.  Fmnaric 


110  CO 


HO-CO 


+  aBt^ 


CO'OH 

FiQ.  39.— FuMAHic  Acid. 

p  CO'OH  . 


Flo.  40.— UiBROUOsocaxic  Acio. 

^  '^^^  coon 


+  SBr 


CO-OH 


Fie.  41.— MaleIc  Acid. 


CO'OH 


Fie.  id  — IdoDiBRoitesvccuttc  Acid. 


ncid  yields  dibnmMuceinie  acid,  Boloble  with  difficulty  iu  woler;  and 
maleic  ut-id  yaQdibrmHOsuccinic  and,  much  more  reudily  soluble 
in  water.  A  cousideratiun  ut  Pigs.  3D  to  43  will  show  tliiii  dilTercnt 
acids  must  rvaiitt  from  tlii^  reaction.  Figs.  40  and  4'^.  repreaeoting 
dibromoauccinio  acid  and  laodibromoancciDic  arid  reejiec  lively, 
caanol  be  made  to  coincide  by  rotation;  this  ia  soon  more  clearly 
from  a  ootnpariHon  of  Fige.  42  and  43.    The  latter  mny  be  obtained 


FUMARSC  AND  MALEtC  ACIDS. 


"5 


from  Fig.  40  bj  rotstion  vl  the  upper  telrahedrou  ronnd  the  ver- 
tical mis,  the  position  of  the  lower  t«tnihc>drou  remaining 
n&altorod.  It  wUl  be  obeerred  from  the  figures  that  the  order  of 
the  groupe  linked  to  both  oarbou  atoms  of  the  ifio-^cida  is  11.  Br, 
coon  from  left  lo  riglit,  und  alao  for  the  lower  earbon  atom,  of 


CO-OH 


— tmr  = 


CO.0H 
Tio.  43. — DtniioMUBvetijcic  Acid. 


ocKm 


COOE 


Vtti.  44.— KkomomaijiTc  ACIO. 


HO<X) 


— HBr  = 


CO-OH 


CO-OH 


7ie.  45.— IsooLsaoiiaacQCiMC  Atiu.    Fia.  -(4. — BuouuFBUUtio  Acuh 

ibc  other  acid  (Fig.  40),  but  for  the  upper  carbon  atom  it  ia  from 
right  to  left. 

When  nBr  is  removed  from  dihromoMacciuic  acid  (Fig.  43),  th« 
il-atum  linked  to  oiiu  utrbou  atom,  and  tlie  llr-atom  linked  to  the 
other,  are  eUminaLud,  ^iekliug  an  auid  COOII-CH:  CBr-COOH.  ' 
Thia  rtmoval  of  llBr  could  not  bu  effected  if  the  tetrahedra  were 
in  the  position  shown  in  Fig.  4U;  rotation  round  the  vBrlieal  asi£ 


7ttCAmC  CHEMISTRY. 


must  first  take  place,  ao  aa  to  bring  11  and  Br  into  "  oorreKponrt- 
ing  "  po8ition8,  ag  iu  Fig.  43,  when  aplitti  iig  off  U  Br  produce  the 
acid  rrpree«ated  in  Fig.  44.  This  nctti  eiuily  vieltis  au  »uliydride. 
since  the  COOII-^oupH  are  in  bhe  oorreeponding  ptMitiona;  it  is 
therefore  brommialelc  acid. 

When  IT  Br  i^  split  ofrM>m  iM>dibromo8iiccinic  aoid,  reprewnted 
in  Fig.  4.'>  (which  may  be  obtained  from  Fig.  43  by  rotation  Iu  tho 
same  way  as  Fig.  43  from  Fig.  W),  an  acid  is  obtaiiied  which 
Ottnnot  yield  a  corresponding  anhydride,  but  is  oonverted  by 
removttl  of  water  into  the  anhydride  of  bromomaleic  acid.  This 
behaviour  re^tE-mbleH  that  of  fuuiario  acid,  whii;h,  under  the  same 
coudilious.  yielilB  malmc  aubytlride.  This  acid  luuit  therefore  be 
broniofiimaric  arid  (Fig.  46). 

U  will  W  MM-D  from  thi'  foregoing  that  tho  conBtitotion  aeeumed 
for  these  acide  on  etereochcuiical  ground*  does  account  for  their 
chomicfd  properties.  Another  example  will  bo  mentioned  later 
(18S),  wliirh  altto  HUpports  the  explanHtton  juHl  given. 

Mateic  acid  can  be  converted  into  fumuriu  acid  in  several  ways: 
by  keeping  it  for  Bnmu  time  nt  a  tom[wnilure  above  its  moltiiig- 
point ;  by  bringing  it  into  contact  with  hydrogen  halides  at  orUiiuiry 
tcmperatuTce;  by  exposing  n  conceutrated  eolutiou  of  molclo  acid 
in  preeence  of  a  tnu^e  of  bromine  to  the  action  of  >iiinlight,  a 
ronctioQ  which  tnkex  pbice  only  slowly  in  abBcnc^e  of  light;  hv 
trealiiig  the  ethyl  e»tpr  uf  malei'c  acid  with  small  qtiantitipA  of 
iodine;  or  in  other  ways.  The  ease  with  which  nil  these  deoom- 
poHitions  take  place  »howH  that  ntaluTc  acid  \»  tho  uiietable,  and 
fumaric  acid  the  etablo,  modification.  InvcrBely,  fumaric  acid  is 
converted  by  dii^tillation  into  maleie  anhydride.  Tho  mechaiusm. 
of  thti»u  ruactiouB  is  not  fiiUy  understood. 

The  taal  rcfiction,  m  well  aa  that  by  which  malvlo  acid  is  con- 
verted into  fuiDario  aciil  by  the  action  of  lioat  alone,  may  bo  explained 
by  llm  uusii  nipt  ion  Ibat  an  cxcliaiigo  of  hydrogen  aad  carboxyl  takeft 
plam  at  one  of  the  doubly-linked  C-atoDos: 

H— C— COOU  H— (>-CO0H 

II  ->  II  . 

H— t%-<LX)OH  tlOOO— 0— H 

Afletylenediearboxylic  Acid,  COon-CsC>OO0H. 
ITl.  AetJi/iin»1iearlKxriiIic  arid,  the  sitDplosl  type  of  dibaaia  adda 
onalaining  n  triple  bond  in  the  molooule,  ia  pniparod  by  the  action  of 


DIBASIC  ACiDS. 


ao7 


alooliolicpoUuti  on  ilihromosuccinlc  iicid,  COOH-CHBr-CHBr-COOII. 
A  in«tbod  of  (oriaatioit  indicnliug  its  conaUtulioR.  The  aiLvor  stilt  of 
acei]'leu^(llcArliii>:yli<i  ai'iJ  remlil}-  splits  oS  two  moleoulos  of  uarboii 
dioxiiJc.  KtUi  p'roduclioi)  of  8)1  Tcr  aoetjlene  : 

fro;iAg.(=C-ir(:^lAg  =  2C0,  +  AgC«CAg. 
Acel>-leuedicarbox}'lic  aci^I  melis  tit  17.'i'',  mid  yields  a  b«ituliriil, 
«7»uUlin«  acid  potassium  oalt,  which  ii  soluble  with  difficulty  io 
water. 


AfRnity  Conttantt  of  the  TTnBiitiiratttd  Acids. 
172.  Likp  liio  moiiobaeij^  iir saturated  acide  (141),  the  dibMJc 
nnMtiirntvd  ticid»  hnvc  grmtcir  ulBnity  (.'ongtuiits  ttutn  tlie  corn^- 
tponding  twtiirated  ari^s.  For  siicfiiiie  iiciil.  /'=  O-OOrjfi.'i,  xnci 
for  fimiHric  ai;itl,  K  =  C>.()'.i^.  Tht*  strengtli  of  acetyleiiwHcur- 
boxriir  acid  ie  about  etjiial  to  that  of  sulphiirio  ncid.  ThiiH.  the 
prvseiioe  of  a  double  bond,  and  ^vcii  more  of  a  triple  boud,  iutcn- 
ti&es  the  acidic  diameter,  for  muleic  acid  K  =  i-l7,  or  about 
tw1r«  timue  as  oiti«li  a&  for  fiinmric  acid.  Tbis  ehovx  the  great 
in(lu*ueo  whicli  tht-  diatiiiice  betwepn  tho  cftrboxyl-groups  in  the 
molecule  exerciees  upon  the  girength  of  those  acide. 

17a.  Bakter  lia-s  prepared  dihasic  acids  combining  rooro  than  on* 
triple  bond  in  the  moloaiite  from  acetylenediuarljoxylic  aotd,  Wlieii 
hfHU'd  wllti  witter,  lia  aoid  poinMinm  salt  Is  convvrtod  tuto  ihv  potas- 
stuiD  suit  of  praplolt4!  aciil  (MB),  with  low  of  COi! 

KOOC-C«C-iC<>;iH  =  CO,  +  KOOr-C'»CU. 

When  thfloof^por  derivHtiv«  of  this  sah,  KO^X^CsCc■).  istrmted  wjth 
poiassiam  fffrricyanidft  in  alkaline  Aoluiion.  CuO  is  formed,  wbilo  tli« 
two  acid-rcsldiiPR  imiie  at  ilic  ^.aRie  time,  wiili  jiroduotjon  of  the  potas- 
sinm  salt  \>t  tiiatxtyhiir'linirhojrylic  ircitl.  KOOC-C-C— C'=C:0(M)K. 
Tlio  acid  poia«8iuiu  ink  o(  thia  aaiil  bIbo  loKesCO*  easily,  and  the  eop* 
per  derivatirA  of  Ihe  inoiiobiisio  acid  ihua  formed  is  converted  by 
stiiiilar  oxidatioi]  IdIo  CuO  Mod  the  |Mitiusiiim  suit  of  tUra-ttcttgi&n»- 
dkarliwriilic  acid: 

SKOOt;C*C-CHCcu-.K{XK;C=C  C  =  C'CsCC=0-0OOK. 

Theso  couiiMmnds  arc  very  unstable,  boiiig  decoiopowd  by  Che  action 
of  light,  and  in  other  waya. 

m.     FOLTBASIC    &CIDB, 

17«l.  Acids  coutaintnp  three  carboxyl-firtnips  in  union  with  one 
carbon  utonr  are  not  kaowu,  cxcu^it  in  the  form  of  estfrs,     Th« 


aotf 


ORGANIC  CHEMISTRY. 


Iriethyl  ester  of  vietltatuiricnrboxglic  acid  is  obtained  fay  the  action 
of  chloroearbonic  oeter  (849)  on  sodiomolonic  cater: 


r,n,ooc  c)  +  Xi»|CH(C0OC,nj,  =  c,e,ooc  ■  (■n(cooc,H4), 


t'liloicc'nrlMiulc 


When  tliut  ei(t[>r  \»  Aapunilied,  CO,  is  split  off  at  tlie  same  timt!, 
mutoiiic  ucid  beiug  fornicd  iiiaiwid  of  the  oorrvxjioudin^  irilxwic 
acid.  Tiiia  ia  aiiotlicr  iustmitv  of  thi?  phcuomunoii  tUsl  untral 
nttfalive  ffi-oiifS  do  not  rvtuuin  in  union  with  one  cart/on  atom,  two 
being  the  maximnm  number  in  the  caac  of  ciirboxyl. 

A  detirrtption  ol  the  »)'ntheflos  of  a  few  of  the  polyhnsir  noids 
will  afTonl  exiimplcs  of  the  methods  adopted  for  the  prepunitioD 
of  compouiulM  of  thta  c\as». 

Tribasic  AoiiU. 

175.  A  type  ot  the  tribaeic  acids  is  aaaai'-propanetricarbifxylic 
^«eid,  or  tricarbftllylio  acid,  which  can  bo  obtained  in  several  vava. 
],   From  tribromhydrin  by  treatment  v'ith  pntaeeium  c>'unide, 
and  eapoiiiUcjition  of  the  tricyaubydrin  thus  fonnod: 

Cllr-CU— til,   CH,— CU— tU,   ClI, — CH CU, 

6r   Ki-   Ur   "*  CN   CN  Cn  ~*  OOOH  COOH  OOOH 

3.  From  maloiiic  ester  and  mouocliluro&c«tic  oster: 
(C,H.QOCJ,ClKi;-f  2Cl|CH,  •  CO0C,Hj  = 

On  saponiflcation  of  this  c«ter,  an  nvid  is  nbtninod  which  on 
litiing  heated  loses  (.'0,,  with  formation  of  tricarbailylic  acid: 


^'"^'     CH,(;OOH 


Cil.'COOH 
tH  -CO OH 
CI!,-COOH 


3.  From  mouoeldurotiurcinit!  (wter  and  malonic  ester: 

CH(Cooc,n,>, 


(CAOOC).CH^a+^|CH-COOC.H.  ^  -f  CH-COOC   I 


31  OIHIvblOTVWlOCtulO 


TfVBjiatC  AND  TETRABAStC  ACIDS. 


tO^ 


'hen  the  eeter  thuiii  obtained  is  sajKiDiGed,  CO,  i(t  split  off,  whli 
'fomiiilion  (if  tririirbiillylic  Acid. 

4.  A  Hyntlic«iFi  peculisr  to  the  |>olyhftaio  acide  L-ouhiittA  in  tho 
^adtli(iun  of  sodioiuulonic  6st«r  lo  the  eeters  of  unsaturated  acids* 
nicb  «A  fumnric  ncid : 


Ka 


at 


(CO0C41A 


NaCHC0OC.H, 
CHCOOC.H,  J 

+  If  *^       CH-COOC.H, 

CU(COOC^J, 


CH-cooe.n, 


SiipoQifi cation,  with  eubeequent  splitting  of  of  CO,,  3nelds  tri- 
rCirbsllrlic  acid.     It  meUe  at  l(iO°,  and  ie  eaeily  eolublo  in  vator. 
Acouitte  aciil,  M.  P.  l!il°,  ie  a  tvjie  of  an  nnsaturntetl  Irihai 
}atiit.     It  is  obiaiceii  from  citric,  uoid    (198)  by  the  ellminatioE 
'  o(   water    by   heating.      The    coiiatltution    of    aconitic   add  is 

CH^=:C CH, 

COOll  OOOH  COOH' 

■inoe  on  reJuctiou  it  ie  ootiverted  into  tricarballylic  acid, 

Xttrabaaio  Acids. 

176.  Some  examples  of  the  synthetit;  methodn  employed  in  the 
preparation  of  the  tetrabaaic  acids  liave  be«n  already  mentioned 
in  Connection  with  the  gyntliMpfi  of  dibauic  and  tribRKio  arids  by 
mvans  of  malonic  ceter.  lu  tlie^-  reactions  the  tetrahimit?  iw'uU 
are  often  formed  as  tutermcdintc  products,  being  converted  by 
Fjililiing  off  one  or  two  molecules  of  carbnu  dioxide  into  tribuaio 

tand   dibaeic  acids   respertively.     This  reaction,  howevfr,  alvroya 
yitldfl  a«dB  containing  two  carboxyl-groupe  in  union  with  one  car- 
l»n  atom.     wafica'-Iifitanetetracarhoxyiic  acid,  in  which  only  oi 
carboxyl-group  \&  linked  to  each  t-arbon  atom,  can  be  obtained  by! 
uplittiug  off  2 CO,  from  a  hesabaaic  acid,  tva^ff^uj'-bvfttHehfracar' 
btttyhc  acid,  wliicli  is  itstdf  obtaintd  by  the  action  of  iodine  on 

Etetricarbozyiic  tfter  (187); 
c.n.oocOiJ.IJ, 
kiiiIlMa*irIc«rt>ox)rlie  ntvr 


CK,.tOOC,l{, 


(C,H»OOC),C|Jfa      Ntt|CtCOOC,HJ, 

in,cooc.n. 


(COOC^J, 


C(CO0C,U,), 
CH.COOC.H. 


310  ORGANIC  CHEMISTRY, 

CH, 0 C CH. 

H.  I  /\  /\  1  - 

COOHiCO.lH     COOH]CO;|H     COOHCOOH 

■■ilSiM'-BuIuirhezBcarboij'lic  *dd 

CH, CH CH CH, 

~*  COOH  COOH  COOH  COOH 

•M^H'-BuUnetemetLrbozf  lie  acid 

Higher  Polybasio  Aoidi. 

177.  The  last  example  shows  how  it  is  possible  to  obtain  higher 
members  of  the  series  of  polybasic  acids.  Iq  general,  the  hydrogen 
atom  in  the  eaters  of  acids  containing  a  carbon  atom  in  union  with 
two  carboxyl-gToups  and  one  hydrogen  atom,  is  replaceable  by 
sodium.  When  a  sodium  compound  of  this  kind  is  treated  with  a 
halogen  derivative  of  a  polybasic  acid,  a  higher  polybasic  acid  is 
formed,  the  same  effect  being  produced  by  means  of  iodine,  which 
causes  the  union  of  two  molecules.  These  reactions  afford  a 
means  of  synthesizing  numerous  polybasic  acids,  the  ester  of  even 
a  14-bB8ic  acid  having  been  thus  obtained. 


SUBSTITUTED  ACIDS. 


■cid, 


III  thet»e  acids  there  is  no  liydrofroD  in 


I.     B&LOOEH  SUBSTirnTSD  ACIDB. 

178.  The  halo^n-siiListitiiUiI  iicrids  ciui  he  obtained  bj  the  direct 
action  of  chlorine  or  of  bromine  upon  the  aatnratod  fatty  aride, 
but  this  prowiw  Ut  tint  von,'  jiatiBfnrtory,  The  monochiopo- 
acide  mid  monobromo-Jinids  mn  he  Iwtter  preparfld  by  the  uetiitiL 
of  chlorine  or  hromine,  not  iipnn  the  acid,  but  upon  ite  chlor* 
ide  or  bromide.  The  prooesa  in  carried  out  by  treating  tlie 
acid  with  phofiphorut!  luid  a  huhigim,  the  phusphoruH  balide  pro- 
duced reacting  with  tho  ncid  to  form  an  ncid  chloride  or  bromide, 
B-COX,  which  i*  then  attacked  by  the  ciccsb  of  halogen  present. 

Some  acids  cnniiot  he  brominated  in  this  way:  for  example, 
trimethylacetic  atrid,    (CII,),C-CO0n,    and    tetramelhylaueclnic 

(cn,\rcoon 
(cnj.ccooH" 

Doion  with  the  a-oarbon  atom,  which  is  directly  Hnked  to 
earboxyl.  As  a  general  rule,  it  is  only  poaiiiblo  to  hroniiTiato  aoiils 
of  which  the  a--cart)on  atom  ih  linked  to  hydrogpn,  the  arids 
formed  being  called  a-bromo-ueidB.  The  constitution  of  these  is 
proved  by  converting  them  into  hydroxy-ncidB  {182>,  which  are 
ehowQ  to  bo  a-compouuda  llirougb  thuir  «yutheei«  by  another 
method. 

HAlog«n-BnbeMtut«d  acids  can  nlno  be  prepared  by  addition  of 
hydrogen  halide  or  halogen  to  the  unsaturated  acids,  or  by  the  action 
of  phoephonis  halides  on  the  hydroxy-acids.  The  iodinated  acids 
cao  aODietimes  be  lulvantngeou-tly  obtained  From  the  corresponding 
chlorinated  derivativcH  by  henting  them  with  potosfiiiim  iodide. 

The  introdnction  of  h&Iogoa  into  the  molecule  caueesa  marked 
inoreaid  Id  the  strength  of  an  uoid,  m  will  be  seen  from  the  table 
OD  Dextpago  of  dtesooiation  constants.  A". 

9It 


ORGMWC  CHEMISTRY. 


KUM. 

rofmnlK. 

K. 

CH,Br.(X),U 

ciicu.ro.H 

CH,CH,-rO,H 
CU,I<il.-CO,H 

0-0018 

O'lU 

O-IW 

0-075 

181 

0'00I34 

O'WOU 

This  tabic  allows  that  the  Ktrcn^h  of  an  acid  is  iucroaaod  to  a 
greater  cxt<'fit  hy  rhiorin*  than  by  bromine.  ntnJ  by  bromine  than 
by  iodine,  iinil  thiit  llio  introduction  tir  nion>  than  onR  chloriue 
atom  occnuons  n  markixl  inorcoM)  in  the  Ktrengtli  of  the  acid.  The 
position  of  thp  Iui1og«n  atom  also  exertii  an  influence;  for  iodoacotie 
acid,  in  which  the  1-atom  occupies  th«  ff-posiiion,  the  value  of  the 
constant  is  3'i  timoe  as  ^re»t  as  that  for  acetic  acid,  while  for 
/J-iodopropionic  acid  K  le  only  7  times  aa  groat  &e  (or  ptopiomc 
acid. 

Tb«  influeiioe  of  the  carbozyl-groiipd  upon  tlte  lialogen  atoms 
te  suoh  that  the  jtrofm-ties  of  the  monohnhgtH-UHbfdtMted  acids 
depend  cltitjtif  ujjoh  the  relative  petition  of  the  lialogen  aloni  and 
the  cttrboxyl-grovp. 

On  boiling  with  alkalie,  the  a-haloffcn-SHtatitated  acids  are 
eaaity  converted  into  the  K-bydroxy-Bcids  by  excliaag<<  of  halogen 
for  hydroxyl: 

cn,ci.coon  +  Kon  ^  kq  +  oh,oh.cook. 

]|«aoehkmMrU«  Mid  PotHMtann  Klrwllua 

Under  the  same  treatment,  the  /9-halogen-«nhRtitntod  acids 
split  off  hydrogen  balidc,  with  formation  of  iiDsatnmted  acids: 

0H,CIIUiCIl,-UO0U  =  CH,UH:CH.C0OH4-HCL 

5<;)i  \omhMft\c  uai  C'ratonie  acM 

The  beliaTJoiir  of  the  /l-halof^ti'Sobelil  utvd  aclila  wUon  treated  with 
sodium  cartx>iiat<>  is  very  characteri-Mic:  wlicn  Ilioy  aru  vanned  with 
an  aqusoua  jtolnttan  of  it,  not  only  Li  liydrogeii  halide  eliminated  from 
the  molecule,  but  C0«  is  split  off  ivt  the  same  tiioe,  with  formatioD  of 
an  nnsaturaled  Iiydrocarboo: 

CH,-CUL'UiCO,lNa  =  CHiClIiCHUU,  +  NaBr  +  GO,. 

Dtitflcne 


HMLOGEN-StJBSTlTl/TED  AODS. 


»t3 


On>>oiling  with  water  or  with  nn  »IkaIi-PHrbonato,the  ^-halogpn- 
euWitutt-tl  iK'i(l.>i  rejMlilv  split  ofT  11 X.  forming  »  jwoulisr  cliiM  of 
cuinpuiiiiib  kiiuwti  IIS  hiclonej'  (183  unU  188) : 


CH,-C11-C1I, 


fH,-CO- 


►CH.-cn-rn,-fH,-co 
I . 6 


VolproUotODB 


Cbloroaoetic  Acidt. 

17».  MonochlormcetU!  acid,  CH,C1-CCK)H,  is  obtained  by  the 
action  of  obloriue  upon  acetic  ncid,  in  presence  of  siiljibur  lu  a 
chlorine-carrier.  It  is  a  cr^-stalliue  soliti,  melting  at  ij3°.  IHchhro- 
actiie  and,  CT!C1,-COOH.  and  incfthroa^edc  acid,  CCI,-C00n, 
are  beat  pre|)ared  from  chloral  (204).  Trichloroacetic  acid  is 
unstable,  uml  is  docompo^cd  on  boUiug  with  water  into  carbon 
dioxide  and  chlorofurm: 

cci,|rg;jn  =  cci,n  f  co,. 

This  19  another  cxiimple  of  the  fact  that  "  loading  '*  a  carbon  atom 
with  negative  clcraonts  and  groups  makes  the  compound  in  which 
it  is  uoDtainod  uuBtnbJc. 


yS-Iodopropionio  Acid,  CH,I-CH,.OOOH. 

180.  /i-IutlvpropioHic  acid  ie  eouietiuioa  iiHod  iu  eyntfaMM,  anil 
is  therefore  of  i>onie  importance.  It  forma  well-deflned  crygtala, 
■lightly  actable  in  cold  water,  and  melting  at  82".  It  is  obtained 
by  addition  of  hydriodic  acid  to  acrylic  acid: 

0H,:CH.C00n  -|-  IH  =  OH,l-0H..COOn. 

As  a  general  rule,  addition  of  hydrogen  halido  to  acids  contain- 
ing a  double  bond  between  the  n-  mid  (i'Cathou  atoms,  denoted 
by  .^•*.  results  in  the  union  of  halogen  with  the  /^-carbon  atom. 
Thi*  constitution  of  /If-ioilopropioQic  acid  in  dediK^od  from  its 
tranftforjuatioD.  into  succinic  acid  in  the  following  way: 

ON|KTT|0H.CH.-COOH^CyCH..CH..COOH-^ 

-.COOH .  on,.  CH, .  COOH. 

SuDuiiUcacid 


214 


ORGANIC   CHEMISTRY. 


Adds  coBteining  more  than  rae  Halogen  AtoB  in  the  Koleeole. 
181.  Isomerism  in  this  type  of  componnds  may  be  occasioned  by 
a  difference  in  position  of  the  halogen  atoms  in  the  molecule.    Addi- 


C»H„i 


Ou^jOOtB 


FiQ.  47.— Ebdcic  Acid. 
TVaiW-fonnalm. 


C|H„< 


H  Br 


Kotsied 


OaH«CO,H 


C,H„ 


Fig.  48.— Dibkohokrocic 
Acid. 


Ou,H,jOO,H 


Fie.  49.— DlBHOMOKUUCIC 
ACtD.  ' 

Each  H-atom  in  comspoDdlDjf 
poBition  to  ft  Br-atom, 


tion  of  halogen  to  an  nnsaturated  acid  results  in  the  formation  of 
a  compound  in  which  the  halogen  atoms  are  linked  to  neighbonr- 
ing  carbon  atoms. 


HALOGEN-SUBSTITUTED  ACID^. 


aiS 


The  Bplittiog  off  of  hydrogen  balide  from  acids  of  this  class  affords 
a  strikiDg  example  of  the  Talae  of  stereochemistry  in  expIainiDg  phe- 
nomena for  which  the  ordioary  oonstitntional  formnle  are  nnable  to 
account.    It  was  mentioned  in  connection  with  the  stereoisomerism 


C»H„ 


-hBr,  = 


^CHtfCO.H 


Fig.  60.— Brabsidic  Aom. 
CU-formula. 


C|Hii 


itiiUted 


----^o^n^<x>t'B.     g 


CuHMOOtS 


FiS.  51,   DiBBOHOBBABBIDIC  ACID.      FiG.  58.— DiBBOlIOBRABSlDIC  ACID. 

One  H-atom  in  oorrespoading  poeitioa 
to  one  Br-atom. 


of  the  unsaturated  adds  that  the  dibromlde  of  one  modifloation 
splits  off  2HBr  very  readily,  yielding  an  acid  with  a  triple  bond,  while 
with  the  dibtomide  of  the  other  modification,  this  either  does  not  tnke 


ai6  ORGANIC   CHEMISTRY. 

pliica  at  nil.  or  «aly  nritb  groat  difflculty.  An  exaniplt;  of  this  is 
ulTonltjd  by  onioio  and  briwaidie  flcida,  which  have  been  proTwl,  by  ibe 
invthod  indicated  iu  146,  to  hnv«  tlio  coiwlitution 

C.H„.CHiCH.C„H„-a>OH. 

On  addition  of  bromine,  and  BDl»cqni(>nt  heating  with  akohotic  potaab 
at  ino'- 170%  dibrumoenicia  ti«id  enslly  lo«es  Sllltr.  yielding  behtnolic 
Of^d,  CiH.i-t'»C'C,,H„.COOII;  whil«  under  the  Bame  Iroalmeut, 
dibruniobniasidic  iiciil  sj>iila  oil  one  inolocule  of  hjilrobromlc  acid, 
with  production  of  a  monobromoenicic  ftCuL  This  dllIer«DC«  is 
accoiiumi  for  by  assi^^ning  tlio  /mnjc-rurniuU  tu  crude,  aud  th«  cU- 
formuU  to  brassidic.  ncid,  as  indicated  in  Figs.  47  to  93. 

In  the  formula  for  dibromoemcic  acid,  the  lotrahedra  may  tie 
rotated  m>  aa  to  bring enoh  Bi--atom  above  a  H-alom  <17(l},  umlcintt  the 
«1in]i[ihtii>n  ot  SHBr  po!t»iblA  (Figs.  48  and  49):  while  in  tlmt  (or 
dibromobrnsi)iili<;  acid,  only  one  8r-atom  and  one  R-aiom  can  he 
brouglii.  iuio  the  ''  correaimndln^  |)osi(iona  "  to  one  another  (Figs.  51 
and  52). 


n.    MonoB&sio  htdboxt-acidb. 

1B2.  The  hydroxy -»<;!(]»  nre  aubstauces  containing  one  or  more 
hydros yl-groiipa  »ml  c»rboxyl-(n"'"ips  in  the  moloiiulo.  Thr 
geuem)  mothods  for  their  formntion  depend  u|voti  tho  introduction 
of  hydro xyl-^on pa  and  «nrl>oxyl-groupg.  TJiey  are  [irotluoed  in 
tho  following  reft(;tioTi». 

1.  By  the  careful  oxidation  of  polyhydrio  ulcohoU: 


CH.CHOH.CH,OH 

FropjrtBoeitljcal 


CH.CHOHCOOH. 

Lauito  aold 


S.  By  replacement  of  the  halogen  in  Imlogen-sutislituted  Rcids 
l^liydroxyl,  aa  alrwidy  deacriliod  (156j. 

3.  By  rt;duction  of  tlic  ftldehydic  at-icls  »nd  kelonic  acida,  which 
contain  both  u  curhoxyJ -group  rtnil  »  carboiiyi -group: 

CH.rorooH  +  211  =  lh,  ciioncooH. 

Pyniraramio  oclil  L>aciic  meiil 

4.  By  tho  action  of  nltrone  acid  upon  acida  coul«i&ing  an 
amido-group  in  tho  iilkyl-residne: 

NH,-CH,COOH  +  UNO,  =  OH,OH.COOH  +  N,  +  H,0. 

QlTQooeU  Olycolllo  acbl 


MONOBASIC  HrDROXY-MCIDS. 


«»7 


S.  By  nddUion  of  Lydrocyauic  ncid  to  aldehydea  or  ketones, 
and  liydrolysu  of  thi>  uitrile  tliuB  ubtaineJ  (110,  3);  thU  method 
yields  only  a-hydroxy •acids: 


y 


\\ 


c.^«*(^?f  +  211.0  =  ( „n.„^,c^oon  +  nh.. 


Cynnliydrlii 


I  Hxlroucykoid 


By  9XoliaiLge  of  Br  for  OU,  acids  which  havu  bi>cn  brominotcd  bj 
the  method  de»oribfd  in  178  )ncld  hy<Iroiy-ftt'id8  ideiitioul  with 
thoto  obtaiii«il  by  this  i-yaiihydritt  synthesis.  It  follows  that  in 
thtse  acids  the  bromine  is  iu  uiiiou  with  the  n--carlHm  atom. 

1.  Oxidation  with  potfteeiiira  permangHUate  efft'cts  tho  directl 
replacement  of  hydrogeu  byliydroxyl  ina«ids  cotitaiuiug  ahydrogcn- 
atom  linked  to  a  tertiarv  carbon  atom: 


^§«>CIICO0H  +  0 


■  Hyilmzyhiotiutyrto  Mid 


Fropertiea. 

183.  Diflerwiit  «om]iouinIa  are  obtained  from  the  hydrosy- 
by  Bubtttitutioii  in  the  hydruxyl-grouji  and  carbo it yl -group.  When ' 
the  n<a(am  of  thu  hydroxyl-^uiip  is  replaced  by  Mllcyl,  an  add 
eth$r  ia  obtained: 


CH.OHCOOH 

airn>lllo  avid 


CH.OI  .Hj.C'OOiJ. 


EllijUljcollU-uld 

Lflco  an  ordinary  etht>r,  C.,H^.,-0-C„Il„„,| ,  ethylglyooUie  add 
(•annot  be  Riponiflod.  When,  on  the  otlier  baud,  the  ll-ntom  of 
the  curboxyl-gruup  ia  oxchungod  for  alkyl,  an  wtcr  is  produced: 

CII.OHCOOH -.CH.Oir-COOO.H,, 

Zifayl  s'ymllnu 

Like  other  cetors,  tboso  compounds  i>aii  bo  saponiflod. 

The  introdaclioi;  of  liv'lru.xyl  dtronKthuna  tho  fatty  acidi  to  an 
extent  dopendont  on  it«  position  relative  to  the  wirboxyl-group,  an 
effect  analof^ons  to  that  jtroduced  by  the  halogens  (178).      This  10 


*i8 


ORG  auk:  chemistry. 


seeu  from  the  folloving  table,  coutAining  the  ralaes  of  the  dls- 
acKnatiiin  constant,  A',  for  B«reral  xcids: 


Xitin». 


Ac«ttc  Acid ,. , 

(nv«i>m«  Acid  (n7droxr4«4ile  A«td) 

Pro|ii<'iiii"  Anid    

LaaU:  Aclii  (a-llydmiyproplonic  Add). . 
/y.li]nlnisy pri)pii>u  'c  Atid 


Pamiulk. 


CH.-COOU 

C'ii,ori-C'>oH 

CH,.tH,-a)OH 

CH,-CHuH.CU)a 

CH/tH-CHf-COUH 


r. 


000190 

o-oias 
0-ooati 


On  hcauiig,  tho  oi-h^drtai/-ac\d$  L-aailj  loee  water,  tvo  mole- 

cnlos  of  llic  Iiittcr  liem^  minu1tnii(>ous1y  ^yWi  olT  from  two  inolociilcs 
of  Rcirl  ;tliU  renction  tiiki-u  plAoo  between  tho  liy(lroxyl-gmQ|i  of  one 
molernlp  «)i(]  the  carboxyl-gronp  of  the  other.  In  this  wny,  lactic 
acid  vieldti  lactidc: 


CH,-CH|oiT  H|OOC 


CH,-CHOOC 

Ooo— rircri,. 


Tho  formula  of  this  compound  ehowe  that  it  ia  a  double  ester,  ita 
constitution  being  provod  by  \U  bohaviotir  when  boiled  with  watpr 
or  dilute  acids:  like  thw  ntiterg,  it  ia  wiponified,  yielding  laclic  aoid. 
fi-Hydroxy-aeids  rpudiiy  gplit  off  water,  with  formation  of 
unitaturutod  ucids; 


=  H,0  -f  OH,-CE:CUOO{)H. 


CILtUCHCOOU 

^HyilnxT)  billy  lie  mI>I 

When  ft /^hydroXJ■-(lcid  is  boiled  willi  vxcowor  n  10  percent,  solu- 
tdoc  of  catuitic  aoda,  it  is  partly  vmivfried  iiilo  xn  aj9-,and  pnnly  into 
a  jS^-unsaturated  acid,  while  a  portion  roniuiiu  uiiactod  upon.  An 
eqatllbrium  Is  thus  rciftuliod  : 

R.0H:CH.CH,.COOII  '^  R.CH.CHOUCH.COOH 


^R.CH,.Cn:CH-COOH. 

If  thi«  r«inctlon  isreallj'n  rerorsibloonc,  the  same  point  of  oquilibrium 
sliotild  be  readied  by  slartiiit^frum  lh«  b)-«lrox;--acid,  or  from  either  of 
Hie  iwo  nnsatumtod  acids.    IIttig  prared  tbat  this  \»  actually  tb*< 
ca»e. 


GLYCOLUCANO  LACTiC  ACIDS,  ^19 

y-  and  rf- hydro jy-acifis  lose  w»ter,  with  formation  of  inner 
ridefi>  c»Ued  lactones  (178  and  186) : 

CH-CH,CH-00  CILCH,-0H.CO. 

loll       ^|o  ' 0 

T-Bj-drozrliutjnic  acid  BuijrulacioDB 

OlyooUic  Acid,  C,H,0„ 

'     IH.  (iiyc(^lie  actd  Is  jinwent  in  unrijie  grajM-w.     It  Is  lutoally  pre- 
parod  by  trcAtltiK  monochloroacotic  ncid  nith  cauetk  potash: 


W: 


COOU-CntlOr+KlOH  =  COOU.C'U,OH  4-  KCJ. 

Glfcollic  ncid  U-a  cryetnlliae  solid,  molting  at  80';  it  is  rery  readily 
Mdilbl^  in  vxirr,  iilvttlinl,  and  I'tlier:  Wm  culciiim  khII  ilissuli'M  witli 
diflSculty  in  wAlf>r.  Whtn  diatiUed  in  ixtcuo,  glycoUic  ftctd  Bplita  off 
water,  with  formation  of  gljreollido: 

OH,{>|infOlCO  CH,0-CO 

I       I     =  aH,o  +  I       I 

00  0  [JTHolc-n,  CO-O-CH, 

Olyoellld* 

lactic  Acids.  C,H«0,. 

185.  Two  laeiic  acidn  are  known,  diflering  from  one  another 
in  the  position  ocwipied  by  the  hydroxyl-groiip;  Ihey  «re 
a-liydroiypropioaic  Muid.  (_'lI,-CHOtl' COOlI.  and  /J-hydroxy- 
propionic ncid,  C11,0H •  CH,-  COOH.  The  firdt  of  theBo  ia  oniinnry 
lactic  ucid. 

<r<H>*dr(]x  J  propionic  acid  can  be  obtained  synthotic&]|j  by 
the  met^tKls  duscrilied  in  182,  aUhuiigh  it  is  usually  prepared 
by  other  meanA.  In  preseiioe  of  an  organized  ferment,  mlled  the 
"lactic  arid  ImciUus,"  curtain  Miigant,  aiich  aa  milk-sngar,  cane- 
SDgari  and  grape-siiKiir.  undcrfio  "  lactic  tcroiuntution,"  the  prin- 
cipal product  being  laotio  acid.  Tht^e  bacilli  occur,  for  example, 
in  deeayiug  ehoesie,  and  eHTinot  live  in  a  Holntion  of  lactic  acid  of 
more  than  a  certain  concentration;  in  order  to  make  fernientAtiou 

eon,  chalk  ifl  added,  which  neulralizcN  thtt  lactic  acid  formed. 

!<actio  acid  can  aUo  be  prcimrL'd   by  heating   glaooee  or  iuvcri- 
augar  with  catustic  sodiL 


9>0 


OnCANIC  CHEMISTRY. 


Lftctio  arid  deriTns  itn  name  from  it«  prosenoe  in  Bonr  milk, 
ae  a  result  of  the  fflrnientaUnn  of  the  inilk-nigar  present.  Tbe 
faint  aci<I  odour  poseeseed  by  8onr  milk  is  due,  not  to  lactic  acid» 
but  to  tnicea  of  voluLile  fuLLy  HoitU  gimullaneoiigly  (ortned;  lactic 
acid  iut'U  is  odonrlusn.  Ijit-tio  aL-id  iilwt  occur*  in  otWr  fcrmi'nled 
eiibatiLUL-i'K.  <iud]  utf  Snufrkrmit.  Aud  in  largo  (jiiuiititios  in  ensilage, 
lined  for  feeding  cattle,  wliieh  is  prejuired  by  sulimitting  pUcs  oi\ 
^rufix,  ctovfT,  etc,  to  pressure. 

lactic  acid  is  puriticd  by  distQlinf;  tho  ftqu«ous  acid  at  rcry 
low  pressures  (1  mm.),  when  it  is  obtained  as  a  cryirtallino 
solid  molting  at  1)4^.  It  iei  moro  umially  met  with  in  the  form  of 
A  colonrleiui,  iiynipy  liquid  nf  strongly  iu>id  tuiiti>,  and  containing 
water.  When  heated  under  ordinary  pn'ssure,  with  the  object 
of  removing  watnr,  it  is  partially  converted  into  tho  anhydride 
(183)  even  before  compli^tc  debydnUiun  liats  tuken  place;  this  can 
be  detected  by  the  diminution  of  the  8cid-e<|uivnlent  on  titration. 
It«  zino  Halt  forms  wcU-deQned  cryittala  with  throe  nioloculos  of 
water. 

The  cuQuCilution  of  loctii^  a^id  is  deduced  from  its  formation 
from,  tmetaldc-hydo  by  the  eyanhydrin  itynthesis  (182,  5),  and  by 
the  ozidotioiL  of  propyleueglycol.  When  bw-'tic  acid  is  heated, 
atone,  or  with  dilntc  sulphuric  acid,  it  splits  up  into  aoetaldehyde 
aud  foruio  M^d: 


CH,-CHQ|irC00lI|    -.   CU.'Cg  +11C00H. 

This  deoompowtion  may  be  looked  upon  as  a  reversal  of  the 
cyniiliydrin  HyniheHis,  and  is  eliuracteriHtin  of  many  ur-hydroxy- 
acida. 

n 

lActic  ucid,  (!II,-U<C001I,  contains  one  aHymmetric  rarbon 

atom.    In  occordancu  with  tho  principles  laid  down  in  63,  itoaghfc 

to  exist  in  three  isomeric  nioditioations;  all  of  theao  arc  knowu. 
Ordinary  lactic  ucid,  obt^iiued  by  syntbema  ur  fermontation,  ig 
racemie;  that  is  to  say,  it  coasiiils  of  equal  (|uantitlus  of  the  dexiro- 
itotd  and  Isvo-acid,  and  is  therefore  optically  inactive.  The 
dextro-lacticand  liL>vu>laclii;  ucide  can  be  vbtoiued  from  the  inactive 
modification  by  methods  described  in  196.      Tlie  dextro-rotatory 


STF.REOIS0MEHSSM  OF  THE  LACTIC  ACIDS. 


231 


TArietj  U  B  cgn8titn«nt  of  mcst-juicee,  and  is  therefore  soinetiinM 
callw]  sarcolndic  aciil. 

186.  Ifc  tuu  just  heen  etatcd  that  RyntheRis  ytol(l«  inactive 
Uctic  kcid.  It  in  araully  not  poaniblo  to  preparo  optically  active 
pT«dllct«  from  inactive  subetancee  by  wholly  clicniiral  moana. 
Since  the  inactive  niodi&cation  conBisis  of  cqnal  pnrtK  of  ilextro- 
rotatory  and  lievo'rotatory  subetnnco,  both  of  the«e  must  b« 
formed  in  erjiial  qnantlties  in  the  syntheHtK.  Tho  question  arises, 
»hy  this  16  80,  and  an  insight  into  the  phenomcuoa  is  afforded 
by  a  consideration  of  the  following  examples. 

The  nitrilo  of  lactic  acid  is  obtained  by  the  aililition  of  hydro- 
cyanic acid  to  ncotaldi'bydc  (188,  5),  the  structuTsl  formula  of 
which  is  represented  in  Fig.  53: 


CH, 


CH, 


CL d 


Pio.  ca. 

At-KTALOICnVtlC. 


oni 


or 


H 


OH 


CH 


H 


CN 


Fio.  Si. 

LlCTOHmULB. 


on 

Fig.  8V 
LAciosrrntLB 


The  addition  of  U-CN  can  tako  place  in  two  way«;  theoxygen, 
which  18  doubly  linki><l  to  the  (■(•ntral  carbnn  atom  of  the  figure, 
becomes  Revered  either  from  the  bond  e,  oi  d.  In  tho  first  cusp, 
the  group  CN  becomes  linked  toe  (Fig.  54),  and  a  hydroxyl- 
group  is  Formed  at  d\  in  the  second  oa«c  tbi«  is  rcverited  (Kig.  55). 
The  configurations  thus  obtainod  are  mirror-images  of  each  other, 
and  cannot  be  made  to  coincide,  they  represent  asymmetTic 
C-atome. 

The  possibility  of  the  formation  of  both  active  components  in 
thus  evident,  and  that  thetto  mimt  bu  formed  in  equal  amounts  is 
seen  by  a  consideration  of  the  probalnlliy  of  their  funuatioti.  This 
is  alike  for  both,  since  d  and  e  occupy  simitar  positions  with 
respect  to  n  and  b,  and  Ihern  is  therefore  no  tendency  for  the 
oxygen  to  ri^main  linked  to  the  one  more  than  to  the  other. 

In  the  example  just  given,  an  asii'mmetrit;  carbon  at»m  has 
lesolted  from  an  M<f(ji^i«»- reaction.  The  following  Ir  an  example 
of  tho  formation,  by  suietUution,  of  a  compound  containing  Mich 


««z 


ORGANIC  CHEMISTRY. 


an  atom.  «-l>romopropionio  acul,    ii>^<no&H'  '*"  **  *>b^'"^' 

from  |)n>pionic  acid,  ju>^<coit[i'    By  i*plftc«m«ut  of  He  and 

ltd  resptfclivel;,  two  acids  of  opposite  rotation  are  produood,  the 
probabithj  of  tlie  formation  of  one  beiu^  equal  to  that  of  the 
formnlinii  of  the  otiit-r. 

C*i  III  pounds  coiitaiiitiig  an  'asymmctrio  carbon  atom  can  aho 
result  from  the  aplitting-off  of  a  group,  aa  In  the  formation  of 

("•LI  T.I 

meihylctfaylacotic    acidi    /<  i?  ^^^poOH'    ^^    methylethyl- 

e 

malonift  acid,  ^^f  >^<(:ooir'  ^^  ^^^  °^  ^^'-    "^^^  probability 

d 

that  this  will  take  place  at  e  and  at  d  U  eijuat,  so  that  an  inactire , 
mixtart!  is  producvi]. 

When  optically  active  lat-tin  ncids,  and  optically  active  snb- 
stanccH  in  gcnoml,  are  strongly  heuted,  they  arc  convened  into  the 
opticiJIy  inartivo  modiliuitifln,  containing  ojiial  pn>purtions  of  tlie 
dextro-modi&cation  and  Iiovo-iuodification.  This  necoeeitates  the 
conversion  of  one-half  of  the  optically  aetive  aubstance  into  its 
optiud  ieoroer,  it  being  eiifReieiit  that  two  of  the  grAups  or  atoms 
liiikt'd  to  the  asymmi'trie  C-iitoiii  ehoiiid  change  pliiceB.  In  order  to 
convert  Fig.  56  into  Us  mirror- image,  Fig.  BY,  it  m  only  t^seutial. 
for  tixumple,  for  B  aud  !>  to  exchange  poBitions.      Thia  can  only 


Km.  30. 


Kio.  5!. 


happen  throngh  a  breaking  of  the  bonds  between  B  and  D  and  the 
carton  atom,  for  a  period  liowever  brief,  followed  by  a  reunion, 
either,  a»  nt  firat,  B  to  b  and  I)  to  //,  or  in  tlm  reverse  order, 
D  to  i  and  B  to  d.     In  couw<iuence  of  the  aiinilurity  of  the  poM-' 
tions  occupied  by  b  and  d  with  rotpwt  to  u  and  c,  the  probability 


HYURjICRYUC  AaOAND  LACTONES. 


221 


of  the  union  of  B  with  h  and  D  with  tl  Is  vqiial  to  that  of  the  uDina 
of  n  with  b  and  B  with  d.  As  i\  result  of  tliis.  doxtro-rolatory  and 
Isvo-rotntory  molecule*  ore  formed  iu  equal  numbers,  eo  thut  after 
heating,  th«  Riibstancc  \»  oplicnlly  inactive. 

OptfcAl  iDMUrity  i«  namntxmo*  dweloped  without  thd  kid  of  butt. 
Waldem  found  that,  tliu  dexcrD-rDtulory  iaobutjrl  c£t«r  of  l)romupn> 
pionic  a<i\i\,  C'Hi'Cimr-COOL'tUi,  and  eoine  other oompoundsconlAin- 
in)[  a  Bi'siCoEu  ill  uciioii  with  iia  lusjiuniutric  0-aroin,  bucmuo  uptionlly 
inncUra  through  being  liopt  forthrtwor  faiir years  at  ttioonliimr)'  tvni> 
peratua'.  The  volocity  of  tmiisformniion  at  ordinary  tompciutiiras. 
for  most  EubBtauo(>s  tuu  small  ta  b«  apfireciablo  after  (he  lapHu  of  nvoii 
toDg  pnriodii— «»d  only  iiieaaii mbla  m  hiijlier  teni[)er&turcR,  «bi«h 
liave  an  iicciTlftrntitig  etTect  upon  most  roaotions — has  in  these  oases  a 
mcnsurablo  valuer 

1S7.  fi'liydrorypropionic  acid,  or  hydmerj/lic  aeid,  lias  the  formula 
CUiOU-C'Ht'COOH,  and  iita  typv  ot  ihe  y:f-bydi-oxy-noids.  It  can  bo 
sytitbM'lii>c]  from  «iltiylt$ne  by  the  oddilion  of  bj-pochloroiui  acid,  UOCI, 
trealmcDt  of  ttic  additioD>product  witLi  potoaaium  cyauide,  and 
bydroiysiii  ut  tin*  mulling  nitrtl*: 

cn,:rH,-.<m,oH.rH,t!i  -^  cH.oiinr.cN  ->  cn.on-OH.txjoH. 

Ettayktwi         al/oolclilorlirilriu  Ol^ixilojruilijdrln  B-Hjilriiiii'propiaitic 

This  oompound  can  also  he  ohtAtned  from  |0-iodopropianio  acid.   It 
baa  ft  nynipy  conniatency,  and  chiefly  differs  from  a-hydroxypropionio 
ncid  in  being  (lc>com  posed  on  beating,  wllbloaiof  water  and  fortnaCioa. 
of  acrylic  acid  (IM). 

Aldol  (llSi  in  cimvorkd  by  oxidatian  into  fihydrtiTf/hutyrtc  acid, 
CHcCUOH-t'Ui'COOII,  reliidi  ousily  loat-a  wbIlt,  fonniiig  crotonio 
acid.  Tba  conatiiuiion  of  jd-hyilruxybiityHc  acid  follows  from  its 
formation  by  the  reduction  of  ilie  corresponding  Icctouic  ncid,  ncoto- 
•eetic  aciii  (SSBj. 

LHtonei. 

188.  It  was  mentioued  (178  And  183)  that  the  ^'-hydroxy- 
■cide  low  water  very  readily,  with  formation  of  liiPtone«.  So  ^Twit 
is  this  leiidi'iiLy  tliat  aoiiie  ^'-kyilroxy-aoidti,  whon  sot  fr««  from 
tbeir  salts,  at  oncu  tipltt  off  one  molecule  of  water,  jieMing  a 
laetoiif.  Tliis  phniomeiion  \«  another  example  of  the  readineu 
with  which  riug-compoHnds  containing  four  carbon  atoms  are 
forroed  (169).  In  many  cases  the  ^'-hydroxy-aeidH  aro  not  known 
in  tho  free  state,  but  only  in  the  form  of  esters,  milts,  or  amidos. 
The  lactones  aru  stable  towards  an  atfueous  solution  of  sodium 


*u 


ORG  Attic  CHEMISTRY. 


curbonHt«,  hut  are  uouvert«<l  by  the  hjdroxideit  of  the  alluili-metals 
into  saltd  of  ^'•hydroxy-iurida;  this  rcuction  proves  their  cou9tiTu< 
tion,  Thcyouiy  bo  loukod  npuu  lui  tbv  innor  c«t«rK  of  the  hjdroij'* 
acids. 

The  lactoutw  van  be  {trepared  byeeveral  rnethuds.  Thiu,  icidi 
containing  a  duubk-  boud  Mt  the  fiy-  or  j-d-jiotiitmii  are  readily  coii- 
Tert«d  into  lactoues  by  warming  with  dilute  enlphuric  acid.  The 
formation  of  lactunut  in  tbia  wuy  nmj  be  lookvd  upon  as  BD  addi- 
tion of  the  curboxyl-group  tA  thu  doublu  bond: 

H-(fH:dHCH,-00  =  R-0HCH,-OH,CO. 
hA  ! '. A 

Unsaturated  acids  J^  (llO><!an  be  obtained  by  several  molhods. 
ODD  bflitig  the  AOtion  of  aldelifdoa  upon  M»iiiiin  Bucdnate  in  presence 
of  aoetiv  anhyrfrtde : 


,.H 


,Mt 


'""|i)MX>0;Hi. 


CU,.CJJ  +  HjCCOOH    _    CH.ClIUC.COOH 

By  olimiiialiou  of  ouu  molecule  of  water,  lUftre  reaulta  a  laototw-aotd, 
CH.CHCH  CO,H  ^ 

O— CO 

wblclt,  on  dry  dialillAtlon,  loaes  CO*,  yielding  Ilie  unsaturated  aoid:. 

CH»-CH.CH.|tA|ir 

CH,  -»  OH,-CH-CRCH,COOn. 


6 


-lo 


Another  method  for  the  preparation  of  lactonea  in  the  redaction 
of  y-ketoniu  tuAAn,  the  synthesis  of  whtoh  will  be  deiieribcd  Ut«i'. 
($>and  c-lactoneH  Hrc  also  known. 

On  boiling  with  water,  the  Inctoiies  are  partly  converted  into 
the  correspond iog  hydroxyacids:  the  quantity  of  acid  formed  is 
in  part  dependent  npon  the  amount  of  water  present.  A  state  of 
etiuilibrium  is  arrived  at  betw^n  the  acid,  and  the  Lictone  4- 
water: 


CH.OH  CH, 


cn.-cooii 


r-Hjdrozrbutxrio  «itd 


CH,-CU,CH,CO  +  H,0. 

I i 

BuljrruWclonF 


UCTOHES. 


»5 


If  the  molecular  concentration  per  litre  of  the  y-hydroiybntyric 
avid  is  A,  and  if,  after  tlio  Ispeo  of  a  time  ^  x  moloeules  havi>i  bocn 
converted  into  luctoue,  the  velocity  of  lactoue-forniatioti  iLt  tliat 
inetant,  j*,  is  givou  by  the  following  eqiintiou,  in  which  it  is  tha 
nmvtioii  i-onataiit: 

»  =  k{A  —  a:). 

Bnt  the  reverse  also  takes  plarp,  the  acid  being  rogeneratcd  from 
the  lactone  and  water.  If  the  lai^tone  is  diwiolv'ed  in  a  Urge  exceiu 
of  water,  no  u|)pn;(- initio  error,  in  introduced  by  aiwuming  the 
qnantit  J  of  thi>  latter  tu  bi-  constant.  Tlio  velocity  s'  of  this  rBrcrso 
reaction  is  then  rr^prceentcd  by  the  equation 

in  which  C  ia  again  the  reaction  oonetaut.  The  total  velocity  of 
the  lactone- fo  mat  ion  for  etRli  instant  \&,  tberoforo,  oqual  to  the 
difference  between  thege  volooitiea: 


g  —  a'  ~  -fT  =  ^(A  —  z)  —  k'x 


(I) 


When  eqailibriuiii  is  reacliud,  n  =  s';  and  if  the  value  otx  ai  this 
|h>int  boa  become  equal  to  jc, .  then 


k(A  -  X,)  -  X-'x,  =  0, 


or 


=  — IL 


Wa^ 


(a) 


Eqnstione  1  and  S  can  be  solved  for  k  and  k'.  The  same 
method  of  calculation  may  be  Hpplied  to  eiiter-fomiation  from  acid 
and  alcohol,  by  which  tlic  reaction  (constant  ot  the  catur-fomiatiou, 
nnd  of  the  cster-dt'c^mpodition,  can  tic  computed. 

ITio  lactoncB  form  addition-producta  witli  hydrobromic  acid  as 
wen  as  with  water,  yielding  ^'-bromo-acida,  the  oonetitntion  of 
which  follows  from  their  reconversion  into  hietone  (I7B).  Tho 
lactones  also  fomi  ailrlition>productii  with  ammonia,  yielding  the 
amides  of  the  ;'-hydroxy-acids. 

m.  DIBASIC   HTDB0XT-ACID8, 

1I9-    The   umpleat    member    of    this    series    is    tartrontc 
COOlI'CHOnCOOII.    It  cnii  buobiaiaed  by  the  action  of  moSstozlde^ 
nf  illver  upon  brotnoRia.Ioina  acid,  and  ia  a  cryslalline  solid,  melliog  at 
IW  with  evoliilion  wf  00,,    Tlie  glyoolUc  wld.  CH,OHfOOH.  thus 
formed,  at  ouc«  1os«h  water,  yielding  a  pGlynivr  of  glyoollide  (164). 


936 


OkCANiC  CHEMISTRY. 


190.  A  Biibstanee  of  greatur  importance  in  malic  arid,  C.H^Oj, 
which  U  preeeot  lu  various  uuriiH!  fniits.  anil  U  beat  preiiarud  from 
unripe  roountaiD-Mih  berried.  It  is  u  rrj-fitalliue  soliil.  melting  al 
100°,  and  la  rcadll;  solnblt}  in  u'uter  »nd  in  alcohol.  Natural 
malic  acid  ie  optically  actirtr. 

It  is  poeeiblo  to  prov«  iu  aovoiul  vajn  that  malic  acid  is 
hydroxyanccinic  aoid,  COOil-CHOH.OK.-COOH.  Among  thw 
are  it«  rednntion  t^  succrinic  aoid  hy  hunting  with  hydrjodio  ncid, 
and  itd  convention  into  mnnoohlomtvucrinic  acid  by  the  aotion  of 
phosphciruti  pcnbachloride,  etc.  Its  alcoholic  character  is  indicated 
by  tht>  forniutiou  uf  uu  ocotatfi  when  its  diethyl  eetur  is  treated ' 
with  Hcctyl  chloride. 

The  formation  of  fumaric  and  maJoic  acids  from  malic  acid 
under  the  influence  of  hcuvt  ha»  been  alnmdy  mentioned  (170).  Ln 
addition  to  tho  natunU  Imvo-rotatory  ncid,  beth  n  doxtro-rotaiory 
and  an  inactive  modification  are  known.  The  latter  can  be  split 
np,  by  fractionftl  rrvKtallixittioi]  of  \\s  cinchonine  a«Jt,  into  iis  ta'O 
optically  artive  components.  As  eoeti  from  its  tttructural  formula, 
malic  acid  contains  an  aeTmmetric  C-atom. 


Tartaric  Acids.  (',11,0,. 

191.  Four  acids  of  this  compoailion  are  known;  all  have  the 
constUutiona]  formula 

COOH.CHOH-CHOH-COOH. 

Ihtj  are  called  dtxtro-rotiUvry  tartaric  acid,  Imvo-rolatory  tar- 
taric aci4,  racemic  acid,  and  invsotartaric  acid;  the  last  two  are 
optifstlly  inactive.  Their  mnstitutiou  is  proved  by  their  formation 
from  the  dibruraoHUccinJc  acids — obtained  froDi  fiimaric  or  ma]*'ic 
acids  by  the  action  of  bromiuei — by  boiling  their  silver  salts  with 
water,  as  w«ll  us  by  their  production  from  glyoxal  by  the  cyitn- 
hydrin  uynthcsis.  Tho  inactive  modifications  are  produced  by  the^ 
rc<actione  (186>. 

In  a<'cordnnce  with  the  conRtitutional  formula  given  above,  the 
tartaric  aeidH  ooutnin  two  asymmetric  C-atoms  in  tlit*  molecule, 
and  it  is  neceswry  to  consider  how  many  sterooisomurs  are  Iheo- 
rcticnlly  possible. 

The  formnla  nf  a  Hub«Um-c  of  tlm  kind  may  be  rcprcMlited  by 
C{ahe) — C((/r/).    The  groups  linked  to  the  wymmotrio  C-atoms  are 


STEREOISOMERISM  OF  THE  TARTARIC  ACIDS. 


337 


I 


in  this  g«Qcra]  foruiiila  dieeimiUr;  the  two  symmetric  C-Atoms 
are  aunniocl  to  b«  unlike.  Hiucv  the  modo  of  nrrangemcnt  of  the 
groups  relfttiTo  to  etwh  at  these  C-alonifi  rBuuItu  iu  duxtro-Totation 
and  lasro-rotAtiou  reiipBftivvlT,  the  following  t-ombiuatioiis  are 
powiblo  ia  tlw  molecule  of  u  mlutiuicu  cvntniuiu^  two  uymmeiric 
C-atoms: 


C(abc) 

1 

Dextro 

8 

Dextro 

3 

L»TD 

1 

Lsevo 

Dextro 

Laaro 

L»TO 

Uexir 

I 

I 


There  arp,  thereforp,  four  isomers  possihle,  njiart  from  t,!io  optically 
inactive  modifications  containing  etjnal  ({UHtititip»  of  two  of  theM 
(1  and  3,  t  and  4). 

Since  tartario  acid,  howovcr.  contiiiiis  two  similar  asymiiit-tric 
0<AtoiDi,  that  is  to  eay,  asymiautric  C'-utoma  in  uniuu  with  eiuiiiar 
groups,  'i  and  4  become  identical,  Icoving  so  fur  three  isomers  po«- 
gible.     I  and  '^  hnnj^  nbln  to  unite,  to  form  a  racomic  compoand, 

total  numl>er  of  poRsibto  isomer?  is  raib«d  lo  four: 


■  12  3  4 

■  CH(OU)(COOH)     Dextro    Dextro    h«..o    i^tivo  combin*. 

I 


:H(0H)(C00U)    Doxtni    laTo       Lievo 


tion  of  1  and  3 


The  four  acids.  C^H^O,,  mentioned  above,  correspond  in  thoir 
properties  to  tho  four  theoretically  possible  isomers.  Dextro- 
tartaric  and  Isvo-tartaric  a<'id»  muttt  )>«  rc>]iri>Bc»nted  respectively 
by  1  and  3,  ^nco  in  theiw  botli  OatomB  rotate  the  plane  of  polar- 
ization in  Lbe  same  dir«L'tion.  and  should,  theri'fort?,  reinforce 
ODcaajthcr'tt  mlluencc.  The  optically  itiuctivc  nicKolunuric  acid, 
vbow  two  oppositely  rotatory  C'-utoma  ncutroJize  i>acli  other,  is 
reiire«ented  by  3.     Finally,  the  ieonior  '1  it  racuinic  acid. 

An  important  dilTcrerii^e  osi»t8  betwcon  the  two  optically  inactire 
isomers,  nicemic  and  mpsotartarie  acid.  The  former,  obtained  by 
mixing  equal  quantitlps  of  tho  dpstro-aoid  and  lievo-arid,  oar  be 
split  up  inl4j  iU  vomponcntH ;  the  hitter,  coniiiaLing  only  of  one 
kind  of  molecuW,  cannot  bo  split  up.     The  rotation  caused  by 


»8 


ORGAffK  CHEMISTRY. 


the  dextro-acid  is  equal  in  nmount  bnt  oppoaite  in  sigu  to  thot 

caneed  by  the  laevo-acid. 

£mil  Fischer  hae  introduced  a  simpio  mode  of  irritin;  the 

spaciiil  formula)  of  optically  active  oompounila,  of  which  frequent 

UBo  will  be  made  hiter.     Hie  repneseutatiou  in  upactr  of  two  C-atoins 

Cnic 
in  uaion^  in  %  oomponiul  |  ,  j»  shown  in  Vig  58  (169). 


Fio.». 


If  the  two  bonds  uniting  tho  two  carboa  atoms  arc  supposed  to 
lie  in  the  plane  of  the  paper,  then  the  poaitiona  of  a  and  c  are  to 
the  buck,  and  of  &  to  the  front.  If  a,  h,  and  c  are  iinBj;;ined  to  be 
^ojected  ujion  tlie  plane  of  the  pajior.  and  a  and  c  iiiuiullaneously^ 
80  altered  in  positimi  thai  ihcy  lie  iu  theeume  straight  line  at 
right  aaglos  to  the  vertical  axis,  and  b  Uoh  in  Um  axis  produced, 
then  projctition-lifTurc  I  is  obtained : 


A 

f" 

f 

1 

1 

• 

1 

1 

I 

] 

L 

If  Fig.  68  ia  rotated  round  iU  rortioal  axis,  so  that  a,  for  uxniople, 
]te«  in  fi'nnt  of  the  (ibne  of  the  pap«r.  Fig.  S9  \i  obtained,  tlio  pro)i 
tioa  vf  which  U  repras«nte<l  by  II.     Tti6»e  appareiHl^  difforeat  ooo-] 
flgaratioiiK  Ki«  identical. 


STEREOISOMERISM  OF  THE   TARTARIC  ACIDS. 


929 


For  a  chain  of  several  carbon  atoms,    6.g.,   four,    there  is 
obtained  in  an  analogoae  way  the  projection-fignre 


This  will  be  anderstood  it  it  is  imagined  that  the  figures  on  p.  200 
(Fig.  33)  are  bo  placed  that  the  plane  in  which  the  carbon  bonds 
lie  is  at  right  angles  to  that  of  the  paper,  and  the  fignres  in  this 
poBitiou  are  projected  in  the  manner  jnat  described. 

The  projection-formulee  for  the  fonr  isomeric  tartaric  acids  are 
obtained  in  the  following  way.  If  the  projection-figure  for  two 
asymmetric  C-atoma  19  divided  in  the  middle  of  the  vertical  line, 
and  the  npper  half  of  the  figure  rotated  through  180°  in  the 
plane  of  the  paper,  the  similar  grouping  of  HO,  H,  and  COOH 
about  the  asymmetric  C-atoms  in  both  halves. 


HO- 


-H      and      HO- 


COOH 


-H, 


COOH 


indicates  that  both  C-atoms  rotate  the  plane  of  polarization  in  the 
same  direction.  We  shall  arbitrarily  assume  that  this  grouping 
occasions  dextro-rotation. 

When  the  two  carbon  atoms  again  become  united  with  one 
another,  by  transposing  one  of  the  halves  in  the  plane  of  the  paper, 
the  following  figure  results,  and  is  therefore  the  projection*formula 
for  the  dextro-rotatory  acid : 

COOH 


H- 
HO- 


-OH 
-H 


COOH 


a  JO 


oRCAnrcr  ^hbmistry. 


Tile  grouping  'ff'rtVv  tcK^iecfc  to  tho  two  C-atomg  in  the  l»vo- 
routory  acid  niMfii  b©  the  mirror- image  of  that  iu  the  d«xtro- 
rotulory  ^&3);  tba». 


H- 


-OH        and 


H- 


-OU 


i. 


COOH  COOH 

Tho   combination   of  these   two  gives  tho  following  projection- 
formula  for  thv  leero- rotatory  acid; 

COOU 


H- 


-H 
-OH 


coon 

Thoso  roprcsontatione  of  tho  couetitiiLiona  of  dextro-tartario 
and  Ifevo-tartanc  Acid  cannot  be  made  to  coincide  by  altering  their 
position  in  the  plane  of  the  paper,*  and  are  therefore  difft'reut. 

When  tho  acid  contain!)  a  dextro-rotatory  and  a  laevo-rotatory 
C-atom,  us  in  meaotartaric  acid,  th«  arrangement  of  tiie  groups 

Ooxtrv  Ubto 


HO- 


H 


U 


COOH 
and  theii  projection -formala 

HO- 


OH. 


COOH 


HO 


COOH 

-n 
II 


COOH 


"  TliMin  pnijrrlion.fonuula  can  bo  nude  lo  colncidp  l>y  lolulii^  oqb  of  lliom 
tlirongb  180*  about  Ihn  lln<a  HU— H.  It  will  be  Miun  from  a  model,  bowevsr, 
ibnt  tlio  tp<v:iai  forcuulit- cnnnot  be  tnxAv  to  coincide  \iy  tliis  tieatinont.  To 
dvunninc  wbetlior  tUiii  ii  potuiblv  for  xjiitdal  fonuuiw  bv  meuia  of  projeclioa- 
formultP,  kt  is  only  kdmlsflitila  to  tnnspOM  llm  latuir  in  lb«  plkiie  ot  ibe  papsr. 


DEXTROTylKTARiC  MCJD. 


33> 


Tli«  projoctioii'fonnula.  for  r&ceinic  acid  is 

Dfxtro  Lkto 

tOOU  COOK 


H- 
HO- 


ou 


-H 


+ 


HO- 
H- 


COOU 


-U 
■OH 


COOH 


Sextro-tartarie  Acid. 

192.  The  acid  poinsshitu  salt,  t\UjO,K,  is  prcaent  in  the  jnioa 
f)f  grupea,  and  duriug  alcoliolic  fermeutation  is  deposited  on  th« 
bottflm  oJ  the  wiBkH,  being  ©veu  more  (sparingly  soluble  in  dilute 
alcohol  than  in  water.  The  crude  product  is  t-'aHed  "argol";  when 
pnrified,  it  is  kuowu  as  "cream  of  tartar."  To  obtftlu  dwxtro- 
tarturlc  acid,  the  criidu  argol  is  boiled  with  hydrochloric  acid,  and 
tli«  acid  precipitated  as  calcium  tartrate,  CaCJl^O,,  with  milk  of 
linn?.  After  ■washing,  the  calcium  salt  is  treated  vith  an  equi- 
valent quantity  of  aulphtiric  acid,  whieli  precipitatua  culcjum  aul- 
phate,  and  sets  free  the  tartaric  acid;  this  can  bo  obtained  by 
evaporation  in  tlie  form  of  large,  tranBpurent  crystals,  free 
from    water    of    crjTBtallization,    and     having    the    compoftition 

C.H.O.. 

Doxtro-tartaric  acid  melts  at  170*,  is  very  readily  soluble  in 

water,  to  a  less  extent  in  alcohol,  and  is  iuaoltiblo  in  ether.  When 
heated  above  its  melting-point  umlor  atmospheric  pressure,  it 
loses  water  and  yields  various  anhydrides,  according  to  the  intensity 
and  duTation  of  the  heating.  On  heating  further,  it  tnrns  brown, 
with  production  of  a  caramel-tike  odour,  and  at  a  etill  higher  tem- 
perature, chars,  with  iormation  of  pjroracemic  and  pyrotartarie 
acids.  It  cuu  be  converted  into  succinic  acid  by  the  action  of 
certain  bacteria. 

Iq  addition  to  the  acid  potassium,  salt  may  be  mentioned  the 
neutral  polttsf  turn  siilf,  t',H,0,K,,  which  is  readily  soluble  in  water, 
»xi(lpOt(UsiHm  antirMnyl  tartrate, 

3[CooK.ciion.cnoTicoo{SbO)]  +  n,o. 

On  BCconnt  of  ita  medicinal  properties,  the  latter  is  known  as  "  tar- 
tar emetic."  It  is  obtained  by  boiling  acid  potaSGinm  tartrate  with 
tuitimony  oxide  and  water,  aud  iii  readily  Ruhible  in  water. 


«3> 


ORCANtC  CHEMiSTKY. 


The  prooipitation  of  Iivdroxidrji  from  mctallie  nlto — evpiwr 

h5^m3Li<Ic  from  oopjier  Rulplkute,  fur  L>xanipl<?>— is  often  ]>rovoDted 
(161)  bjr  thv  pretieucc  of  turtahc  uoid.  Tht<  ItcjUid  obtuined  bydis- 
iiDlviiiK  cu|)pvr  sulphate,  tArlAnc  aciil.  and  uxci-m  of  caustic:  {lotash 
ill  iviitt-r.  ie  callod  "  Fohling'saolution.''  It  '\n  au  important  meaiid 
of  t^ittinf;  the  rcdmnng  power  of  corapouudti,  sinoc  nwlucinfr-ageiitfl 
imvipitiite  yellow inli- rod  ciiproua  oxide,  or  its  hydroxide,  from  the 
ilirk-bhiB  solution.  In  thin  alkaliutt  copper  Molutiou  the  hydronyl- 
j{n>ii[M  uf  tho  c«utral  C-atoms  hmve  reactud  with  the  rop^>er 
hydroxide,  siuoo  onf  grsmme-moleciile  of  ueutnil  tilkuli  tartrate 
cun  dissolve  one  grammo- molecule  of  copper  hydroxido.  These 
copjier  alkali  tartratofl  hare  nlso  been  oblsiiiod  in  a  er|*ata]Iiiie 
form;  for  example,  tho  compound  C,H,0,>ia,C'u  -^  211,0  is  known, 
Kud  to  it  must  therefore  be  wKiigu»(l  the  cooBtitntional  formnhi 

^^O.CH.COONa  +  '"'°- 

In  aquentia  solution  this  oompound   U  ionized  Into  Na',  and  the 
0-CH-COO' 
eomplex  anion  ^"^o.^h-coo"    ''''''*  **  "howa  by  the  following 

faets.  First,  ths  saliilion  no  longer  givu«  the  ordinary  reaciiona  fur 
eopper  ions;  xlDiough  ttie  liquid  Is  alkntlne,  cop|)vr  hyilroxtde  i&  nol 
precipitated.  Second,  when  tbo  solution  is  olvctrolftcd,  tlie  copper 
g(M<K  iiwarda  tlK  anode.  This  lias  been  prot-»d  by  K^ms  by  the  at'l 
of  tbe  nppnniUis  slioWD  in  Fig.  00,    Uuo  U-tube  CDObtins  copper  sa>- 


Pl0.  M.-'Ki.nn-aoi.raTe  or  ax  ALKALtHS  CorriR  SoumoH. 


.^hate  aolatioo  at  h ;  the  other,  Fefaltng's  eolation  at  <ii  into  both  limba 
of  «Moh  it  then  CMrefully  pourMl  asotolioaof  M)dioiB*alplute.aaade. 
The  ooanoo  surfiieea  of  tbe  »odiutn  nlphato  and  ee^per  nlpbato 
Bolatlon*  in  the  two  U<tulM«  lie  Id  Um  sanw  boriMatal  pUitaL  Vben 
•n  eleotno  earrwiit  it  paued  through  tlte  tabm,  peefeniblj'  arranged  in 
parallel,  and  twt  iu  seneSt  a  differant  rffecl  is  prodnced  on  the  poti- 


L^I^O-TMRTARiC  ANO  RACEMJC  ACIDS. 


'S3 


tfoD  of  IIjO  surrACi-s  or  the  copper  Aolutiona  ia  eacti  tutc.     lu  lb«  cop- j 
por  sulphaio  soluliou,  a  riee  in  level  taken  plAce  at  lite  cathode,  slnoof' 
tbe  Ca-ioDft  ar«  cations,  and  teud  towurda  the  atthodc.     The  rcvorsa 
effect  b  otjaerred  in  the  Peliliii^'s  solution,  showiiig  ibat  here  tbe  cap* 
p«T  forms  \xkrt  of  th«  anion, 

MocooTor,  ttifl  colour  of  Febling'a  solution  ia  a  raacb  more  iat«nM 
blue  Ibaa  tliat  of  a  oop[Hvr  sulphate  solation  of  t^uivnlent  concuntm- 
(lon,  which  iit  <tvidfirtoe  of  the  preaenca  in  Fnhlin^'s  solution  of  a  uom- 
pJcx  ion  eontaining  copper, 

FebliDg'asulutJoii  di-cuiD |>os«t  on  ataudlug,  su  (hat  it  ia  beat  pre- 
pared m  required,  lysr  haa  discovered  a  cnucb  more  stable  nlkaliiiv 
copper  BohitioD,  wbich  can  be  uaed  for  the  aame  parpoaeei  as  that  of 
Peuuku.  Tt  ia  a  mixture  of  copper  sulphate  with  acid  and  nvutrnt 
carb«OAt««  of  potnasiiim,  and  uooiaina  a  aoloble  double  carttouate  of 
e(^>per  nnd  potauium. 

LeTO-tartario  Aoid. 
Lavo-tartarie  aeid  is  obtainod  from  racemic  acid.  With  the 
exception  of  their  caueing  opposite  rotation,  aud  tbe  fact  that  the 
salu  formod  by  the  l«evo-acid  with  tho  optically  actire  alksloida 
differ  in  Hohibility  from  those  derived  from  the  deztro-add  (196), 
the  properties  of  the  laevo-acid  and  ita  ealta  are  identical  with  those 
of  the  dcztro-mod location  and  its  salts. 

Bao«mio  Aoid. 

193.  It  tuui  tieen  alrea<ly  sUtod  (186)  that  optically  active  aiib- 
etanoesiwri  Iw  converted  by  theuutiouof  heat  intoojiticjilly  Inaotire 
ooinponiids;  that  is.  (.rhangbd  into  a  miituro  of  tlie  destro-niodili- 
L-atiun  and  laivo-modiiicutioii  in  ii|ua[  propurlioiia.  This  clmngo 
is  oftuu  fiMiilitiited  l>y  the  pr«8euce  of  cerlain  substuuueii;  thus 
dcxtro-tartaric  aoid  is  easily  converted  into  raccmio  acid  when 
boiled  with  excess  of  a  concentrated  solution  of  caustic  soda. 
MefiOtartaric  acid  is  formed  at  the  same  time  (IM). 

The  optical  inactivity  is  occanionotl  by  convereiou  uf  one  half  < 
tlwdextro-acid  iuto  thu  luivu-ujodiflcation.    If  rormuJa  I  ropressot 

COOH  COOU 


HO- 


-OH 


HO- 


H- 


OOOH 


-a 


-OH 


COOU 
U. 


*4+ 


ORGANIC   CHEMISTRY. 


tbc  dvxtro-Bcid,  then  formula  II  will  correstwiid  vilh  the  Isro-ncM, 
and  tUe  furmtilw  &bavr  that  the  exchange  of  gnraps,  liy  nbiob  an 
active  compound  i»  cuart^rtiil  into  lis  optical  inomcr  (111),  must  in 
this  iostance  take  pince  tit  both  luyramctrio  C-atoma,  in  order  tliat 
tbe  dextro-acid  inuy  yield  Its  Iievo-iwimei'. 

iiacemie  ucirfignotso  soluble  in  water  aathetwrtopticaltyantii-e 
acids,  nnd    dif!F(>ni  in  oryetfillinR   form    fruni  them;    the  ctyHtalfli 
have  the  compontion  tQ^lfi^  +  211,0.     llany  of  iCa  taltH  contaii 
amounts  of  wuter  of  crystallization  diffcnn);  from  those  in  the  ssltll 
of  UiB  corrt-Bponditig  optically  aotivo  isomera.     Itnt'eiiiic  Mid  is  I 
proved  to  consist  of  two  compoucuts  by  its  syotiidaiA  from  sola-' 
tions  of  tho  doxtro-acid  and  the  Irovo-ncid.     If  the  eolations  aro 
concoDtmtod,  Itont  \\i  dov«lop>ed  on  mixing,  and  tho  toes  soluble 
racemic  acid  crystjillizos  out.     Itacemic  acid  mn  also  ho  split  up 
into  the  two  optir^lly  active  modifications. 

Although  racpniir^  acid  iu  the  eolid  state  differs  from  hotli  dextro- 
tartaric  nc-id  and  Itoro-tartaric  acid,  j«t  in  solution,  or  as  ester 
in  the  state  of  vapour,  it  socms  only  to  bo  a  mixtnro  of  thom;  at 
loost,  the  lowering  of  the  freezing- point  produced  by  it  in  dilute 
Bolntion  corresimnilR  to  the  molecular  formula  C,IT,0,,  and  the 
TRponr  density  of  its  ester  to  singlfl,  instesid  of  to  double,  molecules. 

Thn  term  '*  ruceniic*'  i»  applied  to  eubstunces  whose  optical 
inactivity  \&  occasioned  by  their  cousistiug  of  iisomeni  of  equal  and 
opposito  rotatory  power  in  cqni molecular  proportiong.  This 
phenomenon  was  tlrst  obserred  by  Pahtkur  in  hia  reseftrchu  on 
laoentio  acid  (1S6). 

Meaotartaric  Acid. 
194.  Mtsotartttric  acid,  like  racemic  acid,  is  optically  iuBctive, 
but  cannot  be  split  np  into  optically  active  componcDta.      It  Is 
formed  when  dextro-tartaric  acid  is  boiled  for  several  hours  under 
a  reflux-condenser  with  ii  large  excess  of  cauHtic  soda  (193). 

If  formnla  I  ia  a&signed  to  dextro-tartaric  acid,  it  is  evident 
COOIl  COOII 


E- 


HO- 


-OH 

-a. 


HO- 


HO- 


COOH 

I. 


-H 


COOIl 

u. 


STEREOISOMERISM  OF  THE  TARTARIC  ACIDS. 


■0 

»35 


to  convert  it  iato  meaotartaric  acid,  formula  II,  it  is  only  necessary 
for  two  gronps  in  anion  with  a  single  asymmetric  C-atom  to  change 
places,  while  noeinio  acid  can  only  reenlt  through  exchange  of  the 


vH 


CO -OH 


-f-20H     = 


CO«OH 


FiQ.  SI.— UalbTc  Acid. 


CO'OH     H 


or 


COOH       ^ 


COOH 


CO-OH 


H  OH 

FiQ.  S2. — MBeoTABTARic  AciD,    FiQ.  6S, — Mbsotabtario  Acm, 


groups  linked  to  both  C-atoms.  This  affords  an  explauatioa  of  the 
fact  that  when  dextro-tartario  acid  is  heated  with  dilute  hydrochloric 
acid,  or  boiled  with  dilute  caustic  soda,  mesotartario  acid  is  first 
formed,  and  raoemio  acid  only  after  prolonged  heating. 

The  acid  pottusium  salt  of  mesotartario  acid  is  readily  aolnble 
ill  cold  water,  differing  ia  this  way  from  the  correq>onding  salts 
of  the  other  tartaric  acids. 


aje 


ORGANIC  CHEMISTRY. 


I9B.  This  view  of  the  Btmotnre  of  the  tartaric  scids  is  in  complete 
aooord  with  their  relatioa  to  fninario  and  maldia  acid  (ITO),  which, 
on  treatment  with  a  dilnta  aqueotu  solatloa  of  potassinin  permaa- 
ganate,  yield  Tespeotively  raoenuo  and  mesotartario  acid  by  adtUtion 


HOCO 


+a(OH),= 


CO-OH 


Fio.  U. — FuMAsio  Acid, 


H0'*«=Cl-5  ——^ 


HO-CO 


+ 


CX)'OH    B.^^zz—&- 4^C0-OH 

OH 
FiQ.  65. — Racemic  Acid. 


of  two  bydrozyI>{^nps.  Addition  of  20H  to  maleto  acid  may  result 
from  the  breaking  of  the  bond  1,  1'  or  2,  2'  in  Fig.  61,  with  produc- 
tion of  the  coDflgurations  represented  in  Figa.  62  and  83.  The 
projection-formulas  oorrroeponding  to  Figs.  83  and  63  are : 


S7f.REOiSOMERISM  OF  THE   TARTARIC  ACIDS. 
H  OU 


»37 


HO- 


HO- 


-COOH  II- 

aud 
-COOH  U- 


k 
I. 


in 
II. 


-coon 

-COOH 


Theae  apparently  ililTeretit  conflsurations  arc  ideoLioal,  as  maj  bo 
fluU;  seen  by  writing  tha  first  in  ati«lh«r  vsy  (p.  338) : 

on 


OOOH- 

OOOII- 


-H 
-U 


OK 

If  the  last  projciotioTi-formtilA  is  rotak'il  In  Dm  plA.na  ot  tho  paper 
tbiou|i;U  160",  it  vrtU  coiucitlti  iritb  11.  A  coiD]>ariaon  of  tbU  aob«m« 
with  that  in  194  shows  it  to  ha  the  oonfiguratlon  reprefleDting  mcso- 
tartaric  acid.  It  follows  that  adiittion  of  two  liydroxyl-groups  to 
nuUvIc  acid  produces  only  mesntarta.ric  acid. 

A  di9er«Qt  n;»ull  is  oklaiued  by  addition  of  two  OH-groups  to 
fnmanc  acid,  as  will  ho  accn  from  fig*.  64  and  69. 

By  tlio  breaking  of  the  bonda  1,  I',  or  S.  S'  by  addition,  two  coo- 
Hgnrations  are  oblalnMl  which  cannot  be  maile  to  colaolde  by  rotation. 
This  will  bo  better  understood  from  the  following  pTojcciion-formula: 

COOH  COOH 


HO- 


HO- 


-H 
-OOOH 


HO- 


H 
OH 


-H 
-OU 


OOU 

COOH 


COOH- 

a- 


-COOH 


B- 

uo- 


OH 


-OH 


COOH 


A  oomparlHon  of  theso  with  thoeo  on  p.  S9I  shows  that  the  former 
repiwent  deittro-tartario  iind  tero-tarlartc  acldn. 


nB 


ORGANIC  CHEMtSTRY. 


Rftcemio    Siibsteiio«s,  and  their  8ep*ratioa  into  Optically  Actirt 

ConiCituftQCs. 

Ids.  KxpRrienc6  lias  shotrn  that  optically  nctire  iBoment 
rotating  thu  plane  of  polarization  in  oppneitt*  dirocttons,  displajJ 
no  diffurfiaco  in  ttioir  utbor  pli^-sicul  or  in  thtiir  ebcmtcal  propcr- 
tiw,  Tbc;  have  tho  same  eolubilitf,  boUiog-point,  and  melting- 
point;  thoir  B&ltg  crystallizo  with  the  nanio  numbor  of  molonaleit  of 
wiiter  of  cryrtallizatioii,  etc.  It  follows  that  the  separation  of  an 
optically  inat^tire  BnbNtance  into  its  optically  active  components 
rannot  he  rlTe<;ted  by  the  onliiinry  mothoda,  ainco  tlieso  arc  bated 
on  diffcrencos  in  pliysital  pro|wrtiefl. 

Pasteur  has  put  forward  tlirco  methods  for  effecting  thia 
separation.  ""I'hc  flrat  of  tlioso  depends  upon  tho  fart  that  tho  Kalta 
of  raceniic  acids  sometimoe  crystallize  frnm  solution  in  two  forms, 
ouecorreBpondingtothedextro-salt,  andoneto  thelsevo-galt;  tl 
may  aiibsefinently  bo  mochanic-ally  separated.  Pasteur  showui!' 
tliis  for  aodiiim  ammonium  racematn,  C,H,0|,Xa,(NlIJ,-|- 211,0. 
VjIK  't  IIoff  proved  later  that  cn,-8taU  of  the  dcxtro-turtntto  aQd 
Iffivo-tArtrate  are  only  obtained  from  this  eolution  at  temperatures 
bolow  '^8",  tlii»i  boiiig  the  transition-point  for  thaM  iaIU  ("  loor- 
ganic  Chemistry."  70): 

2NaNH,C,H.0,-4U,O  7*  C,H.0„N»,CNHJ,.3H,0  -f-  6H,0. 

Destro-  -f  IVTt>>  N»-Nn,-tartrmM  h'a  NII,-rBceliul* 

Fig.  65  represonts  the  cryatal-forms  of  llio  two  turtratca,  the 
difference  between  tbttm  being  duu  to  tlio  po»itioii8  of  tho  pi 
a  and  b.     Tho  cryatal-lorms  arc  mirror -imagea  of  ouB  anotheM 
and  nannot  b©  made  to  coincide. 

pASTKUH'fl  Kocoiid  method  of  aoparation  depends  upon  a  differ- 
ence in  solnbility  of  the  daltt  of  the  ujiticallr  active  acidii,  when 
thoy  contain  an  o])tically  active  base.  So  long  as  the  buae  with 
whick  a  doxtro-acid  or  a  lB>To-acid  id  united  is  optically  inactive, 
as  in  thv  metallic  eoltu,  the  iutcruul  struuturc  of  the  molocnli) 
remains  unchangod;  tho  constitation  of  tho  salt-moloouloe,  like 
that  of  the  froo  acids,  may  he  represented  by  con figuTntions  which 
are  the  mirror^imageit  of  one  anotiier.  Rnt  tbix  is  not  so  when 
the  dextro-actd  and  the  liero-acid  liave  united  with  an  optically 
active  (for  example,  a  dextro-rotatory)  baae;  the  configarations  of 


SEPARATION  OP  ftACEMtC  COMPOUNDS. 


I 


the  ealt-molccules  ar«  thon  no  longer  mirroT-image«  of  one  another, 
uid  identity  of  phygicsl  pro])ertiF«  must  of  nocessity  coase. 

Kacemic  ucid  can  in  this  vav  he  sepnrat«d  by  oioans  of  Ita 
iuchonine  Bait,  einco  ctnchonine  lipvo-tsrtrate  is  less  soluble  tlian 
the  dcxtro-tartrat*,  and  rrystalliKos  mit  from  eolutiou  firal. 
Strychnine  miiy  lio  advantageously  ueod  in  the  separation  of  lactic 
acid  into  ltd  compononts,  and  other  examples  of  the  same  kind 
might  betiited. 

The  conversion  of  optically  active  subetancoa  into  otbera  whom 
oonfigii  rat  ions  are  no  longer  mirror-images  of  one  another,  can  be 


u 

- 

T 

/ 

J 

/ 

Flo.  89.— CuvaTAi^yoBMB  ov  Tirie  Bodidm  Auuukiuu  Tartiiatim. 

el«d  in  other  wnyB;  thus,  in  the  case  of  acids,  by  the  formation 
'iMer  with  an  optically  active  alcohol.  The  velocity  of  estur- 
formation  with  an  optically  inactive  alcohol  must  be  the  same  for 
both  uomers,  on  accoant  of  the  perfectly  aymmetrical  structure  of 
the  esters  formed;  but  with  an  optically  active  alcohol  the  two 
isomers  ore  not  «8teriQ(>d  ut  tbe  uame  rate,  aiuoe  the  compounds 
formed  are  no  longer  mirror-images  of  one  another,  M.\kckwald 
has  shown  that  when  ritceiiiio  muiidelic  acid  (347,  3)  is  heated  for 
^Kaae  Lonr  at  125^  with  menthol  (363).  an  active  alcohol,  the  oon* 
^BBt«rified  acid  ta  lievo-rotatory. 

^P     Wliilst  the  aolnbility  of  optical  IsomerB  in  an  optically  inactive 
lolvent  is  the  aamo,  it  munt  be  different  in  an  uptically  active 
>lvent.     For,  it  ib  t-rideiit  that  the  solubility  of  a  compound  de- 
euda  on  the  coufigunitiou  of  it*  molecules  aa  well  aa  on  tlioae  of 
the  Rolvent,  since,  ou  the  one  hand,  thu  aolubitily  of  isomL-rs  it  in 
sneral  dissimilar,  and,  on  tbe  other,  the  same  substance  diuolves 
different  aolventa  in  wholly  different  proportions.      It  is  true 
that  optically  active  Isomora  have  a  perfeL'tly  nimilar  atniL-tare,  but 
relation  to  an  optically  active  solvent  their  ooufigurationa  are 


140 


ORGANIC  CHEMISTRY. 


different;  so  that  they  behave  towardii  it  lUce  ordtnaiy  uoineK, 
and  must,  therefore,  have  different  aolDbilitiea.  Kippixo  and 
Port:  have  proved  this  for  mdium  ammonium  racemate  bj  frac> 
tionut  crystallization  fmm  u  oolation  of  dpstrosn,  vhich  is  dextro- 
rotatory ;  in  the  firet  fnictions  thi-y  found  n  markod  preponderance 
in  the  umount  of  the  dcztro-rotatory  salt. 

The  third  method  of  gppnnition  doviuid  by  Pastbcb  depends 
on  thcACtion  of  mould -fungi  {PenteiUium  gluucwm),  or  of  bacteria. 
Thna.  when  racemic  lactic  acid  in  very  dilute  solution  is  treaxe'i 
■with  the  Bariittis  acuU  lavoladici,  after  adiUtion  of  the  necfsarr 
nutriment  for  the  bacteria,  tbo  optically  inactive  solntion  becomea 
IaeTo*rotatory,  einc*  only  the  dextro-rotatory  acid  is  converted  by 
the  bacilli  into  other  gnbetanecs.  A  dilate  Bolutton  of  racemic 
acid,  ioto  which  traces  of  the  mould -fungiis  Ptnicifttum  glaurmit 
hare  been  introduced,  becomes  1teTo>rotatonr,  since  the  fnogas 
propagates  itaelf  with  decomposition  of  the  dextrO'rotatory  acid. 

The  ftecond  and  third  methode  of  separation  are  alike  In  prin- 
ciple. During  their  growth,  the  bacteria  and  fungi  develop  sub- 
stances called  oiuymea,  which  dt-compose  eompounda  in  a  way 
hithiirto  unexplained.  Those  eoKymes  are  optically  active;  hence, 
a  difference  in  their  action  on  the  optical  isomers,  annlogooe  to  that 
described  above,  is  to  be  expected. 

197.  When  a  raoemic  aubstauc«  is  liquid  or  ^aseons,  it  con;iifitfi 
only  of  a  mixture  of  the  two  iaomers;  an  example  of  this  was 
cited  in  coiiueotiou  with  racemic  acid  iu  solution,  and  iu  the  form 
of  esivra  (IM).  If  the  substance  is  ciystalline,  tbere  are  three 
poasibiUtiex. 

First,  the  individual  crystals  may  be  dextro-rotatory  or  leevo- 
rotutory,  so  that  the  two  modiUcationa  cau  be  mccbaDicttUy 
separated.  This  ia  expressed  by  the  statement  that  the  racemic 
BubstaiKie  ia  a  eonglomerafa  of  t}ie  isomers. 

Si-cond,  it  may  be  a  true  eompouuA  of  iho  dextro-modification 
and  lajvo-moditicutiuu,  a  racemic  compound,  tlie  formation  of 
which  may  be  compared  tu  that  of  a  double  nit,  when  a  solution 
eontaiuiog  two  salts  is  allowed  to  cTTstallize  under  06rt*in  oondi- 
tiona. 

The  third  posuibility  is  also  analogous  to  the  crystallization  of 
■alt*iQlutioii8,  whereby  crystals  are  sometimes  obtained  containing 
both  salts,  but  iu  proportioiu  varyiuj;  in  different  crystals. 


somPtimM  liappoiisthnt  the  salb*  rrj-stallizo  together  in  all  propor- 
tionR,  hut  UAtiiilly  tht^ae  vMt  vary  iitilj  between  cvrtsin  limits. 
Tb(!  simuitunoouB  crystuUiuition  of  talta  in  this  way  given  nne  to 
thp  su-colk-ii    mixeil  cri/nlah.      When    this  oucure  with  opticnl 

tisomors,  paudoroiemic  mixed  crygtala  result. 
Which  of  tKee«  throe  kinds  of  erygtaU  cryntallijie  from  n  given 
lolntion  or  fnwd  mnss  of  a  rnceniip  mibstance — a  conglomflmie,  a 
ructunic  compiitiiiil,  or  pseutloracfmic  mixed  enp'stala — dt;penda 
upon  the  temperature  at  which  the  cr>'sUiI ligation  takes  place,  and 
upon  otlicr  conditioiiii.  An  example  of  tins  ban  Ixmn  already 
mcntion(?d,  eodium  ammonium  raccmat*;  when  conccntrat«d  above ' 
28^  tho  racomate  crystallines  from  the  Bolution  of  this  salt;  hclow 
thig  tcmperntiire  a  mixture  of  the  individual  tartrates — the  con- 
^^j^wnerate — is  ohtained. 

^ft  Bjlkhuis  RoozBBtiOx  has  indicated  a  general  method  of  dislin* 
Hgnifiliing  between  thcvse  three  ohisaea  of  compounde.  For  a  con- 
W  glomerate,  thic  ia  simple.  A  saturated  solution  is  made ;  it  will  be 
of  neoeesity  optically  inactive,  and  aitunitcd  alike  for  the  deitro- 
rotatcry  and  for  the  lepTo-rotatory  body.  If  now  tho  solid 
dejtro-com pound  or  lievo-com pound  is  added,  and  the  mixtura 
shaken  up»  nothing  fnrther  will  dissolve,  since  the  liquid  is  already 

»aaturated  with  the  two  isomers;  the  amount  of  dissolved  euh^uce 
it)  etill  the  same,  ami  the  solution  remuine  optically  inactive.     Oa 
the  other  hand,  if  a  nicemic  eompouitd  was  presout,  although  the 
BOluliou  VC&8  saturated  iu  the  firgt  inetauce  with  resjiect  lu  this,  it 
ii  nueatnrnted  wiili  respect  to  the  two  optically  active  modiflca- 
BtJons;  addition  of  the  solid  dextro-rotatory  or  lievo-rotatory  sub- 
^htaurc  would  canae  a  change  in  the  total  quantity  of  aolid  dissolved, 
Fttid  the  liquid    would    become   optically  active.      The   methods 
employed  to  detect  pdeiidoraeemic  mixed  crystaU  are  sometimes 
l«ee  Bioiple. 

IT.    POLYBASIC   HTDftOZY-AGIDS. 

168.  Of  these  acida  it  will  be  sufficient  to  deecrilw  the  tribaaic 

^iirif  acid,  C,EI,0,,  wbich  is  widely  distribated  in  the  vegetable 

icingdom,  and  in  also  found  in  cows'  milk.     It  ia  prepared  from 

le  jnleo  of  nuripe  lemons,  in  which  it  is  present  to  the  extent  of 

-7f.     The  tric&lcium  salt  of  citric  acid  is  easily  soluble  in  cold 

Iter,  but  very  slightly  in  boiling  water;  this  property  is  made 

use  of  for  its  sepamtion  from  lemon  jnice,  the  acid  being  obtained 


M* 


ORGMmc  CHEMISTRY. 


in  the  froe  stato  bj  the  subacqacnt  udditiun  of  sulpbaric  acid. 
AnotliL-r  ttx^hnicul  methud  for  its  prcpunitioD  lU-peDdA  upon  the 
liwt  tbut  ccrtMa  mould-fimgi  {titromiji-Kt  p/efferianuf  and 
V.  glaber)  produce  considerable  quantities  of  citric  acid  from 
glucose  or  mgar. 

Citric  acid  can  be  obtained  Byntbetically  b;  n  method  which 
proven  its  oonHtltntion.  On  oxidation,  Byinmctriciil  dichlorfaydrin, 
Cn,C10II0H-0II,CI  (162).  IB  converted  iato  ajmmetrical  di- 
chloroucctonc,  CU,01-C0-01I,C1.     Tho  cya&bvdrio  evntheeie con- 

on 

verta  this  into  CH,C1-G^CH,C],  vhich,   on   hydrolrsis,   yields 

.OH 

tho  hvdroxy-acid,  CH,C1-C^CH,CL      On  treatment  of  this  com- 

^COOH 
po^ind  with  potassium  cranide,  a  dicyaaido  is  lormed,  -vrhich  is 
converted  by  hydrolysia  into  citric  acid: 


Tycoon 

CH,CN 


CILCOOU 
(].     OH 

cH,'Coon 


The  alcoholic  character  of  citric  acid  ia  indicuted  by  the  reac- 
tion of  its  tricthyl  ester  with  acetyl  chloride,  an  acetyl -compound 
being  formed. 

Citric  acid  forms  well-doflned  crystals  containing  one  moleonle 
of  vat«r  of  crygtaltizatioii,  aud  is  readily  soluble  in  water  and 
alcohol.  It  loses  its  water  of  crystntlization  at  130°,  and  meltti  at 
153°.  It  is  used  in  the  manufacture  of  lemonade,  and  io  calico- 
printing. 


T.    A11IR0.A0IOB. 

199.  Tho  amino-Rcid*  contain  one  or  more  amido-gronps  in 
direct  union  with  carbon.  They  are  of  phyxiological  importuneo, 
since  many  of  them  result  from  the  decomposition  of  atbumitu. 
and  Home  of  them  uUo  occur  in  nature.  They  can  be  obtained 
synthet  icully  by  the  following  methods. 

1.  Uy  the  action  of  the  tuilogcn-BQbstitntod  fatty  acids  on 
■mmonin,  n  method  nnalogoue  to  the  formation  of  amines: 

H,y|]l-f-CllH,CC0OH  =  H.N.CU,  COOH-l-HCl. 


MMMO-ytanS. 


us 


3.  Bj  roducLioD  of  oximuB  with  sodium  amftlgam: 
EC(NOH).COOH  +  4H  =  R.CHNH,.CO0H+  H,0. 

TluB  is,  therefore,  »  method  for  coaverting  Icetooic  acida    into 
amino-ftcida. 

3.  a-Amiuo-acids  are  formed  by  tlio  action  of  irmmonia  upon 
the  cyatihydriuK  of  aldebydes  or  ketones,  aud  aubeequont  hydrolysis 
of  the  sitrile-group: 

H  /H 


+  NH, 


Alftniiw  nlirllc 


CH.CfNH.    . 


Alsolnv 


The  smino-ftcids  pogsees  two  oppoeitc  charnctera;  they  form 
uUCB  with  both  acirU  and  hase^,  and  are  tlierefore  toth  basic  aud 
.Kidic  at  the  name  time. 

Replaccmert  of  the  hydrogen  of  the  amido-groiip  by  radiclea 
tyieldif  araino-acida  of  a  more  complicated  character.     Thus,  like 
lammriaia,  with  ttoid  chlorides  they  yield  an  acid  amide,  in  which 
one  hydrogen  atom  of  the  aiuido-group  lias  been  replaced: 

RC0CnnaHN-CH,C0OU  =  RCQKHCH.C0OH+HCl. 


I 


CorapoiindB  of  this  kind  are  therefore  both  amino>acids  and  add 
amides. 

Amino-noids  in  whinh  the  hydrogen  of  the  amido-gronp  is 
replaced  by  alkyl  ar«  aUo  kiiowu.  They  arc  obtained  by  the  action 
of  amincB,  instead  of  nmmoTiia,  on  the  halogen-substjtutcd  acids: 

(CU,),N|lTTnlU,C  COOH  =  (CU,).N.CH,COOH  +  UCl. 

The  nmino-ncids  undergo  mo«t  of  the  (Iccompo^iCione  oharac- 
terlstic  of  amines;  thus,  with  nitrous  acid  they  yield  hydroxy- 
adda,  just  as  the  amincji  yield  iiJroholK. 

The  same  remnrkublc  tUtfprcnre  of  properties,  occa^oned  by 
ttw  poaitinii  of  the  amido-groupB  relutive  to  the  carboxyl-groajis, 
ia  displayed  by  the  amino-acids,  as  has  been  dcacribed  in  178  and 
183  in  connection  with  thohalogon-Biibstituted  acids  and  hydroxy- 
acids.     The /r-amino^aeidx  readily  jiclr!  anhydrides  (acid  amides) 


»44 


ORGANIC  CHEMISTRY. 


hy  the  eliinination  of  two  mulccu'ee  of  water  from  two  molecules 
of  Mid: 

CO  OH llHNCn,  '         ('0 — HNCH, 


The  ^-amino-actdit  easily  split  off  ammonui,  with  fonnatioit  of 
UDsaCuratMl  acidK.  In  tliiH  wu^,  /J-aiumoprop ionic  acid,  obtained 
from  «3-ioc]opropionic  acid,  is  couverted  on  heating  into  acrjrlic 
aoid  and  ammonia: 

|NH^|CH,C:h|h1-C0QH  =  NH,  +  CH,:CHCO0H. 

Lilte  the  y-bydroxy-acids,  the  ^-amiuo-acida  yield  inner  anhy- 
drideji;  thoaa  aubatances  are  called  iadama  on  account  of  their 
similarity  to  the  lactones: 


r 


Cn,'CH,CH,-CO 


CH  -CEI  -CH  -co 


I      _ 
NBH 


_l 
Oil 


=  H,0  +   I 
•         NH- 


t-ADiluobuij'nc  Mtd 


l^euuB  ot  i-«)>ilBobm;rfc  mM 


The  vslers  of  amiuo-acich  can  be  obtaine<l  in  the  nsiial  way,  by 
dissolving  thR  acids  in  absolute  alcohol  and  treating  this  solution 
with  hydrochloric-acid  ga«  (97).  The  salts  of  hydrochloric  acid 
are  the  primarj'  proiluote  (e.g.,  HCI-NH,*  CH,*CO,C,Hj,  the 
hydrochloride  of  glycocoU  eater),  because  the  ainido-group  in  theee 
eaters  has  its  usual  basic  properties.  The  cstt^ra  themselTea  are 
prepared  from  tltose  salts  by  treating  them  in  aqueous  solution  with 
a  concentrated  solation  of  potassium  hydroxide  at  a  low  tempera- 
ture, and  iniiDcdiatcly  extracting  the  liquid  with  ether.  BviL 
FiSUHKH  has  pro%'rtl  that  these  eaters  are  very  useful  for  thepuri6os- 
tion  and  Hepariitiim  of  Hmiiui-HciilH.  Thiii  in  of  great  importance 
in  the  chemistry  of  protei'dH,  which  are  split  up  into  a  seriex  of 
these  acids  by  the  action  of  acids  or  of  bases. 

IndiTidnal  Vemhert. 

BOO.  OlyfMoU,  or  aminnnf^tic  ncid,  Nn,.CH,.COOH,  can  be 
obuiued  by  boiling  gine  with  dilute  Hulpbnric  acid  or  with  bariam 
hydroxide;  it  owes  its  name  to  this  method  of  formation,  and  toiti 
swcot  taste  (yAtifctJ!,  sweet;  KtiXAa,  g\ue).    It  is  aIao  prepared  front 


hippuric  add,  which  i»  present  in  the  nrine  at  horeee.  and  may  be 
lookeil  upon  us  glj-c-ocoll  in  which  one  of  tht  hydrogen  atoms  ef 
the  amida-group  bus  been  replaced  by  benaoyl,  0,11,00;  hippuric 
acid  haa  therefore  the  formula  C.U, '  CO  -  Nil  CH.COOU,  and,  lik« 
all  acid  amidea,  when  boiled  with  dilute  acids,  spills  up  with  addi- 
tiuti  of  the  «leiiicnta  of  w&t«r: 


C.H,CO[Nn  CH,  COOH  =  C.H,  COOH  +  NH.CH,  COOH. 

OH  [H  BmtalaMid  Oiyooooll 

Hlppiiiic  acid 

QlycocoU  can  be  syntheticatly  prepared  by  the  action  of 
ammonia  on  monochloroacetic  acid. 

Olycocoll  is  a  cpj'stallin©  solid,  and  melts  at  332"  with  decom- 
position; it  is  very  rendily  eolublv  iu  water,  and  insolnblo  in 
abaolnte  alcohol.  Like  many  amtno-acide,  it  forme  a  well-crystaU 
lixed,  blue  copper  ealt,  soluble  with  difflcnlty  Id  water,  and 
obtained  by  boiling  copper  c»rbonate  with  a  eolution  of  glycocoll. 
[t  cn'stallixes  with  one  molecule  of  water  of  crystallisation,  and 
has  the  forraoU  (Nll.cn,  COOj.Cu  -f  11,0- 

Beta'ine,  C,H,jNO, ,  ie  a  derivative  of  irimethylglycoooU;  it  is 
Wild  in  the  juice  of  the  sugar-beet,  and  aeeumulat4?8  in  the 
'nu1a8««8  during  the  manufacture  of  sugar.  It  must  be  looked 
Upon  aa  an  inner  ammonium  ealt, 


i 

u 


(CH,),N-CU,CO 

i'H    Ah  I 


siune  it  is  synthetically  obtained  from  Irimcthylamine  by  the  action 
of  monochloroacetic  acid,  with  elimination  of  HCl: 


f 

mi 


(OH,),y  +  ci-cir,-coon  =  (cn,),Ncivco 

1        o 


ICl 


H 


,Tlits  reaction  is  anuloguu«  to  the  iotiiniction  of  aJkyl  halides  and 
LTliary  amiuea,  yiiilding  the  salts  of  the  ammonium  ba«e. 
BetaTne  fonnis  liirge  crj-staJg  with  one  molecule  of  water,  which 
\U  loeca  at  100'-,  nrwheu  allowed  to  stand  over  sulphuric  arid.    On 
hnliog,  it  decompose*,  with  formation  of  trimethylamine. 

kMany  tertiary  amines  can  be  converted  into  Bubsianccs  with  a 
lUtaUon  unulogQU^toJ.hat  of  hetaino;   that  is,  inner  ealte  of 


^ 


34^ 


ORCANtC  CHEMISTRY. 


STDmODium   baB««.      Theac  corapoandB   have    the  i^nenU   nunic 
betainea. 

Alanine,  or  a-aminopropionic  ttoid,  CH,'CH(KH,)'C001i.  is 
Byntheticallj  prepareil  by  the  Hction  of  mnmonia  on  ff-chloru- 
propionii;  acrid. 

Levoine,  or  a-aminoisobntylacetic  acid, 

(CH.),CH  CH,  CH{NH,)  OOOH, 
rpaulU  iiilong  with  glyoocoll  from  thu  docont position  of  ftlbnmitu  ■<« 
the  action  of  acids  or  alksliB,  or  by  putrefnction.     It  ig  «ynUicti- 
cally  obtained  from  iHOvaleraldehyde-ammoniA  by  the  action   of 
hydrocjanic  acid,  nnd  hydrolysis  of  the  resulting  nitrile: 

/^ 


\ 


(ciy,CH.cH,.o^  on  +  n  cn 


lK)v«l«nt|[!a)ird»<iiiinonl« 

Ln»dn« 
Oxidation  with  man^aneei?  dioxido  and  dUnte  sulphuric  acid  cod- 
vertt)  Ivucinu  into  eurboii  dioxide,  water,  nnd  valeronitrile: 


C.H, -P 
N 


H  -l^tlHj  =  C.H,.  CN  -I-  CO,  +  2H,0. 
H,+  QO 


C,H, 


VHwCOMI, 
J^n.KcoOH  • 


It  is  remarkable  that  in  this  oxidation  a  sabstance  is  obbiim'd 
wliich  does  not  contain  oxygen.  The  Icuciiie  obtaiut-d  from 
albuminfi  in  optically  active;  its  formula  uoiitaias  an  aaymmetrie 
carbon  atom. 

Asparagim  is  often  present  in  sprouting  itcedo;  to  tbeexteutof 
SD-SO-t  in  dried   lupine  seeds.     It  may  be  looked  upon  as  the 

amic    nuid    (163)   of  arainoBUCcintc  acid, 

UQce  on  faydrolyBifl  it  i«  converted  into  aminosnccinlc  ucid 
{mparlic  acid),  COOH  CHCNU,)  CTT/COOH,  whose  stnict.m-  t» 
inferred  from  its  conversion  into  malic  acid  by  treatmeoi  with 
nitrous  acid.  Aspar&gine  prepared  from  seeds  is  BOmetitnoi 
dextro-rotatory,  but  generally  Isavo-rotatory.  The  former  is  sweet, 
tho  latter  tasteless. 

Homologoas  with  asparagine  is  glutamxne,  which  is  also  present 
in  the  aeed»  of  sprontini;  plants.  It  j»  tho  amic  acid  of  <r-amiiio- 
glutftric  acid,  COOU  C1HKU.)CH,  CU,  COUH. 


LYSiSe.  ORNITHINE.  AND  DIMZOACETIC  ESTER. 


247 


Diiunino-ucide  arc  also  obtsiued  by  the  splitting  up  of  proterds; 

thua,    lifgitte,  C,n|,N,0,  is  pruduvud  by  the  action  of  u(?id«  on 

olbumiue.     PutrcfactiuD-bttuUli  dccotnpoev  it   with   formation   of 

I  jKDtomothylcnodifiniino  (16S),  and,  us  it  U  tm  aoid,  it  is  probable 

that  it  has  the  fonniil»  NH,OH,-(CU,),.CU  <^J^^jj,  aud  is  an 

'  ae-dianuDOcaprcic  acid. 

Ornithine  h  the  n<<?ct  lower  homologuo  of  lysine;  it  bai  the 
JonnuU  C,E„N,0,  or  N!f, -CH,  CH,  CH,- CHlNH,) -COOH; 
bj  the  action  of  biiuinriii  it  yield*  putreeciito  or  tetnimethyleno- 
diamine  (162).  Its  structure  ia  proved  by  Kail.  Fischeb's 
ayntlicais  (338). 

Diazoacetio  Eit«T. 

flOl.  0iniTru9  faaa  obtaioed  »  yollow  oil  of  cliarHc-Cemtk  odour  bf 

tb«  action  of  nitroiia  acli)  on  Iho  ethyl  Ptttrr  of  glyMcoll;  this  mib- 

Btancfl  fiiplndes  on   heatiug,   and   has  tlio  formula  L'.IItNtOi.    Tbc 

Dcchod  of  itA  formation,  and  its  oonstitntional  formula,  are  indicated 

tbe  following  e<|unti«n: 

c,H.ooccn,.>ni,  +  nso,  =  cn.ooccnf  n  +  2ir,o. 

Olyonooll  Mdr  ^N 

|.ii  called  diazoQixtic (jter ;  its  constitution  is  inferred  (ram  the  fact 

;  Its  two  nitroKeu  atoms  are  replaceable  by  two  monovfllent  (groups 

'  elemenu:  thuti,  on  heating  wtCb  water,  it  is  converted  Into  tbe  etbyl 

^«ator  of  glycollic  acid; 


C,njOOCClI<^ 


+  5ii  =  f,H,ooc-cn<gjj  +  N^ 


ta  thia  way  it  yields  monocliloroaoeiic  e«ter  with  bydrocldorlc  acid 
■ad  di-iodoaootiu  enter  with  iodiuu.  The  hydrogen  atom  of  tho 
CHNi'fcroup  is  replucuablc  by  niotala,  medium  diwolTing  iu  diazoaeetic 
teter  with  eyolutian  of  hydrogen. 


M  atom, 

jCvaBKn.3u  «ESM»4£«VMaanneHM?MiaBMC3L*aiL, 

tm-  'Mou^  -Mum.  "auc  -m  jyaai  ^  mc  bcx.    T^  aicrac : 
maiiaM.  ndbuie  jns«  ':a<t«irBir^  ^w  auMOOL  jt  attwrr  \iJiLaaL.  wj^ 
liiiii'iMi  ifrjiiiii"   i_7  iiMi   Miif  imTi  w  ifti   iiiif  ii'wi  ii'i 

^jivsak.    »    »    •nirtiBSeai.  aHurTOMiB  «i-iw»ii»: 
X  fiMMCvvi  3ta^7  21  wKitr.  'ins  t^tt  UKwrj  j&a-  «iB3ueGe  -c:7>af 
w  vmtmt  ic  ^IV-lai*^,    W  -nwiTrifTTii'TTTn  m  -aiirnryw  if  iwcTii  ii 

^fc  ';ae  aJuflrr-M*.  «b*a.  M  toe  f-^.^uKaw.  -'.f  %  £:*>se  tafrrx.     Ox. 
3.  MW.rt3£<%  vf=2.  TU  KaoM 


H     H 
O     O 


=      CB,OH-COOHl 


H.  O 


MS 


D/f(£TOffES. 


»49 


DiketoQet. 

203.  The  dikelouea  contain  t-wo  carbonyl-groupn,  whose  relative 
pogitiouB  Jetermiue  the  methods  of  prppanitiuu  uf  thest  coin- 
jiounds,  and  tlicir  propertivB.     1 :  2-l>ikotonc-a  arc  kiiowu  contain- 

IV  19  1 

ing  the  group  —CO  ■  CO—;  1 :  3-dikotoneg  with  —CO  ■  CH,  CO— ; 

l:4-diketone«with  — CO-CH,CH/CO— ;  and  bo  on. 

I :  "t' Dikftoues  cannot  he  obtained  by  tliB  elimination  of  clilorine 
from  the  acid  chlorides  by  the  action  of  a  metal. 


R  ■  COlCl -l-Na,  +  CilOC  ■  R, 


r  a  method  which  naturally  Bnggraba  iteclf.     Their  propiratton  has 

I  to  be  effected  by  the  action  o.f  amy!  nitrite  and  a  little  hydro- 

I  c3iloric  acid  un  a  ketone,  whereby  oiie  of  Che  CH, -groups  La  coa- 

I  Tert«d  into  C=NOn. 

I  Th 

i  dUi 


E-CO-C 


U.J.R' 


HCO 


C-E' 
NOII 


These  connpoundM  arc  called  isonilrosoketoneii.  When  boiled  with 
dilute  sulphuric  acid,  the  oximc-group  is  split  off  ae  hydroxyl- 
amine,  vith  formation  of  the  diketone.  The  iefoaldehydetf 
which  are  boOi  kutouea  and  aldehydea,  and  contain  the  group 

— (-0-C^..,  cui  also  1)0  obtained  by  this  method. 

Diaeeit/l,  CH,-CO'COC"I!,,  (tan  bo  preparfid  from  methylethyl- 
ketone  in^the  way  d^Kcribed  above.  It  is  a  yellow  liquid  with  a 
punguut.  sweetish  odonr.  and  is  Bolublo  in  water;  its  vapour  liiia 
the  Humc  uotour  ais  uhlurinu.  DiaceLyl  buUs  at  88%  and  lute  a 
fpeoilic  gravity  of  0-BT3  at  30°.  Ite  behavionr  is  tliat  of  a  sub- 
tctaneo  conttuning  two  oarbonyl -groups;  it  adds  ou  aHCN,  yit^lds  a 
mono-oxime  and  a  di-oxime,  etc.  The  two  carbouyl-groupg  are 
■hown  to  be  next  to  each  other  by  the  action  of  liydrogen  perox- 
ide, wliich  coDTerte  it  quantitatlTely  into  acetic  acid : 


CW -CO— 
-h   OH 


CO- on, 

OH 


aCH,COOH. 


»So 


0RG.4NK'  CHEMISTRY. 


iiS'lh'lulouM  can  be  prepared  by  a  condenmtion-method  di»> 
covered  by  Ct.aisek,  whic^h  w  of  general  appUmtion.  He 
employs  sodium  ethoxidr  ae  the  cnndenBing'Sgent.  un  ttdilition- 
product  Wing  foitniid  when  thu  ttubetunoo  is  brought  into  coutoct 
with  an  oetor: 


0(',H, 


=  RC^OC,H,. 


This  addition-product  ib  thun  treated  with  a  ketone  R'-CO'CH,, 
whog«  niothyl-group  reacts  in  fniob  a  w»y  ae  to  oliminat©  two  mole- 
culos  of  alcohol,  with  fommtion  of  u  condenHutiou-product: 


n/l 


ONa 


^  '^\|o[-:h:  +  H  CH.CO.R'=B.C^gy.co  ■R^+aC.H,On. 


On  treatment  of  this  oonnpoond  with  a  dilate  acid,  the  godium 
atom  w  replaced  by  hydrogen.  This  might  ba  expected  to  produce 
a  compound  ('nntaining  n  hydrosyl-groiip  in  union  with  a  donbly- 
linkr^l  rarliim  ntom:  it  liati  b«4in  alicudy  mentioned  (136)  that 
compounds  of    this  type  aro    as   a    rule  unitAbto,   the    group 

Oil 
— C=CII —  passing  into  — CO — CH, — .     This  mlo  IioWb  good  in 

on 

the  present  iuBtancc.  KtJ=Cli'CO- R'  yielding  a  1 :3-diketone, 
R  CO— CU— CO  it. 

Anottter  ii]«thod  for  the  preparation  of  l:8-diVeU)DC8  is  the  action 
of  acid  cli1ohde«  on  theeo<liUTn  ooinpoandsof  floetyl«in«  bomologuee : 


CH,.<CTH,».r=rlS«+_CI|fK'.Cll.- 

SodlD-n-oia;  lacctyltne    Acctft  cbloNde 


.CH..C0H0«'0aiC-OO.CH,. 


By  treating  lliia  ketooo  with  oonceatratod  Hulptiurio  acid,  water  ta 
added  oti,  and  the  desited  diketone  obtained : 

0H,-(tJH,).-C=i;-CO-UH,  =  CH,.(CH,),-CO-CH,CO-Ca,. 
+     0   H, 

Thc«o  diketonee  have  a,  weak  acidic  character,  their  diMOcia- 
ticm  constants,  which  hare  been  determined  for  some,  tncludin| 
aceiyhcetow,  CH,  CO'CH,-CO -CH,,  being  very  small.  The? 
contain  two  ll-»toms  replaceable  by  metalB — those  of  the  methy. 


4 


DJKETONES  AND  HALOGEtTSUBSTllVTED  ALDEHYC 

'huv-^Ttntyi  lietweeij  two  negative  earbonyl-groups;  for  If  it  were 
ithc  otbvr  favdrogeii  utonm  which  (u>uld  he.  thim  exch&ngHl  for 
l-mctJilii,  there  ie  uo  rciuoii,  since  ihcy  art  oi  i>qual  valtic,  vhy  two, 
[and  ouly  two,  aliouM  bo  rcpluucablc 

AtxlgJacetone  is  obtaiaod  by  t}ie  coodeDAalion  of  ethj]  acetate  and 
acetone  in  the  msnner  described  abovt-.     It  is  a  coloiirlesa  liquid  of 
aKrwable  odour ;  B.P.  187',  bd.  gr.  OitT»  al  IS'.    Wbou  Iwilcd  with 
water,  it  upliu  ii}i  into  acetone  and  aeetio  acid,  tlds  rvaction  anordiiig. 
another  example  of  the  ioatabilitv  of  oompoiinds  coutaining  a  carboa' 
aiocn  loaded  with  n«t(Ktive  g roupi. 

Aror>ng  the  xsiiia  r-t  occtylneetono  may  ht  ncotioiwd  the  copper 
sail,  (CtfliOOtCti.  which  is  iipartrigly  soluble  in  water:  a»d  the  vola- 
tile aluminium  salt,  (C|HiO,)iA].  By  n  determination  of  th«  vapour 
density  of  this  compound.  Cohu»  has  nhown  that  the  alumiaium 
atom  la  triralent.  Many  of  theae  saha  niw  insoluble  in  water,  bat 
soluble  in  benzene,  clitoroforui.  or  other  organic  aolTenta;  thia  makn 
itdoublTal  wbuthcr  they  Ar«  truo  salts. 

As  «  irpe  of  the  I'.-i-tlikeloices  may  be  cited  acelonyUtcetoue, 

;H,CO-CH,-CU,-CO-Clt,,  the  preparation   of  which    wiU   bo 

fdeecribed  later  (236).     It  is  s  oolourtoBa  liquid  of  agreeable  odour; 

B.P.    193%  ep.  gr.  0-U70  at    n".     Acotouylacatone   and   other 

] :  4-diketonea  yield  a  variety  of  eompoundg  coutaiuiiLg  a  cloeed 

[chain,  which  «ill  Ije  treated  of  in  391-393. 


Halogen-iabstituted  Aldehyder 

804.   Chhral  or  trichloroacetaldehyde,  CCI,- C^q,  is  of  ^reat 

' importuiKW  from  a  medical  Btaitdpoint.  With  one  molecule  of 
iriit«r  it  forms  a  cryslallino  coniponud,  which  i«  used  u  a  Boporilic 
under  the  mime  chhral  hydraif,  and  is  teohnicslly  prepared  by 
Mtnrating  ethyl  aleohol  with  chlnrino.  The  alrobol  must  hv.  aa 
free  from  water  ait  posHJble,  and  the  chlorine  mnflt  he  can>fully 
dried.  At  first  tht  reaction-mixture  is  artificially  cooled,  hut  after 
a  few  days  the  process  becomes  leas  energetic,  and  the  tempoiature 
isdowly  raisod  to  Oi)-,  and  finally  to  100°. 

This  reaction  miiy  bo  explained  by  assuming  that  the  alcohol  JB 
firit   oonvert«d    into   aldeimie,   which   is  then   transformed  into 

tlKvtul,  dichloToacetal.  and  trichloroscotal ;  the  Inst  compound  is 


^  -"r*c: —  ■     x'-.l 


t- '»■...■-. 


■^ ..-  .   ^ .hi     _^_ 


-rf;  T^^,-, 


«.—   *    "SW    »:     :    -^     --    ■-- 


«  ■      j'i- 


.>  *  .'-4.  .  '.-r/ -.-.  :'>^   ■   ti     ~;,.i^,'~  "r'i '"^ "»."  ;.~T!  ■*",■_!  Iirr 


CHLORAL  AND  HALOGEN-SUBSTITUTED  KETONES.         253 

On  account  of  ita  parity,  chloroform  prepared  in  this  manner  is 
preferred  for  pharmaceutical  QBe. 

The  formation  of  obloroform  from  chloral  by  the  action  oC 
alkaltiie  liquids  suggested  the  use  of  chloral  aa  a  soporific,  it  beio^ 
eipected  that  the  alkaline  constituents  of  the  blood  would  decompose- 
it  with  the  formation  of  chloroform,  thus  generating  the  latter  in  the 
body  itself.  Liebbkicb  showed  that  chloral  has  in  fact  a  soporific: 
action,  but  more  recent  investigation  has  proved  this  to  be  independ- 
ent of  the  formation  of  chloroform,  since  the  chloral  is  eliminatedl 
from  the  system  as  a  complicated  derivative,  urocbloralic  acid. 

Halo^en'fnbstitiited  Eetonei. 

S05.  An  example  of  this  class  of  compounds,  dichloroacetone, 
OH«Cl-CO-CKiCl,  was  mentioned  in  198.  Variously  substituted 
ketones,  some  of  which  have  a  powerful  odour,  are  obtained  from 
acetone  by  direct  ohlorinatioo. 


AISEHTSE  ASD  EEXONS  ALCOHOLS  OS  8TT0AS.8. 

206.  The  term  ''engarft"  fomifiriy  includcii  comi>ounJB  con- 
tainiDg  six,  or  a  lunltiple  of  six,  csr1>oii  atoma,  and  hydrog«u  and 
oxygen  in  'the  ]>roportioi)8  to  form  water.  To  this  they  owed  th« 
iiiimc  carbiihytlrates.  Whvii  boileil  with  dihiU"  iiciiis,  thp  mignn 
cotitiimiiig  a  m»Uij)lo  vt  bU  carbuu  utoma  Jetiomimst',  taking  op 
the  elements  of  water,  with  formfttioa  of  carboliixlniles  containing 
six  carhou  atoms : 

The  Utter  liad  the  general  name  monogatchariJei,  w)ule  those 
containing  »  X  6  ciirbuii  utouis  wero  called  polytatxharide*. 
Among  the  monosucchurideii  were  grupo-eugur,  or  glucom,  and 
frait-Bflgiir,  or  fructose,  both  with  the  formula  C,il„0,;  the 
polvMicchiiridi'H  ineltuliHl  rnno-ttajmr  niid  milk-nugnr,  with  the 
formiiU  C',,ir^O|,,  ami  sta.rfh  and  eellulnse,  {C',II,|,Oj)x,  of  on- 
known  molecular  weight. 

]\Iiiiiy  itinnoHiccliaridi!K  containing  six  carbon  atoms  have  been 
prepared  since  ISfiTi  chiefly  thruugh  the  n-searrhes  nf  Emil 
FiscnER,  and  ecveral  new  enceharidcs  containing  more  or  lc<s8  thitn 
Bis  c«rbon  Btom*  have  also  been  diseovprod.  The  conetitntion 
of  most  of  tbese  tM>mpOHiidK  has  been  determined  with  great 
certainty,  so  that  a  new  light  has  been  thrown  upon  the  chemistry 
of  the  sugars,  and  tiic  definition  of  these  subatanccR  from  a  chemioU 
standpoint  bae,  therefore,  undergone  confliderablc  modtScation. 

Tkt  monoiocchari^ee  ai-e  aldehytle  aleohole  or  teiortt  aUxhclt 
containing  ott«  or  more  htjdroxyl-groupSf  one  of  which  in  <iirectiy 
linireii  to  ti  eoTbon  tUovi  m  uttioii  mth  earhonyl.  The  characteriBtic 
gronp  of  t)ie*e  compounda  is  therefore  — CnOTI — CO — . 


NomeDclaturD  and  OentraL  Fropertiei  «f  the  llouoses  and  thair 

DerivatiTes. 

807.  Tlie  monoBtooIiandos  have  now  the  gcncrul  namo  monoits: 
when  they  are  nldohydes  they  are  culled  aldoses,  and  when  ket«n«8, 

354 


MONOSES. 


*55 


hioset.  The  number  of  carbon  atoms  in  the  molecuta  is  indicated 
b;  their  namcB:  thne,  pealose,  kezose,  heptwe,  etc  To  denote 
vbetheT  a  compoand  is  an  aldehyde  or  a  ketone,  tbe  pretix«B 
"aldo-"  and  "keto-"  respectively  ar*  oaed;  as  ald^kexosc,  helo- 
fiBxcse,  and  so  on. 

The  polysaccharidee  aro  now  called  polynte'.     When  they  may 
bo  regarded  as  dL*rived  from  two  monosu  molecules  by  the  elimiua- 
tioD  of  ono  uiolcculo  of  water,  they  arc  called  Imaea;  thna,  htxa- 
,iioaes  when  they  are  formed  from  two  molecules  of  hexoiie.     The 
'polysaccharidcsderived  from  three  monoae  molecules  by  tb*  elimina- 
tion of  two  moleculea  of  water  are  called  trioses;  as  hexotriose,  etc. 
Like  aldehydes,  the  aldoses  are   nonverted  by  oxidation  into 
moiKiliaHiu  acids  coutainiug  the  suiae  number  of  carbon  atoms, 
the  puntutieB  yielding  the   monobasic  ptnlomc  acide,   and  the 
liDxowis    yioIdiuK  tb*  hcxonic   adds,    etc.      The   oxidation    can 
be  curried   further;   for  thu  general  formula  of   an  aldose  is 

CH,On{CnOH)„-C<"  (309),  and  the  group  C1I,0U  can  be 

oxidized  to  carboxyl,  yielding  a  dibaEic  acid  containing  the  eamo 
number  of  ■carbon  atoms  as  tJio  alioeo  frnm  whicb  it  is  derived. 
On  oxidation,  the  ketosos  yield  acids  containing  a  Bmaller  namber 
of  carbon  atoms. 

On  radnctinn,  the  aldoses  and  ketoKB  take  up  two  hydrogea 
atoms,  with  fornmtion  of  the  curreepondtng  alcohols;  thus,  hcxose 
yields  a  kexahydrie  akohol,  and  pentose  a  pentahydric  alcohol  {309 
and  Sll). 

208.  Fonr  rcactionx  are  known  vhich  arc  charaoteriutic  of  all 
monoges;  two  of  these  they  poseeiia  in  common  with  the  aldchvdes 
(116). 

1.  They  reduce  uii  amwonincal  silver  solution  on  warming, 
forming  a  metallic  mirror. 

2.  Whon  warmed  with  nlknlitt,  they  give  ^  yellow,  and  then  a 
brown,  eoloiiratinn,  and  ultimately  resinify. 

3.  When  an  alkaline  copper  solution  (Feuuxq  or  OsT,  192) 
is  heated  with  a  nnlution  of  a  mnnose,  reduction  takiM  place,  vith 
formation  of  yellow-red  Muboxide  of  copper. 

4.  When  a  monoeo  id  heated  with  oxcew  of  phonylhydTaiino, 
C,H,  •NU-NH, .  indilntoncetin-onid  Rolntion,  a  yellow oomponiid, 
ciystalliziug  iu  Uno   needles,  is  fonned;  substances  of  this  typ« 


a^ft 


ORGANIC  CHEMISTRY, 


aro  insoluble  in  wuter^  and  are  called  osatotus.     Their  formntioa 
may  be  explaiuuil  in  the  following  way. 

It  iraa  laL-iitiuued  in    206   that  the  sugars  are  characterised'^ 
by  Uieir  containing  tlic  Rroup  — CflOLI— CO — .     The  action  of 
pheDyIhT<)raziDe  on  n  carWnyl-group  hae  been  already  explaiof 
(113);  water  is  eHmiualeil,  aud  a  liyilrazoue  i^  fonaed: 


ilo 


+  i-[,]y  •  KiK'.n,  =  c :  N  •  Nnc,H,  +  n,o. 


A  seooDd  molecule  of  plienylhydrazine  then  reacts  with  tlio  group 
■ — CHOH — ,  Troin  which  iwo  hydrogen  aloma  are  eliminated,  the 
molecule  of  phenylbydruziue  being  ^plit  up  into  auuuoniu  and 
aniline: 


cn,-Nir-NH, 

Phuiiylliyilraxiiio 


-I-     H    H 


Antliu* 


The  removal  of  two  hydrogen  atoms  from  the  pronp  — CHOTI — 
converts  it  into  a  rarbonyi -group,  — VO — ,  with  which  a  third 
molecule  of  phenylhydrtuiuc  rtiacts,  forming  a  hydrazone,  so  that 

cHon  c=rX-Nnc,H, 

tho  group     t  is  converted  into   |  ;  this  group 

CO  C  =  N-NUC,n, 


is  eharacierigtie  of  (he  omtones. 

The  osazonos  dissolve  in  wator  with  difficulty,  and  tliis  property 
makea  them  of  great  service  in  the  separation  of  the  mouo»es,  since 
thttsoeubBtancea  are  very  soluble  in  water,  and  crystallise  with  great 
difficulty,  o8pei:ially  in  prennnrc-  of  fuUt»;  eo  thnt  their  purification 
by  thia  method  Is  often  impracticjvble.  liy  moans  of  tho  epanngly 
soluble  osaxoneg,  howovor,  thoycJin  bo  separated;  thceo  are  readily 
obtained  in  the  pore  stale  by  cryetallizatiou  from  a  dilate  solution 
of  pyridine  (386).  Moreover,  the  identity  of  the  monoac  can  be 
OBtabliahed  by  a  determtnation  of  the  melting-poiat  of  the  oaasom 
thuB  obtained. 


Comtitntion  of  th«  Modom*. 


209.  It  will  bo  ehowQ  tntor  that  tho  congtitation  of  &I1  tbcl 
monoKos  folIoKs  from  th»t  of  the  ftldohnxoWB,  whoeastrocturo  may' 
be  dedncetl  in  the  following  way. 

1.  The  aldohesoBPs  have  the  molecular  formnia  CJI„0,. 

2.  Tho  aldohexoBes  an)  aldohydco,  and,  tli«reforo,  contain  ft 
carbonyl-group  iu  tho  moleculo.  This  follows  from  the  fact  that 
they  »how  tho  roiictiong  peculiar  to  aidohydos;  that  they  aro  con- 
TeiUA  by  oxidatiou  into  acidH  coDtaining  tho  same  number  of 
C*aloii]g,  and  by  reduction  into  an  alcohol;  and  that  tlioy  have  the 
power  of  fonniug  a<idition-prodHctfl  with  liydrocjuuic  acid. 

3.  All  kcown  hexoses  contain  a  normal  chaJD  of  six  carbon 
atoms,  since  they  can  be  reduced  to  a  hexahydrio  alcohol,  which, 
on  farther  reduction  at  a  high  temppratiirL>  with  hydriodic  acid, 
yields  a-aecoudary  hoiyl  iodide,  CH,  ■  CII,  •  CHI  ■  CH,  •  CII,  •  CH,. 

Tho  cooslltDlion  of  this  todido  in  inferred  (rom  tbc  tact  that  it  oaa 
be  coiiTOctcd  into  no  alcolio),  which  on  oxidatiou  yields 
CH,-CH,.CO.CII,-Cn,-CH.-. 

for  oa  further  oxidntiua  this  la  converted  into  n-butyric  and  nceUe 
adds. 

4.  The  hexoses  hare  five  Lydroxyl-groape,  siuce,  wheu  heated 
with  acetic  anhydride  and  a  small  quantity  of  sodium  acetate  or 
line  chloride,  they  yield  penta-acetyl-dcriTatiTee. 

These  factii  indicate  thv  existence,  in  an  aldohezose,  of 


a  normal  carbon  chain,  C— C — C — C — C — C; 


C— C— C— C— C— c  < 


C— c— C— C— C— c^ 

0H<!>nbH<!>n&ii 


O' 

H 


an  aldehyde-gronp, 
fire  hydro xyl-groupB, 


Tliere  are  six  other  hydrogen  atoms  in  the  formula  C,n„0,,  and 
these  will  fit  in  with  the  la«t  scheme,  if  the  C-atoma  of  the  chain 
are  singly  linked  to  each  other;  the  formula  of  an  aldohexose  will 
then  bo 

CH.— CH— CH— CH— CH— C<§ 

^H     6U    6h    6h    (!)H 


J58 


ORGANIC  CHEMISTRY. 


In  these  formuls  &  somewhat  arbitrary  assamption  has  boeu 
m»A9  as  to  the  distribution  of  the  hjdroxyl-groups  ftnd  liydrogQn 
atoniB  relntive  to  the  carbon  atoma;  it  ia^  however,  in  aocordanoe 
vith  the  rule  (13&J  that  a  carbon  atom  caiiuot  usiully  be  linked 
to  more  than  one  hydroxyl-group.  A  more  oonvincinjf  proof  of 
the  fact  that  the  muuosiA  <Io  not  contain  two  hydroxy! -groups  tn 
unioa  with  the  mmo  carbon  atonic  may  bo  deduced  from  tbo  fo]> 
loving  consideration*. 

When  a  hexoBc,  0,H„0, ,  is  redace<J  too  hexahydric  alcohol, 
C,II,,0,,  only  two  hydroj;en  utonm  are  added  on,  and  this  addition 
most  take  place  at  the  doubly-liukud  oxygen  atom,  since  the  carbon 
ehuin  remains  iinbrokou.  If  the  hexow  oontajcs  two  hydroxyl- 
jrrotipH  in  union  with  one  carbon  atom,  the  Mune  miut,  therefore, 
hold  good  for  tho  hexahydric  alcohol  dorived  from  it  C^>mpounda 
eontnintng  a  C-atom  in  nnion  with  two  QH-groups  readily  uplit  off 
wntor,  with  formation  of  aldehydes  or  ketones;  they  also  possois 
most  of  the  prnpcrtiee  characteristic  of  these  aabstancea  (804)- 
Tho  hexahydric  alcohols,  howovi-r,  luive  an  cxclainTely  alcoholic 
^K  chaructor,  and  do  not  exhibit  any  of  tho  reactions  pecnliar  to  the 
^^  aldehyde*  and  ketones.  It  follows  that  tho  hesahydric  alcohols, 
I  and  hence  tho  hoxoMS,  cannot  contain  two  bydroxyl-gronpa  ItDked 

I  to  a  single  carbon  atom. 

I  The  possibility  of  three  hydroryl-groops  being  in  union  with 

i  one  carbon  atom  is  also  excluded,  siuco,  when  the  prodnction  of 

E  a  compound  with  such  u  ^ouping  might  be  expected,  water  i> 

^^      always  split  off,  with  forautioD  of  an  acid  (88): 


0H| 
— COiH 

TOH 


The  monosM  have  none  of  tho  propertiai  whioh  distinguish  acids: 
when  in  aciacons  solution,  they  do  not  conduct  the  electric  current; 
whereas  the  dissociation  constant  for  an  acid  containing  so  many 
OU-groupB  should  be  considerably  higher  than  for  a  aatarated 
£stty  acid,  such  as  acetic  acid  (183). 

Wilh  calcium  and  stmntiuin  hjdrozides,  and  other  bases,  the  car- 
bobydratea  form  oompounda  callad  aooaAaratst,  whiob  are,  therefore, 
to  be  looked  upon  as  aloobc^ates,  Tb«y  are  decompoaed  by  carbouia 
add. 


TntOOS  OF  fORMATlOS  OF  THE  MONOSES. 


*5< 


From  what  has  been  raid,  it  will  bo  aeon  thut  tho  constitution ' 
cf  tho  sldolujxoeeti  csuuot  bti*  other  thaii  t)Lat  given  ahoro,  and, 
einc«  the  same  method  of  jirixif  \&  applitrablc  to  each  member,  thoy 
must  all  hare  the  xamo  constitutional  fnrmulii,  and  are  therefore 
etcrooisomors.  This  ia  duo  to  the  presence  in  thi>  raolecule  of 
ujmmctric  carbon  atoms;  un  .ildoliexOHo  has  four  such  atome, 
indicated  by  asterisks  in  the  formula 

Cli^OH-CUOUUHOII-UUOH.C^HOU-C^. 


lletb«U  of  Forauition.  of  tbc  f4l)B0MB. 


210.  1 .  From  the  polyofws,  by  hydioljais;  thnt  is,  deoomposi- 
tion  with  addition  of  WHt4<r  (206). 

2.  From  the  correnpondiug  alcohols,  by  the  action  of  oxidiz- 
iog-a^nts,  such  as  nitric  acid,  la  this  way  arabitol,  C,lt,.0^, 
yields  arabinofie.  (^sll,^0g;  sylitol  yields  xyloecj  mauuitol  yields 
man  nose,  et«. 

Wliea  glyoerol  is  carefullr  oxidized  mth  nilrio  acid,  or  trjth  bro- 
mluenndcniutifl  lodx.  a  syrupy  liquid  i.>t  oblained,  wliicb  slioirs  ilia 
(our  rcactiorui  glrva  on  p.  355  for  I  be  monoMs  ;  it  is  called  glyctme. 
It*  osaxoue,  fflycerotojom, 

CII.OH 

6=NNH-C,U. 
H 

crrslalhzctt  in  yellov  loeiTM,  nieUiog  nt  131°.  Olycorose  |ft  dihydmxjf 
aettone,  CH,OH-«iCl!,On,  (w  Is  prove>l  by  ih«  eyanhydrln  syn- 
(he^  (IM,  8],  by  lucaus  of  which  tritiydrozyisobutyho  acU, 


ou,ou-C-cn^H, 

COOH 

Is  obtained.  The  siructure  of  this  acid  follows  Trom  its  reductioo  to 
Isobotyric  aci<I.  In  aooonlAnoe  with  the  nometiclsturo  already  indW 
c*ted,  f;lyoerose  is  a  tritite. 

WhoQ  lead  gljccrate  is  oxldixod  with  bromine,  tbe  product,  besJdet 
•iihydroxyaootono,  ooDtalns  glyocraidubydo;  tho  presouce  of  tbi«  sub- 


i 


s6o 


ORGANIC  CHEMISTRY. 


U&ae*  Is  i)rov«d  bjr  ii«  fomiDg  ft  ciTStftllizod  ooDdcDsatioa-prodtict 
with  pblorogiucioul  (SU) : 

o.u,o,  +  M'.H.O,  =  C,J1„0,+  DA 
Oljnwr-       ?iiioro- 

KliMjlt*      Blucuni 

Dib]rdn>xyac«toi)Q  does  noL  yiold  a  similar  oxidatioa-prodiict. 

Glyoeraldabyde  can  bu  ubtmiied  ia  tbe  pure  stue  by  tivaiing  ih» 
«cutal  of  ncrol«Tii  willi  n  dilate  solation  of  potossiam  pcrmaRsnnatn 
(117,  ij,  and  removiug  tlie  two  — OCIIt-groaps  of  llio  occ'tal  bjr 
means  of  diliito  Bulphnrio  add  (lit.  £).  *"- 

U'h«n  sorlK»«-biu:t«rla  src  culiivnted  in  a  soluUoii  of  (^yoeral.  th« 
Snal  protluot  oblainctl  by  tlio  action  of  iho  Atnnsphcric  oxy)[eii  is 
diliydraxyacctoue.  Tbew  baoteria  oaii  oxidiw  otlier  moDoocs  lo 
kdoees. 

3.   ProRi    bromo-componnilB    of  aldehydes,    by   exchange    of 
bromine  for  hydroxyl,  whiub  can  be  effected  bjr  cold  boryta-witter. 

In  this  miuiner  thft  niniplest  member  of  the  BO^urs,  ffti/eoiU»Ubh]/d» 

WJ  11 

CH|OU-C"     tn  «bt«iti«l   from   inotiobromonldoliydv.   aif,Br-OQ;  It 


Bhovrs  All  the  r«actiona  of  tlio  monom. 

TttD  addition  of  bromine  to  acrolein  i.W)  yields  CH.BF-CFTBr-C 


B 
O' 


vlticb  I»  converl^d  by  tlia  action  of  baryta-  water  ioUi  giyoendddtyde. 

4.  From  forraoldehydo,  by  the  action  of  lime-water  (aldol 
comieiiHation).  The  crude  coudeusation-produet,  called  foimoso, 
ia  a  Hvreet,  syrupy  HubaUnce;  it  conaists  of  amixtureof  compotinds 
of  lilt'  formuU  C,1:I„0,.  In  this  reaction,  six  molecules  of  form, 
aldeliydo  undergo  lite  itldol  condensstimi  (115): 


H,CO  +  iICO  +  UCO  +  HCO   +   IICO   +  HCO  = 


By  the  aid  of  sunligbt  and  moUturo,  plaii(s  sro  abls  to  connrt 
tbe  carbon  dioxide  of  the  Atmosphere  into  siarcb.  a  polyoM  of  itio 


Bazykr  liMtuggeM»d  that  the  CO.  1«  tint  iwIucmI  U>  rormaldelirde, 
0H/>,  ffhiflh  Modenses  to  a  mouoae,  the  latter  b«ii)g  tboii  converted 
into  tbe  polyose.  march. 

BenTHRUfT  h.is  obtiiiaed  sitbal&noos  of  llio  n&ttm  of  carboliydrat«a 
by  tb«  ftctioii  or  a  silviit  elviatric  dJGclmrge  oti  a  mixLtire  of  oatboD 
dioxid«,  ourlMD  monoxide,  aud  hydroKeu. 

A  hoxom;  can  iilso  ha  otituinttd  from  glyceraHehjdo,  two 
^(noleciilos  of  wliich  yield,  by  tbo  aldol  coiidensutiou,  one  molecule 
the  hoxosc.  This  boxoso  vs  called  aerote,  on  account  of  its  rela- 
lioii  to  Hnrolein,  from  which  glyccmldohydo  can  bo  obtiiined  by 
^inrlliqil  .'i.  Acmse  is  a.  constituent  of  forinose,  and,  like  all 
Bbotupounds   jiri!parod  by  purely  chemical  syntheBie,  is  optically 

^^^D.  A  very  Lmportant  geaenl  method  for  l.he  cooversioiL  of  an 
aldoso  int«  another  contuiniug  one  more  carbon  atom  in  tlie  mole- 
cule is  the  formation  of  nn  additiuu-product  with  bydrucyanto  auid. 
An  aldobexose  yields  ik  cyanbydriii  which  h  convvrted  uu  hydro- 
lynB  into  a  monobasic  acid  containing  soren  C-utums. 

H   CH.OH  -CnOU •  CHOH -f HOH  ■  OUOH ■  CHOH  ■  COOU. 

■       12  3  4  5  6  7 

HSCho    ^'-hydroxy] -group    easily   reacLii   with    the    carboxyl-groap, 
Hjbrmiug  a  lactone, 

H     CH,OH  •  CHOH  •  CHOH  •  CH  •  CHOH  •  CHOU  •  CO. 

k       -  I 6        - 

/N  itquwus  aoiuiion,  th«i«  iaelttnet  can  At  roduetd  hg  Mdiutn  amaU 

^«MB  io  tke  oorrefponding  aldthyi»t,  ilie  aldmes. 

^H    The  greiit  importsnci!  of  this  itj'nthesis  oousiatii  in  the  theoret- 

^|pd  pOBtibility  of  obtaining  from  th<<  lower  mcmbHrx,  stvp  by  utep. 

^nldoAcfl  irith  uuy  deiiired  numWr  of  ('■atumE  tu  the  mulucule,  by 
repeated  application  of  the  cyuahydriu  gyutbcAiu,  and  rvductioD 
of  the  lactone  thug  oblnincd-  In  this  manner,  it  has  been  posgible 
to  prepare  ««wo««,  with  nine  C-ntomR,  by  conveniion  of  an  aldo- 
hexoao  iuto  a  heptonie  acid,  whoste  lactone  can  then  be  reduced  to 
s  hvptost^  This  compound  can  be  i;oiivcrlL-d  into  aa  octote,  and 
latter  into  a  nonooo,  by  thu  eamu  proccas. 


««2 


ORGANIC  CHEMISTRY. 


I.     UOHOaEB. 

Fentoieft. 

211,  A  reference  has  uJready  been  made  to  the  bioscs  and 
trioees  (207).  Tetroscs  can  bo  obtained  by  the  oxidation  of  pent-y 
onic  acid,  in  the  form  of  its  raJcium  Halt,  by  moaiis  of  hydro^ 
peroxide,  a  small  quantity  of  firric  acetate  being  used  as  & 
,  catalytic  agent: 

CHjOHCHOHCHOHCHOHCOOH  +  O  - 

raDluDlcacId 

-  cH,oirciioiicnon-cfJ  +  oo,  +  h^o. 

T«tt(ue  U 

Also  pentoses  coii  be  obtained  fmrti  hexoses  by  this  method. 

A  nxunbor  of  different  pentoses  have  bet'ii  i<Ien1ificd;  of  th« 
arabinme  and  zylos^,  both  of  which  are  present  in  many  plants 
polyoses,  called  peniosnns,  may  be  considered. 

Arabinose  can  be  prepared  bj'  boiling  giim-nrabic  or  cherry- 
gum  with  dilute  acidjs.  Xifhsc,  or  ivnodsuyar,  can  be  got  in  the 
same  way  from  bran,  wood,  straw,  and  other  substances,  especially 
the  ^lella  of  apricot-stones.  Arabinose  and  xylose  can  be  prcpar 
from  any  plant-celb  which  have  been  converted  into  wood,  andl 
wluL'h  [>ossese  the  roaollung  of  liguin  (230).  The  racetnic  modi- 
ficatiou  of  arabinose  is  present  in  the  urine  of  patient*  suffering 
I  Irom  thf  disease  knuvvn  aa  pentosuria. 

AnilMnose  forma  well-defined  crystals,  melts  at  160",  and  baa 
-  a  sn'cct  tatste.  Ite  osazoric  melt^  ut  157°.  Xylose  also  cr>'staltizce 
'  well,  and  yields  an  osajEonc  which  melts  at  1()Q°. 

Arabinose  and  xylose  are  aldoses,  and  haw  the  same  formula, 

CR,OHCHOH-CHOH-CHOH-C^. 

This  constitution  is  proved  by  their  conversion,  on  gentle  oxida- 
tion wiifibmminp-vrater,  into  nmfc»iif>a/-iW  and  njl^c  aciti  rvspc-ci- 
ivdy,  br^th  of  which  have  the  fommla  riljOlI-{CHOH),-OXiH, 
and  are  therefore  stereoiaomprs.  <)n  stmnger  oxidation,  both  arabin- 
ose and  xylose  yield  friVM/driwyy^wJ'aru- am/,  CX)0H(CHOH  J, -CXX)!!, 
the  constitution  of  which  follows  from  its  n'<Ii»rti'm  to  glutaric 
acid.  The  acid  obtained  from  arabinnst!  is  optically  active,  and 
tliat  frtini  xylose  is  inactive,  so  that  they,  I^hi,  arr  sterr<it»on)eis. 
On  n-ducUou,  tbeae  two  pentusui  yield   rrt*i>cctivcly  arabUoi  and 


PENTOSES. 


»63 


xjflilol,  which  are  stereoisomeric  pcntahytlric  olcoliois.  Arabinosc 
and  xyloee  can  be  converte<i  into  hextwics  by  the  c>'anhydrin 
Kynthesis,  a  proof  that  neither  coiitaian  a  C-atrmi  in  union  with 
more  tlmu  ooe  OH-group  (209): 

CH,OH(CHOH),-cJJ  -»    CH,0H-(CH0H),'C<9»  -V 


CH,OII.[CII0]a.CilOH-CO0H. 


fhis  hexonic  acid  j-ifUls  a  laftono  which,  on  induction,  pivcs  the 
hcocoBP,  Arabiuiwe  and  xylose  contain  three  asymmetric  C-atoma, 
and  are  optically  active.  Tlieir  aqiipous  solutions,  in  common 
with  those  of  several  other  nptirally  active  substances,  ejchihit  a 
phenomenon  called  initlti-rolait'oti,  fresh  solutions  rotating  the 
plane  of  polarization  much  more  than  those  which  have  stood  for 
gome  time.  For  xylose,  five  minute?  ftftor  it  has  (wf-n  dissolved, 
the  value  of  [a]  is  75°-S0°;  this  pndually  iliminislies  to  19*, 
after  which  it  remains  constant. 

This  phetomonon  is  probably  due  to  tlio  conversion  i>(  the  sub- 
sliLiicQ  iiiio  aii<>i)ii;r  imxllflciiLlon,  nnnlogous  to  lliat  of  lactooos  into 
acltb.     Tlim,  a  tTvuh  aoluiiou  at  xylose  would  coalaio 

OU.OU-Caon-CHOH-OH-CoH 
O 

While  lfttoreU,OU.(Onon)fCnon-c{5  is  formed,    This  viow  Issup- 

poned  br  the  fact  that  tlie  rotaiory  power  of  a  lactone  ib  dimiuished 
by  op«iiiii£  its  riDK;  an  example  of  (his  is  furnibbeil  by  j^nluctouio 
acid,  only  that  in  it  the  chaugc  of  rotatory  power  takea  pUca  more 
quickly  t)ian  amon^  sn^pirft. 

The  probability  of  the  correctness  of  this  ieterpretatioD  is  stien(tta- 
«iiod  by  the  fact  that  the  ohango  of  Totatory  power  has  lliA  obarftct«r 
of  a  uuimolecular  reaction. 

The  pentoses  have  one  property  in  common,  by  which  they  may 
be  recognixed  and  distingiii.>ihed  from  hexoses.  When  txiiled  with 
dilute  sul[jhuric  acid,  or  iiydruchhirio  acid  of  sp.  gr.  1  ■  ()6,  the  pent- 
oses and  their  pulyoaes  funn  a  vtdatile  compound,  fiiTJuraldehyde, 
C^HjO,  C391),  which,  on  ireaUiient  with  aniline  and  hydwcliloric 
acid,  yields  an  intense  red  dye. 


aH  ORGANIC  CHEMISTRY. 

TIm  pMMBM  or  tho  polfoso  of  xylow  mny  be  det«et«d  tn  such  a| 
substuntM;  OB  sftaw,  by  tlistillntioti  with  byiirochlorio  acid  of  »p,  gr,  1  08 
Vitli  BUJli[it.>  atiil  b^vdruciiluric  »oid.  tbe  ilUtillato  givt-R  su  iDteDse  red 
colourfttinr,  and  with  phenyl  hydrazine  yield*  a  phenylhydranone  fvrji 
sparingly  soluble  id  water.    Botli  tb«se  reactions  indicate  tbe  [iresaneti^ 
of  furfunildehj'de. 


Eexosea. 

212.  The  hexosn  are  colourlens  compoucds  of  sn'cet  Xnt^s, 
which  orj'staltizc  with  difficully,  and  cannot  be  diAtillcH  without 
df'cnitiijfxsitinn.  Th(^y  dissulve  n-adilv  in  water,  with  itifficiilty  in 
aiwuhito  alruhi>I,  and  are  insohibk-  in  I'ther.  Sint-e  all  (he  ald<>- 
licxfisrs  an-  slrn-oiaonicrs  (SOS),  tlifir  oxidation-products,  the 
nionnljiistc  (ind  dibask-  aci\\s,  an*  alao  stereoiiKiiiuTS. 

1.  (/Ywcoac,  f>r  Krape-su^ar.  is  prfsi'iii  in  many  plants,  notably  in 
the  juice  of  grapes,  and  in  other  swoct  fruits;  it  ia  found  in  the 
urine  of  diabetir  patipnlii,  and  in  small  cjuantitics  in  normal  urine. 
It  can  lie  ohtained  fmm  many  polycwM^;  cane-siignr  is  converted 
by  liydmlytiis — invir»ion,  C217)~inIo  n  mixture  of  glucose  anj 
fnirtnwr,  oaik-d  iniTii-HugiiT.  ]iy  the  same  trralment,  stArch 
yields  gluoftse,  which  ia  tochnically  prepared  from  it  by  boiling 
with  dilut*  acids. 

(ilucosc  crystallizes  from  water,  op  alcohol,  with  some  difR- 
culty;  the  crystals  obtained  fmm  methyl  alcohol  contain  no  water 
of  crystallization,  and  ntelt  at  1+6°.  It  has  been  already  men- 
tioned (47)  (hat  ^iKicose  ran  be  readily  fprmented,  producing  chiefly 
alcohol  and  carbon  dioxide.  iK  is  dcxtro-rotator>',  and  exhibits 
multi-rotation;  a  ia-vo-rotator^*  and  an  optically  inactive  modifi- 
cation have  been  artificially  prepared.  The  dextro-rotatory,  Ubvo- 
rotstory,  and  optically  inacti%'e  isomers  are  respectively  diatin- 
guished  by  the  prefixes  d  (dexter),  I  {litvus),  and  £  iinaclive);  thus, 
f^-glucoee,  ^glucose,  i-glucoee. 

By  ooiivoulion,  all  oth«r  monoMs  tlorivod  from  a  d-,  1-,  or  {• 
bezoM  are  also  dtstinguiatied  by  the  letlers  d,  L,  or  i,  «vea  wboo 
tbejT  poaaeas  a  rotAtory  power  opposite  in  sifcn  tn  that  iadtoated 
these  letters!.  In  thin  way,  ordinary  fruotose,  which  can  be  obtain 
froDl  (^glucono,  uDil  is  lutvo- roUlory,  ia  oallvd  rf-fruotose  on  Hccoac 
oftls  genoltc  rols.tfoii  to  ti-giaao&e.  The  samo  method  of  cUssie 
lion  ia  adopted  for  the  beialiydric  akohola,  the  hcxoolo  acids,  and  to 
(emrtl  for  all  derlTatives  of  tbe  hexoses. 


HEXOSES. 


if-Gluwtfo  is  an  aldose,  as  is  proved  by  its  oxjflation  to  a  hex- 

Onicacid.  li^fufome  aCTVf,CH,0H-(CH0H3,-COOH;  further oxidi^. 

Uon  proihieps  ihc dibasic  rf-saccharii;  aeid,  C{K)H ■  (CHOHl^-COOH. ' 

Snccbaric  ncid  forms  u  charai'li^ristio  nd<l  pota&sium  aall  at  Hliglit 

aolubiliiy.  which  servta  aa  a  lest  for  tt-eiueoav.    Tlie  subslniicc  »us- 

p«ct«il  to  conlniu  glucoM  is  oxidiiii'^I  with  nunc  Jicid  ;  s««ch.nric  acid 

is  pHHlitci-tt  frum  cliis  licirac,  if  pr<;^iit,  and  can  bo  precipitated  in 

tlie  fonii  of  till.'  uulil  piKiisKiuiii  Mlt  by  ailditioa  of  a  concentrated 

solution  of  poi'iLsiiium  acetate. 

On  reduction,  if-glucosc  j-ields  a  hexahydrie  alco!iol,  d-atirfnlot; 
It  also  gi^'es  an  nsazojie,  {\tjltifosaiom-,  which  is  stduble  with  diDi- 
euttv  in  water,  and  rn.'stallizcs  in  yellow  ncedlet*  which  melt  at 

d-Cilucose  ia  mnployed  as  a  subfttitiitc  for  cane-sugar,  and 
applied  to  nmity  ntlit>r  puriwses,  on  account  of  its  sweet  tasto, 
which  is  however  lewt  prommnced  thsii  Lhat  of  caiie-migar.  With 
a  i^niall  quantity  of  water,  it  yirida  a  coloiirless  syrup,  used  in  the 
preparation  of  liciucurx  and  of  con ftretiom-ry. 

2.  d-t'ru^^tosc  is  prcseul  aluii^  with  </-gluc'>sc  in  njost  s\*'eet 
its.  It  is  a  constitiient  of  invert-sugar  (217),  and  of  honey,  which 
ia  chiefly  a  natuml  invcrt-innger,  tnuUn  is  n  polyosc  contained  in 
dahiia-tubers ,  and  when  hydrolyneif,  yields  only  rf-fmetose,  just,  as 
starch  yields  if-ghicose.  rf-Fnicto.'«e  cn-stallizes  witli  difficulty, 
being  readily  solublr  in  water,  ftlthoiigh  less  so  than  grape-sugar. 
^It  is  Iffivo-rotatwry,  and  can  Iw  fermented, 

d-Fructose  is  a  type  of  the  Icctoses.  few  of  which  are  known. 

[Ita  formula,  CH,OH.(CHOH),  CO-CH,OH,  is  deduciWe  frotn  the 

tfoUowing  con«derations.     First,  when  oxidij^cd  with  mercuric  oxidaj 

iln  presence  of  baryta-water,  it  is   converted  into  glycolUc  aac 

CHjOH-COOH,  and  trihydmxyglutaric  acid,  "  ? 

coon-(cnoH),-cooii. 

^Since  oxidation  takes  place  in  the  cariwnyl-group,  the  production 
Htif  these  acids  necessitates  the  adoption  of    this    constitutional 
Bfonnula.    Second,    applicaiion   of  the  cyanhydrin    synthesis  to  a 
H  eompound  of  this  constitution  would  yield  a  heptonic  acid  with, 
the  formula 

»CH,OH  -  (CH(OH),-  C(OH)  -CH.OH. 
ixiOH 
That  the  heptonic  acid  obtained  from  d-fnicttMe  haa  this  consti- 


Bfruit 


sfiti 


ORGANIC  CHEMISTRY. 


tulion,  ia  proved  by  heating  it  at  ft  high  temperature  n-ith 
hydriodic  acid,  whereby  all  the  hvdroxyl-groups  are  replaced  by 
hydrogen,  and  a  heptylic  acid  is  fonned.  This  is  found  to  be 
identical  with  the  Bv-mh^tieally-prepared  meth}firTi'bul\fiacetic  acid. 
(S3&,  2),  whoso  coixstitutiunal  formula  is 

CH,-(CH,),.CH-CR, 

Tlie  asazone  of  ri-fnicinw  i^  identieal  with  that  of  d-gluoose.   A 
coniparisun  of  the  fnniiula  of  f/-ghicoac, 

CHjOH  ■  (CUOU),  ■  CHOH  ■  Cy , 

with  thatofd-fnittosL>,CH,OH.(CHOH)^-CO-CH,OH,  shows  that 
the  two  wsaaunes  caii  only  be  i<lrnticiij  if  the  fr-0«.l(Hi»  t>f  lh^l'/-K:lu-^ 
cose,  and  the  tcmuiial  C-atom  of  the  rf-fnictose,  unite,  after  for- 
mntinn  of  the  hydrarone,  with  iho second  phcnylbvdrazinc-refudue ; 
that  is,  when  ui  hulh  eases  thin  n>aetii)ii  taki'S  place  at  a  C-alom 
dtn>ctly  linked  to  a  earliiinyl-gnnip.  For  lliis  reason,  il  is  aasumed 
that  the  forntation  of  an  DsaEiintr  always  iraulta  in  the  union  of 
two  phenylhydnudne-residufa  with  iieiglilwurinK  C-atoma.  The 
glufx)sazoiu;,  or  fnictusazonf,  has  the  cuustituliua 

(CHOH), 
C-NNH.C,H, 

H 

It  is  a  somewbat  remarkable  fact  that  methylphenylhydraxtne^ 
C^Hg-  N(CH,)  ■  NHj,  yields  osazones  only  with  ketoses.  and  not  with 
aldnses.  The  Inlter  form  colourlej«  hydraBoiies  willi  this  com- 
pound, and  these  can  easily  be  separated  from  the  iatcnstdy' 
yellow  osazoncs.  Mclhylphenylhydnizine  therefore  affords  •  valu- 
able means  of  deteeliiig  ketostw. 

When  the  osazones  are  earefully  warnieil  willi  liydrooblorio  aojil, 

two  molecules  of  phedvllij-clmziiie  are  split  olT,  wtih  ronnation  of  oom- 

poaadfl,  oKOfief,  eontniniDg  iwo  CKcbooyl-groups.     Id  tbls  way,  gUu>- 

osaEono  yields  gluwutm^ 


CH,OH-lCHOH),.CO-0, 


O* 


a67 


^m    Otlu 

■  CH, 


The  OBonDS  cnn  ba  rocluccd  by  tnwLmVDt  with  zino-doat  and  ncvtic 
acid,  and  eipurieiic«  lias   sbown  that  addition  of  hydrogen  »laayi 
lAkes  |ilAce   ai  tbo  tcrmliikl  ('-«tou).     Oliicoeone  yields  fruvtijot- 
CH,OH.{0HOH),-C0-CH,On.    This  njuciion  afforda  n  mennsof  eon- 
Tortiog  aldoeea  into  ketones: 

Aldotio  —  Ouuone  -*  0«ooo  -•  Kelotw. 

loTcnol}',  nn  nldose  caa  be  oUiuned  from  a  ketooe.  On  reduction, 
the  Inner  yivldsa  bexali^rdric  alcohol,  which  l8  C0DVurl«d  by  oxidiitioii 
into  a  oionobasia  hox»n>c  ucid.  This  subetanoo  aplita  oS  water,  yicld- 
Int;  llie  corresponding  lactonti,  whiob  on  rviluotlon  git'oe  the  aldose : 

Kclnsp  -*  IlQSnbydric  Atcniiol  -*  Hoxonle  Acid  -•  [jictoiic-*  Aldose, 
3.  d-Mantwa^  in  an  aldose,  and  is  present  as  &  puly<«sr  in  tlie 
Tcgct  able-ivory  mit;  it  is  alao  oblainetl  by  the  cart-ful  oxidation  of 
the  hcxahydric  alcohol  mannitol,  touiul  in  uevonil  planta.  d-Mannosc, 
a  hard,  amorphoiiB,  hygro«enpic«ulwtance,  can  ho  n-fldily  fprm^nteii, 
and  is  vt'ty  Kolublo  in  water.  It  fornis  a  rtmroctt'rLstic  hydrnxone 
which  melts  at  lOS'-SflO",  arui,  luililcc:  iIih  hydraaones  of  the 
other  monosos,  (li«sc»lvna  witli  difficuhy  in  water.  On  oxidation, 
rf-monnoBc  i»  first  convcrtrfl  into  tlic  monnbaxit;  tl-jiuumonic  acid. 
Cn,0H-(CIIOH),-C00Ii,  a»d  then  into  the  dibasic  d-manw 
^xhark  acid,  C0OH-(CHOH).000H.  It  yields  (/-glucose  by  a 
;ho<I  gnncrally  applicabk*  Xm  \\w  conversion  of  aldoses  into  their 
stereoitfomers.  For  this  purpose,  ii  is  firet  convorWKl  intorf-mann- 
onic  aeiil;  this  is  heated,  preferably  by  boiling  its  soUiiinn  In 
quinoliniN  winch  eoiiverta  it  parti}'  ijito  the  atercoisonieric  rf-ghio 
onic  anid,  whose  lactone  can  be  reduced  to  (/-sIucom*.  Inverwly, 
4J-gluoonio  acid  is  partly  change^  into  (/-niannonic  acid,  by  Ixiiting 
its  quinoline  solution,  so  that  j-gluetiw;  can  be  converted  iiilo 
cf-mannoso. 

MauuoDic  acid  ia  one  of  tbo  intBrincdiato  prodnols  ia  Bun. 
FiscHKitN  synthesis  of  (/-glucose.  lie  conrerted  gljroeraldehjde  Into 
vxxwe  fSlO,  4),  ami  llii«  inio  i-Bi.innilol,  by  rciluction  wilU  iwdiuni 
atiiiilgittu.  On  oxiditltoii.  ^-manoitol  yit-lds  Dm  i-maniins^,  and 
tboa  t-mauQoniv  ncid,  Aliidi  cnii  be  *f>IiC  U{>,  by  mranaof  its  etrycb- 
nine  s:ill,  into  its  opiiadly  aclive  modtAcnlioDS.  Wliva  tbe  O-voBa- 
nonic  acid-iliiu  •^l>t{iiiiAl  ix  bonled  willi  pyridlno,  il  ia  converted  into 
d-glucouic  add,  ilie  kcii>Q«  of  wblcli,  ou  reduotioii  with  sodium  amal- 
gam, yieldarf-glucodo, 

The  stcreoisoinerism  of  ti-tnannosc  and  (/-gltiorote,  as  well  as  o( 
moanonic  ucid  and  (J-glucuuic  acid,  is  uccaaioned  onlv  by  difTcrent 


968 


ORGANIC  CHEMISTRY, 


grouping  round  the  a-C-atutn,  sinoe  the  nsaxono  of  rf-m&nnose  w 
identical  with  that  oi  (/-^ucose.    Aa  this  has  the  cotistitutioa 

CH,OHCnOUCnOU  CHOH-C— C-NMl  c,n,, 

N  NHCJI, 

tbeae  (wuonca  can  only  be  Ulentical  when  tb«  residue 

CHjOH  ■  (CHOH),  ■  CHOH— 

in  (f-Dianoost!  and  d-glucose  is  also  idi'ntJcal;  their  Rl«reotsoimeriani 
caa  then  outy  result  rroiii  a  diflTerencc  lu  the  airaogpjiipnt  of  the 
groups  linked  to  the  a-C-atom, 

So  for  as  the  tnuisfommtiona  of  the  nioDoba^ir  liexonic  acids 
when  boilod  n-ith  quinolinc  or  p\*ridme.  have  bw^n  studied,  it  luia 
alwa\'8  t>o€n  found  ttist  an  alt'-ration  takc-^  place,  as  in  the  above 
iiunancp,  at  only  one  C-atom,  the  one  adjoining  the  aldehyde- 
group,  the  a-C-atom. 

Very  remarlcablo  ia  the  conversion  into  eacli  i^tior,  dinov-ered  bjr 
LoBsr  DR  Bkutm,  of  glucose,  frndtose,  nnd  nianiio««,  under  the  iuOa- 
i-iicv  of  wry  (lilutu  nikulb.  Tlieir  rutntorj  power  is  coDftMlerably 
reduced  thereby;  Mcb  of  tlioM  hoxoaes  fornu  both  lUe  otfacra,  and  tba 
oDe  oriinRaUy  prcseol  is  not  completvlv  ooQTorced.  An  (xjuilibriun 
is  thus  eotablishod  vrbi«li  mvf  be  reprosenied  t>y  iliesobonio 

Glucose  ~*  FruotoM  *~*  ^twoK. 

Thai  frudoM  b  ncLunlltr  an  tiitAniioc]liit(>  prodiiot  n(  this  transronna* 
tion,  is  stiovrn  by  Ihu  buluiTimir  of  llio  dtxtro-rotatoT)'  eolation  of 
mannoee,  vrhiuli,  owiii);  tu  tlid  rormntiuii  uf  Friiorose,  first  deretopa 
iBvo-rolAtioii,  this  grsd sally  ticoroiuiiig  na  tho  dcxtro-rotalorr  gloooso 
Ir  produced. 

4  mid  IS.  l-fflniooM  and  \-maHn'nit  aro  inijiortaiit  on  acoount  of 
tbeir  molliixl  of  rurm«li»a.  Tlwy  nutull  tiaiiiltaiieously  from  /-am- 
biooM  by  npitlication  of  tlio  cyAnhydriii  synthesis,  and  mdootion  of 
tba  lacioae  of  the  neld  thos  forined.  It  was  nittntioiied  (IH)  wby  the 
application  of  tlii*  syotlivsia  to  aldchyd«*  Mlmnys  Icnda  to  ibe  prodoo- 
tlon  of  two  stereoisotnent ;  an  MymoMtrio  C-atom  results,  and  ooa 
optionllj  actire  iaomor  is  as  likely  to  be  formed  &a  tho  other.  In  tba 
ease  of  ^rabinoie,  there  nre  asymmetric  C^aloma  already  pre^eoi  in 
tb«  molecuitt,  and  an  aidiUoiml  one  'm  prodtwed  by  tbu  syotticaia;  tUo 
ilomeiK  display  disaimilar  rotAlor;  power,  but  this  is  no  longer  «{aal 
and  opposite  in  si^a,  stnco  the  original  rolatioo  is  inemsed  in  oae 


MONOSES. 

Isnmer  by  the  now  iLsymnifltrio  C-ntiiin  to  lltn  lutmn  «sfptit  ns  It  is 
dimioisbed  in  ttie  uOiur.  Th<;  rolntioii  of  Uio  isomers  is  equal  and  of 
opiMclta  sifpi  only  when  Iho  originnl  iiiolw»]e  wns  optically  inaotiva. 

6.  d-Gaiaciose  can  be  obtained  by  the  hy»bt)Iy3is  of  lactose,  or 
by  the  oxidation  of  the  hexahydric  alcoliol  ditIfi(ol,  utiich  ot-cur*  hi 
certain  plants,  tf-^^alactoee  is  cr>'stalliDc,  mcUiiiK  at  1GS°;  it  is 
strongly  dextro-rotatory,  is  capable  of  imdcTBoing  fermentation, 
and  exhibits  multi-rotalion.  Gala(-tn,w  is  proved  to  he  an  alilose 
by  it«  conversion,  on  oxidation,  irit^  the  nionohasic  d'^jaiactonic 
ocw/,C,n„0,.  Further  oxidation  yields  the  sparingly  soluble 
dibasic  mttcu:  (wnVi,(XM)n.C('HOH),-a>(.)n,  which  h  opiirally  In- 
active, and  cannot  be  split  up  into  opticjiUy  active  component;  its 
fonaation  serves  aa  a  test  for  (/-galactose.  In  practice  ibis  is  carried 
out  by  oxidizing  the  hexose  under  exam ina lion  with  nitric  acid. 

Their  couvorsion  into  lofmtlinie  acid  (236),  on  trL>ulint?nt  with 
hydrocliloric  avid,  constitutes  a  general  reaction  for  the  bexos(«. 
Brown,  amnrphous  iiijiss«*,  known  as  "liunius  BulwtanM's."  arc  pro- 
duced at  tiiesuine;  time.  LiL-viilinic  acid  can  be  idciitific-d  by  ineaits 
of  its  silver  salt,  which  diaaolvea  with  difficulty,  and  yields  crystals 
of  oharact  eristic  appearance. 

HeptoBSB,  Ootoses,  and  Noaona. 

21S.  Tlicse  aubatancOs  arc  notriatund  producls,  but  can  be  built  up 
from  the  hexowd  by  tb«  cyanliydriu  synlbesin;  miinnofle,  for  example, 
jteldi  mannolieiatut,  matuuMtc/iMe.  mid  mannonomuie. 


i^/ 


Stereochemiitry  of  the  Moaoses. 

114.  It  wasiitator!  (SOO)  Llial  all  the  aldohcxosea  and  aldopontoaM 
haT«  th«  H-ime  structure,  aa  that  their  isomerisni  iDu<it  be  starMian- 
inerixm.  AUIidukIi  H  would  be  licyond  the  scopo  uf  this  bunk  to 
dvdDOo  tho  CMtf\)|:tirullnii  parrciipon'tm}^  to  tlie;  pGnlwcm  and  licxoiiiis 
nteDtioncd  in  tl,  it  is  dc»iral>l^  to  indiciitu  how  lhi»  id  deturnainud  fur 
Mmpoundi  of  ttiis  kind;  Hint  i«,  for  tboM  wnialnlng  several  aayni- 
tDctric  car1»n  atoms  in  Ibc  molcculo. 

It  was  mciilioned  (191)  tlint  tliu  presence  of  two  dissfniilar  aaym- 
tDOtrii;  C-Hloniit  in  a  muleculr  cnuacs  the  osiatenoe  of  a  greater 
namber  nf  ftU'r«nii(omerA  Ihan  tbat  of  two  aimilar  asymmetrio  C-atoma. 
Il  can  be  readily  tasw  fmin  a  projtictiori- formula  thai  ttia  aaiti«  liolds 
good  for  a  greater  nmuber  of  nityrnmrtHc  (.^.alnnis  in  tlic  mu1<wiile. 
The  pro jwtioii- formulae  for  fwo  aldo;i«iiti>s««. 


S70 


ORGANIC  CHEMISTRY. 


and 


H- 

H- 


««OD«t  bo  made  to  eoicuiido  by  roUtton  in  lb*  pliiii*  of  tbe  p»per 
(191);  th«  nldopcDtows.  ihvntorv,  arc  aot  identical.  Tha  correspond- 
ing tTlhjdrozygluiano  acids 


COOH 


HO- 
HO- 
HO- 


-H 
-H 


and 


H- 
H- 
H- 


(^ 


COOH 
OH 

-\ OH 

OH 


CX)OH 


COOH 


KTO,  hofr«Ter,  idcnticat,  sinoo  (heir  proJKtion-fomulie  e«a  b«  mad« 
to  ooiDCido.  Ill  th(!fto  oompoQiuK  lh«  asymuetric  OaUnat  1  and  8 
kn  simitar,  wbiU  Id  tb«  p«nto«e«  th«y  ara  diMlmitar. 

Aasamiitg  that  tbe  detcnmuaiioo  of  the  coofl^uratioa  of  tri- 
ltydroz]ri;:lutano  acid  is  pouib)«,  and  that  in  a  given  instance  it  leads 
to  the  projevlioii-rorinula  given  abore,  it  foItoKn  tltat  tbe  pentostf 
froin  wbtcb  it  ix  obtaiacd  by  ozid&lion  miut  hare  one  of  the  abovr 
configurations,  anil  that  all  others  are  deluded.  Il  tbiu  ooty  renutimi 
to  distinguish  between  theM  two  configurations. 

lo  order  to  detennioo  the  stcreocbcmica]  stnu-ture  of  a  pentou,  it  is. 
th«refore,  first  necessar/  to  determine  tbat  of  th«  correajMnding  Irihy- 
droty^liiljtrlc  iicid.  Tbe  optical  bebaWour  of  tbeae  acids  aifords  a 
rwidy  mcfUJH  of  ffTncting  this.  XyUutn,  which  is  o[>licallT  actire,  \i 
conrcrtcd  by  oxidittiun  into  au  optically  inaclivo  tnhydroiyglutanc 
aeid  which  melta  at  13S*.  Since  au  optically  inactive  anhstnaoeis  here 
obtained  from  an  optically  active  one.  not  from  .i  raoemio  oumpouml. 
lUa  BKUtt  be  occasioned  by  intramolecular  compensation,  which  most 
And  ezproa^oD  lo  tbe  conlijruration  allotted  to  Ibis  piulicular  iribr- 
droxyglotaric  acid.  Proji<«tfi>n-fonnuliD  of  eon^tonnds  wliteh  ar« 
optically  inactive  on  account  of  intramolcoular  oouiproaaiion  must 
fulfil  this  oondition:  each  and  its  DiirrorimagD  ninat  be  <^apable  of 
being  made  lo  coincide  by  rotation  in  tbe  plane  of  tbe  |»per ;  thai 
is,  they  must  be  identical,  yor,  if  tbis  were  not  tha  case,  two  enan- 
tiontorphiiua  coiilI|i:uratii>ns — tlie  fomuU  aod  Its  mitror-lmage-^would 
b«  pOMlble.  wbllo  for  intntniolocnlar  compensation  oalj  one  oonfl^- 
mtioo  is  possible. 

Tbe  BboTo  reasoning  may  be  applied  lo  the  dctennmation  of  the 
stereochemical  stmotare  of  arabinoee.  Eight  alereowoDMric  fonDuIn> 
arc  [Miitsiliie  for  a  pentose,  but,  by  arranging  these  In  pairs  of  mirror- 
imngm,  and  talcing  ono  of  each  pair,  four  different  typn  are  obtained  : 


STEREOCHEMISTRY  OF  THE  MONOSES. 


871 


H — 

H 


CHjOH 


H — 


— OH 
-OH 
-OH 


H 

H — 
HO 


CHjOH 

— OH 
— OH 

H 


C^ 
^O 


Ah 


H — 
HO 
HO 


CHjOH 


— OH 
H 

H 


H- 


CH-OH 
OH 


HO — 
H — 


o§ 


— H 
— OH 
,H 


u 


in 


^0 

rv 


The  mirror-image  of  I  \i  represented  oa  p.  270. 

ArabinoBfl  in  oooverted  by  oxidation  into  an  optically  aotiTe  tri- 
bydrozyglutario  aoid.  Tbis  excludes  tbe  tribydroxyglatario  acids 
wbich  could  be  obtained  from  types  I  and  IV,  since  each  of  theca 
could  be  made  to  coincide  with  its  mirror-image,  and  thus  would  be 
optically  inactive : 


H- 
H- 

H- 


COOH 


-OH 
-OH 
-OH 


COOH 


identical  with  its 
mirror-image, 


HO- 
HO- 
HO- 


OOOH 

— H 
— H 


COOH 


H- 

rv.  HO- 

H- 


COOH 


-OH 

-H 
-OH 


COOH 


TTO- 
identioal  with  its        u 
mirror-image,        -ac\ 


COOH 


-H 

-OH 

-H 


COOH 


The  fact  that  hg  the  aid  of  tbe  cyauhydrin  synthesis  arabinose  can 
be  converted  into  a  mixture  of  glucose  and  mannoae,  wbich  on  oxida- 
tion yields  the  optically  active  saccharic  and  mannosaccharic  acids, 
enables  a  choice  between  types  II  and  III  to  be  made.    Since  in  the 

■a  ri 

cyanhydrin  synthesis  only  the  group  C"  in  CHOH-Cq  is  altered,  the 

conflgaration  of  the  rest  of  the  C-atoms  remaining  unchanged,  sao- 
charie  acid  and  mannosaccharic  acid  most  have  tbe  stereochemical 
structore 


COOH 


H- 

H- 

HO- 

HO- 


-OH 
-OH 
-H 
-H 


COOH 


COOH 


or 


H- 

H- 

HO- 

H- 


-OH 
-OH 
-H 
-OH 


COOH 


tja 


ORGANIC  CHEMISTRY. 


if  arebinosG  in  repreMOtHl  by  fornmla  II.    Neither  of  rhese  cnn 
QUtde  to  coiiii^idfi  wicb  its  mtrmr-imasQ,  so  thai  formula  II  is  umiB 
to  mprfjiGnl  MTnhlnoM>.     FnrniiilA  IH  u  picluded,  bIhoo  iU  aiuimpda 
wonld  DKC^iinti;  thiti  oiiu  of  the  aoidjt  meDtaoRed  nbore  ahould  tuiTe 
tlis  itOEMobemical  constitution 


COOH 


H— 

HO 

HO— 

H— 


-OH 
-H 
-H    ' 
-OH 


COOU 

vlilota  li  MontkAl  mi'h  its  mirror-iinagQ:  one  of  the  acids  vould  tlien 
be  opliciilljr  io!U!tiTO,  wliicli  ia  not  the  case. 

Ariibiiiosc  liiw,  thereforo,  «  formnta  of  tlie  type  II,  but  il  is  (llD 
uncerinin  nhoihcr  it  ahould  tw  repreitcutod  by  tbo  formula  givflD 
above,  or  by  its  mirroNiuuige. 


XL     DIMES 

215.  Numerous  rfwMM  <or  hiosc»)  are  known,  which  are  almost 
exclu^vcly  derived  from  hoxtisea,  aiid  therefore  have  the  EormuU 

C^H^O.,  =  2C.H„0,  -  H,0. 

No  (Jioses  arp  known  whk-h  can  be  decoinpoBcd  intx>  a  pentose 
and  a  hexosu;  on  hyiirolysis,  some  of  thu  hexodlcuctt  y'w\A  twu  dif- 
ferent rnoiiitscs,  and  some  only  one. 

Thi!  hydmlysis  ran  be  effectwl  not  only  by  ImhIuik  with  clijiitc 
acids,  but  also  by  the  action  of  enzymes  (828).  On  account  of  the 
readiness  with  whinh  decomposition  with  water  takes  place,  it  is 
assumed  that  the  mnncKqcK  from  which  n  dioRi'  t»  formed  are  not 
linked  together  tliroiigh  tlie  carbon  atoms,  hut  through  one  or 
more  oxygen  atoms. 

Up  to  the  present,  succeni  in  the  att^'mpt  to  synthesize  difid^es 
from  monosos  has  been  confined  to  the  case  of  maltose;  Croft  ffti^ 
found  that  maltose  is  produced  by  the  action  of  an  ensv-me  called 
taailatt  {222)  on  a  eoni-ciitrali'd  solution  of  glucow.  A«  this 
eniyme  is  al^  able  to  ^plii  tij;  maltose  into  glucoae,  it  is  eTideut 
that  an  equilibrium  mu^t  be  reached: 


c»u„o„  +  H,0;ir2C,H;A 


firOSE  AND  LACTOSE. 

The  besVknoym  dioses,  siirh  as  sumnie  or  cano-sugar.  and  larlotce 
[,t>r  milk-dugar,  have  aot  ytt  bccii  prepared  syDtbctically. 

Maltose. 

^faUMe  in  the  en-sialJizod  state  has  the  formula  C,jH„0„  +  H,0, 

J«id  cnn  l>p  prrparwi  from  .starch  by  the  action  of  diastAso  (47); 

litis  an  important  intt^rmediate  product  in  the  industriftl  produc- 

•tiun  nf  alrnhnl. 

MalTosf  cryst*llizes  in  small,  white  netdles,  and  is  strongly 

I  drxtri>mt*tor}'.  When  lioiled  with  diliitr  mineral  acids,  it  yields 
only  d-^lucotc.  It  exhibits  all  the  characteristics  of  the  nionoses  ; 
thus,  it  reduces  an  all<aline  copper  solution;  yields  an  osazone. 
moKosaione,  (C„H„0„  -  2H,0  -  2H  +  2C,H,XH  ■  NH,) ;  arid  it  can 
bt  oxidized  to  the  iiiounhHsic  /»ifi/(n'»i'»Ki>  nnVf,  C[,H„0„,  whieh, 
fin  hydrolyaift,  spHtis  up  iiitii  (/-glncnsr'  and  «/-glTicon:c  acid, 
CH,()H-(rHOH).  {.'(>()H. 

These  properties  sJiow  tliat  maltose  contains  only  one  of  the  two 
earhiinyl-groups  present  in  two  ciiolec^uleti  of  (/-|u;lui;uHe  ;  thus,  it 
yieltia  aD  osantme  with  two.  inatt-ad  of  four,  molecules  of  phenyl- 
hydrazine,  and  u  inoiioliaaic  insitad  of  u  dibasic  acid.  The  Unluii; 
of  the  two  muWuh-a  of  (/-kIucosl-  must,  therefore,  take  place  in  such 
■  way  tliat  the  carbouyl-oxVKCu  of  ouiy  one  molecule  enters  into  the 
reaction.  A  union  of  this  kind  between  two  monwe  molcflulej*  is 
called  the  monoraThnntjl-Uond.  If  this  is  denoted  l>y  the  sign  <,  and 
a  free  carbonyl-group  In  a  raoleculR  by  < ,  then  maltocse  can  be  repre- 
eent^dby 

OHi.O,  <oc,n,A  <. 

uluoine  OluiMM 


Lactoie  or  Sfilk-augar. 

816.  iMctose  in  prrM-nt  in  milk,  and  is  prepared  from  it. 

\Mtey  is  iisiiaU>  n(Ui>l>;y«d  for  Itiia  pur[io!ie  ;  it  in  tli«  liquid  which 

romainfl  after  llio  cnjain  hut  bo«n  separnled  and  tha  Hlclmiaed  cntlk 

j^bas  lx!i:n  used  for  waking  cliocso.      In  thono  procensca  Ifaa  milk  ix 

uprivu^t  of  most  of  its  fats  and  nlbutDiiious  substau(»!«;  ttic  wbej 

tntaias  Dearly  all  tho  lactwc,  and  a  large  proportian  of  the  roineral 

'eonMtluents  of  ttie  millc.     The  lactose  Is  obtained  by  evaporation,  and 

purified  hy  rccrjittJilIiLdtioii. 

Ijietosf  crystallizes  in  well-defined,  lanp%  IiarJ  crystals.     It  has 
kot  such  a  ifwevt  ta^tte  as  sueri>.-<e,  and  in  the  mouth  resembles  sand. 


274 


ORGMNIC  CHEMISTKY. 


OD  account  of  the  hardness  of  its  crystals,  so  that  it  is  sometimes^ 
called  mnd-syigax. 

Od  h}'drolysis,  lactoee  splits  up  into  i/^alactosc  and  (^-glucow. 
It  shows  the  reactions  of  the  monoses,  and  can  be  proved,  by  a 
.method  analogous  to  that  einployeii  for  maltose,  to  contain  one 
.  free  carbon yl-group  in  the  moicculie,  so  tlmt  it  is  a  combination  of 
d>^ucose  and  if-gslactoee,  linked  by  a  monooarbonyl-bond.  The 
free  corbiinyl-gToup  iM'toiigK  to  the  rf-gliimse  molecule,  since  lad- 
ose  is  cnnveii-wl  by  oxidation  with  bniinine-watcr  into  lactohionic 
acid,  which  is  split  up  by  hydnil.vsis  into  d-galactose  and  d-gluconic 
acid.     Lactofic  is,  therefore,  rcpresciitcd  by 

C^„0»<0-C,H,A  < 

■UlaUvtOM  li-Uluoow 

SacroM  or  Cane-su^r. 

?17.  Sitcroee  (sacchoroso)  is  present  in  many  plants,  and  is  pre- 
pared from  Kiigar-lK-et  and  sugar-raiie.  It  pryslalliiies  well,  and  is 
verj'  rcwlily  snluble  in  water.  Jt  melts  at  360",  and  »nlidifit>s  on 
cooling  to  an  amorphous,  gIa.-»>liko  ma-ss,  which  aftrr  a  considerable 
time  becomes  cryatalUtie,  ^l^■hc^  Ktrongly  heated  it  turns  brown, 
being  converted  into  a  siibstance  called  caramcL  On  hydmlysis, 
sucrose  yields  rf-glucose  nnd  rf-fniptosc  in  equal  proportions.  This 
inixturois  cAlIcd  inv€rt-t\iQar,&.i\A  is  Ificvo-rotatopy,  since  rf-fr\tctose 
rotates  the  plane  of  polarisation  more  to  the  left  (212)  tlum  cf-glucHse 
does  to  the  right.  Sucrose  itself  is  strongly  dextro-notatorj' .  so  iliat 
the  rotation  has  been  reversed  by  hydrolysia.  This  is  colled  iViitit- 
turn,  a  term  also  applied  to  the  hydrolysis  of  other  diosc^  and  of 
polyoses.  Sucrose  does  not  show  the  reactions  characteristic  of 
the  monnses;  thus,  it.  does  not  mduce  an  alkaline  cop)>er  solution,  is 
not  turned  brown  by  eanstJc  pota.<;h,  and  does  not  yield  an  osaaone. 
Hence,  it  is  evident  that  thrre  are  nn  free  carbonyl-groups  in  its 
molecule;  it  may,  ihercfon-,  be  ctmcludei^l  that  iHtth  of  these  have 
enierctl  into  reaction  in  the  uninn  of  the  two  monosrs.  Such  a 
linking  between  two  muiioscTs  is  called  a  dicarbonyl-hond,  ami  is 
represented  by  the  sign  <0>  ;  so  that  sucrose  is 

C,H„0,  <0>  C,H„0,. 

216.  The  discovery  that  alcohols  are  able,  under  the  influence  of 
hydrochloric  acid,  to  unite  with  raonoses  with  elimination  of  water, 


SUCROSE  OR   C^NESUGAR. 


*7S. 


affords  an  insight  into  the  nature  of  tlie  monocarbonyl-bord  and 
ihf  dicarbonyl-bontl.  Thi-  substances  thus  formed  are  tailed  glueoa- 
iiles,  jdnce  thvy  are  in  iiiaiiy'  ways  analogous  to  the  natural  glucw- 
ides,  siibstariees  which  are  sjJit  wp  into  a  siipar,  and  one  iir  jnore 
compounds  of  various  kitids,on  Iwuling  w-ith  dilute  adds-  The  arti- 
ficial glucosides  arc  obtaintnl  by  the  action  of  one  molecule  of  aa 
alcohol  upon  a  uiouosc : 

C,H„0,  +  CHjOH  =  C,H.,0.-CH,  +  n,0. 

These  compounds  vrem  discovered  by  Kmiu  Firtciiiiit,  who  has 
ossif^d  to  them  a  cotujtitutiun  analogous  lit  some  rcapccls  X<j  that 
oftheacetals  (113,2): 


^^P  HJOCH, 

Aldnliyd*  +     Aloaluil 


AcbUI 


In  tho  formation  of  glucuside,  only  one  molecule  of  alcohol  acts 
upon  the  aldose,  so  that  one  of  the  liydroxyl-groujw  of  Uie  latter 
playn  the  partof  a  WT.ond  alcohol  oiolccule: 


CH,OU 

CHOH 


yCHOlH 
/?CHOHj 
aCHOH 

C!0         +H 

H 


CH,()H 
CHOH 


;9CHOH 
aCHOH 
OCH,     6-OCH, 
H 


The  grounds  for  the  aasiimption  nf  this  constitution  arc:  first, 
these  glucasiiica  an-  readily  split  up  int«  their  components,  wliich 
argues  against  the  cxinti-ncc  of  a  carbon  bond  Iwtween  them ;  second, 
the  hydroxyl  of  the  >'-C-atom  ia  aesumcd  to  Ix;  the  one  which  reacts, 
wnM  other  compounds  containing  the  group  — CHOIICO —  do  not 
yield  glucosides;  the  a- hydroxy  1 -group,  therefore,  does  not  react. 
Tlie  j'-hydroxyl  is,  moreover,  the  most  likely  to  onter  into  rcaetion, 
«ncc  a  number  of  instances  of  similar  behaviour  are  known,  such 
as  that  of  the  lactones. 

The  combination  of  two  monosca  with  elimination  of  one  mole- 
cule of  water  may  be  represented  in  a  way  analogous  to  the  forma- 
tion of  a  glucu^de  froiu  an  alcohol  and  a  uiunose.    Maltose  and 


^^ 


ORGAMC  CHEMrSTKY. 


lactoee,  which  are  united  by  a  monocarbonyl-bond>  and  contain 
WW  free  carbonyl-group,  are  combined  thus: 

CHjOH  CH,OH 


CHOH 


I 


oGHOH 


+H 


(CHOH), 
OCH, 


CHOH 
CHO— 
HaO  +  CHOH 
CHOH 


a 


O 


(CHOH), 


The  constitution  of  cucrose,  in  which  fructose  and  glucoee  ire 
united  by  a  dicarbonyl-bond,  may  be  sho«ni  in  an  analogous  way 
tobo 


CHjOH 
CHOH 

CHO— 
CHOH 
CHOH 

c ■ 


CH,OH 
yCHO— 

/9CH0H 
gCHOH 


^\ 


cir,0H 


Snnmse  forms  fltimpoiinds  with  bafiCA,  called  sacpharates ; 
among  tht-m  arc  C,iHaO„CaO  SHjO,  and  C„HnO„-2CaO,  which 
are  rewlily  soluble  in  wator.  When  this  solutiun  h  boiled,  the 
nearly  bisoKiblc  tricalcium  saccharate  Ci3Ux,Ot,-3CaO>3B,0  is 
precipitated. 

UanufactDre  of  Cane-sugar. 

219.  Sucrose  is  present  in  solution  in  the  cell-fluid  of  the 
sugar-beet  and  sugar-cane.  The  cell-walla  arc  lined  with  a  thin, 
cotitinuoua  layer  of  protoplasm,  eoiiitiitutiiif;  a  8eini-i>enncabJe 
ruembranc  (13),  whicli  pre\cnts  the  diffusion  of  the  sugar  from  the 
cells  at  urdinarj'  leni|)eralures.  When  placed  in  water  at  80*-9CP, 
the  piMtopia^iin  is  killed,  coagulates,  and  drvelops  minute  rup- 
turta,  through  whidi  the  cell-flukl  can  difTuse.  The  prooeea  's 
facilitated  by  cutting  up  the  cane  or  bttt  into  pieces  2  to  3  mm-  in 
thickness.  In  order  to  nialvi'  the  diffiisinn-priipesa  as  complete  as 
possible  with  a  niininium  amount  of  water,  the  slices  are  placed  in 
vats  throiigli  which  water  eireulatep  in  such  a  way  tliat  the  neariy 
exhausted  material  is  acted  on  by  fresh  water,  while  tliat.  which  la 


CANE-SUi 


only  partly  cxhausW'4  ooni<'s  into  contact  with  the  solution  already 
obtained,  so  that  the  material  richoal  in  .sugar  is  treaHnl  with  the 
strongest  extract,  and  vice  ittmi  (prinoi[)le  of  the  eoimter-ciirrent). 
In  this  way.  a  12-15  per  cent.  siigar-Rohition  is  obtainefl,  which  is 
about  the  proportion  of  sugar  contained  in  the  beet  itself. 

Slaked  litne  is  added  to  this  solution,  whereby  a  double  object 
is  attained.  First,  the  free  acida  in  the  sap,  such  as  oxalic  and 
citric  acidjt,  are  precipitatwl,  along  with  tiit'  phospliates;  i\\v  removal 
of  thesi'  is  tiecossary,  aiico  they  would  eaiiso  inversion  on  conoeii- 
trating  the  solution.  Second,  albuminous  and  colouring  matters 
are  precipilaled  from  the  solution.  I'or  both  tliese  purposes,  it 
is  necessary  to  add  ati  exwes  of  lime,  part  of  which  goes  into  solution 
a-s  saccharate,  which  ha.i  to  be  ilecomposed  by  a  current  of  carbon 
diftxiile,  care  lH>ing  taken  Xn  leave  the  liquid  faintly  alkaline.  The 
pmei|iilat*'  is  t^eparaUnl  by  a  fUter-prvsH,  and  the  liltrate  cunceii- 
Iratf-d.  In  imler  lo  obtain  Ihe  luaxiinuni  yield  of  augar.lt  is  n*ce 
»ary  (hat  lliis  nfticent ration  should  lake  pUice  at  a  low  temperature^ 
This  is  attained  by  the  use  of  vacuum -]>tuL^.  in  which  the  sugar- 
wlution  boils  under  diminishwl  pressure.  The  first  product  of  the 
concentration  is  a  thick  syrup,  tnoro  strongly  alkaline  than  the 
original  solution.  Calcium  earbonate  is  precipit«te<l  by  repeated 
treatment  with  eniboii  dioxide  unii  I  ihethiek  syrup  is  almost  neutral 
after  which  it  is  filtered,  and  concentrated  until  crystals  of  .stigar 
bejpn  to  separate.  The  solution  i«  then  allowed  to  cool,  when 
more  crystals  are  obtained,  mixed  with  a  syrupy  liftuid,  whicii  a 
removed  in  a  centrifugal  machine.  This  syrup  is  further  crr's- 
tallized  by  slow  agitation  with  a  stirring-apparatus,  and  the  crystals 
are  again  separated  by  meaut^  of  the  centrifugal  machine.  The 
syrup  tlius  obtalued  (molasses)  is  worked  up  for  the  preijaratton  of 
B  aJcohol. 

H  The  cane-sugar  ♦hus  prepared  is  not  pure;  it  is  brown,  and  cou- 
Hloins  a  ctrtain  amount  of  syrup.  The  crude  product  is  purified  by 
HiliMiolving  it,  demlnurizing  with  animal  charcoal,  and  couooD- 
"trating  in  vacuum-pans. 


I 


Qnantitfttlve  Eitimation  of  Cane-iogar. 

SSO.  Tlie  great  pra<*ii(!Ll  inijMirlance  of  cniie-Bugar  makes  it 
[desirable  to  liave  a  quick  and  accurate  methcKl  of  estimating  it 
Ujuantitativety.    This  is  aliuoat  exclu-sivety  done  by  exa.miiiing  its 


>78 


ORGANIC  CHEMtSTRY. 


aqueous  Bolutlan  with  the  polarimctcr  (87,  2).  Since  Tncrosc  il 
strongly  dexlro-nitalnr}'  {{a\„  =  +  Cft-n"),  a  stnnl!  qu&nlity  pro- 
<hices  Hii  appreciable  amuiint  nf  rutation.  Thin  ih  almost  inde- 
pcn4leiit  nf  iht;  tcnitjcraturc,  and  for  prat'tiral  purpdse*  may  be 
cnnisidfn-d  u»  strictly  pntportiDnu!  to  the  concent  ration.  It  ia 
obvious  that  thitt  jnttbod  wiU  only  yiirld  accurate  resultfi  when 
no  other  optically  active  substances  ore  present  io  the  aolutioa. 
If  such  aiibstaneca  are  present,  either  they  niusi  be  removed, 
or  their  efifeel  taken  into  account.  The  former  method  U  adopieil 
in  the  determination  of  the  amount  of  aigsr  in  beet.  The  sample 
jfl  grated  witli  a  fine  rasp,  to  destroy  the  cell  walls,  and  a  weighed 
quantity  of  the  product  is  made  up  to  a  certain  volume  wilb  cold 
water,  whioh  dbeolves  not  only  the  sucrose,  but  also  optically 
aetivn  alhiiminouH  substftnceR.  The  latter  are  preeipitateiJ  with 
lead  aci'tatf?,  filtiTcd  off,  and  tliu  amount  of  rotatiuii  obser\'e<l. 

When  another  sugar  is  present  in  the  solution  along  witti  the 
sucrose,  it  is  nt'crei."iary  to  proct-rrl  by  the  fcetmil  methnd.  Siip- 
podng  gliiGonc  iti  also  prcM^nt,  the-  rotatory  power  of  tho  Noliition, 
which  will  Xw.  ilcxtro-rotatorj-,  vf-  dctemiinccl.  If  it  be  now  inverted, 
the  solution  will  either  diminish  in  dcxtro- rotation,  or  will  become 
Ia?vo-rotatorj-,  sinee  in\'ert— 'iiiRar  is  Ifrvo-rotfttori.'.  The  rotatory 
power  of  an  invert-sugar  solution  obtainecl  from  a  sucrose  solution 
of  giveu  strength  being  known,  th^se  two  (*bserA'ataons  fumii^h  the 
data  by  which  the  percentage  of  glucose  in  c&ne^ugar  can  be 
easily  calculated. 

Teloaity  of  InTersion  of  Snorou. 

S21.  The  equation  for  uiii  molecular  reactions  (101)  may  be 
applied  to  thp  inversion  of  a  diliit<r  solution  of  sucnisc.  If  the 
original  atnonnt  of  the  latter  pn-jwiit  was  p,  and  after  a  certain 
time  the  quantity  x  ha^  been  inverted,  then  the  velocity  «  tn  the 
fraction  of  time  immediately  following,  can  be  expressed  by  tlic 
equatiou 

dx 


dt 


k(p-x), 


in  whioh  ft  is  a  constant.    The  inversion  can  be  effected  by  meane 

of  different  acids,  upon  the  nature  of  which  the  \'cIocity  of  the  reac- 
tion is  dependent,  so  that  different  values  an?  obtained  for  the  veloc- 
ity constant  k.    When  the  values  of  this  constant,  and  of  the  clec* 


38o 


ORGANIC   CHEMISTRY. 


tion  is  inseparable  from  the  presence  and  propagati»m  of  )-eai;t- 
cellfi.  If  it  were  found  pnsBible  U)  tiring  alKtut  fcrniPiitatian  withoul 
tbeir  presence,  this  throrj"  would  fall  lo  tiir  Kntuiid.  KuuAiut 
BucHNGR  has  recently  effected  i\m.  He  trittirtttiil  frcisb  >'ca:<t  with 
eatid.  whereby  the  ixill-walls  were  destroyed.  The  dough-like  miss 
was  subuiitled  to  great  pressure,  which  expressed  n  liquid  (German, 
PrcKMajt) ;  this  was  si-paraled  by  filtration  from  the  cells  stili  float- 
ing ill  it.  BucHNKR  |iri)veti  in  variuiii*  ways  that  this  *'  press-fluid" 
caiitaitiK  neither  livinn:  cells  tior  liviijy  proluplasiii :  for  iiiitiattee,  ihe 
yeast  niay  "be  first  killed  by  bringiiiK  it  into  a  mixture  oC  alcobi^ 
and  ether;  the  pre^^is-fluid  fmiii  this  euii  nevertheless  set  up 
active  fL-niiciitutioii  in  a  solution  of  sugar  quite  as  well  as  wbui  it 
was  obtained  from  li^-inp  yeast.  The  fermentation  is  oaused  by  a 
dissolved  Riihstanee,  which,  nn  atToiint  nl  it.'<  pmpertiefi,  such  ^^^H 
coagulatifm  on  warming,  must  1h>  rlu!«j>f>d  with  nlhununous  bodi^^l 
it  iit  a  kind  of  <^zyine,  In  which  Hucmnkk  has  given  the  name 
zymfiifc.    The yciiatM-elb  only  ha^i'  the  furit^tinn  of  produring  tymaat. 

The  rheiiiical  structure  of  the  fuzynurs  is  Btill  wholly  unknuMiL 
Meet  of  thcru  have  not  been  obtained  in  the  pure  state.  Thar 
power  of  splitting  up  and  deenmposiiig  eompoundi^  is  atno  not  under- 
stood. Hitherto,  only  !vnmll  insight  ha.s  ix'en  obtained  iiitu  the  nn- 
diliona  upon  which  their  action  depends. 

First,  the  ensynies  only  act  at  the  ordinary,  or  at  a  Rlixhtlr 
elevated,  teinperatiire;  Mow  the  freezing-point  their  arti\-it>-  is 
suspended,  but  returns  at  the  ordinary-  temperature;  on  bc«tti^ 
they  are  deconipoaed.  Second,  they  are  sometini<>s  rendered  inac- 
tive (■■  poisoned  ")  by  the  presence  of  stiiall  ipmntities  of  cenam 
substances,  such  as  hydrocyanic  acid.  Ttitrtl,  it  is  ven-  icmaifc- 
able  that  a  given  enzyme  can  only  produce  changes  in  a  few  m^ 
Btannca*  and  has  no  artioit  on  oilier  similar  compounds.  That,  cl 
the  Afferent  monosce  containing  two  tu  nine  C-atoms,  oohr  the 
trioses.  hexwws.  ami  nonoses  undergo  the  alcoholic  fermentatiiK: 
in  fact,  these  are  the  only  onea  which,  according  to  their  ft 
can  be  readily  converted  into  CO,  and  C^ti^OH ;  far  instanoe 
C,1!,0,  -  C.HjOlI  +  COr 

Only  the  monoscs  are  capable  of  being  fermentea  af 
dio^-9  mu8t  firo't  be  converted  into  monosce.     Yeast  cxmi 
enzyme,  inveftase,  which  first  splits  up  sucrose  into  fmcioer 


FERMBNTMTlOyi  AND  THE  ACTION  OF  ENZYMES. 


38l 


ghieoee^    This  ts  proved  by  the  fnct  that  certain  varieties  of  ycaat, 

L which  do  not  rnntaln  invertase,  are  intrapabtc  of  fenncntiiig 
Bucrose;  thus,  Bkykhisck  discovered  Schizoioceharoimfcea  octoa- 
pana,  which  can  ferment  mftltose,  but  not  sucrose.  This  variety 
of  yeast  contains  no  iiivfrta.«*,  but  nialtase,  which  is  the  ensyaie 
^  by  which  maltose  is  hydmlyzed. 

The  property  of  being  split  up  by  enzymes,  posseesed  by  the 
has  been  proved  by  Emil  Fis<?her  lo  Ijo  intimately  i-un- 
ith  their  stereoclioinical  L-diifiguratiuii.  The  three  naturally 
occurring  sugars,  cf-glucose.  rf-nianiiose,  and  d-tructme,  are  capable  of 
undergoing  fennciitEitioii,  and  there  is  a  ^r^'i^t  eiiiiiluiity  in  their 
configurations,  since  they  differ  only  in  the  grouping  round  two 

Il-alonie: 


H — 
,H0- 


O 

— OH 
H 
OH 


H — 


C^ 

^ 


HO — 
HO- 


— OH 


H — 
H — 


CHjOH 

AJUueam 


— H 
— H 

— OH 
— OH 


HO- 


H — 
H — 


CH,OH 
CO 


— H 
— OH 
— OH 


H — 

HO — 

HO — 

H — 


,H 

O 


— OH 

— H 
— H 
— OH 


CHjOH 


CH,OH 
d-VnwUMM 


CH3OH 


^irari 
po 

I  1.^ 


rf-Galactose,  which  is  also  a  natural  product,  hue  a  somewhat  dif- 
'«rent  configuration,  and  is  either  more  slowly  fermented  by  certain 

'icties  of  yeasi,  or  not  at  all.  Tlie  mirror-iinages  of  these  eoin- 
pounrls,  /-gUiCfise.  etc.,  an-  not  capable  of  undergoing  fermentation. 

The  cause  of  these  phcmirnena  is  probably  the  asyiiuiietrir  strue- 
re  of  the  etizyrnc  molecule.  Although  Unwr  si  1  list  an  res  have  not 
"been  obtained  in  the  pure  state,  their  great  resemblance  to  the  ulbu- 
mins,  and  the  probability  of  their  fonnation  from  them,  tvndcr 
their  optical  activity  undoubted ;  that  i.^,  they  are  to  be-  looked  upon 
as  built  up  of  aiymmetrieninleculr^K.  'Hiis  has  led  to  the  hypothesis 
that  there  must  be  a  resemblance  in  molecular  nonfiguratinn  lietween 
the  enzymes  and  the  siibataiiees  which  they  dccompre*ei  and  that 
when  this  reeemliianee  is  wanting,  no  reaction  can  take  plaer.  Kmil 
iecSKR  appropriately  compares  this  resemblance  in  glruciurc  to 

,t  neceasarj'  between  a  lock  and  a  key,  La  order  that  the  latter 
may  pass  the  luek. 

The  application  of  the»e  views  to  the  chemical  processes  which 
go  oa  in  the  mure  lughly  developed  organisms,  leada  to  the  coocep- 


■tha 


9tl3 


ORC/tMC  CHEMISTRY. 


lion  that  generally  in  reactions  ui  which  proteVd  bodies  act.  as  is  un- 
doiibl^'JIy  the  case  in  the  pruluplasm,  the  ronligiiratioii  of  tlie 
molecule  has  the  same  importance  as  its  structure.  Varioiw  plie- 
Domeiia  tnay  be  thus  explained :  Ihc  sweet  ta.st«  pd^acssed  by  one  of 
the  optically  active  asiiaragines,  and  the  absence  of  taste  in  the 
other;  the  different  amount  to  which  the  three  stcreoieonicric 
tartaric  acids  are  oxidixed  in  the  body  of  a  dog  fed  with  them ;  the 
fai't  tliat,  («i  snbcutaneoiiK  injecti<in  of  a  rabbit  with  /-  or  </-ftrabi- 
ntwe,  of  tli(>  fiDit  only  7  [xr  ci!nt.,  <if  the  latter  36  per  cent.,  is 
excretcxl  from  the  body  unchanged  in  the  urine;  and  so  on. 

223.  Investigation  of  the  stereoiffoineri^in  of  the  mcmoees  has 
contributed  t<jwanl«  explaining  why  optically  activ'e  bodies  are 
formed  in  plants,  whliet  Ifiborator)-  sj-nthesea  usually  produce  the 
raconiic  forms.  It  h&s  been  shown  that  tim  h  not  tJie  case  in 
arcifioial  syntheses  elTeetod  with  compounds  already  having  an 
asymmetric  structure.  Mannuse,  for  example,  yields  maimuhept- 
onic  acid  by  the  cyanhydrin  synthesis,  and  it  would  be  expected, 
from  analogy  with  other  cjanhj'drin  syntheses,  that  equal  quanti- 
ties of  two  etercoiHomeric  mnnitoheptonic  acids  would  be  formed. 
This  is,  however,  not  so;  onlj'  one  acid  is  obtained.  This  shows 
that  the  builduig  up  of  a  molooulH  fnim  one  which  is  as\'mn](>irio 
can  continue  in  an  asymmetric  sense.  Sup[K>se  that  mannose  is 
converted  into  mannononosF  by  three  n'|Maitiuns  of  the  cyanhydrin 
fiynt hi'.si.s,  this  always  going  on  in  only  one  diri-ction.  This  nomwe 
might  be  cu])ablc  of  bcinK  split  up  into  the  original  hcxosc  and  a  pro- 
duct coDtaining  three  carbon  atoms;  the  latter  should  then  be 
oplieally  aeti\'e,  and  on^  optieathj  active  molecule  vxnUd  haiv  oc- 
casioned the  formation  of  aiwOitr. 

The  formation  of  sugar  in  the  plant  has  liecn  proved  hy  vege- 
table physiologists  to  take  place  in  the  rhlorophyil-grains,  which  arc 
composed  of  optically  active  stibstances.  It  may  be  asaumcd  that 
the  production  of  sugar  results  from  a  combinatioa  of  carbon  dioxide 
.  or  formaldehyde  with  these  substances,  whoso  asymmetry  has  the 
eifeet  of  making  the  sugar  formed  by  eoodensation  aUo  as}-minetri«. 
As  the  other  sulwtanoes  which  occur  in  plants  are  probably  fonned 
from  sugar,  their  optical  activity  is  easily  understood,  «nce  they  are 
formed  from  optically  active  material. 

This  by  no  nieons  solves  the  problems  of  how  the  first 
optically  acUvc  compound  arose,  and  of  why  nature  has  not  pro- 


STARCH. 


»8s 


TiQ.  flB.— RicR-ATARCH,     X  8*J. 


Flo.  M.— POTATO-BTAHCIl.       X  MO. 


>84 


ORG/INtC  CHEMISTRY. 


which  is  the  fonnula  dtxiucod  from  tbc  results  of  analysis.  Oa 
hydrolysis,  nearly  all  t)ic[)olyo5es  yield  monoscenitb  the  same  num- 
ber c)f  C-atonis,  but  a  pfilyose  which  can  be  split  up  iiiU)  pentose 
and  hex«K<-o  seems  to  be  present  in  the  guim  of  plants. 

Starch. 

926.  Starch  is  the  firat  observable  aasimihition-product  o(  plant 
It  opfurs  ill  largt?  (]iiaiititii!S  in  the  tubers,  roots,  and  seeds  of 
many  plants,  in  wliicli  it  is  present  tn  the  fomi  of  granules  differing 
in  fomi  and  size  in  different  plants.  Tht-se  arc  represented  in  Figs- 
67,  6S,  Bud  69. 


Fio.  ST.—UvK-nTAKtii.     X  SSO. 

Starch  is  insoluble  in  cold  water:  in  hot  Vi-aterit  swells  up  with- 
out dissolving.  It  yields  an  intense  blue  colouration  with  &  dilute 
solution  of  iixiinc,  for  whirh  this  reaction  ser\'e8  as  a  lest.  'WTien 
boiled  with  dilute  aeids,  starch  is  wholly  split  up,  >-iekiing  only 
J-glucose,  When  Btarch-paRte  is  treated  with  diafilare,  it  first 
dis8olve»,  then  the  molecule  splttji  up,  with  ultiniatc  formation  of 
maltose  and  isomallose,  C,iH„0„.  Both  these  methods  of  treats 
ment  yield  intenmrtiiatt:  jiroducts,  however;  these  arc  gum-like  sub- 
atAUCttt,  polyotsca  cuntaluiug  a  smaller  number  of  atoms  in  the  mole- 


286 


OHG^SfC  CHf-MISTRY. 


cule  than  stArch,  callrd  dcxirins.  Dextrin  is  also  obtained  by 
heating  starch  alone,  or  1o  1 10"  with  a  email  quantity  trf  nitric  aciii. 
Starch  docs  net  show  any  of  the  reactions  of  the  monoees;  it 
does  not  reduce  an  alkaline  copper  solution,  nor  resinify  with  alka- 
lis, and  yields  no  compound  with  phenylhydrazino.  This  pmvrs 
the  absence  of  a  free  carlioiiyl-gmup,  so  that  i\s  molecule  must  he 
represented  by 

C,H,„0^<0 C,H„0,<0>C^,oO. 0>C,H^O,. 

It  might  be  EUfi^Bted  that  the  nioleonle  of  etareh  funtains  more 
thaa  nn«  dlcarboiijI-tjoiKi,  when  tlie  fornmlik  would  be,  for  example. 

U.H.,0.<0 C.H,,0,<(.»L\H,.O,.O>t".H«0, 0&C.H,,0.< 

<0>C,Q„04.0>C.H,.0,.0>CiII,,0,  . .  .  0>C*H„O,. 

It  does  not,  since  b^'drolyais  or  a  cAmpoiind  of  Uiis  tjpo  mtut 
j'teld,  in  addition  lo  (/-^lucoeo,  it  subsiniiCL*  ^XMIkO.  ~,  coatainiug 
two  froo  carbonji-groups,  nnd  no  such  prodiicl  liiu  bc«n  obtaiaed  by 
the  bydrolysifl  of  ainrcli. 

Dextrin  can  unite  with  phenyl hydmsin*.  and  exhibit*  tho  re*** 
tlons  or  till)  initnoKes.Ruch  m  rvduction  nf  an  alknliiK'  copper  «o1u1iOB,j 
and  tito  fornintion  of  a  yvllow  colouration  with  allctitit.     U  tniul,! 
therefore,  bo  nsaumod  tu  contain  a  (rue  carbonyl-groupi 

manufacture  of  Starch. 

iXt.  Tbi-  prrwtM  by  wtiidi  starch  is  niannfncturoi]  is  tboorctically 
T«ry  siniple.  When  propni'od  from  potatoes,  the  latter  are  fiu«lj 
ground,  so  an  to  doatroy  the  cell-tissue  mid  lay  bare  itiestarch^graaulcx. 
Tbo  latter  are  then  treated  with  water  in  a  specially  conslrarii-d 
apparatus,  soniewlmt  rearnililiitK  Hftiove,  by  niuNiia  of  which  ibry  are 
washed  out  of  tlio  ccli-tiMii»,  nnd  fictile  on  standing,  after  wbicb  thcf 
art  carefully  wasbied,  and  dricil  elowly. 

Starch  is  rtupIoyo<)  for  many  purposes  in  the  arts ;  as  an  adhesive 
pHAte,  and  for  stifri^niD;;  linen  in  luundri«s.  In  llm  latt«r  proceits,  the 
ttareb-pasti-  i*oonv«rted  by  tho  hrat  of  tliosmoMhin^iron  into  a  stiff, 
sliiniug  l»yi.>r  of  dcictriii,  f^onling  tite  fibres  of  the  liuun.  Starch  is  ol 
great  iuip»rlnuc«  ih  n  large  oonatiluont  of  foods.  It  is  tooru  fully 
treated  of  in  tbia  coouectioii  in  pUysiulogical  text-books. 


Olyoogen,  (C,H„0,),. 

tM.  8t}fcogen  is  a  «Qb«tanci!  lufuiuibliug  starch,  and  is  present  in 
the  animal  organtsm,  the  other  poljoses  Iwituc  vegrtable  products.  It 
b  usually  prepared  from  Uxor,  aud  ia  »  white,  atnorpboas  powder. 


ceuuiosE. 


»87 


dinotving  in  water  tnth  foruAliou  of  an  opnlwocol  aoIuUun.  Oa 
bjrdralyBis,  it  jridds  ooiy  (^glucose.  Ai>parenll¥  Ibere  are  tiittemat 
liiadB  of  glyoo^D,  varying  with  tlio  ftQimnI  (roni  wbich  it  ia  Uolated. 

CelliiloM.  (C,n„0,),. 

229.  Cellulose  is  a  polyosc  of  very  high  molecular  weight.  The 
oell-walls  of  plants  consist  princi|)ally  of  this  )!ubstiin{^'o,  together 
■with  liipim,  which  is  probably  not  a  polyo«?,  Ccllukific  is  very 
stable  towards  dilul*'  a*itls  atid  alkalis.  TliiM  property  in  tiiadt-  use 
of  in  the  technical  preparation  of  cellulose,  in  onlt-r  to  fn-e  it  fn>m 
the  substances  present  along  witli  it  in  the  plftiit-niah-rial. 
iinrti,  cotton,  and  paper  consist  almost  exclusively  of  celluloec;  pure 
filter-paper  is  neiirly  rhemieslly  pure  cellulose.  When  it  is  dis- 
solved ill  strong  Kidphurio  iicid,  and  the  solution  boiled,  after  dilu- 
tion with  water,  it  is  completely  hydrolyzed.  Cellulose  from  eollon- 
w(H>l,  paper,  etc.,  yields  exchisively  fi-glucosc;  from  cofTee-beans, 
cocoa-nibs,  etc.,  rf-maiinosc.  Cellulnsp  is  converted  by  treatment 
nnth  fulphuric  acid  containing  half  in  volume  of  water  into  a  col- 
toidat  modification,  amylo'd,  which  gives  a  blue  colouration  with 
iodine;  thia  reaction  funiiglies  a  te^t  for  cellulose.  Tlio  latter  is 
soluble  in  an  auunoniacal  solution  of  eoppor  oxide  (Scuwritzeh's 
reagent);  from  this  soluiion  it  is  precipitated  cheinieally  un- 
changed by  acids  and  salta,  and  forius  an  amorphous  powder  when 
diied. 

Tecluucal  Applicatioos  of  Cellulose. 

SSO.  Linen  in  olituiiint  from  llit!  stiilk  of  Mik  ItiLX-pItitit.  The  1iu«ll 
flbros  can  be  obtained  from  tiio  tUi  in  scvtral  ways,  since  csIIqIosc  ta 
rery  tiablB  townnLi  cbetnicnl  rmi^^eiits  ;  thiE  enu  b«  cfTected  by  immar- 
sion  of  lliu  Hit!  hi  natter  for  iv  period  of  ten  days  lo  a  furLiiijtiiL,  which 
muiutt  Difl  deciiy  of  the  oxtfirniLl  fibre,  giving  rise  to  a  vory  anplRa&aiit 
smell.  The  process  iskiinwii  oh  "Bleeping."  The  iliis  isftpruid  out  to 
dry,  Hnd  is  ttivn  pasKoit  lliroiigti  corrugHtod  "rullcira"  tu  looM'ii  the 
externnl  woody  flhro ;  Lho  latter  is  slripited  off  by  revolving  wooden 
arms  called  "  wipers,"  this  Ijeing  called  "scutching."  Tliu  lin«n  flbre* 
cno  also  be  obtiviuf  il  from  the  llnz  by  the  fiotfon  at  a  very  diluto  sqIu' 
tlOB  of  alkali ;  tlioy  hitve  a  gray  colour,  nnd  are  bleached  by  eillicr 
being  sproad  out  in  the  opoa,  or  by  menus  of  blracbinK-pu*>'dor. 

^per  was  formerly  prepared  almost  excluttively  fntiu  llnan  rags, 
but  is  DOW  largttly  niauafaotune.!  from  wood  and  straw,  which  mtui 
bedividnl  Inin  fibre*,  anil  lhe<ie  &i>paraud  as  much  im  possible  from 
tbootber,  ao-cniluti  iuunuiiiig,  ftubtttODces  preoeut.    Tbi»  U  etfeoted  bj 


J 


sSS 


ORGANIC  CHEMISTRY. 


the  sulphite  metliod,  in  whicli  the  uoud  ia  bcuted  under  piewure  wilb 
asolQtloa  c(  ftcidsulphltv  of  cnlciuin.  When  Bimw  is  naecl,  it  is  be«t«id 
with  caustic  sotLi  utuler  preuure.  By  Ihis  process  most  of  llial 
iacTuiitini;  ttubsl aiices  aiv  di&aolvfd,  (Lt  tToo<J  or  slmvr  being  bleacheil 
at  tbesaiiiu  uiiie;  Itin  ci^llulot^  wtiich  rr-tiutkiiH  can  tw  roadily  Bepkntt«d 
into  flno  fibres,  which  id  uccosmio'  lo  'lie  maiiufBCturo  of  |»per*pulji. 
It  b  not.  boweTer,  pmuible  to  remove  »U  Ihe  lignin  by  lliis  praoesa, 
wilbtbv  reHult  that  wood-paper  and  atrnw-papcr  aunvrcr  to  the  teats 
for  ti^oiii,  and  can  be  e»ftily  rf-cn^^ixed  by  means  of  Owee.  Ug^nin 
gitOB  a  yellow  colouration  with  suits  of  nnJline.  and  a  red  colouration 
nitb  a  solution  of  pbloruehicinol  iu  ouiiceiitrated  hydrochlorJo  acid. 

PurtJtineitt'paper  i»  prepared  byconrorting  the  outer  surface  of 
paper  Into  amyloid  (ZW),  a  process  wbivli  imparts  toughness  U>  tlw 
paper. 

HltYfttM  of  CcUnloM. 

SSI.  Tliew  compouDdii  are  uf  great  tt^chnical  importance.  Wb«D 
ootlon-wool  is  tr«ated  with  a  mixture  of  nitric  and  sulphuric  acids, 
dlnitrates  to  bexan  it  rates  are  obtained.  Ibis  boing  dependent  u|)oii 
the  concentmtion  of  the  acids,  and  tb*  daration  of  the  i>roccss.  C«l- 
ItUoae  is  ai^ilrarily  Resumed  tu  bavu  the  formula  CuBsiO,,,  aotbnt 
to  Uiedinitrate  is  aseigned  Iho  fortniila  C.iII,.0.(OSOi)„  and  to  the 
beiaiiitrate  CnHnOjONO,)*-  The  solution  in  a  mixluru  of  akirtUol 
and  eUier  of  ilie  dinltrate,  Irinilrate.  and  tetranitrate  \i  Viiown  iis 
colltxtion,  wbiuh  on  cvaporatiuii  li^aroa  an  elaatic  skin,  nnd  is  vm- 
ploTod  in  photography.  The  hvxanitrntf  inffuncotton,  wbich  looks  liVe 
cotton-wool,  but  feels  somowhal  rough  to  Ihc  touch,  and  is  esleosirelr 
tinployed  as  an  «splosive.  It  boms  quietly  wbem  a  looee  tuft  of  it  is 
Ignited,  hut  can  ba  mitde  to  explode  by  the  detonation  of  a  trniall 
amcnnt  of  mercury  fulminate,  and  yields  only  gaaeotis  producif, 
nitrogen,  bydrogun,  watcr-vnpon r,  akrbon  monoxide,  aad  carbon  diox- 
ide. It  «xerts  a  brimnt  action  (180).  and  without  modification  », 
th«r(«fore,  unaiiitabio  for  use  in  nrliltcry. 

When  guncotton  is  diMolre<i  in  awtone  or  ethyl  acetate,  a  geUtitt- 
ous  mass  Is  obtained  ;  after  n'^nioval  of  the  solvent,  an  amorphoua, 
transparent  substance  is  left,  hnving  the  same  diemicnl  vomposittoti 
im  gtinoottnn,  but  biirnini;  and  eiploiling  more  sloivly.  By  ibia  means 
the  Telocity  of  expl'jsiun  can  tio  so  regulated  as  to  malte  gnui'oiton 
available  for  use  in  artillery,  and  it  b  employed  in  this  form  under 
the  name  ■  ■  aniokeless  powder." 

The  licxuiiitratu  ot  cellulose  is  also  nsed  ia  the  manufactiiro  of 
artificial  nilk.  In  DS  CffARnowr.T's  method,  tlie  nitrate  is  dissiilved 
iu  a  iniilnre  of  alcohol  and  cthur,  and  the  nolution  pressed  through 
fino  glass  tubes  under  a  prossare  of  funy  ti>  fifty  aimo«|)h«ros.  Tba 
fllamvnta  are  received  in  water,  which  takes  up  tho  solreot,  toanoc 


AMWODEifiyMTrt^^S  OF  ALDEHYDES  AND  KBTONES.      a89 

Tcry  fine  thread ;  when  t«a  to  twenljr  of  llie«e  are  spun  togL-thvr.  « 
tbread  mpable  of  being  wotod  ia  oUftincd.  WhiMi  llie  fabrio  tlius 
preiwred  i«  treattxl  with  h  solution  of  calcium  iiulpliidtt,  obuinnd  from 
tlip  innk-wiutc  in  tbo  mauiifiic-tura  wf  Budium  carbonate  by  Ihe 
Le  Dla.nc  procewiC'  Iaorita.nlcOlieiiii»lry,"  826;,  the  NOrgro'ips  «t  llie 
citrato  are  «ltmiiint«d,  witb  prwluution  of  DCurly  pure  collulo9»  in  ft 
form  exactly  reaeiubliEigsilk. 

AMINO  DEBtTATITES  OF    ALDEHTDIB  ARD  KEtOlTlfl. 
SS2.  Vt!ry  ffiv  rxnmplea   ot  tliis  class  of  compountls  are  known. 

AmitmiwtaJd«/i^<t^,  t"H,Nn,.c",  axery  uusUiUa  eampottnd,  MB  be 

obtained  from  omituxuMal,    CH.NH,.0,^w,  „  ,  ,  whleh  oan  be  pre- 

pcired  tivm  oioiiochloraacetal,  CBiCl'CUlO0iU*>i.  Htuoarim  a  pg»- 
aibl;  the  oorroipOLdiug  trimettiylamiiioDium  bue  : 

CH,iNCH,),OH 
ig  +  H.O 

It  is  a  orpita111n«,  excMSlretjr  poiaonoos  substance,  and  ia  preMOt  Id 
certikin  pUut«— for  oxtiiuple,  Load-stvul  {A<furia*s  muscariw). 

CliitUu  is  OUR  of  ihe  |>riiicl[>al  coiuttliur'diaof  the  shells  of  the  Crus- 
tacea, suoli  lis  tlig  crub  JiudJobslur;  whuu  hvuled  with  hydrochloric 
add,  it  yivlda  cfiitoMtnine  fi^droc/iioridv,  from  wliicb  the  free  biue 
diUotamirte,  CiHitNOi,  cau  Ui  ubtained  by  tho  action  of  Rodium 
methoxidc  dissolved  inineiliyliikoho].  Chitoaamino undergoes achaiigie 
wh<iti  ita  solution  in  wethyl  idcobol  is  boiled,  since,  on  cooling,  there 
graduiilly  neimralbs  from  ilie  lit|uid  a  crf.il>alline  aubslancc,  identical 
with  /ructttMinine,  whioh  i^  slowly  doveloped  io  a  solatioD  of  fructose 
In  metbj'I  alcohol  contatuiug  auimouia. 


MM.COaH-4^ 


ariisckBiat  ■iHtiii  of  the mnm of  aldefavtlie 
Ktdi.  It  m  yiiMMt  ia  wanpt  tnmla^  and  caa  be  pnptnd  hy  hrat- 
faie<BhroTHnae«dcaod.CHft;,-OOOH.arilh»ater.  Itabonsaluu 
tbe  oxidaitaaa  a<  aleekd  vitfa  Bitrie  arkl,  by  the  mrthod  deaaUied 
nadergbrnzal  (•>■). 

Ad  aeai  from  the  lofante  pm^  abore.  0yoxvSe  mad  ccnuins 
one  ronkcole  of  water,  whkk  aaaot  be  wrpvtted  from  t)M>  acid  ur 
Ita  Baha  vitbout  thrir  utfaiyMiig  dMompotihjacL  For  tUs  msun, 
Um  wai«r  b  ofi«a  aswmed  to  be  in  dmrucal  combinatiao  (158), 
CH(OU),COOH.  ash  H  ta  dikral  h.nlrat«  (MM).    In  both 

mbatancea  the  aldchTde-^^roup,  — Cq,  b  umler  the  influence  tif  i 

atrongly  negative  grdup.  — OC!,  in  chlonJ.  aot]  — CXX)H  in  fdyox 
Uc  acid.  The  latter,  moreover,  posseaaes  all  Uh-  prupertie»  rharac- 
teristic  of  aJdehycIra ;  it  reduces  an  ammoaiacal  silver  Mlulioii,  fomti 
an  additinn-prnditrt  with  sodium  hydrogen  sulphite,  fields  anorime, 
etc.  When  bailed  nith  eaustie  potash,  it  is  converted  into  ; 
and  oxalic  acids,  thc^  fonnation  of  which  may  be  explained  by  ih 
nasumjitinn  ihal  one  molircuU-  tif  tb6  umd  takrs  tip  the  twn  hydni^ 
atotnu,  tuid  another  the  oxygen  atom,  from  one  molecule  of  wntcr; 
H*-  H 


COOH.C     +      O    +    H 

0  ^  u  \      .  o 


:coooH 


-  OOOH-CHjOH  +  COOH-COOH. 

Pyrorftoemic  Acid,  CH.-CO-COOH. 

SS4.  Pifroracrmif  arid,  the  first  meuilx-r  of  the  eeries  at  ke 
acids,  owTs  its  name  to  its  formation  by  the  distillation  of  ettl*f^ 
tartaric  or  racemic  acid  nith  potassium  hydrogen  sulphate. 
Is  {irobahlfi  that  carlvon  dioxide  in  Bnit  flplit  off  from  tartaric  vnl> 

jBGOtHCHOH  CHOH  OOOH.  with   formation  of  glyceric  at^i. 

190 


PYRORACEMIC  ACID. 


49* 


fCH,;o|n  ■  C|H|OfH|  ■  COOrr,  which  gives  pyroracenuo  acid  by  \asa 
of  odc  molecule  of  water;  for  glyceric  acid  itself  is  converted  into 
pyroracemic  apid  by  healing  with  pcitaKsium  hydrogen  Bulphale. 
PjToraceinie  acid  can  Im  obtaintii  synlhc^tically  by  IiydrtJysJs  of  the 
nitrile  formed  by  the  action  of  potaKsium  cyanide  on  acetyl  chloride: 

L  CH,.COa  — CH,-CO.CN-»CH,-C0.CO^. 

TlnaiaageMral method,  for  the  prfparalion  of  a-h:lonic  adds. 

When  heated  to  150°  with  vHlute  sulphuric  aeid,  pyroracemic  acid 
Splits  up  into  carbon  dioxide  and  acctaldchyile : 


CH,.CO-|CO,!H  -  CH,-CjJ  +  CO,. 


f  Pyroracemic  atid  is  liquid  at  ordinary^  but  solid  at  low,  temper- 
atures; it  iiiL'Its  at  9",  boils  at  165°,  and  is  ini^cible  with  water  in 
all  pniportioiis;  its  specific  gravity  is  \-'Zl  at  20",  and  it  hafi  an 
odour  rc-sciiibliiig  that  of  acetic  acid.  It  ifi  a  strunjrer  arid  than 
propionic  acid,  for  which  A'  is  0-(K)I:M;  for  pyromcemic  acid  K  is 
0-56,  which  must  be  fixplaineil  by  nsHuniiiig  the  pieseiioe  of  a 
D^^tJvc  earbonyl-KToup  in  juxtapoHition  to  the  cnrboxyl-Kroup. 

»Pyroraeeuiic  aci(i  ha.s  all  the  propertirs  characteristic  of  ketones; 
it  yields  an  oximc,  a  hytlnuione,  an  addition-i)rodiict  with  hydro-^ 
c>'iuiic  acid,  etc. 

TIio  eleclroljTBis  of  a  T«ry  concentrated  Rnlntion  of  pot^issiDm  pfro- 

wXn  yioltls  nooiic  acid  nud  diacctyl.    Tliu  formnlwu  of  acetic  acid 

anst  be  looked  upon  as  duo  to  the  liitcractiuti  of  llie  atiioo  of  llie  ncid 

the  hydroxyl-ion,  after  being  di»c)inrgiHl  at  th«  aDOd«  : 

CH. -CO-COO'  +  Oir  =  CH.-CWJH  +  CO.; 

and  that  of  diiicelyl  as  reeuItiDg  from  th«  uaioa  of  tvo  acid  anions, 
witb  etiminailon  at  CO*: 

Oul-Co'cSo'  =  l^H.-CO-CO-CH,  +  »00t 

The  potaaaium  salti  of  other  kotonic  adds  arc  decomposed  by  cleo 
Iroiysis  In  an  analoj^iiB  manner. 

AoetoBoetic  Acid.  CH,  00-CHjCOOH. 

238.  AcdoaeHic  acid  is  a  ;y-kotonie  acid.  It  is  not  of  mueh 
Importance,  but  its  ethyl  ester,  actXoaceiic  eater,  is  a  very  interesting 
ooni}K>und. 

Acctottcetic  ester  is  obtained  by  (Xaisen's  condensation-method 


I  aM»-cBr€aoc;B» 


TW 


«l    tiK 


raft 

TW  krtMW  ilrnwuiiriliiw  ■  •&n«l  br 
Hf  wlb  dJMte  ■^iihwii  acid,  ly  with  m  <HMti 

,  Hi*  |Ww><m>*iBt  atatum,  fmrt»o»  <ft)Pd>,  — <i  aleohJ: 

C»,  aj  CIV  CO,iQH.  _  CH.-00-CH,  +  00,  +  CAOB. 

Iht^atadJktmtS^^"'^  t>^  pla^  "^i™  ■cetaaeelie  ester  is 
hialcd  vMi »  wfy  caocoiUmied  aolBtioii  of  aloohofic  pelarii  or  aoii«: 

*''+^i^+H^1§H'  "  CH.OOOH  +  CH,-CO0H  +  C^OH. 

The  KR«i  importence  of  oeetoAeetic  erter  for  ayntheses  arises 
tnm  i(f  capHhilHy  of  uiuli>ritMnK  thrae  two  decotnimeitioiis,  to- 
gether with  t^H>  laet  that  the  Na-atom  iti  aodioacnnarctic  ester 
oao  bo  nibilJtiiterl  by  a  great  variety  ot  groups.  If  it  is  replaced  by 
a  group  R,  llivrc  b  obtained  the  coinpoiiud 

CH,.CO.CHRCO<Xyj„ 


ACETOACF.7IC  ESTER  SYNTHESIS. 


m 


^hich.  bythckptonp  decomposition.  yiel<Li  a  ketone  Cir,-CO-CH,R. 
this  n>acticm  affording  a  gctu-ral  inctlicxl  of  syntliesizing  melliyl* 
ketones  (110). 
H  Tlie  annpound  cn,-C0-CHK-COOC,H,  can  b*  converted  by 
the  acid  dectimpiwition  into  acptic  aoid,  ami  an  acid  of  tlie  romuila 
RH,C-Cf)OH,  so  that  this  is  a  general  inethiKl  of  preparing  luono- 

Ibatiic  aci^ls  synthetkatly. 
8udium  can  again  react  with  the  compound 


CH.COCHRCOOCjHi, 

with  replacement  of  the  hydrogen  aloni  H,  and  production  of  a 
compound  wliose  Na-atotii  can  also  be  exch&nged  for  the  most 
varied  groups,  yielding  substances  of  the  type 


CH,-C0CRR'.C0OC,H(. 

( are  converted  by  the  ketone  nr  aeid  decomposition  into 
Cn,,CXJ.CHRU'    or    CHRR'aWH. 


■r 


On  aecmint  of  this  pro[)erty,  the  number  of  (^impounilR  which 
ID  bt-  synthi-slz<d  by  the  aid  of  acetoaci-tic  i-ster  ia  v(t>'  great, 
le  pmei-si,  <;ullrd  tlie  atrtotuxlic  m((t  syrUhcsia,  Is  (carried  nut  in 
JH-  way  ain;a<ly  described  for  the  malonjc  ester  synthesis  (186).    A 
*■  examples  of  this  Bynthetical  method  may  be  mentioned. 
I,  M Hhylnonjfl  kftoitf,  the  princijial  conatitiicnt  of  oil  of  rue 
(from  ftvto  gra\toif'ns),  can  be  obtained  by  the  action  of  n-octyl 
Jide  upon  sodioaeetoaretic  ester: 


CH,CO-CH]Na  +  I,CJI„-»CH,-COCHC,H„; 

cSooCiU,  coocyi, 

nd  yields,  by  the  ketone  decomposition,  methylnonyl- 

CH,CO.CH,C,H„. 

>ctyiacotoacctic  ester  yields,  by  the  acid  decomposition,  capric 
arid,  CiflH^O,,  whoso  carbon  ehwn  niuat  therefore  be  a  noniial  one 
(144). 

■  2.  Heptylic  add,  which  is  obtainable  from  d-fmctose  by  the 
eyunhydrin  synthesis  (212,  2),  can  be  synthetically  built  up  from 
ar*--t<^cetjc  ester    by  the    successive  introduction   of  a  n-butyl- 


394 


ORGANIC  CHEMISTRY. 


groiip  and   a  methyl-group;  this  proves  it  to  be  n-butylmethyl- 
acctic  acid; 


CH.COCHNa 

I 

coocyi, 

CH,.COCNaQH, 

I 
COOC,H, 


CH,.CO-CHC.H, 

COOCjH,   ~* 

BuLjIaceloacvIii]  eMer 


Urtti7l!>UtjiM(iMac(T(lc  caur 

tluB  yields,  by  the  acid  decomposition, 

CH.CH.QH, 

coon 

lletfajrl-n-bueylacvlio  aold 

3.  y-Kctonic  aoids  arc  obtained  by  the  action  of  acetoacctic 
ester  upon  the  esti-iB  of  the  a-halogen-substituted  fatty  acids,  fol- 
lowed by  the  ketone  decomposition: 

, R  »     K 

CH,COCHfNa      X|fcH  CH,.C0-CH— CH-CO,CA; 

CO^CjH,       CO,C,H,  ^^0,C,E. 

This  yields,  by  the  ketone  decomposition, 

CH,-CO-CH,-CHa-CO,H. 

4.  When  iodiDo  acts   upon  Bodioaoeloacwtio  mt«r,  the  Bodiam  is 
removeil,  aud  Ibe  two  riisi<luoB  uuilu  thus : 


CH.CO-CHiKii  SftlHC-CO-CH, 

1    I      +J'+      i     I  = 

CO.CH.  CO,C.U. 

OHiOOCH CH-OOLH,-) 

+  2Nal. 


co,c,n.  0 


10,0.11, 

iMoeeiylnwieiNt'c  eMrr  is  rtirmoi,  nnil,  when  tnjled  with  a  20  per  oont. 
ftolntion  of  potassium  CLirboimle.  riMdily  H|ilils  off  curboa  dioxide 
aD(]  alcohol,  with  formatioti  of  cuxtoitykuxttim  (SOSJ : 


cn,  •  CO-  cn— CH"-  co  ■  cii. 

lU     I  IT 


0,HJO.   0 


OH 


ICO. 


C.H, 

on 


CH,-OpCH,.CH,CO-Ca,. 


I«7iiliiiic  Acid,  CH,-COCH,CH,-COOH. 

236.  Ltmndinxc  acid  is  the  simplest  >^-kftoiiic  acid;  it  can  bo 
'obtAJned    by  the  syiitlieticAl  lui^lhod   dcsiTiboii  in  235,  3 — from 
acetoftwtic  ester  by  the  action  of  inonochloroucetic  ertcr;  in  tliia 

I  instance,  in  the  fonnuU  piveii  R  -=  H.  It  was  mentioned  (212, 6) 
that  licviilinie  acid  is  proilucoil  when  hexnses  are  boiled  with  eon- 
centrated  hydrochloric  arid,  and  it  is  usually  prepared  by  this 
method,  which  ha.s  nut  ypt  Iwen  fully  explained. 
l..Eevulimc  acid  i?  crystalline :  it  melts  at  SS'S",  and  boils  with 
alight  decompopition  at  HU)".  It  yielda  an  oxime  and  a  hydrazone, 
and  an  addition-product  with  hydrocyanic  acid;  in  short,  it  exhibits 
aU  the  reacUuus  charactcmtic  of  ketuncii. 


HetoKalic  Acid,  C.I 


^ 


0,  +  n,o. 


H^      237.  Meeoxalic  add  is  a  type  of  the  tiiheim'c  krtimic  acids.    Ita 
constitution  is  proved  by  thp  formation  of  <-f%'  'ncsoxalale  when 

Idibroinoinalonic  estcf,  ItrjC(C(X)CydB)„  is  boiled  witii  baryta- 
Water: 
Mesnxalic  acid,  like  glyoxylir  arid  (233),  ran  only  be  obtained 
with  one  molecule  of  water.  An  ester  of  the  anhydrous  acid  is, 
however,  known;  it  vor>*  readily  adds' on  walor.  The  constitution 
(a>")H),C(On)j  must  therefore  be  assigned  t«  thp  froc  add  (166), 
,.n*hich  has  most  of  tht-  properties  of  ki'toues.  in  the  same  way  as 
lilf>ral  liydratc  (204)  and  Rlyoxylic  aci<l  show  most  of  (lie  rcao- 
Uons  of  nlilehydfs.  When  boiltii  with  water,  rocsoxalic  acid  loses 
irbon  diuxide,  forming  glyoxylic  acid: 


(CgEi,OOC),C  Hr,  +  Ba  (OH),  =  (CH.IK.K;),C(()H),  +  BaBr,, 


^H-C(OH),-CXX)H. 


^ 


is  not  surprising  that  a  compound  containing  a  carbon  aiom 
loAded  with  four  negative  groups  should  split  up  in  this  way;  the 

Ificnmposition  takes  place  more  readily  than  that  of  malonic  acid, 
hich  does  not  low  carbon  dioxide  till  heated  above  its  nieliing- 
ptMnt,  to  140'-1.W. 


Hk 


a^S 


ORGANIC  CHEMISTRY. 


OxiOafetic  Eiter,  C,H,(XX;COCH,0OOC^ 

.  SM.  Oxaia-Ylin  titer  c«a  be  obtained,  ia  AocordAiioe  with  Ci.usbh^ 
mollicMl  (SOS),  b}  the  ooDdensalJon  of  etbj*!  oxalate  witb  etlijrl  aaHlMXx  r 

,ONa ^ 

C.H.OOC-COOC.H.  -  CB,OOC  c(oC',H, +HCC0OCH.-. 


'\ 


tx;.H.      H 


UbjMtxOM 


AddHkM-iinKluict 
wUb  twlliim  vUiuside 


Ethyl  MMMB 


/ONa  11         1 

-•0,H,OCX;-C=CH.OO0O,H»  -•  CH,OO0-C0-  ;CH,-    COOC,H, 

Onl*o«Uo  MUr 

OxjUlMtk  Mt«r,  liku  ttootouixitic  ester,  ckh  bo  split  up  with  addi- 
(Eon  of  oao  molcculo  of  vrator;  tb«  iwo  poiaU  at  irhicb  ilecompocsiltDa 
eaii  rivcur  are  iiidi<»tted  in  the  formula  by  the  doited  lines  1  and  II. 
Dilute  salptiuric  acid  causes  deooiii]>o»llion  at  I,  nitli  fornuitiou  of 
pfmracoRiic  acid  (BH),  carbon  dittxldt*,  and  alcohol.  Decompoitilion 
at  11  rcsuUs  from  tliu  actiun  of  ulknlis,  iitid  yields  oxalk'  and  neotic 
acidx.  The.  kctuiiic  iialuro  of  oxalacolic  e&ter  is  shown  by  tte  fonno' 
tion  of  an  oximB  and  by  other  reactiaiw.  Fro6  oxalacetic  add  is  not 
obtained  by  saponi ncation  of  the  oster,  tiDoe  decomposjiion  occurs. 
It  can,  how«Tcr,  be  nbluitmd  othiTuriao;  il;t  iiivlts  yriih  dccompositioo 
at  173*.  Reiliiutioii  witli  Hodiiitu  aiiiiilgNiu  yiolils  riiiilie  iicid.  and  this 
roaction,  together  with  the  syntbe&JA  given  aboro  and  the  (oriDation 
of  an  oiime,  eatabllshes  the  ooustiiution  of  oxalnoetio  ester. 

Ac«ton«dlcarboxjhc    Acid,   a^OH- CH,- CX>CH,-O0OH. 

290.  AcMontKlicarbtixylio  acid  is  formed  by  tliti  action  of  coocaa- 
tratod  sulphurie  aeid  on  cltri«  acid,  wator^vapotir  and  earboo  ni»D- 
oxido  being  orolvwl: 


CU,.C(X)U 
-OH 


COO  a 


c< 

en. -COOK 
CIlMeactd 


cn..cooH 


=     CO 

I 
cii.-coon 

AneiotwdloMbosrlto  lofd 


+  OO  +  HiO. 


Tills  decomposit  Eon  la  analogous  In  that  andergoiw  by  other  o-bydroxy- 
acidf  into  Aldohyd«.  and  rormio  ncid  or  CO  +  lIiO  at5'|. 

The  coiistittilion  of  nctttortcdicarboxylic  acid  is  inferred  from  its 
forming  with  hydrocynnio  a«id  an  addition-product  which  is  the 
inononitril«   of  citric  acid.     Foar  H-alonu  of  aoetonedlcarboijIiQ 


'^J 


a 


C«' 


C0 


Of 

4U. 


C^a/ 


fAUTOMERiSM. 


•97 


i/fiapiVBMmMiy  n^fia/OtA  \>^  i^oA\\\m;  this  ig  iMpUlnvi)  ^>y  ibe 
I  IB  the  inotecale  of  two  tDDtlirlcao-groupa  in  uuion  witb 
iwgntivfl  groups.  It  Is  thus  powdbls  to  introduce  in  sueccfisioa  four 
(lilTerviit  nuliolns,  wliicli  mnkes  tliu  formatioD  of  uuioorous  deiivii* 
tivcs  fe4isibli;. 

Aoelonedioirboxyllo  ackl  is  cryslnll  iiw,  and  mflw  nl  1$5',  with  loss 
of  two  naolcculw  of  mrbon  Jioxide.  nnd  tnntintioii  of  aet^tone. 

Vitij-Iacctic  auid  (1481  cad  be  obuiined  by  tlie  aid  of  acelAnedioArb- 
ozylte  acid.  It  is  first  Tediic«d  to  jS-hjdroxj'glutBrie  ncid,  wtioio  Oil 
is  then  xiib»tStutc>(I  by  bromine  by  treaiuieiit  witb  conoentr-ited 
hydrobromte  ndd- 

COOH-CH,-rO-cm,-COOH-.COOHCII,rHOH-CH,COOn^ 

Aoownnlicvboiyllc  ocM  S-Hf<1r«xyKluurlc  achl 

-*  COOH.t:H,CHBr.WI,-tXX)H. 

Tho  Bodlam  salt  of  the  tatter  displays  the  property  oomnoD  lo 
/9-tifllogcn-subsi ituted  acids  (ITS).  o[  spliitJQg  off  NaBr  and  C0>;  It 
thua  yields  tbe  deaired  vinyl&cctic  acid  : 

COO  |j^  -CHfCHlBr)  ^H,CO0N»  = 
«  NaBr  +  CO,  +  CH,:rHOH,-tX>OKa. 

Sodium  TiaylBOelMa 


TAITTOHEBISII. 

S40.  Ac«t.oacctIc  ester,  and  in  general  such  substancps  as  1 :  ^ 
which  coritjiiii  the  group  — 1'() — CH,— CX^) — ,  affftnl 
IibUiwps  of  a  rrmojltiible  kind  of  isunicrisni  called  tautoma-imt. 
impound*  of  this  kind  bfhnvc  as  IhotiRh  they  contained  «ome- 
thc  group  namrd .  sfHiiotitnrw  thr  itrmip — ('(OJ^)-CH — CO— j 
few  exainplts  will  serve  lo  nialce  this  elearer. 
Wieii  alkyl-groups  are  introduced  into  acetoacetic  o«t*r  (235), 
become  united  to  a  carbon  atom:  thus,  met hy lace toat-etic 
r^ter  must  have  the  constitution  CH,-CO-Cll(Clf,)-C(X)C^, 
aince  by  the  ketone  decompodtion  it  yields  m«thylethylketoTic, 
and  by  the  acid  decomposition  methylacctic  acid,  or  propionic  acid, 
^ncc  it.  has  this  coiiEtitiition,  the  formation  of  nif>thylnretoacetio 
Eld  18  best  explainetl  by  tnippnaitig  that  KodioBnetoacetie  ester, 
"CH,-COCHNaCOOr,Hj,  is  firat  fonued,  the  N'a-.itoin  being 
then  exchanged  for  a  ntcthyl-gmup  by  the  action  of  methyl  iodide. 
The  majority  of  tsubsUtutioiui  in  aculuucctic  rater  a^c  to  be  tooktHl 


t^S 


ORGANiC  CHEMISTRY. 


upon  as  tttkitiK  pluec  in  this  way,  with  formation  of  C-derivativct 
of  the  cstflp. 

A  different  effect  is  produced  by  the  interaction  of  sodioaocto- 
acclic  enter  and  cMonjcarbonic  ester,  ClCO()C,H,  (24fl),  which  re- 
Bulbi  in  the  funnution  of  two  auliistaiiL-i-s  in  different  quanUttes. 
The  one  formed  to.  eumllcr  quantity  results  by  the  reaction  indicated 
above: 

CH,-CO-CH  » 

\x)OC,Hs 

dnoe  this  substance  is  identical  with  the  product  obt^ned  by  the 
action  of  acetyl  chloride  on  sudiomaimiic  ester: 


CH,  0OCnN6-€O0C,H, 
+  Cl-COOCjHj 


CH,-C0C1  +  NaCH(C00C3nj),  -» CH,00-Cn(COOC,HJ,. 

Its  constitution  also  follows  fmm  its  solubility  in  alkalis,  indieatiug 
that  it  contaiiiis  an  U-atom  replaceable  by  metals.  This  must  be 
in  the  Ctl-group. 

The  main  product  uf  l\m  reaetion  is  on  i»unieric  oc»npound, 
which  is  assumed  to  have  the  cuiistituiion 

ai.C-.CHCOOCjH, 

on  account  of  its  motho<I  of  formation  and  its  insolubility  in  alkalis: 
the  latter  proves  that  it  does  not  contain  a  CH-sroup  betn'ecn  twu 
carboxyethyl-groups.  The  formation  of  a  c(>m[M)und  of  this  typo  is 
best  explain(>d  by  the  iu«uini>ti()T]  tliat  oodiuacet^iaeeiic  est^r  has 
the  coiistituliun  CH,CC0\a):CH-C0OC3H„  as  replacement  nf  the 
Na-atom  in  this  by  the  group  — COOC,H,  would  lead  to  the  forma- 
tion of  a  substance  of  the  above  constitution. 

An  analogous  reaction  takes  place  between  chlorocarbonic  ester 
and  sodioacctylacetone;  the  process  is  to  a  Bmall  extent  in  aoconl- 
anoe  witli  the  equation 


CH,-00-CH 


+ 


Na 


CI 


+  Naa, 


■CO-CH,       CH^'OCHCO-CH, 
■COOC,H,"  CO0C,H, 

«noc  the  compound  formed  is  soluble  in  alkalis,  anil  therefore  ron^ 
tains  a  CIt-group   in   union   n-ith  three  negative  groupe;  vrhen 


TAUTOMBPISM. 


299 


warmed  with  nn  equivalent  quantity  of  caustic  potAsh  it  readily 
splitjc  u[)  inUt  p»ta»iiuui  acttste  atid  acctoac<!ttc  ofter: 


+  H 

CH.-cocn- 


OK 

CO  CH,  =^Cn,COCH,C0OC^nt  +  CH,C0OK. 


COOCjH, 
The  niaiu  reaction,  however,  takes  place  thus: 

CH,-C=CHCOCH,  CH,C=CH  COCHi 

I  ■  =  i  +  NaCl. 

ONa  +  C1-000C,H(  00O0C,H, 

This  is  proved  by  the  infioliibility  of  the  rompeimd  in  dilute  alkalis, 
which  split,  it  up,  even  at  ordinary  tcmpcratureBj  into  acctyiacctooe, 
alcohol,  and  carbon  dioxide : 


CHCOCH,+CO,+C,HjOH. 


I 


CH,C=CHCOCH, 

icyjC^Hj        =  CH,-C(OH) 
+HOH 

This  makes  it>  improlrabic  that  the  gnmp  — CCKXJiHj  la  in  union 
with  a  carbon  atom. 

When  acid  chlorides  react  with  acetoacetic  ester,  it  13  possible  at 
wilt  10  obtain  a  C-dcrivative  or  an  O-iiprivative,  that  h,  a  com- 
pound in  which  the  acid  group  is  linked  to  the  rest  nf  the  molecule 
either  through  carbon  or  through  oxygen.  A  C-derivalive  is  ol>- 
tainetl  by  the  usnal  method — the  trealment  of  sodioacctoacetic 
ester  with  the  acid  chlorida.  When,  however,  acetoacetic  eater  is 
tnixed  with  pyridine  (386),  and  the  acid  chloride  allowed  to  flow 
slowly  into  the  (nL\turf,  aii  CMerivalivo  only  is  formed: 


CH,  CO-CHCXXlCjH, 


COCH, 

C*d<rrl«aci««  itoluijhi  In  alkalf) 


CH,-0-Clia)OC,H, 
O-COCH, 

OxlfrfvKttve  |l"*uluUI«  111  alliKll) 


By  moans  of  such  ambipioua  reactions,  which  chara<!tiTize  many 
other  subrttaiiee.^,  it  iis  not  possible  to  determine  whether  a  body  is 
a  kHv-compriund,  containing  the  group  — CO"CH,'CO — ,  or  nn 
enol-compound,  with  the  group  — C(OH):CH-C0 — .  It  was  for- 
merly Ii|ni8l  to  a:isif;n  one  of  the  two  formulae  to  substances  which 
exhibited  taulonierism,  and  to  explain  reactions  not  in  accordance 
with  this  formula  by  assuming  that  Ininsfumiatiun  had  occurred. 
It  18  now  known  that  «  lautotncrie  suUlancc,  m  th<  liquid  slatecr  in 


300 


ORGANJC  CHEMISTRY. 


soltUion,  cmsisia  of  a  mixture  of  Oic  kcio-eompound  and  the  owf-com- 
pound.  the  proporlton  of  each  present  bi'iii^  dc|«:inli-(il  on  cortaia 
oonditi'inp,  and  this  vipw  AfTnrdfl  a  salisfactory  oxplaiialion  of  the 
observt'ci  facts. 

The  fundairicntal  plienidnftgon  i»  (.hnl  tmiinmers  can  roart  as 
Llumglt  llii-y  coriMstc-d  ivliiiliy  nf  the  krlr>-cfmiin>mi(l,  nr  wholly  u( 
the  eriol-oaifipnuiul.  This  ia  fxplaiiicd  as  follows.  If,  from  a  riiix- 
liiru  oi  two  isoinors  capuble  of  <:lmii;;mf;  into  oni;  miother  with  such 
reailinesH  timt  the  bnlaiuc  bcTwcon  thetn  is  rapidly  rcstorw),  an 
atl-(>iiipt  is  made  to  n>tnovc  one  of  the  coinpnnpnts  by  chemical 
m(!tho(U,  the  jH't'ond  rompoiient  should  beroint?  transfnnned  itito 
the  first,  on  arcoiint  of  the  disttirhancr  (if  the  rquiltbriiini;  the 
iiuxtiire  shtmlil  then  tract  as  though  it  nonBiHti'd  wholly  of  llic  fust 
componeul.  If  a  chfiuk-al  rraK<rnt  which  linly  rearta  with  the 
second  romponent  is  ii«m1.  the  mixture  should  Ix-have.  for  the 
Ranic  n'asitn,  as  though  the  latter  were  the  only  substBiio(>  present. 
It  is,  however,  possihle  to  effect  the  separation  of  taiitomers  l>y 
cheiiiieal  ineans — lirst,  when  the  disturbed  bulunrc  is  only  Klowly 
rcstopcil;  second,  by  R-aclion»  with  nearly  the  same  velocity  for 
both  forms,  rcsiiltiiig  in  difTt-rent  products. 

Tlii-iK  conJilions  nre  lo  a.  ccrtnin  extent  nttniacd  in  the  rciuitiona 
dvitcritiiH)  on  pp.  298  and  299  for  chloruuHrboiiio  estvr,  SciiiFr  cites 
anotltoi' example,  llis  addition  oE  beikz&lanilitic,  C*l)(-N;C.'H-C4U»,  to 
aoeloacetic  ester,  which  also  yiehln  two  JBomeric  suliatancM.  It  ia  by 
no  menoa  certaiu  wlii-llicr  tlio  pTo|wrtiou  vf  lhe>iaoment  formed  ia  th« 
flftme  as  that  or  iIj«  iioiionitiric  fonm  presmu  in  iha  RcetoacclK?  ester, 
WcauH  it  is  unknown  how  far  tho  ubovc  conditious  ore  fulftllod. 

Experience  has  shown  that  the  enol-fonn  gives  an  intense  colour- 
reaction  with  ferric  ehloride.  whieh  is  not  obtained  with  the  kelo- 
form.  Thijs  gives  a  ready  means  of  iitentifying  a  taiitomer,  imd  cf 
recogniKing  the  eonvennon  of  one  form  into  the  other;  it  has  been 
applied  in  various  instances',  sueh  as  the  investigation  of  fortnyl- 
phenylaeeliff  ester.  This  siibstanee  results,  by  Claisen's  cooden- 
salion-niethod  (203),  from  the  action  of  the  ester  of  phenylacetio 
acid  upon  that  of  fortnic  acid : 


"^*  Elhjl  phoaylftreUtc    Ktbyl  fonnjrJptKiijlBMUl«(Eni>rronn) 

Rtirl  formawi  4- 
•odium  athMlJe 


TjIUTOMERISM. 


301 


The  keto-form,  or,  in  this  iiislance,  more  correcUy,  the  "  aldo-fonn/' 
of  tills  substance  has  the  forniuU 


■ 


The  enol-compound  is  solid,  and  molts  gradually  between  60°  and 
70°;  tho  aldocompouiid  is  a  liquid.  In  dilute  alcoholic  solution 
the  former  )ri\'e8  a  dwp  violet-blue  colouration  with  ferric  chkiride; 
the  latter  docs  not  give  any  colour.  If,  however,  equally  concen- 
trated Bolutiona  of  the  enol-form  and  the  aldo-form  are  made,  and 
equal  quaatlties  of  ferric  chloride  added  to  each,  after  some  days 
the  solutions  are  alike,  the  tint  of  the  enol-compouad  having  beeoinc 
lighter,  and  the  aklo-cotnpoiuid  liaving  developi>d  a  blue  colour. 
This  proves  that  after  stanciing  for  an  ititonal  both  solutions  con- 
tain the  aldo-fonn  and  the  eiiol-fonii  ami,  since  the  tint  i.s  the  same 
in  each  solution,  in  c(|ual  anininits.  It  follows  that  an  equilibrium 
between  the  opposite  transfonnationa  exists. 

Other  inethoils  are  known  by  which  this  transformation  of 
tautomers  can  be  rL'cogtuite<l,  of  which  two  inay  be  mcnlioiied. 
Bruiil  lias  shown  tliat  rays  of  light  an-  nmeh  nioru  strongly  dis- 
persed and  refracted  by  Hubstaiiees  containing  a  double  bond  tJiau 
by  their  isomers  which  do  not  contain  sucli  a  bond.  Since  a  double 
bond  n-Jdilts  from  the  t-noliialion  of  a  ketivfonn,  it  is  [xwsible,  by  a 
deteni dilation  of  the  disjwrsive  and  refractive  powers,  to  prove  tluit 
in  alcoholic  solution  enol-conijxjunds  are  trantiformed  into  kelo- 
compfMindK,  ami  vice  rersa. 

W.  H.  Pkmkin.Skn..  haadiscovcrcd  another  aid  to  tlic  invcatiga- 
tJoD  of  these  traiisfim nations  in  the  electromagnetic  rotation  of 
the  plane  of  polariz.aiion.  The  plane  of  a  plane-polarued  ray, 
passed  through  a  tulK>  containing  an  optically  inactive  Ribstance, 
is  rotatCfl  when  an  electric  current  is  passed  thnuigh  a  win-  wduiitl 
round  the  tulw,  enrloMing  tlie  column  of  liquid.  T\w  valw  of  lliis 
rotation  of  the  p!aii<^  of  polarizaiion  is  eliarac:leristie  fur  ehemical 
compounds,  supposing  that  (he  current,  and  the  length  and  tem- 
perature of  the  eolunui,  are  kept  eon^itant:  and  Perkin  found  that 
subslaiices  containing  a  double  bond  in  the  molecule  occasion  a 
much  gn'ater  niiigiietic  rotation  than  their  isomers,  from  which 
such  a  bond  in  absent. 


3o» 


ORGAHIC  CHEMISTRY. 


llie  iave?tigatioQ9  which  have  been  carried  out  have  ipvea  an 
Inaght  into  the  conditions  upon  which  the  kHitaiion  of  an  enol- 
coiQpouiid,  arid  the  ejiolization  of  a  krt<>-r()mp€mii<J ,  n«pe<!tively 
dejteitd:  aiiioiif;  tlipni  is  thi>  tcnipoj-ature.  Cl.iis>:n  found  tliat 
acL'tyldibenzojlniPth&tn?,  CH,(X>-CH(C(X;oH,),  (beii3Mi,vI  =  C,H»C(). 
ej.  886),  hna  tlic  kcto-fonn  at  onlinary  tpinpc-raturcB.  It  is  tlieii 
iiti$o)uhlc  in  alkalJH,  and  in  aqtirnus  finlution  givns  nu  colouration 
with  ferric  ohloride.  When  hratM  to  110°,  ami  quickly  cooled  to 
provenl  irnmoditttc  pc-trariMfonnation,  it  is  found  to  be  converted 
into  the  enol-form,  since  it  answers  tu  the  colour-test  with  ferric 
chloride,  and  is  readily  soluble  in  alkalis. 

It  lias  further  been  shown  ihat  the  nature  of  the  solvent  has  a 
gn^at  influence  upon  thatranafomiatiou.  Ju  solution  tii  chlorafumi, 
an  enol-fomi  will  remain  unchanged  fur  niontlut,  wldlc  in  alcoholic 
solution  it  becomes  partly  or  wholly  tr&i;9formed  into  Ibc  beto- 
form  in  the  course  of  a  few  days. 

pteoue  sebttativeb. 

A  number  of  compounds  which  are  assiuued  to  cent  ain  the  group 
CO 

HC/^CH 

II         |l    are  known;  some  of  these  arc  natural  produeta.  They 
HOy/C'lI 

o 

are  called  pyrone  derivatives.  Some  of  tlicm  will  be  dealt  with  here. 
ChclidonK  acid,  CjU.Oo,  so-CAlletl  because  it  is  found  in 
Cfielidonium  mujiia  (greater  celandine),  funiia  ctilourlffii  aalta, 
CiHi(i,M,;  it  alwi  yields  yellow  sails,  C,H,0,M„  which  are  derivett 
from  an  acid  C,H,0,,  xantkochdidonic  acid;  this  acid,  however, 
when  set  fife  frciiii  itf  salts,  reatiily  losft*  one  molecule  nf  water, 
being  rernnvcrlcd  int<»  eliclidunic  a<rid.  By  boiling  with  uikalis, 
the  hitter  is  split  up  almost  quautitativcly  into  tn'O  molecules  of 
oxalic  acid  and  fme  molecule  of  acetone: 

Otfcllc  anld  Awl  (Hie 

These  facts  are  explained  by  the  structural  formula 

CO 

HC/^CH 
HOOCCv    yC-COOH 


Cbvlidoolc  ociJ 


CHELIDONIC  ACID.  ^0% 

in  accordance  with  which  the  acid  can  be  called  pyronedicarooxylic 
add.    Xanthochelidonic  acid  must  then  have  the  structural  formula 

CO  ,  in  which  the    two   hydroxyl-hydrogen  atoms 

are  also  replaceable  by  metals;  or,  in  its  tautomeric  form, 

.CH,— COCOOH 
CO 
^CH,— CO-COOH 

The  manner  in  which  3HjO  causes  the  above-mentioned  spUttilig- 
up  is  evident  from  the  equation 


H,       O 
,CH;C— COOH  JCR       C— COOH 

X)         ^0  +  3H,0  =  CO        +   ^^g 

\cH:d— COOH  \^H       C— COOH 

CboUdonioMid  H,         O 


Moreover,  a  synthesis  of  chelidonic  acid  corroborates  this  for- 
mula. The  starting-point  of  this  is  acetone,  which  by  Claisen'b 
method  (203  and  235)  can  be  condensed  with  two  molecules  of 
oxalic  ester: 


,CH,     CjHjOOC  ■  COOCjHs  CH :  C  <  ^^^^s 

CO        +  =  CO  +  2C,HaOH. 

^CH,     C,H,OOC  •  COOCjH,      ^CH ;  C<  ^^^jj 


The  product  is  seen  to  be  an  ester  of  xanthochelidonic  acid.  When 
this  is  heated  with  concentrated  hydrochloric  acid,  two  objects  are 
simultaneously  attained — the  ester  is  saponified,  and  one  molecule 
of  water  split  off.  These  reactions  yield  a  compound  with  the  struc- 
tural formula  given  above  for  chelidonic  acid,  and  identical  with  it. 


y** 


ORGMNtC  CHEMISTRY. 


A  pyroiie  derivative  wUicli  has  rfcciitly  attract^^l  attiaition  is 
XH-CCH, 

do       No    . 
\;h=cch. 

It  can  be  sj-nthesized  from  copjKT  acotowHic  fster  and  carbonyl 
chloride  (849) : 


CH.OO         COCH, 


CH.CO  COCH, 

I 


CuCI,+     HCv  ^  /CH 


HC— Cu-CH 

/  \  /  x;o'  \ 

CH,OOC    +CI,      COOCtH,  CjH^OOC  COOCjH, 

CO 


On  saponification  with  dilute  sulphuric  arid,  two  molecules  of  cartwD 
dioxide  arc  eimulianeoiiKly  elimina1«d  fnmi  the  molecule,  90  that 


CH.CO 


«^\xx^ 


COCH, 

;h. 


ibould  result.    Its  tautomeric  form, 


CH.C 


HO  OH 


CCH. 


U 


■I        I 

o 


H 


homever,  loan  one  molecule  of  water,  yirldinfc  dimethylp>'TOQC. 

Dimcthylp\Tonc  i«  characterised  by  the  formation  of  additio«v- 
produets  with  aei<l8,  which  must  be  Iwiketi  iiptm  as  Raliii. 
"salts"  are  formed  by  dissoivint;  dinietliylpyrone  in  an  aqii 
solution  of  hydrochloric  acid,  oxalic  ari«l,  etc.;  the>-  are  ohtatned 
OTstallinc  by  the  spontaneous  evapnraiinn  of  thrar  stilntinns.  By 
^awJving  tJiem  in  a  lar^  qiianlity  of  water,  they  arc  completely 
fayxlrolysed,  so  that  it  is  improbable  that  the  acid  in  them  is  linked 
to  the  carbonyl-Rfoup.  Collie  and  TtrKi-E,  the  diseoverere  of  these 
oompoumU,    accordingly    assume  the  Mranitoiry  »/  Uu    <aygB| 


OXOHIUM  SALTS. 


atom  closing  tlie  carboa  chain,  thus  attributing  to  cHmpthylpyr 


/ 


CII-CCHj 

>< 


hydrochloride  the  stnicttiro  CO  /^^C\'    '^*^*  ^^^  "''"i 

these  compotinds  oxonxum   salts,  on  nrcoiint  of  tlieir  analog}* 
the  ainiiiomum  aa1t& 

These conipounJji can  l>p  jinnprl  tn  lie  tnie  miUk — elertnilylcs 
Xry  various  uicthuds.  It  must  Ix-  rempmlirnvl  tluit  aji  aiiui-ous  aolu-1 
tion  of  diim-thylpypi'iM-  has  a  neutral  reaction  with  litmus,  and  timt 
its  electric  conduct ivity  \s  vcr>'  small.  Thus,  the  oxonium  base  is 
only  feebly  basic ;  its  swUs— if  they  really  deserve  this  tianie — imist, 
therefore,  have  the  prnperties  eharaeteristic  of  tliR  salts  of  a  weak 
baa*.  Thejie  pmprrtip^  fan  be  stiniBied  up  in  the  statpiiieiit  that  in 
arjueous  solution  such  salts  are  hydrolyxed  to  a  high  degree,  or,  in 
other  words,  are  to  a  large  exten)  ?plit  up  into  free  acid  anil  free  base 
("Inorganic  Chemictry ,"  239).  The  aqueous  solution  of  a  dinicthyl- 
pyronium  ealt  actually  has  all  the  properties  which  would  be  anti- 
cipated for  tlie  solution  of  a  highly  hydrolyzed  salt.  In  the  first 
place,  ita  solution  has  a  slixjuply  acid  reaetinn:  the  oxouiuin  salt, 
however,  is  partly  present  aa  such  in  the  solution,  as  Waldex  has 
demonstrated  for  the  picrate  of  dimethylpyrono.  He  compared 
the  qiiantily  of  pienc  acid  extracted  from  its  aqueous  solution  by 
benzene  with  the  quunlity  extracted  after  addition  of  <time1hyt- 
p>'roR(>  lo  the  aqucoua  Rolutinn.  The  latter  pmvetl  to  be  less  in 
amount;  this  must  be  explained  by  HRsuining  the  partial  fonnatinu 
of  a  salt,  whereby  the  quantity  of  fme  picric  arid  in  l.hn  Milution  is 
diminishrtl  (84). 

Hytlndysis  can  alwi  be  detected  by  observing  the  deiitx-wion  of 
the  frcczin^-point.  When  thin  is  dcteriniiicd  for  stibilions  of  pure 
hydftwhloric  acid  of  different  concentrations,  and  subsequently  after 
aildilion  of  dimethylpynHie  to  the  aeid  sniution,  the  depression  of 
the  fiin'/ing-jniinl  in  the  latter  ease  is  less  iliaii  the»um  of  the  de- 
pret«io]i8  causeti  by  the  hydrochloric  acid  and  by  the  dimethyl- 
pyrone  in  their  pure  solutions;  further,  the  difference  between  the 
Value  thus  calculate<l  and  the  value  observed  i»  the  smaller  the 
more  the  solutions  are  diluted,  ae  the  following  example  shows. 
Tlio  addition  of  .1  c.c.  of  normal  hydrochloric  acid  to  10  c.c.  of  water 
caused  a  depressiiMi  of  0X4Q'';  lhi>  addition  of  «'I262  gramme  of 
dimethylp>'rone  lo  the  mixlun*  caiwwl  a  deprewcion  of  0936*;  the 


3if>6 


ORGAKIC  CHEMiSTRY. 


ime  qtiantity  of  dinioiKylpyroiie  dissolved  In  13  c.c.  of  watw 
jwered  the  freezing-point  0- 142'.    Thp  »\xm  of  the  depressions  was 

'thus  0-846*  +  0-142*  -  O-OSS":  the  difftwnop  between  this  and 
the  obaent-d  di-|.rfsaioii,  0-936',  was  tlirnr.fn-  (tO,'i2*'.  Tunica 
1  e.e.  of  hydroi:hJoric  uticl  and  thr  K&nii.-  Cjuanttty  (0*  1262  granunc) 
ofdiiiirtliylj>jTon<?wcrc  Rddcd  to  10  c.c.  of  water,  thcdifferencewns 
only  0-03()',  which  is  in  eoii!i|>lete  aprwrnont  with  the  theon'  o( 
hydnilyiic  di!<8>iiciatiou.  Tho  latter  increases  with  the  dilutiwi;  io 
fact,  a  very  dilnte  snhition  of  dimethylpjTone  +  hydrochloric  acid 
must  behave  at*  thniigb  ihe  two  sutMlanccs  were  not  in  conibinntion 
at  all.  Partial  combination  takes  place,  however,  when  the  solution 
18  more  conccntratt-d,  and  this  causes  a  depression  of  the  freezing- 
poit)t  BtnaUer  than  the  ^iini  (if  the  depressions  obfier\'cd  separately 
for  each  siilmtance. 

Among  the  other  ways  in  whiph  the  salts  nf  dinielhylpynme 
can  be  pri>v»nl  to  Iichave  like  those  of  »  weak  base  may  be  mWi- 
tiom^d  the  eluelric  conductivity  method.  It  was  stated  Utut  a 
solution  of  the  free  base  is  a  Vfiy  bad  conductor;  when,  Ihcic- 

.fore,  the  hydrochloride  is  dissoh'cd  in  such  a  large  amount  of 
water  ft.s  to  be  prsrtioally  eomplet-ely  hydrolyzed,  the  condueti\'ity 
of  this  sohitinn  must  lie  equal  to  that  of  a  solution  of  pure  hydro- 
chloric acid  nf  the  same  molecular  conn'ntralion.  But  if  tlic  solu- 
tion is  not  80  dilute,  an  equilibrium  is  attained  : 


IT  -I-  a'  -I-  C^A  -^  [C\H,0,'H]'  +  a'. 

t>lRMiUi7l|»yMii*    CMIon  if  dlmalhrl' 

pyraiie 


I 


In  this  case  there  is  not  as  great,  a  number  of  free  H-ions,  whicli  an* 
much  more  mobile  than  utlicr  ratioiLs,  and  therefore  conduct  the 
currrnt  much  better.  The  wjnductivity  of  the  solution  must,  therp- 
forr,  be  stnaller  tliau  that  of  hydrochloric  acid  of  the  same  conci-n- 
tration,  and  must  (lecrease  as  the  equilibrium  tends  to  the  ripht- 

1  band  ride,  that  is,  RR  the  solution  beeomes  more  concentrated.     This 

fhas,  in  fact,  been  verified  by  px[)erinient. 

The  power  of  forming  nxonium  salt.'s  does  not  seem  to  l)c  limited 
to  dimethylpymne  and  analogous  cnmiKiundB.  ItAKVtiR  and  Vtt^ 
UGEB  have  shown  that  compounds  rontnining  oxygen,  belong- 
ing to  various  claases  of  organic  Ivxlies.  such  as  alcohols,  aldehydes, 
6st«rH,  etc.,  are  able  to  yield  ci^'st&lline  compounds  with  complex 


OXONIUM  S^LTS. 


307 


ids,  such  as  fcrrcwyauic  acid;  it  is  possible,  ttiougb  uat  fully 
established,  that  tlicac  ore  oxouium  salts.  Tliey  also  atleoipted  to 
obtain  triinfthyloxonium  iodide,  CCHj),0  ■  I ,  anaIogi>u3  to  the  tetra- 
aJkylaiiimoniiirn  salt-i,  Init  vcn--  unBiiccesBful.  Timy  an-  <»f  opiiiluu 
al  Origxard'b  cjtlicr  coiiipniiiids  of  nJkyl  magiiBKiiuu  itiUidca  ^82), 
ch  as  CUiMgl  +  (C,U,),0,  must,  be  n>ganicd  aa  oxonium  deriva- 


C,H, 


'>0< 


I 


Tlie  pi)WGr  of  fontimg  inie  ealts  by  the  addition  of  acids  is  eepe- 
ially  devtdopc^l  in  tlie  aJkyl-cumtioiincIs  of  the  (■Imiiunts  of  the  mtro- 
:ii  group.  Kxaiiipli-s  of  this  arp  also  known  wiili  sulphur 
iiupoiuidH:  au  idkyi  sulphide,  such  as  (CjHjjjS,  can  uuil«  with  an 
yl  iodide  to  form  [C3Ht),[Sl,  trialkylaolijhoniuiii  iodide,  from 
ri  the  free  base  can  be  obtained  by  the  action,  of  moist  silver 
oxide.  It  rt'iiiains  to  be  investigated  to  what  exteut  eleriierit^  of 
other  groups  of  the  periodic  systeui  ar»  capable  of  foruiing  aualo 
goua  compounds. 


CTAHOOEN    DEKITATIVX8. 


Cyanogen,  C,N^ 
i>  V'    241,  When  mercuric  cyanide,  HgCCK),,  is  heated,  it  splits  up 


/  in 


004^1 


into  nicrcur>',  and  a  ^as,  cuanogcn.    At  the  same  lime  a  browu, 
amorphous  polymer,  paracj/anogcn,  (CN')<.  is  formed,  which  is 
verted  im  heatiu^  Ui  a  high  temperature  into  t-ymiogen.     A  belt 
niPthnd  for  tlic  preparalHUi  of  tin?  latter  is  tlu'  interaction  of  wilu" 
tions  of  ]»oljis!uuin  eyanidf  ami  copjier  Kulphate;  cuprir  cyanide  ia 
forniwl,  uod  u<  oitct.-  di;e«m[>o3(-sinlu  cuprous  cyanide  and  cyatiugun: 

4KCN  +  aCuSO,  =  aX^SO,  +  C\i,{CN),  +  (CN),.' 
Tliis  reacUoD  is  aimUiiioiis  to  that  between  putiu«uuin  iodide  and  a 
Bolution  of  copper  sulphate,  in  which  cuprous  ioriide  and  free  iodiire 
are  formed, 

Cj-anogen  is  nearly  relat^'d  to  oxalic  aeid;  when  ammonium 
oxalate  is  heated  with  a  dehydrating-agient,  such  as  phosphorus 
pwitoxidc,  cyanogen  is  prmhiced:  inversely,  when  cyanogen  is  dis- 
solved ill  hydroeliluric  acid,  il  takes  up  four  molecules  of  water, 
with  formation  of  ammonium  oxalate.  These  reactions  prove 
cyanogen  to  be  the  nitrile  of  oxaltc  aeid,  bo  that  its  conatitutioim^J 
formula  in  NsC— CsN.  ^ 

Cyanogen  is  al»>o  soine^^iuit  antilogous  to  the  halogens,  as  is 
indicated  by  the  seeoml  nictliod  of  preparation  given  above.  The 
following  facts  also  stipport  this  view :  potassium  bums  in  cyauoKcu 
in  the  »ame  way  as  in  elilorine,  with  fonnation  of  potassium  cyanide, 
KCX;  when  cyjmoKcn  is  pa.'cwd  into  cauHlic  [M)tash,  [M>tasBium 
cyanide,  KCN,  an<l  pittftssium  cyanate,  KC.NO,  are  pnKluowl,  Uie 
pmeess  being  analogous  to  the  formation  of  pi)tB«diun  t-hlttride, 
KCl,  and  potassium  hypctchlorite,  KCIO,  by  the  artinii  of  ehloriiK-- 
on  eaiwtic  potash  ("  Inorganic  Chemistry."  56).  Silver  cyanide, 
like  silver  ehloride,  is  in  congi8t<^nce  a  cheese-like  sulMlaiiec,  inaJi*- 
ble  in  wat^  and  dilute  acids,  and  soluble  in  ammonium  hydr 


X,  maiii»-     j 
ydroxtdtagj 


HYDROCYANIC  ACID. 


3«9 


At  ordinary  temperatures  cyanogen  is  a  k&s  of  pungent  odour, 
its  boiling-point  being  —20  ■  7*".  It  is  cxctaaivcly  poisonous.  It  is 
stable  at  high  temperatures,  but  its  afjueous  tfolution  dccomjxweH 
slowly  at  ordinary  tempprfttures,  depositinu  a  brown,  amorphous, 
ftiH'ciilfnt  preeipitatp  nf  nzitlmimr  an'ii.  t'yanogen  is  inflwnmabie, 
burning  with  a  peiicli-blrKQuini  coloured  flame. 

Hydrocyanic  Acid.  IICK. 

fi43.  The  salt*!  of  h;fdroc;f(inic  acid  C"prui«ic  acid")  are  formed 
Tii'iK-n  carbnn,  nitrogen,  and  a  .strong  W-^e  are  in  ronlact  at  a  reil 
heat;  fur  esamplp,  by  ?tron?ly  heating  a  mixture  of  carbon  and 
piitttssiuni  carhnnate  in  a  stream  of  nitrogen.  Cf/anidea  are  alao 
pr*wiuccii  wlipn  nitrogenous  organie  substancca  arc  heated  with  an 
,ell;ali  or  alkali-metal  (4>.  Ammonium  cyanide  rehiilts  wiien  am- 
Tnonis'fiaM  is  led  ovlt  rcd-liul  carbon. 

WTien  sparks  from  an  indiici  ion -coil  are  pas&ed  tlirougb  a  inix- 
jtureof  acelylene  ami  nilnigen,  hydrocyanic  acid  is  fornied.  and, 
I  «ince  acetylene  can  be  obtained  by  dJrt^ct  synthesis  (183).  this  reac- 
tion furnisliets  a  nurlliml  of  building  up  hydrocyanic  acid  from  its 
ck'iiientp.    It  is  usually  prepared  by  heating  potassium  ferrocyanidc 
(843)  wiih  dilute  .inlplinric  aeict,  nnhydmua  hydrncyanie  acid  Iwiiif; 
obtaincK)  by  fractifiiuU  diKtillatinn  of  the  a<|iic^ouH  distillate.     It  is  a 
colourlciM  Ii<iuitl  with  an  twloiir  msembling  that  of  bitter  almondu; 
,  it  lioiU  at  26",  ami  in  the  snlid  stale  ineHs  at  -  14". 

When  pun-,  hydmcyanir  arid  ia  stable,  but  its  aqueous  solution 
i  decomposes  with  fonnation  of  brovcn,  amorphous.  in.soluble  sub- 
[slanccs;  the  solution  contain.'  various  conipminds,  among  them 
joaium  fonnalo. 

Like  most  cyanogen  dorivativea,  hydrocyanic  acid  in  an  cxcesaivoly 
daDgeroin  poi«oa.  Tlie  iolialatiou  of  hyilmgcn  pcrniidd,  or  of  air 
oontaiDin^tiblorine,  itt  employed  aa  an  aniidotc.  Its  tozis  effect  de- 
pendt  upon  lh«  dcgieo  of  Innlxntlon.  na  it  dooa  for  the  mercury  ooio- 
poiinda<"  Inorganic  Cbcmiis(ry."  ST4].  .-to  that  it  miiHt  be  (lie  cynno* 
gen  iona  llist  exert  Ibe  poisonous  .<i(.'tt'>ii.  OMicr  cvick-iicv  leads  to  thtt  I 
aame conclusion  ;  ttius,  iKrtaiwiiRi  ferrocTnnidc,  vrhoacuqiieoua solution 
contains  no  cyanogen  tonti,  Is  nan-pobononii. 

Hydrocyanic  aci<l  must  be  looked  upon  aa  the  nitrilr  of  forniic 
acid:  H-COOH -»  H-C\.      Its  fonnation  by  tlie  distillation  of 
iimmonium  formate,  and  the  reverse  transformation— referred  to 


3IO 


ORGANIC  CHEMISTRY. 


above — of  hyclrocyunic  acid  into  ainntoiiiuin  furaiatt:  by  the  lakitig 
Ui>  of  two  molecules  of  water  favour  iIiIm  view,  as  docs  al«>  ihc 
formaUoii  of  liydnicyaiiic  acid  when  chloroform,  H  -CCl,.  ia  wanned 
n-ith  alcoholic  niiiTnonia  and  ca«!<tic  pot4ish  (151).  ilethylamine 
is  obtained  by  reduction  of  hydrocyanic  acid : 

nydrncyanic  acid  is  one  nf  the  weakpst  acids,  its  aqueous  solu- 
tion having  hut.  low  electric  conductivity, 

IlydrocyKKic  acid  Is  preaemc  in  coiisidonible  xmouDls  in  cenaln 
pUiiti;  ii  CAii  b«  otttiunMl  from  a  vegelablo  product,  amt/gdalin, 
CmHkKOi  I,  wh[ch  in  a  gluooaide  4811).  Hud  is  fouutl  in  bitter  itliiHiliilt 
and  other  substances.  In  coatjict  with  w&t«v,  atnrf^Ialiti  15  deootB- 
poaed  by  an  eiLzyiuo  (898),  emulain.  alM  pre.seiu  in  bitter  almonds, 
into  beoEAMchyde,  b}'<lro>cTftni«  aotd.  and  gluooso: 

C„H.:NO„  + 211,0  =  (M1,0+  IK'M  ■»- aC.H./),. 

AiiiyrJAlla  Boiualdctijdi.-  QlucoM 


CyauideB. 

S43.  Thp  (-yaiiidcs  of  lUi?  aUcali-iiieiaU  and  of  tliealkallnp-earth- 
metals,  and  ryaiiide  of  nuTCUry,  are  («)luhle;  other  eyacidre  are 
itisolublr.  All  have  a  gn-at  tendency  to  fonii  complex  salts,  tiiuay 
of  which,  partimlarly  those  coiilaiiiiiiK  alkiUi-nwdals,  an-  scthihlr  iii 
water,  and  crystallijw  wvll.  The  prrparation  and  properties  of 
3i:)mc  of  these  Rails  are  deseribcil  in  "  Inorganic  Chemistrj-,  "  SOB. 

Pota»gium  vyanUk,  KC'X  (or  KCy),  in  obtai'ied  by  heating 
potassium  ferrnryanide,  K,Fc(('iN),  (or  K,FrCy,>,  to  rednesa: 

K,l-e(CN)«  -  4KCx\  +  FeC;  +  N,. 

(Thfi  sjinbol  Cy  ik  sorHeliiiieB  used  to  deunt«  the  radicle  CN.) 

Potasjuitni  cyanide  is  readily  soluble  in  wat<>r,  and  with  difficulty 
in  strong;  alci>hcd:  it  can  be  fused  without  undergoing  dccumpof^it  ion. 
ITic  aqueous  Holulitm  is  unstable;  the  [HitasHiuni  o.vanidc  takers  up 
two  niole('ule:<  of  »  ater,  slowly  at  ordinary-  teiiiperat  iires  and  quickly 
on  boitinR.  with  elimination  of  aiuuionia.  aiid  production  of  potas- 
sium formate: 

KCN  +  2H,0  =  HCOOK  +  \H,. 

Pota-ssuim  cyanide  n.Iways  has  an  odour  of  hydrocyanic  acid,  owing,] 
to  the  fact  that  it  is  dec^onipospfl  by  the  earljon  dioxide  of  the  atmos- 
phere into  this  compound  anil  imtasHimn  earlionate. 

The  aqueous  solution  of  potasauni  cyanide  has  a  atrooKly 


POTASSIUM  FERKOCYMmDE  AND  CYANIC  ACID. 


ill 


ine  reaction,  Ihe  salt   being  partially  hydrolyzed  to    hydro- 
aoic  aciil   anfi    raiistic   pfjliwli   ("InoiiKanic   Clipniistry,"   239). 
Evidence  of  thia  <l«M;oiiiprwiti«»n  \»  alsfi  affonlrd   by  thi'  possibility 
of  saponiTyiiig  cstcre  with  u  solution  of  potassium  cyanide,  titiB  fur- 
nishing at  thi?  same  time  a  nioihod  of  iletormining  the  extent  of 
the  hydrolytic  dcL-oinpoKitioti  of  tlii>  salt. 

PoKis8iwm/(Trocyo»iM?c("  yellow  pnisaialeof  potash  "),K,Fe(CN),. 
stallizea  in  Urge,  sutphur-yt-llow  crj'stjijs,  ■nilh  tUree  molcculia  oE 
atcr,  wliicb  can  be  driven  off  by  the  application  of  gentlu  ht'ot, 
iving  a  white  powder.  It  has  been  stated  (242)  tlial  this  sub- 
:Ancc  is  not  poisoiKuis.  f)n  warniinj!;  with  dthtie  Kiilphiiric  ncid  it 
it-Ido  hydrnryanic  add.  When  heal*-!!  witli  rormrUm/f rf  sulphurip 
id,  carbon  monoxide  is  evolved;  in  presence  of  the  sulphuric 
id.  the  hydnicyaiiic  add  first  foniicd  takes  up  two  innlecnilcs  of 
.■atcT,  with  prDthictioii  uf  uiiinmnia  tind  furmit!  acid,  the  latter 
iuR  i»imediat«ly  docomiHvscd  by  the  cunccntrate<l»ulphiiric  add 
into  carbon  monoxide  and  wat-cr  (88).  This  method  is  often  uaed 
for  the  preparation  of  caHvin  iiionnxide. 

Cyanic  Acid,  IK'NO. 

244.  Cyanic  <urid  is  obtained  by  heating  iUs  jiolymer,  cyamtric 
acid  (847).  and  paseiiis  tjie  n-suiiing  vapoun*  thnHie'i  n  fn-ciiing- 
tnixtiire.  It  is  a  coloiirlrBS  h((Utd,  atabL-  below  VP.  If  tlio  flank 
containing  it  is  removed  from  the  freezing- niixtu re.  so  that  the  tem- 
perature rises  above  0",  vipomiiB  ebullition  bejrin.s,  .sometimes 
econiponied  by  loud  reports,  and  the  liquid  is  ironverted  into  a 
hite,  amorphous  solid.  This  transformation  was  6r!*l  nl}ser\-ed 
y  LiKBio  and  Wohi-kr,  by  whom  the  product  was  ealled  "in-solu- 
ble  cyaiiuriu  acid  ",  or  e-ifamelulf,  which  i.**  a  polymer  of  cyanic  acjtl 
unknown  molecular  weight,  (HCNO),.  It  ha«,  however,  been 
tly  shown  by  StiNiiat  that  the  transformation- product  con- 
ins  only  about  30  ptsr  cunt,  of  eyainelide,  thy  wmainder  being 
cyanimcacid;  these  can  be  geparat#(l  by  treatment  with  water,  id 
which  cyanielide  is  only  vcrv'  spariiutly  soluble,  and  much  les.s  so 
than  cyanuric  acid.  Above  0^  an  aqueoua  solution  of  cyanic  acid 
oluuiges  rapidly  into  carbon  dioxide  and  anuiiooia: 

ncNo  +  n,o  =  H,N  +  CO,. 

ooni^tulion  of  cyanic  ai-Jd  itself  is  unknown,  but  it  yields 
of  derivatives  which  may  be  n^^ordcd  as  being  respectively 


I 

a 
ti 

C' 

V 

ble  c^ 
^f  ur 
Hpecen 
groins 


s» 


ORC4NtC  CHEMISTRY. 


derived  froui  normal  cyame  acid,  C^^j    .  and  from  igtteyanic  acid, 

<z 

Cyanogen  cfJoHde.  CNCl,  may  be  looked  upon  ta  the  chloride  of 
normal  cyanic  acid.  It  ia  a  very  potsonow  liquid,  and  b<iils  at 
IS-S";  it  can  be  oblaJned  by  the  action  of  cliloriue  on  hydrocj'anic 
aoid,«nd[iolymeriz(wn'adily  tocyojiunV  chloride,  CjXjCl,.  Cyau(>- 
geD  chloride  Ls  ntnivrrli^l  liy  the  action  of  caiutlic  potash  into  potatt- 
aiuin  i-tiloridc  and  |K>taa»iiini  cyanatc:  ^ 

CNCl  +  2KOH  =  CNOK  +  KCl  +  HjO. 

Egtera  of  cyanic  acid  have  nnl  been  isoUitcil;  they  are  probably 
fnrmed  in  the  fintt  instaiu-e  by  the  action  nf  nndium  alkoxides  ujion 
cyanogen  ehloride,  since  tlie  polymer,  cyanurif.  rsier,  (CNOC,HjJ„ 
can  be  readily  separated  from  the  reaction^prodtict  (247). 

J^strfH  of  itocyanit  acid,  on  the  other  hand,  arc  well  known,  and 
are  obtained  by  the  aoUon  of  an  alkyl  halide  on  silver  cyauatc: 


OQ:NlAg  +  I1C,H.  -  CO-NC,H»  +  Agl. 

The  Isocyanic  esters  are  volatile  liquids,  with  a  powerful,  stifling 
od'our;  tlie.v,  too,  piilynieme  readily,  yielding  Mocj/anuriic  catcr«. 
8Ucha8(c6\C,H,),(217). 

The  constitution  of  ih*?  ismtyanic  eslers  follows  from  their  deconi- 
positirin  inlu  narban  dioxide  and  an  amine,  by  treatment  with  water, 
or  better  with  dilutir  alkalis : 

CO:  N-CH,  +  H,0  =  CO,  +  NH,-CH,. 

This  reaction  was  first  applied  by  Wurtk  to  the  prcparati<Mi  of 
primary  amines,  whereby  they  are  obtained  pure,  and  free  from 
ficcondary  and  1crtiar>'  aminee. 

It  bna  liceu  stniod  (104)  thnt  primary  amiiiM  can  be  obtained  from 
acid  amidea  by  Uioactioti  of  brotniue and  citustiv  puLaab.  Tliia  is  moro 
economically  effected  by  diiililling  a  mixture  of  Iho  ncid  amide  and 
blenohiR^- powder  with  limo-wntcr.  The  iDeebaiiism  of  tbe  nwctioD 
lian  boi'ii  iiivi-^lie«<<'d  lij'  IIoouewbhft  niid  van  Dobp.  The  fin!  product 
lias  beoti  i8(i[ate«l;  li  jKiLAulwiitiitwl  amide,  with  bruoiiiie  in  uuiori  witb 
nitrnBon  :  li  CO-KH,  —  R-W-NEIBr.  The  hydrogeu  of  the  amido. 
group  rnn  be  ropiiiomi  bjr  metals,  owing  to  ilie  inSti«nc«  of  lli«  afild- 


THIOCY^NfC  ACJD 


3*3 


nsidue.  and  ttiU  ro|)Laeviiiviit  Is  couilderably  faclllMloil  \>y  ihe  intro- 
daciioD  o[  8  Br-atom.  Tbo  caustic  putjish  prtscnt  cfkiiMsa  thv  (urmu- 
tton  of  A  compound,  R-CONKBr,  whlcti  is  uiisUblo,  biU  onn  be 
isolated.  Tbie  pot-fueium  broivAiii idc  rundllj'  iinilergo««  Ati  iolra- 
roolecixlar  tr&UKrorniAtiun,  similar  Ui  tli«  Beckmann  irftngfornialion 

ait): 

K— N— Br  R— N— U 

I  changes  to 

0=6— R 


0=C-Br 


bromBinldr 


This  traDBfortnatiuii-produot  Io»ea  EBr,  with  lorniatioii  of  an  Uo* 

N  R 
evftsic  ester,     ||     .  whioh  ia  deootapOMd  by  lb«  ««t«r  pmoot  Into  it 

00 
primary  amine  and  Od. 


Thiocyanlo  Acid,  HCNS. 

Z4&.  Thiocyanic  acid  (BiUpfwci/anie  and)  resembles  cyanic  acid 
in  ita  propertipa,  but  is  much  niuw  slalilp  towards  watf  r.  Il  nan 
be  obtained  by  treatment  of  barimn  tliitwyaiiale  with  tlie  calculjited 
proportion  of  dilutt-  sulplmric  acid.  When  the  sulution  is  fraction- 
ated under  diintmslicd  pnissiire,  and  tlie  vapimr  passed  over  ralciuiii 
chiciridi-  1o  free  it  from  water,  iiilo  a  vcs^'I  cooled  by  a  frctaiiix- 
mixturc,  the  anhydrovis  acid  in  obtained  in  the  form  of  a  vorj'  vola- 
tile. pimsent-smpUiitg  Ii(|uid.  which  nhangcK  quickly  to  a  solid 
polymer  after  removal  from  the  frepzing-inixtiin'.  Whcji  warmed 
with  dilute  sulphuric  acid,  thiocyanic  acid  takca  up  one  molcriilc 
of  "ivater,  and  decomposes  similarly  to  cyanic  acid  (244),  with 
production  of  carbon  oxysulphide,  COS,  instead  of  CO,: 

HCNS  +  H,0  -  H,N  +  COS. 

Jhtassiutn  thiociiaruile  i5ut>[Aiuvd  by  twiliii)CHHolutioao(  potiusiiini 
oyanide  vilti  siilpliur,  Amont;  oibur  upplicntioriK  It  U  uusl  iii  Voi^ 
BAUD'S  method  vf  silvcr-Litratioii.  When  silver  uilrutc  it  added  to  ii 
■olation  of  potasEiam  tbiooyiinate,  sUtxr  thi'jcj/artate,  AgCNS,  ia  de- 
poeited  in  tbe  forna  of  awhile,  cheeee-like  precipitate,  iciAoIuble  indiluto 
mlDoral  aeidi.  Fenic  thiocyatmit,  Fc(rX8)i,  has  n  dnrk  blood-red 
colour  :  its  furniutioii  is  usi-d  as  n  test  for  ferric  anils.  Tho  red  colour 
is  due  to  [he  D<iii-ioiiized  niolDCulM  Fp(CIfS)i,  since  neittjt^r  the  forric 
ion  nor  the  thiocyanic  ion  are  coloured  in  Bolutioo,  and  the  colour 
is  intensified  if  ioniiation  is  dimiuisbed,  for  example,  br  the  addition 


314  ORGANIC  CHEMISTRY. 

tit  more  or  lli«  r«rric  uilt  or  of  th«  thlocfanate.  Tbe  red  coloor  is  r^ 
moved  \>y  sbnkiDg  op  with  cth«r,  wIictoas  loos  cannot  be  extracted 
bjr  this  meHris.  Mtrcury  Clilocjtanat*  lias  tbe  properly  of  s««ltiDg  up 
when  deflomfKwed  b>  lieat  ('*  Pliamoh'a  serpeots  ">. 

The  constitution  of  ihiot-yame  acid,  like  tliat  of  cyanic  acid,  is 

unknown.  miJ  it  ruscmblcs  the  lattor  in  giviiig  ristr  to  two  wrics  of 

a,  o 
esters,  tlie  f/iiWj^nu;  esters,  C<\t'    ,  and  tbe  iaolkioq/anic  caters, 


• 


Thiocyanic  eaters  are  obtained  by  the  action  of  alkyl  iodide* 
upon  the  salts  of  thiocy&nic  acid: 

CX'S1K"+1|C,H,  =  CN-SCjH.  +  KI. 

They  are  liquids,  insoluble  in  water,  and  characterized  by  a  leelt- 
Kke  odour.  That  the  alkyl-group  in  these  compounds  is  in  union 
Tnth  sulphur  U  proved  by  the  nature  of  the  products  obtained  both 
by  n_'iiuct ion  and  oxidation.  Rrdut'tioii  yields  niercaptami  anil 
hydnjcyaniL-  ai^id,  uielhylamijiu  Lwing  obtained  from  the  la(t<^r  by 
further  reduction: 

CN.S(V1,  +  2H  =  CXH  +  HS-C^,. 

Alky l-sul phonic  acids,  such  as  CjHcSOjOri  (68).  are  obtained  by 
oxidation: 

Under  the  InBuencc  of  heat  the  thiocyanic  eetcis  are  trans- 
formed into  isothiocyanic  esters;  thus,  diatillation  of  allyl  thi«- 
cyanaie.CX-.-^^jHa,  brinjts  sbuut  this  cliaiige. 

The  isotliiwyaiiic  esters  arc  also  called  mutlard-oHs,  after  allj't 
isothiQcyanate,  to  which  tlie  odour  and  t^aste  of  niustard-siitls  are 
duL'.  Tlie  following  rfaelioiis  prove  that  IhciC  cotnpounds  contain 
au  alk>'l-group  in  uoioii  with  nilruKcn,  luid  have  the  coiustitution 

cCii      '    ^^^  treated  with  concentrated  sulphuric  acid,  they 

take  up  ir&tcr,  yieldinf;  a  priiaar>'  amiDC  and  carbon  ox>'8uIpbide : 

RNiCS  +  II,0  -  RNH,  +  COS. 

They  are  converted  by  reduction  into  a  primary*  amine  and  trithw' 
melkylau-,  {CH^)j.  the  lotted  probably  resulting  from  the  polymeri- 


FULMINIC  AOD. 


3'5 


ifttioQ  or  the  thiomethylene,  CH,S.  first  fonned,  wliicli  is  unknown 
in  the  free  8tat«: 

RN:CS  +  4H  -  K-NH,  +  CH,S. 

AtMitioii- products  of  the  miistaril-oils  uill  be  described  lat^r  (254 
luid  255), 

Cjonimif/f,  CN'NH,,  ja  (]htain<-<l  in  varinus  reactions;  for  in- 
stance, by  the  action  of  ammonia  upon  cyanogen  chloride;  it  is  a 
crystalline,  hygroscopic  solid ,  and  polymerizes  readily.  I  ts  hydrogen 
atomR  can  be  replaL-pd  by  metals;  for  ('xample,  silver  yields  eilver 
cifanamitlf,  CN'-NAgj,  which  is  yellow,  and  iiisohiblf  in  dilute 
aniinoniuiii  hydroxide,  wherein  it  difTers  froni  tlie  majority  of  alver 
oompounds. 

Fnlminic  Aoil 

M6'.  Salts  of  j'ulminie  acid  aro  obtained  by  tbo  interftction  of 
mercury  or  xilVRr,  iittrlc  acid,  and  alcohol,  in  certain  proporlioru. 
Tlic  h«3t  known  of  thew  is  mervury  fulminate,  HgOiStO.,  which  is 
pnt])arH(l  uii  ii  lar^  ih.'1)1«,  Hiitl  emi)loyt'd  for  fltiiiig  i>vvc:ti6'«ic>ii  caps, 
and  for  other  pnrpoec^.  )t  has  boon  monlioiicd  (S31)  that  gunoolton 
cau  lie  expkxJec!  l>y  ihe  detonatioa  of  n  amall  qiuintity  oi  this  sub- 
•taace;  and  it  [miduces  Ihu  ftami:  rcauU  iritli  ol)ii-r  e>i|)losi <'««.,  »»  that 
I  lie  aoK-jtlled  "  fiiltulnatinK  mercury"  |ilay»  an  i![n|x>rt«nt  part  In  their 
applitntion, 

tiilefr  Aiin^iiiott,  Ag(ONO),  ia  mucli  more  explosive  than  the  mer- 
cnry  salt,  uuA  bene*  i»  hm  «iuplQye<l  teehnioally.  The  exploeioti  of 
th«si>  «all8  bfl»  a  hriaaut,  ihoiiKh  only  IiichI.  effect ;  ihia  enabled 
HoiCARn,  tbc  diacovcrcr  of  moroiiry  fulminar«,  to  i^xplodo  a  unial) 
quaiitily  in  abuUoou  williotit  injur}'  to  the  latter,  tire  only  effect  hejng 
to  shatter  the  leaden  sliells  cnntainmg  the  expIosiT^, 

Tree  fulmiatc  acid  is  a  very  unMabte.  volatile  Hiihatnnce ;  it  hait  an 
odoiir  resembling  tbat  of  hydrocyanic  aeid,  and  is  L-xces^ively  poi- 
aoiiuus. 

According  to  Net,  the  fotnnula  of  rulminic  a«id  is  C=N-OU,  cftn- 
taining  a  divalent  carbon  atom;  when  mercury  fulminate  is  troaled 
Willi  acetyl  chloride,  a  compound  of  the  forioulB  CII)-CO(CNO)  isob- 
taiued.  Iniireaeneeof  hydnwliloricncid  llie  fiilmiiiHte  lakes  up  water, 
with  formation  of  hydroxy littuiix!  and  fnmkic  acid.  It  is  converted  by 
bromine  tato  a  compound,  Br,C(NiO*,  nilti  the  coual  iculfoDal  formula 

Br— C=N-^0 


i 


Br-C=N-0 


316 


ORGANIC  CHHMtSTRY. 


CyaDuric  Acid  and  IiocjaAaric  Aoid. 

247.  Cyamirie  Itromide,  C,N,Br,.  is  obtained  by  hcatinp  potas- 
gium  fprricyanidp  with  hmminp  at  220°.  By  hoatirK  '■'^i^l'  water, 
the  bmmide  is  converted  into  cyanuric  acid.  (CNOH),,  The  lattor, 
however,  is  usually  prepared  by  the  action  of  heat  on  urea  (252j. 
Two  series  of  esters  are  derived  from  this  acid,  the  normol  and  the 
uocijamiric  fit/era,  tlie  former  being  called  "  O-tsters,"  anil  tlw-  latter 
"X-osterff." 

The  normal  cyaniirio  estenj  an>  obtained  by  the  action  of  Ro<liura 
alknxides  on  pyaniirir  ehloride  or  bromide.  The  fomiaiinn  of 
aleohol  and  ryanuric  acid  on  saponification  proves  the  Bikj'l-groijp 
in  thpsic  estrrs  to  Im-  in  imion  with  oxygen ;  for  this  rconon  constitu- 
tional funimlu  I  Ui  asKJgnc-d  to  tlicni. 


N 


I. 


V 


n. 


RN.      ,N.R 

do 


6R 


The  isocyanurie  esters  result  when  silver  cj'anurate  is  heated 
with  an  alkyl  iixlide.  Tlit-ir  alkyl-group  is  linked  tu  nitrogen,  since 
on  boiling  with  alkali,  th«'y  yii'Id  a  priirian,'  aiiiinp  and  (rarbim  di- 
oxide, a  deeomjJOMitinn  accnuntpd  for  in  conntituiional  formula  II. 
The  0-eRteni  am  formed  when  an  alkyl  iodide  reacta  with  mlver 
cyainirate  at  onlinary  trmprraturrs,  but  their  conversion  into  the 
N-e«tcrs  when  heated  explains  tlio  difference  in  the  products  ob- 
tained at  ordinary  and  at  elevated  icmpcralures. 

Ki-Asos  iiflfi  wifyi^'stetl  that  cyamelide  (S44)  is  t»ocyanurie  aelil, 
and  is  ri'Iated  to  ilie  isdcyaiiuric  esters  in  the  same  way  as  cyanuric 
aeid  is  related  to  the  normal  cyanuric  esters.  The  fomiatiou  of 
i-yanurie  ehloridtr  by  the  aetion  of  phosphorus  jwntODhlori'lr  iin 
thi^  normal  esters  and  normal  cyanuric  acid  and  the  fnci  that  the 
tso-oHtera,  and,  as  Senibh  has  recently  shown,  cyaniolide,  do  not 
yield  cliluridGS  under  this  treatment.  8Up|xvrt  this  view. 

Important  evidence  in  favour  of  the  ImintKfornLula  for  cyanuric 
acid  has  been  furnished  by  Chattawav  and  Wadmore.  who  Iiave 
succeeded  in  repWinK  the  iiit-tal  in  potassium  cyanurati*  by 
clUorine.    Tlitiy  n-gard  the  compound  formed  aa  (0:C:  N  -CI),. 


DERIVATIVES  OF   CAfiBONIC  ACDK 


"248.  Carbonic  acid.  H,CO,  or  CO(On),.  is  not  knon-n  in  the  Tree 
state,  but  i8  supposed  to  exist  in  the  solution  of  carbon  dioxide  in 
wnter;  it  lieoomposcs  vory  reailily  into  its  ai)}iydridE>,  carlM)n  i.!i- 
oxide,  and  WEt«r,  It  is  dibasjc;,  and  is  gi'iK-rally  described,  with  its 
saXta,  in  inorganic  tlwinistry  ("Inorganic;  Chtinistry,"  I84j.  Some 
of  its  organic  derivatives  arc  dcalb  with  in  tluti  section. 

Carboayl  Chloride.  COC'l,. 

849.  Cwbonyl  chloridf-  (phoagtne)  ia  obtained  by  the  sctioii  of 
chlorine  on  L-urbon  munoxldo.  It  was  called  phosgene  by  Sir 
HriiPHRY  Davy,  under  the  impression  that  it«  formation  by  this 
means  cnn  only  tnkc  place  in  prrsonce  of  sunlight,  a  view  sinoe 
proved  to  Ije  incomrt.  Ciirbonyl  chloride  is  a  pas  with  a  powcrlul, 
stifling  odniir;  its  solution  in  benzene,  in  whicli  it  is  readily  solu- 
ble, is  a  cotiunerLnal  product.  It  Is  employed  in  s>"iithi'«e8,  both 
in  tile  laliorat-ory  and  In  the  arts. 

The  rraetion.s  of  earljonyl  chkiridp  iiiditatn  that  It  is  the  ehloridc 
of  carhoniip  acid.  It  is alowly  decompo*e<l  by  water,  yielding  hydro- 
chloric acid  and  carbon  dioxide.  With  alcohol  at  ordinary  tem- 
peratures it  first  forms  citlorocaritonic  cater; 


a 


By  more  prolonged  troatment  witli  alflobolt  And  also  In*  the  action 
of  sodium  nlkoxidc,  carttonie  eater,  CO(OCjHj)„  is  product-'d.  By 
the  action  of  ammonia,  the  two  CI-atoin3  in  carbonyl  chloride  can 
be  replaced  by  amid<j-Krou[js,  with  formation  of  the  anii([e  of  car- 
bonic acid,  urea,  (XXNH,),  (288).  AU  these  reactions  are  charac- 
teristic of  acid  chloride.'^. 

Hie  vlilorocftrbonic  c«t«r«,  alao  c«ll«d  Mion/ormfA  esters,  art  ool- 
ourIe«  liquids  of  strong  odour,  uud  dislil  without  decompoMitlon.  The; 


3»8  ORGANIC  CHEMISTRY. 

arc  cniplojrcd  for  the   inlrodncllon  of  tli«  group  — OOOCilti  Into 
oumpounds  (UO). 

Ttio  cnrboiifc  cs(«ni  Are  nlso  liquids,  but  are  characterixed  by  the 
pottttcwtiori  or  nil  (tllivroHl  odour  ;  thoy  ure  insolable  in  «rtt«r,  and  ars 
Tsr;  rradil;  aapooiBed. 

Carbon  Dtralphldt,  CS,. 

250.  Carbon  diftdphide  is  manufaclured  synthetically  by  passing 
tulphur-vapoiir  over  red- hot. carbon.  The  crude  product  has  a  very 
disaim'oablo  odour,  which  can  be  removed  by  duttJlUn^  from  fai,  the 
pure  product  being  an  almost  colourless*  liighly  refractive  li<)uid  of 
pthcrcal  odour.  It  is  InsolubFe  iu  water,  boils  at  46^,  and  \ita  & 
specific  gravity  of  l-2{i2  at  20".  Carbon  di-sulphidt;  is  poisonous^j 
and.  as  it  is  hij;Lly  inllaniniablr,  miist  \>k  handled  with  ea-at  rare. 
It  is  an  excellent  st>lvent  for  fats  and  ()il3,  and  finds  extensive  appli- 
cation in  the  cstraction  of  those  from  seeds,  It  is  also  employed 
in  the  process  of  vulcanizinj?  indiarnhber. 

Carbon  disulphide  is  a  stable  compound,  nml  resists  the  action 
of  heat,  although  it  is  an  endotberrnic  substance  (*'  Inorganic 
Chemistry,"  119).  It  is,  however,  possible  to  make  its  va|>our 
cxpli»de  by  means  of  mercury  ftiiniiiiate.  The  halocens  have  little 
action  tin  it  at  ordinan,-  tempera turos,  but  in  presence  of  a  halogen- 
cnrrier  chlorine  and  bromine  can  effect  substitution,  with  pro<luc- 
tion  of  carbon  tetraehloridc  and  tetrabromide  respeclively. 

Carbon  diinilphidc,  like  carbon  dioxide,  ia  the  anhydiidc  of  an 
acid,  or  an  anhydrosulphide.  With  alkali-sulphides  it  yields  tri- 
thiocarbonatea: 

TiaS  +  CS,  =  RaCSj. 

lUriimt 

(I'll  blacarbaOB  la 

Tliis  barium  salt  is  yellow,  and  diasolvcfi  in  cold  water  with  difficulty. 
By  the  addition  of  dilute  acids  to  its  sails,  frw  triihioearbonit  acid. 
H^Sj,  CAn  be  i>blain('d  in  the  form  nf  an  oil  which  dt-composcs 
rradily.  The  pota.<tKinni  salt  is  (nnployed  in  the  destruction  vf 
vine-lice. 

The  potassium  salt  of  xnnthic  acid  is  foraicd  by  thcr&ction  <if 
potassium  cthoxide  on  carbon  disulphide: 

CS.  +  KOC^H,  -  CS 


CARBO}}  OXYSULPHIDE  AND  UREA. 


3>9 


Thi$  is  effectecl  by  sliaking  tip  rarbon  disulphirte  witli  a  solution  of 
caustic  potash  in  absolutf  alcohol,  when  potassium  xantlia1*  sepa- 
rates in  the  form  of  yellow,  glittering  needles.  Free  lantliic  acid 
b  verj*  unaUble;  it  owes  its  name  {^urcfros,  yellow)  to  ita  cuprous 
salt,  which  has  a  yellow  colour,  and  resulte  from  the  spoiitaiicous 
transforinaliou  nf  ihebruwnish-Uack  cupric  salt,  precipitatwi  frtmi 
a  siilutioa  of  copper  sulphate  by  th«  addition  of  a  xai]that«. 


Carton  Oxysulphide.  COS. 

261.  Carbon  oxysulphije  is  a  coioiirlofiB,  lodoiirloas,  inflammable 
ga«.  aiul  it;  ubiainrd  by  tht^  action  of  sulphuretted  hydrogen  od 
Uoryanic  esters ; 

2C0-NC^.  +  W^  =  COS  +  CO(NIIC,n»),. 

Mpniion  haa  b(^n  made  (246)  of  it£  formation  from  liothiocyanie 
esters.  It.  Is  also  produced  when  a  mixture  nf  carhnn  monoxide 
and  sulphur- vapour  \»  pussied  thmitgh  a  tube  at  a  ntiHlerate  heat. 

Carbon  nxysiilplildocitu  also  tw  obtaiiiMl  Ijj-n  romiirkublu  roaoiioo  ; 
when  cnrboD-disalptiido  rapour  is  piuswd  over  nid-bal  kaolia  (aluini- 
tiium  wtit»t«l,  wliioh  pliiyH  tlte  pnrl  uf  au  oii<lizing>agieDt,  on«  S-»tom 
of  itic  (TSt  is  replaoed  by  oxygen,  and  siliooa  disulpbido,  BiSi,  siraul- 

Carbon  oxj'siilphide  is  but  slowly  absorbed  by  alkalis.  It  yield* 
salts  with  tiictalhr  alkoxide.s;  the,se  may  l)e  looked  upon  as  derived 
from  c&rbonatea  by  sinmltaneoiis  exchange  of  oxygen  for  sulphur: 

COS  +  CjH^-OK  =  CO 

trt.  co<^[J;. 

252.  Urea  owes  Its  name  to  itd  occurrence  in  urine,  as  the  final 
4Jeromp08ition-pnKluct  of  the  albumins  in  the  l>ody. 

An  adult  «xcret«s  about.  1.500  gri-ftnimrA  nf  urin<>,  contniniiig  ap- 
proximamly  2  t)rr  cent,  of  urea,  in  iwi-iity-four  houra,  &a  that  tb« 
daily  produolioii  of  itiU  aubAtin(>e<  nmoimta  to  about  80  gr»mEuca.  To 
obtain  utva  ft'nm  urine,  th«  latter  is  flret  coiKwntrMpd  by  evapora- 
tion.  att«r  whicb  nitric aoid  is  atldad  ;  una  nitrate,  CO<MUi)i '  IIMOi, 


3SO 


ORGAHIC  CHEMISTRY. 


^- 


(SMjisfireelpitnteil.  and,  on  account  nf  impuTities,  luumjoUon  colour. 
Tbesc  wlourtng-mattfln  Kix- rcmovcO  b>  dissolving  the  precipitato  in 
wataranil  oxiilixing  them  with  polasiiiuni  pemmui^uate.  The  urea 
is  Mt  free  from  the  Aolution  of  the  nitrate  by  treaUneiit  with  b&riuni 
cnrbouiLtti: 

SCON.n.HKO.  +B&CO.  =  SCON.H.  +  Ba(NO.).  +  H.0  -l-OOi. 

UTfla  nllniUi 

On  «vn[Kinitiuii  to  dryiiMS,  a  mixture  of  ure»  and  barium  nitrate  is 
obtAined  from  which  tho  or^nic  cotnpoand  can  b«  M)>anitcd  by  solu- 
tion in  strong  kIcoIioI. 

It  has  been  stak-d  <24&)  that  urra  is  to  be  looked  on  as  Ihe  amide 
of  carbonic  acid,  ou  account  of  ita  formation  from  the  chloride  of 
this  acidf  carljonyl  chloriite,  OOCIj,  thU  reaction  proving  its  cotistl- 
tution: 

jCl      HlNH,       /XH, 

+  =  TO        +  2Ha. 

XjCl      H[NH,         ^NH, 

OMrbonrl  ohlorlda  Upm 

A  coDfirmatioQ  of  this  view  of  tho  oooRtitution  of  urea  U  its  fomift- 
lion  by  ilio  &c.{\nn  of  ammonin  on  rarbonio  c«ter. 

Urea  i«  foraictl  by  mlililion  of  aiitmonia  to  iiwcyanic  acid: 

^^  NNH, 

Ammonium  isocyanate  dissolved  in  wa1«r  is  transformed  into  urea 
on  evaporation  of  Ilio  solution.  This  is  the  method  by  which 
WoHLEB  ufT<*ct*d  his  clasac  synthesis  of  urea  (1). 

ThiB  reaolion,  vrliioh  has  an  important  iMiring  upon  tho  bistorf  of 
orjciitno  (^hi-iiilDlry.  has  Ihkih  sludind  in  deiail  bjr  JAKiai  WdUtEB  and 
Hamiii.v.  Thpir  researolies  have  shown  that  the  reveise  traoiifonna- 
tion  of  iirra  into  unimoniuni  ittwyaiintv  occun  also,  ainoe.  on  ailditioo 
of  silver  nitrftC«,  a  solution  of  pnro  nnm  in  lioillDg  watar  jrlelds  a  pre- 
cipitate of  silver  cyanato.    An  f.-quitibnum  ia  sttniaed : 

O0(NH,)f;::O0K  HH4. 

Ur^  An-mi'iium 

THien  thin  ia  rpactied,  the  solution  only  contains  a  rmy  Hnall  percan- 
tagA  of  iiLoeyanatG.  It  is  almost  ind«p«ident  of  tho  tmnperaturs, 
proTiiig  ilint  lii«  trniisfonnalion  of  the  snlrms  into  one  another  It 
aocompaiiied  by  but  slight  cnloriOe  effect  (tOO). 


UREA. 


3»» 


The  following  is  a  proof  tbut  tti«  formatioD  of  nrca  i«  occasioned  hj 
tbP  iiKvnuitioH  of  lfHt>ioiig  and  CON-iORS.  Ttie  reaciion  would  Iw 
DRimolcculor  if  it  wcrv  eauwd  by  molfrciilcs  of  anDmoniam  iflooysoate, 
j<nd  if  it  were,  on  tbe  other  hand,  a  reaction  between  ion*,  ilii*  Telocity 
equation  for  bimoleoular  renctiona  (101)  wcmld  n)i|>ly  ("  laorganlo* 
Chemistry,"  Bli.  ax  i*  ac'ualty  i)i«  caar.  It  haa  nlNn  Ix'en  ohaerrcd 
tbitt  addition  of  both  animoituiai  Hiil|)lintc  CKIl.<ii>ii4)  m\A  voinulum 
ttocyauatc  >(CNO>iuiiH)  aot'elerm ff!(  xhn  tniiiHlorinalion  into  nwn  by  an 
timouDt  equal  to  that  deduced  from  the  liiore&se  in  concontracion  of 
the  iona. 

853.  It  was  tnentioned  (244)  that,  isocyanic  esters  are  decom- 
posed by  water,  with  formation  of  primary  aimnos  and  carbon 
dioxide.  If  the  primary  aniine  formed  is  brought  into  contact  with 
a  second  molecule  of  isooynnic  ester,  addition  tftlccs  place,  with  pro- 
duction  of  a.  tymmetricai  dialkjfl'Urea : 


CO:NR  +  H,NR' 


/NHR 

CO 
Nkthr' 


This  is  a  general  method  for  preparing  symmetrical  dialkyl-uiras. 

A  mottoalkj/l-urva  is  obtained  by  the  notioH  of  ammouin,  instoad  of 
ao  amtae,  upou  «u  inoeyauic  astur. 

yNRR 
Unafmrnftrieol  dialkfil-urea*,  du  ,  nn  prepared  by  tbe  letlon 

of  tfiocyanic  acid  on  secondary  aminos;  tho  method  of  procedure  is 
analogous  to  that  employed  iii  WuHLCit'ssyulhesiaof  urira,  andoonsiata 
in  warming  a  aalution  of  ttie  isocyanat«  of  a  eocoadary  amioo : 

CONIINHRB'  =  CO 

The  uiisytuuK'trical  dlnlkyl-ureaa  are  converted  by  treatment  with 
abaoluto  (lOOX)  nitric  acid  into  nitro-oooipounds.  which  wore  dia- 
eoTered  bj  Fbanciiixonx  and  are  cAllod  nitramwa : 

Urea  crj-stallizcs  in  elongated  prisms,  the  eiyslal*  resembling 
those  of  potassium  nitrate;  they  are  very  aoliible  m  water,  and 
melt  at  132°.  Like  the  amines,  urea  farms  salbj  by  addition  of  one 
molecule  of  a  monobasic  acid:  of  these  the  ttUraie,  CON,H.'KNO„ 


S" 


ORG/1  WC  CHEMISTRY. 


and  Ibc  oxalate,  2C0NjH,C,H,0„  di»<xj|\«  with  difficulty  in  solu- 
tions of  the  currospoading  acids. 

lu  noma  of  its  rcuitious.  porlioularlj   i&  eertaiii  ooadfinsatioD- 

pnMCUU,   uro*   bcluivM   u  thougli  it  li«l    tli«  itruotan  C~OH. 

\Nir. 

An  cllic^r  of  thii  itourta  Is  obtained  br  udditinn  r>f  moth^l  ulcohol  to 

ojanniiildv,  tlio  rOkCLioti  being  faoililaled  by  tho  preWQM  of  b;dro- 

ehlorio  acM  : 

^N  yOCK, 

0         +H00n.=  0=NUi/    ■, 

CTanunUs  ll«ttijllttuiirM 

This  method  of  formAiioo  indicntcs  tlia  coDstitution  of  the  com- 
poand,  whidi  csii  also  be  deduced  in  other  waj's,BiicI»  as  llie  production 
of  inelliyl  nlilonde  on  Iieating  willi  hydroohlorio  &oid,  which  iadicAto 
thitt  Ibe  ClU-group  Is  not  In  uiitoo  viiii  nitrogen,  since  tinder  this 

/SH. 
lraalin«iit  niftfti/titTfa,  CO  ,  splits  off  methyUimine,  ClffyHs. 

\snoH. 

Whfn  heated,  urea  melta;  it  then  Ix-gins  to  evoh-r;  s  gas.  con- 
sisting priueipally  of  ammonia,  but  aho  contaiiiinK  carHon  dioxide: 
after  a  lime  the  residue  solidifies.  The  fnliowtig  reactions  tak« 
|)]ace. 

Two  nioleculfs  of  nrpa  lose  one  moIeciUo  of  ainmouia,  with  pro- 
duction of  liiuret : 


CO 


H,N, 


XjNHrTf)  UN 


\co 


?ai,.CO.XH-CO-NH,  +  NH,. 

BIUMI 


Tills  is  n  crystnllino  sutiBlaiiM'  which  melts  At  1VA*,  and  give«  a 
otiaractcristic  red  caloumtion  when  copper  sglphato  and  cAuatic  |w>taali 
nre  addt-d  to  ita  aqueous  solution. 

On  furtiier  heatlnji,  biuret  unites  with  a  molecule  of  unaltcrcHi 
urea»  with  ciiniioation  of  ammonia,  and  fomiatiou  of  cvanuric 
acid  (847): 

NH 

!H1nh(X>.nr-oo.nh!h!    w  CO 


URE^. 


3*J 


I.ik*  \\w  acid  amides,  when  liealed  with  bases  urea  decomjioseB, 
yielding  carbon  dinxide  and  ammonia. 

Thia  qua*ilit.atit:*  titimation  (if  urea  in  ttrine  U  *n  «l>«Tatioti  of 
ooDfliderable  iraponaiiM  in  pb5^ioIOKical  ctieniiilrj,  and  l«  kITk-IoiI  bj 
differeat  methods.  Bukbem's  pToeOM  drpendftupon  tho  dccooipoftition 
of  urcA  Into  carbon  (lioxidu  and  ammonia,  oa  healing  vilbaoaiD- 
monlacal  solntlca  of  baryU ;  tho  carbon  dtoxido  is  ibos  coDV«ne<]  into 
barium  carbonate,  which  can  be  csillected  and  weighed.  In  Kkofs 
method  tbo  nitifist^n  is  qtianiiiaiivelyBet  free  by  treatment  of  fh*urr-A 
aniutioti  Willi  orii:  oj  cauaUc  poi^sli  and  broiaine  CO«rinan.  Bromlauoft. 
in  yhicli  poiawmim  nyjioftMniltc  ll  pWAcnt ;  ihg  r|Uftiit:ty  of  arw  caa 
be  calcnlatcct  irom  the  volume  of  nitrogen  libcrnicd  Liciim'siilrnllon- 
Toetbod  is  bflsed  upon  the  forranlicn  cf  a  vbii«  prt>eipilate  of  the  com- 
IKMiition200N,H«.HK(SO,).-»Hi[0,  when  mi^rrurlc  utlralo»liilit»nia 
run  Into  a  ditntA  lAlution  of  urea  (of  about  3  per  Mot.  concentration). 
IThen  •mccks  of  iliv  mt-rciiry  Halt  baa  bcpti  iidik-tl.  n  drop  of  ili«  1i<|aid 
bran^lit  into  contnct  with  n  solution  of  todiam  carbonate  );ivc6  a  yellow 
prei'lpltate  of  baaii:  oiltato  of  mercarj'.  Urine  contains  anbstances 
L  which  interfi>re  with  these  molliads  of  calimation  ;  an  account  of  tb« 

I  mode  ijf  pnwpdiini  by  which  ihe  corirct  percenti^  of  ur»a  can  be  aa- 

I  nttaiaed  will  bo  found  In  icxi.bookii  of  physiological  01100118117, 


Polafiaium  cjranale  and  hydrazine  liydralc.  IIiN'NH.  +  H,0,  roaet 
^■^  touelher,  viilh  fonnation  ot  itmicaxbatide,  NHi-CO-NHNlIi.  a  bano 
whioh  melts  at  M*,  and  oombipea  with  aldehydea  and  ketoin-a tiniilmjy 
to  liydroiylaminp: 

R..UjO^n,iN-NlI-C0.NU.-*R.-C:N-NH.00-ira,. 

The  componnda  thua  formed  arc  cidled  semifar(iatone.i :  they  some- 
tiuM  oryBtalliM  w*ll.  and  are  employed  in  tlic  identification  and 
wparation  of  alilehydes  and  ketones. 

SeriTatiTCi  of  Carbamlo  Aotd. 


254.  Carhamic  add,  NH,'C(>"OH,  which  is  the  spmi-amid«  of 
carbonic  acid,  i:*  not  kiiowu  in  the  ftxv  state,  but  only  tut  saHa,  c»tcm, 
and  chloride.  The  ammonium  w/f  U  formed  by  the  uoion  of  diy 
carbon  dioxidv  wi'h  dr)'  anmioiiia: 

/OH  /OHNH, 

CO,  +  xu,  -  C^O    ;  +  Nir,  -  c=o 


\ 


NH, 


Ammaiilum  nrlumai* 


No  ppctfipitrfte  is  formed  wbnti  carbon  dioxide  ia  pansod  iuto  as 


JW 


OKCANIC  CMEMISTttr. 


aahHiao  of  okiuni  chloride,  siiiee  tbr  multing  aiMum 
',  CO        .  is  siJuIjIo  in  vatcr. 

tbe  nits  of  wbsmic  acid  am  hmted  hi  aolatioa,  they 
uhe  np  water,  fonnuiK  raib<jnat». 
Ife  men  oi  enrtamic  arid  art   calird    urrfAano.      They  mrp 
bjr  Ihr  aetiaa  of  ammooia  or  amiskcs  t^Wft  the  cetera  of 
add  or  eUorourhooic  acid . 


-y^OOH. 


*  H  NH,      /XH, 

=  00        +CAOH: 

/OTHtNH,       /NH, 
00  -•00 

Uietlmei  abo  nmiit  from  Uw  aebon  of  alcohol  npoo  isocyaourio 


+  HOCjH,  -  C^ 
NCH,  \XHCH, 

a»  abo  obtained  bj  boiliiig  add  azides   (IM)  witb 


Sae*  the  aiidcs  an  cattly  prvpaml  fram  the  eMTwpoDdlogacida.  and 
the  BTcdMUMS  nadilr  jndid  tbr  rarrBspoadtng  amnm.  tbe  carboxyl- 
gro^  eaa  bf  Um  aMoa  b*  «a«l7  fiptowd  br  the  Kaida>groiip  : 

R-COOa  —  B'OOOCili  —  B-COSHNH. -<  tItx>Xi -^ 
aril  ftMT  Brdiarito 

-.R-5H00OCH,  —  R.5Hv 
tTrrthanri   (fiadl   wHhoitt    deeompoeitian;  ordinary   urcthaQe, 


.  m«hs  at  SI",  and  ts  7ier\-  readily  sotnble  in  vater.   Wben 


•cs  =  4Ca. 


IXRiyATiyES  OF  CARBAMIC  ACID  ANO  THIOUREA.      325 

hoilccl  with  bases,  it  decumpoeea  iato  alcohol,  carbon  dioxide,  snd 
aminoiiia. 

Correeponding  saiphur  dorivatirog  cnti  bo  prepared  \>y  ftnnlogoiiB 
metlKxtit;  rarboii  dlsulphttte  and  alcoholic  ummoDia  yield  (tmtfiurWnm 
Udhiocarbvnatt : 

•NH. 

C8,  +  aun,  =  6> 

This  salt  is  auatablo,  aod  on  troatment  iritb  more  ammoala  readily 
Icses  suIpbuKlUxl  hydrogun,  ioimiti^  mnmuiiium  tkUx^tuxU : 

CS^M'"      +  3NH,  =  C8:N.NH.  +  8(NH.).. 


jiiumoiiluni 
dl  UiltM»  rbamala 


Ainiuouluai 
IlUocjaiiat* 


Primary  amiueaalsoadd  on  t^,  ioa  maDQeranalcgoos  to  ammonia: 

/NUR 

C8,  +  aNH,K  =  US 

\8H  NH.R 

]a  prmenoe  of  roercnrlo  or  ferric  chlorld«,  tlkUKe substituted  drthiocar- 
bainaiM  ftl«>  low  »ulpIiur«Hed  hjdrofpin  readily,  yi«lding  muatard- 
•  ofb  (MB) : 

CB/  -«  C3NR. 

\8H  KH,R 

ThU  reaetloD  ig  osed  as  a  test  fnr  prini&ry  aminM,  Kinaa  tiMw  of  tbo 
inustard>oils  can  be  readily  detected  by  thoir  cbaracterintic  odour. 


Thiourea,  rS(NH,),. 

SU.  AiDmonium  isotJiiiKynvans  yieiilx  Mi'nurm  in  a  maDneraaa]- 
ogoaa  to  tho  formatiou  o£  nrci  frum  amruuiiiuiu  iinxiyaiiiLte  (IU8).  The 
I raosf carnation  of  the  tliio-campoiind  enn  in  ihJK  lii«taii(!ft  bi^i  i-fTt'etad 
by  beating  it  in  tl>6  drj-  slat«,  but  is  no  mor«  otnplctc  llian  that  of 
amnaoniuro  cyanat«,  aince  ibiourea  Is  converttnl  by  b>Mt  into  ammo- 
nium iAOtl>ii>cyAtiAt«.  Alkyl-d«rivatlVM  of  tbiourea  rcaiiU  from  addi- 
tion of  nmnionia  or  amiuw  to  the  mtulard-oits.  Die  reaction  being 
similar  to  th«  formation  of  alicyl-substituted  ureas  from  isocyitaio 
esters  lloe.  eU.). 

ThMc  mode*  of  (ormatiou  prove  tbnt  thocoiislilution  of  (biouroa 
is  aipreued  by  tbe  formiiln  C^(NII|)>,  baing  similar  10  thai  of  urea. 
I)«rtvativa  of  thiourea  Ar«  abo  koovn,  bow<?v«r,  wliicb  indicaio  tbo 


3*6 


ORGANIC  CHEMISTRY. 


/NH,  

eiistence  of  a  tantomenc  form  C— SH    (SSS);  thai,  on  addition  of  an 

alk>l  iodide,  compouiKlsare  obtAiiie<l  in  accurdaucc  willi  (he  equation 
J^^ /    yNH     \ 

cf-sia  +    i|C.n.  =  /  cf  sc.u.  iiir. 

Tho  ftlkyi -group  in  this  compound  is  In  noion  with  xtili^htir;  Tor  it 
(lucuiiipuacs  niib  forniiuloii  of  moraptaii,  and  oa  oxidncioa  yields  * 
■ulphonio  Mid. 

Thiourea  forms  welt-do(incd  crystals,  melting  hi  173'.  and  readily 
solubktt  ill  water,  bul  with  j;reat  difflniilty  in  aloohol.  On  troacmenb 
with  mercuric  oxide,  ii  loses  fii]l|)hurett«d  hydrojcta,  fonsiog  cy^o- 
smide : 

/n|h;        n 

CIS        =  of         +  H^ 

Gaanidine,  CN,Ti,. 

256.  (iuanidine  is  (onneJ  l>y  the  itit^ractiim  of  aiumoaia  and 
ort hot-arboiiic  psUts  or  t-hloropicrici  (161).  This  probably  lakes 
place  tliruugh  atldition  of  fciur  arnitio- groups  to  the  carbon  atom, 
the  conapouiiil  romied  thcti  losing  one  molecule  of  aiiiinouia ; 

/NH, 

OrthoMrbootr-  mler  NNH, 

This  mothoH  of  preparinp  gi]anidin(?  provM  it  to  liavR  the  oormtitu- 
tiniiiLl  fi»niiula  intlicati'ci,  a  view  whirh  (itidHKiipport  In  t\w  Kynthesis 
of  tliiscoiiipoutid  fixHn  animnnia  and  ryaiiariiidiM'fTpL'UHl  by  liealing 
tlie  latter  with  au  alcoholic:  solution  of  ammonium  cliloridc : 


#-^ 


<N 


NH, 


+  NH.Cl 


C=NH    HCL 


Guanidine  is  pcnerally  prnpiirpd  by  healing  ammonium  thiocyanate  ■ 
at  lSO°-lSo°.  whrn  it  i^  obtained  in  the  form  of  gunnidine  thlocya- 
nal«,  thf  rcartion  tukinf;  place  in  stages: 

SCNHNH,  -CS(NH,),  -*  H,N  ON. 

AniinoDlu.111  Uii^cyAOftic     Tblour**  C/uumid* 


GUMNIDINE. 


327 


The  cyanamidc  unites  with  a  molecule  of  the  tinaltcrrd  ammoiiiuni 
thiotyanat* : 

CT        +  NH.HCNS 


^N*H, 


=  (c^nhMhcns. 

liiinaidliia  thioc>'>n»M 


Guanidino  i«  a  cnlourloM,  cr>*8tallino  substaiico,  and  readily 
absorbs  moisture  and  carbon  dioxido  fniin  the  atmnsphon?.  It  is 
a  strong  base,  unlike  urea,  which  has  a  neutral  reaction:  the 
strengthening  of  the  basic  character,  occasioned  by  exchange  of 
carbonyl-nxygcn  for  an  fmido-grnup,  is  worthy  of  notice,  tluani- 
dine  yielda  many  weU-tlefined,  crystalline  salts. 


NUroguanidine,  C~JiH 


,c^ 


NH-NO, 
^  NH 


is  obtBiiifd  bv  the  action  of  fum- 


ing nitric  &e\d  upon  guaniiliit?;  when  th<>  Aolution  in  the  iitrong 
acid  is  pourcKl  into  water,  tlic  slight  solubility  of  the  nitn>fruuni<Unc 
cauiscs  it«  p^■(^ipitatiun.     On  rcduclion,  it  yieldii  aminimiuinidine, 

C=NH  ,  which,  on  boiling  wnth  dilute  acids  or  alkalis,  decom- 

\nh, 

poees  willi  fonnation  of  carbon  dioxide.  ainitKiiila,  and  diamJtle  or 
hydraeine.  H.N'N'H,  (''  Inorcaitic  Chemistry ,"  114).  areaction  which 
provea  the  constitution  of  nitrog:uanidinc  and  amino;:iianiiIine. 

An  important  derivative  of  guanidiue  is  arginine,  CsH„N,0„ 
obtained  from  proteid  compounds.  It  can  be  sj'ntliesized  by  the 
action  of  cyananiide  on  oruithine  (200) : 


^ 


C00H-CII(N11,)-CCH,),-NH,  +  CN,H, 

OrnlUkliiH  Crtsunithi 


"  G00HCHNH,'(CH,)3NH 

NC:NH. 
NH, 

lit  18,  however,  not  quite  certain  whether  tJie  cyanaroide  adds  itself 
\to  the  (u-NH,-group,  as  represeuted  here,  or  to  the  o-NHj-group. 


imiC    ACID    QSOUP. 


tST.  Vrie  aeiH,  C,H,N\0„  derives  its  name  from  its  presence 
aaKuUl  viuHim  in  urino;  it  is  the  oeotral  puint  of  an  important 
(nop  *4  urea  dcrivativps.  It  is  closely  relftt«d  to  the  ureido^citlg 
ami  thr  arid-urtldfa  (urtidei),  wtiicb  are  ainiiu>acidB  aud  acid 
aoMiini,  roDtainiog  the  iirea-rvsk'uc,  XU,'CO'NH — ,  tostead  of  tb 

fVtlowtc  oeid,  CyB^fi^  nmy  be  cited  as  ooe  of  the  acid- 
mtdns;  it  13  obtained  by  the  oxi^lation  of  uric  acid.  "WTiwi  warmed 
W  a  king  time  nith  allcalb.  parabanic  a«id  tak««  up  two  moleoulee 
«f  «mMr.  fomiiti^  urpa  and  oxalic  acid,  a  resctioii  which  proves  U 
to  be  osalflurea  : 

ySn         OHH  * 

ro\  OOOH      ^ 


1 


00 


CX>OH 


H^ 


-NH         OHH 

On  CAralol  tnatoMM  with  aDcalb,  it  takes  up  only  one  m 
r,  jkUiacatotitricaairf; 


CO— NH-CO-\H, 

OOOH 


+  OHH 


Cfi^mfi^  is  M  impartHU 

MiB,  frOMI  VMCS  11  iaOMMMQ  Djr 


itaoa  wMiBilrieaefai;  it 


be  pnfmnA  br  other  metbodL    It  is  to  be  looked  on  as 

vilk  a&afia.  it   takes  np  two 
( cawrtBT, wita pnoBCtiDft n  VM aHd  im  iiiaiii  acad : 

I 

+  ca 

I 

SH, 


CO Sn  +  OHH   COOH 

00   CO       —00 

00 — XH  +  oaa    co  oo 


URIC  MOD  CROUP. 


3=9 


CarboQ  dioxide  and  parabanic  acid  are  produced  by  the  oxidation 
of  alloxan  with  nitric  acid. 

AlIaxAD  is  conveH«I  by  rmlaotion  irtln  nllnmntinf,  tiiw  n-nction 
be!ii|i:  analogous  to  tlio  rormation  of  pinitcoiio  frou  uOTt^aQ  (1&0); 
alloxanitDfl  has  thererora  tbe  Btruotura 


^NHCO     AM  HOv       CO-NH 
NHCO 


CO 
\ 


00.  NH 


Alloxfti)tin«  Is  also  (orincd  direolly  from  uric  *«ld  by  ev&poniting  it  to 
dryness  with  illlule  tiliHc  Add.  When  trc*I«d  irith  aniinflnia,  it  forma 
«  purpIO'Tcd  dy«,  mu^f^riii.  the  nmrnonium  salt  of  purpuric  acid; 
to  this  acid  is  assigiiml  thv  conslittition 

/•MI- 00    NIK      CQ.NH 
CO         ^C V         ^00. 


\ 


NHCO 


00- NU 


This  romutUon  of  murnide  is  omplojod  as  a  ttst  far  urir  acid 
AUoxantine  U  only  soluble  with  consi<)i>rab'lo  difficulty  in  cold  waier, 
and  KJvw  a  fine  lilac  colour  wiilt  liarvta-vrmcr. 

Allanloaie  is  a  dfinoinpiiHitinii-ppnduPt  of  lirir  ncid,  a  fact  which 
has  an  important  bearing  on  the  constitution  of  this  comimiind, 
from  which  it  residts  on  oxidation  with  pntaiviiiini  ix-rniangstiate. 
It  has  the  atruotuie 


/NH-CH— XH-CO-X^ 


CO        I 
NHCO 


All*ntalii« 

siocc  it  can  be  obtained  a>'nthetlcall.v  by  hcBtiiig  glyoxylio  acid 
with  urea: 

H 


/NHg__H0|-C—|0H_£^ UN  CO-NH, 

CO  +  I  nwa 

\NH!H      HO|-CO 
Cra*        OljDxjllc  add 


/NH-CB^NH- CO-NH, 

-»  CO        I 
^NH-CO 


A]UBtobi« 


lacANBT,  ^aemsTiFf 


-  -i 

TSt^rtoc  ■■rrn.  lie-    '"'     *— '    ''  "dev 


T3— : . 

I'  „ 


•'        =!r.-g: 
TS.—- 


?T- 


VMC  ACID  GROUP. 


33' 


vhieli,  Ilka  the  anainm,   julrls    on  one  tD»lneiil«  of  IsoejuDlfl  ack] 
when  brought  into  contact  with  poUusium  cynnate,  rormiii; 
NH— CO 


io    i«(     N». 


NH— <:iO  HlUS 
This  BubetADM  is  pK"tit--uTk  iieid,  aud  only  differs  from  iirio  acid 
ill  containing  tliu  duiuenu  of  luioiher  iiink-cule  of  wautr,  wliidi,  by 
hoihag  will)  n  lurgo  esci^sa  of  hydrochloric  acid  of  20  per  c«Rt. 
stri;ii);Cli,  can  be  split  off  in  ttie  maiiuor  iiidicaCixl  in  Llm  fwrcuulai  this 
trcalmvnt  yi«lds  a  subsunco  wiib  tlie  cotutitntion  assigaed  to  uric 
acU,  and  identical  with  this  compoiind. 

Uric  acid  dissolves  with  great  dilficulfcy  in  water,  but  is  soluble 
in  coiitt-ntrated  eulphuric  acid,  from  which  solution  it  is  procipitatett 
by  addition  of  wat«r.  It  forms  two  series  of  salts,  by  exchange  of 
ono  or  two  h^i^tgon  atotnii  re.speciively  for  metals.  Neutral 
sodium  urate,  CiHpl,<.JjNiiy+  HjO,  is*  mnrli  more  readily  .loliibte  in 
water  than  acid  sodium  urate,  2(^H,N,0,Xa  +  H^O.  The  neutral 
lithium  mit  is  mfulcratcly  noliihle  in  water. 

L'ric  arid  is  prrscnt  in  urinp,  and  is  the  principal  constJtnent  of 
theexcrenicntof  binU,  rcpti]eH,an<lHer[)ent«;  it.  can  tic  conveniently 
prepared  frotn  scrpcnt-cxcrement.  In  certain  patliologicikl  di^iusos 
of  the  human  organism,  such  as  gout,  uric  acid  i*i  deposited  in  the 
joints  to  the  form  of  sparingly  soluble  acid  salts.  Un  account 
of  the  solubility  of  lithium  urate,  lilhia-water  is  prescribed  as  a 
remedy. 

868.  A  considerable  number  of  compounds,  containing  the  same 
carbon-nncleus  as  uric  acid,  occur  in  nature,  partly  in  the  animal, 
and  partly  in  the  vegetable,  kingdom.  To  tlie  ff>rmer  Ijclong  hy- 
jtoxanlhine,  C^}i^S^O;  xanthine,  C^H,X^Oj;  and  grainijie,  C^H^ti^O; 
to  llie  latter  belong  the  vL-getable  buKeu  tlu^olirominf ,  CjH,N\0, :  and 
cajfrint:,  C\H,^\\()j.  In  order  to  assign  a  rational  noincucUitun!  to 
these  suljotmiiM-a  and  other  membere  of  the  same  group.  Kmii. 
FtscHEB  n^ganls  them  an  diTivnlive.s  of  purine  {p.  3S3),  whose 
C-atoms  an<i  N-atonis  are  ntinibored  us  indicated  in  the  formula 


nC'  'C.'NH 


333 


ORG^NtC  OiEMfSTRY. 


\tiiilhiiK',  th(.<«)bn>niine,  and  caffeine  have  the  following  Ktmctura] 
furinubB  and  mtimial  u^ra: 

NH 00 


.  y     Nil— CX)        V" 

"^        CO     C— NHv 

tj 


I.     !i       ^: 


CO 


C-N(CH, 

J               I' 
N(f.:ll,)-C N 

DliiietbrlnuitlilDe,  (limtmiailiia,  or 


-H; 


N(CH,)-CO 

CO  C-X(CH)r. 

[  II  Vh. 

N(CtI,)— C— 


Trlnufib]>lxiiii(liiiiv.  c?K)Tt-iiie. 
or  l:l:T.l(lRicllifl^:S- 

ThflobrcoDine  and  caSoIne  n>«iitt  from  Llie  iritj^CuiioD  of  nethyl- 
BTonpcv  intn  xniilhiiio. 

Xtuithtne,  CiHtN.O,,  is  pre.ient  tn  mII  Iho  lii«iins  of  the  tiunmii 
body.  Il  is  a  uuluurluBs  jxxviJvr,  nulubb  Willi  tliWculty  in  wnti-r,  nod 
posvnasing  a  weak  Ijahio  olmractrr.  <.)n  oxidation,  it  yieliU  atloutn 
nod  urea. 

Thmibromine,  C.ll.X.Oi,  oxiatB  in  cocoa,  ntid  is  prepared  from  tbU 
in>urr«.  It.  ia  i>nlj-  i:<,IiK)itly  aoliibleiii  wawr,  and  isconTerted  l>y  oxida- 
tion itilo  ■mottotiirthy I iilloMin  unci  timttomflhjftmta. 

Onfftlnevtthrhu,  ('•IlnNiOi,  ia  o.  coiistLluent  of  coffee  and  tea.  It 
erystalltsHH  witti  utie  uiulcuuLo  of  vMer  in  long,  silky  iieedloe,  and  ia 
moderately  tmlnble  in  water.  It  in  generally  prepared  from  toa-duac. 
On  cnrofut  oxidation  it  yields  dUnethytaliojan  and  tnonomtihyhirta. 

Tbc  pvsition  of  the  mvUiyl-|rruui»  in  ihcobioiuiiie  aud  caffeine  ia 
provoil  by  llio  formation  of  thww  oildatlon-proiiucU. 

Them  ia  an  ovidi-nf  rcBcniljIaiico  belwopii  the  constilutioD  of 
urir  Bi!i(l  aiiil  ihiMu  of  xanthine,  llieubroniine,  and  c«iTeme: 

NH-CO  NH-CO 

00     C— J 


-NH 


Xnh/^ 


CO    c— Nir 

i_-   I 


iCH. 


NH-C— NH^  NH-C- — ^N< 

Vt\C  acid  ZanUiino 

lliefle  formuIsB  indieate  the  possibility  nf  obtaining  xanthine  by 
the  retiuclion  of  uric  at-id,  and  up  to  Ihc  year  1897  numerous 
un»ucccssful  attempts  were  made  lo  prcpure  it  by  this  method,  • 


PURINE  DBRiyMTiyES. 


333 


reaction  ultinuitely  effected  by  Emii-  Fiscber  in  that  year.  He 
lias  diseoverod  several  methods  of  eonvprting  uric  acid  into  the 
three  cwmpoimds  ineiuiuncd  above,  iiu-luding  oue  by  wliich  the 
manufacture  of  the  tluTainMitically  imporlant  lawes,  theobromine 
and  eaffeViie,  seems  to  be  pusstble. 

To  convert  uric  acid  'mXx*  xanthine,  it  in  first  treated  wilb  pho*- 
phorus  oxychloride,  yielding  S-<Kcy-2:G-dichloropvtTin<;  this,  ou 
further  earefiil  treatment  with  the  same  rcageut,  is  eonverted  into 
2 :6  :S-trCchioropurine  : 


C— NHv 

N— C N"^ 

•t:  d^  KTrEchloniiiurtD* 


At  0^  and  in  presence  of  hydriodie  acid  and  phosphonium  iodide 
this  trichluropurinv  chajiges  inludi-iadopwrine: 

C;HN,CIj  +  4H1  =  C^HjN.lj  +  3HCI  +  21. 

Rvdudioii  of  llitf  iHjueuus  siilutiun  of  di-iodoiiunno  with  zinc-dust 
ylctldK  jmrtnt.  a  wblio  or/KUilljne  stibBtAnce,  meliitig  at  ilt'-21T, 
aud  rcrj-  n-nd]!y  eolublo  in  water.  Il  is  a  weak  bi)«e,  Binco  It  does 
HOI  liim  red  litmuii  blue. 


The  Cl-atoui  H  iii  trichlnropimnc  is  very  stable  towards  alkalis, 
while  the  Cl-atomf<  2  and  6  are  dioplaaed  with  comparative  ease; 
when  trichloropurinp  iH  tro&tmlwith  siidiiim  ethoxide,  the  Cl-atoms 
2  and  6  are  exehangcd  for  etlioxyl-groupB.  On  lirating  the  eom- 
pnund  thuH  obtainwl  with  &jgi^0ion  of  hydriodic  acid,  the  ethyl- 
gniupe  are  n-placi-d  Uy  hydnjRen,  the  Cl-atom  8  being  simulta- 
neously exclmnK<^  for  an  H*atoni,  with  formfttion  of  xuntliine: 


N^=COC,H, 
CH,0-C    C— NH 

li> 

a:«-Dle(li«Q  '  <-iJ( 


I      I 
-HOC    C— NH 

II  > 

tt—C—S 

XAUlhlii*  <lkut«inerii;  form) 


NH— CO 
-CJO 


C— NH 


XH 


-N 


JUnllilM 


334  ORGANIC  CHEMISTRY. 

WTien2:&4icthoKy-8-<3Mon)ii}irine  in  heatwl  wth  hydrochbrio 
acid,  only  ihn  ptiiyl-groiips  arc  replaced  by  hydrogen,  nith  produe- 
tioa  of  a  compound  of  ihc  formula 

HN— CO 


coc— : 


NH 


HN-0-; 


On  methylaling  this  siibfitanc&,  its  three  H-atoms  are  exchanged 
for  nKthyI-g^o^lp«,  yielding  ehlorocajfe'in^,  n-hioh  can  be  cnnvcrlwl 
by  nascent  hydnigvn  into  calTeTtic.  TtiiH  is,  tliercfore,  a  niethiKl  i>f 
pn>panng  GBfTc'iiie  from  iirlc  acid. 

]£wL  FiscHEK  has  disrovcrwl  a  very  characteristic  and  Mmple 
lucxlc  of  effecting  this  methyl  at  ion — agitating  an  alkaline.  a(]iirou$ 
Bolution  of  uric  aci<I  with  methyl  iodide,  whereby  the  four  hydm- 
gon  atoms  arc  readily  replaced  by  methyl-groups,  with  formation 
of  a  tctpamothyluric  acid.  On  treating  this  with  phosphonis  oxy- 
chloride,  POCl,.  chlorocaffGYno  ie  formed  in  accordance  with  Ihe 
equation 

3C,N.0,(CM.),  +  POtn,  =  30,Np,(CTIO/1  +  PO(OCH,)„ 

and  cao  be  converted  by  nascent  hydrogen  into  caffeine. 

Electro-redaDtioa  of  Parine  Deriraf ivei. 

Tapel  has  stated  thai  eaifeme,  xanthine,  uric  acid,  and  other 
ninilar  comjMmniU,  nnlueiblc  with  difTieitlty  by  the  nrdinan*  nioth- 
mls,  readily  add  on  hydrogen  evolved  by  plnrtroJ^'sis.  I'"or  this 
puqKise  the  comiMiumls  are  dJj«o!vei!  intiiilphurieaeid,  the8lren(»th 
n(  whieh  is  varied  l^i  suit  Ifie  pnrtieular  eompmind,  anil  lies  iK-twi-OD 
50  and  75  per  cent.  This  solution  i:i  contained  in  a  porwif>  cell,  and 
a  lead  cathode  immersed  in  it.  This  cell  is  placed  in  stiJ])hiiric  aeid 
of  20  to  60  (jcr  cent,  slreuf^th,  which  cunlains  the  anode,  'llie 
hydntgen  evolved  at  the  cathode  hy  tlie  current  readily  effects  the 
n^hirtioii  of  the  above-mentionctl  cwmpounds. 

Xanthine  ami  Ms  lioinologuies  take  up  four  atoms  of  hydr 
booomiug  transformed  into  deoxtfdmtxitivts: 

CbH„0,N.  +  4H  =  CJI„ON.  +  fl,0. 


ntscrno-REDucnoN  of  purine  oERiyATiyES.        ns 

TTicsc  uru  stronger  bases  llioii  tlic-origiiial  substances,  which  have 
very  weakly  baac  propcrtica. 

Thp  r(>(hiction  of  nrir  nr.ic!  is  somewhat  renitirkable,  requiriug 
ax  hydrogen  atoms,  and  yielding  purono: 

C,H,(>,N.  +  SH  =  CjH.OjX.  +  H.O. 

It  is  the  carlwn  atom  fj  whose  oxygen  atom  is  replaced  by  hydrogon  ; 
At  the  same  limo,  two  hydrogen  atoms  an*  ad{l[>d  at  the  double  Unk- 
ing ni  the  urio  flckl  moleniile: 

'NH— «C0  NH— CH, 

KO     »C>-'NH\„^      CO     CH— NH^ 

/"CO—  >co. 

VrlcMicl  niniiie 

This  structure  Is  pnivfld  l>y  the  fact  that  punnie  yinlils  two  mole- 
eiiles  of  COj  on  hpalinp;  with  baryta-water,  kh  that  it  must  rtmtain 
two  nnaltervil  iirpa-residiipj*.  which  nccpNiutatcit  thp  prpspnrr  of  the 
carbtmyl-Krciups  3  and  S.  Thr  carlionyl-grnui)  6  can  be  proved  to 
be  the  one  n'duc^ed  in  xanthine  and  its  homnlofoics- 

Ptironi^  \ii  neither  a  ba^ie  ntir  an  acid,  and  is  nnt  attacked  by 
oxidizinp-agcntj;.  When  wanned  with  a  10  per  cent,  solution  of 
caiutie  soUa,  it  m  Iraiu^onneU  mtu  iio^irmu:,  whieh  has  acidie  prop- 
ertiea,  and  \%  readily  oxidized. 

Tlie  app]icaii(m  of  ihf  electro-i-eduction  mi-thod  was  at  first 
attoDiIed  by  many  diflicultics,  groaiiy  varying  yields  bcuig  obtained, 
even  when  tht^  process  wojt  appatviitly  earned  out  in  exactly  the 
some  way.  T.vftl  hxis  both  dtsi-overed  the  cause  of  this  anomaly, 
and  indieaU^d  a  method  by  which  tht<  prriceBH  can  be  kept  under 
coiitml.  His  investigations  are  of  general  interest,  and  are  worth 
cle«cribiiig  m  some  detail. 

In  onk-r  to  have  a  method  of  obwrving  the  course  of  the  reduc- 
tion jjrucCHS,  Tafel  closed  the  porous  cell  with  a  fitopjier,  through 
which  the  cathode  and  a  dehvcrj-  tube  for  the  g;as  were  introduce*!, 
cart-  beinK  taken  to  make  the  connections  air-tif^ht.  A  second 
apparatus,  exactly  similar  lo  that  used  for  the  reduction,  but  con- 
taining aeid  alone,  without  the  purine  derivative,  was  introduced 
into  tlie  same  circuit.  Periodieally,  tlie  gas  from  both  was  collected 
at  the  same  time  during  a  apace  of  one  minute.     The  difference  be- 


336 


ORGANIC  CHEMISTRY. 


tween  these  quantities  ar  gu  is  a  <Iirt»:t  mE'&sure  of  the  coursn  of 
tJie  reduction  durini;  thai  iiiinuic,  since  it  iiidicalos  the  qumitiiy  uf 
hydrogrn  uwcl  fi)r  llic  ndtictioii. 

When  this  quantity  is  rcpreaeuted  ffrapliieally,  the  abscissiD 
standinf;  for  the  time  which  has  elapsed  since  the  bepinnJnp  of  t  Ik 
experiment,  and  the  ordinales  for  the  ciiiantity  of  hydrogen  iise<i 
for  the  rwhiclittn,  tlie  normal  course  uf  ihe  latt«?r  must  Iw  indicated 
by  Fig,  70,  since  the  quantity  cf  hydroRca  absorbed  in  the  unit  of 
tJme  mu»t  diminiKh  in  the  same  proportion  as  the  quantity  of  unre- 
duced purine  derivative. 

Tapel  has,  however,  observed  that  the  addition  of  traces  of  a 
platinum  or  eopper  salt,  as  well  as  tif  rertatn  iilher  sails,  vory 
quickly  redure-s  the  quantity  of  hyJrogeji  al»sorbe?d  to  nparly  zero, 
the  grapliic  n^prescntatioii  in  this  case  for  the  additi(in  (if  0 '  04  niilli- 


TtHE    m    VIHVTE* 


Fio.  70.— Normal  Rkdoctiok 

CUKVK. 


Fio.  71— Ahnosmal  Rbddctioh 

CURTK. 

grammes  of  platinum  for  each  100  square  centimetres  of  cathode- 
surface  is  shown  in  Fig.  71.  This  indicates  that  the  slightest  con- 
tamination of  ihe  load  of  tho  eathotJe  by  certain  othei  melals  is 
sufficient  to  almost  wholly  stop  the  plectro-reduction. 

The  followin^t  considerations  afford  an  insight  into  the  cause  of 
this  phrnoinennn.  Hydrogen  is  only  evolved  hv  the  passage  of  an 
electric  current  through  dilute  sulphuric  acid  when  the  difference 
of  potential  of  the  electrodes  exceeds  a  certain  value.  This  is  a 
tnininium  when  plalimini  eiectrodes  are  used,  and  very  nearlv 
coinciiles  with  the  potcnlial  difference  to  be  cxiR'cted  on  thwireticat 
grounds  for  a  reversible  hydro)i;en-sulphurie-aeid-o.xvgpn-element. 

"WHien  the  cathode  is  nia<le  of  other  metals.  Lbc  clifiference  of 
potential  is  crcaicr  before  the  evolution  of  hydrogen ;  for  this  a 
tupertengitm  (German.  Crfrmipnnnwng)  is  necessary.  This  has  a  very- 
large  value  for  lead,  but  as  soon  ns  the  least  trace  of  platinum  or 


b 


ELECTRO-REDUCTION  OF  PURINE  DERjyATiyES.  337 

of  certain  other  metals  is  brought  into  contact  with  the  surface  of  the 
lead  cathode,  the  supertension  disappears,  and  with  it  the  power 
possessed  by  the  evolving  hydrogen  of  reducing  purine  derivatives. 

This  has  a  deeper  lying  cause.  The  diCference  of  potential 
regulates  the  energy  with  which  the  discharged  ions  can  react,  for 
the  pressure  under  which  a  discharged  ion  leaves  the  solution 
depends  only  upon  the  difference  of  potential.  Nehnst  states  that 
by  varying  the  difference  of  potential  it  is  possible  to  obtain  pres- 
sures from  the  smallest  fraction  of  an  atmosphere  up  to  many 
millions  of  atmospheres.  Heiice,  reductions  which  are  unattain- 
ble  by  other  methods  and  without  supertension  are  possible  at 
cathodes  where  it  exists. 


SECOND  PART. 

AROMATIC  C()Ml*orXDS,  XSD  SUBSTANCES 
RELATED  TO  THEM. 


IHTBODOCXION. 


269.  With  but  fow  pxwptinns,  the  ccinipt>un(Js  described  in  the: 
first  part  of  this  lunik  eoritaiii  an  open  rhaiti.  As  examples  of  these 
exceptions,  closTd-chain  i;»iiipi)un(l!tstirh  as  the  lactones,  the  anhy- 
dritles  nf  ch'liasic  iirids,  and  Wiv.  urit;  at-id  groiip  may  bo  nicntioncd. 
The  cioiM-d  chain  «f  tltrsc  ('oinpoiiiids  is  very  ri-adiiy  otx-ned,  and  the 
dose  relationship  of  (heir  methods  of  forniation  and  proporlies 
with  tliosc  of  the  open-ehain  drrivativps,  makes  it  dosirable  that 
they  should  be  inchide«l  in  n  deseriplion  nf  the  fatty  compounds. 

There  exists,  liowever,  a  large  number  of  substances  coniaiiiing 
dosed  chains  of  great  stability  towards  every  kind  of  chciiiiral 
reagent,  and  whoae  properties  differ  in  ntany  iinpurtjiiit  n-^iH-ets 
from  those  of  the  fatty  compounde.  Chief  among  these  is  benzene, 
CftH,,  with  its  derivatives.  The  molecule  of  heniene  rnntain?  & 
clnsnd  chain  of  six  eartxm  aloinit  (263) ;  tliiH  siilislniiee  »n<l  Us  deriV' 
atives  comilitiite  the  gniup  of  aromatic  compounds.  Renzcne  can 
take  lip  six  hydrogen  atoiris.  with  formation  of  hejrameth/lrttr,  r«ll,j, 
a  rompoitnd  whirh  also  contains  a  closed  riLrboii  ehaJn  of  six  atoms, 
but  approximat c»  in  pruperlics  lo  the  fatty  much  mure  thaittn  the 
aroraaiic  group.  Compounds  of  the  formula  C„Hm  are  also  known, 
containing  a  closed  chain  of  four  or  five  carbon  atoms,  and  they,  too 
liave  similar  properties  to  tho  fatty  eompounds. 

The  closed  chain,  ring,  or  nuclfus^  in  benzene  and  its  deriva- 
tives, and  in  the  closed-chain  hydrocarbons  C„Uj„,  consists  of  the 
atoms  of  a  mngle  element,  carbon.  Compounds  of  this  kind  are 
called  komocycHc. 


THE  AROMATIC  COMPOUNDS.  339 

Closed  chains  containing  atoms  of  two  or  more  elements  are 
also  known :  pyridine,  CbH,N,  and  its  derivatives,  have  a  ring  con- 
taining five  C-atoms  and  one  N-atom;  furfuran,  C4H4O,  four 
C-atoms  and  one  O-atom ;  pyrrole,  C,HjN,  four  C-atoms  and  one 
N-atom;  Ihiopken,  C,H4S,  four  C-atoms  and  one  S-atom;  pyrazole, 
CjH^Nj,  three  C-atoms  and  two  N-atoms;  and  numerous  other 
examples  might  be  cited.  Such  substances  arc  classed  together  as 
hetiTocydic  compounds. 

There  exists  another  class  of  compounds  containing  condensed 
rings,  or  two  closed  chains  with  atoms  common  to  each.  A  type 
of  those  is  naphthalene,  C|,Hg,  containing  two  benzene-nuciei.  Two 
dissimilar  rings  can  also  have  atoms  in  common,  as  in  guinohne, 
CjHyN,  which  contains  a  benzene-nucleus  and  a  pyridine-nudeus. 

Since  numerous  derivatives  of  all  these  compounds  are  known, 
the  scope  of  this — the  aromatic — division  of  organic  chemistry  is 
much  more  extended  than  that  of  the  fatty  series  The  descrip- 
tion of  the  aromatic  group  is,  however,  greatly  simplified  by  the 
fact  that  in  it  the  properties  of  alcohols,  aldehydes,  acids,  etc., 
already  described  for  the  fatty  compounds,  are  again  met  with. 

The  most  important  of  the  closed-chain  compounds  are  benzene 
and  its  derivatives,  and  these  will  be  described  after  a  brief  con- 
sideration of  the  compounds  of  the  formula  CdH„,  containing  rings 
of  three,  four,  or  five  carbon  atoms. 


POLYMBTHTLENE   DEEIVATIVE8. 


I.   TBIMETHYLEBE  OEEIVATITES. 

CB.V. 
SOO.   Trtrntlhylcitu,  CiU*  =   I       >CIli.  is  obtiUiied  t^  the  action 

CII.'^ 

of  Boditim  on  trimetliykiie  bromide,  CH,Br-CII,-CH,Br  (IM).  It 
b  a  Kaa,  wbich  liquefies  at  a  I^^eHfl(l^e  of  from  fisa  Xo  kIx  niRi(M(ili«r«. 
and  iii  not  identical  with  propylene,  CHt:CII-Clli,  aiiu'v  witli  liroinino 
it  forms  an  luKliLJuti-iinHluct  only  very  »lon1y  under  IIjo  iuHneuce  of 
snnlight,  yielding  liinifttijlono  bromido.  This  r^nclion,  togotbor vrith 
its  aynthesia,  proves  it  lo  hare  the  wbovc  conatiimlon. 

DerjvatiTes  of  trini«tliy]etie  aro  obtained  by  the  action  of  cihylecM 
tironiide  on  aodiaoiBlonlccscsr: 


CM, 


Br- 
Br 


+  Nft. 


C(OOO0iH,),  =       I  XCCOOCHO.  +  SNaBr. 


By  Kaponifloation  of  this  eater  a  dibanic  acid  is  obtainw]  vhlch  uplits 
off  CO,  when  heated,  with  formAtion  of  tnmethi/laiscarbarj/lic  acid  : 

I^CU-COOH. 
CHi 

n.  TETRAKBTHTLEIIE   DEBITATIVEg. 

961.  TctrnmcthylBii^  iiself  Is  iiol  kuuwu.  but  it«  deriratlvca  iiro 
obtaicLud  iLtiiilugously  in  )rinii>lhylvnw  compouailii.  Wlieii  sodiomn- 
Ionic  ester  reacln  with  trimfithylono  bromidv,  the  6»t«r  of  A  ti^ra- 
tntt/tfflenmiicarboj:y[ic  acid  is  (ormm!  r 


CH, 

on. 

OH, 


Hr 


+    N*, 


Br 


CH. 


qCOOe.H.),  =  VHt  C!(CO0C,H.).  + 


9NaBr. 


CI!, 


m.  PEHTAMETHTLENE  DZRIV&TITES. 
28S.   PontatUKthyloQfl   il^rivudvcs    can   Ito  obtalnwl  by  a  similar 
motbod,  the  Action  of  tftmmotbyloiiQbrumido  oii  sodiumalonic  ester. 


POt.YMF.THYLENE  DERIb'ATtyES. 


341 


When  ihocjilciiini  salt  «t  adipio  aci<I  is  aiibmiltcd  to  drydisUlIa- 
tioD,  a  keto>dei'ivxlive  at  pentamelhylvuiji  is  formed  : 


CH,.CH,.CO.|0\ 


OH.-Cll,.  [CO  O 
C&lclum  ofUpAio 


>Cji     =:    CaCX).  + 


y 


oHiCHis^ 


CO. 


OH. -OH/ 

KetU'|ient«> 
nwthfk'ne 

Tlie  Structure  of  this  eoinpound  U  prov«d  bj-  iU  oxiditlion  to  glaUltio 

acid : 

CH,CH,v  CH.OH.OOOH 


CH.CH, 


/ 


CO 


CH,-( 


-COOH 
IJIuInrfD  aoIJ 

Pmtauutftjflttit  is  obtained  by  (b«  rodiiDtion  of  ibia  ktto-derirative, 
tliv  carbon )'l* group  taking  up  two  Il-atomii,  wilb  fnrtnnllanof  a  C'HOH- 
group.  By  trv>Hliiieiit  with  hjdriodic  ncitl,  bydivzfl  is  fint  rvplac«d 
bj  iodiae,  and  llti»lly  hy  IiyiIro);iMi : 

Cn,.CH^  (.'H,CH,> 


I 
CH..CH, 


/ 


CO 


I  '^CHOH 

cn.-CH,^ 


—    I 


CM,  CH, 


CU.CU, 


CHI     —      I 


CH.CU.x 


CU,  CU.' 


PentaiB«th7tea«  is  »  coltmrlns  Ii<]tiid  boiling  At  50°. 

Afcording  t.o  the  "tonsion  thcorj* "  of  Baever  (129),  the  fonna- 
lion  of  a  I  rimethyleiie-ring  and  a  totraincttiylpui'-ring  necessitated 
an  altiTation  in  the  dirortion  of  the  affinitieg,  since  only  in  a 
chain  «»f  five  earbmi  a|nm.<4  arr  the  »niiiili<'.s  sufficiently  near  to 
one  anothpr  to  fomi  a  ring  without  Mng  hcnt  from  their  direetion 
(169).  It  followa  frntii  ti)i»  that  the  pent«tnethyleiie>ritig  must  be 
v«r>'  stable,  while  the  tctrainethylcue-rin^.  and  still  more  the  tri- 
roothyleiK'-riiijK,  liave  a  t^iiilency  to  njjen,  so  as  to  bring  back  the 
boiHls  to  their  original  dir(.>etioii.  These  conclusions  arc  fully  s%x\t- 
|Mirtei]  by  I'xpcritncnl.  Triniethylene  forms  an  addition-produet 
with  brouiini-  (:260).and  willi  other  substaneea,  such  as  liydrioJic 
aci(],  whereby  the  closed  chain  is  opened.  The  reaction  does  not 
take  place  so  readily  as  the  addition  of  brnmine  to  substances  con- 
tailUOg  a  double  bond,  mich  as  propylene,  because  the  iMmda  of  such 
onnipounds  are  more  alteiwl  in  direction,  and  are  thi^rehirv  niore 
easily  broken,  than  tbos<*  n(  the  clawd  rhain  of  triniethylt-ne.  Penta- 
methyleno  does  not  yirld  an  .iddititui-prodiict  with  bniniinc,  and 
(Uspla>'s  the  same  stalnlity  towards  nilrio  acid  and  sulplmrit;  arid 
a»  a  saluralL-d  hydrocarbon;  it  thus  shows  no  tendency  to  opening 
of  the  ring. 


342  ORGANIC  CHEMISTRY. 

A  consideration  of  the  great  resemblance  between  the  proper- 
ties of  pentamethylene  and  of  the  saturated  open-chain  hydro- 
carbons leads  to  the  important  conclusion  that  the  formation  of  a 
ring  does  not  in  itself  make  any  aitcraiion  in  the  properties  of  com- 
pounds (378). 

Analogous  to  the  production  of  ketopentamethylene  by  the  dry 
distillation  of  calcium  adipate  (p.  3411  is  that  of  ketopolymethylene 
derivatives  from  the  calcium  salts  of  the  higher  saturated  dibasic 
fatty  acids;  thus,  calcium  pimelate,  CyHioOiCa,  yields  ketohexametkyl- 
ene,  and  calcium  suberate,  CgH^O^Ca,  yields  ketoheptametkylene 
or  siAerone.  The  yield  of  the  diflferent  homologues  obtained  com- 
pletely agrees  with  Baeyer's  theory;  for  the  closed-«hain  com- 
pound with  five  C-atoms  it  is  theoretical,  and  diminishes  rapidly 
for  its  higher  homologues  with  increase  in  the  nimiber  of  Oatoms, 
a  proof  of  the  instability  of  the  rings  containing  six,  seven,  or  more 
carbon  atoms,  of  which  further  evidence  is  afforded  by-the  conver- 
sion of  hexamethylene  compounds  and  aromatic  derivatives  into 
pentamethylene  compounds  by  hydriodic  acid  at  a  high  temper- 
ature. 

Hexamethylene  lierii'ativea  are  described  later  (270), 


t" 


S63.  Certain  siibstfliipf>3  fnund  in  the  vegetable  kingdom  lire 
charact*irizcrl  by  thi*  pdsstwsion  of  an  a^iwablo  aroma;  siiph  are 
oil  oj  biUtr  almon^x,  oil  oj  rarmwati,  nil  of  cumin,  Utlsam  n/  Tolu., 
gum-benzoin,  inniV/n,  etc.  These  vp-gctabloprodiK^ta  consist  prin- 
ciiwlly  of  siibstannM  of  sonicwiiat  similar  nharnctor,  which  differ 
from  the  fatty  compounds  iti  ocintoiiimg  much  less  hydrogen  in 
prop<Jrti<tn  to  thff  other  ek'nient^i:  thus,  cj/mene,  C,oH„.  is  obtained 
fminnl)  of  t-arraway ;  lolfifTip,Cj.]lt,  from  bal^tam  of  Tolu ;  and  Aenzote 
acifi,  Cjll,0,,  from  gum-benxoin.  The  saturated  faity  coinpounda 
with  the  same  number  of  C-atoma  have  the  formulie  C,aHj„  C;H,^ 
and  C,H„0„  rpBpectively. 

Before  the  nature  of  the  so-called  aronuitit:  compounds  had  been 
closely  investigated,  atid  on  atcouiit  of  their  ext<»mal  similarity,  it 
v!Bn  cuHtomary  to  reganl  llit'iii  as  niemlwrs  of  a  fcingle  group,  jnst 
as  ordinary  butter  and  "buUvr  of  aiiliiiiuny."  SbCI^  were  elasied 
togcthrr  txTftuac  of  tiicir  similarity  in  eonsislency.  This  method 
of  clufttificiition  is  still  adopted  fur  eoni|»iund»  with  analoeovis 
proptTl  ic»,  but  of  imperfectly  understood  conislitution,  such  as  the 
bitter  principles,  vegetable  alkaloids,  and  many  vegetable  dyes. 

A  closer  study  of  the  aminalip  eonijwtunds  ha«  Khonni  tlmt  the 
old  and  somewhat  arbitrary  cliiR^ification  acrording  to  exlcmal 
resemblance  is  well  foundeil,  sinre  all  these  siibstanr^s  may  be 
looked  upon  as  derivatives  of  one  hydroearbon,  hcmcne.,  0,11,.  just 
asthefatty  compfjuiuisari-  to  be  rrgardi-d  a«  <ierived  fmm  nirthane, 
CHi.  Thus,  on  oxidation,  toluene  yields  bcnsoi'c  acid,  whose  cal- 
cium 8alt  is  converted  into  benzene  by  distillation  with  lime.  Tho 
cUbasie  terephtlifilic  acid,  C,11,0«,  Is  formed  by  the  oxidation  of 
cymene.  and  can  be  similarly  transformed  into  benzene. 

Tbe  discoi-ery  of  this  relation  by  Kekui.!;  brought  into  promi- 
nence the  question  of  the  constitution  of  benaene,  the  basis  of  all  the 
aromatic  compounds.    When  its  fonnula,  C«H«,  ia  compared  with 

343 


344 


ORGANIC  CHBMlSTfiY. 


that  of  the  sBttirated  parafHn  contBiniiig  six  CVatoniB,  hexane, 
C,H,„  it  is  swn  that  it  contains  a  much  siiislter  pcreeiita^  of  hydro* 
gen,  Bitice  thcif  are  eight  I  I-atonie  fewer  in  its  molecule.  It  might 
be  enggcstecl  that  benzene,  like  other  hytbwjirboiis  pf>or  in  hydrc^eo, 
8uch  asCoH,,  aiidC,H,o,c^»ntain8  multiple  carWn  boiiUs.but  the  i>rui>- 
ertire  of  bt^nzetie  di»  nut  admit  u!  Ihis  asKUinptinn.  Com[i«unds  c<m- 
tttuung  a  miUliplo  earboii  bond  readily  ftinn  ad<Ution-pnHluct»  with 
thi-  hiiloKi-ns,  ar^  vitv  sensitive  U>  oxidizing-agents,  and  easily  n-acl 
ttitli  Baktbr's  rfagcnt.  (123):  U^hw-iil-  lacks  tlicse  proptTlics.  It 
yi<'lda  lialoRen  mldition-producta  very  slowly,  whureas  coniimumls 
with  a  niu]li|)Ie  carbon  bond  fonii  Ihem  instantaneously.  It  musl. 
therefore,  be  eunclniied  that  l)on/ene  does  not  contain  multiple 
carlxin  bonds,  and  that  the  carbon  atonw  in  its  molecule  are  Hnkeil 
together  in  a  sprriiil  manner. 

Other  ron^derutiimii  lead  to  the  name  t^onclusioD.     BACrcii  has 

rdiscovcrcd  ccrttun  dibasic  acids,  derivable  from  hcxamcthyleQe 

(tyclohexanc), 

CH,— CH, 

H,C  OH,, 

CH,-ai, 


by  exchange  of  hydrogen  for  carboxyl.  Removal  of  two  or  four 
hydrogen  atorca  from  th3se  hexaniethylene  derivatives  jiclds  com- 
pounds whoflp  behaviour  shows  that  they  contain  a  uiultiple  earlmn 
bonil.  It  would  be  expectwi  that  the  abstraKtioii  of  six  hydrog<Mi 
atonia  would  prmluee  a  com|X)unt!  of  an  even  inore  luuaturaled 
character,  but  a  bc-nzene  derivative  lacking  all  the  properties  ron- 
fen'ed  by  a  double  buiitl  ia  forrit-d  instead.  The  elinuaatiot)  of 
(lie  third  pair  of  hydrogen  atoms  from  the  hexamethyletic  doriva- 
tive,  unlike  that  of  the  first  and  tievond  pair,  ocea^citis  a  sudden  and 
complete  change  in  prt)pert  ie.t. 

In  imler  to  understaini  the  manner  of  Unking  of  the  betizene  car- 
bon atf>nm,  it  i&  first  iicetrssory  to  know  tlie  relative  distribution  of 
^ts  hydnigen  and  carbon  at<ima.  Two  facta  sufhce  to  dctennine 
this.  First,  no  isomrre  of  the  monosuhBtititHon-prvduda  oj 
extst,  Seeniid,  Ihr  disutistttution~prodw^fi  exist  in  three  iwmeric 
jomia.     Hence,  there  is  ouly  one  uiouubrotnobenzcne,  Cali^Br;  but 


COMTiTUTlON  OF  BENZENE.  345 

thPM  dibromobenienes  are  known,  and  are  distinguished  by  the 
prefixes  ortho,  mcla,  am!  ptira. 

h  fnilows  from  the  first  of  lhe«e  facts  that  the  six  hydrogen  atoms 
aj  bcnztmc  are  o}  equal  valur;  that  is,  replacement  of  any  one  of  them 
yields  the  same  monttsiibstitution-prmlurt.  Three  fonnulfie.  in 
wliich  the  six  hydrogen  atoms  arc  of  equal  value,  are  posable  for 
benzene: 

I.  C,(CH,),.        II.  C,(CH,),.        m.  (CH),. 

■  It  has  now  to  be  considered  which  of  these  formulte  agrees  with  the 
second  f&ct  statt^d  above. 

A  disubatitution-product  of  a  compound  with,  formula  1  can  be 
either 


(■  \^^^     or     C  (*^«^ 


No  other  isomers  are  possible,  so  that  this  formula  is  inadmissible 
as  leading  to  two,  instead  of  to  three,  isomers. 
With  formula  11  (our  iRomers  itccm  p(t»»ible: 

a.       fCHX    6.       (CHX    c.       i  CX,    d.       { CH, 
CJCHX        CJCIL  C]CH,         C.]CX,. 

(CH,  (CHX  (ClU  /CH, 

Since  the  hydrogen  atoms  in  benzene  are  equivalent,  the  CH,- 
groups  in  the  bciizcre  molecule  mtist  be  similftrly  linked,  so  that 
n  =  b,  and  c  =  rf;  in  other  words,  the  number  of  [K)s.sib|p  isnmen 
18  reduced  to  two.  Formula  II  cannot  be  accepted  either,  since  it 
also  fails  to  explain  the  formation  of  three  isomeric  disubetitution- 
productfl. 

There  remains  only  formula  III,  in  which  mck  mHton  atom  is  in 
union  wiih  one  fifpiriHifii  ulom.  Tlie  question  of  the  constitution 
of  benzene  therefore  narrows  itself  to  this:  given  a  coinpound  C,H,, 
in  which  each  carbon  atom  is  linked  to  one  hydrogen  atom,  the 
problfm  is  to  find  a  fomnila  which  account*  for  the  equivalence  of  all 
the  hydrogen  atoms,  the  formation  of  three  disubatitution-producta, 
and  the  abeence  of  double  or  multiple  bonds.  It  is  evident  that 
an  open  carhnn-ehain  formula  eaniiot  fulfil  the  prescribed  con- 
ditions, since  the  hydrogen  atoms  attached  to  such  a  chain  contain 


346 


ORGANIC  CHEMISTRY. 


ing  terminal  and  inlenne(imte  CH-groupa  could  not  be  equal.  Tho 
dx  hydro^n  atoms  can  only  he  nr  equal  value  with  a  ckxcd  chain 
of  six  C-atoois: 


BO 


CH 

0 


OH 
OH 


EuffB&gBmmtoftbeCH-groups  also  Fulfils  the  second  ooudilton, 
ae  is  ovidi'Dt  from  the  scheme: 


I 


cx 


yox      xclf     }Jca       uc^     jicB 

CU  CH  cx 

in  which  the  compounrie  C,H,Xj,  1 ;  2  =  1 : 6, 1 : 3  =  1:5,  and  1 : 4  ar<r 
isomeric ;  the  formuliau  ul  thrcc  isoiueis  is,  therefore,  also  accounted 
for. 

Ill  1hi«  9flipiii<=.  t-acli  carbon  atom  is  In  iiiiiou  with  one  hydnj^ii 
atom  mid  two  otlit-r  carbon  atoms,  so  that  IhrL-L-  bonds  of  each  car- 
bon atom  arc  uccountwl  for;  it  only  rpniains  to  aawrtain  the  mode 
of  liiikinic  uf  tlie  fourth  carbon  bond.  A  hypothi-tictil  explanation 
suggPHtt'd  by  AKMwTunNc,  and  also  by  FiAKVEH,  is  now  regardc<l  as 
aCforiling  the  moKt  probable'  explanation  of  the  observed  foctA. 
They  awiunip  tliat  Ihp  ilin^rtidii  of  the  fourth  Iiond  nf  each  C-alora 
is  t<iwnni.s  ihr  ci-nljn'  of  Uic  hnizfni-ritiie,  and  Ihat  each  bond  is 
kept  in  oquiJibrium  by  the  olht^rs.  their  niutiial  attractn>n  catiaing 
the  stabilitv  of  the  closed  chain.    This ccn/ncfonnuta  for  benzene  is 


Such  a  mode  of  Unking  is  vii)ki;<»vni  in  the  faity  senes,  bo  that  it 


ISOMERISM  OF  THE  BENZENE  DERJVATiyES.  347 

and  lacked  by  those  of  the  fatty  series.  Hence,  this  structural  for- 
mula not  only  accounts  for  the  isomerism  of  the  derivatives  of 
benzene,  but  also  explains  the  "  aromatic "  character  peculiar  to 
them. 

Nomenclature  and  Isomerism  of  the  Benzene  Derivatives 

264.  The  different  isomeric  disubstitution-products  are  distin- 
guished by  the  prefixes  ortho,  meta,  and  -para,  or  the  positions  of 
their  substituents  are  denoted  by  numbers: 


1:2  "■  I ; 6  substitution-products  are  called  ortAo-compounds. 
1:3  =  1:5  „  ,,         „         „     T?i«(a-compounds. 

1:4  „  „         „        „     para-compounds. 

The  number  of  isomeric  substitution-products  is  the  same  for 
two  similar  or  dissimilar  substituting-groups,  but  not  for  three. 
Three  isomers  exist  when  the  three  groujw  are  similar : 


X 

Adjacent  or  Vjcimil  Sjmmetricftl  Asymiuetricail 

1:3:8  1:8:5  l.d-i 

When  one  of  the  groups  is  dissimilar  to  the  other  two,  different 
vicinal  derivatives  result  by  substitution  at  2  and  at  3  respectively, 
and,  for  the  asymmetrical  compound,  substitution  at  3  produces  a 
different  compound  from  that  resulting  on  exchange  at  4.  For  four 
similar  groups,  the  same  number  (three)  of  isomers  is  possible  as  for 
two,  since  the  two  remaining  hydrogen  atoms  can  be  in  the  ortko- 
position,  mefo-position,  or  para- position  to  one  another.  The 
number  of  isomers  possible  in  other  cases  can  be  readily  deter- 
mined. 

An  alkyl-radicle  or  other  group  linked  to  a  benzene- residue,  as 


348  ORGANIC  CHEMISTRY. 

in  C,H,.CH„  or  CA-CH,-CH,.CH„  is  called  a  &ide-chain,  the 
benzene-residue  being  called  the  mtdeus.  Substitution  can  take 
place  both  in  the  nucleus  and  in  the  side-chwn;  when  in  the  former, 
it  is  usual  to  refer  to  the  ■position  of  the  substituent  relative 
to  those  already  present,  the  determination  of  which  is  called  the 
determination  of  position,  or  orientation,  of  the  substituents.  The 
methods  adopted  for  this  will  be  found  in  362  to  366. 


FKOPEKTIES   CHARACTERISTIC  OP  THE   AROMATIC  COU- 
FOUNSS:     8YBTHESES  FROM  FATTY   COHFOUNDS. 

365.  The  saturBU>d  hydrocarbons  of  the  fatty  series  are  not 
attacked  by  concentrated  nitric  nr  sulphuric  acid,  and  bxit  slightly 
by  oxidbing-agertB ;  their  hftlogrrn-siibslitnted  derivatives  react 
very  readily.  The  aromatic  differ  from  the  aliphatic  hydrocarbons 
ill  all  these  points. 

1.  Tlie  aromatic  hyflrocariionB  an?  readily  attacked  by  concen- 
trated nitric  acid,  with  formation  of  nitro-f impounds : 


C,H,.  |H  +  HO|NO,  =  C,H,-NO,  +  H,0. 

Iiiiri>b«imoe 

"On  reduction,  these  yield  amino-iierivalivcs,  which  proves  them  to 
be  true  nitroeomimunds. 

2.  On  treatment  with  concentrated  sulphuric  acid,  Uic  aromatic 
compounds  yield  eulphonic  acids : 


C,H,-  H  +  HOl-SO,H  =  C.HcSO.H  +  H,0. 

bcnxEnniuliiliuDlcacU 

The  sulphur  of  the  SOaH-p-oup  is  linked  to  a  carbon  atom  of  the 
benzene-nucleus,  since  thiophonol,  CaH,..SH,  also  yields  bcnzcDesul- 
phonic  acid  on  oxidalinn : 

3.  Tlic  aromatic  hydrocsrbonB  with  side-chains  are  readily 
oxidized  to  acids,  the  whole  side-ehain  lieinR  umially  oxidized  back 
as  far  as  the  carbon  atom  in  union  with  the  nucleus,  with  formation 
of  carboxyl, 

4.  Chlorobcnzcne  and  bromobeoMnc  have  their  halogen  atoma 
so  gtronely  attached  to  the  phenyl-Rroup,  CoHi,  that  they  arr  almost 
incapable  of  taking  part  in  double  decompositions  with  such  com- 
pounds as  metallic  alkoxidcs,  saltSj  etc. 

349 


350 


ORGANIC  CHEMISTRY. 


S66.  \'anoufl  syntheses  of  aromatic  from  aliph&tic  compouDds 
are  known ;  sonic  of  tlicnj  arc  vfn,-  readily  effected. 

1.  Wlien  the  vapours  of  volatile  fatty  compounds  ore  led  throu^, 
a  red-hot  tube,  aromatie  substances  are  amoug  the  products.     Tha* 
condenwition  of  acetyteuc.  C,II,,  to  benzene  by  this  means  is   a 
typical  example.    A  sj-nthcas  of  lienxcne  from  carbon  monoxide  is 
deacribeit  in  816. 

2.  On  treatment  with  sulphuric  acid,  nectonc  is  converted  into 
metiitflene,  or  1:3:5-Lriniethyllienzenc  (289): 

3C^,0-3H,0  -  C;Hu. 

Other  ketones  condense  »mitarly  to  aromatic  hydrocarbons. 

3.  When  liberatetl  from  its  sodium  compound,  acetoacef«lde- 

hydc,  CHa-CO-CH,  Cp^,  at   once  chanjKcs  into   l:3:5-triacetyl- 

benxcQC, 

>COCH,  1 
C4iK-<^)CH,  3     • 
^^H:H,  5 

Acetoacetaldehyde  can  be  obtained  from  acetone  and  formic  ester 
byCL.\isEN'8i'omlen&al.ion-inet]iofl  (203). 

Tho  InTcrse  roaction,  tbe  c&nvorsioii  of  aromatie  Into  fatty  com- 
pounds, is  also  tM».<til>lc. 

I.  Wlioii  b« !)«)»»- vftpour  i»  l«d  tlirougb  a  red-liot  tube,  aoetrleii«  u 
produced.  Since  ncetylcito  under  the  Mime  coodlilonsiscODTened  Into 
benwni^.  it  fftllow*  ihnt  lx)th  reactions  arc  incomplete. 

8.  Carcfhnt.  0„II,fOU),  <i:3).  is  oxidiw^  by  nitrons  acid  to 
d/Aj/f/Aij-y/.(rf.j*-(>'Mi</,  t'OOU.L'(On>,-0(OH(,-COOH.  Thecorialltu-- 
tioii  of  tliiii  acid  (ltftjfgilli)TC<i  from  iUi  combinuiK  witli  two  mokeiitMoC 
hydroxylamiiio  or  of  phenyl bydrnzin a,  whioh  prorcA  it  to  b«  n  dikotooc; 
iu«l  swflilorHl  liydrjite.  OCI,- 011(01!),.  pOMsue*  nearly  all  the  prop- 
artios  of  al'Johy<Io6  {tHH)-  On  reduction.  dihydraxytaTtaiio  acid  yields 
tartaric  nciil,  while  on  tri>atmeiit  with  a  cnncentmicd  imlutlon  of 
sadium  liydrajrcvi)  ftiilplii(«,  it  loses  two  molecule  of  carbon  dioxide, 
and  forma  the  sulplilte  derirallvu  of  glyozal. 


BENZENI  AND   THE    AHOMATIC    HYDROCARBONS    WITH 

SATURATED  StDE-CHAINa 


Ou-nuDQfaetiire  &nd  iU  B;-prodaots ;  Tftr. 

267,  Tho  arnmalic  hy'lrnrarhonH  an-  used  in  larfji?  qiinntities  in 
the  manufacture  of  aniline  dyes.  aiiJ  ary  ohtaiueil  fnim  ooaUlar.  a 
by-pixxliict  in  tho  timimfaciiireof  gas.    A  short  dcscriptirtn  of  thig^ 
proc<«s  will  not,  ]x  oul  of  place,  since  it  al«j  j-iclils  olhi-r  products 
of  great  iuiportaiice  in  the  manufacture  of  organic  chcmicali!. 

CoaJ  is  Rradufttly  heated  in  iron  nr  clay  retort*  of  a  Q-ehaped 
cross^oction .  bring  finally  raised  to  a  n>d  heat:  tho  gases  and 
vapours  are  rpmoved  as  cninpli-lely  as  p^isaiblt-  by  moans  of  vx- 
haustere.  Coke  remainn  in  the  rctwrtu,  and  is  crtiployed  as  fuel.  an<l 
in  many  metjUlurB;i''-al  pnmi-ssi-a,  allhiiii.gh  for  the.  latter  purpose 
the  coke  has  usually  tu  be  pn-pan-d  \>y  special  nicand. 

ITic  distillate  conlains  three  main  products.  1.  Gasee  (illumi- 
nsting-gss).  2.  An  aqticouR  liquid,  cDnt^inin^  ammonia  and  other 
baaie  subBtanecs,  siicli  as  pyridine  bft.sps.  3.  Tar,  Tliese  are  Bepa- 
rated  from  one  another  as  completely  as  possible  by  a  series  of 
treatments.  The  crude  gas  is  passpfl  over  iron  ore.  to  remove  ihe 
cyanogen  derivalivefl.  The  piirifying-niateria!  Ih  employe<l  for  the 
preparation  of  potassium  ferrocyanidc  (843),  an  important  soorce 
of  the  cyajiogon  compoiindB. 

Tar  is  a  lluek.  black  liquid  n-itli  a  cbaracterisllc  odour.  Ita 
colour  is  due  to  susjiendeJ  particles  of  carbon.  It  is  a  complicated 
mixture  of  neutral,  acitlic.  _and  basic  substances.  The  first  an-  prin- 
cipally liydrocarbons,  chiefly  belonKinp;  to  the  aromatin  Hc-rics. 
About  5-10  per  eent.  of  the  tar  consista  of  aapht  halene,  and  1  -1  5  per 
cent-  of  a  mixture  of  b4'nzene  and  toluene.  Phenol  is  the  principal 
acidic  constituent  of  tar.  Basic  subcitanceK  are  only  present  in  smi 
quantities,  the  chief  being  pyridine  and  quiuoline,  and  their  homoj 
logucs. 

3SI 


AROMATIC  HYDROC^RBOffS. 


ii3 


la  the  sjaitiesia  of  Friedgl  ami  (..'lUPW  more  thao  one  allcyl- 
group  in  genernll}'  inlmituciMl,  the  Toonosubslitution-proOucts  anil  the 
bigber  8ub»tit  utiuD-pruducU  bving  Bimultaaoouslr  fomicct;  tliv  Uonw- 
logaee  ar«  soparetecl  by  fructionttl  iIiatill»tioti. 

Tbift  r«actii>u  ccnostitules  a  luetLod  botbi  lor  lliti  buitiingr  up  (tnd 
brmlcin;  down  of  il  lijdroeaibon.  When  loliieno,  ('•HcCHi,  is  Inatod 
with  itLuminium  chlf^ridv,  Wnzctii;,  Cdli,  and  xylouo,  t'*U,(CHt>i.  arc 
fomwU.  The  nlkyl-groupB  of  one  Iiydrooarbon  are  exchanged  for  the 
hydroften  of  the  otbor.  TbU  leaction  cau  alio  be  brouRbt  tiboat  bj 
thanetion  of  oosoentrared  sulphuric  acid  upon  aromatic  hjrdrooar- 
boDi  with  a  natuber  of  side^hftius, 

3.  Like  the  satiiratcd  tatty  hydrocarbons,  the  aromatic  hydro- 
carbons are  obtfliin\l  by  (he  distillation  of  the  calcium  salta  of  the 
aromatic  acidfl  with  sotla-linte: 


C^,.|CO,ca*+  caO|H  =  CaCO,  +  C^,. 

4.  Ileiizciie  and  lU  homologucs  can  be  obtoiiuxl  by  htatiiig  the 
eulphonic  acids  n-ith  sulphuric  or  hydrochloric  acid,  \h^  decom- 
position being  facilitatc«l  by  the  i»tniducti<m  r)r  Huporhvated  Ht«ii.m: 

C,H,(CH,),|Sf>,H  +  HOlH  =  C,H,(CH,),  +  H^.. 

Thi.t  invllingi  cati  bi>  eiiiployed  in  the  eepuratioD  of  the  aromatic 
hydrocnrbotig  from  ihi'  jinnillUw,  Wh«n  varmod  with  cunceul ralwl 
Bolphuric  acid,  tins  formur  iirc  converted  into  sulphonlc  wcids  iwluhin 
In  water  ;  tho  pnmfiiiis  are  unaotwl  on  and  are  iasolublc  in  wator,  so 
that  n  lucchAnlca]  a<'i>aratio[i  is  thim  |nMAihli\ 

Till*  nmtliod  win  also  he  appHcHl  to  ihe  si^iaratiun  of  the  aromfttic 
bydrocnrbouB  tbomsolvL'it,  una:  iraino  oF  tbem  arc  more  readily  coo- 
rert«d  taloBulptiouic  atiids  Uiitii  othort. 


6.  Ity  heating  an  alct^hol,  aii  aruriialio  tiyd  x>carbi>n,  ant)  zinc 
cWoridf  at  270°-300°.  The  zinc  chloride  plays  the  part  of  a  dehyd- 
ratiiig-agi'Ht: 

cji,|H+~Hoi.cji„  =  cji,-c,H„  +  n,o. 


iS4 


ORGANIC  CHEMISTRY. 


IndiTidnal  Mem'beri. 

269.  Bonzcne  and  the  aromatic  hydrocarbons  with  saturated 
sltli-cliaiiis  are  colourless.  Idghly  refractive  eiihatanpcs,  liquid  at 
onliimry  tL-inperatunw,  and  pnwcsfiing  a  characlcristic  odour. 
T1k->-  an;  immiscible  with  water,  but  nux  ill  all  proportions  n-ith 
strong  alcohol.  Some  of  th(^ir  physical  properties  are  iudicated  in 
tlie  table : 


1                      Kane. 

Fomiuh. 

unSq^ 

C'.H, 

L-,H,-C1I, 
.  ,,    ^CU,  1 
■^•"•^-fH.  3 
C,[l.fCll.i.<):3;9) 

a.H..c,iu 

C.H,-CliiCII,), 

V  II   .^*'"'                ' 

Bor 
no* 

189' 

164* 

IHtf" 
1&3' 

<l-874  («)"> 

o.sse  (is*i 

0.881    (0*) 

o.aia  (i4'> 

0.888    (0-1 
0-Mfl  (16*1 

0-8ce<so*) 

I>ourupvlLt<tiKune  (Cumcne). . . 
jvMvtiiyllaoiiniiivllwn  acne 

Benzene  was  discovered  by  Faraday  in  1825  in  a  liquid  obtained 
by  siibiiiitliiij;  cuul-^ati  to  pn^esurc. 

Xylene,  or  diiiifihylbt'ii)!t'iH-,  c-xii(t8  in  tliroo  istjtiioric  forms; 
Tfi-xylirric  in  tliK  priiifiiml  toiistilueut  of  the  xylene  in  tar,  being 
70-85  per  cent,  of  llic  whole. 

The  iHomerlo  xylenes  can  only  bo  sepnraled  with  difflculiy;  ili«ir 
boilirg- points  lie  vory  eWo  tngflhsr,  Ihnt  of  o-xyl«iM  being  14**, 
wliilo  irt-xyluiie  nnd  j><:tyler«  btjjl  ttt  130°  And  13S*  mpcctivoly. 
ThU  makes  ilimr  sepanilion  by  rnictioiiHl  disiillalioii  iniprAeiicjtl>Io, 
bill  it  can  be  clCe«tod  by  Iroatiug  tlioiu  with  sulphuric  acid  at  onli- 
nnrj-  tempernturM;  m-zjleiie  and  <>-x>*I«tiv  gu  into  Bolutioii  na  gol- 
phonio  ft(!i<I«,  wiillp  p-xyU-Tio  wmdins  undlMolvecl.  The  tnlpboDie 
acidn  of  the  tnefa-corn pound  nnd  urMr'-«onipound  e&u  bo  Hparatw]  by 
frsoiioiii^l  crysinllisAtiou  of  tliifir  sodium  sails,  ibe  <trfAo-salt  cryslalli^- 

CymeM,  C„H„,  ia  closely  related  to  the  torpones,  C„H,„  and  ta 
the  camphors,  C,oH,,0,  Bince  it  can  be  obtained  from  Ihem  in  various 
ways.  Cyineim  is  a  coustitiient  nt  certain  etbercftl  oils,  such  aa  oil 
vf  carravxiy,  oil  of  thyme,  and  ad  o/  eucalyjitut. 


AROMATIC  HYDROCARBONS.  355 


HydrogeQ  Addltion-prodaots  of  the  Aromatic  Hydrocarboni. 

870,  When  Ibe  aromatic  hydrocarbons  take  up  two  or  fonr  hydro- 
gen atoms,  they  lose  their  aromatic  character  and  acquire  properties 
peculiar  to  unsaturated  compounds  (468).  The  centric  bonds  may 
be  supposed  to  be  broken,  with  formation  of  double  bonds  (BIB): 


H  H 

H        H  H.f^'^^H, 


■KDi 


u 


K^ 


KNh"*'h 


H. 


H  H 

Dlhf  dro  be  iiwno 

Dihydrobemme,  CtH.,  for  example,  reacts  with  a  Bolutioa  of  per- 
manganate and  sodium  carbonate,  and  also  adds  on  four  bromine 
atoms.  Tetrahydrobemene,  C,H„,  readily  adds  on  two  bromine 
atoms.  I 

When  six  hydrogen  atoms  are  taken  up  by  benzene,  there  results 
hexamethylene,  which  melts  nt  3°  and  boils  at  608°;  it  has  the 
character  of  a  saturated  liydrocarbon  of  the  fatty  series.  Hexa- 
methylene,  (CH,)^  or  C,H,„  and  some  of  its  isomers,  are  pi'escnt  in 
Busstan  petroleum;  they  are  called  naphthenes.  They  can  be  i'ec<^- 
nized  as  addition-products  of  the  aromatic  hydrocarbons  from  their 
yielding  nitro-deri  vat  ires  of  these  hydrocarbons  on  treatment  with 
nitric  acid.  They  differ  from  the  isomeric  olefines  in  not  possessing 
the  power  of  forming  addition-products,  and  in  their  stability  towards 
Baeteb's  reagent  (ISS). 

Eexamethylene  and  its  Iiomologues  can  be  obtained  by  the  catalytic 
action  of  freshly- red  need  nickel  on  a  mixture  of  hydrogen  and  benzene 
or  its  homologues,  the  reaction  taking  place  at  a  comparatiTely  low 
temperature  ^,  126,  and  1S8). 

W.  H.  Pkbsin,  Jun.,  has  prepared  hexamethylene  synthetically  in 
the  following  manner.  Chlorobromotrimethyleno  reacts  with  sodium 
etboxide,  yielding  a  chloro-ether : 

Cl-CH..CH,.CH,-Br  -h  NaOCH.  —  C1-CH,.CH,.CH,.0C.H.. 
This  compound  is  treated  with  sodium : 


aCltH,O.CH,-CH,-CH,.[Ci  +  Nn,|  -*  C,n,0(CH,>,-OC^(. 


35^  ORGANIC  CHEMISTRY. 

This  doable  etber  ia  tbeo  treated  with  hydrobromia  aotd, 

C,H,0-{CH,>,-OC,Hj  +  2HBr      -♦  Br.(CH^,-Br. 
With  sodium,  the  reeuItlDg  dibromide  yields  hezamethyleae : 


OH,-CH,— CH, 
CH,-Cir,-CH, 


Br 

Na 

+ 

Br 

Ka 

CH,— OH,— OH, 

CH,— OH,-OH,' 


MONOSUBSTITUTION -PRODUCTS  OF   THE  AEOMATIC 
HYDEOCAHBOHS. 


I.     MOVOBULFHOnC   kUlDB. 

271.  The  formation  of  these  f«nipniinds  liaa  been  described 
already  (26&);  they  arc  produced  by  the  action  of  coocentmt*d 
sulpliuric  aciti  upon  aromatic  compounds.  In  order  to  separate 
thera  from  the  cxco.'B  of  sulphuriu  acid,  use  is  made  of  the  ready 
solubility  of  thfir  calfliuiu  aiid  barium  salts  In  water;  the  proceas  is 
mmilnr  to  the  Bpparatioii  uf  ulhyl  hydruypn  sulphate  from  sulphuric- 
acid  (60).  They  ran  also  be  separated  from  thdr  coiieeiilratc<i 
solution  containing  eulphuric  acid  I>y  the  addition  of  cotmnun  salt 
until  no  more  will  tlisaolve,  when  the  aodiiim  salt  of  the  aulphontc 
acid  separates  in  the  solid  state.  'Vh\s  h  dissolved  m  water,  the 
e<iuivalent  quantity  of  mineral  acid  added,  and  the  free  Biilphonie 
acid  isolated  by  exi  raetinn  with  eth<T 

The  sulphonic  acids  an-  cnloiirlrw,  crystalline  substances,  gen 
erally  hygroscopic,  and  rrmiily  soluble  in  water.    They  can  be 
rrconvrrted  into  tlir  iironiatic  hydrocarbons  by  treatment  al  a  high 
temperature  with  hytUvchloric  acid,  or  with  superheated  slcain 
(268.  .1). 

Most  of  the  sulphonatfs  ervstallize  weEl,  and  are  employed  in 
the  purification  of  tlie  sulphonic  aeid^.  On  treatment  with  phot* 
phoruH  pentachloride,  the  latter  are  converted  into  chlorides: 

C,H,-SO,-OH  -  C,H,.Sa-Cl. 

The  milpkonic  chloridex  are  very  stable  ton'Rrds  cold  water,  being 
but  «lowly  reconverted  into  sulphonic  acids. 

Tlie  stUp/iaiuirnnke  are  formed  by  the  action  of  ammonium 
cjubouate  un  the  chlorides: 

C,H,  •  S0,G1  -*  C  JU  •  SO,  •  NH,. 

They  are  well- cryatalli zed  compounds;  the  determination  of  their 

3S7 


3fio 


ORGANIC  CHEMISTRY. 


Individual  Members. 

}^<mt>ehlor<^cnza\c  is  a  colourless  liquid ;  it  boils  without  decom- 
poRitino  at  132°,  ami  hsB  a  specific  grax'ity  of  1-106  at  20".    Mono- 
brnmtibmsene,  B.I'.  157°,  sp.  gr.  \-\9l  ftt  20°.    Monmodobemene^i 
B.P.  iss*,  up.  gr.  1  .S61  at  O". 

Bctizyl  chtaridt.  is  a  colourless  Itijuid  of  stuppfying  odour,  inten- 
siiird  by  warming:  it  lioiis  at  ITS*^.  ami  hasiisprrifi<;p"avity  of  1  •  113 
at  15°.  licneyt  iodide  is  prcparrd  Ijv  heating  benxyl  chltiridr  with 
potaasium  iodide;  it  melts  at  24^  and  dccompo^ee  when  boiled. 
It  ha«  a  powerful  -aiid  uiiboaraljly  irritAting  odour,  productive  of 
tears. 


lodobenune,  and  other  Iodine  oomponndB,  snbfttituted  hi  the 
DoeleUH,  un  add  on  twu  atoms  of  ohinriiie,  wiUi  formation  of  com- 
pounds snoli  as  pJietij/tiodiiln  chloride  or  iodfAtmetM  dtchJoriilt, 
0*Ui-ICli.  Wlica  digtatod  ffitbalkiitui,  tbeae  givo  lotiooD-wmpoumf^, 
such  lis  iodoMlKjitfii^  C*UfTO,  wbicb  are  amorphous,  yellowisb 
solids.  Wh&Q  heat<xl,  or  oxIdtE«d  with  bleaohing-imwdor.  these  OOID' 
pounds  yield  iodox}/-<ompounds  (German,  fodovtriiinduu^t), 

SO.H.-IO  =O.H.-I  +  UH.IO,. 
lodiraytwnteiM 

Todaxyftensene  \%  or3»talliD»  and  explodoa  wbcn  heatad. 

T)ie  coimtituMon  of  these  compounds  is  inferred  from  their  readf  I 
coiiv<.-i>ioii  into  iiKliilx^'iixerift.  tijfs  l>eiiit:  elTected  for  iodoaob»niea« 
moans  of  potassium  iodide.  And  for  ttxloxyboniene  by  hjdrocenj 
dioiide,  ■mth  evolution  of  oxjrgeiL  Tbno  siitMlances  wonld  not  be  so^ 
readil)-  <X)nT«rted  into  iodobenxene  if  tbe  oxrgeu  were  attacbed  to  llw^ 
l>eiix«i:ii--nucleu&. 


<^ 


in.    MOKOHTOEIC  PHEROLS  JUTD   ABOHATIC   ALCOHOLS. 


274.  The  hydmxyl-compounds  of  the  aromatic  hydrocarlKins 
display  the  same  riiaracteristic  difTercnce,  occasioned  by  the  utiion 
of  the  sulwtitueiit  with  the  nucleus  or  with  the  side-chain  bo 
the  halogen  derivatives  (278).  The  Oil-group  in  phenoi  (carbolic 
acid)  .CgHj-OH,  is  in  union  with  the  micleua.and  posseasea  a  chaioctcr 
unknown  in  tlip  fatty  serips.  A  enmptmntl  suph  as  bemyt  alcohol, 
C,H(*CH,OH,  winwi*  cijiLstitulion  follou's  from  its  oxidation  to 
bonrnic  acid,  CJlj-COOH,  displays  moat  of  the  properties  cbsiao 
leristic  of  the  aliphatic  alcohols. 


PHENOLS.' 


36r 


I 


A.       I'HRNOLS. 

Phenol  and  eoiiic  of  its  humolo^cs,  such  as  creaol,  etc.,  are 
found  in  coal-lnr,  by  the  fractional  distillation  of  wluch  they  are 
ai'ciimulntcd  in  thp  carbolic  and  creosote  oils  (267).  They  are 
isoliiterl  by  shaking  these  fractions  up  with  caustic  alkali,  wliieh 
dissolves  the  phenols,  leaving  the  hydrorarbons  behind.  They  are 
liljerated  from  the  solution  nnlh  Riilphiirir  acid,  and  are  then  sepa- 
rated by  fractional  distillation.  By  far  the  larger  proportion  of 
the  phenol  found  in  commerce  is  obtained  from  this  source. 

Plienol  and  its  liomoloEuea  can  further  be  obljuned  by  the  foUovr- 
in^  methoda. 

1.  By  fusion  of  the  sail  of  a  Bulpbonic  acid  with  alkali : 

C,llj-S0,K  +  2K0H  -  CHj-OK  -t-  K^O,  +  n,0. 

2.  By  tbt-  aelion  of  iiitmiia  acid  on  aromatle  aiiuncs,  a  method 
analogous  to  the  proparatiw  of  alcohols  of  the  fatty  series  from 
amines  (72).  But  whereas  on  acting  upon  an  aliphatic  amine  with 
nitrous  acid  the  alcohol  is  produced  din'i-tly,  in  this  rase  ven,'  im- 
portant intermediate  products,  the  diiuoniuni  compounibi  (302), 
can  be  isolated. 

3.  Ry  the  artion  nf  oxygen  upon  l)rnzCDC  in  presence  of  alumi- 
mum  chloride,  phenol  is  ft.niied. 

Properties  of  tb«  Fhenola. 

279.  The  phenols  are  in  some  reupcets  comparable  with  the 
t«rtiar>'  alcohols,  since  in  both  llic  hydroxyl  is  linked  to  a  eurbon 
atom  in  direct  union  with  three  others,  although  in  the  piienols  one 
of  thede  bonds  ii  of  a  special  kind.  IJke  the  tertiary  alcohols, 
therefore,  tlio)'  cannot  l^e  oxidised  to  aldehydes,  ketones,  of  ■It'ids 
coaCaining  the  same  number  uf  C-atonis.  The  phenols  <Adubit 
many  of  the  charHcteriHtieB  of  the  aliphatic  alcohols;  tlu<y  arn 
oa|mble  of  fortning  ethers,  whon  alkyl  habdes  reset  with  their  alkali- 
saltit;  they  produce  esters,  forming  acetates,  for  example,  with 
acetyl  chloride.  Phoaphorua  peutachloride  substitutes  CI  for  their 
OH,  although  not  so  readily  as  in  the  fatty  series.  Cut  in  addition 
to  these,  the  phenols  possess  .ipccial  properties  due  to  thetr  much 
stronger  aeidie  character.  When  describing  the  separattoD  of 
phenol  fn)in  oarlioliu  «)il  (267),  it  was  mentioned  that  they  disscilve 
in    caustic  alkahs,  formhig    /Vcrinruicji,  such  as  C^II^-ONa.    The 


3<» 


ORGANIC  CHEMISTRY. 


alcohob  of  the  fatty  eerios  do  not  possess  this  property  in  tlie  sam€ 
degree.  Those  which  arc  iiiRrthible  in  wntcr  do  not  dissolve  in 
caustic  alkalbi,  and  are  only  convcrtetJ  into  metallic  aIkoxidi>s  bj'  the 
flplinn  of  ihp  alkali-nietals.  This  increase  in  acidic  character  can 
only  be  (iccasiotKHi  by  the  iircsicncn  of  the  phrnyl-gmup;  in  other 
words,  tiie  jiiu-nnl-ffrvup  luia  a  more  nttitUivc  cJiaracier  than  an  atJcyl- 
graup.  Iti  other  rcipTCts,  Ihc  pheiitjls  arc  weak  acids;  their  aqueous 
solutions  are  bad  conductor?  of  electricity,  and  thopKcnoxides  are 
decomposed  by  carbonic  acid. 

It  is  thus  seen  tliat  the  prnperties  of  the  hy<lroxyl-gn>up  are 
considerably  nio<lificd  by  union  with  the  phrnyl-iaT""ip.     Inversely, 
the  itifliicncc  of    Ihr  hydnixyi-prtrnp  on  the   U-nzeiic-nucIeus  is 
ecjualiy  marked,  itiakiiiR  the  ri:iiuiiim)|;  hydroKcn  atoms  iimch  more 
readily  sulwtitulcd.     Henxene  is  only  slowly  attacked  by  bromine 
at  ofiiinary  temperatures,  but  addition  of  bromine-water  to  an 
aqueous  solution  of  phenol  at  once  precipitat«i  trihromophpnol — 
a  reaction  employed  in  il.s  ipiantitativc  cstimatioii.     Thewmver^iion 
of  benzene  into  nitrobenzene  ncccssitattsi  the  use  of  conccntrati-d 
nitric  acid,  but  phenol  yields  nitropiiciiol  on  treatment  with  the 
dilute  acid.     I*heiiol.s  are  also  much  more  readily  oxidized  than  the 
aromatic  hydrocarbons. 
i~'*On  distillation  with  xinc-dust,  the  phenols  are  reduced  to  the^ 
I  correspoiidiiig  hydrncarbuns.     They  can  be  delectctl  by  the  forma-  i 
j  tion  of  a  violet  colouration  when  ferric  chloride  a  added  to   their  I 
■(_a<iucou8  solutions.  '"^ 

IndividQal  Members. 
278.  Phenol,  or  carMic  acid,  is  a  (rolourlcss  substance,  crj-stal- 
lizinK  in  long  iici-dles.  It  melts  at  39-6",  unci  b<i)il»  without  decom- 
pcwitiou  at  181°.  It  has  &  characleriBtie  odour,  and  stn^iy:  antiseptic 
properties.  It  was  formerly  largely  employed  in  surgery,  but  to  a 
gn-at  extent  its  place  lias  been  taken  by  mercuric  chloride,  or 
ccirrodive  Miibliuiati;,  HgCl,,  Phenol  is  soluble  in  water,  1  part  dis- 
Bolving  in  15  at  16°;  it  can  also  dUsolve  iivatrr.  On  account  of  the 
email  molecular  weight  of  water,  anti  the  high  molecular  lowering  of 
the  freciiing-puint  of  phenol  (75),  a  aiuttll  perceutage  of  water  cai 
phenol  to  tw  liquid  at  ordinary  tempernture.s  (14).  It  follows  fror 
the  ei^uation  ,!iV/  =  75,  in  which  M  is  the  molecular  weight  of  Wftt 
(IS),  that  .4 ,  the  lowering  of  tliK  freczing-poiiil  occasioned  by 
presence  of  1  per  cent,  of  water,  is  about  4'2^, 


PHENOLS  AND  AROMATIC  ALCOHOLS. 


363 


The  hydrnxytoluenes,  Cn,-C4I,'0n,  are  called  crtsols:  tboy  jirc 
preecnt  in  coal-tar,  l)ut  are  usually  prepared  from  the  corrL-spDrul- 
i«g  amino  compounds,  or  sulphonic  acids.  On  oxidation,  they  arc 
completely  decomposed,  but  when  Uie  hydrogen  of  the  hydroxyl- 
group  \i  replaced  by  alkyl  or  acetyl,  they  can,  likf  toluene  itself, 
I>e  oxidized  to  the  corresponding  acids.  Tlie  creaols  resemble 
phenol    in   their    behaviour   towards    bromine- water.     jvCrcao/, 

CH,<f      X*^'  '^  *  decomposition-product  of  albumin. 


Thyittol,  which  is  also  usc<i  as  an  antiseptic,  is  hydroxycymene, 

4- 


\CH(CH 


:ccH,),f- 


Acid  sulphuric  cstcn  of  pti«tiol  nre  prasoiit  In  urine ;  thej  rcaalt 
from  tlio  Tlih  noil  tilt  ion  (itutrcfiictiDn)  nt  iilljiiinitjs,  since  the  quautily 
of  tbem  prctcut  ilopcnOs  upon  tbo  oxtunl  of  tkia  process. 

n.      AHOMATIC  ALCOHOLS. 

277.  A  type  nf  these  coiiipiimdK  !«  iurtuyl  alcohol,  CcTTj-CHjOII, 
which  possa'wns  nearly  all  ilic  properiics  of  un  alipliatir  alroho).  It 
can  be  obtainnt  by  tn-atincut  of  benzyl  eliloridc  witti  potafisuim 
acetate,  and  sapomficotioii  of  the  ester  of  acetic  acid  Ihu-s  farmed. 
It  reacts  readily  with  phoephonw  pentachloride,  yielding  benzyl 
chloride,  and  forma  esters,  ethers,  etc.;  being  a  primarj'  alcohol,  it 
can  be  oxidized  to  the  correHpnndtng  atdchyde,  bemaldditfde.  and 
also  to  htmoic  add.  It  (litT<'r»  frtmi  the  aliphatic  alcnhnlt  in  its 
behaviour  towards  sulphiirin  acid,  which  causes  resinificatioo,  in- 
stead of  the  formation  of  th»  corrcspunding  sulphuric  ester,  nenityl 
alcohol  poeMSscs  no  phenolic  properties;  it  is  insoluble  in  alkalis, 
and  docs  not  yield  the  characteristic  phenol  colouration  with  ferric 
chloride. 

lieneyl  alcohol  is  a  liquid  which  dissolves  with  difficulty  in  water; 
it  boils  at  206°.  and  possesses  only  a  faint  odour. 

^«     -      «•  17.     STTLFRtnt  DESITATITU. 

Ttiiophenai,  C,n,-Sn.  cnn  be  obtaiDed  by  heating  phenol  wUh 
pbMpliorus  p«nlasu1i>bid<!<,  1>,S^  or  by  reduction  of  Ibo  chlorido  of 
bcnieoMu  I  phonic  acid.  It  bag  all  the  propertiei  of  iIiq  mvrcaptntii, 
partk-nlarly  tite  power  of  forming  wlt«.  Like  taoit  v<4atil«  •alphtiT 
MHopouiiils,  il  has  a  diaagneobla  odour. 


MONOSI  TRO-DERiyATiyES. 


3«5 


For  the  preparation  of  aromatic  nilro-coinpmirKL'*.     The  substaiit'e 
is  treated  with  n  mixture  of  nitric  and  sulphuric  acids: 


C.H4- 


•XO,  =  CANO, +  H,0. 


.^^rtJriomed  in  the  nitration  would  dilute  the  nitric  acid  and 
nmrff ^  ictlon  if  the  sulphuric  acitl  were  not  present.  The  mure 
alkvl-croups  there  are  in  union  with  the  benzene-inicleus,  the  more 
readily  is  the  introduction  of  nitro-groups  effected. 


FropttTtlM. 

280.  The  mononitro-cnmpound-s  are  very  gtablo.  and  can  be 
distillerl  without  decomposition;  their  niiro-groups  are  verj-  finnly 
attached.  Vnlikc  the  primary  and  peeondary  nitro-compounds  of 
the  fatty  serjea,  the  oroniaiic  nilro-de-rivatives  do  not  contain  hydro- 
gen replaceable  by  mctalH,  since  the  nitro-group  in  them  is  linked  to 
a  tertiary  earbou  atom;  tsueb  an  exchange  is  therefore  impu.'sible 
(76).  On  reduction,  the  nitro-eompoimds  yieki  aniinE«,  and  the 
reaction  can  be  so  carried  out  that  various  intenuediatc  products 
arc  isolated  (289). 

Moat  of  tlie  nitro-com|)ound3  have  a  pale-yellow  colour,  and  an 
agreeable  odour;  they  ore  usually  liquids  heavier  than  water,  in 
which  they  are  iufioluble.    They  arc  volatile  with  Bteam. 


Individual    Hembera. 

jVfc(ro6fn»rw  ia  manufat'turptl  in  large  ijuantilies  in  the  aniline- 
dye  industry.  Cast-iron  vi-ssoU  litteil  with  a  stirTing-apparftru.s, 
and  kept  cool  by  water,  are  employed.  They  are  charged  with 
berutertc  into  which  a  tuixture  of  nitric  and  sulphuric  acids  is  allimvd 
to  flow.  At  the  end  uf  tlie  reaction,  the  iiitrobetiztme  flouting  <m 
the  surface  of  the  sulphuric  acid,  which  contains  only  small  tjuaiiti- 
Ue^i  of  njtrie  acid,  is  wuahed  with  water,  and  purified  by  distillation 
with  steam. 

NitTobenrene  Is  a  yellowish  liquid,  with  an  odour  resembling  that 
of  IjJtter  almonds,  for  which  rL'aatm  it  is  used  in  perfumery.  Its 
boiUug-tx>iiil  is  208°,  its  mclting-poict  b-h",  and  its  specific  gravity 


3W 


ORC/tNIC  CHEMISTRY. 


1  •  19S7  at  25".    Ita  pn'paratioa  od  Uie  lari^  scale  is  carried  out  in 
order  to  obtain  aniline  by  its  ro<luctioD  (283  and  292). 

SUrotaluttirs. — When  tolufiie  w  nitrated,  the  chief  products 
are  the  wr(Ao-c(>in]5ouiid  anil  para-nompamvi,  the  mdjt-cnnipound 
being  only  fnmitnl  in  Iratit-i*.  NS'hii'H  i>f  the  uvo  idoiiifrs  is  i>n«luced 
■□  greater  quantity  dcpL-nds  upon  iht--  iiti-thcid  of  lutratJon  unploycd 

OH    1 

Vam-nitrotoluene, C,li,  <  v,^  a<  is  iM>Ii<l,  melting  at  fil",  and  can  be 

obtained  pure  from  ilte  liquid  inixlure  of  tho  isomers  on  cooling; 
tin-  pn.:paraliuu  of  llii'  pure  ori/io-comixiund  '\»  niom  troublesome. 


PbeDytBitrometliaae  and  the  pMndo-ajcid». 

B81.  PhtiU'initromtthane,  CtHfCHiNOi,  is  an  nroinntic  compontid 
with  a  nitro-gruuptu  tin-  aid«-uliitiii;  iliin  is  vvr<)(!nl  frDin  ils  (ormatior 
b}-  lliQ  acliuii  uf  boiixyl  clilorMn  or  loiliil«  «ii  Kilvcr  iiiirilu: 


CiH»'On,|tJH.  AgfyO«=  C,H..CH,NO.  +  AgCl. 

It  can  bi)  reduced  lo  Iwiistyliimiun,  which  proves  It  to  bu  n  true  nttrc 
oumpoiitKl.  I'hetiylnilromclhtiiK'.  ikti<]  Wm  (lurivntifM  Willi  aulMtitii<-ni» 
ntt.iciit^d  in  iliit  niioloiui,  pi)i<A<.'EJi  \\iv  rtntnrkivblo  proptTly  of  uiaI- 
ing  iti  Iwo  modiflealioiie  wbit'li  ar«  readilj-  t ntiiGfomii!d  into  oacli 
other.  I'hfnyhtitrtiiiii'thnne  ii«  H  litfiiiJ.  whoso  aqueons  solution  does 
not  rvact  vrith  f«rrio  oliloritlo.  Wlit<n  it  io  oonvertod  into  iu  eodiom 
di'rirnlive  by  tho  nation  of  sodium  jilkozide,  mid  BubeVfiaoiitly  set 
freo  by  tbc  iiddiliuii  uf  a.  sirotig  mitivral  acid,  n  ciyslalhtw  MibufAnce 
of  tho  enmo  conipoeiiion  as  iilifnyhiitromechane  nepnntas  oiit  ;  tha 
n(]uooiis  solution  of  ihin  anm)K)iiiid  gives  n  coIoiirKlimi  wii.)i  ferric 
rhlwidp.  AffiT  sonii^  houre.  Itit-ac  crystalsiin?  oomplctcly  rcconTertwl 
into  onliiinry  litpiid  {itiviiytiiiirumvtbniio.  tl.  is  very  ptotnbl4>  that  tbd 
eodiiim  coni)Kiiiiid  mid  llic  anst^blc  modifimt ion  corrasponding  to  U 
bnvu  iIji.-  coiiNliiiitioii 

CH..CH:NO.OH 

Thepres«no«  of  aliydroxyl-tETotip  ixprnvi-il  byihofornuilionof  dibtfim-- 
hffdramtaie  aetd  on  troatnicut'  with  bunutyl  clilondo  ; 

C.U.-CII:3If  +CIOC.C<H,-.C,H,-CH-.Nr  -• 


*ONa 

Elinjiuciliuia 


■  C.H.-CO— S— O-OCCFU. 
U 

IMbeailirilromuiUc  M4d 


PHBKYLNiTROMBTHANE  AND   THE  PSEUDO-ACIDS. 


367 


Aimtlior  |iroof  of  Ibc  prosuitoa  of  a  hydroxfl -group  is  ihat  JHnnuro. 
compoQiiilfl,  unlike  ordinary  nitro-compounda,  react  rigorously  with 
plifiiiyl  ixocyanAle  (M8)  ai  low  teDiji«rH lures. 

From  lh«  ii[vi:rtliiifj  it  uiny  bu  ddJiiced  thnt  when  pliffnylnilrome- 
IhHne.  (',tff('ll,NO,.  is  rouTcrleO  intu  »  luill,  it  first  cbn[i);cs  lo  an 
bomerio  moilifieniiun.  luvi-racly.  when  it  in  net  free  fmni  its  Bodium 
cotiipouiid,  ibe  iso-moiliUcation  is  tint  producdd,  aiid  slowly  cliuugea 
to  tlio  ordinary  fiiriu. 

Tho  dJhilv  AciiiH>us  KOUiliun  or  llio  inrfo-ititro-dcrivnlive  of  plicnyl- 
iiilrnmcihanc  hffards  n  strikiDg  example  of  lliia  phaaoinoiinn.  Tliis 
iiomptmiKl  is  eolourlesB,  but  ils  sodium  salt  has  a  dwp-yellow  «o)otir. 
Ou  lliu  itddilii>a  of  an  cquivnlout  quiintily  of  bydruutilorio  Hcid  lo  its 
dM|)ly  linlod  •olntloii.  ilie  yollow  cnlour  diMppoara  Ki>m«wliiit slowly, 
iadicaliog  tbo  vonvcrsiou  of  llio  isi>-i;oiDpvuiid  iuto  llio  uorroBl. 

TliBdisctmi^sor  tlioi'i^biir  Is  altviiik-il  by  iinollivr  pbcnomcnan ; 
tfae  electric  coiwluciivity  of  tlio  l»|uid  ia  considemUy  Rrealer  iinuio- 
dlatnly  after  ilie  addition  of  Iho  liydrcclilorio  noid  than  it  u  wvprnl 
miiinles  litlor,  >vlieii  tbc  colour  Ijfis  Doarly  \aiiislicd.  Tlic  cx|ilHiiiitiua 
of  lliis  is  lliHt  iliv  iHO-form  in  a  true  acid,  and  Is  IlKTufore  a  pomliiclor 
ID  aqueous  aolutioii,  wlule  tlio  solution  of  tlio  uortoal  muditicatlon  is  a 
noQ-oouductor,  and  tbvruforu  [himosu-s  tio  acidic  ohat^cier. 

Coiupoutids  which  cbaii|;«  to  an  isi>->i>odiDcatioti  ou  furuintiaii  of 
motHllindBrivfiiivea.  are  called  ntetidti^eii/s.  In  addiiion  to  iilu-iijl- 
nttromotliuTmaud  its  niig-suUtt Itutt-d  derivatives,  other  psoudo-ocidt 
are  known,  most  of  wliicb  nro  Tiiiru-cnnipoiinds, 

Bcftidvs  Hid  propurti<«  itidieatvd  above,  the  pseudo-acids  poSBess 
otlicnt  by  wbiclj  Ihcy  mny  bu  di-l«M7tfd,  It  liiu  just  lieenatntcd  Ibat 
tli«  nddilion  of  a  atrann;  acid  to  a  pseu<l<>(icidfla1t  litinrtiti-^tlivp^iTudn- 
acid,  and  Hint  it  ia  slowly  coinei'tcd  into  tbd  noTniid  iiiudilu^ittJOii. 
IiiVL-rst-ly,  Itio  addition  of  an  i^iulYaloot  quantity  of  caustic  alkali  Co 
tbe  iiorniiil  mndincailon  nwiUts  in  its  )^a(Iu:d  u«utra1ixaUon.  This 
'*8low  nvutralifflition"  ia  a  characteristic  of  lh«  pseudo^aoids. 

Aiiotbrr  crlixrlnn  for  tbein  is  illustrated  by  dtiiitro«thai]e,  witldi, 
aftor  boing  litK-riitcd  from  its  sodium  salt  in  accordnoca  with,  ibo 
equation 

taoiiinlLroriliftuii 
is  BO  rapidly  converted  into  the  notxanl  compound,  CHi-CH<jfQ'i 

lluit  a  cbnng«  il]  lltu  i-leotric  conductivity  of  ibo  solution  can  scarcely 
boobocrved  even  at  0*.  Tlie  cieutrat  refiotion  of  tl»onlkiili-derlvativ<« 
of  tho  nonconducting  or  weiikly-condiicling  hydnigcn  comiKMind 
DDTcrtlicItrss  iiidicatei)  the  «j;intvuco  of  a  |«eiido-acid.  An  acid  which 
,  i>  BO  weali  that  its  solution  is  a  bud  ooiiductor  of  cleclriclly.  yields 


368  ORGMMC  CHEMISTRY. 

AlluU-«dU  which  ond«rgo  ttroDji  hrdrolftk  dusocklion.  and  th»r«- 
for«  hate  astrongljr  allcaliiw  nnctioii  ("Inorguiio  Cbemutry,*'  tU|. 
Soob  a  •nbstHDW  as  »oiiliodttiitroetliaue,  whow  &oluti<ra  is  uot  alkalmi;, 
m»l  therefore  be  derived  from  an  acid  oiher  than  (linitroeiliaiip,  »iiu« 
thi«  MbMance  hat  a  MMitral  reaction  aod  1«  a  ooo-coiidQCtor  ia  aquo- 
oos  eolutioo. 

Among  the  other  raethoOa  of  det«otiDg  pModo-aeids,  (be  adding  oa 
or  ammonia  maybe  [DentJoneO.  A  irDeacld.  w  ban  dlaaolTed  in  banzda* 
or«DO(h«r  bydrocaTboo,  oombiDcs  tnttaaianMiuly  ihth  dry  aounonil 
to  form  aa  inaolabte  ammoDiuiu  salt.  A  pseudo-mdd.  on  Ibecootniry, 
either  does  not  add  oa  Ntli,  oroaly»Iovrlr,  being  ioth«lattvrca&o  firat 
eooTerted  into  a  true  acid. 


TIL   MOnOAHIHO-COIIPOnilSfl. 

282.  The  amino-compounds  of  the  aromatic  M'rips,  with  the 
NH,-group  attach«l  to  the  ring,  are  almost  exclusively  obtaiiiml  by 
reduction  of  the  cnrrrapoDciing  nitro-compoiinds.  Ttiis  is  effected 
by  the  action  of  tin  and  hydrochloric  acid,  irou-fiUiigs  and  acetic  or 
hydrochloric  acUl,  or  by  other  rea^cots.  On  the  manufacturiag 
Bcalo  it  te  ii£uaJ  to  employ  iron-filings  aiid  liydroclUuric  acid. 

Amines  can  be  obtained  from  phettoU  by  heating  tJicm  at  300'^ 
with  ammonium  zinc  chloride. 

The  aromatic  aminos  are  colourless  liquids  of  high  boiling-point, 
or  sTilids,  and  have  a  rharacterislic  odour.  With  water,  the  ali- 
phatic amines  form  stronger  bases  than  ammotiia,  but  the  aqueous 
siihitiuiu)  of  the  aromatic  amines  pasaess  only  weakly  l>a.'uc  pro- 
perties; thus,  they  do  nut  turn  red  litmus  blue,  aiul  !iearc(>ly  con- 
duct an  electric  ciirreut.  The  aromatic  amines  yield  <ialt«i,  how- 
ever, althoufrh  tiiese  have  an  acid  reaction  in  solution,  on  account 
of  partial  liydrolyas.  The  ne|:fttive  cliaraeterof  the  phcnyl-group, 
already  alluded  to  in  coitRecti<m  nith  phenol  (376),  coo^dcrably 
modifies  the  nBtun>  of  the  ainido-gnmp ;  the  liehaviour  of  diphenyl- 
aiiiine  and  t riphenylamine  in  particular  betrajn  this  influence. 
With  Htrong  acid:i  the  former  can  yiirld  ."uilta,  which,  however,  aro 
completely  hydrolyzcd  by  addition  of  much  water;  the  second  no 
loRKcr  uiiitoj^  with  acids. 

Substitution  of  the  amido-p^iup  for  hydrogen  produce*  the  e&mo 
effect  u]K)n  the  benzene-nucleus  as  substitution  of  the  hydroxyl- 
grotip  for  hydrogen,  niakinjE  the  rest  of  the  hydmpen  atoms  of 
the  nucleus  much  more  easily  replaced;    thus,  aniline  is  mUilj 


MOftO^MINO-  COMPOUNDS. 


3*9 


converted  by  bn)raiiie-waler  into  tribroinoaniline.    Moreover,  the 
amines  aro  much  niura  reatlUy  oidJized  tliari  the  hyJruoarbons. 

By  uicaiis  of  an  alkyl  li&JiUi',  the  Iiydrogeo  atoma  iu  l]i«  aiuiito- 
group  of  the  primary  aromatic  ainiiies,  like  those  ui  the  aintdo- 
group  of  the  primary  aliplmtic  amines,  can  be  replaced  by  an  alkyl- 
group: 

C,H,NH,  +  CH.I  -  C,H.-NH(CH,).HI. 

Secondary  and  lerliary  bases  and  also  strongly  basic  quaternau^ 
armmmiuin  basos,  sucli  as  C*K6'N{CH,),-0H,  are  known. 

The  anilitit-a  are  ilL-rivativos  of  aniline.  C'bHj-NHi.  and  its  horao- 
logues;  lliey  ore  acid  amides,  in  which  one  aniido-hydrogen  atom 
is  replaced  by  a  phenyl-group.  AtxianUidc.  CaHcNH-COCH^ 
emplnywl  att  a  fobrifuge  under  the  name  "  aiilifpbrine."  is  a  lypp  of 
these  compcmnds.  The  aiiiliili'!i  aiv  prwluetd  by  boiling  aniline 
with  the  correspondiog  aoid;  acetaiiUide  ijs  obtain«l  by  heating 
aniline  with  glacial  acetic  acid: 


CH^NHIH  +  HUlOC-CH,  =  C3fNH-C0CH,  +  Hp. 


UEKHTHirTKiN  found  tbat  the  velocity  of  formation  of  acetaDllidn 
it  much  Icse  (or  an  vxc^tta  of  aniline  tlixn  for  an  excess  of  glndfil 
aoeUo  noid,  nlthougti  uu  llidoriitical  ijrouiiils  the  velouicy  at  rorciutioTi 
ebottldbe  lbc»in)«  in  both  case*;  for  at  each  moment  ft  should  bo  pro- 
portional to  the  i^rocliicc  of  the  concent  nit  iodh  uf  (lie  glacial  acclio 
aoid  (v)  and  of  tho  anilino  (■/),  bonig  thcpufore  expressed  by 

jf  =  A-oy, 
in  which  k  is  coii&tant, 

Tiio  (li fferetit-a  between  liieory  and  eiperiment  can  be  Tarioosljr 
exitlalaed;  for  iiiaiance,  on  tho  ground  that  tbci  reaction  hi  the  two 
oases  Inkea  place  lit  dilforetit  media.  Tliu  important  isaueQce  of  Ike 
medium  liaa  been  mentioned  (Tl), 

Aldehydes  react  xrith  aromatic  amines  with  elimiiiatiou  of  wat«r : 


ronuAldi-tifiln 


M»thjton«<llphon]rlilliiniln« 


Primary  aromatic  aminfs  show  the  rarhylamino  iraetion;  with 
nitrous  acid  they  yield  diazonium  compounds  (302). 


283.  Aniline  was  first  obtained  by  the  dr>'  dintillation  of  indigo 
{anil) ;  hence  il»  name  II  is  manufacturrti  by  the  action  of  hydro- 
chloric acid  and  iron-filings  on  nitMKnaene  conlainwl  in  a  cost^iroD 
cylinder  fitted  with  a  slirring-apparataB : 

C^Np,  +  3I''8  +  6UC1  =  C,H,M[,  +  2H,0  +  SFeCl,. 


IS  remarkable  that  in  this  profi'ss  only  about  one-fortieth  of  the 
hydrocldoric  aciil  required  by  the  equation  is  needed  for  the  reduc- 
tion. This  is  probably  because  iron-filtnga  and  watpr  are  able  to 
|i»,»eductJou  in  presence  of  fermu*!  chloride.  Lime  ia  added 
MM  W  tbe  r&duction  is  complete,  and  the  aniline  is  distillod  with 
steam. 

AniliiH- 18  altio  obtained  by  thf  fk'rtPo-r«luc1ion  of  niiro-b«n;^ 
t'M  (292). 

Aniline  is  a  colourless  liquid,  anil,  unless  perfectly  pure,  turns 
brown  in  Uie  air,  the  culoitr  clianKe  being  probably  due  to  the  prcs- 
oDce  of  traceii  of  a\ilphiir  eompountls.  It  is  only  slightly  st^ublo  in 
water;  it  boils  at  ISO'*,  and  has  a  Hpccific  gravity  of  1*024  at  1G°.  It 
eau  be  reeonvertod  into  nitroljfnzfue  by  ctTlain  oxidizinp-ageiils, 
variouti  intern letllalt-  product*,  sueh  as  nilrowilieiizeiie,  G,H,>NO, 
being  obtained.  Anilijie  midergoes  oxidation  eoniewhat  readily; 
lh«  co[iip<iundr<  tiitJi<  ijbtaiiicd  will  be  described  luicr  (389). 

An  aqueous  solution  of  free  aniline  gives  a  deep-violet  colouration 
n*ith  blea<;hLng-[Kiwder  solution;  an  aniline  Kalt  in  acid  solution  is 
colrtun-d  tlar](-greeri  to  blnek  by  pntjissiiini  dichnimate.  These 
two  n:&(aion.s,  and  that  with  wixhI  (23S),  M?rve  a»  U-sis  for  ftitiline. 
The  bteucliiug-puwdcr  reaction  U  particularly  delicate. 


Homologues  of  AnIUae. 

Ortho'toluidine  and  pftra-^^/uidllM,  CH,-C»H,'?«I1^  arc  formed 
by  the  reduetion  of  the  corresimnding  nitnvcompounds;  the  <>rtho~ 
compound  is  a  liquid,  li.P.  199-4*;  the  pnra-compound  Is  solid, 
-M.P.  42-5*.  The  different  solubilities  of  their  oxalic-acid  salts 
are  made  use  of  to  separate  them. 


!  HOMOLOCUES  OF  ANIUNE  AND  SECONDARY  AMINES,     37 1 

'■m-TfAuidine  can  only  be'obtaiaed  indirectly.  p-Tolaidine  is  con- 
Terted  into  its  acetyl-derivatire,  0Hi-0(H4-NH0iHi0,  which  on 
nitration  yields 

0.0. 

NHC,H,0 

The  acetyl-gronp  in  this  compoand  is  split  off  by  boiling  with  hydro- 
chloric acid,  after  which  the  amido-gronp  is  eliminated  by  the  method 
described  in  SOS,  3.  On  redaction,  the  m-nitrotolaene  thas  formed 
yields  m-tolnidine. 

The  monoamino-derivfltives  of  the  xylenes  are  called  xylidines. 
Six  isomers  are  possible,  due  to  differences  in  the  relative 
positions  of  the  methyi-groups  and  the  amido-group  in  the 
ring.  Some  of  the  toluidines  and  the  xylidines  are  employed  in 
making  aniline  dyes,  and  are,  therefore,  manufactured  in  large 
quantities. 

Secondary  Anunes. 

284.  Dipkenylamine,  CgHs-NH-C,Hn  is  a  type  of  the  true 
secondary  aromatic  amines.  They  arc  formed  by  heating  the 
hydrochlorides  of  the  primary  amines  with  the  free  amines: 


C,H,|NH,-HC1  +  H|HX-C,H,  =  NH,a  +  HN(C,H,),. 

Diphenylamine  can  also  be  obtained  by  the  action  of  bromobenzene 
on  potassium  anilide,  C,Hj  ■  NHK. 

Diphenylamine  is  a  solid,  M.P.  54°;  it  has  an  agreeable  odour, 
resembling  that  of  some  flowers. 

Diphenylamine  is  a  very  sensitive  reagent  for  the  detection  of 
nitric  acid,  liquids  containing  which  produce  a  deep-blue  colonr  with 
its  solution  in  concentrated  sulphuric  acid.  This  reaction  can  only 
be  nsed  to  detect  nitric  acid  in  the  absence  of  other  oxidiziug-sub- 
stances,  such  as  bromine-water,  permanganate,  etc.,  with  many  of 
which  diphenylamine  also  gives  a  blue  colouration. 

The  method  of  formation  of  the  mixed  aromatic-fatty  amines, 
such  as  methykmiline,  C^-NH-CH,,  has  been  already  indicated 


TERTIARY  /iMiNES. 


373 


it  of  hydrochloric-acid  gas,  tiie  alkyi-proups  are  split  off,  with 
fonnatioD  of  aniline  and  alkyl  chloridL-s.  Whon  the  hydrocfilorides 
of  the  alkyl- anilines  are  sirongly  heated,  the  alkyl-groups  linked  to 
nitrogen  are  transferred  to  the  benzene-ring;  this  can  be  explained 
by  assitmiiig  that  deuompoeitiou  iutu  alkyl  chloride  and  aiuliuc-  first 
laln'i?  filare  as  just  described: 

1,  c^/Nii(c,iij)na  =  c,n,-NH,,+  c,n^. 

This  is  tlifii  foIlnwKd  by  tlie  rcaclioo  indicated  in  equation  II: 
I  11.  C,H.-i\H.  +  C,H,C]  =  CeH.<^J,^'fjp,- 

^1      Tliese  roaetjons  explain  the  formation  of  the  hydrochInri<lp  of 
^»  jKtoluidine,  by  the  interjicl km  of  metliyl  alcohol  and  atiiliai!  Iiydro- 
rhloride  at  a  high  t^'nippriiture.     lly  this  process  it  is  possible  to 
obtain  even  ■pmlainrlhylatninohcnzcne,  C„((;Hj)jNH,. 
^_       Uimethylaniliue  and  other  dialkyl-anilines  possess  the  remarlt- 
Hjkblo  property  of  having  their  /vH-atom  rcwliiy  replaceable  by  differ- 
ent grouiJs,     Thus,  dimethylaniline  reacts  readily  with  nitroii»  at^id, 


with  fnrtnation  of  nitrogodimethytaniline,  ( )JJ 


NCCH,),,  eflfcetcd 


by  the  addition  of  potassium  nitrite  to  the  solution  of  the  tertiary 
base  ill  liydroehlorir'  acid.  This  iiitros<M;oinpound  eryslalliM's 
in  well-defiiied  leases  of  a  fine  green  colour.  It  melts  at  85", 
and  yields  a  hydrnehlnride  crystallising  in  yellow  needk*.  On 
oxidation  with  pntasaiiini  ^wrniianganate,  the  nitropo-group  is  con- 
■Srertcd  into  a  iiitro-group,  with  formation  of  i^nitr&dimdkylaniline. 


C  IL <^<^^i'>  ^ 


4* 


On  boiling  w-ith  caustic  soda,  the  amido-group  of  nitrosodi- 
methylanihne  is  rompli^toly  split  off,  with  formation  of  dimcthyl- 
imuuc  and  nitruHuphenol: 


k 


C^.<Xo"»''  +  H,0  -  C,H,<5^^  HN(CH,),. 


NltnHKililielinl. 


This  reaction  ia  employed  in  the  preparation  of  pure  dimethyl- 
I  amine  (72). 


374 


ORGANIC  CHEMISTRY, 


The  i^liydrogca  atom  of  tlimethylarulinc  can  react  with  sub- 
stances other  tluLD  nitrous  acid;  thus,  aldehydce  readily  yield  a 
condensation-product ; 


C|,H,-CH 


Q  +  hIc&K!;-  C.H.-CH[C^.N(CH^J.. 


The  constitution  of  this  cnmpound  ui  deduced  from  ita  relation  to  (rv 
phcnrjlmclhatif.  ('H(C,Ur,),  (366).  With  dimcthvlaiiilinc,  carbonyl 
chloride  yields  a  p-derivativc  of  bcnzophcnonc,  C,Ht'CO'C,H,: 


\ 


Cl  +  H 


Cl  +  H 


C:,H/N(CH,),      ./C,H,-N(CHO, 

=  CO  ,  +  2Ha 

C,H,  •  N(CH.),       \C„H,  •  N(CHO, 


When  diniethylaniliii(>,  and  ottier  analogous  tertiary*  amines,  are 
treated  with  hydrogen  pen)xide  al  ftO*-70°,  ihey  yield  compounds 

C,H^N(CH,)^ 
Bueh  as  dimetkijlaniline  oxide,  t  whom  constitution 

O 
follows  from  its  being  remlily  reducible  to  dimothylanilioo. 


CLaatemary  Bases. 

286.  Quaternary'  bases  are  formed  by  the  addition  of  alkyl 
hfllidcs  to  the  tertiary  arotnatic-fntty  amines,  artd  treatment  of  the 
salts  thus  funned  ftitli  moist  siKrr  iixidp.  These  subelanccs  are 
strong  bases.  On  heating,  they  split  up  into  an  alcohol  and  a 
tertiary  amine,  wherein  they  differ  from  the  aliphatic  animooium 
base*  (73). 

AUeiDjits  have  been  made  to  Bpht  up  the  qunternary  Rmmoiiiafo 
hases  con  taininft  four  diflsimiUriirroiips  into  optically  «ctivfl  00  iii|>oiK!nt«. 
These  ooiupounds  of  the  lypo  SR,R,R,R.X,  fii  which  X  in  aii  aoul- 
rtuliclt',  vruukl  ovrc  their  optical  ncLivity  to  ibv  prEsonco  uf  na  asym- 
melric  nit)'0!fen  atom.  TliU  tlLK!oiup(>SLliuti  hiu  Iwi.'n  n-cently  effected 
by  Pope.     Betut/tphevt/lailj/imeihj/kimniotiium  hydroxide. 


B01T(0n,C.H.)<C.lI.)(CH.)(CU.). 


Q^ytTEHN^RY  BASES  AND  BENZYLAMINE. 


375 


mUM  vlth  the  strongly  opticRtlj  itctlro  tJ.cnmphoR«ii]|)liai)[o  Hvid; 
tlie  salt  obtniniMt  in  fnictioi»illy  oryelallizLMJ  from  ncclonv,  a  solvent 
wkiob  is  not  so  likely  Lo  dmompose  it  into  nlcohol  urid  tertiar/  \M&e  im 
&oIvfinl8  containing  n  liydrosyl-groiip.  By  this  mejiiia  tlie  bane  can  li« 
Bplit  up  inio  lis  dextro-rotatory  »nd  l»vo-rotalory  comixment*  A 
ooni])lclu  <lc uiuii.it rat iuu  of  lh»  jiosiLioii  tiiid  direotiou  of  the  bonds  of 
til*  |i«HlAviiltM]t  uiirogpti  utoiii  \m*  ixil  yd  been  glvt>ii. 

That  certain  tcrtinry  amines  poaseaa  tho  property  of  forming 
addition -prod  nets  nitli  alkyl  Imlidps,  vrbilct  others  do  not,  is  probably 
alao  espltcnltlo  on  AtcreochGiDtcal  grounds.  TtiuR,  to  account  for  tfao 
fuel  that,  nithniigh  lri|)ih«oyl amine  niid  diphenylnielhylaniiiie  do  nut 
form  aJditiuu-pruducta  willi  methyl  lodiiW,  Iribt^uzytuiuiuc  ia  capable 
of  doing  BO,  It  is  asKDiuoil  Ibat  the  plionyl-groujtit  of  Mto  liro  former 
compouuds  arc  so  sttuatoil  iu  rclnCiou  to  the  nitrugon  atom  tbal  no 
spara  is  k'ft  for  CIlil  to  approach  it.  If,  liowover,  ibo  tliri'o  benzene. 
nuclei  of  tripheny limine  are  removed  to  a  distance  from  Ibe  N'Sluiu 
by  the  iolroduction  of  three  CTTi-groups.  na  in  tribenzytamine,  suffi- 
ei«fit  apace  ia  left  for  CH.I  to  approach  th«  N-atom. 

Benzylamine.  C,HjCH,NH,. 

287.  Bemylamine  is  a  type  of  the  amines  with  Nil,  in  tbo 
aadc-chaiti.  It  can  be  ohtainnJ  by  the  varinus  tncthfHls  einploycil 
in  the  preparation  nf  aliphatic  amines,  surh  as  the  action  of  benzyl 
chloride  upon  ammonia,  by  which  dttn-Tutjlamine  and  iribemytcmiM 
are  alsu  ftirnu-fi;  uil'lition  of  hyilnjgcn  to  bcnzonilrjle,  C,Hj"CX; 
reduction  of  phenylnitromothftnc,  CoHjCHj'XO,;  otc.  Its  iiiPthoilA 
of  fomiatioii  and  its  properties  prove  that  bonxylamine  belongs  lo 
the  primary  ariincs  of  the  fatty  scries:  thus,  it  does  not  yiold  lUa- 
zonium  compounds;  and  itsaqucousAolution  has  a  strongly  alkaline 
reaetion,  proving  it  to  be  a  much  stronger  base  than  aniline,  iu 
which  the  NH,-group  is  under  the  direct  influence  uf  the  phcnyl- 
gruup. 

neoxylaniin?  Is  a  li<[uid  of  ainmoniacal  odour;  it  boils  at  iSo^, 
is  volatile  with  steam,  and  has  a  specific  gravity  of  0'9S3  at  Iff^. 
it  abiiiorbs  c&rbou  dio.iiUc  from  the  air. 


Culioalc  Acid  D«TlvatiT«i  of  Aniline. 

nt.  Only  a  tow  of  t1>e  numerous  compounds  of  this  claa  can  be 
described  here,  rfinisilurerinvir.  CHtNU-UO-OCMI..  is  formed  by 
tb«  iaterattioa  of  chlorocnrbonic  ester  and  nnilino  ;  it  is  a  solid,  nod 
iiwlt4  ni  52'.     Wbea  distilled  with  phosphorus  pentoiide,  ii  yields 


> 


J7fi 


ORGANIC  CHEMISTRY. 


phtngl  isocyanate,  CiHt-KiOiO,  a  ooloarlen  liquid  prodoetlir*  of 
tMn,  which  boils  at  166*.  It  b  aometimes  nnployed  in  tti«  dctcctioa 
oF  OII-groiiCM  or  Kllt-groap*  in  oompounds,  Riiics  Id  pivsmee  of 
thoM,  subfttituted  urothuiw  fend  ur*a  rospectivcl)'  an  obtained.  VHh 
wXLet  it  };ieldaEjiD[ni*trical(f//iAr»y^f(rM,  CO(NU-C*Q»}i,  kcryttalUne 
•ub»laDC«  melting  at  SSV  <»>>. 

Salphor  DeriTStirei  of  Aniljoe. 

Snlphiir  dorJTstlres  of  Anilino,  slmlliu-  to  tho  eomiMilllda  deectibed 
in  94ft  HD(1  lU,  are  also  knoKn.  One  of  tboM  is  phenyl  muMtard-oS, 
C,n^-N:0:S,  which  baite  at  3S2*.  It  ia  obtained  b;  boiling  cJr;i/Wn^- 
tfihurea,  CS(^\l-CJti)t,  ii'iih  hydrochlorio  nciil :  dlphenyllhloarea 
itaeK  id  formed  by  healing  carbon  dlinlphidc  with  anilioe: 


Tin.    INTEaiCEDIATE  PBODTTOTS   DT  THE   BEDTCTIOir  OF  ABOMATIO 
niTBO-COMPOOHDB. 

289.  On  reduction,  the  iiitro-conipoimds  of  the  aliphatic  series 
yield  amines  directly,  from  wIiirK  the  alkyl-gmupa  an-  qilit  off  Iw 
oxidation;  fthylamine,  for  cxamplo,  B  eonvcrtod  into  acetic  acid 
and  aminonia.  In  tho  aromatic  K«>ri<«,  on  the  nther  hand,  iot«rm(s 
tliatt>  product*  fan  Ix?  obtained  buth  m  the  reduction  of  jiitrtMjom- 
potmdf^,  and  somclimns  alsn  iii  thr  nxitlation  of  thr  amines.  Only 
tlie  compoundu  drrivrd  from  nitrobi-nzrnn  and  anilijie  will  be 
described  here,  ulthough  umucrous  substitution-products  of  tlie 
same  type  arc  kno»-n. 

In  acid  solution,  the  nitro-compounds  are  din?ctly  reduced  to 
the  corresponding  arainoderivativis,  but  in  alkaline  solution  yield 
subfltanoes  containing  two  bcnzene-rcinducs.  Nitrobenzene  yields 
in  succcsiiun 


1.  Nitro-compmmd 

2.  Awjxy-compound 

3.  Axo-compound 

4.  Bydraio-cumpoimd 

5.  Amino-Gom  pound 


C,H,-N=NCJI, 
C„H,NH— NHCA 


390.  AtOTjtbentene  la  obtained  b;  boiling  Qitrobentens  witb 
alooboUe  potash,  and  ii  also  formed  in  th*  ozldaifon  of  aniline  vrilh 
potaaaium  pernunganale  In  aloohollo  solution.    It  forms  ligfat-jellow 


REDUCTIOK-PRODUCTS  OF  NITROBBSZENB. 


377 


«78Ul8  melting  nl  38*.     When  vartned  with  coDcenirated  sulphuric 
Bsid,  it  is  tmnsforaMid  into  hytlr<fX]/tu<Aent«n« : 


CH.X- — N.CIl, 


.c,n.-\=ycMi.-oH. 

1  l]rdnri)'*sc>beii»Dii 


It  is  readil}-  attacked  by  vurioiu  reduciDg-ageaU. 

S9t.  Azobcnzcne,  C^Hj'NtN-CjHg,  IS  ffirmed  bythe  reduction  of 
nitrobfnzcni*  with  a  solution  of  stannous  chloriclp  in  excess  of  caustic 
potash,  and  also  by  dUtilling  azoxybeiizene  vritb  iron-filings.  It 
is  prodti»'<l  along  'vvHth  asoxybenzciic  by  the  oxidation  of  auUine 
with  potiissiiim  pprnmnganatp. 

Azoboname  forms  wellnlcfined,  orangi-n'd  cryslabt.  niplting  at 
66",  and  boiling  without  dfcomptwitiun  at  295".  It  is  n  very  stable 
compound,  ami  is  insnlubkr  iu  water.  Its  ci>i;siitutioii  follows 
from  its  yieldiof;  aniline  on  rttluction. 

Jiydrazohemenc,  C„H»'NH— NH  ■C,Hj.  is  fonned  by  the  action 
of  zinff-tlust   and    alcohoiic   pota.*h   upon    azobonzenc    or  nilro- 
benaono.     It  is  a  coiourlass,  rry.st«llin(!  siibstancf ,  and  melts  at  126°. 
Strong  reduring-agents  convert  it  into  aniline;  on  the  other  hand, 
I  it  is  reailily  oxidizcnl  to  azobenzene,  this  transformation  being 

^B    i^Owly  effected  by  atmospheric  oxygen.     It  is  also  oxidised  to  the 
^^    aeo-compound  by  ftrric  cldoride. 

I  The  most  characteristic  reat^iion  of  hydrazobeiizcno  is  its  con- 

I  version  into  benzidine,  whereby  the  benzeu^nuelei  are,  as  it  were, 

I  turaed  end  for  «nd ;  this  is  eflFected  by  the  action  of  strong  acids : 

f  Thi 

I  ofb 

L  *^ 
■     1 


^O^XH-Nh/o^  -  H^-C,H.-C,H,NH,. 


tl  jrdnuo  ht-nvmn 


Bsutdiav 


That  a  dinminodiphenyl  is  thus  formed  is  pmveil  by  th«  conversion 
of  benzidine  into  diphcnyl,  C^Hj-CgH^.  The  aniido-g.xiups  occupy 
the  jxiro-po^tions : 

'      '  '      '  >NH,. 


By  reducing  azobenzene  in  acid  solution,  benzi4line  is  formed 
directly.  It  is  characterized  by  the  sparing  solubility  iu  cold  watar 
o(  its  sulphate. 


■ai 


J78  ORGANIC  CHEMISTRY. 

The  amido-fcroups  iit  bcDxidiiis  Arc  proved  in  varioiia  mifa  to 
oceupy  Itifi  paro-po«ilion:  for  vximiple.  a  hjdraiobeiiMno  whose 
p-hydKigvii  atoms  tiATe  be«n  aubstituled  «nnnot  be  converted  into 
bensiiliiiH.  lii  twrUin  liislancw  oompouiidB  of  ibis  kind  can  umlfr|^ 
a  remitrknblQ  intramolGGvlAr  trAQiformalion,  known  aa  the  Mntiflin»- 
trAnsronnaLioii.  forming  cIvriratiToe  of  dipheDylamino  by  the  tDmintr 
of  ouly  one  of  tb«  beozeDO-DUClci : 


p-AonUmiclobjrilnuDbeiunw 


p-A  (11  III  ciphanjrl'p-aociani  htt^ 
piitnjtjBiInt 


Electro- redaction  of  Nltro-compon&ds. 

292.  Thi-n*  is  reason  lo  believe  that  in  tlie  future  eloctric 
raetlKxIs  will  bp  uswl  more  and  more,  for  the  electric  current  affords 
a  means  nf  varying  the  pressiire  and  cnrcentration  of  the  c«;>m- 
jiuunds  taking  part  iii  reactions  in  the  preparation  of  organic 
compound",  which  is  not  othenvTse  attainable,  Hyitsaid  it  is  poe- 
sihle  t"  t'Pfeel  ni?w  syiilheaci)  or  to  inifirove  those  alrwidy  known. 
An  cxplaimlion  of  the  mode  of  altering  this  pn-ssuro  and  conceutra- 
tioii  is  uc'cessary  liere. 

It  wfta  8tat4.ti  (258)  tliut  alteration  in  the  difference  of  potential 
of  llie  electnides  causiw  coiiaiderahlo  variation  Ju  Ihc  pr««ure  at 
which  the  dischargtsj  ions  leave  the  solution.  In  rwluction- 
|)mppR'«?M  till-  Mime  effect  is  attain<Ki  by  using  riiffercnt  reducing- 
agent«.  ^Tion  a  fotnpmnid  yiflds  a  neries  of  intermediate  products 
on  In'atniciit  with  different  reiiueing-agpnts  of  iiiereasing  strength, 
this  can  abo  In-  rffccted  by  incrL-asiiig  the  potential  at  the  cathode, 
where  h>'ilrufien  its  evolved. 

Hcgarding  variation  m  the  concentration,  it  must  be  remem- 
bered that  the  electrolytic  i)mceB8  takes  place  only  in  the  immediate 
neighhourluHtd  of  the  eleelrodeji.  When  the  surface-area  of  thoi 
clpctrmles  is  alten-d,  the  strength  of  the  current  remaining  tlie  same, 
the  number  of  ions  discharged  at  unit  surface  varies  ia  direct'  pro- 
I)ortion;  it  is  therefore  powsilde,  by  scleeting  niiitable  eleetrodcs,  to 
cause  the  concentration  of  the  iona  discharged  at  them  to  ^-ary 
within  wide  limits.  The  "strength"  of  the  reduciiig-ftgciit  depends 
upon  the  (liffenmce  of  potential,  but  its  eoncenlrution  is  controUe<I 
by  the  density  of  the  current  (1$9).    In   reactions  in  which  the 


ELECTRO  RBOUCTlOfi  OP  ftlTRO-COMPOUNDS. 


37S 


diacharged  ions  must  act  on  one  another,  as  la  the  synthesis  of 
dibasic  acids  (loe.  cU.),  a  current  of  higli  deiimty  \b  necessary;  oo 
liie  other  hand,  in  recluctiaus  which  iiuist  take  place  a*)  far  as  pos- 
sible at  all  jiartK  nf  the  liqiiiii,  largo  cathodes,  which  giveacurretiiof 
small  «h;n!iily,  muat  be  used. 

Oa  reduction,  the  Ditro-eooi pounds  ultimately  yield  ainines,  but 
a  numl)fr  nf  iitti-nnLtdiatc!  rtituction-products  can  be  isolated.  For 
this  reason  the  electro-rpcliiotion  of  nitrobenaene  and  iw  derivatives 
is  of  both  thoorpticHl  and  practiejil  iiii|»)rtanre;  it  has  been  found 
posable  to  gi\'e  a  (-(iinptete  and  saliefactoty  explanation  of  the 
mechanism  r»f  this  i)nHTe»i. 

A  distinction  must  be  drawn  bctwrarn  primary-  and  sccondaij" 
redurtion-pnKhicts.     Tlii:  primary  pr<K.'cs8  is 


MLrObFMU'lir 


(•„Hj-N"HOH 

PtipnylhrdrnTjI. 


Th«  |ir«-soii<w  of  nilro«obeiiu}no  c»n  tic  (l«tecut(l  liy  tbo  addition 
of  hydnuylnmiiio  to  the  liqwicl,  with  which  it  ruactB  with  loss  of 
one  molecule  uf  vnler,  and  formnlion  of  iJiitioiiium  hydroxide, 
C^llfXiOH;  on  lidding  •t-na|ililli(il,  atiii»i-dv€  is  priKliicod  (SSO).  Tlio 
fortniiiion  of  ptioiiylliyilroiylnniiiio  aim  lin  provnl  by  nddinf;  benznU 
dehjdv,  n'icli  which  it  yields  bouzylidciici'liuiiyniydroxyluniiue: 

C.Ht-NHOH  +  <X;ir  (:,H,=  ll,0  +  C.HjN OH-C.Hi. 

BiBiiuildrbyilo  v.  / 

On  rapid  reduction  of  nitrobenzene  disftolvcd  in  nioderately  con- 
centrated stdphime  acid,  with  nddition  of  alcohol  to  increase  the 
solubility,  the  primary  prtn'<'ii!i  just  dnscriboii  takes  platre,  about 
90  per  cent,  of  the  tlworetiral  yield  of  aniline  Iwlng  obtaintil.  In  a 
strongly  acid  »tiliition,  however,  the  phcnylhydroxylaniinc  is  very 
quickly  converted  into  ;>-anunopiienol : 

c,ii,xHou  -  Hoc,n,-\n,. 

This  sulwtjince  is  not  further  peducefl.  Sinee  phenylliyclroxylamine 
undergoes  the  same  tnin.sforniatinn,  thniiph  niiieli  more  slowly,  in 
presence  of  more  dilute  acid,  it  is  evident  that  in  the  latter  case 
the  theoretical  jncld  of  aniline  cannot  be  quilt-  ohtained,  even  when 
the  velneity  nfreiluction  i^■  ureal. 

Jn  alcoholic-alkaline  solution  the  electro-reduction  of  nitro* 
beiixeno  i*  accompanied  by  two  secondary  proccssca. 

I.  NitrawticnRcne  reacts  with  phenylhydroxylamine,  yielding 
Azoxybeniene: 


3So 


ORGANIC  CHEMISTRY. 


C^,NHOH  +  C^,NO 


C„H,N NC^  +  H^. 

0 


In  preBeoce  of  alkali  this  reaction  prciccctU  ituich  nton*  quirkly  than 
thp  further  rciluctian  of  phciiylbytlroxvlaimni'.  !hj  that  only  small 
quantilios  ■>f  aniline  arc  formed,  and  higlitT  ivduotjon-prwluots 
of  axoxyhcnzpnc,  <'hiof  ainong  thiwe  being  hyilraznljpnzene,  obtained 
as  the  main  part  of  thp  yield. 

2.  HytirajujlH-nzrni!  is  atlackcil  by  IHr  unreduced  nitrnljenzene 
with  fnniiatiiJii  of  azolH^nwne  and  azoxy benzene : 

3C,H,NHNHC,H,  +  2CeH,N0,  -  3C,H,  ■  N :  N  "CaH,  + 
+  C,H»X NC,H,  +  3H,0. 

O 

Since  hydraitnbenzpnc  in  alkaline  solution  is  qtiickly  osicliEcd  by 
atnwjspherii;  oxygun  to  azobeiizcue,  the  yidd  of  the  latter  is  very 
BOtxi. 

A  much  higher  tvnsioii  is  required  at  the  cathode  to  reduce 
hydrasobcnsciie  t<f  aniline,  so  that  in  atkalinr  eulution  the  reduc- 
tion-process ceftsOB  witli  the  production  of  the  former. 

llABEit  has  conibiiifMl  all  tlu^He  jiriniary  and  st'condar>'  reactions 
in  the  followiiig  scheme,  the  VL-nieal  arrows  Indicatiug  primary,  and 
the  oblique  ones  secondary,  reactions: 

,C,H,-NO, 


_C,  H,-  NO 


C,H,N;NCH. 


0 


C.H.-NHOH 


C,iivNH-NH-C,Hj 


Fio.  7a.— RABBn-a  Et-Bcnto-aEoocnoii  Scnua. 


PHOSPHORUS  AND  ARSENIC  DERJ^ATiySS. 


381 


n.    PHEITYL-COMTOITRDB  COSTAUflXO  OTHBB  XUMKKTS 

Phoiphonit  and  Arsenic  Derivatiret. 

S9S.  CoTnponndsof  phoBphoms  and  nnenic  with  ATomatio  fafdnv 
cnrbon:*,  and  hayiiiK  const  hut  ions  similar  to  those  of  the  nitro^com- 
pouniJit,  luo-compniiDdB,  mid  amlno-ROtnpAunJji,  are  linowii. 

Ph»tstUiwiftrn:rnr.  CjlTiPO,,  ciiniitjt  be  obtained  analogoualy  to 
nitrobn'^nEiHio,  by  the  iiiiiM-ncllori  of  mutapltosphorlc  acid  and  bciiwuei. 
It  is  prt'piircd  by  tlic  ncttou  of  phrtiylphaafihinic  acid  upon  ils  cbloridu: 

Qni-POfOIIl,  4.  C,H,.POCI,  =  SCBfPO,  +  8HCL 

PUtiiTlpliiwplilak  CIiI'OtIiI* 

ucId 

It  is  a  whit«,  crystAlliti«,  odonrless  ponder. 

Pheiti/tiihogphiur.  CiITi-PK„  U  obtaliM^  by  HlMWttng  p/wtphfn^t 
chlaridf,  C^Hj-l'dj,  wiih  oloohol,  in  a  current  of  carbon  di«xiil«.  It 
is  a  liquid  witli  ii  vKi-j  iiriictrniirij;  odour.  It  cannot  bo  ubtaioed  hy 
the  nxluetion  of  phoephinohonjcnc. 

Phoaphdmizenf.  C.D'cPiP'C.ni,  is  obtained  by  treating  phenj'l> 
pbospliine  with  ph«epb«nyl  chloride: 

{;[i,  pKvrir,|p-c,u,  =  c.Hj.P:  p.c.ifj  +  sua. 

It  ia  A  pale-yclIow  powder,  insolubie  in  vtaUt,  nicoho),  and  cth«r.    U 
Is  «n«T:gettca)ly  oxidized  by  vreak  tittric  acid,  formiag  photphenylous 

add,    OPr-H     . 

\ou 

Pboaplieuyl  chtoridfl,  0,Hj-PCl„  the  starting-point  in  the  prepara- 
tion of  these  aud  other  aromatio  phosphorus  deriv.iiive»,  can  be  pre- 
pared, aa  caa  Its  homolngUMi,  by  healing;  arrtmnllc  hydivicarlnMis  wlllt 
ptaMpborus  trioblorida  and  nluniiniuni  chloride  under  a  reflux-con- 
deiiscr. 

Ayainohemme.  C^ll^-AsO,,  is  obtalTicd  by  tho  elimination  of  watot* 
trora phenylarsinic  acid.  CgU^- AsOiOll),,  under  tho  intluenoeof  heat. 

Araftwitemem,  OoOj.As :  Aa-0,Hj,  is  formed  by  tho  reduction  of 
pheaj/lartenu:  artde,  CaHg-AsO,  with  pbodphoruua  acid.  It  forms 
yellow  iieodl4>Jt,  and  is  coDVert«d  by  osidation  into  phcnylarslnie  acid 
©.HjAaOcOII),. 

Osa|iarli«n  of  tlw  Aronutlo  DMrlyatlTM  ol  Nlirvgan,  Fboipbonu,  and 

AtkoId. 

861.  Tlie  following  comtwundii  iira  known : 


Klirobenwiia 

„  c<n,po, 

AnIiioljeiiMiiv 


AM>1n*MMII« 

an,.p,i',H, 

Fbo«|il)olirD(ei]e 

anaoobenatDo 


Pbenrlunloe 

C4H..PH, 

ttwarlphoiphloo 


3Sj  organic  CHUMISTRY. 

SaiMtances  In  tlio  flnt  eoluniii  mtty  bo  Inoked  upon  aa  d&rived  from 
Iho  Hiera-atids.  IIONO,.  IIO-PO,.  II<)-AM>,.  by  exehari((o  «f  liyfirosj-l 
for  i>lK<njI.  iiixl  liL-iicu  (.-iLUiiot  linvi*  acidit?  proporl im.  Thfi  nitrngon  Hciil, 
IljSO,,  or  ON(OH)i,  corre)«]i»n<I in^  u>  [ihinspliuric  HCid,  II,PO».  luid 
snenic  aci>d,  II,.V>0,,  is  not  krinv.-ri,  ntiil  Hucurtlingly  iiitrnlXMtZL'nudocs 
not  uaiU)  nitli  wiiU-r,  wliilu  iibosiiliiiiDbonzciiD  nud  nreiaobcoitcnfl  yield 
111*  oorr«!jn>m5iTig  Jioiils,  pbt-njlpliospliinio  aaid,  r,ITj.pO(0n)„  and 
pben>]&raiiiic  ncid,  C,ll«-<VsO(OHi,.  Pliii»|ilioric  nL:iiI  dixfit  not  yield 
P,(\  on  heating;  arsenic  nctd  yttrlils  A«,Oj.  Siinllftrly,  |)li<w]ihino- 
1>eiiEene  oaiiuot  be  obtained  by  liiMtiiii;;  pliciiylplioapliinic  ncid,  itliilfl 
phunjIarsiiiiL'  neid  tg  cniiTorlod  Into  nmimbunzmio  by  litis  Irt-alrnenr. 

Tbc  mcttitxlM  uf  rormation  of  tliv  coiopouada  of  the  second  column 
also  differ  grtnitly  from  oiiu  anollier.  Th^y  aro  all  oulourcd,  (be  moet 
deeply  limed  being  azobcni^uc.  ^'itrobiiiizune  imd  ursLtiobuiuEetie 
yield  aioU-nzi'iie  nnd  arsL'nobfiiizone  on  nHliiclinii;  the  oxygen  of 
phd^hinoWuKt'iiv  is  l«o  firmly  lirikvil  to  phunpljorus  to  itdmit  of  tfaia 
reaction.  On  ri^iiicliuii  vlib  liyilrugvii,  luobL-iizeiivyidtUpbuiiylHiniiitr; 
Cblorlno  cuqvotU  phospbobuoxoDe  Aiid  ArsciiobouBouftiuto  lliocorrc- 
spoiidirig  chlorine  ilerivativex.  C^tlj.pCI,  and  C,II,.AbOI,. 

The  diffuronoo  bofifvpn  llie  two  compauiids  iu  Ibo  last  coluiun  is 
diid  to  ihe  .iiroi))!  aflluny  W'lwcM'n  p1i(»phorui>  nnd  oiyjcen.  Aniline 
ontitiot  be  oxidisud  to  iiii  itcid,  wliile  pheiiylphuopbiiio  is  vury  ruiidily 
cnnverled.  uveii  by  ibc  iwygi-n  of  the  atcttospherc,  Into jpAenyfjiAw*- 
phimti4<uHil,  t',llj.I'0,II,. 

Aromatic  Metallic  Componnds. 

889.  Mcrciirj-,  (in,  li>a<l,  ami  tiingiii^iuin  aw  the  only  metals  which 
yield  nromalic  compuiiniU,  nud  Uivsn  arc  of  much  Xesa  inij)or(ance  (ban 
the  metallic  com  [wunrts  of  ihofnKy  scrips.  M^t^r^-pht-n'/l^  IIg(C,U^„ 
la  obtained  by  (bo  net  ion  of  Bodiiim  auinlgum  upon  hromobenzj^nc.  It 
\i  ory3(al1ine,  and  reaotnblos  lliu  L-orrespoiidiii);  alkyl-derivatives  in  ita 
stability  when  l-xpomhI  !u  air.  WIiqii  ila  vH[K)iir  is  pasnoil  tlin)n>;h  a 
redhftl  lulu?,  it  splits  up  into  mert'urj'  and  di}ili«ayl;  tho  saino  offect 
is  parlinlly  priMlucinl  by  tu  dinLilhition.  M'licn  inercury  n<:iiia(«  ut 
lieatud  wttU  bunzuRC  at  tlU°.  there  nuniUs  pbenylmorciiry  acetiUo, 
CaHfllg-OUC-L'U,,  the  uculiu  add  tsnll  of  tlm  biuw  phenyltQeroury 
hydroiide.  C,H,-Hg-OU. 

Aromatic  maicacatiuu  compounds  arc  referred  to  in  S7S. 


SENZO'lC  ACID  AND  IT9  DEBIVATIYES  AKD  HOMOLOOUES. 


BeDMic  Aoid,  C^Hj-COOH. 

298.  Bcmo'ic   acid   can  be  prepared   by  a  great  variety  of 
methods,  of  which  the  most  irnt">rtaiit  will  bo  iJcscribcd. 

i.  liy  the  oxidatioa  of  aay  arooiatic  hydroearbon  with  a  ade- 
chain: 

C,H,-aH,„.»-.C,HrC0OH. 

Toliifne  is  P])pcially  8cr\'i«eable  for  this  purjjoee,  since  it  can  bo 
readily  obtainwl.  In  Uw  manufacture  of  IieiizoTc  acid,  toluene  is 
not  directly  oxii.U/:fi:l.  but  is  ireal^Hl  at  its  boiling-point  with  clilorine. 
Bcntolrichloritk,  CHj-CCIj,  ia  first  formed,  and  on  heating  with 
water  is  converted  into  benzoic  acid: 


Gl       H 

b       H 


OH 

OH  -  n,o 

OH 


c,H,-cooH  +  ana. 


Benzo5e  acii!  thus  prejjared  often  contains  trace*)  of  efJorob€mo'!e 
ociW,C.H,C1G06h. 

2.  By  the  oxidation  tif  aromatic  alcohols  or  aldehydes,  Huch  as 

benzyl  alcohol,  C,H»-CH,OH,  or  beazttldfhyde,  C^C^Iq;  also  by 

the  oxidation  of  alcohols,  aldehydes,  or  ketones  %vitli  longer  side- 
chains;  in  fact,  from  »11  pompoundH  containing  a  side-chain  wth 
one  carbon  atom  directly  linked  to  the  bonKone-niieieus. 

3.  By  the  irtrofluction  of  the  nit  rile-group  into  the  benzene- 
nucleus,  and  hydrolysis  of  the  iicmonitriic,  CHs'CN,  thus  formed. 

iThe  introduction  of  the  nitrih^-uruup  can  be  cffeetwl  in  two  ways. 
(fl)  By  diawitiziiig  aniline,  and  treating  the  diasonium  salt  with 
potassium  cyniiidc  (308,  5). 
(b)  By   distilling  sodium   benzenesulphonate  with   potassium 
cyanide: 
C,H,-SO,K  +  KCN  =  C,H,-CN  +  IvSO,. 


383 


iu 


ORGANIC  CHEMISTRY. 


A.  By  the  action  of  carbon  dioxide  and  sodium  ou  bromobea- 
«cne,  whereby  sodium  benzoute  is  formed : 

CJI,Br  +  CX),  4-  2Na  =  NaBr  +  CeH,CO,N*a. 

5.  By  the  action  of  varinus  dprivativoR  nf  rarbonic  acid,  instead 
of  carbon  dioxide  lUtelf,  upau  benzene,  subalances  readily  convert- 
ible intu  ln-nKoTn  oriel  bfiiig  fiirtncil. 

(«)  Bcjifittno  and  curbotjyl  L"bi(iridt_'  roaot  topcthrr  in  jirrwnce  of 
aluminium  citloridc,  with  formation  of  benzoyl  chloride,  the  chloride 
of  benzoic  acid,  and  hydiYJchluric  tund: 

C,H,1H  -f  Cfl-COCl  =  C.HjCCX^l  +  HO. 

ll«U(o)  I  vlilurlde 

Benzoyl  ohlnride  is  readily  converted  into  benBOic  acid  bj-  trcht- 
ment  with  water. 

(h)  BcnKiriL-  ami  aluminium  rhinmie  react  with  carbamic 
chlnridf,  Cl'CONH,  (fonntid  by  passing  i;arl>onyt  chloride  over 
h<^atcd  flminonium  chloride),  yielding  bcnzamide,  the  amide  of 
Iwnzoio  acid : 


CjgH  +  al-COXH,  =  C,H,-CONH,  +  HQ. 


(c)  Bromol>enH>ne  is  converted  by  stxlium  and  chloro-carbonic 
ester  into  bcazoTc  ester: 


c.H,Br+a]  cooc,n. 


+ 


Na    Na 


CaH(-CO(")C,H,  +  NaQ  +  XaBr. 


Benzoic  Mid  is  a  oonstituent  of  many  natural  resins  and  balsams, 
such  as  (;uiu-beiizuin  and  Peru  and  Tolu  balaam.  It  in  also  prcacut 
asliippuric:  acid  (200)  in  the  urine  of  horses.  It  was  funnerly  pre- 
pared principally  from  gura-benzom,  from  which  source  the  benzoic 
acid  wvii  Ba  a  m(<<licaiiii>nt  is  HtiU  aometimca  obtAined.  It  is  & 
whit*?  sdUd,  rrj-sijiUizing  in  leaf-like  cryatoln  mchiiiK  at  r21'4*. 
It  sublimes  reailily,  anil  b«iiU  at  2.50";  it  can  l)e  purified  by  dixtilta^ 
tion  with  steam,  with  whicti  ib  is  readily  volatile.  Its  alkali-itulLs 
dissolve  easily  in  water,  while  must  of  those  with  other  bae«a  aro 
only  solubk:  with  diOiculty. 


BENZOIC  ^CID. 


385 


Tb«  solubilit;  curve  ("  InoTj^Dio  CtiomUtir,"  nS)  of  bensolo 
has  been  tbo  subject  of  cnr«fiil  invcstigntion,  en  ACOOUnt  of  itA  in- 
tareBiiag  c!iar«cu>p  (Fig.   78).     The   solubility   inoreaaes  Bomewliat 


O  — ^  «•«■»!«■(  I/O'  no    ULf 

FlO.  78.— SOLfBlUlT  CDKVE    0¥    BttKZOlC    ACTD    IS    WATER. 

mpidly  vrllb  increajw  of  HftniKTftture  ap  to  flO*  (AB).  At  Ihta  tem- 
perature, tbo  oeid  tnclta  bcncalh  tlic  water,  bo  thitt  two  Ii(|ai<]H  roAult; 
one  is  nu  aqiK-ouB  aoltition,  contAining  IIW  of  acid  (point  fl);  tha 
otiier  cuDBiats  itrinci pally  of  ilie  ocid,  of  which  tl  contains  95-kP< 
{point  D).  Above  thia  L«in|M!rnture  an  t-ffect  like  Ibat  dc-seribed  in 
74  is  prudiici^d:  lli«  uiutuiil  Hohibility  of  tb(«e  lajere  in  roproflculcd  ia 
IIm!  i>nrt  JtCt>  of  Uio  cupvu,  of  which  BC  corrofiponda  to  the  »quoou8 
layer,  and  DC  to  ihc  acid  one.  Tiie  coTiiiMisilioii  uf  Oie  iwo  layers  bp- 
«oiiiea  more  and  more  aliko  la  tho  tompdrnturci  riw«,  sinew  the  waler 
diflsolvfls  mom  bensolc  add,  iviid  the  iit'id  mori!  wator:  at  1 16'  tbey  are 
Idcntlcftl  in  composition;  thai  la,  tlie  liquid  baa  again  bocome  licMno* 
geoeouB. 

If  inopu  benzoic  acid  is  ad(l«d  to  thonoidlayoronly.ntflO'.  itisneo- 
essary  to  raise  the  teiuperntin'e  in  orrlcr  lu  keep  »I1  iho  ncid  fuacd;  tbo 
line  I>F  is  thus  obtained,  eiidinj;  at  F  at  the  tucttlngpoint  of  pure 
bonJHjIi;  tieid,  I2t-i'.  TSF  therefore  repDMonls  the  moltiiig-poiut  curve 
of  the  Hcid,  oil  lulditioii  of  h)croasiug  amounts  of  wnter. 

Derivativei  of  Bentoic  Acid. 

SW.  Boixwjl  cUoridr ,  C,H,'COC1,  can  be  obtained  by  the  adion 
of  phoephot^s  ppntucliloride  or  oxycliloridc  iipoti  benzoic  ocitl,  or  by 
the  method  of  296.  5a ;  it  is  a  liquid  of  diaagrrcable  odour,  and  boib 

pr 

at  lft4^     It  is  inajiufaclurwi  by  ti-eating  benzaldchyde,  Cellj-CQ, 

with  clJorine.    Uulike  acetyl  chloride,  which  is  rapidly  docom- 


3W 


ORCAMC  CHEMISTRY. 


posed,  it  is  \'crj-  slowly  bcI<h1  upon  by  water  at  ordinary  tciupi^ra- 
turcs. 

Benzoyl  chloride  is  employed  in  the  introduction  of  tJio  benzoyl- 
pDup,  C,H,-00 — ,  into  compounds.   Tliia  Is  readily  effected  bj-  a 

mcthoti  discovered  bv  Bat-masn  and  i-ViiniTKN.  whioli  consiata-ia 
shaking  up  the  substance  in  alkaline  iwKition  with  bciizoyl  chloride. 

Bntzanitiik.  C,UjCO — NH-C,IIj,  is  prepAred  by  dropping  sisnlt 
qunnlities  of  caualic  poiiuli  Aiid  iM.-ni'^ylcliloritleintoanillDe,  a.w\  slink- 
ing lli«  miiliiiv,  vrbich  id  kept  cu<jI.  Finitlly,  oiutlc  potnith  is  ntUlml 
whh  constant  itliakiiig  until  ihustodlof  U^tizuylcbloridotiiis  vnoLshcd. 
Tbe  bcnzatillido  U  colloctutl  on  n  filter,  and  is  obtained  perfe«11y  pure  : 

c,iij-xn  iTTci.coc'.H.  +  Kou  =  c.Hj.xncJOCin.  +  Kci  +  h,o. 

Brmolc  anhydride,  C,H,C0"O'COC,TI„  is  formed  by  the  inter- 
action of  &  iienzciatt;  and  benzovl  chloride: 


C,K,COO|Xa  +  Cl|-Oa.'JI,  -  KaCl  +  CA00-O-COC.H,. 

At  ordinary-  teniperatures  it  is  verj'  stable  towards  water,  but  ia 
deeoin[H»Pil  when  iMjiled  wilh  it,  yit'lding  l)pn7.oic  acid. 

The  formation  of  ethyl  bctuoiUe  is  ttoinctimcA  employed  as  a  test 
for  ethyl  alcohol,  Hince  it  poesiasscs  a  charucleristic  peppemiint-like 
odour, 

Benzamide,  C,H|,'0ONH,,  can  be  prepared  by  the  action  of 
ammonia  or  animnniuni  rarbnnate  on  benzoyl  chloride.  It  ia 
crj'Btalline  and  diniorphoiis,  melting  at  130°.  It  ffa.s  stated  (104) 
tiiat,  on  account  of  the  influence  of  the  negative  acetyl-group,  the 
hydrogen  atttms  of  the  amido-group  in  aceta-midc  are  replaceable  by 
metals.  Bensamide  dispUiy»  tliis  property  to  an  even  greater 
extent,  this  being  dye  to  the  more  negative  character  of  the  bensoyl- 
group;  fur  the  veIupb  of  the  dissoi'ialian  constants  for  aoetie  acid 
and  for  benzoic  acidrespociively  are  ii  =  0'CX)18and  A'  ^  0*0060. 

Wlicn  tho  silver  eonipounj  of  Vniamide  is  IrcalM  with  an  »Ikyl 
kxlido  at  ordinary  lempcmtun-s,  an  O-etlier,    V/uolc  tmituxHur, 

CaH^'O^uu*  *)  i>  formed.    Ttie  conBlitation  of  l)ii«-8tib6tAO«o  b 

provfid  t)y  itR  yinlding  ammonia  and  alcohol,  iitst«'ad  of  ethylamiue 
atwl  twazoto  acid,  vben  treated  with   alkalis.     When,  liowever,   tba 


BENZOIC  ACID  AND  ITS  HOMOLOGUES.  387 

silver  compound  is  treated  with  an  alkyl  iodide  at  100',  a  N-alkjl, 

CgHj-O^Ji      '   ',  is  formed.    This  is  proved  by  tlie  decomposition  of 

the  latter  substance  into  ethylamine  and  benzi^Ic  nciii,  so  that  the 
silver  compound  must  havo  a  different  constitution  at  ordinary  tem.^ 
peratures  and  at  100'  (MT). 

Bemonitrile,  CjH(-CN,  the  methods  of  producing  which  were 
described  in  296, 3,  can  also  be  produced  similarly  to  the  aliphatic 
Tiitrilps;  fpr  example,  by  the  action  of  phosphorus  pentoxide  upon 
bcnzamide.  It  is  a  liquid  with  an  odour  resembling  that  of  bitter 
almonds,  and  boils  at  191°.  It  has  all  the  propvties  characteristio 
of  the  aliphatic  nitrilea. 

Eomoli^iieB  of  Benzoic  Acid. 

MB.  The  toluic  acula,  C,H,  <  pqoH'  ""^  formed  by  the  oxidation 
of  the  corresponding  xylenes  with  dilute  nitric  acid.  p-Toluic  acid  is 
one  of  the  oxidation-products  of  the  turpentine  oils,  which  are  first 

converted  by  oxidation  into  oymene,  CHi^      ^CH(OHi)i.   The  tolulo 

acids  only  dissolve  to  a  small  extent  in  cold  water, 

Fhenylao^ic  acid,  C.H.-CHi-COOH,  is  isomeric  with  them,  and 
can  be  obtained  by  the  method  indicated  in  the  folloning  scheme: 

C.H»-CH,-C1  +  KCN-*C.H.-CH,.CN->C.H..CH,COOH. 
Benirl  ehloiida  BeoKyl  cr>nld« 

It  is  readily  distinguished  from  the  toluio  acids  by  oxidation,  which 
converts  it  into  the  monobatic  benzoic  acid,  while  the  toluio  acids 
yield  the  dibasic  phthalio  acids  (380). 
/COOH 
ZylUs  acidt,  C,H,^CH,     ,  have  properties  corresponding  to  those 
\CH, 
of  beowlo  aoid ;  they,  too,  are  only  slightly  soloble  in  cold  water. 


ABOMATIC  ALSEHTSES   AlTD  KEIONES. 


/; 


Aldehydes* 

TJ 

S99.  BcmaldthyAt,  C^Hi-C/?,  is  the  best-known  of  tJie  aromatic 

aldehydes.  Lila»  tj(^  aliphatic  nhlohydra,  it  \r  formwl  by  the  osdda- 
tlon  of  the  corresfHMulin}!:  alcnhol,  Ix^nzyt  akohol,  CflH,'CH,On, 
and  by  disfillalion  of  a,  iiiixtiirn  of  a  b<?iizoate  and  a  formate.  It 
is  mani/fact unrd  by  lieatiiiR  haiziti  chlorUk,  C'bHjCH  •  CI,,  with  water 
and  caloiuin  carb<.>tiat4^,  a  inctliud  whose  aliphatic  analogue  is  of  DO 
practical  importance : 


C.H,-CH 


*-'=  +  H 


^'^-  no 

OH       "*" 


C,H,-cJ  +  2Ha 


Ttie  following  mcltitNla  arc  otnplojod  in  tho  prciiamUon  of  Its 
homologiies. 

1.  Oliloro^jalic  ester  in  rDowwI  to  react  with  an  aromatic  hydro- 
oarfaon  iu  presence  o(  aluminium  oliloride,  wlwn  l-ho  ester  of  aa 
a-kfltooic  acid  Ih  proiliicccl : 

c,H,  +  cico— crxxi.ir,  =  nci  +  o,h,.co-cooc,h^ 

CI>l'0rO'O3>ilJi>  ««ur 

The  froo  a«id  ia  obtained  by  flaponiftcalion,  anil  ou  dry  distillatioa 
]066S  OOf,  with  formation  nf  the  aldehyde : 

CHt-COOO,!!  =  CH,-oJ  +  CO,. 

S.  An  ftromn.l[(]  tiyilmcarhnn  is  tn>nt(v(I  with  n.  mixture  of  carbou 
nonoxide  iinil*b.vdri>cbtvrit;  acid  in  i>n.-»ciicc  of  nluoiininm  cfalondo 
andatracsurciiproiuotibrido.  It  niiiyl)i!aMuinL<d  that  formyl  chlor- 
ide, HOOOI,  is  obtaiDod  tu  nu  intcrmcdiato  product : 

CH,-CH,  +  ClOOH  =  HOI  +  Cn,.C,H,.c2. 

8.  Anhydrous  hydrooyaaic  acid  and  liydrocliloric  add  are  brongfat 

388 


AROMATIC  ALDEHYDES. 


Z^9 


into  contact  nilli  aromniic   hydrocarbons,  when  fUdehydes  are  pro- 
<ln4ed,  tUQ  aidime  boing  fornifrd  as  &q  iaiormodi&lo  prodaot : 

cn,  +  cira  +  nci  =  c.h,-ch  \rr.iici; 

Benialillini!  Iijijruchlurhla 

tyij.oniNU.Hci  +n,o  =  c.H^.c5  +  nh,ci. 

Benxalrlehyclc  is  found  in  nature  as  a  constituent  of  amygdalin, 
CapU,,N*0„  (242);  on  Ihie  account,  it  ia  called  oil  oj  bUlcr  almonds. 
It  i:}  a  li()uid  of  agrccalile  odour,  is  ^liglitly  soluble;  in  water,  boils 
at  179°,  and  has  a  specific  prnvity  1-[)d(>1  at  IS"*  It  has  most  of 
the  propcrtips  of  the  atiplmtic  aldehydes :  it  is  rpn<lily  rtxidized,  even 
by  the  oxygen  of  the  atmnspliem  («ijK>ciiLlIy  when  cijiosed  tr)  sun- 
light), reduces  an  anummiacal  silver  soliitinn  with  fDrmation  of  a 
nunor,  >'iel*U  a  cr>'8tallirir  additiou-pniduct  with  sodium  hydrogen 
sulphite,  a<l<l»  on  hydrocyanic  at^id  and  hydrogen,  forms  on  oxlitic 
and  a  phcnylhydmzonc,  etc. 

There  are,  however,  points  in  which  it  <lilTere  from  the  fatty 
aldehydes.  Tims,  with  ainninnia  it  dots  not  yield  a  compotiml  like 
aldehyde-ammonia,  but  pniduci-s  bijriTfAaiiamulr,  (CftEI»CH)jN,, 
formed  by  tlie  union  of  three  incjlccules  of  bciizalili:Iiy(lc  and  two 
molecules  of  anuiionia: 

3CAC^  +  2n,N  -  CC,H.CH),N,  +  3H,0. 


ITie  behaviour  of  the  aromatic  aldehydes  towanls  alcoholic 
potash  is  characterifitic,  one  molecuieof  the  aldehyde  being  oxidized, 
and  the  otiier  redueed  {ef..  however,  117);  thus,  beuzaldehyde 
yields  potassium  benzoate  and  benzyl  alcohol: 

2C,H.-c5  +  KOH  -  C,H,-COOK  +  C,H,-CH,(>H. 

^H         The  aromatic  aldehydes  condense  readily  with  dimethyUmlino 
^^  or  phenols,  forming  dejivatives  of  tripheuylmetlmne : 


39°  ORGANIC  CHEMISTRY. 

It  lias  b«en  obaerved  that  darinic  llie  (ucidation  of  TariotM  sob- 
bIadcos  ip  the  air,  tt*  niucti  tayfcva  is  roadcrci)  "nctirc  "m  it  taken  ap 
'by  tha  »iit»UiiCie  uii(k-r  oxiiliilioii  ("  luurgniiicl-litmiiiitr}-,^  SSI);  thia 
ia  true  of  benxalilohyilo.  If  il  ia  left  for  sevorn)  weclta  iu  eooiact  vitfa 
walpr.  indlgoHiilplionlc  acid,  ami  iiir,  the  juiind  aiiKHiiit  of  oaygvn  la 
nsvil  np  in  oiidizini*  ilio  in<lif»<>  demaliv^  as  in  eouverlin^  Iho  bciizal* 
di-hyde  inin  beiiEolc  add.  Baktkr  baa  shown  tbat  bentoj*!  hydrugen 
|H'Toxide,  (',[|,CO-0-OII,  U  formed  as  an  Intcnncdialo  prodact,  and 
oildises  the  iiidifcoxi'lrlionicaeid,  bmnj;  f tiwlf  ivdaoedto  bemnfo  «cid: 

c,H,-cno  +  o,  =  o.Hi.co-o-on ; 

CJkOOO.Cm  +  Indigo  =  C.IT,.C00H  -f  Oxldlaed  iniligD. 

Th<  oxUIftlton  of  bciiialdebjrde  In  tlie  air  must  iticnifora  be  ooraidand' 
to  tttkeplaM  ttiua: 

c.n.cno  +  o,  =  c,H,co.oon; 

QHrTO-OOH  +  CHjCHO  =  8C.H»-000H. 

BlKTiB  has,  In  fact,  proved  thai  lionxayl  liydro(ceii  jMroxide  dissolvoi 
when  added  to  bcnz4ild«hj'dv,  but  Ihnt  tbv  liquid  gmduaUx  otwDgoa  to  • 
aoUd  mass  of  pure  benzoic  acid. 

Zatones. 

300.  Tho  aromatic  kfiones  can  be  subdiviiitd  into  the  mixed 
aronmtic-fatty  kfUiii<«,  ami  ihe  true  aiY)riiatic  kcrtom's,  Thr  best- 
known  member  of  the  first  class  is  acetophcnonc,  C^IfC'O-CH,; 
it  OHii  he  nhtHJnptl  by  distilling  a  mixture  af  c-jUciiim  aoplatc  and 
bpniooto,  or  morp  n-adily  by  the  adtiitiiin  of  altiminiuin  elilnndo  to 
a  niixtuTe  i>f  l>pnzene  and  ncptyl  ehlnriile.  It  is  a  oryKtalline  stib- 
stanixT  of  agreeable  odour,  melting  at  20"  and  boilinj;  at  200°;  it  is 
rflElitly  Hobibli!  ill  water,  ami  po»<essca  all  the  pn)|icrti€s  of  the 
alipliatic  ketones.  It  itt  (-mploycd  as  a  aoporitic  under  the  name 
"  bypnone." 

Benznphcnonf ,  C,Hj-CO'C,H,,  is  a  true  aroniatic  ketono,  and 
can  bp  obtaineil  by  the  dry  distillation  of  calcium  benxoate,  or 
by  the  action  of  Ijmzene  and  alurainium  chloride  upon  bciuoy 
clilnridr,  or  carbnnyl  cliloride.  This  compound,  although  a  Into 
aromatic  derivative,  behaves  exactly  like  an  alipliatic  ketoue; 
on  reduction,  it  yields 6CTwAyrfro/,CBll4-CHOH*CnH,;  bcnspinocon*, 

<C,H,),0— -f  CC^J,^  is  amultancoualy  formed  (156). 
On    OU 


/IROM/iTIC  KETONES  AND  O'XIMES.  391 

Although  the  mechanism  of  Friedel  and  CBArTS'  synthesis  (868,  3) 
of  the  hoDDolognes  of  benzene  has  not  been  aatiafactorily  explained, 
B0E8BEEN  has  put  forward  a  complete  explanation  of  the  synthesis 
of  aromatic  ketones.  Ho  has  proved  that  the  acid  chloride  first  unites 
with  the  aluminium  chloride : 

CH.COCl  +  Aid.  =  C.H.COCI-AICI,. 

On  addition  of  one  molecule  of  benzene,  one  molecule  of  hydrochlorio 
acid  is  evolved,  nith  formation  of  a  crystalline  compound  : 

CH.-OOCl-AlCl.  +  C.H,  =  C.H».C0-C.H.-A1CI,  +  HCI. 

On  addition  of  water,  a  quantitative  yield  of  the  ketone  is  obtained : 

C«H.-C0-C.H,.A1C1,  +  «H.O  =C.H,CO.C.H.  +  AlCl..nH,0. 

The  reaction  therefore  takes  place  in  three  stages. 

Benzophenone  exists  in  two  modifications;  one  of  these  is  un- 
stable and  melts  at  27°,  and  the  other  is  stable  and  melts  at  49°. 
The  difference  between  these  two  is  a  purely  physical  one,  since 
different  derivatives  of  them  are  unknown. 

Ozimea. 

301.  Investigation  has  shown  that  some  of  the  oximes  of  the 
aromatic  aldehydes  and  ketones  exhibit  a  peculiar  kind  of  isomerism. 
Thus,  there  are  two  isomers  of  benzaldoxime,  hemBji^aldoxime,  a 
liquid  boiling  without  decomposition,  and  bemsynaldoxiTiie,  which 
is  solid,  and  on  treatment  with  acetic  anhydride  readily  loses  water, 
f onning  benzonitrile : 

C^jCIH 

III       =  C,H.-C=N  +  H,0. 
N|OH 

The  onfialdoxime  yields  an  acetyl-derivative  with  acetic  anhy- 
dride. 

It  has  been  proved  that  no  isomers  of  the  ketoximes  p,>C;NOH 

exist,  when  R  and  R'  are  similar ;  two  isomers  are  known  when 
these  groups  are  dissimilar.  Benzophenone  oxime  and  its  derivatives 
furnish  examples  of  this.     In  spite  of  many  attempts  to  prepare 


39" 


ORGANIC  CHEMISTRY. 


an  isomer,  benjophenone  oxime-ia  only  known  in  ooe  modiBcatioix. 
When,  howeve-T,  hydrogen  in  one  plienyl-gmup  13  substituted,  two 
isomeric  oximes  can  be  obtained.  Monnchtnrobenzophenone, 
C,H»  ■  CO  •  C,H,Cl,  monobrtJmdbt-nzophcnone,  C^H.  ■  CO  •  C^n.Hr, 
ttjlylphcny  Iket^Mic,  CH»  "C.H,  ■  CO '  C^Hj,  anw>-lphcnyIketone, 
CH,U-CaH,'CC)'Ci|1Is,  anil  many  utbcrs,  arc  examples  of  ketones'] 
which  yield  two  isomeric  oxinics. 

After  several  ineffcetual  attempts  in  explain  such  isomerism 
by  the  ordinarj*  stnietural  fornuila-,  the  following  stcrcochemieat 
explanation  of  the  obsened  ^acls  lias  been  Mlopted.  It  is  assumed 
that  the  three  nffinitips  of  the  N-atom  are  directed  towards  the 
angtes  of  a  tetruJicdron,  the  nitrogen  atom  itaolf  b4^iig  situated  at 
the  fourth  angle: 


Wlien  the  three  nitTogen  bonds  are  linked  to  carboQ,  as  in  the 
nitriles,  the  following  spscial  representation  is  obtained: 


Stereoisomcriisin  is  here  impoasible:  expcrienoe  has  shown  that  none 
of  the  nunierous  nitriles  katnm  ocoun  in  two  fonns  due  to  isomerism 
in  thcCN-groupp. 

A^Tien,  however,  the  nilmgrn  atom  is  linked  to  carimn  by  two 
bonds,  two  isomeric  forms  become  possible: 


STBREOISOMEMSM  OF  THE  AROMMTfC  OXIMES. 
l&eMean  be  mun>  readily  repn-senlcd  by 


393 


X-O-Y 


X— C— Y 


li-z  •"-   z-11 


I',  will  be  ob8or\TH  Ihat  different  oonliguntioiifl  for  siich  eompoiinda 
are  ntily  obtainwl  wliwi  X  and  Y  are  dItTerent,  since,  when  they  are 
nmilar,  the  figures  beoome  identical.  Tliis  agrct'^i  witlri  the  fauti 
etateJ  above. 

It  CAU  Also  be  del«rmhii»l  which   confiftiiration   belongs  to  each 
isomer,    lliu  iwu  tsoaierlc  twuMltloxiiues  li&va  ttia  roriuuiiu 


CH.— 0-H 

II 
N-OII 

Bcnw^naldutUao 

L 


and 


cii,— c— n 

I! 
IIO-N 
Benua  n  n  ftldoslma 
U. 


In  tonnula  I,  H  find  OH  aro  nwimr  togntlier  tlmn  in  ronntiU  IT, 
irhioh  explains  the  roni]iocu  nnlh  which  oii«  tuolcculo  of  irnter  ia 
«plit  oft  rrom  one  nidaxime  (<yw).  ^n*!  ■"»'  trom  the  otiior  (anti).  On 
thl^  nccouiit  uouliitu ruCion  I  is  lussigued  to  tho  «^(taldoxime,  and  coo- 
con  fisuraliou  n  to  tliotiJif/rilJoiiinc, 

Tho  conflgiiralion  of  the  Itotoiiinoa  can  be  dotermincd  by  (h« 
BeckuaMK  trituHforrantioii  ill2»,  hA  U  mndc  clear  \n  tltu  fullovriag 
eiauiplo.     Tvo  Isomera  of  nQisylphenylketoxinifi  arQ  known, 


CU.O-C.H»-C— C.H, 

II 
2(-0H 


and 


CH,OCH,— 0— CiD, 

HO-A  • 


IL 


the  Bnt  melting  at.  137'  and  tho  socood  at  US'.  Bf  the  Bickmakk 
tranaforiDHtion,  tho  oximo  of  Uiglicr  tnnltiug-|infnl  j'kililit  tho  ]tniUd« 
of  aiiiitic  aoid ;  that  of  lower  mcUiiig- point,  the  nttisiJo  of  bonsotc 
H«>d.  Tbe  former  muHt  th^reforo  tiavB  cootlguniiioii  X.  and  (be 
Becoud  coiiflKumtioti  II,  bocauiio  io  I  th«  groups  OU  and  0,11^  ar« 
o«it  to  «acb  other,  and  exchange  plBces, 


CH.OC,H.-C-On 

II 


CH,0  0,H,— C=0 

SU-O.H,' 


394  ORGANIC  CHEMISTRY. 

prodocing  the  anilide  of  aniBio  acid,  CH,O-0aH«-CO0H ;  vrhile  in 
II,  anisyl  (OH,0-C,Ut— )  and  OH  are  next  one  another,  and  exchange 
plaoee,  yielding  the  aniside  of  benzole  aoid : 

HO— C— 0,H,  0-0-OA 

il  .     -*  I  - 

O^O.OA~N  CH.O-C.H.-NH 


SIAZOCOHPOUNDS  ANB    HYDRAZINES. 


I.    siAzo  coMrounDs. 

Thp  (liazo-oonipounils  rjf  the  aroiiiatic  scri€«,  dwcnvopod  by 
Cbjess  ill  1S80,  are  not  merely  o!  tlieiirelical  irupuruiiicc.  but  play 
an  important  part  in  the  maoufacture  of  dyes.  In  the  fatty  series 
only  Qmino-coinpouiids  of  a  special  kind  arc  capable  of  yielding 
fliaKu-com[K3UiicliJ  (201),  while  their  funiiutiuQ  is  a  general  reaction 
of  the  primary  aromatic  atniiios;  the  propertif  o}  undrrgoitig  dituo- 
li'tuti'on  IS  diaracttrixlk  of  aroiruilk  amines. 

Diazo-comixiunds  are  substances  containing  tbe  Jicroup  — N, — . 

jTIicj'  are  divided  into  two  claHscs:  the  dinzonium  compounds,  with 
properties  analogous  t^  ammonium  compounds,  from  which  their 
name  is  derived;  and  the  true  diazo-eoiii]jouinIs,  in  which  the  group 

[  — N, —  ha*  tht-  w)iiKlitutiou  — N = N — . 

The  diazonium  compounds  ihemselves  arc  of  slight  importance, 

'  «jid  are  usually  not  isolated.  The  numerous  traiutformtitioiis  which 
they  can  undergo,  however,  with  fomialion  of  a  great  number  of 
derivatives,  account  for  the  great  importance  of  these  substancee 

(in  the  chemistry  of  the  aromatic  comijounds. 
Diazonium  eonipoundK  art-  fomiwJ  by  the  action  of  nitrous  add 
«D  tJie  salts  of  aromatic  amines: 


C,H».NH,-HNO,  +  HNO,  =  2H,0  +  C,H».N,.NO,. 

Atilllno  niiritt*  n<>nuiDaillkionliiin  nlirat* 


V 


TUs  is  usually  carried  out  by  adding  a  solution  of  sodium  nitrit* 
to  one  onntaining  nn  ecjuimolecular  pmpnrtion  of  iJie  amino-.'^Ut 
and  an  equivalent  quantity  of  a  free  mineral  acid,  the  reaction- 
mixturc  Ix-ing  c(H>led  by  the  addition  of  ice,  ua  the  dinzomum 
cnmpraunds  decompose  very  readily;  a  solution  uf  the  bennenc- 
diazonium  salt  is  thua  obtained.  In  order  ^to  isolati!  eurh  a  KtUt 
u)>efuctuduizfm\umehlf^de,  CaH,-N,-C'l,  in  the  nolid  state,  a  small 
uantity  of  concentrated  hydrochloric  acid  is  added  to  an  alcoholic 
eolullon  of  aniline  hydrochloride,  and  then  amyl  nitrite,  whereupon 

39i 


396 


ORGANIC  CHEMISTRY. 


the  dlazonluni  cKloiide  ci>-staUizcs  out.  The  r]r>-  duuonium  salts 
are  exceaaively  explosive,  and  must  tht-rrfon-  he  handlttl  with  grrat 
core;  tJiey  arc  quite  hai'inlc^  in  aqueoim  ttalutioD,  and  an  it  iit  tin- 
neowwarj*  t^  isolate  them  in  order  to  employ  them  in  reactions, 
they  are  seldom  pneparwl  in  the  soliii  state. 

The  group  X.X  of  the  diaroniiim  compounds,  of  whieh  X  is  an 
acid-refiidue,  is  only  linked  to  one  carbon  atom  of  the  benzene* 
nurlcuH,  for  all  their  transform  ati<iii.s  produce  svdwtances  contmning 
a  group  likewise  linked  to  only  one  carbon  atom  of  ihe  nucleus. 

The  constitution  of  the  diaBOiiiuni-group,  ^-NjX,  can  be  de- 
ilueed  from  the  following  considerations.  In  many  respects  the 
group  CbIIj'N) —  bohaves  similarly  to  an  alkali-metal,  and  srill 
more  to  the  ammonium  radicle.  With  strong  mineral  acids  it 
forms  colourless  fiahs  of  ofviitral  reaction,  like  KCl  and  Nir,Cl, 
while  itji  Halts  with  carlmnic  arid  rraemhic?  the  alkuti-earbonstcs  in 
haviii£  an  alkaline  reaction,  due  to  hydrolytic  dis3H>ciation.  The 
conductivity  of  the  diazonium  mXln  of  hydrochloric  and  other  acids 
sliou'8  that  they  arc  a^  strongly  ionixed  as  KCl  and  XH^CI.  Simi- 
larly, diazonium  chlorides  yield  platinum  double  salts,  such  as 
(C,HiN,Cl)jPtCI,.  which  diswlvc  with  rliflicnlty  in  water.  Otber 
double  salts,  such  as  (C^HjNjC'UAuCl,.  have  also  been  obtained. 
Free  bfrnentdiatonium  hjAroxuic,  C,H»-X,-OH,  ia  only  known  in 
ai|uem])i  ."lohilion,  which  has  a  strongly  alkaline  reaction.  It  is 
obtained  by  In'stirigthe  a^iueoua  solution  of  the  chloride  with  silver 
oxide,  or  by  the  a<!dition  of  the  wiuivalent  quantity  of  barj'ta-watrr 
^o  the  sulphate.  It  is  cdloiirlcss,  like  causlic-imtash  solution,  but 
thi-ouch  dcconipusitiou  gradually  deposits  a  flocculent,  resin-like 
substance. 

The  existence  of  a  pentavalont  N-ntnm  in  the  diazoniiim  salts, 
just  as  in  those  of  amnumiiim,  mii-st  thcn-fon!  be  a»«uniL-d,  the  basic 
properties  of  each  being  due  to  its  presence.  Two  formube  are 
therefore  posMble : 

C,H,N=NX    or    CA>r^N- 
As  will  be  proved  in  303,  the  preference  must  be  given  to  the  second. 


Beaetions  of  the  Diftzonium  CompouDdi. 

303.  Many  of  the  reactions  of  the  diazonium  compounds  aie 
characterized  by  the  elimination  of  the  group  — N, —  as  free  nitrogen 


REACTIONS  OF  THE  DIAZONIUM  COMPOUNDS.  397 

from  the  molecule,  and  its  replacement  by  a  substituting-group 
linked  by  a  single  bond  to  the  benzene-nucleus.  Extended  re- 
search has  revealed  the  best  conditions  for  obtaining  nearly  quanti- 
tative results  in  most  of  these  reactions. 

1.  Refilacemerd  of  the  Nj-group  by  kydroxyl. — ^This  is  effected  by 
allowing  the  aqueous  solution  of  the  diazonium  salt  to  stand,  or  by 
warming  it: 

C,Hs-N,-Cl  +  HOH  =  C,H(-OH  +  N,  +  HQ. 

2.  ReptacemerU  by  an  alkoxyl-group,  — 0  ■  CnHjn^,. — This  is  car- 
ried out  by  boiling  a  diazonium  salt  with  alcohol ; 


C^-N,-|HS0,  +  H10-C,H,  =  C^O.C,H,  +  N,  +  H^,. 

3.  Replaeement  of  the  diazonium-group  by  hydrogen. — Under  cer- 
tain conditions  the  diazonium  salts  do  not  yield  alkoxyl-com- 
pounds  with  alcohols,  but  produce  the  corresponding  hydrogen 
compound,  the  alcohol  being  converted  into  aldehyde : 

NO,  C,H^-N,-a  +  CjHsOH  =  NO^.C.Hs  +  N,  +  HQ  +  CH,0. 

p>Nitn>beDzaaedlubiiluin  NiimtwnMuo  AceUldehrds 

chloiids 


By  this  treatment,  p-diazobenzenesulphonic  acid, 


when  treated  with  methyl  alcohol  under  dimiaished  pressare,  jlelda 

only  beozenesnlphonic  acid,  the  diazonium-group  being  therefore  only 

replaced  by  hydrogen.    Under  a  pressure  of  30  atmospheres,  however, 

flO  H" 
only  anisolssalpbonic  acid,  CaHj<Qj,Jj  ,  is  formed,  N,  being  replaced 

by  the  methoiyl-gronp,  — OCH,. 

4.  RepUtcemerU  of  the  diazonium  group  by  halogens. — ^This  is 
effected  by  treatment  of  a  solution  of  diazonium  chloride  either 
with  cuprous  chloride  dissolved  in  concentrated  hydrochloric  acid 
(SANDMBTia),  or  with  finely-divided  copper  (Gatterwann)  ; 

C,^-N,-CI  -  C,H,-C1  -I-  N9. 


398  ORGANIC  CHEMISTRY. 

Cuprous  chloride,  nod  dnetf-dividM]  copper,  bave  hcra  a  catalptHs 
KCtion  ;  it  ifl  jirobaUo  thnt  n  coptier  vompouiiil  is  rormed  m  an  iotor- 
m«dtH(«  jtroduct,  aiid  m  ».ttt:rva.riU  AtictimimiuHi. 

Itcplacumviil  \)j  bnniiiin:  m  cnrrk-d  out-  in  the  same  way:  thus,  in 
the  preparation  of  brotuobuuzGiie,  a  soltitioii  of  polassJum  bmrntilu  is 
lukkd  Id  ail  viiiiifOLis  itiiliitii>u  tit  twiiwiiudiaxDiiiiim  aiilpliaxi  con(»iiiing 
froe  siilplitit'ic  nrriit ;  i>n  nddiiioii  of  i!n)i[N;r-diui  to  tiiU  mizturo, 
iiilroguii  ificvolvcil,  atHi  brnTnnhoiiBBtic  is  lormwl, 

KeplacenierU  by  iodine  takes  pinw  ivnrlily  when  a  warm  Boluiion 
of  polawiuin  iodido  Li  add^d  tu  a  diaKDUluui  tiuIpliateaolutivD ;  it  n 
unoftCMSsiirjr  to  employ  copper  or  cuprous  ctiloride. 

5.  Replacctnenf  0/  Oie  dioioniwn  group  by  the  Cti-ifroup. — This, 
too.  readily  takes  i*iaoc  in  presence  of  copper  compounds.  T'te 
solution  of  the  (liazanium  salt  is  uliled  Ixi  oni.'  of  potassium  cupraus 
cyaiiiJe: 

C,H,.N,.Cl  +  KCN  =  C.BI,.Crf  +  N,  +  KSI. 


Thi«  rc&rtion  is  »f  gmat.  tmportuiicr  for  the  8>'nth«>iB  of  aromatic 
[■acids,  which  can  be  got  by  hyrlroIyzinR  the  nitrilw  thus  obtained. 

6.  Olfier  rwctifjiu  van  bo  carriiMl  ont  l^y  Ircnliiig  dtaiMiiinoi  aalls 
with  siilpljiircttitd  livdr(i|'L<i).  tvliloh  ywWs  C'litiiiuiinds  i>iiit;iiiiiDF; 
sulpiiuc  linked  lu  tht;  bcitzciic-iiuclDiia.  Uy  llii&  trmlmctit,  b(!i>r,<>iie* 
dinzoniiim  ctdoride  jiolds  phenyl  sulphide,  K-gll^iS,  two  molcoii1«s  of 
tiiu  cliluride  reiiclliig  n'illi  <mio  of  HiiliMiiirullcd  )iy<lrof:cn. 

Tli4>  Ni-tii'r>np  onii  tiUo  bn  r«pliiri!d  by  uroiDiiiio  liydrocitrbon- 
rcsidues  ;  thus,  ttipficnf/l,  C«II,-Oo1l,,  is  oblaintMl  by  Irv.-iling  dry  bfna- 
etiediaxotii  urn  ctdoridf  with  btiiiz^'iie  iu  preaanoa  of  a  small  iitiantitfof 
aluuiiiiium  ciilurida  : 

CHj-N.-oi  +  H-cn,  =  c,ir,.c,iTt  +  N,  +  hi:l 

Tlioso  reactinno  illustrate  the  ini|>firt&nce  of  the  dtazonium  salts 
as  int4?niifdiale  products  in  the  pn-pni-aliim  of  iuiin<Ti«i»siih.stanres. 
Since  rhey  arr  ilcrivrd  fniin  the  utnincs,  which  an-  prri«in-(i  by  the 
reduction  of  nitro-^om pounds,  it  i^  evident  that  tJic  nilTalinn  of 
aromatic  derivatives  is  a  r<-8ction  of  great  iniportjiice,  for  the  nitro- 
group  can  he  rc|)laped  at  will  by  almost  all  ot  iter  t'lements  or  groups 
l^  meanaof  the  amiuo-twm  pounds  and  diazonium  corapoutida. 

Haktzsch  baa  eiplsitied  the  reactions  of  the  diazoiiium  ouiti|H>unds 
by  tuBumiug  that  tliey  lbe[aa«lv«B  do  not  eutt-r  into  rcuctiou,  biit  are 


REACTIONS  OF  THE  DIAZONIUM  COMPOUNDS.  399 

first  converted  iato  a  Ayndiazo-oompouiid,  which  then  decomposes 
with  evolution  of  nitrogen.  The  formation  of  phenol  must  then  bs 
T^resented  thus : 

CA  OH  C,n»   OH         C,H,OH 

(  [         I         _,     Phenol 

NBlf    +  =  HOI  +     N=N  NbN; 

I  «tntDUio- 

Cl  H  IvdroUdA 

DUtODtum 
olilorlda 


and  that  of  chlorobenzene  thus  : 

0,Hi  CI       C,Hj  CI  C,H,CI 

ibi 


J  I  I         I    —4     ChlorobeaMna 

N=N  +       =      N=:N 


I  I  nnDlOio- 


H  chlorlds 

The  reactions  between  diazonium  salts  and  alcohol  are  explained 
■aa  follows : 

C,H,  00,H,  /C.H,  OC,HA        C.H,-OC.H,  [ra^Jtonof. 


NbN+  I 
CI  H 


/C,Hs  OC,HA         C,H,-OC.Hb 

V    N=N        /  ~*       N=N 
CI-H  Cl-H 


C,H(  H  CjHj — H  [FomiMIon  of » hydrocarbon]. 

NhN   +  I    -*       NsN 

CI  CiHjO  CIOC,H(  [Splitting  up  Into  HCl  and  aldahyde,  C,H,OJ, 

As  these  transformations  of  diazonium  salts  cannot  be  explained 
bfi  the  other  possible  structural  formula,  Cgllg-N  .^  N>X,  it  is  evident 
that  it  must  be  rejected  (802). 

Moat  of  the  syndiazo-corapounds  are  very  unstable,  however;  they 
change  readily  into  anfidiazo-compouiids,  in  which  it  is  assumed  that 
the  phenyl-group  and  acid-residue  are  far  removed  from  one  another, 
and  can  therefore  no  longer  unite: 

C,H.  X  *?«^' 

N=N 


u 


(jmlXazo-com  pound;  antfDlaio-com  pound: 

C«tli  Kiid  X  can  unite  C|Hi  and  X  cannot  UDita 

with  one  anolher  with  one  another 

In  oertain  cases,  such  as  that  of  the  diazocyanides,  Hantzsch  baa 
been  able  to  isolate  these  intermediate  products,  and  thus  afford  a 


400 


ORGANIC  CHEMISTRY. 


proof  of  tbesa  riows.  For  «x«ropl«.  wlisn  cyanidfs  arencldecl  lo  diazo- 
tizedp-cliloroitnilinc,  Cl-CaU,-Ml,. p-chlorobcnzoDitrile,  01-C(tI,-CK, 
is  not,  inimcdJHiely  fortnvd;  it  is  possible  to  isolate  a  yellow  inierm^- 
di»l«  |jroducl,  ClO^IIi-Ni-CN,  wbicb  yk-lds  j»-<)lilorobeDJoiiilrileafler 
«iJditi«ii  ot  co[j|H-r-Uuii[,  i)ie  ncUon  being  accoinpunied  by  mi  energelio 
OToluIiou  lii  iiicrofjcn.  This  y«11oiv  iiituriocdiato  j?>GliloroboDz«De- 
jyfiiliazocyriulde  i».  )iuw«vei,  vury  uiiBtabI«.  anO  sp«(<di)jr  changrs  lo 
Ml  isODtcr  ([b«  <iii^'-com]K)ui)dj  which  does  not  react  with  copper- 
dost.  The  fitcronclieniicRl  llieory  thus  Affords  a  satisfactory  explsoa- 
Uon  of  tbu  obii^Tvvtl  [>bpiiuotena. 

It  mi|:)itU-Kii)U!tntlfd  tbaLtb«  iin»iablt! primary  prodrjtlsitiaKoninaL 

ejAnidc,  i        .     This  cannot  be  tbe  caw,  for  &acti  n  CTanldc' 

N 
toast  ha?*  proiwni^-s  niiHlogons  to  those  ot  potassLum  cyanldtt,  it  must 
be  colourless,  liko  tlio  oHit-r  dlAzonium  uUt«,  have  an  alkolloo  reaction 
in  aqueous  solution,  anil  conduct  tbe  electric  current,  wbereiu  tlio 
aaslabit!  pnmnry  product  possotwcx  none  of  iheM  properties. 

Mnrt'ovcr,  rni  uuiaolc  cIcriTativc,  CniO.O.U,NcON,  was  diacoTcrod 
'by  lU-VTZscB,  nliich  toust  be  looked  upon  as  a  diflE'iniiim  cyanide, 
oincu  itA  »i|ui-aii.<)  Aoliition  does  poaaesa  all  these  propenioR. 

Bcnn>nitdi.-ucuniuin  hydroxide  ia a BlroD;;bn.<te,  bm  n<Acls  villi  allcalia 
h)  i\  manner  tiuilti  iitikiinwii  nnioii)j:  the  slroDic  mineml  bn»(«.  Wliea 
a  (11a.taniiim  «iilt  in  i\iUlv*\  lo  a  atron);  .viUiiion  of  cauitUc  potaitli, 
a  pota&sium  derivative.  (',II.-S.-OK.  sc[wraic»  out.  Tlic  rvaclioo 
talcc-8  placf)  not  only  in  conceiilrattd  but  also  in  dilute  solutiotts. 
Wlxni  ti  ilihilo  fioluliciii  nf  bi?iii'.fitedi»Koniuin  liydroxido  in  tn-aird  wiib 
an  4>quiTn]0ul  quantity  of  caustic  scidn  in  diliitt'  soluiioo,  tlie  molcctilnr 
condiictdrlty  of  llie  mixtum  iscunsidvrably  1rs«  llinn  llii;  sum  of  ihe 
twoeloclrie  oontluetlvlijcs  of  the  solulioiiM  sci>«rati'ly  :  ii  rollovathata 
porlioti  of  ttie  ions  (ClIiNuO/  +  II'  and  Na'  +  OH',  wliicli  have  bnm 
brouglit  into  oontaut,  bavu  fbangnd  to  tbe  nou-imiizeil  &tato— anion  of 
H'  and  Oil' — that  ta,  tlio  formation  of  a  sail  niufil  bavc  occnrrod. 

ThtiH,  the  d)ii7.oninni  bydroxido,  which  is  n  alrnit;;  Iwso,  op]>ean  to 
behnvu  liko  ku  acid  also.  Siooo  this  ia  very  improbublfl,  IlAiO'MiTB  aa- 
SQincs  that  an  «<c|utlil>rium  oxista  in  tliu  a^utxius  solution  iMrtwwQ  tb« 
diazoniuio  hydroxide  and  tbo  syndiazoliydroxide  (p.  8S9}: 


C.H»N-On  _  C,H»N 


N 
Dlaxunlitm 


HON 

lijdraiUl* 


Beiapposes  tbat  tbo  alkali  dcrivatiTea  araderiTed  from  tbe  latter 
QOtBpound. 


DIj^ZO-COMPOUNDS. 


401 


804.  The  importftnce  of  the  diazoniiim  compounrts  is  not  con- 
fired  to  reactions  in  which  the  nitrogen  atoms  are  eliminated,  idtioe 
important  tlprivativ«t.  in  which  tliey  are  retained,  are  known, 

1.  Dinzoam\itn~rom'pnun/is  are  olitaiiieil  by  the  actiiia  of  primary 
and  secondary  amines  upon  clifuioniuin  ealta: 


CA-?frlCl_+H,NHC^,  =  C.fr,N,-NHC„II,  +  Ha 

DbumimlnoboDswie 

They  aro  also  obtained  when  nitrous  acid  reacts  trith  Tree  aniline 
instead  of  an  aniline  salt.  It  may  he  siijiposrH  that  in  this  reaction 
benzcnediazoniiini  hydroxi<ie,  or  rather  benzrnediazohydmxide,  is 
first  formed,  and  ta  at  once  attackcifl  by  a  molecule  uf  thu  aniline  still 
present; 


1.  C,Ha-NH,  +  UNO,  =  C^Hi-Xj-OH  +  H,0. 


II.  C,Hs'N,-;oH  +  H  NHC,tf,  «  C^,-.V:N-NHC,H,  +  H,0. 


BftD.n[)c<liaiol>7iIri  ziila 


Tile  diazoamino-rompoimda  are  crystalline  and  have  a  yellow 
colour:  they  do  not  unite  witli  acitU.  In  aeid  hoIuiIou,  they  are 
converted  by  treatment  with  nitrous  acid  into  diazuniuni  salts : 

C^*N:N*XHC,H,+  HN0j  +  2Ha  =  2C«UjN,  0  +  211,0. 

The  most  characteristic  property  of  the  diazoainino-nimpounds 
b  their  rratly  tran»fnnimtion  iiilo  isomers,  the  rtmirtaata-rem'poundt: 


DlAtOOJllIoobFIIMDr 


A  ni  ICUM«Oh*D*HI« 


Tliia  ia  best  carried  out  by  adding  aniline  hj'dmchloride  to  a  solu- 
tion of  diazoaminobeiiiene  iu  aniline,  and  warming  the  luixlure  OD 
the  water-bath. 

The  aniido-group  in  aminoaaf^xmene  is  in  the  para-pusition  to 
the  azo-group.  When  the  para-poGiCton  is  alreafly  occupii-d,  tbe 
amido-group  tokcs  up  the  or(/(f>- position.  Aminoanobenzene  and 
many  of  its  derivatives  are  dyes  (320). 


401 


ORGANIC  CHEMISTRY. 


The  ftbove  equxtion  iadicAlas  tliat  tliA  iraii'ifoniialton  of  diazo- 
aiDinoheTiz(<n«  into  fttninoaKibeiizene  is  ft  unimoSeculftr  reaction  (*'  In- 
organic Cbemintry."  50).  Ooldsc-iimjdt  provc<l  by  MptTitntrit  thtit 
this  riow  H  curruol.  Il«  <liti9nlv«d  diiizixtiatiioWrixi'iie  in  aniline,  And 
fleii>rmiii<!d  iho  quARiity  of  diasnaminobenscnQ  Htill  prcaeDL  after  t-ho 
lapsQ  of  Icn4)wn  periods  of  time. 

Tlie  aiiilint!  liydmcliloride  iianally  &ili)i>(l  in  i?jirryiiig  out  tills  expeH* 
ment  \\n»  iiMirrly  nt-ntAlylic  itccptfrntlii^rlTrct  upon  liio  rvactiort;  Ibis 
is  pi'ovcil  by  lliu  UQiform  kEicrooiso  in  itio  volucily  ranslatit  vriib  Id* 
CKtific  in  llio  amuuiil  of  nnilino  hydrochlondo,  mid  in  oth&r  ways. 

It  lias  also  been  sbown  tliat  when  different  nails  of  aniline  are 
employed,  their  catalytic  inflaonco  vnries  in  nmaiint,  and  is  almost 
proiwrlional  lo  their  detcree  of  innimtion-ln  aqneous  eoliitlon.  This 
vriut  provoil  )>y  Goi.DRCHHinT  for  the  aalllne  salts  of  dtolilopoacotic  and 
tTicliloruno.-tic  ut-ids. 

TliU  pliKUouiuiiou  twn  be  ccpl&iued  by  tho  nfisuniptiou  that  aniline 
salts  are  decomimsed  into  free  nc^id  nnd  nailliio  wlieii  di&solTcd  ia 
aniline,  in  a  manner  Himilar  to  tho  BeliiTif;-frea  of  miUa  fruui  their 
nAti;r  orcrystblliiHtticin  wlicn  di»aolvi^  In  wiitui-  aiii]  by  I  he  further 
aHMiiiiiiiinn  lliat  (lie  Gl;glit  ionization  niiderguno  by  Ww  fn-o  iickd  la 
thomiilinu — such  solutions  being  vt-ry  poor  conductors  of  tbv  cloclrio 
curmul — is  jjruporLioual  to  tli0  di-gruu  uf  jouixatioo  in  iiquiwus  so- 
lutioo. 


2.  Diazonium  ttalts  unite  wit!i  tertiary  smioeH  at  the  para-po^ 
tion: 


3.  They  react  similarly  n-ith  phenols,  furniing  hffdroxyaso-cma- 
poumta.    This  lakes  placo  ia  presence  of  alkalis: 


C.H,-i\,-iCl  +  HJC^.OH 
rbMioi 


C,n*->-':N-C«H,OH  +  HCl. 

UjdrcixymKibeajEs  ih 


A  nurn>)or  of  important  dyes  are  also  derived  from  fit/droxy^] 
azobmsaie  (322). 


n.    HTDBAZIRES. 


805.  TTic  most  important  derivative  of  liydrazine  is  phenyU 
hydrazirip,  Cnllj-.MPNH,.  whinVi  bas  Wen  refurrwl  to  several  times 
in  the  fatty  5«rJes   in  connectjoa  with  its  action  ou  alduhyilea, 


PHENYUIYDRAZINE. 


403 


ketones,  and  sugars  (11 2, 208,  ami  212.)  It  U  formed  by  the  reduc- 
tion of  thi-  dlazotiiunt  salts;  for  example,  from  betut«nediasomum 
chloride  by  tlic  at-tion  of  the  calculated  quantity  of  etannous  chlo- 
ride dissolved  in  hyitroehlorie  at;id; 

C,Hi*Ni'a  -I-  -IH  -  C,H,-NH— N*H,-HCI, 

It  can  also  be  formed  by  transfonuhig  the  diaKoniuni  salt  intn  a 
diaxosiilphonal*  b_v  means  of  alkali-suipliilH,  reducing  the  dia;tmiil- 
phonatc  nith  xinc-tlust  and  ac<*lic'  acid,  and  splittiug  i>ff  the  sulpiiu- 
group  by  boiling  with  hydrochloric  acid: 

I.  C,Hj-N,-C!  +  NarSO,  =  C,H,-X:N-.SOj.\a  -1-  Naa 

Bndluiri  cllaiobvnK^MHllplienllU 

n.  CA'N:N-SOj^a  -f  2H  =  C„H;-XM-XH-SO,ya. 

Sodliiiii  I>h^nylbTlJnkIlamlipboIla■« 


nr.  Coir,'NH-NH-SO^a+H,0 


C.IIsNlINmj-f-XaHSO.. 

Ptit-i)fliiydr«iliM 


k 


Thie  apparently  roundabout  way  in  Bimplc  in  practice,  since  the 
intormciiiatJ?  proibmts  (lt>  not,  no«l  to  be  iKolatnl.  It  i,s  suflidoni  lr» 
mix  tlir  .solution  of  the  diaxonlitni  salt  with  that  of  t\\v  f.\\\\t]nW, 
then  to  add  the  acclir  arid  and  j;inr-<lu«t,  and  filfor  off  tJie  excess 
of  the  latter,  Thr  iiltrnte  is  then  bi)il(<l  with  fuming  hydrochlnric 
acid,  whcr(!ii[M>n  the  hydrochlorid**,  (.-gi^li'.MI'.Mlj'iK'l.  sfparatcs 
out,  since  it  i«  soluble  x«th  diflieulty  in  water,  and  almost  itisoluble 
iti  hydroehloric  acid. 

Phenylhydraitine  is  a  colourless,  oily  liquid,  tnndng  brown  in 
the  air.  Its  melting-point  is  I7'5*,  and  its  boiling-point  241°; 
when  boiled  under  onliiian-  prc«anre,  it  imdcrgCM-s  tiligbt  decompoai- 
tion.    It  is  only  slishtly  soluble  in  water. 

I'henylhydrazine  is  split  up  by  ^nerRPtic  reduction  into  aniline 
and  ammonia.  It  is  ven."  wnsitive  townnis  oxidixiuji  agenls,  its 
sulphate  iKinp  oxidixed  tn  the  dliizoniuin  siilt  by  niiTcury  oxidp. 
Oxidation  usually  gora  further,  however,  the  nitrogen  being  elimi- 
nated from  the  molecule.  I'or  fxamplc,  an  alkaline  copper  solu- 
tion converts  it  into  water,  nitrogen,  a.n<\  benzene.  Fhcuylhydra- 
zinc  has  n  wholly  ba.sic  character;  it  yidds  well-defineil  crj-stallino 


404  ORGANIC  CHEMISTRY. 

Phenylhydrazine  is  proved  as  follows  to  have  the  constitutional 
formula  CaHj'NH'NHj.  A  secondary  amine  is  converted  by 
nitrous  acid  into  the  corresponding  nitrosamine: 

C^-N<Hj,-C,H.N<NO. 

HonometbfUnillDe      NltraaometbjIaDUlne 

On  careful  reduction,  this  substance  yields  melhylphenylhydreusme, 
CBH(N*<pjr',  which  can  also  be  obtained  from  phenylhydrazine 

by  the  action  of  sodium,  one  hydrogen  atom  being  replaced  by  the 
metal.  On  treatment  of  this  sodium  compound  with  methyl  iodide, 
the  same  methylphenylhydrazine  is  formed: 

C,H,NHNH, -.  C,H,N<2^ -^  CJI,N<^. 


COUPOUNDS  COVTAXKINa  A5  UNSATUKATKD  SISE-CHAIS. 


Hydrocarbona. 

WW.  Stiirolf,  C,n,-CH:CH^  which  derites  its  nrnno  from  its 
occurrence  in  storai,  c«n  be  obtained  hf  tieiiuiig  oliinamic  acid. 
C,IIj-0n:CH.C0Oir,  which  spins  off  CO,.  it  is  n.  liquid  of  ftsrce- 
al))e  cidoiir.  nnd  lioils  al  UR',  It  is  mm <TleiI  nii  lieatjiig.  and  also 
slowly  oil  siniidin^  «t  ordiiiJiry  i»'inpi.>rnl Hres,  intra  a  ^lasa  like  mn»a 
called  met asly role,  »  polymer  of  niiktiown  innleciilnr  weight.  Sljrole 
bns  ilie  power,  chiimcUTiBlie  of  siibsluni;«'a  oontAiiiin;  A  double  bond, 
of  formlti?  ftddiiion-iirodiicls.  On  treRrmeiit  with  iiliric  nciil,  it. 
jiifHt  nitrastyrote.  C,II(('iI:Cn-NO„  with  llift  nlrogtonp  in  (bo 
fttdu'Clmin.  Tho  i-unntiintinti  ot  iMh  omiMxind  follows  rrom  ita  fortna* 
tioa  by  the  condt-n^tinn  "f  brnz.ildchydo  with  nitrometbaue,  under 
tbe  cMalyiic  influence  of  lUcobolic  potnsh  : 

C«^'-*-"|b"TTl.iCH.NO,  =  C.»*Cn:C'K.NO.  +  H.O. 

Phmylaettl/ime.  C^IT,  C  *,  CR,  can  be  obtaine<1  by  trpaUng  teoto- 
pbmionc  wilii  idiosphnnis  pentncblarido,  and  nrtinicoii  lliu  rctmltipg 
oompoiiTKl.  (_',H,  COIj-CH,.  with  oau»tjcpoi»sh:  or  frwni  jihmijlpropi • 
olic  ficid,  C|(lj  C  ;C-C00n.  by  nlow  diitlllnlioii  with  Anitiiio.  In 
roitny  rcspectiS  it  rDsembiM  nceiylcnu,  ylcMing  mctnllic  derivatires,  for 
exampie.  On  solution  in  coiiccntrntcd  sulpburio  acid,  it  titkoa  np  one 
mol«cLle  of  w&ter.  (nrming  aci-topheiiona. 


AUoholi  B.nd  Aldebydet. 

807  Cinnnmie  alcohol,  C'^H,  cn  :CHCH/>H,  \%  the  only  repr». 
aentotiveof  liii:*o  alcohoU  which  need  he  iiienlloned  here.  It  is  n 
crysIalliTio  Buhsranec  wiiU  nn  odour  of  hyacinih*.  nnd  1«  pmirnt  m  An 
estCT  ill  slornn.  ('artful  oxidnlion  conv^rU  it  iatocinnamic  acid,  nod 
mors  vigorouit  oxidaiion  inta  benxolo  noid. 

S06,   CinnamaUlthydt.  CJI^  Cn:CHCg,  ii)thechi«r  cODeliiu^nt 

of  oil  of  cinnamon,   from  which  it  can  bo  obtained  by  uieani  of 


4o6  ORGANIC  CHEMISTRY. 


• 


tt«  au1pbit4  compound.  It  is  an  oil  of  aKre«abIe  odour,  and  twils  at 
246*.  Ic  is  re<titiifl«l  by  ilmng  aoidn,  nnd  <rielila  a  oompound 
^]((-«II)^U|)i  <''^l)  aimnonia,  iu  tho  s4imu  wiiy  u  Wasaldefajde  (9W>. 

Acids. 


309.  Of  these,  n«na»JiVaftW,C,Hs-CH:CH -coon,  is  the  most 
iinporliuU.  \t\s  |)ri-s('iit  in  sniiipl]at»Lms,and  instorax.  It  is  manu- 
fac'Liirud  by  a.  synthetic  melhml  (liseovt-reel  by  W*.  H.  I'ebkis,  Sen. 

BeiiialdeliyJc  is  hcatwl  with  acetic  auhydridc,  in  presence  of 
sotliuni  acetate  us  a  catalytic  ogiMit : 

C,H,cJJ+HjCHCO  O  CO  CH,'*C,H,CII:CH0O'OCOCH,+ 

HeuxaUebjril'i  Awlli-  nuhj-driila 

+  H,0  -  C,Ht-CH:CH0OOH  +  HO-CX)-CH,. 

Chitwnilc  Kill  AcmJc  Mdd 

Perkin's  synthesis  can  be  carrietl  mit  wilS  aubetitutcU  bcnz- 
aldehytlcn  on  the  one  hand,  and  with  homologues  of  acetic  acid  or 
with  dibasic  acids  on  iht-  otIuT,  so  that  it  in  piwsible  to  obtain  a 
great  number  of  uusaturaicd  aromatic  acids  by  its  ait). 

OinnniDic  ncid  cAn  aIso  boobtmiicil  by  the  nction  of  bvtixnl  cUlnriilo 
^Sllj,  CjlIj.CllCI,.  [i|«)ii  sudiiim  ncvlule.  It  ciiii  furlUor  bo  syoibo- 
iicod  bj'  l)i(d  con<]t:<ti6ittion  of  makinic  &cid  uilti  beiixuldohyde,  wbtcli 
takes  placB  KEdiljr  uiiditr  tho  catHlylio  icBnoaco  of  ammoQiit.  ou« 
molecule  of  carbon  dioxido  bciDg  splil  off: 


llklaiileacM 


rCSnnamic  acid  ia  a  rrA-xtalllne  substance,  melts  at  131*,  and  di*- 
aolvea  ivith  dillifully  in  wltl  water.  In  all  respccte  it  posSKSftes  thn 
character  of  u  substance  with  a  double  bond,  and  thci^ore  foniis 
a<Idition-productJt  and  reduces  Baeyer^  reagent  (188).  Its  con- 
stitution indirates  tliat  twu  slcivuisoiners  are  pussible: 


C,Ha-C-H 

H-C-COOH 


and 


C,1L— C-H 

cooH-0— n 


An  isomer,  oHocinRamic  acid,  is  known;  it  is  readily  transformed 
into  unltnary  ciniiauiic  ucid. 


POLY-SUBSTITUTED  DERIVATIVES  COHTAINIirG 
SIMILAR   SITBSTITTTEHTS. 


310.  Tlie  number  of  poly-siibslitiitrd  dprivativca  of  benzene 
and  ils  honiologiH-s  Is  vpry  grrnt.  The  hydrogen  atoms  of  these 
hydmcarbons  ran  be  rc-plarnd  nnt  only  by  two  or  more  amilar 
groupfl,  but  also  by  two  or  more  ilifforrnt  gn>iips.  For  rach  liiwib- 
st it ution- product  and  for  each  irUubstitut ion-prod uet  of  beii^en* 
three  isninors  arc  possible  when  the  siibstitucntu  ar*  similar.  In 
the  homologues  of  benzene,  substitution  can  take  plaw  wholly  or 
partly  in  the  siiie-cihain ;  thus,  the  following  isomers  arc  theoreti- 
cally possible  for  a  com;iH>imd  C,LI/^I,: 


^^       cai 

(5) 


a/~~\cii,       ci/~^H, 
ci  ci 

(2)  C3) 


ca 


(4) 


CI 


a 


H, 


CJ  (^ 


(6) 


(7) 


^ 


tS) 


(9)  (10) 


A  large  proportion  of  the  niimerous  compounds  thoorelically 
possible  is  kno*-n.  Only  a  few  of  the  chief  of  them  ran  be  consid- 
ered here. 

It  would  be  impossible  to  lic^crilx!  for  carh  of  these  compounds 
how  thepoffltions  of  ils  subetiluciit^  {oriental ioji)  has  bwn  deter- 
mined, so  lliot  a  summary  ttill  be  given  of  the  methods  of  orien- 
tation in  352  to  3fi6. 

40J 


4o8 


ORGASIC  CHEMISTRY. 


I.    rOLTSUirKORIC  ACIDS. 

Stl.     When  b«DE«ne  and  iia  hvmuloKues  are  treftt«d  vith  fuming 

lUlpfaDrie  will,  duul^ihonio   »nil  iruulfilioitit:  xcide.  twj  similMr  in 

prop«rtie«  to  the  Biono^utphonic  &eiA»,  nrt  fortued.     Cntler  thU  ircat- 

nwnt,  b«uieii«  yields  m^flUttipfio/iK  acUl,  whicb.  on  prolougMl  liraliog 

9  partlnUy  convertod  into  tho  jHtutiiphonic  aeid. 


II.     POLYHALOOEH  DBBIT&TITXS. 

312.  ThpBp  can  Ije  nbtainpii  by  the  dirpct  actinn  of  ohiorine  or 
Ijroniinc  iipim  tin-  nninialir  hydmrflrhons.  If  one  lialoKcn  atnni  is 
already  prrsrnl,  5iiI)ntLtiiti[>ii  takrs  place  principally  in  the  p-posi- 
tion,  a  smaU  quantity  of  the  fl-cnmpound  being  also  formed.  m-Di- 
chiortihemtnt  or  m~<iibromr^(nzent  is  obtained  from  »^d^nitPoben,- 
stcnp  (318)  hy  reducing  to  dinmine  and  subscciupiilly  diazotizing, 
3l  has  bifen  found  possible  by  prnlnnRwl  halogenalion  to  replace  the 
rix  hydrogen  atnms  of  henzpne  by  halogen,  C,CI,  (JuLixs'  chloro- 
■cnrhon)  ig  thus  obtained  in  the  form  of  roIonrlcM  needles  meking  at 
229*.  h  has  not  hr-cn  pafisibl«  to  replace  all  the  hydrojwn  atoms 
in  toluene  by  chlorine;  it  ha«  ouly  been  coaverted  into  Ulra- 
<filorobfraotrkhloride.  CjHCl,'CCl,,opinti)  pcntaefiloii^>auat rMoride, 
C,CI,'CKCIj.  On  further  clilorination.  the  moleeule  spiit^  up. 
Examples  of  this  phenomenon  are  alwj  found  in  the  fatly  series. 

The  same  nieih'ods  can  be  einployed  in  the  prepaiaiion  of  the 
polyhalfigen  derivatives  of  the  honiologues  of  benzene,  at  have  been 
described  for  the  monohalos;en  deiivatives  (273)>  If  it  i-a  desircil 
to  Kulutituie  in  toluene  the  nielhyl-hydmgen  atoms  aJnnc,  thi« 
hydn)carb(>n  is  treated  with  chlorine  or  bromine  at  tlie  builirtg-fxiinl : 
there  are  obtained  in  succession  btnv/l  chtnride,  CHj'CHjCi.  henznl 
chloride,  O.H/CHCI..  and  benzolrithloridc.  C^H^-CCl,.  When  the 
object  is  t4>  siibstitu(«^'  Liydn^gt-n  only  in  the  liog,  chlorine  iaallon-cd 
to  react  at  ordinary  temperatures  iu  presence  of  a  trace  of  iodine. 
To  prepare  n  ennipoiin<l  siifh  as  CoH;CI'CH,Cl,  both  methods  mu«t 
be  employed  in  Micr!P-'i.''ion. 

Benzal  chloride,  C,H^CHCi,  (B  P-  206'),  and  benzotriehloride. 
G.H,  CX'i,  {B.P.  213°),  are  of  technical  iniiHirtauce,  benzaldehyde 
(289)  is  obtAinoil  from  the  fonncr,  and  Itensoic  acid  (396)  from  t-ho 


latter. 


B4Dieaft«nd  Home  o(  its  hoino1ogi]«s  nlao  yi«ld  addition-products 
With  cblorina  nnil  bromine.     From  lieiiienu  is  obtained  beniene 


DIHYDfUC  PHENOLS.  409. 

chloride,  C,H,CI„  and  bemene  hexabromide,  C,H»Brg.  Both  nro  ob- 
tained by  treating  benzene  with  eicess  of  the  halogen  in  presenoo  of 
Bunlight;  the  chlorine  derivative  is  known  in  two  isomerio  forms. 

nt.     POLTHTDBIC  FHEHOU. 

313.  It  was  stated  in  875  that  phenol  ia  miicli  more  readily 
attacked  by  oxidizing  agents  than  is  Ixmzeno  itself.  The  polyhydrid 
phenols  possess  this  property  to  an  even  greater  extent,  many  of 
them  behaving  as  powerful  reducing-agents  when  dissolved  in  alkalis. 

Sihy^ric   Phenoli. 

OH  1 
The  o-compoiind,  C,H«  j-jti  g,  catechol  (pyrocatechol  or  pyro- 

catcchin),  is  a  constituent  of  many  resin.*?,  and  can  Ix)  pn^parcfd  by 
fusing  o-phenolsulphonic  acid  with  caustic  jKjtash. 
^  Catechol  is  cn'stalline  anti  readily  soluble  in  watiT,  alcohrt], 
and  ether.  It  melts  at  104°,  Its  alkaline  solution  is  fir«t  tunned 
y  --^.^gi^een  by  atmcepheric  oxidation,  and  then  black.  Its  aqii<><>iiii 
^"^  solution  precipitates  metallic  silver  from  silver-nit  rat*;  solution  at 

ordinan.'  temperatures,  and  givi-s  a  gn-ffii  colouration  with  ferrie 

i  WH    1 

chloride.    The  monomethyl  ether.  C',H4<..j\  ',,.  w  cailwi  giutiacol; 

it  is  present  in  the  tar  obtained  by  the  drj'  distillation  of  i>v*:rh-  ' 
wood.     When  heated  with  hydrir»dic  acid.  guaiac(»l  yieldn  cate- 
chol and  methyl  ifxlide. 

Resorcind {resorcin).  or  m-(hhydrrjxyV?nzene,  ''tH«</|||  -it  '^^n 

be  obtmned  by  fiLsing  m-phenylenedbiulphonic  aeid,  C,II^< '^.'u  ■,, 

mth  caustic  potash :  this  L*  the  meihfKl  by  which  it  ui  manufacturrr'L 
It  yields  a  deep-violet  ctiouratinn  with  ff-rric  chloride;  brominf?- 
watCT  converts  it  into  trihromoregarcinol.  It  u*  a  «flouri*»LS.  cr^>tiJ- 
line  substance  melting  at  1  IS',  and  rf;adily  ^»luble  in  wafrr.  alcihol, 
and  ethCT.    It  quickly  turns  brown,  ouine  to  the  aeiion  of  th^  air. 

Qunurf  (hydiTMjuinone),  or  p-riihydroxy'r^rrtwrriT.  ::j:\'^  at  U/fi. 
Its  chief  characteristic  is  the  hjss  on  oxi  iari/.-n  <'•  •.■ki,  hydrr«^-n 
atoms  with  formation  fA  ipiiw/w.  (.\H/*.  316  .  -TJ<?h  ^  r^aJLy 
reconverted  into  quinol  by  Tf^vur.i'-T..  Tr.-?  t^vi^.^  n5'rK\  'd 
quinol  is  employe*!  in  phot'jgrap'r.y  :  r  -.'rx-    ■.'z-^s.ynftz.;  '/.  tt*T^ 


4tO 


ORGANIC  CHEMISTRY 


tive*.  With  ammoiiia  it  givos  a  red-brown  oolnuration,  due  to 
the  formatinn  f»f  rttmplex  derivatives,  like  its  isomers,  it  ia 
readily  soluble-  in  vatc-r. 


Trihydrio  Phenola. 


OH  I 


314.  Pyrogallol  (pvmgallir  acid},  C,H^)H  2.  is  obtained  by 

XOH  3 

healluQ  ffallk  acli!  (345),  CO,  b»'iiig  split  off; 

C,H,(OH)/C(K)H  =  (VI/OII),  +  CO,. 

tlallli' HL-lit  i'xriiKollul 

Pyrogallol  fonns  crystals  melting  at  132°,  and  is  readily  soluble 
in  water.  It  i«  a  stnniK  n-durinp-nfrriit  in  alkaline  Mtliition:  for 
example.  Jt  rapidly  iilwurijs  thf  usygt-n  of  Ihr  atiiKisjdicrf,  with  for- 
nitttionof  a  brown  colouration.  J'or  this  reosctri  it  is  employed  in 
gns-annlypis  to  renicue  nxygrn  from  mixturps.  It  U  also  iised  as  r 
developer  in  j)h<>tography. 

Am  1 

yhloroglucinol  (Bvmmetricai  trihvdroxybon2€no).C^,^OH  3, 

^OH  5 
is  formed  by  Fiinng  various  resins  T\Ttli  caMstio  potash.  It  w 
crystalline,  and  pivcw  a  deep-violot  eotouratiim  with  feme  oliloridc. 
A  remarkable  nynihcsi^  of  plduroglucinol  lias  been  diseovered  by 
liAKYKH.  When  aodiomaloiiic  ester  (166)  '^  heated,  three  mole- 
cules condense,  t^ilJi  eliminat  ion  of  three  inulecidcd  of  alcohol: 


COOC,H,- 


t\H,0|CO 
HlCSa       f.s-^  Hj— COOCjHj 


CO 
.— CN'aC 


3C^0H  + 


COOC,lI.-CXa  CNa-COOPft 
OC      CO 
CNa 


COOC^,H, 


TRIHYDRIC  AND  HIGHER  PHENOLS. 


4" 


On  acidifying  tliis  crincloiiBatkin-product,  the  wHiiuni  atonu  are. 
rpplareii  hy  hydrogpn,  witli  fonnutifm  nf  ph^nrixjlucnM^tricnrborylic 
ater.     When  this    substaiiCL*  is   fused    with   oaundr  potash,    tlie 
ethyl-rarboxyl-eroiips  ( — COOC,Hi)  arc  ahstractvii,  mid    replaced 
by  hydrogen,  phlorogiucinol  resulting. 

Phlurojclucinol  should  ihurtifure  lisve  the  ooDsliluUon 

CO 

H.U     CH, 

I      I     ; 

00     00 


Yn 


■H, 

in  other  word*,  it  ia  a  bczarnctlij'lcnc  in  nhiob  three  of  tlim  raotliylcne 
Ktoups,  =C'H„  hmvn  bwit  rcpliiwd  hy  carbonyl,  =C0;  U  atuxi,  Ihcm- 
fore,  bo  calk'd  trikttohframrUiijiritr  ]l  has  lieen  proTed  thxl  pliluro- 
gluciiiol  doe3  hehn.vd  as  thoiigli  ii  hnif  thia  coiiatitutioai  Ihiu,  with 
lhn?e  niftlcctile*  at  hydroxy  lam  inc  ii  yielOs  ii  trioxiiuu.  On  IIju  oth«r 
hnnd,  plilnroghicinol  has  lh«  charHCUT  of  «  phenol;  (or  oxaiuplu,  tl 
yiHds  A  Iriiicelale  willi  acetyl  ohloridt;.  Ir  nists.  iherefnre.  In  tvo 
t.tntoniDric  forms,  ag  n  hoxamoT  hylonn  dorivntivo  and  Ha  trUiydrozy- 
benxcni-: 

It 
\, 


HO 


OH 


hI<|>i„ 


OH 

This  is  a  mnnrkable  example  of  the  alt^ralion  of  the  positions  of  the 
Atoms  ithu  liyilro(i;«ii  of  th«  Oll-nr^ups]  in  the  molocuie,  resultiUK  >n 
the  convenioii  of  u  benzene  derirntive  into  a  derivative  of  Iiexa* 
methvteno. 


Higher  Phenola. 

315  The  chief  of  these  is  heMilii/flr»xjiit)U«n«,  C^'OH],.  whoee 
potatsium  derivative,  potassium  oarkmyi,  C.rOR),,  is  fonDed  in  (he 
}>reparation  of  potasaiuia,  and  develops  no  cspluivo  ehAracwr  on  ex- 
posure to  llic  :iir  ("  InorgADlu  l.'hLt»i»lry,'*MTj.  It  can  be  oblalned 
by  henting  poinsslum  In  n  current  nf  airbon  (nonoxl(1r>,  n  ilinvet  syn- 
theaid  of  a  dcnvai  Ivl-  of  bcn/nii-.  Pimiiluiion  vilh  ziiii'-tliist  coiiTcrts 
tesahyilroiybcn/i.-nn  into  bi^nKi'nij.  It  \i  a  while,  cry»lAlline  KulMtaiioe, 
and  undersoca  oimaiion  vcr}  rcadiiy. 


4" 


ORCMWC  CHEMiSTRY. 


IT.    QDIHOItES. 

916.  Thtt  quinonts  are  gutjstaiicL>s  dorivod  by  the  eliminalion 

of  two  hydroxj'l-hyiirogen  atoms  from  aromatic  dihydroxy<lcriva> 

tives: 

CJT.(OH),  -  2H  -  C,H,0^ 

Thp  simplest  <|iiinonp  is  henzotjuinoTie.  r,n,Oj,  and  is  generally 
rallrtl  quitwne.     It  ie  obtained  l>y  the  (ixiiiiilitm  of  many  p-tifTivii- 

tJvTS  of  bensenr,  such  as  p-aininopiiool  C^,<\|.'  .,  sulphanilic 
Mid,  C,H,<^j  V,  .,  and  p-phonolsiilphonic  aci<i,  C,H^<j^  jj    y 

and  aUo  by  the  oxidation  of  aniline  wit  h  chroroic  acid — tho  ordinary 
nu-thud  of  prp[mratioD.  It  is  (Um>  fonncd  by  the  oxidation  of 
quinol  (,313),  though  the  laiter  is  usually  prepareil  by  the  re- 
duction of  <jiiinone.  The  two  other  ilihydroxj-benzfnes,  (m-  and 
0-)  do  not  yield  quinones  on  oxidation.  Tlus  property  is  possessed 
only  by  }>-dihy<ln>xy-i)€Tivativcs  of  benzene  and  xia  subetitutinn- 
producta,  and  by  higher  phenols  contaimng  Oll-groupe  in  the  para- 
puKition. 

The  riulnones  have  iimially  a  yetlov  colour,  and  a  peculiar,  pun- 
gent odour;  they  volatilizf  with  ateatn  mth  partial  decomjxisiiion, 
and  have  oxidizing  properties.  The  coustitution  of  benzoquiuone 
is  best  expressed  by 

CO 

HC       CH 


^ 


Such  a  formtila  requires  that  Ix-nzoquinone  should  be  a  diketooe, 
nndrontaiii  two  double  bonds;  its  pnipertlfs  show  that  it  docs  both. 
lt:i  kctonic  cliaraclcr  ia  inferred  from  it«  yielding  with  hydroxyl- 
omiiic  first  a  guincne  moMzinu,  and  then  a  ^inotu  dioxime/ 


C=NOH 
HC      CH 


and 


C-NOH 

HC      CH 

il       » 
HC      CH 

C=NOH 


QUSNONiS. 


4'3 


The  presence  of  double  bonds  is  proved  by  its  power  of  forming 
additiou-products;  benzoquinone  Id  chloroform  solution  can  tiUce 
up  four  atoms  of  bromine.  Accortling  to  this  oonstitution,  Ixmzo- 
quinone  is  not  a  true  benzene  derivative,  but  the  p-diketoite  of 
a  dlhydrobeDzenc; 

CH, 

/\ 

HC       CH 

The  forrnfttion  of  benzoqiiinone  from  quinol  is.  another  example 
of  the  conversion  of  ec-iilriL-  bonds  into  double  bonds  when  two  of 
the  former  disappear  (270); 

C-0 

HC/NlH 

\)H  C=0 

Some  apparent  exceptions  to  Uaber's  Bchemc  [292)  for  the 
electro-reduction  of  nitrocompounds  may  be  mcrtione<l  here,  be- 
eauac  they  are  cxplaineil  by  aasuininK  tlial  iiuirmiic  drrivativcs  are 
formed  OS  intcnnediate  products.  The?*'  exceptions  havii  Ijcvn 
observed  in  the  reduction  of  hij^her-aulistitutpd  ritrobcnxenc  <leriv- 
Atives  in  alcohol if-alkaline  Holution.  According  to  thp  srhpmr-,  azn- 
derivatives  shnul)!  Ih'  the  chief  pri»dut'ts  under  tliese  ciituiitioiis, 
whereax  it  in  found  tiiat  in  sonic  inslunces  amincit  an-  prine-ijiiilly 
prxMhicifl.  Thus,  ilic  main  proiluct  obtained  from  p-nitniiiilinr  i<t 
p-plienylfiKiiiuniinc,  whili-  under  the  same  conditions  m-nitrtuiiline 
in  a  normal  manner  yields  m-dianiinoastobfnBPno.  This  difference, 
however,  is  rradily  explainud  by  the  fact  that  p-nilratiilinp  gives 
rise  to  (jiiinone  derivativt-s,  whereas  vi-nilratiiliiie  d<K«  not;  tin 
reduction  of  p-nitraniline  to  the  corresponding  hydroxylanmie,  the 
latter  readily  splits  off  one  molecule  of  water,  yielding  quinonc 
di'iniidc: 

NH,-C,H/KO,  -  NHj-CJI/XrrOH  -  Mr:fVI,:  Nil; 

ti  ViimnlliriF*         f--Vniluc>|ih»')*jrlhjfiJr"iif  limine       yu»iiiiiiu  tli>iEjild« 

and  the  l&ttcr  in  readily  retluced  to  ;>-plienylcnedianiine: 
NU:C-,H,:NH  +  2H  -  H,.\'-(J,H/XH,. 

^•I'tlrll>  loilnllAIIIIDK 


4(4 


ORGANIC  CHEMISTRY. 


m-Nitruiiilinc  is  unable  to  form  a  <(uinunc  ciRrivative,  and  is,  there- 
fore, reduced  normsily  in  ftccorrlance  with  the  scheme 

TetnKh}oro<iiitni>ne,  or  chlornntl.  C,Ci,0,.  \*  oblflitK-d  by  the  ao-'J 
tioii  uf  chlorine  i>n  etui  none,  and  iiino  by  thU'UXifhiliuiiofiniitty  organl 
8Ubstnnu(«  with  liydroclilorii!  ncld  mid  potAHSiiim  cblorate.     It  Eornu 
yellow,  glistening  k-uvm,  ni\<\  is  nn  oxidizLRS-ageiil. 

817.  Pontamothyl^ne  yjoliis  r^markAble  quimmoji.  obtAiacMl  by  th» 
oxidation  of  hexnhydroxylciiKcno  in  nlknlinc  Hultiiion.  Among  them 
U<:roeoiiic  add,  CjlI,Oj,  which  has  an  intcnae  yi>l!o«"  ootour,  ftod  Is 
convuru'd  Ijy  wwik  ri^iliicinK-ngiiTits  iiiio  a  colourltvu  subatancc,  from 
wliifh  eiviooTiic  fict'l  onii  bo  oblalncti  hy  oxidntlon.  On  oxidnlion, 
croconic  uuid  ia  trnnfiruniiud  into  Icuconia  add,  C|0(  -f  4B)0.  ThU 
eompautid  has  tho  consti union 

CO -CO 
Oc/       \C0  +  4H,0, 

ilnc«  it  yioMs  a  pontoximo  or  th«  fnrinulii  (C:  XOH],, 
V.    POLTNITBO-DEBIVATIVEB. 

S18.  m-Dj'ni'/rotenzfnf  is  obtained  by  the  nitration  of  benzene 
with  a  mixture  of  codceDtratdt  sulphuric  acid  and  fuming  mlric 
acid;  it  forms  rolniirlests  needles  melting  nt  00°.  On  reduction,  it 
yields  ni-phtti'/fcncciiamine,  and  is  on  this  account,  employed  in  the 
preparation  of  aniline  dyes;  it  is  also  used  in  the  manufacture  of 
exploKiVL'g,  since  it  can  be  exploded  by  merciin,'  fulininato.  In 
addition  lo  the  m-conipciund,  sniull  iiuaiititii'S  of  o^tniirobenume, 
and  traces  of  the  fy-iienivtit-e  are  formed.  On  stronger  nitration, 
effected  by  a  mixture  of  nitric  and  fuming  suljihuric  acids  at  140", 
m-dinitrobenzcne  is  converted  into  sifmmeincal  trinitr 
(1:3:5),  which  mcH«  at  121*. 

The  hydrogen  atoms  and  nitro-groups  in  the  polynjtrobenzenee 
are  much  more  readily  replaced  than  those  in  mononitroljenzenG. 
Thus.  wj-dinitroljeri7.enc  is  converted  hy  oxidation  into  dinUrophmal, 
and  trinitrobcnzcnc  into  picric  add,  or  trinitrophcnol ; 

NO,  NO,  NO,  NO, 

TJO,       ^^O,  ^JO,  NO, 


POLYmTRODE/UyMTifES  /IND  POLYMMINO-COMPOUNDS,   415 

By  the  notion  of  sodium  ethoxidc  anil  methoxide  respeelivelj-, 
one  of  the  tiitrogroups  iii  o-  and  p-dinitrobpnxeJie  can  be  quanti- 
tatively replaced  by  OC,H,  and  OCH,: 

C„H,<-;;^  +  NaOCH,  -  CJR,<^^*  +  NaNO^ 

It  is  remarkable  that  this  fcubstitution  docB  not  take  plaee  vritta 
m-duiil  robetufiw. 

When  boiled  with  caustic  soda,  o-dinitrobenzeiie  yiulds  niiro- 
phenol,  and  when  hi-at*d  with  alcoholic  ammoiua,  nitranitinc: 

;N0,  i+NaOH  yOH 

C^,< NaNO,  +  C,h/       . 

XNO,  2  \nO, 

n  H-  ^NO,  1  -J-  HXHj  _  ,.  „  ^NHj  ,   ,„.,. 
^""«^N0,  2  '"•"*^N0,  "^  ^^^^»- 

TrinitriAufi/lxi/hiii;  coalHinlng  a   [ertmry  liutyl-groui).   bun    an 
odour   rcsombhn^  musk.     It   u  sold    under   the    iiiLni«   "ftrtlflclAl 


TT.  POLTAHIXO-COHPOtTHDS  UTS   THEtB   DESITATITEB. 

819.  Theap  are  obtainrd  by  the  n-duntion  of  pnlynitro-derivo- 

tivca.     m-Pheniflenediamine,  C,H,<».tr'  ,,  is  got  from  benzene  by 

nitration  and  sul(si'<]u<'nt  riiluction. 

The  p-dcrivaiive  can  be  prepared  by  the  reduction  of  amino- 
azobon>!etie  (304)  with  Lin  and  hydrochloric  acid,  ajiiline  and 
p-phenylenediainine  I>fiiig  fonnyd: 

+  H,.H, 

OrtA^Mliamino-com pounds  react  readily  with  l:2-diketone9, 
yielding  (luinoxaliTiea : 

-    (      ]        T        +2H,0. 


H,  0 


Like  the  polyhydric  phenols,  the  polyainino-eompounds  are  veiy 
readily  oxidized.  Tbey  arc  coIoOrless,  but  many  of  them  arc  turned 
brown  by  oxidation  in  the  aJi. 


41 6 


ORGANIC  OfEMISTRY. 


Au-dyu. 

320.  The  azo-derivalivpfl  of  the  polyamino-compounds  are 
known  as  ajo-rfi/c-8;  ihpy  are  or  great  teclinieal  unporiance,  being 
extoriMVcly  employed  in  ilyting  wool,  silk,  aiid  eotton.  Tbey  are 
asobeiiBenes  in  which  hydrogen  aloins  have  been  repUced  by  aiiiido- 
groups.  These  are  not  the  uiily  dyes;  derivatives  of  aiobenzcnc 
in  which  liydrogen  ia  replaced  by  hydroxyl  or  by  Uie  sulpho-group 
can  likewise  be  aaploycd  in  dyeing.  Some  of  these  will  also  be 
described  here. 

It,  Ls  finrt  npocssary  to  state  certnin  facts  reganling  dyes  in 
general.  It  has  been  pn)ve<l  by  experiimce  tliat  it  is  not  by  any 
means  evcr>'  colon  ring-matter  which  can  dye  the  eulx«tai)cea 
itaiiivd  aljovc;  that  ia,  colour  thtin  so  tliat  the  dye  cannot  siibtse- 
quciitly  be  reniuvid  by  rubbing,  or  wasliiitK  with  water  or  soap.  It 
is,  therefore,  ncccssarj-  to  make  a  distinction  between  eoloured  sub- 
stances and  dyes;  for  exampJe,  aKotjcnzene  has  &  dwp  yellowish- 
r«l  colour,  but  is  not  a  dye.  The  introduction  of  an  aniido- 
groupj  however,  converts  it  into  aminoaitobenzene^  which  is  a  dye. 
Witt  has  j>iit  forivanJ  the  theory  that  the  coU>uring-f)owrr  of  a 
Cf^Ripound  dcp(;ndi3  upon  two  fuc:tors.  The;  tinil  of  these  is  the 
presence  of  crrt-ain  groups,  which  he  e&Ms  ehromophons,  among 
which  are  the  azo-group.  — N^X — ,  the  nitro-proiip,  and  othcK. 
Subslorces  containing  a  ehroinophore-growp,  along  with  XH,,  OH, 
SO,H,  or  in  general  a  group  which  imparts  to  them  an  acidic  or 
basic  eharactfr,  are  dyee;  this  is  ilhistrated  by  amiiioazobenzrne. 
Another  example  is  nitrobenzen*-,  which  han  a  paic^yellow  colour, 
and  contains  the  chromophore  nitro-group,  but  i«  not  a  dye;  on  the 
other  hand,  p-iiit  raniline  and  p-iiitroplictiol  are  dyes. 

SSI.  ]n  iiinny  cases  it  is  sii9iuiE<nt  loimitii-rsu  I  ho  silk,  woAt,  orcoi* 
Ion  to  be  (Ijed  innsolution'of  the  clyo.  Binoc  it  wiu  dissolvi^  at  flnu 
bttt  cannot  bo  removed  by  washing  tbo  fabric  HHer  it  faas  boeiwlyi.'d,  ibr 
dye  must  linrc  imJrrgoiiu  u  cIiiiDgc.  It  is  iiMuninl  ttint  it  uniuu  villi 
the  coiiMitui-tita  of  the  aniinnl  or  vegctnbta  0br«:(  to  form  a  ootiapouiKl. 
a  kind  of  .salt,  Riiice  dyta  alnaya  have  a  Iwsic  or  ocldio  ctianictcr.  A 
proof  of  thifl  will  bo  given  for  rManiliae  (ifJ). 

In  other  cases  the  t»Me  ilnes  not  tiiko  up  the  dye  when  Immersed 
in  ite  solution  ;  it  hns  boeii  repeatedly  obserTed  that  dyed  which  be- 
come direrlly  flieilon  nDimnI  fnlirics,  etich  as  silk  and  wool,  do  nut 
dye  vt>)i<'tftb]«  fnbric^.  like  cuttoit,  tinlees  Iho  nalfiriid  to  bo  dy«1  has 
nndergiUMt  a  sjiwiid  prtK^ess,  called  mordatilhig  :  thnt  is.  n  Biilistnnoe 
muat  ^jo  HfpoKiK'il  iti  rbe  fabriu  lo^  the  dye,  siiwe  llio  laruT  u-ill  ttat 


AZODYES. 


417 


oniio  with  tbo  fibres  theTngvH-ps.  Such  siibelnnoeB  AN  OftUad  nmnlanUi 
th«y  kro  iisitdlly  salte  of  woivk  biuv«i  or  nckt« ;  la^h  WW  RlaBtinium 
acetate,  farrio  B^ils,  compounds  of  tin  ("pink  salt,"  3nCV  8NU4CI), 
Tlie  woieii  mttlerial  itt  tboruuKbly  soaked  iii  a  solution  o(  one  of  these 
•alts,  and  tlwu  sprt-iul  out  and  exiKAcd  to  ilia  uc^tion  of  ntfinm  nt  a 
euitablo  temperature.  The  tail  uodcrgoM  hydrolytic  dooompoaUion, 
and  the  base  or  aoici,  far  example  slumiiiium  hydroxide,  or  alnniiic 
acid,  u  deposited  Iii  a  Qqg  al«te  of  division  iu  Ibo  fabric.  The  dyo 
aaitm  vHh  thiH  baite  or  avid,  forming  an  insoluble  coupound  wbich 
>a  not  romovcd  by  waahiug. 

322.  Azim1}'(«  ore  (ibttuneU  by  treating  diuzMitiuni  chlorides 
with  aronmtjc  amines  or  with  phenols : 

CA•^^iMIHi<f~">^'(CHO,  =  C,Ha-N:N-C,H,-N(CH,),+  HCI, 

IlliuiauEum  cUoriJii     liJuMClif  luiilliui  UliuvtbykiiilitcibuuaiTaa 


C^-  N,  ja+51<^~\0H  =  C  JI,-  N :  N  ■  C,H.-  OH  +  J[CI. 

HTdraijrBiiibiniiR  ar 


when  l>asiiT  anrl  noidip  dyes  ari>  rrspetrtivply  prodiirrd.  It  was  mcn- 
tioiied  in  304  that  the  rDnihinatinn  of  a  dis7oniiini  chlnridc  »nd  an 
ammatio  amine  smnrtimcs  yields  the  diflzoamino-compound  as  an 
inlcnncdiatt-  product,  which  rait  l»r  wHivrrtrti  Int^i  thr  aminnaiio- 
drrivalivc  hy  vonninp  wilh  the  atiiiiic  hydnjchloridr.  In  lliia 
fnrmflliol)  of  aminnazn-pnni pounds  and  hydroxynzo-t-onipoundF, 
the  para-II-atnm  always  reacts  wnth  the  diazonium  chlorido;  when 
this  atom  is  replaced  by  a  siilM%titnenl,  the  formation  of  dye  either 
docs  not  take  place  or  is  verj-  incomplete. 

t23.  In  prcimring  hydroxyazo-dyca,  llm  solulioii  of  Lho  diaTniiium 
cliloridD  ia  kepi  vool  niih  ice,  and  is  slowly  added  to  the  alkaltne naiu- 
tion  of  tbe  pbcnol  or  iu  niilpbonic  ai-id  ;  caru  in  talEcn  to  keep  the  iv 
aelion-miximv  !iliL{htly  nlknliiu<.  etinco  nthcrwiso  the  liyilKiohlurlo  acid 
liberaliNl  w-uuh)  tiiiidci'  thu  forinntiua  uf  tb<!  dyi?.  After  (he  sotuliona 
haro  been  rtiisi>d,  itiv  dyo  it  "uilled  out  "  tjy  ttui.iildition  uf  t'otnmon 
salt,  vhicli  pTticipi intcs  it  iii  flocculcut  mnucs.  It  is  frvcd  from  water 
by  m«^ia«  of  fili(<r-praiwos,  and  put  00  the  market  ettbor  in  the  dry 
state  or  as  a  paste. 

Aminoazo-dyos  st\>  prepar<Ml  by  mlsln;  lho  aqueouit  golulion  of  the 
diaxciiiuni  cUlohdu  nilh  that  at  thc^iri^aiutioniniuoMiIt,  thccolouring- 
iiiatter  Iwiiig  Mib«u<)iii>nlly  enltvd  out.  It  is  Kutnutimes  iioowuary  to 
omploy  an  idcolinhc  soluiian. 

Tbesimpleat  nzo-dyesaroyi'llow;  on  the  iniroductJonoralkyU^roups 
w  pbeuylffroujifl,  and   iu  ^'envral  ou  iuoreiase  of  nioleciilar  weight. 


ORGANIC  CHEMISTRY. 


thoir  ^lour  changes  through  ornngo  nrul  rod  lo  violot  imd bine  Thvy 
arc  crysulli lie,  and  meat  of  tb«Ri  iiro  iosolublo  ia  water  ood  soluble 
in  alcohol.  Itisl^iid  of  tbo  axo-dyvft  tlietna«Iv«a,  it  is  often  be(t«r 
1«  vmploy  ihoir  stilplKniic  ucitls,  ubiainiil)l«  from  Ibem  by  the  asn&l 
in«tliod  — trcniiQctit.  with  concoutratml  sulphuric  actd. 

324.  A  sliort  *lct«-pip!ion  of  some  of  ilieeedyea  nmy  be  giv-cn  here. 
AnUin^ydlov!  is  a  salt  of  iiminoazi)b«'iuene;  it  is  now  Beldom 
uaed,  its  place  having  bwn  taken  by  oLht;r  j-cUow  dyta. 

Chn/aohline  or   diaminnaziibptiwne,  C^ij'N:N'C4nj<^|»',  is 

obtaiaed  from  bfiizeiicdiaionium  cliloriile  and  jri-phcnylencdianiinc. 
It  yjelda  a  Iiytlniclildridc.  crviitalliKinK  in  nwrdlcs  of  a  nxtdisb  colour 
and  fairly  i^uluble  tu  watc-r:  titb  salt  dyua  wuul  and  ailk  diructly,  and 
cottr>n  wiiich  hax  bwii  niordamc-d. 

Sistnartk-broum,     XHj'C.H/N  ;N-C9H,<;^-jj',     (triaminoazo- 

beniton^?),  is  manufactured  by  diazotiziiig  oiic  of  the  NU,-Broui 
in  77i<plir>ny|pnrrliain)iie,  and   lit-ating  tlic  product  Ibus  obtained 
with  a  sevutid  molecule  of  tliis  bas« : 


IICI  + 


.:<^xa. 


Nil,  NH, 

Even  a  rcry  dilate  solution  nf  nitrous  noid  gites  a  broum  oolonra- 
Uou  with  frcpbcDylttiicdiauiiDt,  due  lo  tbo  ronnalioii  of  Btsmarek- 
browii  or  n'hiuil  KulM^tnixioit :  lliitt  ivaelinn  furnishes  a  rery  delicaie 
twt  for  iiiiroiis  ncid,  mid  is  coi^^ivyud  in  vrntvr-aiinly«i». 

Hf^Jinthine,  or  dipioiUvliuninoaz(ibi'niiiJriPM|lphariip  Afitl^  is  pro- 
pnrcfi  liy  the  intpraelinn  of  bptuoiidliazoniiini  initphonic  add 
dimcthylanilinc  hydrocldoridc  in  atiueous  solution : 


HtyS  C,H/N,[OH  +  H|C,ll.-.\'CCJi,),  - 

-  HjO  +  HO,S-C«H,-N:N'C,H,-X(CH,)^ 

II  is  not  ofti-n  used  as  a  dye,  but  its  sodium  salt,  which  has  a  yeDnw 
oolour,  and  Is  turned  red  by  acids,  is  employed  us  an  indicator  in 
volumetric  atialyslH  under  the  name  jnelhyl'orange. 

Rt90Tvin-ytlf/w,   HO^CaH«N:NC,H,<yJJ,    (dihydrosyaio- 

bcnxenpBulphoiiic  acid),  is  oblainetl  from  tcsorcinol  C31S)  ojid 
bcniEcnediiLZoniurn  sulphanic  acid. 


PHTH/tLlC  ACID.  A^9 

The  diazo-dyes  are  split  up  into  aminocompounds  by  energetic 
reduction  with  tin  and  hydrochloric  acid.  Thus,  aminoazobcnzcne 
yields  aniline  and  p-phenylencdiamine : 

C.H.-N=N-C,H,-NH,-*C,Hs-NH,  +  C,H,<5;Jg|J. 

This  decomposition  on  reduction  affords  a  means  of  determining 
the  constitution  of  these  dyes,  and  indicates  the  nicthods  by  which 
they  are  obtained.  For  example,  Bismarck-brown  is  converted  bj' 
reduction  with  tin  and  hydrochloric  acid  into  a  mixture  of  equi- 
moleeular  amounts  of  diaminobenzouo  and  triaminobcnzene.  Since 
the  molecule  splits  up  at  the  double  bond  of  the  azo-group,  it  fol- 
lows that  the  constitution  of  this  compound  is 

NH,C.H-N:;X-C,H,<JJ2'- 

This  also  indicates  that  the  dye  can  be  obtained  by  diazotizing  a 
molecule  of  diaminobcnzcne,  and  treating  the  product  with  a 
second  molecule  of  diaminobenzene,  in  accordance  with  the  equation 
on  page  418. 

Til.  FOLYBABIO  ACIDS  AND  TEEIB  DESITATITEB. 
DIHAS1C  ACIDS. 
325.  The  dibasic  acids  arc  the  most  important  members  of  the 
series  of  aromatic  polybasic  acids;  they  are  called  plilhalic  acids, 
a  name  derived  from  naplitlialvnv,  from  which  one  of  them  can  be 
obtained.  Three  isomers  arc  possible,  and  all  of  tliem  are  known. 
Like  all  polybasic  acids,  they  yield  neutral  and  acid  esters  and  salts, 
acid  amides,  amino-acids,  etc.  On  distillation  with  lime,  they  are 
converted  into  benzene. 

Phthalic  Acid. 

Phthalic  acid  is  the  oriAo-dicarboxylic  acid  of  benzene,  and  hes 

the  formula,  ^•H,<™^,j,  „■    ^^  is  obtained  by  the  oxidation  of 

aromatic  hydrocarbons  with  two  side-chains  in  the  or(^o-position, 
or  their  derivatives  with  substitucnts  in  the  side-chains.  It  is 
worthy  of  note  that  chromic  acid  cannot  be  employed  in  this 
oxidation,  since  it  splits  up  or/Ao-derivativcs  (completely  into  COj 
and  HjO.  Phthalic  acid  is  employed  in  the  preparation  of  artificial 
indigo  (399),  and  is  manufactured  by  oxidizing  naphthalene  (370), 
C,oH,,  by  heating  it  with  very  concentrated  sidphuric  acid. 

Phthalic  acid  is  crj'stalline,  and  readily  soluble  in  hot  water, 


K^ 


,^.yr 


ORGANIC  CHEMISTRY. 


.O  A  itfkohol,  and  rther;  it  has  no  definite  melting-point,  since  on  heat- 
ijtf  (y  ing  it  splits  off  waU'r,  yielding  phtfialic  anhydride,  which  sublimes 
in  beautiful,  long  ncvJU-s : 

Ces—Or- 

326.  If  tho'  fnllowcd  the  onlinary  ruursc  of  the  reaction  form- 
ing acid  chluridt-s,  iihosphonLi  pentachloridc  and    phthalic    acid 

would  react  to  produce  a  chloride  of  the  constitution  ^'(H«<pJ^. 

That  they  do  not,  and  that  ph0)alyl  chloride  has  the  structure 

CCl, 

can  be  proved  in  varioiis  ways.     When  aluminium  chloride  reafitS^ 
with  fihllialyl  chloritle  in  presence  of  benzene,  tliere  results  a  com- 
pound nith  the  formula 

>0      . 

0 
called  phlhalophejume,  whose  ennstitntion  follon-s  from  its  formation 
by  the  elimination  of  water  fn)m  tri phenyl carbinolcarljoxy lie  acid: 


C,H  /  \o,H- 


X-OIOH 

Triphnnvlrai'lilrKil. 
carliuxyllc  uviil 


-K/)  =  C,H. 


\x) 


>0      . 


llitliBlophMioDa 


Another  proof  of  the  conslilution  iiidieated  above  for  phthalyl 
ehlnride  is  the  fact  that,  reduelnii-agenls,  such  as  sodium  amaljeam 
Bn<l  water,  or  zinc  and  tiydrucltloiiL-  acitl,  caiwe  the  replaocmcnt  »f 
its  halogen  atoms  by  hydrogen,  with  fonnation  of  phlhalide.     This 

-CH, 
substance  has  the  constitution  C,H,i      >0,  Binco  on  treatment 

XX) 
with  caustic  soda,  it  yields  hydraxymfthylhrnzoie  add ; 


^COOH 


This  proves  it  to  be  a  lactone,  and  not  a  diatdchyde,  C,Ht<  fiiiy  as 
would  be  cxpcctud  if  ttic  formula  of  phthalyl  chloride  n-crc 

327.  The  oxygen  of  the  carbonyl-group  in  phthalic  anhydride 
can  also  take  part  in  other  reactions;  thus,  when  this  substance  ifl 
heated  with  phenols  and  sulphuric  aciJ,  phl/uUeins  art?  formed: 

/C,H.OH 

H,o  +  c>H,<;    >0 


C,H.<f|L 


0  + 


W^ 


CJI.OH 
O.H.OH. 

I'boiiul 


ri>«iioiphiiMWii 


I 


mUiaJlcaiihjilrEilo 

Phaudphthnlcin,  thn  fiimplcst  member  of  the  phthaleiii  series, 
ia  a  yellow  powder;  on  account  of  its  phenolic  characttr  it  dieaolvcs 
in  alkaline  solutions,  with  formation  of  a  fine  red  colour,  and  is  a 
sensitive  indicator  for  alkali  tiic  try. 

Reteorcinol-phthnltm  or  flxumscein  Ja  charaetprized  by  thn  display 
of  an  intense  yirllowiah-grwii  Huortscence  in  alkaline  solution.  It 
owes  its  name  to  this  property,  which  affonls  a  delicate  lost  for 
phthalic  anhydride,  i)lilliulir  iicid.  and  iiMorcinol,  Kincc  fluorescence 
Ls  exhibited  by  tncrc  tracf»  of  lluoruact-'in.  It  ia  preparrd  by  heating 
■together  reBoreinnI  and  phthnlie  anhydride  at  210°,  in  presence  of 
xinc  chloride  as  a  d['hy<IratinK;-ajiPiit.  <>ii  trvatmont  willi  bromine, 
fluorescein  yields  tctrabromnfliKtresceiii,  whose  pota-ssium  deriva- 
tive, C,ftH,Br,0,K„  I'  the  beautifhl  dye,  tmin. 

niie  constitution  of  the  phthftlrins  is  infrrrerl  from  their  being 
convertible  into  derivatives  of  IriphcnyUnethane  (366). 


328.  f'hihalimide.  C^H^t^    >NH.  is  of  importance  on  account  of 

it»  application  by  (Jaiikiki.  Ui  l!io  synlhosis  of  primar>'  ninincs  with 
guhstitutpd  alkyl-gnnips.  It  is  obtained  by  passing  dry  ammonia 
over  heate<I  phthalir  jinhytlridi-.  The  iinido-hydrogen  is  replace- 
able by  melali^:  tluiH,  thi-  potassium  compound  is  precipitated  by 
the  ai'tioti  af  fau«tie  i>utush  upon  the  alcoholic  solution  of  the  imide. 
Wlien  potassium  phthtihmide  is  treated  with  an  alkyl  halide,  the 
mi*lal  is  replaced  by  ulkyl:  on  hcntinj;  with  aciils  or  alkallt;,  a 
priinarv  amine,  free  from  secondary  and  tertiary  amines,  is  split 
off: 


CHEMISTRY. 


yGO 

I<  >N 


ejl*<    >N|K  +  Br|C;.H„., 


®-h«<^nI  +  nh,c.h^... 


Variously  suhsiitutcd  alkyl  JialUIwf  caii  be  employed  in  this 
n-action;  thus,  from  ctiiyU-nL'  brotiijcle,  CHjUrCH.lir,  is  olitaiiiLii 
bromoethylamine,  XHj-CHjCHjBr ;  iwtu  Kliykocbromliydrin, 
CH,Br-CH;OH,  hydroxtjfthytamint;  \H,-CH,-CH;OH;  etc. 

Anntlier  nxniiiplc  is  ICuiL  Fisii»:hw  syt\\\\csm  nf  omUHine  (200). 
Putassitiiu  ptithuliniide  u  bruugbt  into  contact  wtlb  trinietbylene 
bruiuiilc : 


-CO 


e^<^.X>N|K  +  BrlCH,CH,CH^r 


.CO 


C,n,<^^>N-CHaCn,CH,Br. 


The  componnd  cbtauicd  is  treated  with  cthylsndiomatonate,  and 

yiclda  C,H,  <  ^  > N  'Cir,  •  CH, ■  CU, ■  CH(00OC,H()„  wliusc  icrliary 

hydrngrn  ntom   c-uii   be  siibKtilutcd  by  braniinc.     Saponification 
and  q>lltting  off  <»f  CU^  give 

G,H,<^>NCH,CH,-CH,-CHBrCOOH. 


Jy  heating  with  aqiieouB  anuiiunia,  Br  is  liuui  roplacwl  by  NH|. 
Subsequent  heating  with  concentrated  hydrocIUoric  acid  yields 
ornithine: 

G^<^>NCH,CH,-CH,-Cn(Niy -COOH  • 
+  20HH 

-  G.H*<S2^S  +  H^CH,GH,'CH,-CH(NH,)-eOOH. 

These  examples  make  it  eviricnt  tliat  this  method  can  be  ap- 
plied to  the  preparatJoQ  of  tbv  most  variously  substituted  primary 
amines. 


ISOPHTH^UC  MSD   rF.M-PHWAUC  ACIDS. 


•4*J 


39fl.  UoooewERPr  and  tak  Dorp  found  thAt  ammonia  reacU  with 
pbthalyl  uMoridc,  jieldiiig  o-cgaruArtuolc  acid.  C(H,<qqq|.;  it 
most  be  usumed  tbat  nu  iso-imidt  of  phtliallc  acid  Is  formed  as  an 


latcrisedlfttc  product : 


cliUirMfl 


c=Nn 


o,n,<'>  0 


CO 
Uo-lm.lde 


yCN 

x;ooH 

a-Cyanabctiaola 


Allbougli  tlioy  have  uot  been  ahlo  to  isolate  th«  iBO-iinide  tbelf,  they 
bnvv  pro))arot]  n  numl>er  of  UeiivacivM  in  which  tbo  imi do- hydrogen  ts 
replncod  by  hydrocnrbon-restdaes. 


liophthalic  and  Terephthalic  Acida.  C.ir,{COOTD,  (t;  S)  and  <1:4X 

330.  liffphthaUf.  tv^Ut  can  bo  obtained  by  the  oxidation  of  com- 
fwuiKls  with  [WO  Hidc-chaina  in  ibo  wirtn-posilion,  nnd  also  by  tbo 
oxidAtinn  of  r^in  (coloikhotiiuui)  uitti  iiitric  ociO.  It diasolvea  mth 
dilGculty  in  vaier,  nnd  does  notyJf<ld  na  anhydride. 

TfrcfihtTiaiic  acid  enn  be  pivpnred  by  so versl  methods;  fflrciAmpIei 
by  ihi-  oxidnliuii  »f  lurptintiiif.  !t  is  rilmo.u  insoluble  in  naler,  alcohol, 
Riiil  L'thur.  It  d'K'K  iiiit  iiK-U  timlcr  ilii>ordlnnry  prr^unni,  hi]l«t  high 
toiiiperaturi-5  sublimits  wiibouL  decora positiou.  Like  tho  iao-ocid,  it 
does  uot  form  an  juiiiyilndo. 

HIGHER    I'OLYBASIC   ACIDS. 

sat  Tried rboxy1i(!,  lotmcarltoxylic,  pentacarboxyllc,  and  hexa- 
earboxylic  n.e\t\<  iim  known.  The  inoitt  rfimnrkAblt;  U  tho  Ifuit,  mdliHe 
acid,  on  nccounC  of  it«  pi'oence  iu  lliv  miuiTiil  ttoney-ftone,  found  tn 
browu-coul  sesniA.  Uonuy-slono  \i  thu  nluiiiinum  Milt  of  aaollitic  Mid, 
and  \n\»  ihc  forinuU  C,.0„A5,  f  ISII,0:  U  forma  yellow  qii.idrfillo 
oclalii?dra.  MelliLiu  avid  m  prodiid'd  by  tho  oiidaOon  of  wood-charconl 
with  an  alkidiiie  solutjon  of  poi;ii<sium  poriDanfmnaie  iM).  It  oo'^i^l- 
Uzii»  in  Qne  needles,  aud  is  readily  solubls  in  water  and  alcohol.  On 
hoMiDg.  U  loses  tvro  molecules  of  carbon  dioxide  and  two  moleoulmoC 
water,  with  formatiou  ot  pgrvmeUitie  anhj/drid*, 

which  takes  ap  water,  and  Y\e\As,  pitromtiatie  acid,  C,H,(0001]),. 


DERIVATIVES   CONTAINING    TWO  OB  MO&E  DISSIIULAB 

SDBSTITUENTa 


r.  nTLPHO-DEEITATITM. 

EalogCD  Sdlphonio  Acidi. 

332.  Amon^  Uiesc  may  bi-  im-iitiuiirtl  the  three  bivmobeTuene- 

stdi^umic  adds,  iHi  of  which  yield  reflorcino!,X),H.<j^|r  -,,  onfuiaon 

with  caustic  potasli.  This  is  one  of  the  c»impsratively  few  cases  of 
substitution  in  which  the  substitutinK- group  occupies  a  different 
po^iliun  from  the  one  rpplapeil  by  it,  Othor  similar  e3C&mplea  will 
be  referred  to  later  (352). 

PhenolanlphoDic  Adda. 

383.  Oiiho-phmohulpliariir  anil  itg,Ta.-pht7iolsulphonie  acids  arc 
obtainod  by  dissolving  phenol  in  concent ralwl  sulplmric  acid;  ih« 
ta-arid  is  prYKlucod  wbtn  ni-bcrizcncdwu  I  phonic  nriil  is  fused  with 
caustic!  [KiIbhIi.  The  o-acjd  in  cljamcttTized  bv  bfiiig  readily  con- 
verted into  tlip  p-cf)mp«und,  even  <wi  evaporBtloti  of  its  aqueous 
sobition.  PIiciioI  i«  much  lutiff  n-adily  Milphonnted  than  beiuene, 
its  solution  in  Kulphurir  acid  In-iiiK  t mnsftrntird  intn  the  two  above- 
mentioned  acids  even  at  ordinary  tciupcTaturcs. 

rtPlionoUiiIphoiiTc  ftptd  is  emplnjed  as  an  siittiip[»i<e  unclar  thp 
nanifl  "(kve|it«],"  or  "wMtolic  jitid."  Pi-ifntopii/tatofsttip/ionie  add 
Is  also  tised  for  llio  Kame  p(ir|KMc,  under  the  nsmo  "MKtolodoL" 

p-Aminobenxenesulphonic  Acid  or  Sulphanilic  Acid. 

334.  Svlpfianilic  ucid  is  obtained  by  hcutiiiK  unitincwith  fuminf; 

milphuric  ocid.     I  jkc  its  isntncrs.  it  is  soluble  with  difficulty  in  cohl 

water.     Tiic  basic  prnp^Ttics  of  aniline  air  grpatly  wpiikcncd  by  the 

introduction  of  the  sulpho-f^oup  into  the  rinR,  for  sulphanilic  arid 

cannot  yield  salts  with  acids,  while  the  sulpho-group  reacts  \k\\\\ 

bases,  forming  salts.     The  fonnula  of  sulphanilic  acid  is  probably 

SO 
C«II«<»u*  >;  lliatis,  it  ia  an  iimer  salt.    On  fusion  with  caustic 

484 


SULPH/fNtUC  AOD  AND  SACCHARIN. 


4«5 


potaah,  it  does  not  yield  aniinophenol.  tia  might  be  ejcpected,  but 
aniline.  Oxidation  with  chromic  acid  converta  it  into  quinonc.  On 
pouring  a  mixture  of  eodium  sulphaniUtc  and  sodium  nitrite  In 
aqueous  solution  bito  dilute  !«ulphunc  acid,  an  inner  salt  of  itemene- 
diazomum  sulphonic  acid  is  precipitated,  as  it  is  nearly  insoluble  in 
water: 

This  compound  is  of  great  importance  In  the  preparation  of  aSo- 
dyesBUch  asA«/uinfAtn«  (324). 

SolphobeDzoic  Acids.  \ 

835.  Tbe  imido-dcrivative  of  o-sulphobenzoic  acid, 

luiown  as  saccharin,  is  about  three  hundred  times  u  BWect  as  sugar> 
and  on  this  account  is  8om(;tinie«  t'lnploytMl  as  a  substitute  for  it, - 
Direct  stilphniiation  of  Iwiizoie  acid  yit^lds  m-aulphoht-maie  aeut 
alnioel  exclusively,  so  tliat  saccliarin  cannot  be  prepared  by  this 
means.  Il  is  obtained  fnim  tolufiie,  which,  on  tn-aluivnt  with 
sulphuric  acid.yiddf*  a  uiL\luro  uf  f^-  and  o-toltceitcaulpftanie  acidt, 
the  f<irHivr  IwiiiK  the  chivf  protluct.  The  o-acid  is  converted  into 
its  sulplmmide,  the  mclhyl-p-ovip  of  which  13  then  transformed  into 
earboxyl  by  oxidation  with  potassium  permanganate.  On  halting, 
this  oxidation- product  loses  one  molecule  of  water  very  readily, 
forming  Mic<'b»nn: 

fkSiilpljHiiiidt-  lit  loT.inTi.'  bimI  SaruJisrlu 

Saccharin  is  a  white,  cryslalliue  powder,  soluble  with  difficulty 
in  cohl  watiT,  und  readily  Bolubk-  in  alcohol  and  ether,  1 1  takes  up 
one  molecule  of  water,  yictdinR  the  suIphamideoE  o-sidphobenzoio 
acid,  wliich  docs  not  powtes-t  a  swert  tnste. 

U.  BaiMEH    CEKIVATITES. 
Halof^en  ^henola 
336.  Orlbfw7i?nrop/i»-iio/  and   psrH-c/i/omp/ifTiof  are  formed  by 
the  direct  ctilorinatiou  of  phenol,  and  al»o  by  reduction  of  the 


42& 


ORGANIC  CHEMISTRY. 


balogcD  nitro-benzpnes  and  subBcqiient  cliazotization  of  the  com- 
pounils  formed.  They  have  a  pungent  odour.  Uy  fusion  with 
caustic  potash,  the  haUigpn  can  be  replaced  l)y  hydroxy),  although 
it  13  not  always  the  corrt'siMJiidiiig  hydroxy l-«jiii|M)UiHt  wluch  is 
formed.  Tho  inljiKluctiim  of  halogen  ronsiilcrahly  augmtrnt*  the 
aeidir  charartf-r  nf  the  phenols;  thus,  trichlnrnpheno]  decomposes 
carljonatcs.  It  was  inrntimirfl  in  276  that,  the  presence  of  hydroxyl 
in  th«  ring  corsidcrabiy  fa<'ilitat(w  the  substitution  of  Ihp  hydrogen 
atott].s  by  haloKPii.  Iodine,  however,  can  only  substitut*  ia  pres- 
ence of  an  oxidizing-agent,  to  remove  the  hydriodic  acid  formed; 
since,  uidess  this  were  oxidized,  it  would  take  away  the  iodine  atom 
froR)  iodophenol. 

Halogen  Benzoic  Acidi. 

837.  'Vhv  mH:(imp(nimi  ran  be  obtained  by  direct  chlorination 
of  benzoic  acid,  but  can  be  more  readily  prepared  by  diazotising  the 
corresponding  amino-rrnnpound.  This  is  also  the  best  method  for 
the  preparation  of  the  wrtAo-halogen  and  pnra-halogeii  benzoic  acida. 
Phosphorus  pentarhloride  does  not  react  readily  with  lUe  hydroxy- 
boiizoTc  acids;  hence  the  halogen  benzoic  acids  caiinot  be  satis- 
factonly  prepareii  by  its  aid. 

As  would  be  expected,  the  acidic  character  of  benzoic  acid  is 
strengthened  by  the  intriKluetion  of  halogen;  the  diesociation  con- 
stant/C  of  Uu-  halogen  beiizoie  at-ida  \&  greater  than  that  of  hejiz- 
oip  api<l  itself.  Fur  benzoic  acid,  K  is  O-Oofl,  for  o-ehlnnilienzoTc 
aeiil  0  132,  for  m-chlorobenzoie  acid  ()■f)l.^.'>.  fur  /M'hloroI>enzoTc 
acid  0-0()9.'l.  This  shows  that  the  chlorine  atiun  in  the  wrtAn-posi- 
tion  exercises  the  greatest  influence  and  that  in  the  ^JCim-pofution 
the  least,  wliile  for  t  he  m-eompound  K  is  iiitenuLHliate  in  value. 

Combinations  of  halogen  wit  h  l  he  .sulpho-group  are  referred  to  ia 


nZ.  STDROXn.  OBBITATITZS. 

ITitni&opbeuol. 

838.  This  compound  reacts  in  certain  respects  as  though  it  had 

NO 

the  e^institution  ^i^*<i)i{^  although  it*)  (onimtiou  from  quinone 

and  hydroxylamine  points  to  the  constitution  C^^„       .    It  is 

formed  by  the  action  of  nitrouB  acid  upon  phenol,  or  of  caustic 
>8sh  upon  nitrosodimethylaniline: 


mrROSOPHENOl  MND  KtTRCM'HF.NOLS. 


4J7 


¥ 


•^*    OH "     »    '^OH  ''■  "*°* 

0N<^^fN(CH.)7T"?|QH  =  H.\(CH,),  +  ON<^^OH. 

Like  other  oximes,  nitrosophenol,  or  quinone  oxime,  unites  with 
It  ifi  a  colourless  compound,  pr>'stflllizinR  in  nrodlcs  which 
won  turn  brown  on  exposure  lo  air.  On  oxidalioii  nnd  roductinn, 
St  behaves  as  t1iou|rh  it  were  nitrosophenot,  yielding  nitrophonol 
and  aniinophenolrespectively. 

Vitraphenola. 

83B.  Tho  increased  rcfttliiicss  with  which  the  hydrogpn  atoms  of 
the  nucleus  can  bp  substitutpd  after  a  hydroxyl-groiip  has  been 
introduced  intn  henzcnp  is  illustrated  liy  tin?  behaviniir  nf  the 
-  phenols  InwaniB  nilric  acid.  Wiiilr  it  in  ni-rcissiLry  to  i-nipliiy  mn- 
centrated  nilric  acid  in  order  to  obtain  nitrobenzene  from  bt^nzone, 
phenol  is  converted  by  dihite  nitric  aeid  at  low  teniperatnres  into 
wfAo-nilrupiienol  and  pnrfl-nilrophoiiol,  'lliese  two  iauniera  ean  be 
BSparated  by  distillation  nitli  steaili,  with  which  only  the  or(Ao- 
compound  is  volatile.  Mela-mi'i'ropArTiof  ean  be  prepared  from 
mrfH-iiitraniline  by  the  diazo-reactinn.  ^r/Ao-nitraniline  and  paror' 
nitraniline,  but  not  mcta-nitramlino,  yield  mlrophenols  directly  by 
fusion  with  potash : 

NH,  OH 

Qno.'  '""  0  +  """"^  ^  CTo.  '""  0  "  ™- 

NO,  NO, 

Tlua  shows  that  the  suhstitucnts  in  benzene  ore  mueh  more  readily 
replaced  when  there  are  .several  of  them  than  v^'hen  there  is 
only  one.  Thpaddie  charaeler  nf  phenol  is  strengthened  in  the 
nitrophenohi ;  they  ilrrnmpnsf!  all  rnrhnnatcs,  although  nitrophenol 
is  precipitated  fnmi  a  solution  of  an  alkali-nitrcipheiio.xide  by  carbon 
dioxide. 

340.  The  best-known  nilrophenol  derivative  is  picnc  add,  or 
l:2:4;6-trinitrophcnol, 


NO. 


NO,<i 


OH 


1/ 
NO. 


4a» 


ORGANIC  CHEMISTRY. 


This  substiLnec  has  long  bM-n  kiiown,  and  Is  produced  by  the  action 
of  concentrated  nitric  acid  upon  a  large  vaiiety  of  substances,  such 
as  silk,  leather,  remriH,  aniline,  indi^.  rtc.  It  is  prepared  by  dis- 
solving plicnol  in  concentrated  sulphuric  a«id,  and  carefully  adding 
small  quantities  of  this  solution  to  concontrated  nitric  acid  of  1*4 
sp.  gr.  An  energetic  reactidii  lakes  place,  after  which  the  reaction- 
nuxtUTV  18  wanned  for  Koria>  time  on  a  w&t«r-bath;  on  cooling, 
picric  acid  crj-slalliw-s  out.  It  cannot  be  further  nitrated  :  in 
other  words,  it  is  the  ftnal  pruduct  of  the  action  of  nitric  acid  on 
phenol.  Tliis  explains  itjt  resulting  from  the  action  of  nitric  acid 
upon  such  heterogeneous  8\ibstances. 

Soli^l  piprie  Beid  has  only  a  ven,-  falrl-yellow  eolour  when  pure, 
but  its  nqunous  solution  is  deep-yellow.  It  is  a  strong  acid,  and, 
therefore,  undergoes  considerable  ionization  when  ilissolv-ed  in 
water,  the  yellow  colour  being  characteristic  of  the  anion,  since  t.he 
solution  of  this  acid  in  petroleum-ether,  in  which  no  ionization 
occurs,  is  colourless.  It  ie  eillghtly  sohible  iu  cold  wat«r,  and  is  not 
volatile  with  steam.    It  molts  at  122°. 

A  coiiaideration  of  the  fnllowing  reactions  ahowa  that  picric  add 
Is  comparable  with  Ihi-  rarlioxylie  acids.  Phosphorus  penta- 
chloride  repUces  the  hydnixyl-group  by  chlorine,  with  formation 


of   picryl  chloride, '  ^j 


which  has  the  character  of  aa 


acid  chloride.  Thus,  it  is  decomposed  by  hot  water  into  hydro- 
chloric acid  and  picric  acid,  and  with  ammonia  yields  picramide 

^^^mv'^'l^'^-    t^iiver  picralc  and  methyl  iodide  yk-ld   the 

methyl  ether;  thia  has  the  properties  of  an  ester,  being  saponified 
by  boiling  with  concentrated  caustic  alkalis,  an<l  yielding  picrainide 
on  treatim-nt  with  ammonia.  Thcte  faets  afftird  further  evidence 
of  the  renmrkable  increase  in  tlie  reactivity  of  the  hydroxyl-group, 
due  io  the  preseui-e  uf  tho  three  nitro-groups. 

I*icric  acid  yiirUls  well-tlefmed  crystalline  sails,  of  a  yellow  or  red 
colour,  ivhich  arc  explosive.  The  potassium  salt  diasolvce  with 
difficulty  in  water,  and  the  ammonium  salt  explodes  by  percussion, 
although  the  acid  it.solf  doe.s  not. 

Picric  arid  yields  moleculaT  compounds  with  many  aramatie 
hydrocarbons;  for  example,  with  naphthalene  a  compound  uf  the 


MTROPHENOLS  AND  AMtNOPHENOLS. 


4*9 


formula  C,(,H,C,H,(NO,),OH.  These  rryataliizc  w-cU,  and  aitj 
winietime?  employed  with  advantage  in  the  »'paratUm  of  hyilro- 
carbtms.  or  in  their  idfntifitration  by  means  of  the  nicltiag-points 
of  thesp  fumpnumls.  Pk'ric  acid  is  readily  (.'UmtimlHl  from  tbem 
by  the  actiiin  tif  aiiimunia. 

I'imr-  arid  can  be  ttsttd  for  with  an  atjueoiis  solution  t>f  polas- 
sium  cyanide,  which  yields  a  red  colouration  due  )o  the  funnution 

I  of  isttpurpuric  acid. 

Picric  acid  Is  cmpKiycd  as  an  explosive,  usually  in  the  fnrm  of  its 
animoniuni  salt,  which  ienvos  nt>  residue  on  explosion,  and  is  a  eon- 

^Blitucnt  of  ■■  lyddite.**    It  Is  ako  used  as  a  dye,  imparting  a  jxllow 

,  colour  to  wool  and  silk. 

Slyphnic  acid,  C,H;v,,,'?,  is  a  Ivw  of  a  nitrated  dihytlroxy- 

bcnaone.  and  is  obtiuited  by  the  action  of  rxild  nitric  aeid  upoh 
rcsorciiiol,  as  well  as  from  wfrtaln  gum-rej«ns  by  the  same  meaiis. 
The  conversion  of  ni-nitrophenol  into  styphnic  acid  by  the  action 
of  nitric  acid  is  a  remarkable  reaction,  the  formation  of  a  liydroxyl- 
group  taking  place  simultaneouely  with  the  nitration. 


AmiDopheaalt, 

841.  Aininophciiols  are  foniial  by  the  reduction  of  nitrophenols. 
TIic  acidic  character  in  these  compounds  is  so  weakcnrd  that  tliey 
do  not  combine  with  bases;  on  the  other  hand,  tliry  yield  salts  with 
acids.  In  tile  freo  state  the  aminophcnolfi  arc  colourless  eoUds, 
crj-stallizing  in  leaflets,  and  readily  Himed  brown  by  atmospheric 
oxidalinn  uith  formation  of  a  resin.  Their  hydroelilorides  anj 
more  stable. 

a-Ami7iaphenol  yields  compounds  by  the  substitution  of  acid- 
rcaiducs  in  the  amido-proup;  tlicsc  at  once  split  off  water.  They 
toe  cb1Ic<1  ankydro-bascB : 


^|6"C-H, 


'0 


li 


AcMyl-drrlrikil*« 


:.CH,. 


8Ui»  Dj  lainliwp  aaaoU 
Aiitiydro  bAM 


On  treatment  with  acids,  amiaspheaol  and  acetic  acid  are  regen- 
erated.   , 


<Sb. 


--T    — 


•430 


ORGANIC  CHEMISTRY. 


^■Am-nojihenal  is  obtained  by  the  cl«etro-roduciion  of  iutrt>-^ 
benzene  in  acid  solution  (293) . 

Tlw  alkaliue  sotiitimi  of  p-mni nopheuot  rapidly  MqiottW  ft 
colour  uulese  sodium  sulphite  is  present.    This  solution  la  Mid 
the  namo  "  rbodinal,"  and  ia  used  as  a  pbotagraphic  developer. 

LuuiiRF.  U»8dJacoTered  c«rtfiiu  ^ueralcooditions  which  aroHMtia, 
corupoiiiids   must   fulfil  lo  ^«  iiTail.iWe  ag  phologntphic  developot 
Tliey  must  eithtr  contoifi  Mnw*  pydroxyl-gronps  or  AmJdo-jn^>aiH.  or 
at  least  one  of  eacli.    In  order  ttiat  the  deraloping  action  ma)-  not  b« 
interfered  with  \vlien  subsiituenis  are  pTesent  in  the amido  group  ad 
In  llie  hj(]roiyt-)[roiip,  luit  lew*  than  two  such  UDSubsiittited  gTOupa"* 
must  bo  present  in  the  molecule. 

A  dcriTailrG  of  p^minophenol  used  in  medicine  is  phenaixtin  oc 

atvti/lp/ienetlfUnf,    ^t^i<.Kif  ^  nrt'    **>*    ncutamino-d*rivatiT»   of 

pheiietole.  C,n,-OC,l!t. 

SullA  of  I:  Q:4-rliftminf>i>hi>nol  ar«  cmploj-«d  as  photographic  de- 
TclopvRs  uuder  t}i«  namo  "amidol." 

Monohy  droxy-acld*. 

343.  The    most     important    of     tiic     monohydroxy-acida    Is 

OH         1 

o-hyiiroxy benzoic    acid,    or    aalicylU    acid,    ^ii^^t'^cOQVf  2*     '* 

derives  its  name  from  salicin,  a  gliicosidc  in  the  bark  and  leaves  of 
the  willow  (jw/ii);  on  hydmlj-Ms,  this  substance  splits  up  into 
aaligfmin  andgluooRc: 

C„H„0,  +  H,0  =  C,H,0,  +  C,H„0^ 

Wllcia  SslleralD  Ulnuuva 

Saligcnin  U  the  almhol  rorroBpnnding  to  salicylic  acid,  into  vhieh 
it  is  converted  by  oxidation: 

Snllicoiiiu  Sallcy  Ik  acid 

Salicylic  acid  \s  present  as  methyl  ester  in  oil  of  winter-green 
(Guaithfrta  profunifcens) ,  from  which  the  acit.1  is  still  obtained  for 
plianiiaceutical  U)«e.  It  can  also  be  prepared  by  the  action  of 
nitrous  acid  on  anthraniHc  acid.o-aminolienzoTc  acid  (351),  by  fus- 
ing (^^hlorobenzoic  or  o-broniobenzoic  acid  with  caustic  potash,  and 
by  other  nictliods. 

Salicylic  acid  in  mantifactured  by  a  process  discovered  by  Kolbg, 
In  nhicb  sodium  phenoxide  is  licatcd  with  carbon  dioxide  in  an 


SMUCYuc  ^ao. 


autoeUrc  at  130°.  Sodium  phenyl  carbonate,  CaHj-O— COONa,  is 
formed  as  sui  iutcrmediate  product,  and  on  beating  is  converted 
into  sodium  salicylate: 

C,H»0\a  +  CO,  =  CJIe-O-COOPfa; 

^•**»*^t>.CO0Na  ~  ^'^^'^OEI 

When  COt  i«  passed  over  potaasinm  phenaxide  below  150',  sallcylld 
acid  ppsulls;  but  at  Ji  liiglit-r  tetnpemtare,  220*,  ^hydroxjfhvmQlc  aeid 
U  (oniied.  Sodium  plienozide,  on  tlie  olhor  band,  yields  only  salicylic 
acid  at  220* . 

Salicylic  acid  is  a  white,  crystalliiio  powder,  which  dissolves 
with  difficulty  in  cold  wnler,  niid  molts  at  159*.  When  carefully 
healed,  it  sublimpR,  but  nii  rapid  heating  sjjlila  up  into  phenol 
and  carbon  dioxide.  With  hromiiie-watcT  it  yiflds  a  prcoipital© 
of  tliL'  formula  C*ll,nr,'01tr.  It  gives  a  violet  eolimration  with 
ferric  chloride,  both  in  aqiirous  and  alcoholic  solution,  wiiert^as 
phenol  dissolved  in  alcohol  doca  not.  Wlien  hoiltil  with  calt'ium 
chloride  and  ammonia,  a  BoUition  of  salicylic  acid  precipitate*  basic 

calcium  salicylate,  CbH,<^      >  Ca;  this  affortls  a  means  of  aepa- 

ratitiK  salicylic  acid  from  it«  isomers,  which  do  not  give  tlua 
reaction. 

^ftlipylie  at'id  is  a  powerful  autiseptii',  iind  is  employed  a.«  a 
preservative  for  foods  and  such  beverages  aa  beer.  It  is  not,  how- 
ever, completely  innocuoua. 

When  Ihc  acid  is  lu'sled  to  220",  it  Insr«  carbon  ditixidc  and 
water,  with  formation  of  wiicylic  phenyl  csUt  : 


OH 


CO,  +  H^+C.H,<^So(,^ 


This  compound  is  employed  as  an  ontiaeptic  under  the  name 
"salol."  By  heating  to  300°,  its  sodium  derivative  is  converted 
into  the  sodium  salt  of  phenylsalicylic  acid: 

"-«"«"^C0OC,Hs       ^""'^^COONa- 

iTli«  otiAycirfile  of  salicylic  aaid  UliroTod  try  Ilia  eryoscopjc  d«t«r- 
mlnattoo  of  ita  aolecuUr  weight  to  haro  a  moloculo  of  the  fnrniuta 


49* 


ORGMNtC  CHEMISTRY. 


/(yi,<Q  >)  ;  it  1«  i>btiiiii«<l  by  tbo  action  ol  phosphorus  axy- 

•Mortde  opon  ibe  Add.  This  anliyclride  onrstallite)  with  trro  mole- 
•dM«f  chloroform,  which  dm  driven  off  on  WNrmiug.  Tkia  process 
sm  lonnriy  as«d  in  \hv  pn.'piini(iou  of  pure  clilororomi. 

S49.  Mcta-  wid  pftra-Ayrfrori/ftmajFc  aeiSt  j-ield  no  colouration 
vitK  kfTw  chloride.    Tlioir  biuiic  barium  saite  are  insoluble. 

FMin  ilio  fnotibnt  tlio  niniio«iibsilttition-prodn«U  of  beoMOc  an 
■ok  knovii  in  JHOinerio  forms,  iho  coDdiisioii  U  drawn  that  xXm  six 
kydro^i  ntoiiis  or  botiKOfio  nro  of  equal  value  tMS).  Tho  followiug  ia 
a  Bun  direct  proof  of  tliin  cttoality. 

Phitio)  in  converted  bj-  tb«  aotion  of  phospboraa  bromide  into 
IroMobeiiionn,  which  yicldA  bcnEoTo  acid  when  tmttcd  witb  carboo 
Anxiile  and  aodiiiiD  (108.  4j : 

C,n,-OH  —  C,n,  Br  -»  a,H,-COOH. 

If  the  iKttiitoii  of  tli«  hydroxyl -group  in  ph«nol  ia  denoted  bj-  a,  the 
pgailion  of  the  «arboxyl-group  in  the  beiuwie  ncid  obtaii>ed  frum  it 
Biuil  also  be  denoted  by  a. 

Tlicro  ore  three  isomeric  hydroxy  ben  sole  aciila,  all  of  fchicti  can  bo 
eonrerted  into,  or  ubl«itiod  from,  beiuutc  acid  ;  tbwe  luay  be  denoted 
by  •;(<,  ti:-;,  and  a:d,  a  baing  the  [loaition  of  (be  carboxyl-group. 
and  fr,  c.  and  d  of  tho  hydrosji-group.  By  cllminaiion  of  CO»,  nil  of 
tli«w  yield  phenol,  proving;  that  the  poaitionx  of  tho  hydrozyl-ffroups 
ar«  of  equal  Tnliic  Uoroover,  since  benxolo  ncid  is  oblaioed  rn>Ri 
pb«nol,  a  mnst  bo  equal  in  rnlue  lo  Iho  otb«r  three,  ao  that 
-0  =  6  s  a  =  d. 

It  Iiiu  slill  to  )>e  proved  ib»t  tho  two  remaining  positioiu  e  and  / 
are  equal  in  rnUio  to  tho  other  four.  Tbo  staning'polm  for  thin 
second  part  of  lUii  proof  is  bviizulc  acid,  the  poailion  of  vrhoao  e^r- 
boxfl-group  may  aKniii  bo  indicated  by  a.  On  brominatloit  it  yiclda 
a  bromobenzolc  ticid  (Mcfa),  which,  since  it  oan  bo  eonvortcd  into  a 
hydroxy  he  nxolc  ncid,  muai  have  ita  Br^atom  either  at  6,  c.  or  d.  IaI 
it  be  arbitrarily  aasunied  th.u  it  ia  niiualcd  ate.  On  nitration,  thl« 
bromobenzolo  acid  yields  two  im>nicric  hromonitrobeiuoto  acids,  whose 
iBomeriSDi  can  evidently  only  be  diit  to  a  dilTereuce  in  position  of  tbo 
nilro-group,  sinoo.  in  both,  tho  carboxyl  ia  at  a,  and  t)ic  Br  at  c. 

These  two  bronionitrobetizotc  aeida  can  be  so  rednood  that  the 
iiitro-i;roup  is  converted  into  an  amido-gruup,  and  the  bromioe 
atom  roplnoed  by  hydmgim  at  ih«  aame  time.  The  «anM  aminobM- 
zolo  acid  multa  from  LfK.')i.  This  'is  only  potalUe  vben  tbo  pasitioaa 
oeoDpied  by  Ihenitro-^ronpa  relative  to  a  are  identical.  The  amino* 
add  thus  obtained  is  antbraniltc  a<nd  (SSI),  which  ia  readily  ooowttol 


EQUALITY  OF  SIX  HYDROGEN  ATOMS  OF  BENtEUE.      433 

Into  lij-droiybensoie  acid  (salicylic  «cid).  It  followtt  that  the  ntiro- 
groiip  ill  one  of  ihe  iaomi'Ttc  bromoiiitrobciiEolc  MCida  is  ivt  h,  c,  or  d. 
As  it  was  arbitrarilj'  aaaumed  that  tho  Bralnm  is  at c,  then  (he  choice 
lici  between  h  and  il ;  niippoM)  it  to  be  h. 

Thti  nitPtvgToup  in  llie  other  brornonitrobejiKoTo  add  eannot  l>« 
aiCtuledHt  </.  since  llie  ainiiiobotiKurcHclil  obtaitivd  from  it  vruiiM  tlieu 
bo  d  :  <i,  and  thortiforc  difForcnt  from  the  amino-ncid  a  :  b,  just  as  the 
hydroxybeiizolc  acid  a  :  ti dirfcrs  from  a  .b  and  a  :c;  nhcrcaa  expcri> 
ment  provea  that  the  tiro  amino-acids  are  idoiitical.  The  nitro^group 
In  the  other  bromonilrobcnzoic  acid  miisl  therefore  be  at  e  or/;  let  It 
be  arbitrarily  supposed  to  bo  at/,  and  it  follows  that  b  =/, 


cn,-oooH- 


•Br        c, 

,  CH.^coon  a 

^  \nO,     6 

/Br        c 

^  c.n,f-coou« 

^MO,     / 


r  n  /coon  0 

^•'^VNa.6=/. 

Auiiinuiilic  Mli 


The  equiilily  of  lli«  [losition  e  with  th«  others  U  proved  simitarly 
Anthraiiilic  acid  (a  :  fr=/)  is  converted  into  hydroxybcnzoic  (sivlicyiic) 
acid,  which  on  nitnilioii  yields  two  JBomerio  nitrosniioylic  acids,  whoee 
hydroxy!  cim  be  ^xohaogud  for  liydroKtMi  by  a  pruccita  wlitoh  uc^  not 
be  dmtcrll)ed  here.  Itoth  ylnld  the  %an\t.  nil roh^riKoTc  acid,  from  winch 
follows  ibc  cqiiivaluncL-  rclntivu  to  a  of  Ibo  two  positions  occupicKl  by 
the  uitrO'groups  iu  the  iBomeni.  One  of  these  positioni  is  c.  since  on 
redactioo  this  nitrobcnsolc  acid  yields  fM-aiDioobenKolc  acid,  which 
cat]  be  converted  into  the  above-tnentlonnd  iicbromohertEoTc  add  a  :  c. 
Tie  nitro-gronp  in  Ihs  other  nilrosnllcylio  acid  cannot  be  in  th«  posi- 
tion 6  =  /,  Hs  the  niLmlKiiiujlc  B«i<]  obtained  fmm  it  dcjcs  not  yield 
anthmnilic  acid  on  reduction;  position  d  ii  also  oxclndcd,  since  it 
would  not  allow  the  Iwo  uiiro!*enzoio  acids  lo  he  identical.  There 
remains  therefore  only  the  poeilion  «,  from  wbieh  it  fotlowa  that 
c  =  e.    Hence,  a  =:t  =  c  =  d  =  e  =/: 


Aultiraiillic  adil 


COOH     « 
on        b=/ 


<i 


\no,        r         -^ 
/CO0!I    a         N 
C,H.^OIt      b=/ 

NnO,        e 

ISMueric  bilroMli«]'lic  ftOidl 


/COOH  a 

^'"'\N0.    c  =  t 
Kltrabeamtc  acU 


4iBtnol>oDsotG  Mid 


434 


ORGANIC  CHEMISTRY. 


Bfhydrozy-acids. 


y€OOH  1 


344,  Among  thcs^,  protocaUchuic  add,  CgE^Oll       3,   may 

NOH       4 

be  mentioned.  It  is  obtained  from  many  reana  by  fusion  with 
potash,  and  sj-ntheticoJIy  by  h<^ating  catechol  with  ammoniunijj 
carbonate,  the  Intttr  mcthiid  being  a  striking  cxampie  of  (ho  rwwli-' 
ness  with  which  the  carboxyl-groiip  can  eumetiniGS  be  inlrodueed 
into  the  ring.  It  Is  easily  soluble  in  n-ater;  it  reduces  an  ammoo-j 
iacal  xilvrr  solution  but  nut  an  alkaline  copper  one.  It  gives 
characterwtic  reaction  with  ferric  chloride,  yielding  a  KTcen  colour,] 
which  rliangcs  to  blue  and  finally  to  red,  on  ftddition  of  a  very 
dilute  BolutioQ  of  sodium  carbonate. 


It 


Trihydroxy-ftfiidf. 

,COOH  I 
/oh      ^ 

346.  The  best  known  of  these  is  gallic  add,  C,H,^  ,  j{J       J. 

OU       5 

is  ft  constituent  of  g^U-nuts,  tea,  and  dim-diri,  a  material  used  in 
tanning.  It  is  usually  prepared  by  boiling  tannin  with  dilute 
acids.  It  cryFtlatl  izi>»  in  fin<>  needier,  readily  soluble  in  hotwater.i 
It  was  mentioned  in  314  that  the  acid  loses  CO,  on  heating,  fcnrn-' 
ing  p>TogaiIol.  Gallic  acid  rrducra  the  italts  of  Kold  and  silver,  and 
gives  a  hluiBh-black  precipitate  with  ferric  chloride.  In  alkali 
Bolution  it  is  turned  brown  in  the  air  by  oxidation,  in  the  same  way 
as  pyrogallol, 

GnlllG  Hold  in  uKed  in  the  maDufacluro  of  b)u»-b]ack  iiik.  For  Ifala 
purpoM  iu  n(|U«ouB  aolulion  is  oiixod  with  a  aoluliou  of  ferrous  sa\-  • 
p]i%t«  conCalnltig  a  traceof  free  Kiilpliunc  acid.  Without  llio  acid,  i 
forroua  sulpliutc  nuuld  quickly  oxidize  iu  tho  air,  giving  a  tbiclc,  blnck 
jirvcipilntu  witli  the gnllic acid;  Ibts  oxidHtioD  isrelartled  iu  k  n-maik- 
able  mnuncr  by  the  addition  of  a  very  amaU  qiiantit)'  of  su}phiii 
acid.  Ax  sood  us  tliu  solution  is  broujiht  into  contact  with  paper,  tbe^ 
free  acid  is  neutralized  by  tho  alumina  always  preasnt  in  the  lattef, 
anil,  Its  oxidation  is  no  loiigor  pnivenicd,  llic  wriiing  In  drying  tarns 
deep-blaclc.  As  the  mixture  of  the  aolntions  of  ferroua  sulphate  and 
gallic  acid  hn_s  only  a  faint  browii  colour,  which  would  make  the  fr 
writing  nlmoRt  invisible,  indigo^nrmine  is  added  to  tbe  mixture,  Thi 
Imparts  lo  the  ink  coming  from  the  iwu  n  darV-bluo  colour,  whkb 
cbangos  by  the  abore-mentlonod  process  to  a  deep  black. 


Ty4NNlNS. 


43S 


The  tannins,  ot  tannic  ociclB.  an  verj' closely  related  to  gallics  acid, 
and  are  widely  distriliiited  in  tht  vegetaMp  kiiigdotn.  The  tannitis 
are  coiniiounds  which  htl-  wilubk-  in  wdtc-r,  have  a  bittt-r,  astringent 
taste,  yield  a  dark'bluc  or  green  prenipitate  with  fviric  Kalt«,  con- 
vert substances  cfniiaining  gelatine— such  as  animal  hides— into 
leather,  and  precipitate  albumiaB  from  their  solutions.  Some  of 
the  tannins  are  plucnades. 

The  most  typical  tanning-material  is  tanniv  or  tannie  anil,  con- 
tained in  oak-bark.     It  is  a  derivative  of  gallic  acid,  into  wliii-h  it  is 
vcrtejd  by  boiling  with  dilute  hydrochloric  acid.    Taonin  is 
optically  aetivc,  and  seems  to  have  a  somewhat  complicated  molee- 
ular  structure. 

It  is  best  obtained  from  gall-nuts — jiatholo^cal  excrescences  on 
the  leaves  and  branches  rif  tlie  oak,  raiiKed  liy  an  insect.  Turkish 
gall-nutit  are  esperially  rich  in  tannin,  ^nekliiig  &s  much  as  65  jkt 
i«cut. 

TAnnln  ImpurtaiUtchariLcterUtiQ  bEtt«rtAstc  to  many  t>OT«nLgct— to 
tua  nhii'Ii  lias  been  too  luniu;  hifuBtKl,  for  inKlaiice.  Tlie  iidditiou  of 
milk  romoTrs  this  hitlcf  Imio,  b««ause  the  IhiiDin  forms  na  in«olublo 
oumpouiitl  wilh  tbo  nlbumin  pnacnt  in  Ihc  milk. 

Tannin  is  a  white  (somctimea  yellowish),  amorphous  powder 
ily  soluble  in  ^vater,  only  slightly  in  alcohol,  and  insoluble  in 
her.    It  forms  salts  with  two  equivalents  of  the  metals,  ami  pre- 
icipitales  many  alkaloids,  such  as  strychnine  and  quinine,  from 
.heir  atiiieouB  solutions  (401). 

A  liistinction  is  drawn  between  the  difTerent  kiods  of  tatuiing- 

|sul>fi1ance8,  which  have  properties  analogous  to  those  of  tannin,  but 

iffcr  from  it  in  composition.     They  are  named  after  the  planta  in 

hich  they  are  found;  kino-tannin,  cateehu-iannin,  moringa-lannin, 

coffte-iannin,  oak-tatinin,  quinine-tannin,  and  others  are  known. 

S46l  The  taunins  aroiis«cl  in  fM-didaa Hni  In  tlia  tanmnt/ nf  hida. 

Id  miikiag  leather,  tbo  hidu  is  naturatiMl  vritli  tliti  tnaaiD,  bocaiisa 
wiUiout  this  treattoenC  It  cannot  b«  usi-il  in  lliv  mauufmotur«  of  shoes, 
etc.,  ftince  it  soou  dries  to  a  biiri].  honi-iiko  substance,  or  in  the  luoiai 
condiitou  becomes  rollun  When  saturated  wilh  tauniu  it  lemnins 
pliant,  aud  docs  aot  docomiKisc. 

The  skin  of  nu  animal  coDsisIs  of  thrtw  Utycrs.  the  epidermis,  tba 
cuticle,  «ud  the  fatty-layer.  The  cuticle  being  I  he  part  mttdc  im* 
leaOiiT.  the  two  oilier  layers  arc  removed  b;  susi^nding  (li«  hides  ia 
running  «at«r,  ahea  th«  epidermis  and  fatly  layer  iH^m  to  devom- 


43*  ORGANIC  CHEMISTRY. 

pose.  And  lire  ouUf  removed  by  meAns  of  a  blunt  knife.    AlteniAte 
horiEoatal  la>'9n  of  tbe  hides  thus  prt-pared  and  oak-bark  or  sonw 
other  matonal  coataining  lantiin  Are  plAced  in  l&ri:^  troughs  or  ¥«(<(, 
wbich  are  ihen  fllled  with  water.     At  the  end  of  six  or  eight  w< 
the  hi(l«a  arc  tnkeii  out  and  pl&ccd  in  a  aecond  Tat  cootjiinlog  freih* 
bark  of  utrougcr  qiuilily.    This  ii  contiuuecl  nllh  increaAin^lf  ooowa- 
trAled  tADDlD-solutiotu  tintil  tbo  bidM  aro  porfeetl;  tftQD«d,  tb«  proceat 
lasting  ta  long  as  two  nr  three  years,  Accordiog  to  the  thictnt^i  of  ihe'l 
hide.    Whelher  a  hide  is  tborougbly  utnrated  or  tAOticd   maf  be 
Judged  from  ih«  appi-anince  of  iis  cnM»«eclloii,  or  by  trentmcnl  wiih 
dilut«  Acetic  acid  ;  if  this  ttoatmetit  tDAkcs  ft  awt^ll  up  InlcriiAlly,  It 
shows  that  the  conirersion  into  Irathcr  is  incomplete.    It  is  still  a, 
natter  of  doubt  whether  lanniof;  is  a  tnecbanioAl  or  a  ehemrcal  proMMvl 
According  Co  some,  lh«  Uimln  U  .'*imi>ly  de]Mniied  mechanically  in  the 
t)id<M  ;  Recording  to  others,  ehctnicnl  union  takes  pUco  lielweom  the 
tissue  of  the  hide  and   the  tanaio.    The  first  view  it  hold  by  Dioot 
chemists. 


Acids  CoDtaiaing  Hydiroxyl  or  Carboxyl  In  the  Side-chaios. 
347.  Three  different  types  arc  here  posdWe: 

1.  OH  in  thesitU'-chaiii,  COOH  in  the  ring; 

2.  COOH  ill  the  sitlc-<hftm,  OH  in  the  ring; 

3.  OH  and  COOH  IwUi  in  the  fude-chaiii. 

The  following  are  repreaontatives  of  these  three  claaees. 

Oil  OH  I 

1.  Htjdroxymcihyllf^TJsoii-  acid.CtHt<.,Qka  «'  "**  mentioned 

in  826.    It    yields   phthalide    by  separation  of   frat^r,  and  u 

CH  CI 
obtained   by  UiiliiiK  v-X'jlylcnc  chloride,  C,H,<(-.u*™,  with  water 

and  lead  nitrate. 

OH 

2.  p-lIydroxyphmylpTvpionic  acid,   f'i*'4<(:u  .riL.mOH    ** 

of  some  inipf)rtance  owing  to  its  relation  to  tyrosine  (M.P.  235") — 
which  derives  its  nanie  from  its  presence  in  old  cheese,  and  is  pro- 
duced when  alljiniiiiis,  such  as.  thf>  white  of  ogg.  hom,  hair,  etc, 
are   boiled  witti  hydrochloric  or   sulphuric  aeid.      Ite   formula 

Al 
UC,H„NO„andils  slnicluro  HOC,H..CH,.C^OOH;  it  is 

a-unino'acid   correaponding    to  p-hydro.x>'phenylpropiooic   acid. 


HYDROXYCINNAMfC  AND  MASDEUC  ACIDS.  437 

fan  amino^vid.  tl  yields  salts  with  acids  as  well  as  with 

OH 
i>//3«lh»iyanmimK:an'rf,CflIl4<f^tj.pTT.pQj^tT,  exists  in    two 

forms,  cumaiic  add  and  cunuirinic  add,  which  art;  easily  converted 
into  cufh  titiitr.  Cumarinic  uciii  is  nnt  known  in  the  free  slate, 
but  only  in  the  fonn  of  aalt^,  siiw.K  it  iil  nnre  la^irH  a  inolnculc  of 
water  when  set  free,  yielding  cumarin,  the  arcmialic  principle  of 
wood-ruff  {Aipenda  odomla).  Cimiaric  acid,  on  the  other  hand, 
does  not  yield  a  corresponding  anhydride;  reniuvn!  of  water  pro- 
duct* cumarin.  wliith  is  converted  into  salt*  of  cuniarinin  acid  l>j 
treatment  with  alkalis.  This  behaviour  recalls  llial  of  fiiniaric 
and  inalei'c  acids  (170), and  it  may  be  assumed  that  this  is  a  similar 
east  of  stereoisomerism.  Both  acids  may  Uitn  be  represented  as 
follows; 


H-CC,H,-OH    H-C-C.H,-OH 

II  -H,0 

H-u-a   "" 


HOOC-C-H 


■COOH 


ti< 


CmnarUaciiI: 
«•  naoorrHHiNHidfPic 
•■ilifdrlilw 


Ciimnirliilc  acid: 

only  knirwii  111  llir  torin 


H-CC.H, 

II    >o. 
H-COO 

Cuinai'tu 


Cumarin  can  he  obtained  from 
oynihesis  (309):  acetylcumaric  acid,  C„II,< 


9alicylaldehyd«  by  Perkin's 
0|C,H,0 


is  first 


■CH:CH-COOIH' 
formed,  and  is  converted  into  cumarin  by  healing,  acetie  acid  being 
split  n(T, 

3.  Mandelic  acid  lias  both  hydroxyl  and  carboxyl  iii  the  side- 
chain.  Its  coastitulion  is  CflH,-CHOHCtXJlI,  as  its  synthesis 
frnm  heiualdeliyde  and  hydrocyanic  acid  indicates.  The  mandelic 
Acid  fiiuiid  in  nature  is  Ixvo-rotatory;  the  s>-nlhellcal  acid  can  be 
split  up  by  the  action  of  eulttires  obtained  from  mildew  (PeniaUium 
^aucum),  the  dextro-rotatory  acid  being  left  intact-  The  decom- 
pOEilion  is  also  effected  by  the  fnrmalion  of  the  einchonine  salts, 
when  the  salt  of  the  dextro-rotatory  acid  rrystalUies  out  first. 

Bydrozy-aldehydva. 

8U.  These  can  be  obtained  artificially  by  a  synthetical  method 
generally  applicable  to  the  preparation  of  aromatic  hydroxyalde- 
hydes.  It  cnitsitits  in  treating  the  phenols  in  ethereal  solution  ivitli 
anhydrous  hydrocyanic  acid  and  hydrochloric-add  gas,  it  being 


438 


ORGANIC  CHEMISTRY. 


BOinetimes  sn  advantage  to  add  a  small  quantity  of  zinc  chloride  as 
conilensing-agcnt.  This  mode  of  s^'nthcsis  was  discovered  by 
Gattkhmann,  whose  name  it  Ijears.  The  hydrochloride  of  an 
imide  is  formed  as  an  iatenncdiate  product,  and  can  sometiinea  boj 
isolated; 

C,H,OH  +  HCN  +  HQ  =  C,H,<^^^.j^.jj.jjj^ 

On  treatjucnt  with  warm  water,  the  imide-salt  is  converted  mto 
fibc  bydroxyaldehyde  and  ammonium  chloride: 

p-Hydroxybmtatdckydc  is  here  obtained  from  phenol. 

/OH     1 
Salicytaldrhyde,  CoHjN^p^Ilo.  occurs  in  volatile  oU  of  spiratL 

The  »-hydroxyaldehydc8  colour  the  skin  deep  yellow. 

To  this  class  of  substanccH  beInng3TOnt?/i7i,C«IIjr-0CU|3*     ** 

\OH     4 

metli\'l  ether  of  pjiocatechualdoh yde.    1 1  is  the  aromatic  principle  of 
vanilla,  and  is  prepared  on  tlio  large  scale  bv  oxidizing  igocugenol, 
.Oil 


•      C,H,^OCH,  lids  substance  is  obtained  by  boiling  fuj^eno/, 

K         \CH;CHCH,  I 

,  with  alcoholic  potash,  which  alters  the  posH 


/OH 

VHj  CH:CH, 

tioQ  of  the  double  linking  in  the  side-chain.     Eugenol  is  the  chief 
coijstiluetit  of  oil  of  cloves. 

For  conipoumis  containing  the  hydroxyl-tcrtnip  and  the  sulpho- 
group  or  the  hah^gens,  (■/.•(oppcctively  333  and  338. 

IT.  coHroimis  with  the  mTBo-osour  and  amido  oroqp. 

Nltranlllnei. 

349.  These  compounds  can  be  obtained  by  the  partial  redoe* 
lion  of  dinitro-compound3  by  means  of  ammonium  sulphide. 
Another  method  for  th«ir  production  consists  in  the  nitration  of 


NlTROBENiOIC  AND  AMfNOBEHZOlC  ACIDS. 


439 


anilioee,  though  if  nitric  ncid  in  allowtxi  to  act  directly  on  this  base 
the  resulting  [jrodunts  arp  inosUy  th(»s«t)f  nxidatioti.  If  nitration 
18  to  be  carried  out,  the  ainid(»-group  inust  lie  "  protected  "  against 
the  aotion  of  this  arid,  cither  by  first  converting  the  aniline  into 
acctanilidc,  or  by  causing  the  nitric  &t:'«\  to  react  in  preerncc  of  a 
large  quantity  of  sulphuric  acid.  When  the  acetyl-compound  \i 
employed,  p-n\(raniHn(r  is  the  chief  product,  o-n\tTan\linc  being 
formed  when  milphum  acid  is  used. 

In  these  substances  thi^re  in  a  weakening  of  the  basie  eliaiacter, 
m-ntfrantTtTur,  for  example,  yielding  salts  which  are  decomposed  by 
water. 


The  0-,  m-,  and  p-nitranl lines,  Cf\\t<  \ j^'  ^"^  yellow,  crystalline 

Their  melting-points  are 


I 

^Kcorri pounds,  readily  soluble  in  alcohol. 
Hiespeotively  71°,  114°,  and  147*. 


Kitroheazok  Acids. 


350.  The  mf(a-conipnund  is  the  principal  product  obtainetl  by 
nitrating  benzoic  acid ;  some  of  the  wiAo-acid  and  a  very  small  quan- 
tity of  the  parn-aeid  arc  formed  at  the  same  time.  The  orlho- 
Icompotind  !.•;  lje.st  obtained  by  the  oxidaiiou  of  ort/io-nitrutoluene, 
and  is  characterized  by  an  intensely  sweet  taste. 
The  introduction  of  the  uitro-group  raust-fi  a  large  increase  in  the 
Value  of  the  diaaociation  cunstant  K,  which  for  iH-nznic  acid  itself 
ie  0006,  for  o-nitrobcnzoie  acid  0-616,  for  the  m-acid  0-0345,  and 
for  the  p-flcid  0-0396.  'I"hc  melting-points  of  these  acids  are  respec- 
tively 148^  141^  and  241°. 


I 


Aminobe  azoic  Acids. 

3&1.  The  most  important  of  these  is  the  o-acid,  called  anlkranUic 
oeiti,  first  obtained  l>y  the  oxidation  of  indigo.  It  hft.s  quite  the 
charaetcr  of  an  uinino-ncid,  yielding  KaltK  with  both  arids  and  bases. 
It  possesses  a  sweet  taste,  and  slightly  anlLseptic  prnpertles.  It  is 
obtained  by  the  method  of  IIimjcikwf.rfk  and  va.n  I>irp  (244).  by 
treating  phthalimide  with  bromine  and  raufllic  potash;  the  potas- 
sum  salt  of  phthalaminic  aeid  is  fir^t  formed,  and  then  changes  into 
anthranilicacid: 


ORGANIC  CHEMtSTRY. 


C^<gg>NH 

MiltuJiinJdB 


-*  ^•"i<  COOK         •^  ^ ''' wi 

PaUiHluRi  fiJktbmluitlukte 


t\X)H* 


jAnthranilie  acid  melU  at  146*,  and  can  be  sublimGd  witliout 
composition;  it  is  readily  soluble  iii  water  ajid  in  alcohol.  By  the 
Ithod  given  above  It  is  prepared  technically  for  the  synthesis  of 
fSgo,  bteachiug-powder  being  substituted  for  the  caustic  potash 
it  bro[uino< 


0RI25TAn01I  OF  AAOUATIG   COUFOTnTOS. 


303.  Orientation  is  the  dctcnni nation  ot  thn  positions  wKich 
the  side-chains  iir  stilwtitufiita  in  tlic  bcnzcnc^ring  occupy  in- 
relation  to  one  another.  A  dcsi'riptiori  of  a  number  of  the  most 
important  eubstitutod  bcuzcne  derivatives  having  been  given  in 
the  foreg()iti(;  paries,  it  bcconit>s  necessary  to  funiiah  an  insight  into 
tliG  mL'thiidg  hj'  whieh  orientation  is  carried  out. 

These  rest  on  two  tniiin  principles. 

1.  Heiative  lirlmiti'italitm  aj  pasUian. — Thv  compound,  the  posi- 
tion of  whose  siiiKitituentt)  is  unknown,  is  converteil  into  another 
with  known  positions;  from  this  it  is  inferred  that  the  first  com- 
pound has  its  siibstiluenLs  tirraiiK'H)  .•^iniitarly  tu  the  si-eond.  If, 
for  e.vaniple,  Uie  eonslitulion  of  one  of  the  three  xylenes  is  rectuired, 
the  hydroearboQ  can  be  oxidized;  the  particular  phlhalie  acid 
formed  indicoU"s  the  positions  of  the  methyl-groups  i»  the  xylene 
uud(;r  exaininulion,  |>rovided  the  positions  of  the  carboxyl-groujis  in 
the  three  phthalic  acids  are  known. 

In  order  to  apply  thw  methnd,  it  is  ncceswar)'  to  know  the  posi- 
tion.'t  of  the  .lulistituenlH  in  a  atiuil)  nunil>er  of  rompounds,  and  it 
is  further  a-tsiinied  that  the  ptmitionK  of  the  Kubstituent!)  remain 
the  same  cluriiig  Xhv  nnirsc  of  the  rractioii.'*  which  have  to  be 
mafle  use  of.  ICxprriencc  has  shown  tliat  this  is  true  in  most 
caBce,  although  the  poation  of  the  uide^hain  dcK's  alter  in  a  few 
reactions. 

It  WAS  «(at«d  In  S8SI  thftt  the  throo  bnnuMiulpIianle  aeljt  an  ,$oa- 

Tcrtet)  into  Rsorcinul  by  fusiuH  nilli  cuiietio  [xitiub,  Thers  SM  tfStsr 
exanplea  of  cliiingc  of  position  wbrii  llic  «iil(ilio-group  is  replftccd  hj 
the  hydroijl  group,  hj  fu&ton  with  caualic  nlkslis. 

In  order  to  avoid  erroneous  conchiwons,  it  is.  therefore,  desirable 
in  casts  of  doubt  to  check  the  determination  of  position  by  convert- 
ing the  substance  into  another  coinpcnind. 

2.  Abatiute  deirrmination  o}  pustlion. — Thia  is  the  detennina- 
tioo  of  the  pa>utions  of  the  subKlltueuts  without  having  recourse 
to    other    compuimds  tlic  positions  of  whose  subatituents  arc 


ORGANIC  CHEMISTRY. 


knows.  A  general  method  is  afTtyrdcHl  by  Kornes's  principle,  by 
which  it  ie  possible  to  ascertain  whelher  subslances  C^H^X,,  con- 
(aiuuig  two  8ub«titii(.'iit8,are  ortho-,  meta-,  ur  par(iH:uii)iKiuiulK;  this 
is  Kffei-twl  by  ik-tennining  the  number  of  trisubstilution-productg 
c«.>rTv»poiuliiig  to  them. 

Whrd  a  tliinl  gniup,  Y,  ifl  introdufied  into  an  ortho-compound, 
r,H,\,.  whether  Y  is  the  same  tis  or  different  from  X,  only  (wo 
tt>oiiK>ni  CM)  be  formed, 

X  X 

and 


the  IntmdiicUoii  o(  a  tlurd  group  into  a  mWu-compound  renders 
(hoaibli'  llir  furnmtioii  of  ^wee  isomers, 

XX  X 


JX'       "^       T 


(>• 


in  the  case  of  n  para-cninpoiind  the  introduction  of  a  third 
Ipyiclda  only  otic  triaub»tituti«n-|irx"lijct, 

X 

1Y 


In  addition  to  this  getieral  niethnd,  there  are  others  for  special 
own),  several  of  which  nmy  be  mentioned  here;  it  will  be  obecn-cd 
ijiat  they  fully  subiitantiate  the  conclusions  already  arrived  at  by 
K0llNCR*6  nielhod. 

1.  AbMlute  determiaation  of  poBitioo  for  or/Ao-coiopounda. 

353.  For  the  orthoser'wB,  the  strocture  of  a  dibromobensene 

inielting  at  -  P  is  tletemiined  by  means  of  Kobkeh's  principle;  this 

'body  yields  two  isomeric  nitrodibromobeuzenee.      The  constitu- 

Uon  of  a  xylene  boiling  at  143**  and  melting  at  —26",  has  also 

been  established  by  this  method;  it  gives  nx  to  tn-o  isomeric 


OIUENTATION  OF  AROMATIC  COMPOUNDS, 


443 


nltroxylenes  when  treated  with  nitric  acid.  This  xylene  is  con- 
verted into  pbthalic  acid  by  oxidation,  showing  ttiat  the  latter  is 
an  ortAo-compound. 

That  the  carboxyl-groups  of  this  acid  are  in  the  ortAo-position 
was  also  determined  by  a  different  method,  by  means  of  the 
oxidation  of  naphthalene,  C,jHg,  a  hydrocarbon  which  is  con- 
verted into  phthalic  acid  by  this  treatment.  This  fact  showa 
that  its  structure  must  be  CoH^  <  C<H^,  in  which  the  group  C^H^  is 
linked  to  two  positions  in  the  benzene-ring.  When  naphthalene  is 
treated  with  nitric  acid,  nitronaphthalene  is  formed,  and  is  con- 
verted by  oxidation  into  nitrophthalie  acid.  The  group  C^H^  has, 
therefore,  been  converted  into  two  carboxyl-groupp  in  this  case  also; 

NO.-C,H,<C.H<-*  NO,-C,H,<gggg. 


HltronaphtbAiene 


NlCrophthallc  acid 


If,  however,  the  nitro-group  is  reduced,  and  the  aminonaphthalene 
thus  obtained  oxidized,  phthalic  acid  is  formed.  Hence,  it  follows 
that  the  group  CjH^  forms  a  second  benzene-ring  with  the  two  car- 
bon atoms  of  the  benzene-ring,  so  that  naphthalene  must  be  repre- 
sented thus: 


The  oxidatjon  of  nitronaphthalene  and  aminonaphthalene  is 
expressed  as  follows ; 

/\C00H 


COOH 


XO, 


and 


HOOC/^ 
HOOcl^ 


ORGANIC  CHEMISTRY. 


This  shows  that  phthalic  acid  murt  be  an  orMo-compound,  because 
if  it  be  BESurD«d  to  have  the  mna-structurp,  for  example,  tiaphttia- 


lene  must  be  ro)>n«eiit«l  by  the  formula 


.  which  leads 


at  once  to  a  contradiction,  sinre  there  cnuld  not  thpn  he  a  benzene 
derivative  prodiired  by  the  oxidation  of  both  uitruiiaphtliak-De  and  I 
aiui  noriBphlhalenc. 

2.  Abiolate  dct«nDiDation  of  potitios  for  m/-(<i-ooinponodB. 

354.  The  proof  that  mesitylcne  is  s>'mnictrical  trimethylbonzenc 
(1:3:5)  isstated  by  I^dknburo  as  follows. 

H 

If  this  compound  has  the  eoostitution     )||      Ju  *<  ^^  thre« 

CH, 

hydrogen  atoms  dirpctly  linked  to  the  benzene-ring  must  be  of 
equal  value.  If  this  can  Im*  proved,  the  stnictun-  of  mesitylene  b 
established. 

The  proof  of  the  equality  ia  na  foUowa.  On  nitratiag  mesiljlene  a 
dlBltKMXXnpoiincI  is  obtaioetL     If  the  hydrocarbon  ia  represeowd  to; 

I.     C,(CH»>,HHU, 
the  dinitro-compAuud  ma;  be  arbitrarilj  nssumed  to  be 

One  of  thenitro-KTOu}»sof  ihedioiiro-«oinpoand  in  nKluecd.andih* 
reaultiiis  fimfno-orepound  ia  oonrfrricd  ioio  an  acvlyl  derivative  i 
luppocu!  that  Ihu  acnt)'t><Ieriv8Uve  ia 

III.     (.VC'U,),NO,NU(C,H,0)H. 

This  )ut»tanc«  can  bo  A|caln  ottnit<td.  wrjien  then  must  result 

c;(Ci!,i,Nb,!rmc,n,oiNb,. 

It  is  possible  to  eliminale  the  acHylamido-gronp.  NU(C1T,0).  froa 
tblit  uvmpounit  by  sapoiiiflrntion,  Riibi«qu«nt  diazotisatioo,  et&  la 
this  irajr  a  dinitromoaltjli^ne  wiih  ibo  formula 


ORiENT^TtON  OF  AROMATIC  COMPOUNDS. 


445 


ined,  And  U  tound  to  be  id«nticttl  with  ch«  former  dtnitro-pro- 
duct,th«  nitro-groups  q(  wbic'ii  Araataandfr.    Frotnthiiitfolloiri  ihnt 

a"  =  H'. 
NitroEDflsidl ne,  a  :h.  whose  Roelyl^compound  Is  rspreMntfrd  by  for- 
malA  III,  furnishes  a  further  proof  chat  II'  =  II'. 

When  tliD  ainidosiroup  \»  etimitiated  from  this  by  meaas  of  the 
dia2a-r«ne(ion,  there  is  formed 

tV.     CVCn,),NO,HH. 
Tliis  is  reduced  and  convened  inUi  an  iic«tyUcoRi pound,  ocotj']- 
meftidine. 

C!,(cn.),wii<c,n,o)HH. 

This  compMHid  can  bo  again  nilrati-d,  yielding 

0,(Cfl,SNn(C,TI,0>NO,U, 
it)  whioh  it  is  of  no  coiiaeqiiAiice  whmhvr  liiv  nitro-gronp  is  ia  ths 
poBition  h  or  c,  sinco  (lie  equality  of  these  poaitioiia  I'olatira  to  a  has 
been  already  proved. 

Oil  vliiuiiiatinK  the  acelylrunido-KToup  from  tbe  sukstanci!  lut  ob- 
.  talne<].  -t  Rjotionltmmeiiirylvnr  ts  produced. Identical  willi  t ho  cumpound 
IV;   it   Tollows   that   «=&=(■,   which  cooipktce  tho  proof  of  the 
Mjiiality  of  the  threw  hydrogen  aiunis. 
From  the  known  «tn.siitution  of  mesitylene  it  is  possible  lo 
deduce  the  stnidvirr  of  niany  ottier  compounds.     For  exariiple, 

/COOH 
jwrtial  oxidation  converts  it  into  mtsitylenic  acid,  C,H,;--CH,     , 

which  is  in  turn  converted  into  xylene  by  distillation  witli  limi;; 
this  compound  mnst  be  iwcfa-xylene.  Oxidation  converts  this 
m-xyleiie  into  isophthalic  iicid,  shnwing  that  the  cartx)xyl-group3 
in  the  latter  occupy  Uic  Tm'^a-pusition,  These  determinations  of 
positiun  tiavc!  been  fully  substantiated  by  the  application  of 
KCiLNKii's.  principle.  Thus.  NijLTlNo  lias  prepaatl  three  isomeric 
nitnixylenw.  in  which  the  relative  positions  of  the  iiicthyl-groupa 
are  the  same  as  in  the  xylene  obtained  from  mceJtyleuic  acid. 

Among  other  mrfa-eoinpounds  in  which  the  position  of  the 
j;roupi>  has  been  independently  cstahlished,  there  may  be  men- 
tioned a  dibromolienzene  boiling  at  2211*.  K6hnkk  proved  that 
corrpsiHindinjit  to  thi--!  substaiire  are  three  isomeric  tribromobenz- 
enes  and  thn-c  nilrfHlibntjiLiiben;:enes.  In  ronclusion,  it  may  he 
mentioned  that  tho  phenylenediamine  which  melta  at  62*"  can  be 
obtained  from  three  different  diiiminobcnzolc  acids  by  eliminalion 
of  CO„  80  that  it  also  must  be  a  fnrfa-comDound. 


44« 


ORGMHIC  aiEMISTRY. 


3.   Absolattt  determination  of  poiition  for  para-c«mpound». 

355.  KOrner's  principie  has  bwn  of  gn?Bt  sorx'ice  in  determining 
the  const  i  tut  inn  of  some  members  nf  ih*-  ;xim-scries.  For  example- 
from  the  sylene  boiling  at  13S°.  an<i  melting  at  1.1*.  it  was  only 
possible  to  obtain  one  mtroxylene;  the-  phenylenetliaminc  meltinK 
at  l-K)"  can  only  be  obtaioed  from  oii«  diaminobctuolo  acid  by 
splitting  off  CO,;  ete. 

These  del4>rniiriAtion5  of  jMiaitJim  have  hern  cunSmuKl  in  an- 
other way.  Thiis,  a  hydn>xybeiizoTe  acnd  melting  at  2l(I*  ha»i 
Iicoti  proved  to  have  the  jwra-croiistilntinii.  It  is  obtaint^l  from  n 
bnMnobnizoi i:  acid,  which  can  !«■  got  fnim  nnJiiiary  bromotoliimr. 
the  latter  IwiiiK  convert  il»h;  into  a  xylene  from  which  tcrephthiilic 
acid  can  be  ohialned  by  oxidation.  ;>- Hydroxy  benzoic  acid  affords, 
therefore,  a  valuable  basis  for  orientation. 

The  proof  can  bo  Klalinl  as  follows.  The  start inp-point  is  bromo- 
benxoic  acid,  obtained  dirr-rtly  by  the  Imimiiiation  of  benzoiV  aeid. 
Oil  nitration,  two  ianmeric  tiitrobromobenwi'c  acids  arc  fonoed, 
either  of  which  yield*  on  reducticm  the  same  aniinobenzoic  acid 
antbranilic  acid;  this  can  be  converted  iittii  Nklicylic  aeid  by  itieai 
of  the  diaxo-reaction.  It  follows  that  in  lH>th  the  isomers  Ihf  niiro- 
gnnip  must  bo  Hituatrd  syniniPlrieHlly  to  the  rarboxyl-group:  nt 
2  or  fl,  or  at  .1  or  ft,  if  thf  earboxyl-p otip  is  at  1 .  The  same  reason- 
injK  (•stablisht'S  tin-  posittmi  of  the  hyilnixyl-ftnmp  in  salicytir  acid. 
CuncrmiiiK  the  pcwiliun  of  the  bronune  atom,  it  ik  evident  that  it 
cannot  be  at  4,  Wcautir  tw<>  iwinicric  tiilrtK'om|M)undi)  whieh  woiiid 
yield  the  samo  aininobcDzoio  acid,  ou  nxluction,  could  ant  be 

;«bt*ined  from  Br/^      yCOOH,    The  bromine  atom,  must,  thrny 

iore,  occupy  the  w/u-potatioti  or  "fMo-iw'sition  to  the  cnrboxyl- 
group.  A  hydroxybeiuoic  acid  tucUinK  at  2U0*,  obtained  by  tliiis 
meaiLt,- must  thpjpfore  be  meta  nrortho.  Since  Uie  Isomeric  mlieylic 
.aeid  ean  al.so  be  only  »  mf/o-rniiipoiind  or  an  or(/t»-rompound, 
there  remains  nn  possibility,  except  the  para -structure,  for  the  third 
Jiydroxylwaizoic  acid  rnel I ing  at  210*. 

Detennin&tioa  of  position  for  the  Trisubatituted  and  higber- 
tabstitnted  derivatives. 

aS6.  This  can  u-sually  bo  efTi-ited  by  a»M?ertainirig  the  relation  in 
which  they  stand  to  the  diderivatives  of  known  coufctitutioa.    Fur 


ORIEHTATtON  OF  AROMATIC  COMPOUNDS- 


example,  since  a   certain   chloronitroaniline,  CBlI,a(NO|)(NH,>, 

U  obtained  by  nitratiog  m-chloroaiiilme,  <^      yCl,    and    jrields 

■^p^hloronitrobcnzene,    NO,Q^      ^Cl,  by  exehauge  of  the  amide- 

group  for    bydrogen,  it  follows  that    it  bos    the  constitutioo 
NH, 

NO,<f~)>Gt. 

A  more  oonipticaled  ciample  of  orientation  U  afforded  bj  the  way 
In  which  the  posilions  of  thn  groups  In  pterie  acid  an>  asoenained. 
Careful  oiiraiion  coavertd  [ibcuul  into  tiro  nioaonttropbeaolai 


OH 


0" 


and 


M.P. «' 


M.P.  114' 


Om  of  tlicw  must  be  the  ortAo-compound  and  the  other  tbo 
para-iiompounA,  txicxiise  iha  ibird  nicroplienol  caa  be  obtainiK]  twia 
w-dinilrobcnwjiw— the  oi>n«titutlon  of  vhich  \iM  been  proTwl  by 
il8  reduction  to  rii-phcuylt^nvdiutuinc  i8M)— by  reduclion  to  mcUt- 
nitraniline,  and  subsequent  Mchntigi*  of  Nil,  for  OH  by  dluolizing. 

When  further  nitratcil,  both  DitraplicDob  yield  the  same  dioitro- 
phenol,  which  can  tberetoro  only  havo  tha  formula 


\VO, 


ThenioiioDLtrophet]o1.whlchni«luat  114*,  iseonrorted  byoKidatioa 
into  qniiione,  and  must.  (her«fom,  be  tho  ;wra-ooRipni)nd,  For  tha 
body  melting  at  4A*  thcro  n^miuns  onlj'  iho  orilto-ttr\icl\m.  On 
nilrntioti  tliia  o-nJtrophcnol  yieldt,  in  addition  to  the  1  :3  :4-()ini- 
Iraplictiol  (OU  at  1),  another  dtnitropbcnol  wtlh  Ita  groupa  at  1 : 2  :  6, 
OH 

i    ,y      jNOij  f^p  p,j  conversion  of  this  ieto  iu  melhyl  ether,  and  heat- 


448 


ORGANIC  CHEMISTRY. 


ing  the  bitter  with  &looholl«  unmonift,  the  {^up  OCHi  is  repUc«(l  bj 

NH,;»ndthteiab»lAno«,  which lia»  the fonnuU'^O*!        1^^*,  U  »a- 

Tert«<l  bj'  tho  sabstitutioD  of  bydrogen  for  the  NEIi-groap  into  ibo 
ordinal*)-,  or  meta-,  dinitrobsnzeae.  Tliiu.  ve  h&ye  two  diaitropbeBois 
of  kuowQ  Btrueture, 

OH  OH 

NO./\lTO, 
and  I    J      • 

10, 

Further  nitrittion  conrens  both  of  thQS«>  into  picric  add,  vhidi  mtuC, 
tlienforo,  hare  tho  cooatitution 

OH 


lifo. 


wo. 


From  the  known  conitltnllon  of  picric  acid  maf  bo  iaferred  the 
posiliun  uf  Ihu  groups  in  ordinary  Irinitrobonzcno,  since  Itiia  com- 
poiiiKl  ia  Tf^julily  oiidiKil  to  picric  noid  (3111.  This  lrinitrob(>Tizeii« 
must,  accordingly,  hare  th«  aymniotricjil  »lructure. 

lafluenoa  of  the  snbstituenta  oa  each  other. 
367.  This  influpnce  is  vpr}'  irnportJint,  and  manifests  ttself  in 
varioiiB  ways.  It  airpcls  the  ptiisiiion  which  the  Biibtititumts 
take  up  in  relation  to  om*  another,  when  introrluced  Rimiiitancotisly 
or  in  succetwion  into  thc^  IvnzrnoniicleuN.  \.cX  us  ctmsukT  6rst 
the  fiiniplrst  ra.sc,  thp  introilticticin  of  a  srcond  atom  or  grmip  into  a 
mono5iil>slitiitr(l  conipnuii<I  CHgX.  It  js  fmind  that  one  of  the 
three  possible  isomers  is  always  obtained  as  the  chief  product,  the 
second  isomer  being  prodiicpd  in  less  quantity,  while  the  yield  of  the 
tlurd  isnjiiiiT  is  very  uiiall.  For  example,  when  beiiwjie  acid  is 
nitrated  at  0'*,  SO-2  p«-ceut.  of  mela-,  18-5  p*>r  cent,  of  ortho-,  and 
only  1-3  per  ci?nt.  of  pam-nilrobenitoic  acid  an?  formed.  On  nitra- 
tion at30°,mlrobL'D«unf  yii-lds  90-9  p<'r  reui.  of  the  mtia-fS-l  per 
cent,  of  the  orlho-,  and  1  per  cent,  of  th(^  para-compaaad.  It  has 
often  been  stated  that  the  introduction  of  a  second  group  resulis  in 
the  formation  of  only  one  or  two  isomers;  but  wbea  a  eticfol 
examination  lias  been  made  w  to  the  presence  of  the  third  isonwr, 
it  has  been  shown  to  be  present  in  minute  quantity;  so  that  it  is 


45« 


ORGANIC  CHEMISTRY. 


OrtAo-groupflsomclimwexcrt  a  remarkable  influence  in  rEiarding 
or  iMUtially  prevuiiling  reaclioris  which  otherwise  take  place  readily. 
Amongnthera  which  have  been  observed,  thefulhiwingare  examp!«i. 

It  is  known  thai  when  un  a('i<l  \»  disKolvcil  in  cxcetiS  of  alx<(>luto 
alcohol  it  can  br  alniont  c|uaiitibativcty  cnnvrrtixl  into  an 
ester  by  parsing  through  it  a  current  of  hydrochloric-acid  pas  (99j. 
Victor  Mbysr  and  his  pupils  found,  however,  that  eeterifica- 
tion  of  acids  containuig  two  groups  in  the  ortAo-positJon  relative 
COOH 

to  carboxyl,  Xf     ^X,  was  by  no  raeana  complete  when  carried  out 


in  this  manoer.  On  the  other  hand,  when  the  acid  has  been  con- 
verted into  an  cater  (by  means  of  the  alver  salt  and  an  alkyl  halido) 
the  ester  so  formed  can  only  bo  saponifioil  with  great  dHRctilty. 
When  th«  two  substitiientii  occupy  any  of  the  other  potiitians, 
those  peculiarities  do  not  manifest  themselves,  or  at  least  not 
^  to  the  samrextent.  Ketnnes  substituted  tn  the  two  ortAo-poa- 
CH. 

Mam,  <C      "^CO'll,  where  H   is  lui  Hlkyl-radicle,  cannot  be  can- 

into  oximes,  wherein  thev  differ  from  all  other  ketones 
CH, 

(Ka-Uiniethylatiiline,<f     ^NH„isnot  converted  by  treatment  with 

CH, 
an  alkyl  iodide  into  a  quaternary  base;  pen tamothylbenjconi trite, 
C^CH,),CN,  cannot  be  saponified  to  the  corresponding  acid;  the 

/NO,  2 
melliyl-hvdmgBn  in  o-o-dinitnitolueiie,    Cfln,^CM,  1,  rannot   be 

\N0,  6 
rcplaretl  by  halogens  even  at  a  high  teniperatutie  (200*) ;  this  is  also 
true  of  l:2:4-dinitrotohiene;  Auwt;rw  and  Jamieson  Walkkr  were 
unable,  in  spite  of  Qumcrous  attempts,  to  effect  the  hydrolysis  of 

OH 

o-uitroiaUc>'Uc    nitrile,     f  ^CN  ,    to    Oic    corresponding     acW, 
OH 


INFLUENCE  OF  THE  SUBSTITUENTS  ON  EACH  OTHER.     45' 

Groups  occupying  positions  further  removed  sometimes  exert 
a  similar  effect.  One  of  the  NOj-groups  of  symmetrical  trinitro- 
benzene  is  easily  replaced  by  OCH,  through  the  action  of  sodium 

NO, 
methoxide,   but    for    trinitrotoluene,    NOj<^      yCH,,  this  is  not 

NO, 
found  possible:  the  methyl-group  prevents  exchange  of  the  nitro- 
group  even  in  the  para^position. 


TERPEI7ES    AND    CAMFAOBS. 


358.  Atl  the  toqipups  h»vo  the  cmpiripal  composition  C,H„,  but 
most  of  lliosf  which  have  i)eeii  exflmined  have  the  moloeiilar  for- 
mula CjftH,«.  The  true  terpeiics.  C,oH,,,  will  Lhercfore  lie  (iescribed 
here,  ami  the  Hemi-tirpcnes.  C»H,.  as  well  aa  the  poly-ttrpena, 
(C»HJx,  left  almost  oulof  iiccouni. 

Most  camphors  have  the  fornmlft  C|oH,,0,  but  Boroc  varieties 
of  the  formulip  r,„II„OainlC,„IIj^<>ftre  known. 

Both  the  terpeiips  ami  camphors,  which  are  nearly  relate*!  to 
one  another,  arn  widnly  rlistrihutrd  throughnijt  the  vegelablo 
kingdom;  the  spccirs  of  Pimis  arc  particularly  rich  in  terpenes, 
and  yk'hi  oil  of  turtjontine,  a  mixture  of  thcst-  hydnwurbona,  n-hcn 
iliittillud  with  steam.  Common  or  Japan  camjjfior.  C,pH,/),  is 
obtained  in  the  same  way  from  the  camphor  tree  {Ijturus  cam- 
fhora)  and  Hnmeo  camphnr  or  iKirneol,  r,oH,,0,  fpom  Dryohalanopi 
aimphora.  Many  ethereal  oils  roiisLst  chiefly  of  compounds  C,,H„ 
and  C,J!„0. 

The  tcrpenf^  nrc  fhjpfly  lif]nid>i — verj'  few  are  soUds— which  boil 
at  temperatures  ranpinj;  from  loH"  to  190°.  They  have  a  charac- 
teristic 0<lour,  are  tolerably  stable  towards  alkalis,  but  are  eaailj' 
decomposed  on  treatment  with  acids,  or  on  being  heated  to  a  high 
teniperamre.     Somt*  of  lliom  are  oplti-ally  atlive. 

The  camphors  are  solid,  erystalliae  gulwlaiicca,  and  are  very- 
volatile  even  at  ordinary  tem|K?rature8.  Tliey  can  be  sublimed. 
and  arc  cliarat'ttTiiied  by  u  peculiar  odour.  I^)nie  varieties  are 
optically  active.  The  convertibility  by  various  means  of  the  tcr- 
penc9  and  the  camphors  into  arnmatic  bodies  betrays  their  relation 
to  the  latter.  Thus,  p-t^luic  n^cid  and  lerepluhalic  aoid,  alonp  with 
other  compoundn,  are  rjbtained  im  oxidizing  terpenes  with  nitric 
acid.  In  particular  they  an*  related  to  njmcne;  this  aromatic  hydro- 
caiboa  caii  be  obtaiQcd  from  the  tcq^ciics  by  the  action  of  Iodine, 

4Sa 


TBftPENES. 


453 


for  example,  and  from  camphor  by  moans  of  dchydraling-sgcaLs, 
BUch  as  phosphorus  pentoxido : 


C.,H..  4  I,  =  ('..H,,  +  2H1;  C.,H,^J  -  H,0 

T^rpttfn  CyttitiUa  Oiiii|)Uor 

Terpsnea. 


SS^.  The  natural  ethereal  oils  C,o]I,b  have  difrerent  physical  and 
chemical  properties,  acronling  to  the  particular  plant  from  which 
thej-  have  been  obtained.  In  default  of  iiielliods  by  wliich  Uw 
isomers  cntild  be  sharply  ilistinguishcd  from  one  another,  it  was 
fomierly  supposed  that  there  was  a  ^teat  number  of  cuiii|>uuiidh 
with  the  formula  C'loH,,.  ^V-^u.^cn  succeeded  in  preparing  well- 
dcfinod  crvKtalhne  derivatives  of  iJie  compotrnda  C',oH,„  and  thus 
in  dL>:ting:iiUhin^  the  esisting  woniors.  It  was  found  by  this  means 
that  the  niitiiral  etheri>al  oils  are  prineipally  mixtures  of  such 
isomers,  of  which  fifteen  liave  been  identified.  They  Br«  claaaified 
into  two  main  gronpfi. 

1.  Subfltaiicefl  with  (he  formula  C,^H|„  which  form  addition- 
products  with  only  one  molecule  of  HCl  or  with  two  Br-atoms. 

2,  SubslanoeKwiih  the  formula  C,,H,„  which  form  addition-pro- 
ducts  with  twa  innleeuleH  of  HCl  or  wilh  four  Br-Htoins- 

Some  particubirs  regarding  the  individual  membOTS  are  given 
below. 

Pinene  is  the  ma«t  widdy  distributed  of  all  the  tcrpenes;  it  is 
the  principal  constituent  of  German  and  American  oil  of  turpentine. 
Tlic  Hrst  contains  i-hielly  a  la-vo-rotatory,  and  the  second  a  dextro- 
rotatory, modification.  The  boiling-point  of  this  substvtoe  is 
ISS^-iei',  and  its  specific  gravity  nSB-0-89.  Wilh  nitroayl 
chloride,  NOCI.  pinene  yields  nn  addiiinn-pmducl.  C„H„N'(  ►CI, 
froiii  which  HCl  h  split  off  by  healing  with  alcoholic  piitaali, 
yielding  a  compound,  Cj^H^NO,  niVroaoptnnw.  Thb  can  be 
reduced  to  a  has*-,  C,«HuNH,.  pinylamiite.  whose  hydrochloride  on 
beating  iradily  decomposes  into  aniniunium  chloride  and  cymenp, 
C,«H,4.  Pinene  unili»  with  one  molecule  of  HO  to  forma  solid 
crj-stailine  mafis,  C,„H„C1.  meltitiR  at  )25°;  Ihh  substance  is  calhxl 
artificial  camplior,  and  strongly  re8eml>tes  natural  camphor  in  its 
external  appearance  and  odour. 

On  healing  artificial  camphor,  C„H,^1,  with  anhydrous  flodium 
acetate  and  glacial  acetic  acid  (a  general  method  for  splitting  off 


454 


ORGANIC  CHEMISTRY. 


lw(lroehIi)rif  acid  from  tcrpow?  hydrochloride*),  there  is  formed 
mmphene,  one  of  the  few  fioliil  eonijjomiUs  Jiaviiip  the  ooropoailioti 
C,,lij,.  It  is  cr>-sta.Uine,  melus  al  30°,  and  is  known  both  in  the 
dtrxlro-rolalon-  and  lan'o-nitatoo'  niotlUication!*;  il  has  an  oJmir 
like  tuqx'nt  inc  and  ramjiiinr.  and  is  not  a  natural  pnxlurt.  Oxida- 
tiim  with  chniniic  acid  coiivrrli^  raiiiphcnc  itil<»  camphor.  It  is 
likewise  obtainable  in  the  rcverBc  way  from  camphor:  bomeol  is 
convprl<Nl  rrio  caniplicnc  by  the  spiittiiig  off  of  water.  Camphene 
forms  an  adttiiion-product  with  otaly  one  molfculc  of  HCl,  the  com- 
pound C,«H,,C]  which  is  formed  being  isomeric  with  artificial 
carnplmr. 

360.  Among  the  siibetanntt  C„H,a  \M>ich  add  on  two  molecules 
of  HCl  arul  fuur  bromine  iUmieJimontru  ami  dipenlme  deserve 
^KCial  mcniion.  Limoncno  is  the  principal  constituent  of  the 
etliereal  oil  oblaiiied  from  oranf;c-rind,  and  is  also  present  in  nu- 
merous other  ethereal  oils,  such  as  oil  of  citron,  oil  of  bcTgamot,  etc. 
Dipixitene  appears  to  exist  as  such  only  in  Oieum  n'mr.  but  is 
formiHl  by  heating  limoncne  and  other  Icrpenes  lo  250'  to  300*.  It 
ia.  therefore,  present  in  ethereal  oils  in  whose  preparation  a  high 
tL'injKTalurc  has  been  employed.  a»  is  the  case  with  Ruasian  and 
Swedish  turiKMitine. 

Limonenc  if<  strongly  dextro-rotatory,  and  its  tetrabromidc  is 
also  optically  activo.  On  the  olhpr  hand,  dipi?nleno  and  its  tetra- 
bromide  are  optically  inactive,  ami  the  nddition-producls  w^hich 
Umonenc  and  dipentenc  >*ield  with  the  hydm^n  halidi-s  are 
identical  and  inactive.  The  latter  yieki  dipentcne  by  the  iq-ilitlinK 
off  of  hydrogen  halide,  fto  thai  hinonene  can  in  this  way  be  converte^l 
into  dipetitene. 

Wallach  diHcovcred  in  pine  oil  a  liydnwarlyTU.  Ci„n,fl,  which 
nilales  llit-  plant-  nt  pilarizulion  l»  Hm?  U'fl  to  tlii'  san»e  (^\le-nt  u 
limoncne  to  the  right,  niid  which  fnmi  its  genrral  character  is  to  be 
l<M)kfd  H[>im  HM  thf  ojiliral  antitlu-^ia  of  lirtioncnc.  When  tliis 
laro-Hmomnr.  ia  mi.\nl  with  thr  ih-xlrn-innditirntion,  dipcnti-nr.  is 
form<%l,  from  which  it  followH  that  dipcnleno  is  to  be  regarded  as 
the  racemic  modification  of  t  he  limoricncs. 

Pinene  can  bt-  fonvertwl  into  <iipentene  as  follows.  By  the  actteo 
of  water  containing  nitric  acid,  it  taki's  tip  three  molecules  of  water, 
fonning  lerpiji  Ayt/m/f.  C,„Hs/)^  f  H.O.  On  JM-ating,  this  lows  a 
iiioIwuIl'  of  water,  yielding  Urpin,  CH^Oj.  which    by  the  usual 


45* 


OUGANIC  CHEMtSTRY. 


linkings  in  its  molecule.  It  in  converted  by  oxidation  into  an  alde- 
hyde, C,aH,«0,  gcranial,  nhHwing  that  it  must  be  a  primary  alcohol. 
Geranial  is  sometimes  also  called  citral,  owing  to  its  presence  in 
oil  of  citron.  On  heating  nith  putaistum  pyroeutphate,  eilral 
nt-stly  IoR«*  watiT,  being  converted  into  rvmene,  C,^,,.  Cieraninl 
also  loses  water  when  treated  with  potassium  pyrosulphate,  yielding 
a  tetpene,  C,»H„.  !;<7yiwiVnr,  Ix)iling  between  172*  and  176"-  From 
its  additive  power,  this  rompound  seems  to  contain  three  double 
linkings  in  the  moleaile. 

Closely  relatetl  to  geraatol  are  linaUd  (from  oil  of  linalcts),  and 
rhodincl  (from  oil  of  rosee).  They  have  also  the  formula  C„»H,,0, 
and  are  converle^l  into  nlral  by  nxklation.  This  is  pmhably 
aceompanie«i  by  an  alteration  in  tbe  positions  of  the  double  lick- 
ings present  in  tbe  compound. 

The  ConxtitDtion  of  the  Terpenes  and  Camphors. 

362.  A  coiiipound  C,^„  lias  six  hydrogen  atoms  Ices  t  haii  a  sat- 
urated fatty  liyUnjcarlion  of  ten  carbon  atoms.  C,.Hb.  An  aro- 
matic hydrocarbon  with  saturated  side-chains  and  ten  earlmn  atoms 
has  the  formula  C,oH„.  The  terpones,  thrreforp,  f^<'iii)y  a  poetttoit 
intermediate  between  the  nroniatir  and  the  saluralcd  fatty  scries. 
Their  propcriies  correspond  with  this  view:  on  the  one  hand.  Ihey 
are  leadily  converted  into  aromatic  compounds,  especially  eymene; 
on  the  other,  they  exhibit  many  of  the  properties  of  aliphatic  com- 
pounds. The  difference  of  six  hydrogen  atom?  between  them  and 
the  ^aturatcd  hydrocarbon'!  with  ten  carbon  atoms  nii^ht  liccnu^rd 
by  the  presence  of  three  double  linkings,  which,  indeed,  sceni  lo 
be  preseni  in  gemniene.  .Since,  however,  the  other  terpenes  do  not 
add  six  monovalent  ntom<t,  but  some  only  four,  and  others  only 
two  such  atoms,  they  mu-st  contain  one  or  more  clo-^ed  chains 
of  C-atom<{.  in  addition  to  double  linkings.  As  in  each  rk»ed 
chain  there  are  two  atom?  of  hydrogen  1cm  in  the  molecule 
than  in  the  corresponding  open  cliain  (liexane,  CaH,, ;  hexa- 
mcthylcne,  CaHu).  it  fdlon-s  that  in  the  terpeocs  which  add 
4Br  and  2HCI,  there  nwi^l  Ix*  one  closed  cliain  and  two  double 
linkings;  and  in  the  terpenes  which  add  2Br  and  IFICl,  one 
double  II  nking  and  tw-o  closed  chains.  The  problem  is  to  determine 
which  are  the  ring-systems  in  the  different  terpenes.  and  what  ate 
the  [Hisiiiuiis  of  the  double  linkings  In  the  molecules.     These  two 


CONSTtTUTtON  OF  THE    TERPENES  AND  CAMPHORS.      457 

questkitui  liave  not  yet  been  fta(i}tfacto*-iIy  answ«re(l  for  all  tcrponc-s. 
For  nearly  all,  twu  or  mure  coiislitutioiial  forniulir  have  been  pro- 
potiptl,  aitiuiig  which  no  (leriiiit(>  Sfli-otion  has  Ix^on  inacte  up  t(v 
the  prrsrnl.  Owing  to  the  reailinfss  with  which  many  terpencs 
yicUl  cynicnc,  it  is  supposed  that  the  carbon-nucleus  of  this  com- 
pnutiil,  a  closed  hexagon,  ia  present  in  them,  with  methyl  and 

isopnipyl  in  the  pam-posjtion:    CH, — 'C      / — CH(CH,),.      Tlip 

positions  of  the  double  liiikings  in  this  nucleus  have  been  deter- 
mined for  ter|)enes  which  yield  tctru-additiun-products;  for  sodic 
of  thetn  with  considerable  certainty.  Fnr  example,  tbo  adjoining 
formula  u*  almost  imivrrsnlly  asaJRned  to  limoncno, 
one  of  the  double  liitkiiifis  l)einK  in  the  sido-cliain. 
Tliis  fornnila  explains  the  different  behaviour  of 
the  two  double  linkinjzs,  owing  to  their  V>eing  situ- 
ated within  and  without  the  ring  respectively; 
linionenc  adds  on  only  one  molecule  of  HCI  by 
treatment  with  dry  hydrochloric- acid  gas;  tlie 
serond  double  linkinf;  is  only  bnikeii  by  treatment 
with  mnist.  hydrnphlorie-acid  pas.  [t  furl  her  ex- 
plains the  npliral  activity,  since  ihe  ratbnn  atom 
which  is  marke<l  with  an  asterisk  (*)  is  asymmetric. 

Terpinnlene  also  gives  letra-addilinn-pmdiicts,  and  has.  there- 
fore, two  double  linkings.  One  of  these  is  situated  in  tliccymcnc- 
nucleus,  betwcentwolertiaiy  C-atoipa: 

CH  CH, 

'\_/ 

CH,  CH, 

Terpinclrne 

This  la  proved  by  the  fact  that  Ihiji  body  yields  a  ciystulline.  blue 
addition-pimUict  wUh  nitrosyl  chloride.  This  ia  a  chaiactciisUo 
of  compouitds  which  have  a  <loublc  linking  between  Icrtiaiy  carbon 
atoms  >C=C<,  as  has  been  indicated  in  the  case  of  seveial  such 
substances. 

Compounds  with  the  formula  C,„H„.  which  can  only  take  up 
one  molecule  of  IICl  or  twn  halogen  atoms,  must  have  two  closed 
rings.  A  hexagon  of  carbon  atoms  is  also  supposed  to  exist  in 
Ibcse.    In  the  ca&c  of  pinene  the  second  ring  is  probably  fo.ir-sidctl: 


CH, 

C 
HC/\CH, 

H.cl^/'CH, 

r 

GH,    CH, 

LltD«l)C(IF  ■nil 
dlpcttlTM 


A. 


45» 


ORCASIC  CHBMiSTRY. 


HC 


Baeter  assigns  to  thU  compound 

the  adjoining  formula,  in  wliich  the 
ifiopropyl-grtmp  of  cyniciie  ia  linked 
by  its  tertiary  carbon  atom  with  tlie 
mcfi-carlion  atom  of  llic  tictOKun. 
This  formuin  at  tril)iilrK  two  six- 
sided  rings  and  one  four-sided  ring 
to  pinene.  In  «amphene  the  ter- 
tian,* carbon  atom  of  lh«'  iwii»ni|>yl- 
groiip  13  linknl  t<i  thir  lii'iuwuvriiig  "^ 
at  the  }Mra-pc«ilion,  so  tlmt  it  con- 
tains one  six-si(i<'(l  ring  ami  two 
five-sidcil  rinRK.  Analopoiis  constj- 
tuti(H]al  formula  arc  assigned  to 
the  other  tcrpen<^,  C,(,n,fl. 

383.  It  hiiti  bf-cn  nii-ntjonod  that 
the  fiMmphonf  liave  iho  forniiila  Cj^H^O, 
C,ofr,/>.  C,„n,,0.  MPiithoI  is  an  ex- 
ample tif  a  cotnpniitid  with  thr  first:  of 
these  fonriul8\  It  is  an  alcnliol,  sm], 
accDiilitie;  to  itM  formula,  (;oiitain5  two 
hydrogen  atoms  Itss  than  «  sattiraiwl 
aleohol,  C,^HjjO,  Since  menthol  does 
uul  funii  addition- pnHltict^,  it  muat 
liave  (lie  one  cloMHl-ring  structure. 
Tlie  readiness  of  its  conversion  into 
c>inenc  icidicates  that  it  eontaiiBK  a 
oymeiu>-nucleus,  its  t-oii^litutiou  Uring  expressed  by  the  adjoiaing 
formula. 

A  eompound  with  tho  formula  C,„]I„0  can  only 
liave  an  open  chain,  if  it  ha.s  double  or  treble 
iiuking)!  in  il^  molcculr.  This  is  tiie  case  with 
geraniol,  C,„II,,0,  which  Iul-*  twn  double  Itnkirigs. 
Konieol,  whirh  is  iaoinrric;  with  it,  does  not  jiosscsfl 
any  addilive  power,  and  Jtd  deficiency  in  hydrogen 
compared  to  a  saturated  compound  must  be 
cBiwCKi  by  the  preaeiii-e  of  two  closed  rings,  the 
same  liciug  then  true  of  ordinary  tamphor,  C,»H|^. 
Tlie  oxidation  of  camphor  affords  a  closer  imnght  into  its  consti- 


CH, 

"A 
f 

C.H, 

HmnkAl 


OH 


CONSTITUTION  OF  THE  TERPENES  AND  CAMPHORS.       459 


tution.  Bredt  has  shown  that  the  first  product  obtained  by  its 
oxidation  is  camphoric  add,  which  on  further  oxidation  yields 
camphanic  acid,  the  latter  yielding  camphownic  acid  on  still  further 
oxidation.  It  may,  therefore,  be  assumed  that  the  two  first-named 
acids,  as  well  as  camphor  itself,  have  the  same  carbon-nucleus  as 
cainphoronic  add. 

The  constitution  of  the  tribasic  camphoronic  acid  follows  from 
the  result  of  its  decomposition  when  submitted  to  dry  distillation, 
a  treatment  which  splits  it  up  into  trimethylsuccinic  acid,  isobutyric 
acid,  and  carbon  dioxide.     This  is  accounted  for  by  the  formula 

^g»>C-COOH 
CH,— C— COOH       , 


CH— COOH 

the  formation  of  the  first  acid  being  represented  by  the  decompo- 
sition A,  and  the  second  by  B. 

From  a  consideration  of  these  and  other  known  properties  of 
these  substances,  Bredt  assigns  to  them  the  following  constitutional 
formulae : 


CH,- 


-CH CH, 


CH, 


-CH- 


-COOH 


CH, 


CH,-C-CH, 

-t 


-CO 


CH 
CH, 


.-i-CH. 

C COOH 


CH, 

Camphor 


CH,- 


\ 
\    ■ 
No. 

CH,— C— CH, 


-COOH 


CH,- 


-C- 


-CO 


CH, 

Campboric  acid 

COOH         COOH 

! 

CH,— C-CH, 

CH, C GOOH 

CH, 

CamphoroDic  acid 


CH, 

Camphanic  acid 


The  formation  of  cymene  from  camphor  is  indicated  in  the  fo> 
muia  of  the  latter  by  a  dotted  line,  showing  the  breaking  of  the  car- 


46o  ORGANIC  CHEMISTRY. 

bon  bond  in  such  a  mamier  that  the  isopropyl-group  takes  up  the 
pora-positioD  to  the  methyl-group. 

Recent  work  affords  confirmation  of  the  correctness  of  Bhedt's 
formulifi,  that  of  the  one  for  camphor  being  proved  as  follows. 
According  to  it,  there  are  two  asymmetric  C-atoms  in  the  molecule, 
indicated  in  the  formula  by  bolder  type.  When,  however,  tho 
CO-group  is  transformed  into  CHj,  the  asymmetry  of  both  atoms 
vanishes,  and  the  molecule  must  become  optically  inactive,  pro- 
vided Bredt's  formula  is  correct.    This  does,  in  fact,  take  place. 


364.  The  simplHt  possible  compound  of  tbis  nature  is  oiie 
cnntAioing  lw«  Ix^nzene-nuclei  directly  linked  to  one  another,  la 
addition  to  this  tlifjre  are  nompoundu  in  uhit-li  1l»r  Ix-nzenp^niwlei 
are  indirectly  CDniiecl*d  l»y  a  carbon  atom,  or  by  a  rliain  of 
carbon  atoms.  A  few  of  tliesc  substances  will  be  deacnbcd  in  this 
section. 

Dipheiiyl.C,H,C,H.. 

Diphenyt  can  be  prepared  by  Frmt;'s  sj-nthcfiis  (268)  from 
bromobfnzenc  and  sodium.  Another  method  for  ttio  prcpsration 
of  the  derivatives  of  dtphenyl,  the  conversion  of  hydrazcjbeiiu4ie 
into  benzidine,  was  menlinned  in  891,  On  removing  the  atnido* 
groups  from  benrJdine  by  niesnfl  of  the  diazo-reartiun,  diphenyl  is 
formed.  This  methf>d  of  formation  also  afTonls  a  proof  of  the 
con3tilution  of  benzidine. 

The  iirejiaralinn  <if  diphenyl  is  usually  efTeeted  by  passing  ben- 
zene-vapour throiiph  a  red-hot  tube.  It  is  converted  by  oxida- 
tion inio  beozorc  aeid;  this,  together  with  iis  synthesis  by  FirrKi'a 
methtHl.  is  a  proof  of  itseon.-ititulii>n. 

Diphenyl  forms  larjje,  tabular,  colourless  cryslalTi,  n^adily  soluble 
in  alcohol  and  ether.     It  melts  at  71°,  ami  boil.t  at  '2b-\°. 

The  isomeric  suhslit-iltinn-prnducts  of  dipheuyl  are  much  more 
numerous  than  thn^e  of  Ijenzene;  a  nionosiibstitiilion-pn"iduet  eaii 
exist  in  three  isomeric  forms,  the  sulMiliturnt  being  in  the  orffio: 
meta-.  and  jwm- positions  to  {he  bond  lirtween  the  benzene-nuclei; 
in  a  diaobptitntion-pHKhict,  l>oth  substituenta  may  be  linked  to 
the  same  benzene-nueleus,  or  to  different  Iwnzcne-nuclei,  etc. 

Benzidine  is  of  teelinical  iniporlancc,  because  many  of  the 
azo-dyes  are  derived  from  it. 

461 


463 


ORGANIC  CHF.MISTRY. 


Di  phenyl  methftoe.  C,H,CH,C,Hs. 

368.  DiphenyUnelhane  can  be  obtained  from  benayl  chloride, 
C,HbCI1,CI,  or  from  methylene  chlonijc,  CHjCl,,  by  the  action  of 
bcn?«ne  aiid  ahiniinium  ohloridp,  \\s  lii)iiinlofrii(>8  ftre  obtained  by 
the  octiun  (jf  btnizom*  and  t'niipent rated  siilphtirie  acid  upoa  aldo- 
liydejs;  thus,  aft'taldclivde  yields  ax-diphaiylflhaJte  : 

^"      "  "    CH 

niC.TL  =  <^"_.r^Mii 


CH,-C 


''  ^  h!c;h: 


en,  c<^.«jj^  +  H,o. 


When  derivatives  of  benzene  are  substituted  for  benzene  itself, 
many  derivatives  of  di phony lmetha.iiL'  ran  Ijo  obtained  by  the 
a{>plipaiioii  of  the  syntlitws  just  mentioned. 

OipheiiyliiiL'tliaiif  is  crystalline;  ii  melts  at  2fi*  boils  at  262*, 
and  has  an  ndnur  resembling  that  of  orange-peel.  Oxidation  with 
chromic  acid  converts  it  into  bemophenone  (300). 

A  derivalivo  of  diphenylniQiliitno,  in  whicti  tbd  be D£i>a»- nuclei  are 


■till  directly  Unlced, is^Etomiff, 


c,n/ 


II  is  foriDod  by  leading 


the  vnpour  of  diplicnylmailiant!  throuKli  a  red-hot  tiilw.  It  cry»tallitcs 
from  alcohol  in  lliicrescenl  leaflets,  from  which  ittlerivfaitsnnme.  Ii 
Uielta  at  113*,  and  buils  a.%  293°.  U  jriuldared  uvudles  vtith  picric  acid. 
Tlie  cniigtil(Hii>n  of  niioreii«  \s.  thiix  nxiAbliihod.  U  Is  couvcrted 
by  tho  action  of  oxidiziug-agciits  into  tiiphent/knrkttvne,  wbtcb  ha*J 


tlio  formula 


CO,  Ibis  being  proved,  by  its  TortiiatiDn  when  the 


V 


C<U,-CO|0. 
Ciielnm  soit  ot  diphenie  acid,  {         |         /C;i.  is  distilled.    Diphentc 

c\H,-  icotr 

acid,  for  itn  ]uii-l,  »  obuiiiod  from  »•  bydninobcnxolc  acid  by  tbe  b«aa-j 
tdiiie-tranKroiiiiHlion  cS9li.  ami  ftiibM/i^iicnl  rliminalion  of  ibe  amide 
grouptt ; 

!  Ill 

coon        UOOC       HOOO    COOH 

It  follows  tiiat  the  carhoiijl-gmup  in  diiihenyleiieketoac  is  linlccd  at 

tho  orMo-positioii   la  bolh  thft  bfttiicne-nucloi;  it  hn«.  ihcrefore,  tha 

structure 

.and  Iluoreno  itmelf 


H, 


TRIPHENYLMETHANE  AND  ITS  DERiyATiyES.  4^3 

This  receives  con&rmfttion  from  the  fact  that  pbthalic  acid  ia  the  only 
product  obtained  by  its  oxidation. 


Triphenylmethane  and  its  DerivativeB. 

366.  Triphenylmelhane,  CHCCjHs.),,  is  formed  from  benzal  chlor- 
ide, CflHj  ■  CHClj,  by  the  action  of  benzene  and  aluminium  chloride ; 
from  benzaldehyde  and  benzene  in  presence  of  a  dehydrating- agent, 
such  as  zinc  chloride;  and  from  the  interaction  of  chloroform  and 
benzene  in  prraence  of  aluminium  chloride.  It  crystallizes  in  beau- 
tiful, colourless  prisms  melting  at  93°;  its  boiling-point  is  359°. 

A  series  of  important  dyes,  the  rosanilines,  is  derived  from  this 
hydrocarbon.  Triphcnylmethane  itself  is  not  employed  as  a  basis 
for  their  preparation,  simpler  substances  which  are  converted  into 
its  derivatives  being  used  instead.  The  formation  of  the  dye  takes 
place  in  three  stages;  that  of  malachile-green  furnishes  an  example. 

\Vhen  benzaldehyde  and  dimethyianiline  arc  heated  with  zinc 
chloride,  tetrametkyldiaminotripkenylmethane  is  formed; 


H         ^ 


C,H.-C:|0+jj 


H 


<3>N(CH,),_„(.  ,p„    p    C,H.N(CH,), 


The  carbon  atom  of  the  aldehyde  group,  therefore,  furnishes  the 
"  methane  carbon  atom  "  of  tri  phenyl  met  hane. 

This  substance  is  also  called  leucomalnchile-green.     It  is  con- 
verted by  oxidation  with  PbO,  in  hvdrochlorie-acid  solution,  into 

*.  r  K-     1  C,h1c[C,H,\{CH,)Jj     ....  , 

the  correspondmg  carbinol,         ah  '  "'"'^h  is  a  colour- 

less, crystalline  substance,  like  the  leuco-compound  from  which  it 
is  derived.  Being  an  amino-base,  it  is  capable  of  yielding  salts; 
thus,  it  dissolves  in  acids  with  the  formation  of  colourless  salts. 
When  such  a  solution  is  warmed,  water  is  split  off,  and  the  deep- 
green  dye  produced.  The  latter,  either  as  a  double  salt  with  zinc 
chloride,  or  as  an  oxalate,  is  known  as  malaMte-green.  This  split- 
ting-oft  of  water  may  be  represented  in  several  ways;  it  is  usually 
supposed  to  take  place  thus: 


.464 


ORGANIC  CHEMISTRY. 


C,H,N(CH,),riCl 


i^Hl'^^^^ 


N(CH,),.T1!CI 


-H,0 


C,H,. 


N(CH,),' 


h 


According  to  this  mode  of  reprcfli-ntation,  the  process  is  analogmis 
to  the  fnrmolion  of  quinone  frnm  quinol.  in  which  the  colourless 
quinol  is  convi^rted  into  thedeep-ycllow  quinone. 

The  three  slages  neeessnry  to  the  formation  of  the  dye  fnay» 
therefore,  be  definf^d  iw  f()II(iw"fl- 

1.  Forniatioii  of  a  Icuca-husc  (coJourless),  a  derivative  of 

2.  Formation  of  a  eolour-tiafe  (eoloiirloss),  a  derivative  of 

H0.C{C,H,N1U),; 

3.  Formation  of  ihi^di/e,  a  derivative  of 


p(C,H,NH,-Ha), 


Rcdiiclion  converts  the  dyes  bat-It  u^aiii  into  thfir  Icuco-basea, 
two  hydrogen  utoms  being  tal<cn  upduriii)r  the  reaction. 

Cn/N(«/-i\W('((hcxanietlij'Uriaminotr(phci)ylniiClhiinc)  fumitilirs  an 
cxeellcrit  e\amjtle  of  a  phenomenon  also  exliibili-d  by  other  ans- 
lof!OUE  basic  substances.  When  on  equivalent  quantity  of  a  base  is 
added  to  a  salt  of  crystal -violet,  Uio  liquid  still  remnin>i  coloured, 
haa  u  8troii):  alkaline  reaction,  and  eoaducle  an  clcctrie  current;  Lite 
eohition  sliiwly  hecomes  colourless  or  standing,  wIiph  il  is  no  longer 
ulkaliiii.-,  iind  ile  [Hiwer  of  conduiMinK  an  elcclrio  current  ha*  ceased. 
Tlie  liquid  now  contains  a  colnitr-hrt-sc  Thej*p  [ilinnorneoa  are 
an&logouit  to  the  conversion  of  nvids  into  p^eudo-scidii  (SBl).  For 
this  reason  the  col(iur-bii.se  mny  be  looked  ujion  as  a  pftudo^taxe. 
Accordinc  to  tliis  view,  on  addition  of  the  equivalent  quantity  of 
JIaOII  to  L-rysliil-vioh-t,  the  Inie  hase. 


CCH.),Nt:.H.>C 
tCH,J,N  C.H.     ^ 


— ^Ull 


is  at  first  present  in  thcwJutJon;  this  true  base,  however,  after  ataixl- 
ing  for  several  hours  at  25°,  climiges  into  the  colour-base  (pseudo^ 

base)* 

(CH.>,N  C.H.>p,C\H..\(CH,V 


TRIPHBNYLMETHANE  DYES.  4^5 

Hantzbch  has  been  able  to  assign  the  character  of  a  pseudo-base 
to  certain  substances  other  than  those  mentioned  on  p.  464. 

PararosanUine  is  obtained  by  the  oxidation  of  a  mixture  of 
p-toluidine  (1  molecule)  and  aniline  (2  molecules)  by  means 
of  arsenic  acid  or  nitrobenzene.  The  methyt-group  of  toluidine 
is  thus  converted  into  the  "  methane  carbon  atom ".  of  triphenyl- 
metbane :  , 

X.HrNH,  C,H,NH, 

CH,/ C,H,NH,  +  30  =  HO~C.    C,H,NHj  +  2H,0. 
C.H.NH,  \C,H,NH, 

This  colour-base  yields  a  red  dye  with  acids,  from  which  it  can 
be  precipitated  by  alkalis.  It  is  converted  by  reduction  with  zinc- 
dust  and  hydnwhloric  acid  into  paraleucaniline,  HC(C9H,NHj)j,  a 
colourless,  crystalline  subslancc  which  melts  at  148°  and  is  recon- 
verted into  the  colour-base  by  oxidation.  The  constitution  of 
paraleucaniline  is  shown  by  its  yielding  triphenylmethane  when  its 
amido-groups  are  removed  by  the  diazo-reaction.  On  the  other 
hand,  paraleucaniline  can  be  obtained  by  the  nitration  of  triphenyl- 
methane, and  subsequent  reduction  of  the  trinitro-derivative  thus 
formed.  Paraleucaniline  is  converted  by  oxidation  into  triamino- 
triphenylcarbinol,  which,  like  malachite-green,  splits  off  water  un- 
der the  influence  of  acids,  forming  the  dye : 

C^C.H.NH,         -H,0  -  C^„H^NHi 
i  \C,H,NH;HC1  V',H,:NH,C1. 

OH 

Another  important  dye  related  to  triphenylmethane  is  rosaniline. 
Its  preparation  is  similarly  effected  by  oxidizing  a  mixture  of  aniline, 
o-toluidine,  and  p-toUiidinc  in  equimolecular  proportions  with 
arsenic  acid,  mercuric  nitrate,  or  nitrobenzene.  In  this  reaction  the 
methane" carbon  atom  is  obtained  from  p-toluidine  as  follows: 

NH,  ■  C.H.  ■  CH,  +  C,H/CH,)NH,  /*^'""'  <  N  H, 

p-Toiuidiae  ;:;^''^'S"*'       +30  =  JI0C^C,H,NH,     +2H,0. 

-I-  0,Hs-I\Hj  \CgH,N"H, 

The  hydrochloride  of  the  rosaniline  ba'^c  containing  one  etjuiva- 
lent  of  hydrochloric  a(rid  is  called  niat/enla.    This  siil)stance  forms 


466 


ORGANIC  CHEMISTRY. 


beautiful  green  cn*Eta]«  with  a  metallic  lustre,  which  dissolve  in 
water,  yielding  a  goUilion  of  an  intense  <leep-rpil  cdimr. 

The  colour  of  the  majtenta-sohilicin  is  due  to  the  monovBlrnt 
cation,  (C„H„N,).  becauw  such  sohitions  are  almost  completely 
innised,  a.*<  is  shown  hy  the  slight  incrra'f  of  Ihrir  iimlreiilar  rtin- 
(luclivity  on  (tirtlier  dilutioti,  Momivrr.  the  fioluliims  of  all  the 
tiiajijeiita  salts— ehloride.  bromide,  sulphate,  etc.— exhibit  the  same 
obsorption-spectnini  Ot  solinions  of  ciiiliiriolpcular  enneenlration, 
which  Ih  an  iiHliration  of  the  picwnee  of  a  coiistiluent  common  l« 
all  of  thum  (the  ealion). 

Tbe  BRita  contaiuinji;  three  cqaivnlcntA  or  nclfl  an  j-ellow,  tlie  red. 
monovnleut.  ention  Imrinj^  beoii  cunvcrlcd  into  (lie  jrllow.  triviilRUt 
one ;  MR  II  n-Kiilt.  nt  i  lii«.  iiingnnln  dissulvml  in  otiwss  of  hydnx-hlunc 
ovUI,  (fields  a  nc-nrl>  colourlnB  aolulioii.  Theee  salta  arc,  bowovor, 
v(.<ry  i-cHiJity  liytlrolyxeii,  as  sbown  by  tUe  reappeamnoe  of  ttw  pnI 
colour  when  lliin  suhiUou  in  bjrdrochlorio  acid  is  [louird  inlo  irater. 

Many  derivatives  of  pararosaiiilbie  and  rosaniliuc  are  known,  in 
which  the  hyiiropcii  atom*  of  the  aiiiido-gToii[ts  liove  been  replaced 
by  alkyl-radielee'.  They  are  all  dyes.  The  violet  colour  lMtroiiie& 
dix>]j4>r  an  the  nimihcr  of  methyUf^roiips  present  inerea^e^  {323). 
PenlAmethylpararoisaniline  isHold  under  the  name"  methyl-vinlet." 
'niien  one  hydrngi'U  uloin  in  4>a(^h  nf  the  amido-^Hipit  of  rosanUinc 
18  replace<l  i>y  phj'iiyl,  a  blue  dyr  is  formed,  called  "  aniline^ihie." 

Tli«  »lkyl-giv>U[«  nere  fomierlf  inimdaced  into  pnramaaDitiBe 
ta  th«  ordiuArjr  way,  by  means  of  an  alkj-l  «)doh(li>  or  ereti  iodUl* 
Tlicw  innthai:!*  liave  hing  siiictt  gifeo  pUc«  io  others,  Iwiter  soilnl 
to  tbe  pr*>i>anitiDii  of  (bv  ulkyl-dorivatirct.  Fur  vxitmple.  methyl* 
vtoltt  is  obt»iiii;il  \ij  iliu  oxidxlioii  of  •tlmeiliylaiiiliiiu  with  potiu- 
sium  cblonito  ami  ciipric;  chloride  ;  tbo  mcttiario  carboti  atom  is  to 
tbis  case  obluinMl  from  on«  or  llin  mei  hyl-^roups. 

Aniliue-bloi',  or  tripbetiytrowiiiiline  bydr<x-lilorid«,  isobtafaed  by 
hentiiix  rosniiltinc  wiih  aiialiiieaiid  j>  weak  nci<l.8ucli  as  beanie  acid, 
vrh»r<j  by  r.hc  amido-groupa  iu  the  ro«nnitino  an>  repliio«<]  by  aailldo- 
groups,  (be  ammoiiiA  wl  free  entering  iuto  pumbiDntioii  nilb  the 
acid,  Tbis  procew  is  «XACIIy  analugoait  to  the  fonoatiou  of  dipheoyl* 
aralDft  from  aniline  hydrochloride  aud  aiitttiie  (2fi4). 

367.  Dyes  formed  from  hydroxy! -derivatives  of  triphpnyl- 
mcthanc  arc  also  knon-n,  but  are  much  le$.s  valuable  tbaji  lho«e 
jiiat  dcecril>ed,  on  account  of  their  being  difhcult  to  fix.    Roaotie 


m^ 


TRIPHENYLMETHYL  AND  DIBENZYL  4^7 

CaH,<QTj' 
acid,   q/t-  ti  qtt       obtwned   from  rosaniline  by  means  of  the 

diazo-reaction,  is  an  example  of  such  dyes. 

Malachite-green  and  the  pararosaniline  and  rosaniline  dyes  colour 
wool  and  silk  directly,  and  calico  after  it  has  been  mordanted. 

It  was  stated  in  321  that  the  fixing  of  dyea  upon  vegetable  or 
animal  fibres  must  be  looked  upon  as  a  chemical  combination  of  the 
compounds  contained  in  the  fibre  with  the  dye,  analogous  to  the 
formation  of  snits.  The  following  is  a  proof  of  this.  The  co1our-ba,ie 
of  rosaniline  is  colourless;  when,  however,  wool  or  silk  is  immersed 
in  its  colourless  solution,  it  becomes  gradually  coloured,  as  though 
an  acid  had  been  added.  This  can  only  be  explained  by  supposing 
that  a  conii)ound  in  the  fibre  unites  with  the  colourless  base,  forming 
with  it  a  salt  of  the  same  colour  as  a  solution  of  the  dye  in  water. 

The  phthaleiiis,  dyes  related  to  triphcnylnicthane,  have  been 
mentioned  already  (327). 

GoMBERG  lias  shown  that  zinc  reacts  with  triphenylchloro- 
mc(hane,  yielding  a  compound  with  the  formula  CC9H5)3C.  This 
he  proved  by  analysis,  and  by  the  cryoscopic  determination  of 
its  molecular  weight.  This  compound  can  be  precipitated  in 
crystalline  form  from  a  benzene-solution  by  the  addition  of  acetone 
or  ethyl  formate. 

This  substance,  triphenylmelhyl,  is  very  remarkable,  for  it  is 
the  first  known  instance  of  a  compound  containing  a  trivalent 
carbon  atom.  It  possesses  notable  additive- power;  thus,  it  com- 
liines  at  once  with  the  oxygen  of  the  air,  with  formation  of  a  i>er- 
oxidc,  CCbHj)iCO — O-CCCgHJ,;  it  instantly  decolourizes  iodine 
solution,  yielding  triphenylmelhyl  iodide.  With  ether  it  yields  a 
crystalline  substance  of  the  composition  2(C,Hs),C  +  (CiHj)^©. 


^ 


Bibenzyl  and  its  Derivatives. 

368.  Dibenzyl,  CoH^  •  CH^  ■  CH,  ■  C^H;,  can  be  obtained  by  the 
action  of  sodium  upon  benzyl  chloride: 


C,H,-CH,|CHNa,  +  CI|CH,-C,H,=C,H,CH,.CH,C,H,-K2Naa 

This  method  of  formation  shows  it  to  be  symmetrical  diphenyl- 
clhane.    It  melts  at  o2^. 


468 


trgj^nic  chemistry. 


^ 


■.i 


Symmttriail  diphcrttjUthykm .  C,H.CH:CH-C,H„  M.P.  12.7*, 
ie  usually  callod  ntiibcnc.  It  cnn  be  obtained  in  various  wnyjf,  a 
tX]>icAl  mpthod  being  the  distillation  of  the  phenyl  eater  of  fumaric 
ftcid,  wKich  eliminates  two  molecule!)  of  CO,: 

C,H,|^l-CII:CH-|COjC,[i,  =  L»CO,  +  C.H,CH:CHC,II^ 

Stllbi>ii«  forma  an  &cUlitit>n<^»rwlittct  with  bromtttc,  from  which 
tatan,  CJitC=CC,Hf  '»  oblained  by  splitting  off  2HDr.  Tolan 
can  he  reconverffd  into  stilbeme  by  curprul  rudurtion. 

p-0i«Mii'niM/i7Afnf,  NHj-CiHifH:!'!!  (■,H,-MI„ran  he  nlitaioLil 
by  Irpiitment  of  /i-nit rrtbpnxyl  chloride,  (TH, ("■(!, H,-Nf).,  with  alco- 
holic; [lotit.-'h,  and  siilwcrnicnt  rt-duction  of  (lie  \)-(hniirauiiUn:nc  thus' 
fonnc-d.     It  i»  ihi^l  as  a  butJH  for  t3)e  (nvpuratioci  of  ccrlnin  dyt^ 

Derivativi*«  of  dilx*tuyl  are  (ihtaiii(><l  by  tt>e  coiulons&tk>n  oE 
henaalileliyde  i  n  presence  of  potassium  cyanide ;  tor  ex&mple, 
baizo'iit  U  thus  fortnfd: 

C,H»-C^;^gcc^j  =  C,H,CO  CHOH-CjH,. 

B«nKO>D 

It  has  the  character  of  a  ketone  alcohol,  siiief  U  lakes  up  two  hydro- 
gen  Rtonis,  iiiili    fiinmififin  nf  a  dihydric  kIcoIioI,    hytirobtmain, 
CaHj-CUOH-CllOH  <',Hi;  on  oxJdalicjn  ii  yk-klsu  tlikrtone,  UtuiI, 
C.Hs-COCOC.Hi.     Hcnitoiii  fontuiiis  tin;  K"»up  — CHOH-CO — , 
which  is  prcrril  iti    the  suiiurs  (806).     U   also   l>o^,sps*^eft    proper- 
tics  vharactcristic  of  the  sitgars;  Ihu^i,  it  redures  iin  ulkaliue  copixr 
solution,  and  yields  nit  (j^aione. 

Itenzll  is  a  yellow,  crys.tftl]inf  f-iiUslanfe.      As    a    <likotonc    it' 
unites  wiiK  two  molecules  of  hydravylainiiii-  lo  form  a  »li«»xin»p. 

*M.  Bcntildinzimt  cvists  in  Ilirpo  i-iomcrie  forinH,  Ihe  number 
Oicoreilcally  jjuvi'blc  from  h  con-idcration  of  the  »terc>oi»omcri$ta  of 
nitrog«'n  derivntive.'*  (801):  ^ 

C,H.  C^C  (-.H,       C.H,  G-C  C,H,       C.H.C C.C,H  " 


l! 


NOH   HOK 


J  OH   Hoi. 

fitrtibeusiiaioxl  me 


\0H  NOH 

JnipflllMIlliyiDXllDO 

One  of  lh«e  ositnes  vciy  rMdily  yifhh  iin  unhydritie,  and  is  Ihcr^. 
fore  assumed  to  have  tho  two  hv droxyl-groups  in  close  pruximitv 
the  ityn-fnriniiU.    One  of  (he  oilier  ilioxitncs  is  the  moHt  Kiahl  ■     t 
the  three  compound*,  nnd  mn  be  obtained  by  varioua  tnt>an><-  th 
third  dioxime  ran  be  reudiJy  Iran^formeU  into  this  Ktahlc  modific  ° 


BENZIUC  ACID.  4^9 

tion.  It  is  im>bable  that  the  stable  dioxime  has  the  symmetrical 
or  a?ifi-formula,  so  that  the  ampki-torm.v[&  must  be  that  of  the  un- 
stable modification. 

When  heated  with  alcoholic  potash,  benzil  takes  up  one  mole- 
cule of  water,  undei;going  an  intramolecular  transforTnation^  with 
production  of  hemUic  acid,  a  reaction  analogous  to  the  formation 
of  pinacolln  from  plnacone  (166): 

G^  COCO-CA  +  H,0  =  cS^^^COOH- 

bensllic  Mid 


CONDENSBD    BENZENE-RINOS. 

3T0.  Condensed-ring  catnpoiinds  contain  two  or  more  closed 
cluuns,  with  C-atoinB  common  to  both.  Such  compounds  arc  pres- 
ent in  tlie  higher-boiling  fractions  of  coal-tar  (267),  Next  to  the 
phcaols,  napiiihfiicne  is  the  principal  panstituont  of  the  Kcond 
fraction,  carbolic  oil,  and  of  tlit?  ihiril  fraplinri,  crecsote  oil.  The 
aiithraoeno  oil  contains  anlhractnc  anil  phcnajiihn-nc,  in  additioa 
to  otJier  hyilroparbons.  'I'hvse  three  compounds  and  some  of  their 
derivative;)  will  be  do«cri(x-d  here. 


I.   HAFBTEALEKT.  C,„Ht. 

This  hydrorarhoti  is  present  in  cimsiderable  qiiantilj"  in  cotd-tar, 
from  which  it  is  readily  obtained  pure.  The  cnide  cryHtaU  of 
naphtlialenc  prccipitAtc  on  ctjoUiif;  fniin  the  fraction  panning  over 
between  170°  and  230°,  and  are  se|>arat<'d  from  liquid  impuritie 
by  pressure,  which  are  further  <.'!iiiiiimted  by  conversion  into  noa-i 
volatile  sulphonic  aeids  on  warniing  the  crude  product  with  small 
quantities  of  concentrated  tulpliuric  acid,  and  di&tilling  with  steam 
or  subliming,  when  pure  naplitlialeiie  comes  ovtr. 

It  crystallises  in  shining  plaies.  melting  at  80".  and  boiling  at 
218".  It  is  insoluble  in  water,  but  readily  soluble  in  hot  nieoholj 
ftnd  ether;  it  dissoh-es  to  a  very  email  extent  in  aOd  aJcnhol.  It 
has  a  chorfteteristie  odour,  and  is  very  volatile;  it  is  always  prraent 
in  coal-gas,  whate  illuninating  power  U  to  a  large  extent  due  to 
its  presence.  It  is  extensively  employed  in  the  manufacture  of 
dyes. 

The  formation  of  naphthalene  on  passing  the  x-apcmm  of  manyJ 
compounds  through  a  red-hot.  tribe,  a  proceea  somewhat  simihu'  tol 

ithat  which  takes  place  in  the  retorts  of  the  gas-work»  (S67>,  ex- 

IplatDs  its  occurrence  In  coal-tar. 

470 


NAPHTHALEUB.  47' 

The  constitutdoQ  of  u&phthaJeDe  was  pnn'ed  io  3fi3  io  be 

H     H 

H      H 

Thin  view  iii  eonfirm<vd  by  tite  two  fallowing  syntheses. 

1.  o-XyljIiiiw  bromide  w  canvprteii  by  treatment  with  9odio> 
ethanetctmcarboxylic  ester  tiit«  hydronaptUhakruMraearitaryHe 
eater: 

,ai,]ST     NaC(COOC^,),  .CH,— C(COOC,HJ, 

^CH,Dr      NaCtOOOCjH^,  ^CH,— C(COOC,H,), 

o-Xrlyhn*  brooatil*  ' 

On  .inpunifif.^ition,  t)ii.«  rompniind  ^plit.i  ciif  two  molecules  of  carbon 
dioxide,  forming  ht/dreutaphUioiett^UarliHiTtfiic  arid: 

XH,— CUCOOH 

C^<  1 

^CH.-t'H  CXX)H 

nbotw  silver  salt  rcitdil)'  loecs  t«-o  mvltMruIrs  of  carbon  dioxide  und 
two  atointi  of  hyclroicfn.  yiddin^  iiai>)iihiilcnc. 

2.  On  bcBtinc  jilii-nyli»fjcrotonic  wid  ii  coiivcrt«d  into  a-noph- 
thol,  a  liydraxyl-dcrivativf  of  napIilliiilcDe: 


H     CH 

HO 

Ptieiiyliux-riiUinli:  aclil 


~H,0    - 


CO 

OH 


Nopbthalene  behaves  in  all  respects  as  an  aromatic  hydrocarbon: 
with  nitric  ncid  it  yields  a  iiitro-derivative,  with  sulphuric  acid  a 
eulphonic  acid ;  its  hydroxyl-derivatives  have  the  phenolic  character ; 
the  amino-corapoiinds  undergo  the  diaro-reaction;  etc.  The  great 
reeeniblancc  in  prcipprlJL's  between  benzene  and  naphthaJene  indi- 
cates simUaxity  of  structure,  aud  to  the  latter  is  ajsdgued  the 
formula 


i 


47  » 


ORGAWC  CHBMtSTRY. 


Partial  hydration  converts  the  centric  bonds  in  naphthalene, 
like  those  in  benzene,  into  double  bonds,  since  naphthalene  dihydride, 
C,oH,o.  readily  fotTiis  an  addition-product  with  bniminc,  like  other 
aubstancra  containing  a  doubie  bond. 

3T1.  Naphthalene  yields  a  much  greater  number  of  substitution- 
pnxiuetK  tlian  Ijenzene,  the  riiimber  obtained  eorrosponding  to 
those  tlieoretieally  possible  fop  a  compound  with  the  above  for- 
mula; tliiB  fact  supports  the  constitution  indicated. 

A  cooipouud  of  the  formula 


must  yield  Ivso  isomorie  monosubstitution-products.  Substitutioi, 
can  take  place  at  a  carbon  atom  directly  linked  to  one  of  the  two 
C-atoms  common  lo  both  HngRO.  ■(.  5,  or  8),  or  at  one  of  the  othera 
(2,  3,  6,  or  7).  which  are  also  similar  to  one  another.  Two  series 
of  monoBubetitution-produtts  are  in  fact  known;  those  in  which 
the  hydrogen  at  I,  4,  .5,  orK  has  lieon  replaeed  are  calWl  "-deriva- 
tives; when  liydrngi'n  is  subntiUited  at  2,  3,  S,  or  7,  the  products 
are  termed  ^-derivatives, 

A  gn-at  tmnilHT  of  [|isllbstitutioll-|t^>dll<■l^  Is  possible;  for  two 
similar  subsIitiiL-nts  it  is  10,  and  for  two  di»»iiiiilar  substituents  14: 
many  of  these  have  beca  obtouied.  The  ten  isonwrrs  a«;  denoted 
by  the  numbers 

1:2. 1:3. 1:4. 1  ;5,  l:fi,  1:7. 1:8,  2:3,  2:6,  2:7. 

In  any  other  arrangement  the  grouping  is  identipal  \^■^th  one  ol 
these;  thus,  2:.')  =  1:B.  and   li:0  =  2:7,  p\€.     Knr     three    siiniW 
fiubstitiients  the  mimber  nf  powiible  isomers  is  niiich  Rrt^ater    and 
still  Kreat-er  fm-  three  <lisdimilar  ones.     The  difiubNtitution-proclucls 
witli  the  Hubslilueiits  in  rlie  wanie  ring  are  eallod  ortho    rtivla   and 
jwiw;  when  they  are  in  different  riiijrs,  the  oompovmda    are  usuallv 
disliiiKiiished    by    numlxTs,  or   aomctinies    l»y     letters  •     thiia    "~ 
compound  4:5  1'*  also  intlicatcd  by  *n*' ,  and  one  3 :  6  bv  BS'      Tl 
positions  1:8  and  4:5  are  also  called  the  PTi-pnsJtions  •    in  «■ 


I 

I 


twn  respects  thcso   rpscmble   the   orMa-poationa.    For  ex&m. 
pcn-nap/UhcUcn^icarboxylic  add, 

/^^V-CXK)H 
/^~S~COOH 

reserablw  o-phthalie  acid  in  being  able  to  form  an  anhydride. 

372.  On  account  of  the  great  number  of  isoiiit-rs,  the  orientation 
of  naphthalene  derivatives  is  soinetinies  very  difficult,  and 
positions  occupied  by  the  substituents  in  many  of  those  which  are 
known  are  still  uncertain.  Tlie  same  method  of  orientation  is 
employed  as  for  the  bcnisenc  derivatives,  the  conversion  of  com- 
pounds whose  side-cliaitLs  occupy  unknown  positions  into  utheia 
with  Hulistitiientfi  whosi!  piwititms  have  l«vn  det^rmineii, 

OxidaUoii  is  another  important  aid  in  their  urientalton,  and  ia 
employed  t«  Jetermiiie  whether  the  suhstituents  are  attaehed  to 
the  aoinc  or  to  different  rings,  as  iv<'ll  as  their  pa-ation  relative  to 
one  another.  Thus,  suppose  the  position  of  the  uitrfH-Rroupfl  in  a 
dinitro naphthalene  has  to  be  determined.  If  it  yield*  phihalic 
acid  on  oxidation,  the  two  nitro-gToujiFt  mii.it  be  in  union  with  the 
same  ring,  that  one  which  ha-s  been  removed  by  oxidation.  If  a 
dinitrophthaUc  afid  is  formed,  thiK  ai»o  |imve.H  that  the  two  nitro 
gnjups  an-  linked  to  the  same  ring,  and  ihe  orientation  of  these 
gnnipM  in  this  arid  should  indicate  their  relative  poation  in  the 
naphthalene  derivative.  Lastly,  if  oxidation  yields  a  mononitro- 
phthalic  acid,  one  nitro-grtinp  is  atlnched  to  raeh  rinp,  and  oripnta- 
tioti  of  the  mononilrophlhalic  acid  obtained  will  determine  tha 
position  of  one  of  the  nitrogroups. 

SnbBtitation-prodnoti. 

373.  The  homologues  of  naphthalene — methyl-derivatives. 
ethyl-<ierivativp8,  etc. — are  unimportant;  thry  can  be  prepared 
by  FlTTlc'ti  method,  or  that  of  I' itifDtL  and  Crafts  (288. 1  and  2). 

a.M ethyl naf^hlhiiUiir  is  ii  liquid,  mid  Ix^iln  at'J-J(P'24'J°;  i9-inrthyl-  S 
naphthalene  is  «  solid,  und  inettj'iit  3"."":  both  arc  prwi-nl  in  cotil-lar.  ^^ 
On  oxidation,  they  yield  "-na-phthoU  and  fl-naphlhok  acid  respect- 
ively, which  rpMemble  btTiioIc  sriti  in  tlieir  properties,  and  are  con- 
verted into  naphthalene  by  di^tillstiun  with  lime. 

a-Chtoronaphthalcne  anil  a-bromonaphihalene  are  respectively 
formed  by  the  action  of  chlorine  and  bromine  upon  bcnltng  naph- 


I 

I 

1 


474 


ORGANIC  CHEMISTRY. 


thalene.  Although  their  halogen  alom  is  not  so  firmly  linked 
that  in  monochlnrolimzcnR  or  inonobromobenitene  (86ft),  ihey 
arc  not  decnmiinf'Cil  on  hniling  with  alkalis.  This  also  holds  koixI 
for  Uie  ct)rrcs[njinliiis  ;S-couipoumU,  wluch  are  not  »>blaiii«l  by  th» 
direct  action  of  halogpnfi  upon  naphtlialciie,  but  can  be  pn-parpd 
from  othtT  ,'3-coiiip«mHl«,  HUrh  a.4  ainino-iU'rivalivi's,  sulpho-dcrivtt- 
tivce,  etc..  tn-  thp  iiu-tluHiN  ilcvcribtHl  under  tx>n2cnp  (303,4). 

874.  The  priHliK't  nbtainei]  by  the  action  of  conrentmtpd  nitric 
arid  upon  naphthnlcnc  is  very  inijxirtant  for  thr  oricntatlnn  of  the 
naphthalruc  licrivutivas:  it  is  tr-jiUronaphtfialnic,  SI.P.  (il°,  wliich 
is  provwl  to  belong  to  the  a-serios  by  its  conversion  into  the  same 
naphthol  as  is  obtaiiio<l  from  piieiiylisocrotonic  acid  (370). 

ThL'  position  of  th»?  substiluents  in  a  preat  numbor  of  mono- 
siil)«titution-product!4  can  i>o  determinix]  from  a  knowlodgt;  of  that 
of  lilt*  nitro-group  in  this  nitn_maphihak'ne.  for  the  mtrcv-group 
can  lio  reUucerl  to  an  aniido-groiip.  which  is  rcplatfable  by  numerous 
atoHia  or  groups  by  means  of  the  dittzo-a-action.  If  a  monosub- 
stituted  naphthalene  is  known  to  be  an  n-coinpound,  iis  i!«»mcr 
must  belong  to  the  ;'?-flnrip,«. 

378.  On  heating  niiphthalpne  with  cnncentrated  sulphuric  acid 
at  a  temperatun*  not  excw^^ling  Sif,  the  two  isomeric  miphthalene- 
monosulphonic  acufs  are  fnrmrd;  nt  IfWonly  the,.9-acid  b  obtained 
owing  to  the  conversion  nf  the  a-cnmpound  into  its,?-i80iner.     Btith 
arc  erj'Htalline,  and  vcn,-  hygmjicopic. 

On  fusion  with  caustic  potash,  the  nnphlhalenesulplionic  arida 
are  convened  into  ^)il}ihtl>u^li.C^„H,■OH,  with  properties  very  similar 
to  thow!  of  phenol.  They  art*  presenl  in  eoal-tar.  a-.\'/ipAMof 
melts  at  il.i*.  and  lioits  at  2S2*:  /i-naphlhot  melts  at  122*,  and  boil« 
at  2^".  'Hie  hydrti.\yI-group  in  lhcs(«  r(ini|M)UndK  can  be  replaeod 
much  more  n-adily  ihun  that  in  phenol.  They  di.ssotvp  in  alkalis. 
With  ferric  chloride  /r-niiirliihul  yields  a  flocculent,  violet  prrcipi- 
Ite;  /9-uaphthol  gives  a  green  colouration,  and  a  )>recipiiatc  i»f 
^ff-dinopftihol,  H(J-C,nH,-(",„na'OH.  ITie  violet  precipitate  obtained 
with  a-uaphtliol  is  |3os«b!y  en  iron  derivative  of  a-dinaphlhof. 

376.  a-\aplith>jfaminr.  and  ^^-napfitlDjlammt.  C,yH,XTrj,  eon 
bo  obtained  by  the  reduction  of  the  corresponding  niltu-detivalives, 
but  are  usually  prepared  by  heating  o--na])h1hol  and  ^-naphthol 
n^peetively  with  the  ammnnia  compound  of  xinc  rlilortih-  nr  of 
-alcium  chlori<ie.     rt-Xaphlhylaminc  la  a  solid,  melting  at  StTYond 


SUBSTITUTION-PRODUCTS  OF  NAPHTHALENE.  475 

has  a  faecal  odour;  /?-naphthylaminc  melts  at  112°,  and  is  nearly 
odourless.  A  mode  of  distinguishing  between  tlie  isomers  is  afforded 
by  the  fact  that  the  salts  of  the  'f -compound  give  a  blue  precipitate 
with  ferric  chloride  and  other  oxidizing-agents,  while  those  of  the 
/^-isomer  do  not. 

These  bases  are  of  technical  importance,  since  the  dyes  of  the 
congo-group  and  the  \)enziipurpurim  are  derived  from  tliem,  and  pos- 
sess the  imjwrtant  property  of  dyeing  unraortlanted  cotton. 

Congo-red  is  formed  by  diazotizing  benzidine,  and  treating  the 
product  with  a  sulphonic  acid  of  naphthylaniine;  the  dye  is  the  ao- 
'  dium  salt  of  the  acid  thu»  formed : 

H,NC,H.— C,H,.XH,->aN,-C,H«— C,H,-X,a  +  2C„H,<|^^-> 

Beultllne  BenzitlLaedlazcinlum  chloride      NaplilhytamiiiesuJ 

plioiiii;  acid 

CuDgo-red 

The  acid  it&elf  is  blue. 

The  benzopurpurins  differ  from  congo-red  only  in  having  a 
methyl-group  attached  to  each  benzene-nucleus  of  the  benzidjne- 
group. 

377.  Some  polysubstituted  naphthalene  derivatives  may  be 
mentioned. 

Dinitro-a'Tiaphthol  is  obtained  by  the  action  of  nitric  acid  upon 
the  monosulphonic  or  disulphonic  acid  of  'f-naplitliol.  Its  sodium 
salt  is  Martius'  yellow;  it  dyes  wool  and  silk  directly  a  golden- 
yellow.  Nitration  of  (c-naphtholtrisui phonic  acid  yields  dinilro- 
naphtholsulphonic  acid,  whose  p<:)tasMiuni  salt  is  naphlhol- yellow; 
it  resists  the  action  of  light  better  than  Martins'  yellow. 

Naphlkionic  acid  is  one  of  Jhu  longest  known  naphthalene  deriva- 
tives: it  is  I'.^naphthyluminesiilphonic^dd, 


NH, 

and  results  from  the  interaction  of  a-naphthylamino  and  stdphuric 
acid.     It  is  crystalline,  and  only  slightly  soluble  in  water;  it  is 


476 


ORGANIC  CHEMISTRY, 


manufactured  for  the  preparation  of  conRo-rcd  and  other  dyea. 
Sohitiors  of  its  Bailw  liiRplay  an  iiitrnat;  n-ddisii-blue  fluorescence. 

a-Naphihaquinone,  ^.',^,lUO,.  i?  formed  by  the  oxidation  of  many 
tf-dcrivativf-B,  and  of  sonic  diderivativos,  of  naphthalcnp.  It  is 
usually  prepared  from  naplithaleiie  it«e]f  by  oxidation  with  a  boiling 
fiolullon  of  chromic  acid  in  glacial  acelic  acid,  a  motliofl  of  formation 
which  has  no  parallel  among  lliose  for  the  preparation  nf  thr  mr- 
reapriiding  benzene  derivatives.  It  rr>'stallize3  from  alcohol  in 
doep-yellow  noodlca,  melting  at  125°.  It  resembles  benzoquinonc 
not  only  in  colour  but  in  it«  other  profwrties;  thus,  it  has  a  char- 
acteriiitie,  pungent  odour,  and  is  very  volatile,  eubtiniing  readily 
at  100" ;  it  is  easily  reducetl  tu  a  dihydroxynaphthslene  by  sulpbur- 
ous  acid.     For  these  reasons  the  structural  formula 


0 


H 
J 
U 


is  assigned  to  it,  analogous  to  that  of  benzoquinonc.  In  support 
of  this  view  is  the  faet  that  on  oxidation  it.  yields  phthalic  acid, 
proving  both  oxygen  atom-s  to  be  attachecl  lo  the  same  ring:  more- 
over, hydroiylamine  converts  it  into  an  oxime.  Knowing  the 
cnnstitution  of  a-naphtharininone  ta  be  1:4,  it  is  possible  to  deter- 
mine that  of  other  diderivntives.  If,  cm  oxidation,  ihey  yield  this 
quinone  by  elimination  of  the  substiluents,  the  latter  must  occupy 
thcpflra-position. 

{i-Saphtkaqitmnne,  CjoHaO,.  is  formed  by  the  oitid&tioQ  of  atnioo- 
naphthol  ( 1 : 2"'  which  proves  its  structure  to  be 


O 


o 


Its  properties  arc  very  different  from  those  of  the  «-quinonc.  It 
crystalliiefi  in  red  ncetUes,  and  decomposes  without  melting  at  115®, 
being  therefore  noti-volatile;  it  is  also  odourless.  Sulphurous  acid 
reduces  it  to  1 : 2-iiihydroxynaphthaleue. 


ADDITION-PRODUCTS  OF  NAPHTHALENE.  All 

Addltion-produoti. 

378.  Naphth&lene  and  its  derivatives  yield  addition-products 
somewhat  more  readily  than  the  benzene  derivatives.  The  best 
known  are  those  formed  by  the  addition  of  four  monovalent  atoms, 
such  as  hydrogen  or  chlorine.  It  has  been  proved  by  the  oxidation- 
method,  and  in  other  ways,  that  the  four  atoms  are  always  added 
to  the  same  ring. 

On  passing  chlorine  over  naphthalene  at  ordinary  temperatures, 
there  results  naphthalenetetracfUoride, 

H    Ha 

hOO-' 

H     HCl 

a  well-crystallized,  colourless  substance,  melting  at  182°.  On 
oxidation  it  yields  phthalic  acid,  and  is  converted  by  alcoholic 
potash  into  dicMoronaphtkalene,  CioHgClj. 

On  reduction  with  sodium  and  boiling  amyl  alcohol,  /?-naphthyI- 
amine  yields  a  tetrahydro-derivativc,  C,oH,,NHj,  a  compound  with 
most  of  the  properties  characteristic  of  the  aliphatic  amines:  it  is 
strongly  alkaline,  absorbs  carbon  dioxide  from  the  air,  has  an 
ammoniacal  odour,  and  cannot  be  diazotizcd.  All  four  hydrogen 
atoms  are  in  union  with  the  same  ring  as  the  amido-group, 

H     H, 


H     H, 

ance,  on  oxidation  with  potassium  permanganate,  this  substance 
is  converted  into  o-hydrocinnamiccarboxylic  acid, 

p  „    .CH,CH,.COOH 
^»"*^COOH 

which  must  evidently  result  from  a  tetrahydro-derivative  with  the 
above  structure  if  the  oxidation  takes  place  at  the  C-atom  linked 
to  the  NHj-group.  Moreover,  the  hydrogen  addition-product  does 
not  take  up  bromine,  another  proof  that  the  four  H-atoms  are 


47* 


OflG^NfC  CHFMISTRY. 


atteched  to  the  same  bcniPQe-nucleUB.  The  entrance  (rf  two  liytlro- 
gen  atoms  int^)  eiLch  ring  niuitt  produce  a  compound  with  double 
boncb,  which  woiilcl  yield  an  addiliou-product  with  bromine. 

The  cinnplctr  irKcniblancc  Ix-twifn  /?-t<'trahy(iroiiaphthylttmine 
and  the  aliphaltp  atnitiPB  is  anttthpr  conliniiatiou  of  the  view  that 
the  ring-stnioture  does  not  in  itself  occasion  any  marked  peculiarity 
in  the  chfiiiical  prnpi^rtips  of  a  compound  (262).  This  compound 
may  lie  looked  iipoi!  as  benxene  with  a  saturated  side-chain, 
—CH, ■  CH, ■  CII(Nir,)  ■  CK,—,  linked  to  two  orfAo-C-atonia. 

o-N'aphthylaiiiiiic  ran  alw>  1>l>  reduced  by  aniyl  alcohol  and 
Bodiiun,  but  the  tHrahydro-dmvative  formed  is  quite  different 
from  that  ohtaincil  from  ;?-iiaphtliylaniiiie,  for  it  possesses  all  the 
propertieif  characleriatic  of  llie  aromatic  amines:  it  can  bo  diaxo- 
tized,  and  lia*  not  au  ammoniacal  odour.  Since  it,  too,  docs  not 
form  an  additioa-pirieluct  with  bromine,  its  constitution  is 

fl.  .    B 


This  proves  that  the  four  hyiirogen  atoms  in  it  also  are  in  union 

with  Ihe  same  nucleus,  but  not  the  one  linked  to  the  aniido-group. 

In  support  of  tlus  are  iu  completely  aromatic  character,  and  the 
hfact  that,  on  oxidation  with  potassiuiit  pennanganate,  the  ring 
■"  containing  the  arnido-group  is  removed,  with  formation  of  sdipic 

acid  CIM), 

CHa 

/\ 
CH,  COOH 


CHjCOOH 
CH, 


Tetrahydrv-a-naphtkjflaminf  must,  therefore,  bo  looked  upon  as 
aniline  contfunins  a  saturated  side-chain, — CHj-CHj-CHj-CH, — , 
linked  to  two  ort/i*>-C-al«m3. 

n.  AllTH&aCEirE.  Ci,Uia' 
379.  Ardhracenc  is  present  only  in  small  proportions  in  coal* 
tar,  the   percentage  varying  between  0-25  and  0-*5  per  cent; 


ANTHR/tCENE.  479 

* 

notwithstanding  this,  it  is  the  basis  of  the  manufacture  of  an 
important  dye,  alizarin  (388  and  383), 

By  fractionation  of  anthracene  oil  (287),  the  so-called  "60  per 
cent,  anthracene"  is  obtained;  this  is  mixed  with  one-third  of  its 
weight  of  potassiiun  carbonate,  and  distilled  from  an  iron  retort. 

O  TT 
This  removes  certain  impurities,  among  them  carbazole,  ■'    *  >  NH, 

C.H, 

which  is  present  in  considerable  proportion  in  the  crude  anthracene, 
and  is  thus  converted  into  a  non-volatile  potassium  derivative, 
(CeHj),N  ■  K.  The  distillate  consists  almost  wholly  of  anthracene 
and  phenanthrene,  which  are  separated  by  means  of  carbon 
disulphide,  in  which  only  phenanthrene  is  soluble.  On  crystalliza- 
tion from  benzene,  the  anthracene  is  obtained  pure. 

It  crystallizes  in  colourless,  glistening  leaflets,  with  a  fine  blue 
fluorescence;  it  melts  at  213°,  and  boils  at  351°;  it  dissolves  readily 
in  boiling  benzene,  but  with  difficulty  in  alcohol  and  ether.  With 
picric  acid  it  yields  a  compound  C„H,,-CjH,(NO,),OH,  which  melts 
at  138°. 

Various  modes  of  preparing  anthracene  are  known  which  give 
an  insight  into  its  constitution.  One  of  these  is  its  syntheas 
by  AfJscHiJTz's  method  from  benzene,  aluminium  chloride,  and 
tetrabromoethane ; 

BrCHBr  /CH\ 

C,H,+       T  +C,H,-C^/T     >C,H, +  4HBr. 

BjrCHBr  X;h/ 

This  proves  that  anthracene  contains  two  benzene-nuclei  imited  by 
the  group  CjH„  a  view  further  supported  by  its  formation  on  heat- 
ing o-tolyiphenylketone  with  zinc-dust: 

From  this  it  follows  that  the  CjHj-group  is  linked  to  ortAo-C-atoms 
in  at  least  one  benzene-nucleus;  the  formula  of  anthracene  may, 
therefore,  be  written 

()l^«>O.H,. 


48o 


ORGAmc  CHEMISTRY. 


The  central  group  C,II,  U  also  linked  U>  orlho^-a\cms  in  the  aeeond 
beiiKene-nucIciiB.  This  ie  proved,  for  example,  by  the  synthesis 
of  anitirnociip  from  o-lmmHibonzyl  hmmido  and  fiodiuiii.  in  which 
a  diliydrtxJorivattve  Li  first  fcirnieti,  awl  ifi  ri-adily  converted  itito 
anthracene  bv  oxiiialion : 


a 


jBr    Na,  Br|H^ 


CH,[BrNajBr 


»3rcinM(benirl  liromlil* 


CH, 


4Nanr  + 


CH 


-2H 


CH, 


CH 

AntbrscviK 


This  conatitiitioii  Indii-ateR  that  niithracene  should  yield  a  very 
larfie  mimljor  nf  is(inn?ric  mibstilulion-pro<lucts,  that  of  the  mono- 
subHtitutiftQ-pnxlucta  being  three.  N'lmiberiug  the  carbon  atoms 
thus, 


then  I  •=  4  =  5  =  8,  2  =  3  =  6  =  7,  and  9  =  10.  Fifteen  dtEuiv 
stilulion-products  with  similar  grt)ii[w  are  jmssible.  A  verj*  cotiaid- 
erabte  nunilxT  of  anthnu-rnr  derivatives  is  knmvn,  ulthmigh  it  is 
small  in  comparifton  wit.h  the  t-jiormoiis  number  theoretically 
possible. 

The  orientation  of  the  anthraecro  derivatives  is  effected  simi- 
larly lo  llwfie  of  riaphlliaU-iie  (372),  uxidatiuu  and  a  study  of 
resulting  product*  being  an  important  aid.  '^    gl 

Sulxtitntion-piodactt. 

380.  Anthraqurnone,  C„H,Oj,  Is  one  of  the  most  impor 
derivative*  of  antbraeene,  from  which  it  is  obtairietl  by  oxidation 
with  snch  agcnlts  &s  nitric  and  chromic  acids.  Authrareiic  is  so 
readily  converted  into  anthraquinooe  by  nitric  acid  that  it  is  not 
possible  to  nitrate  it. 


ANTHRAQUINONB,  48 1 

Anthraquinoixe  is  proved  to  have  the  struetiire 

CO 


CO 


since  it  is  formed  by  the  interaction  of  phthalic  anhydride  and 
benzene  in  presence  of  a  dehydrating-agent  such  as  aluminium 
chloride: 

C.H,<gg>|0  +  H,|C.H,  =  C^<gg>C,H«+H,0. 

Fhtballc  aubydrida 

This  reaction  takes  place  in  two  stages:  o-benzoylbenzoic  acid, 

CO- P  H 
CeH,<p„^j}   *,  m  first  formed,  and  loses  one  molecule  of  water, 

forming  anthraquinone : 

CO 

C^./^CeH,  -  H,0  =  C.H.<^>C^. 
X;00H  ^^ 

Itl.  The  central  group  in  anthraquinone  can  be  proved  to  be  in 
union  with  two  o-C-atoma  in  each  benzene-nucleus — another  proof 
that  the  same  \9  true  of  anthracene.  The  same  method  is  em- 
ployed as  in  the  proof  of  the  constitution  of  naphthalene  (US) :  one 
of  the  benzene-nuclei  is  distinguished  by  the  introduction  of  a  sub- 
stituent,  so  as  to  identify  the  one  broken  by  the  oxidation. 

On  treatment  with  benzene  and  aluminium  chloride,  bromo- 
phthalic  anhydride  reacts  like  phthalic  anhydride,  yielding  bromo- 
(mikraquinone  by  elimination  of  water: 

I       CO  "  I   '  « 

Br.C^,<S>0  -»  BrC.H./'^C.H.  ->  BrC.H,<^>C,H,. 

Bromoan  ibraqulnatie 

Since  thia  compound  is  derived  from  phthalic  acid,  the  two  00- 
groupe  must  be  substituted  in  the  or(Ao-position  in  nucleus  I,  Its 
Br-atom  can  be  replaced  by  a  hydroxyl-group,  by  heating  with 
potassium  carbonate  at  160°,  and  the  kydroxyanthraquinone  thus 
fonned  oxidized  by  nitric  acid  to.  phthalic  acid,  the  formation  of 


48>  ORGANIC  CHEMISTRY. 

which  {troves  aucloua  II  to  li&\e  been  unacted  upon,  aad  to  be  alM> 
substituted  in  the  orthO'^tmHoia: 


U 


u 


HOCtH|<  (Y%'**'t"»  HOfTl^     •    •' 


PbiluJi«Hid 


The  constitutional  rormuln  or  unthraqiuitone  indicates  that  onljr 
two  isomeric  morniFiibslitiition-prodiicts  are  po»iible,  This  has 
been  verified  by  eKperimeiit — a  further  proof  that  the  formula  is 
correct, 

382.  Anthraqmnoiic  cr>'St&IUzcs  from  glai-ial  lurctic  arid  in  light- 
vrIIow  neodlt'S,  mcltinK  at  277°,  At  higher  teinp<TatiiiTa  it  sub- 
limit very  readily,  foriiiinK  '"UK.  sulphur-yellnw  prisnis.  It  is  vcr>- 
stable,  and  is  not  easily  attacked  by  oxidiBing-ogents,  or  by  con- 
centrated nitric  or  sulphuric  acid. 

The  name  Rwihraqmntme  is  in  snmo  mensiire  ineorroct,  for  this 
substance  lacks  some  nf  the  pro|KTties  characteristic  of  quiuopcs, 
such  as  ready  reduction,  great  volatility,  pungent  odour,  etc..  aud 
has  much  more  the  charanter  r>f  a  diketnnr.  M'ith  fiised  caustic 
potash  it  yields  benzoic  acid,  and  with  hydroxylaniinc  an  oximc. 
On  warming  with  zinc-dust  and  caustic-soda  solution,  it  forms 
ioanthraTuA, 

CHOH 

which  in  alkaline  solution  is  converted  into  anthraquinone  by  atmo»> 
pheric  oxidation.  Oxaiilbronot  dissolves  in  alkalis,  the  solution 
having  a  deep  blood-red  colour. 

This  property  of  oxaiitlirunol  makes  its  formation  a  delicate  test 
for  anthrafjtiiiione.  It  is  carried  out  by  wanninft  the  i<ubdtaQOC  to 
1m  tested  will)  Einr-dit5t  and  caustic-soda  Holminn;  IT  nntliniquinone 
is  present,  a  blood-r«l  colouration  is  developed,  and  in  destroyej 
by  shaking  up  the  mixture  witli  air. 

Oxygeii  is  rendered  "nctivo"  (8M)  in  the  oxidatioa  of  oxan- 
thranol,  hydroRen  prroiidc  b»'ing  formed  in  addition  to  anthraqui- 
noac.  Afl  in  other  instancea  of  oxygen  being  rendered  active,  for 
every  atom  of  oxygen  employed  for  oxidation,  one  atom  i«  used  up- 
in  the  formation  of  hydrt^cn  pnoxide. 


ANTHRANOL  AND  ALIZARIN.  483 

On  reduction  with  tin  and  hydrochloric  acid,  anthraquinone  is 
converted  into  anihrarwd, 

a  substance  of  weak  phenolic  character,  which  is  slightly  soluble  in 
cold,  and  readily  in  boiling,  alkalis.  Its  formation  is  to  be  looked 
upon  as  resulting  from  the  splitting-off  of  water  from  an  interme- 
diate product,  a  dihydric  alcohol; 

•    *^C0       "^*         ■    *^Ch|OH|  '^^^    *      W"4C    1  >t^sii«- 

AfithraquiDOnB 

AmnraDol 

When  anthraquinone  is  more  strongly  reduced,  by  heating  with 
zinc-dust,  it  yields  anthracene. 

Alizarin,  or  dihydroxyanthraquinone,  is  the  most  important 
derivative  of  anthraquinone,  and  is  a  dye  of  a  splendid  red  colour. 
It  was  formerly  manufactured  from  madder-root,  which  contains 
a  glucoside,  rvberythric  acid,  C„HjgOn,  yielding  glucose  and  alizarin 
on  boiling  with  dilute  sulphuric  or  hydrochloric  acid;  but  it  is  now 
prepared  almost  whoUy  by  a  synthetical  method.  It  is  one  of  the 
or;ganic  dyes  known  to  the  ancients. 

In  preparing  alizarin,  the  anthracene  is  first  oxidized  to  anthra- 
quinone with  sodium  dichromate  and  sulphuric  acid.  Heating 
with  concentrated  sulphuric  acid  at  100°  converts  various  impiui- 
tiea  into  sulphonic  acids,  the  anthraquinone  remaining  unchanged; 
on  dilution,  these  sulphonic  acids  dissolve,  so  that  pure  anthra- 
quinone is  left  after  filtering.  This  is  then  heated  to  160°  with 
fuming  sulphuric  acid  containing  50  per  cent,  of  sulphur  trioxide, 
the  main  product  being  the  monosulphonic  acid.  Its  sodium  salt  is 
only  slightly  soluble  in  water,  and  separates  out  when  the  acid  is 
neutraUzed  with  sodium  carbonate.  On  fusing  with  sodium  hydrox- 
ide, the  sulpho-group  is  replaced  by  hydroxj-l.  A  second  hydroxyl- 
group  is  simultaneously  formed,  its  production  being  considerably 
facilitated  by  the  addition  to  the  reaction-mixture  of  potassium 
chlorate  as  an  oxidizing-agent: 


484 


ORGMMC  CHEMtSTRY. 


,00. 


C^,<^>C3,SO^ft  +  3NnOH  +  O  => 

Sodium  aii(Ikr»i|iil[iaDo- 

-  C,H,<^>C,H,(ONa),'+  2H,0  +  Na^^ 


The  dyo  is  set  f roe  from  the  sodium  s*lt  by  ailditton  of  an  acid. 

Alizarin  crystallizfs  in  red  prisins,  and  siiMimes  in  orange 
needles,  mt-lting  at  2Sl)''-290';  it  is  nearly  insoluble  in  water,  and 
sliKhtly  Bolnbk-  in  alcotmi.  Oti  account  of  its  phenolic  character, 
it  dissolves  in  alkalis.  It  yicldfi  u  diacctatc.  <Jn  distitlatioD  vntii 
jsine-diLst.  it  is  cwnvertwl  into  anthracene,  a  reaction  which  gave 
the  fiisl  iiisi^ht  into  the  eonstitution  uf  nlizarin. 

Tlie  value  of  alixariii  as  a  dye  depends  upon  its  power  of  forming 
fine-culourei.1.  Ini^oUihie  compound-s,  called  iakts,  with  metallic 
oxidw.  Wlien  a  fabric  is  mordant*fl  with  one  of  these  oxides,  it 
van  Im*  dytti  with  alizarin,  the  colour  depending  on  the  oxide  used. 
The  ferric  oxide  eoniptiuml  of  alizarin  is  violet-black,  the  chromium 
oxide  coinpoinid  claret-colour,  the  calcium  oxide  compound  blue, 
the  aluminium  and  tin  eom|Hiuniis  various  sliaden  of  red  (Turkey- 
red),  etc. 

383.  Hie  method  by  whii;h  alizarin  is  prepared  proves  it  to  be  a 
<ierivativp  nf  anthraqiiinnne,  but  it  haa  now  U»  bii  deterinincil  what 
poKitiotw  the  hydrnxyl-Rruups  occupy.  The  formatioii  of  alizarin 
when  phthalic  onhydri<le  is  heated  at  1.50"  witJi  catechol  and 
Bidplmrie  arid  proves  lliom  tn  be  in  the  same  benzene-micleiis;  and, 
since  till-  liydroxyl-groujw  in  catechol  occupy  the  o-jxwition,  tJie 
same  must  be  true  of  alizarin : 

Phthkllc  Auhydrldo  Oalei-hal  AN/nrtn 

It  follows  that  the  choice  lies  between  the  two  structural  formulffl 


PHENASTHRENE. 


485 


The  result  of  nitration  prov«s  that  fonnula  I  is  correct.  Two 
isomeric  niononitro-derivalives  are  oblained,  with  the  nitro-proiip 
in  the  same  micleus  as  the  hydroxyl-groupe,  since  both  can  bo 
oxidized  to  phlhalic  aeitl.  Foimula  1  alone  admits  of  the  formation 
of  two  such  mononitro-derivatives.  and  must  therefore  be  correct. 

Other  liydroxyl-dt-riviil  ivfs  of  snihrnqninone  nrp  nlxo  dyes. 
This  ifl  so  only  when  two  hydroxyl-groups  arc  in  the  o-po»ilion  to 
one  anothpr.  In  addition  to  these,  derivalivts  of  anthraquinon* 
cnntainitiK  liydro\yl-gri>ijp8  and  amido-Kraups,  or  only  amido- 
groups,  are  also  valuable  dyes. 


in.   prekahth&ekg.  o„h„, 

384.  Phfn'fintkrene  is  isomeric  with  anthracene,  and  is  present 
with  it  in  "anihracene  oil,''  they  arc  sppsratrd  by  the  nidhocl 
already  drei-ribcil  (379).  It  crystallizes  in  colourk-ss.  lustruus 
plates,  which  dissolve  in  alcohol  more  readily  than  anthracene,  the 
solution  having  a  blue  fluorescence.     It  melts  at  90%  and  boils  at 

On  oxidation  with  chromic  acid,  it  yields  fiiat  phenanUira- 
j^ijMne  (p.  486),  anil  then  diphcnic  acicl  (3W), 

Tliis  proves  that  phenanthr^'ne  poswpssfs  two  benzene-nuclei  directly 
linked  to  one  annthor,  and  is  thcrefdro  a  diphrnyl  derivative,  and 
also  a  di-ort/io-coiiipfHind.  Uiphenyl  with  two  hydrogen  atoms 
substituted,  — C„ll,t'nH, — ,  or  — C,.H, — ,  differs    from    phenan- 

i  thrent  by  C..H,.    This  must  link  together  two  (^-positions,  30  that 

L         phcnanthrcne  has  the  constittnion 

L         This 


/ 


This  structure  finds  support  in  the  conversion  of  atilbene  into 


486  ORCAmC  CHEMISTRY. 

pKenanthrene,  on  passing  its  vapour  through  a  K-d-hot  tube,  a 
method  of  forinati{>n  analogous  to  that  of  iliphonyl  from  benz- 
ene (361): 

CH-CJl^  CH-C,H, 

\  -H»  =  T|         I      . 

CH-CeH,  CH-C^. 

8t  II  bMiH  PlieiiaaUiriina 

It  is  seen  from  the  above  const  it  iiticmal  fammla  that  the  group 
CH :  CH,  which  is  unitcil  with  four  C-aloiiis  nf  <Uphriiyl,  Uius  yiehls  a 
fresh  ringofsixC-atoiiis.  Thi; question  arist'S  whclhrr  thin  Ih&  tnir 
bcnzcnc-rinf;;  if  it  is  not,  the  link  C,H,  must  bo  assumed  to  contain 
B  dttiible  bonJ.  This  ciiicslion  is  diEficult  to  answer.  On  tho  one 
liaml.  phpnanlhrpne  displays  aromatip  properties;  for  example,  its 
yielding  phenanthraquinone.  which  resembles  other  quinones  in 
being  reducal  by  sulphurous  acid  to  dihydroxyphenanthreoe, 


C,H,— C-OH 

II 
.— C-OH 


C.H.- 


the  existence  of  a  hrnmophenanthrene.  in  which  tlie  bromine 
atom  is  very  firmly  Hnkr-d,  and  is  nut  attaclced  by  alcoholic  potash 
at  170*.  and  whose  structure  \s  proved  by  ita  oxidation  to  phenan- 
thraquinone to  be 

C,H,— CBr 

I       II   ; 

CaH— CH 

and  the  fact  that  phcnanthrcne  is  not  acted  upon  by  Baeyer's 
reagent  for  double  bonds  (123):  aH  point  to  the  aromatic  character 
of  this  ring.  On  the  other  hand,  however,  the  ^loup  C,H,  adds  on 
bromine  very  readily,  and  is  attacked  when  pheiianthiene  is  oxi- 
diaed — reactions  characteristir  of  an  ordinary  unsaturated  group. 

C„H— CO 
Pkenanthraquinonf,    \  |    ,    is  a  ytllow,   erj'Stalline   sub- 

C.H.-CO 
Btonce  melting  at  200^,  ami  boiling  without  dernmposition  above 
360*.    Its  (likelonic  chaiat'ter  folltms  from  its  yielding  dideriva- 
tivcs  with  sodium  hydrogen  sulphite,  and  with  hydroxy lamine.     It 
b  odourless,  and  non-volatile  with  steam. 


FLUOMNTHENE,  PYRENE,  AND  CHRYSENE. 


487 


IT.  TLTTOXAiriHSirB,  FTBSHX,  AXD  CEB7IBHX 

3tS.  Other  hydrocarbons  possessing  condensed  rings  and  a 
greater  number  of  carbon  atoms  are  also  known.  Among  theae 
are  fiuoraTilhene,  C,,H,u  with  the  formula 


pyrene,  Ci^i^  with  the  probable  formula 


and  chryaene,  Ou,  H,,,  with  the  formula 

C,H4— CH 

CjgHf — CH 

These  compounds  are  present  in  the  coal-tar  fractions  coming  over 
above  360°,  and  also  in  a  peculiar  substance  called  "stubb-fat,"  ob- 
tained in  the  distillatioa  of  mercury  ores  from  Idria. 


HETEROCYCLIC   COMPOinfDS. 

S88  Hie  compounds  hitherto  conddorpd  all  contain  a  ring  of 
i.earbon  atoms  only,  aiul  can  be  cla!*siil  tof;i'tVier  under  the  name 
Ihomocifclif  conjpouiKls,     It  was  ineiitioncJ  in  259  that  riug-systeros 

arc  also  known  posseesing  not  only  carbon  atoms  but  also  those  of 
k  other  ek'ments.  Sulwtances  rnntaitiing  ring?  of  this  kind  are  rlaJ<»('d 
'  together  aa  hticrocyclie  compounds.    A  few  of  these  and  their  <leri\'a- 

tives  will  be  considered. 


I.     FTBIDINE,  CjH.N. 

Pyridine  and  some  of  its  homologues  arc  eonstiincnts  of  coal- 
tar.  On  mixing  the*'liglit.  oil"  (267)  with  Bulphnrie  acid,  they 
absorbed  by  the  latt{>r.  and  separate  on  nddiiion  nf  }>ndiuni  rar-^ 
bonatc  in  the  form  of  a  dark-brown,  basic  nJI,  from  which  pyridine 
and  its  homolognrs  are  obtained  liy  fTartionaJ  diiil illation.  Pre- 
pared by  this  method,  pyridine  is  never  quite  pure,  aliiv'a>'S  con- 
taining small  proportions  of  ilH  homoloj^ies. 

Another  source  of  pj-ridine  is  "  Dippel's  nil ,"  a  liquid  of  extrpmely 
diaagroeabie  odour,  obtained  by  the  dry  distiltalion  of  boneu  nhieh 
have  not  been  deprived  of  their  fat.  It  is  a  very  complicated  sul>- 
6tance.  contnining.  in  addition  to  the  pyri<line  bases  and  qiiiitnliDe, 
many  other  nubatanccs,  nucli  as  nitriles,  amines,  and  hydrix-arbons. 

Pyridine  is  a  colourless  ltqui<l  boiling  at  Ilo^,  and  with  a  spes:ific 
E|gravily  of  1  0033  at  0*;  it  is  niiseible  with  water  in  all  proportions, 
has  a  strongly  alkaline  reaction,  and  a  very  charaeieriKiic  txlour 
reminiscent  of  tobacco^moke.  It  is  very  stable,  being  unattaeked 
by  boiling  nitric  or  ehroniic  acid.  It  reacts  with  siilpbnrir  a*-id 
only  at  high  temperaturt?3,yieUlij)gasu)phonicaeid.  T|r-  halngens 
have  very  slight  action  on  it.  On  very  energetic  reduction  witlt 
hydriudic  acid  at  300°,  it  yields  normal  iM'nlani'  and  ammonia. 

Being  a  base,  It  yields  sails  with  aeiiis,  mostly  rea<Hiy  soluble  in 
water.  The  forrocj'anide  dissolves  with  dlfliciilly,  and  Is  employed 
in  its  purification.    With   platinum  chloride,  tbc  hydrocblorida 

488 


CONSTITUTION  OF  PYRiDINE. 


489 


yields  a  double  salt,  (C(ngN)^I,rtCl„  freely  soluble  in  WAtcr.  On 
boiling  this  solution,  two  molecules  of  hydrochloric  acid  are  clinii- 
naled.wilh  produptioii  of  a  yellow  compound,  (C4H(N),rtCI„whidi 
K  niily  slightly  H>]uljle  in  wat«r;  this  reaction  affords  &  delicate  test 
for  pyridine.  The  following  test  is  also  vpry  delicate.  On  warm- 
ing the  base  with  methyl  iodide,  an  enet^tic  reaction  takes  place. 
»nth  formation  of  an  addition-product,  CjHjN-ClIgl,  When  this 
is  warmed  with  solid  potash^  it  givca  ofT  &  vcr>*  pungent  and  dia- 
Sgrecable  CHluur. 

387.  Many  tnt-thods  for  the  synthesis  of  pyridine  and  its  homo- 
logufs  an;  known,  although  but  few  of  these  afford  in«ght  into  its 
constitution.  Among  them  is  the  formation  of  pyridine  from  quino- 
lioeaiid  [x-ntamotliyIenediaminc(182).  When  the  hydrochloride  of 
tho  latter  is  gubmitted  tu  dry  distillation,  piptridine,  or  hexahydro- 
pyridinp,  is  pniduced,  and  can  be  oxidized  to  pyridine  by  heating 
with  sulphuric  arid : 

H 
XH.CH.NHHJICI  XH.-CHj.  >CCH 

CHZ  |—  -»Cn<  >NH-.HC<     >N. 

^CH.-ClLiNH,  -Vn,-CH/  ^CCH 

Another  metho<l  of  preparing  pyridine,  which  is  carried  out  at 
low  temperatures  and.  therefore,  afftinls  even  more  t ruslwiirthy 
evidence  of  its  constitution,  is  from  '-chlomamylamine;  when  an 
aqueous  solution  of  this  substance  ie  healed  on  a  water-bath  for 
some  time,  it  is  transformin]  into  the  hydrochloride  of  piperidine: 


/nj  .^^H| — CH, — CI 


••ClilorMi  my  kuiiio 


'C".<ch;::?h;»^'«'Hci- 


f-Chloronmylnmin«»  wa«  thhs  obtained  by  GABRtet.  ^-Clilofo- 
propylphfnyl  tithcr,  obtriiDi-d  from  chloro  trim  ethylene  bromide  and 
eodiuin  phenoxide,  rvactu  thus  wit  It  sodioinaloolc  ester: 

C,H,0  CH,  Cn,CH,a  +  NaCH(COOC,Hj,  - 

-  C^iO-CH,-CH,CH,CH(COOC',H,),. 

On  saponilicatian  of  this  ester,  and  subsequent  heating  of  the  acid 
obtained,  ODS  molecule-  of  earhon  dioxide  is  epiit  off,  with  formation 
of  «-phei>oxy%-aleric  acid,  C4I(0'(CH^,.CO0H.    When  tJiis  acid 


•49° 


ORGANIC  CHEMISTRY. 


Is  liHt«d  vith  iMd  thioe]rftn«t«,  It  i«  conceited  into  tboeorrMpond- 
ing  Dttrile.  C»tIO-(CII,),.CS,  which  is  reduwd  by  BoJiiim  atwl 
alcohol  to  •-phenoxyam}'! amine.  C,HjO-(CH,),-NH,,  On  hoftting 
with  bydracliloric  acid,  the  phenoxyU group  Jn  ibii  amine  ix  replaced 
by  chlorine. 

Since  pyridine  is  coidly  redu'ccd  to  pipcridinc  by  sodium  aud 
olcliohol.  and  pip«ridiuc  can  be  oxidized  to  pjTidine,  it  may  be 
assumed  that  pyridine  has  tlic  s&me  clos«d  chain  as  piperidiae; 
that  Is,  one  of  five  C-atoius  and  one  N-atora.  Moreover,  iljcan  be 
proved  iliatthe  N-atom  in  pyridine  is  not  linked  to  hydrogen;  for, 
while  pipcridinc  I)08S«S3C3  the  cliaractcr  of  a  3econdar>'  amine,  yield- 
iiif.  a,  iiiiniso-derivativi;  for  example,  pyridine  hoe  tliat  of  a  tcrtiarj- 
amine;  thus,  it  yields  an  atIdition-product%\-ith  methyl  iodide  (386), 
ami  the  iodine  atom  in  this  substance,  like  that  in  other  an^monium 
iodides,  can  be  cxchan^d  for  hytiroxyl  by  means  of  moinl  silver 
oxide. 

The  number  of  iwjnieric  subetitutJon-products,  like  that  of 
benzene  (263),.  indicates  that  forh  rarhon,  atom  is  in  union  tcUh  one 
hydrogen  atom,     A  substance  of  tlie  formula 


should  yield  three  monosubstilution-prochMrts,  2  —  6(a),  3  =  5((S), 
and  i{y).  Moreover,  for  aimilar  dubetitueots,  eix  disubslitution- 
pHHlurUi  are  possible:  2:3-6:5;  3:4  -5:4;  2:4  -  6:4;  2  :6, 3:3, 
and  2:5  =  6:3.  Tliis  agrees  with  the  results  of  experiment.  The 
mode  of  linking  of  thno  oiit  of  the  four  valencio-s  of  each  carbon 
atom  is  thus  established,  and  that  of  two  of  the  three  nitrogen 
valencies;  it  rcmainK  only  tti  determine  how  the  f<nirth  valency  of 
each  carbon  atom  and  the  third  of  tiic  nitrogen  atom  are  distributed 
in  the  molecule. 

The  same  argumcat  wliieh  led  to  the  asauinplion  of  the  centric 
formula  f<ir  l>enzcne  (2M)  am  applicable  here.  The  great  stabihty 
of  pyridine  towards  energetic  chemical  reagents  proves  that  it  does 
not  possess  flnuble  bonds.  Further  atialngica  with  b<!n;(rne  support 
the  aaamnption  of  a  similar  comstitutJon.     Only  the  side-chains  of 


I 


PYRIDINE  ASD  ITS  HOMOLOGUES. 


4»l 


both  compounds  are  attacked  h}'  oxidising- agents;  nith  sulphuric 
ai'id,  both  jield  sulphonic  acids,  which  are  coiiverttd  by  fusion  with 
caustic  potash  into  hydtnxyKIcrivatives,  and  by  heating  with 
jjutassiuni  cyanide  into  cyaniilea.  The  hydroNyl-derivativcs  of 
pyridine  have  a  phenolic  cliaracter:  they  yield  characteristic  colour- 
ali'ins  with  ferric  chloride.  The  OMistiUitioQ  of  pyridine  must, 
then-fore,  bo 

CH 


'A 


bckS/CK 

N 

It  muil  be  lookfd  upon  at  benzene  in  wAkA  »ti«  of  th(  CH-grouj>s  nas 
been  rcplacfdbij'S. 

NotwithstaiidtiiR  these  nnnlogii^,  thfrc  are  great  differences  in 
tlio  l>ctinvi(Mir  nf  bcnienonnd  pyridine,  one  of  thorn  iwing  thnl  pyri- 
(litiL-  doi-s  not  udnilt  of  nitnition. 

The  principle  of  the  oriontatioii  «f  p>Ti(iiae  is  the  same  as  that 
f)f  b<'nzene — cimversioii  of  a  compound  t»f  iinknuwn  gtmi-tiin"  iiit<i 
one  with  its  sidt'-fhainK  in  knoivn  ptisitioiis.  The  nKinotiarbnxylic 
and  diipaxlxixylic  arids  have  acni'cd  as  the  mam  basis  for  its  orienta- 
tion: the  iiiclhod  of  o.srtTtuiiiin(i  llif  portions  ocrupii-d  by  the 
carboxyl-groupa  in  tht-ae  conipomuls  ip  described  in  890. 

Homoto^ufrB  of  Pyridlae. 
388.  The  honiologues  of  pyridine  are  the  methylpjiidines  or 
picolinee,  dimethyl  pyridines  or  hiiidinea,  ai.d  trimethylpyridincs 
or  caUidi.nf9.  Many  of  them  can  be  obtained  by  more  or  less  com- 
plex methods;  thus,  ^-picoline  is  formed  by  the  distillation  of 
acroleiR-ammunia  (M7),  and  eollidiue  by  the  JistiUation  of  eroton- 
aUlehydivaimiionia.  Tliw  furtnalioii  of  pyridine  and  its  homohiKiies 
by  the  drj'  distiltation  of  bones  depends  upon  these  reactions;  under 
the  influence  of  heat,  the  fat  present  yields  aL-roIein,  wlilcb  reacts 
with  the  annnonia  n-aulting  from  the  heating  of  the  albumins, 
forming  pyridine  buses. 

Hantskch  has  diaco^'ered  an  important  syntliesis  of  pyridine 
derivatives — the  condensation  nf  one  molecule  of  aldchyde-AJiamoua 
nith  tn'o  molecules  of  acetoacetic  eater: 


493 


OKGANIC  CHEMISTRY. 


CH,i 


K. 


o<!h 
c^,oocch,       ch,cooc^, 

ch,.co        coch, 

HNB. 
CH, 

aH.oocc^      ^CCOOC,H, 

II  +  3H,0. 

,CCH, 

H 
I>Ili]n]nwi>llidlne<lk«rlKnqtllc  Mt«r 

On  oxidation  Willi  iiitmiitt  ni^id,  tSiiii  .>(ubstAnce  loses  two  Tl- 

onv  from  the  CH-Kn)U|i  hikI  orn-  from  Ww  NH-group,  with  foiDHh ' 

lion  of  eollkiiiu'dK'urlKixylii^  clliyl  t'stcr.     On  capon  i  fie  at  ion  of  Mm 

wtlh  caiutic  tmbu;<h,  and  HubsiM|ucnt  hi-jititig  of  the  potusaium  salt 

with  quickliniv,  tJi<!  carboxyl-groups  ure  B|)lit  off,  and  coUidinej 

a 

distils  over. 

In  lliia  sj*Ti(hp*ii»  lUTtAlilntiyde  may  be  n>plaecd  by  other 

hydfe.and  aci-toauctJL'  i-wttT  l)y  the  vstnTs  of  ctthrr  ;3-ketonic  &cid>  i. 

that  it  affords  a  nH'tiKxl  of  prc|>!tririg  iiuiiutuu»  pyridine  dcrivnlivw. 

Some  of  the  honiologULW  of  jjyridine  can  lie  oblaineil  from  it  bv 

the  action  of  an  alkji  iodido,  an  ailditioti-proUuct  Ixrinjir  formed 

On  Iitatiiig  this  to  300°,  the  alkyl-group  becomes  detached  from 

the  nitrogen  atom  ami  links  itself  to  a  carbtm    atom    a  n-action 

fcuuluiious  lo  the  forniation  of  tuluidiiie  by  hi^athig  luethylaiiiline 

hytlrochloride  to  a  high  t-cmperaturc  {285) . 

a-AUylpyridinr  »  of  tiieurptical  imporUincc.      Laden-duro  et 
tained  it  by  the  mndeiisaticm  of  a-picoUne  with  acetaldehj-de  • 

NOU,  CH,  +  OCHCH,  =  NC^H.-CH:  Cll-CH    +  HO 
By  iU  Hid  he  effected  the  first  synthesis  of  a  natural  alkaloid,  that  A 
coniiiw'.C,H„N(40S).     «.AllyIpyrKhno  was  reduced  with  sodii-' 
and  boiling  alcohol,  yielding  "-pnjpj/pipcrid-iTi* 

H  ' 

NH 


DERiyATiUBS  OF  PYRIDINE. 


49S 


whicli  dUTcra  only  from  aatural  coruTae  in  being  opiirally  inactlTe^ 
whereas  ihc  alkaloid  is  optimally  active.  Tliis  sulislanc-c  was  re-- 
solved  into  a  dPXtro-rotator>'  and  a  In-vo-nrtBlory  miKlificatJon  by 
fractional  frystallizfttioTi  of  its  tartralc.  the  dcxtro-rotalory  isomer 
pniviiig  Ui  lit*  identical  with  natural  coniine. 

TTie  conslitutionBl  formula  of  this  eompouml  indicates  that  tlie 
carlwn  atom  in  iinimi  with  Ihp  propyl-gmiip  is  awmnieiric.  ,^-Pn>- 
pylpiperidinc  and  >'-propylpiprridinc  do  not  contain  an  aH>'mmetri(? 
carbon  atom,  ard  should  tlirifforc  \k  optically  inactive,  which  is  a 
proof  of  the  'f-stnicture  of  coLiine,  as  well  as  of  picoline,  from  which 
lit  is  deriv<-d.  A  further  proof  i«  tlwt  coniTin?  KpUUi  up  into  animonia 
d  normal  oetaiio  when  strongly  heated  with  liydrioilie  aeid. 
us  treated,  a  ^-propyl pi jjeridiiie  or  ^--propylpiperidine  luust 
yield  an  octane  with  a  branched  side-chain. 

Pipcriditif  15  |)rcscnt  in  pcppiT  in  combination  as  piperine, 
C,,H„NO,;  on  bailing;  with  alkaJii^,  it  yields  piperie  add,  C„H|„0«, 
and  pi|ipridiiir,  liy  addition  nf  one  innlcnilc  of  water.  Pipcrine 
miixt,  thi'H'lorp,  ho  looked  upon  as  a  substituted  lunidf^  of  pipcric 
aeid,  fontaiuiiig  the  piixiridine-reiiidiip,  C\H,(N — ,  inxtcod  of  tlie 
NKf^roup: 

(yi,^'-C„H,0.. 

Piperjdine  is  a  eoluurktis  liquid,  boiling  at  106",  with  a  charac- 
teristic |top]xT-likn  ndnur  and  strnnply  marked  baaic  pnipcrtica.  It 
ia  beet  obtained  by  tiie  electro-reduction  of  pyridine. 


FyrlduieQarboxylia  Acids. 
389.  Three  pyriditwmojwcarboxyiic  acids  are  known : 


0 


COOH 
N 

nci>lliiic  ftdd  M 


f^^COOH 
N 

KlooUiklc  •«»<#) 


COOH 


0 


N 

iKmlcollok  *cld  if) 


The  orientation  of  the  carboxyl-Eroups  in  these  acida  can  be  carriccl 
out  as  follows.  It  was  stated  in  388  that  the  side-chain  in  coniine 
occupies  tlie  ff-position.  ')ii  oxidation,  this  sulistanec  yields  picol- 
{iiic  acid,  by  conversion  of  the  propyl-group  into  a  carlxixyl-groiip, 
and  elimination  of  the  six  added  hydrogen  atoms.  Kcolinic  acid 
is  therefore  the  n-carlwxylic  acid. 


494 


ORGANIC  CHEMISTRY. 


Niroiiiiic  ncid  is  proved  ia  have  the  ^-constiLutioo  thus:  quino- 
Imc  (395)  ha«  the  formulii 


It  is  naphthalene  in  which  onr  of  tlic  rt-^II-Rrniips  lias  hrcn  replaced 
by  N.  On  oxidation,  quinoliiic  yields  a  pj-ridircdicarbosylic  acid, 
quiwAinic  acid,  wliich  must  therefore  have  the  structure 

fiCOOH 
•^'COOH 


On  heating  this  acid,  one  moletule  of  oarbon  dioxide  '»  eliminatM. 
with  fommtioii  of  nicotinic  arid.     Since  the   carboxyUgroup  in 
piailinic  ai-iil  lias  been  proved  to  occupy  the  *r-posiiion,  nicotinic 
acid  must  be  tiic  /9-acid;  there  remains  only  the  y-etructure  tor 
isonicotinie  iipid. 

The  pyridincnionocftrboxvlir  arids  are  formed  by  the  oxi^lation 
of  the  homologues  of  pyriilinp  conlmning  a  side-chain.      Nicotinic 
arid  derives  its  name  frnin  ius  funriatuut  by  ihc  oxidation  of  nicotine. 
The  mnnocarlinxylic  aridH  art-  i-rj-filidlinn,  and    possess  both  a  basic 
and  an  acidie  characlcr.     As  bases,  they  yield  salt.s  with  acids  and 
double  salts  with  platinum  ohioride  and  mercuric    chloride    etc  ■ 
As  acids,  ihey  fomi  salts  with  bases,  the  copper  salts  bcine  oftoi 
employed  in  their  seporntion. 

Picolinic  aeid  can  be  dist Inguiahed  frona  its    isomers  bv   tw 
prupertiea:  on  heating,  it  splits  off  CO,  more  rea^Hly  than  they  d 
with  formation  of  pyridine ;  and  it  gives  a  ycllowjsh-red  colouration 
with  ferrous  sidphate.    Quinolinic  aeid  ans^vcra  to  tho  Rame  t 
it  may,  thereforf,  be  conclude*!  that  they  are   apiilicablo  -to       '■    ^ 
with  a  carboxyl-group  in  the  flr-iJojdLion. 


1 


TOO.  By  Itie  aid  of  thesy  reactions  it  is  possible  to  dptorminr  t'hii 
positions  of  the  carboxyl-KroUTw  in  the  six  PUritiinedicarhoxuliJ 
On  hpatinp  with  Rlneial  arotic  ncid,  dipicolinic   arid  B\A'tK     « 
tnoleculu  of  CO,,  funiiirig  picoliDic  acid;  on   healine   al  -     ' 


PYRIDINECARBOXYUC  ACIDS-  495 

two  molecules  of  CO],  yielding  pyridine.    It  must,  therefore,  have 
the  aH'-structure 


HOOc'v^COOH  • 


N 

Quinolinic  acid  was  proved  in  8S9  to  have  the  "^structure.  LuHd- 
inic  acid  answers  to  the  ferrous  sulphate  test,  and,  on  heating, 
readily  loses  one  molecule  of  CO,,  forming  isoQicotioic  acid;  this 
proves  it  to  be  an  a7-coinpound, 

COOH 

.'COOH ' 

N 


Isocinchomeronic  acid  also  gives  the  colouration  with  ferrous  sul- 
phate, and  is  converted  by  heat  into  nicotinic  acid.  It  cannot  be 
the  a^-oompound,  this  structure  having  been  proved  to  be  that  of 
quinolinic  acid,  and  must,  therefore,  have  the  ajS'-constitution, 

HOOC,^ 

l^COOH- 

N 

The  positions  of  the  side-chains  in  four  of  the  six  possible  isomers 
have  thus  been  established.  For  the  two  other  acids  there  remain 
the  structures  pp"  and  fiy, 

COOH 
HOOC/NCOOH     ^^j      j^COOH. 

N  N 

When  strongly  heated,  cinchomeronic  acid  yields  isonicotinic  acid 
along  with  a  small  proportion  of  nicotinic  acid;  under  similar  condi- 
tions dinicolinic  acid  yields  only  nicotinic  acid.  They  cannot  be 
B-compounds,  for  they  do  not  give  the  colouration  with  ferrous  sul- 
phate; it  may,  therefore,  be  concluded  that  cinchomeronic  acid  has 
the  ^-structure,  and  dinicotinic  acid  the  pp*  structure. 

391.  Pyridine  may  be  looked  upon  as  derived  from  benzene  by 
replacement  of  one  CH-group  by  N.  Other  closed-chain  com- 
pounds are  known,  derived  from  benzene  by  replacement  of  two 
CH-groups  by  O,  N,  or  S,  respectively.  Such  are  furfuran,  C4H4O; 
pyrrole,  C,HjN;  and  thiophen,  C,H,S. 


49* 


ORGANIC  CHEMISTRY. 


n.   FTOroBis,  c,»,o. 

Furfuran,  B.P.  36",  is  itsolf  of  liitle  importance;    two  of  its 
sub8titutiun-produ(.-l«>  must  be  cnnsidi^red  in  some  detail. 
To  furfuran  is  assigoeil  the  ring-formula 

HC — CH 


Hi!     h. 


V 

This  is  supported  by  tHp  resemhlancp  in  properties  between  somo 
of  its  derivalives,  such  as  juTJtimliiehjde  (furfural  or  furjUTole), 

C,HjO'Cf:,aiid  the  correspond! nji  iM^nzene  derivatives.     Moreover, 

the  O-atom  can  l>r  pmvc*!  to  Im-  linkt^d  similarly  to  tliat  of  ethylene 
oxitlt  (ISei,  sinn-  nn  trcatmrnt  with  soLliuiii.  hydrogen  is  not 
evolved  fmm  furfuran,  which  pmvps  (he  absence  of  a  hydroxyl- 
group:  and  stiipc  it  is  not  acted  on  by  hydroxylamine  or  phenyl- 
hydrazine,  which  indicates  that  it  does  not  contain  a  e&rbonyl- 
gnmp. 

Furfuran  derivatives  can  bo  obtained  from  thi?  1  :-l-dikctones, 
K-CO-CHj-CHj-COR,  by  trealownit  with  dehydratinji- agents, 
Buch  as  acetyl  chloride.  This  reaclifni  may  be  looked  upon  as  the 
nwilt  of  the  t-otiverslon  of  the  dikclnnc  into  on  unstable  form« 
R-C;CHCH:C- R,  which  then  splUa  off  water; 

OH  OH 


"r<oiH 


-  H,0    - 


HC=:C/^ 

Hc=c<;  ' 

^R 


Tlufl  method  yields  ^rt'-substituted  furfuran  derivatives,  the  6- 
atonis  ID  furfuran  being  denoted  a?  in  the  scheme 


V 


M 


FURFURALDEHYDE.  497 

This  syntfaeds  of  furfuran  derivatives  is  likewise  a  proof  of  their 
constitution. 

The  meet  important  derivatives  of  furfuran  are  furfvraldehyde, 

C4H,0-Cq,  and  pyromucic  acid,  C4H,0-C0OH,  both  of  which  have 

long  been  known. 

Furfuraldehyde  is  prepared  from  pentoses  by  the  method  men- 
tioned in  211.  It  has  the  character  of  an  aromatic  aldehyde;  like 
benzaldehyde  (299),  it  is  converted  by  alcoholic  potash  into  the 
corresponding  acid,  pyromucic  acid,  and  the  corresponding  alcohol, 
fwfuryl  alcohol,  C^HjO  •  CH,OH : 


l^COOH     ■**     IJcHjOH. 
O  O 

FortimldehTde  Pjromuolo  mcU  Piuturyl  aloohol 


With  ammonia  it  yields  furfuramide,  (CjH^OjNj,  analogous  in 
composition  to  hydrobenzamide  (299).  Just  as  benzaldehyde  con- 
denses in  presence  of  potassium  cyanide  to  benzoin  (368),  furfur- 
aldehyde under  the  same  conditions  yields  the  similarly  constituted 

H 
jvTOln,  C^HjO-C-CO-C^HjO.     The  resemblance  in  properties  be- 

OH 
tween  the  two  compounds  is,  therefore,  very  striking. 

Furfuraldehyde  is  proved  to  have  the  ar-structure  l^  varoua 
means;  for  example,  by  its  formation  from  pentoses  (211),  which 
may  be  represented  thus ; 


HO      H 


(^-CHOlH  CH=^^ 


CH-C^ 


OH  CR 


HO     H 


PmiIom  Parfimtdehyda 


Furfuraldehyde  results  from  the  elimination  of  three  molecules  of 
water  under  the  influence  of  hydrochloric  or  sulphuric  acid.    It  is 


■*98 


ORGANIC  CHBMiSTRY. 


a  colourless,  oily  liquid  of  ogrcciiblc  odour,  and  boils  at  162°.    A 
\vi3t  for  it  is  described  in  211. 

Ah  its  nainp  indicatos,  pyromucic  acid  is  fonncd  by  the  dry 
dlstUlatUm  uf  mutic  acid  (812,  6).  It  can  abo  be  obtained  by 
oxidiaing  furfuraldeliyde  with  flttver  oxide.  It  m  crystalline,  niclta 
ut  i;i*2*,  can  be  readily  sublimed,  and  dissolves  freely  in  hot  water. 
W  lien  heated  at  275°  in  a  sealed  tube,  it  splits  up  into  carbon  dioxide 
and  fiirfnran. 

r'yniiinieie  neid  wholly  \zc\%  the  charaeter  of  an  arriniatic  com- 
pound :  its  pru]KTties  in  no  way  ri^sfinbk*  those  of  l)eiiz(jic  acid,  but 
are  like  those  of  the  un.saturat«l  fatty  acids.  Thus,  it  eaadly  under- 
gors  oxidation;  it  almost  instacitaaLi»u«ly  dcctilourizea  Baeyeb'S 
reaKviit  (123),  and  readily  odds  four  bromine  atoms.  Hence,  the 
distinguishing  characteristics  of  the  ber zone- nucleus  are  absent,  so 
that  the  formula 

HC=CH 

I       >o. 

HC=C 

COOH 

with  two  double  bonds,  must  be  assipned  to  it. 


'  m.   FTBBOLE.  C.IItN. 

3'92.  pyrrole  is  present  in  coal-tar,  and  in  "  Wppel's  oU  "  (388), 
It  is  a  colourless  liquid  of  chloroform-like  odour,  and  boils  at  131*. 
The  vapou"^  of  pjirole  and  Us  ilerivatives  impart  a  carmine-red 
colouration  to  a  wood-shaving  iiioi.st('npd  with  hydrochloric  acid, 
due  to  the  formation  of  an  amorphous  substance,  pyrroic-red. 
This  is  a  delicate  test  for  these  compounds. 

Pyrrok*  can  be  aynthesizt'd  by  distilling  succinimide  (169)  with 
ziHc-dust,  wliieh  proves  its  constitution: 


j—CiY 

Suocioliii'i]'* 


L 


CH--cn 

I  >NH. 

CH=CH 
Pyrroto 


Pyrrole  derivativea  are  obtained  from  l:4-dikctones  by  t]-eat>- 
ment  with  ammonium  acetate,  a  process  analogou.s  to  the  formation 
of  furfuran  dt^rivatives  from  these  substaiuips  (3dl): 


PYRROLE  MKD  TMOPUEN. 


499 


^f=*\[0H7H 


H 


M'Pyrrolft 


l:4-blkDiuM 


Pyrrole  has  to  some  extent  the  charactw  of  a  secnndary  amine. 
The  hy<lri»p'n  linkfii  U>  uitroKt'ti  can  be  replaced  hy  [Kitas.viiini,  wilh 
frimmtmii  of  poiassio-pyrrole,  C\H(?JK.  which  n-afta  with  B.lkyl 
Iiolidcs,  ockl  chloriJea,  etc.,  yicMiitg  "N-subslHutior-proJiicta;" 
that  IB,  pyiTftle  derivatives  with  siikstitiicntii  in  union  with  the 
N-fttnin. 

Pyrrole  resemblpR  lienReiie  in  properlips  munh  mom  clnsdy  than 
furfuraii  tlors,  h<^ing  much  mnrr  wtnWe  than  the  latter.  As  a  result 
of  this,  it  cliH-s  iiut  yifUl  lulilitioii-prodiicls  wiili  halogens.  On 
rciluctioii  with  ziiic-iJu»t  aiiJ  awlic  aciii,  htmrvi-r,  it  tuke£  up  two 
hydrogen  atoms,  with  foniiation  of  dikyelropyrrofc*  or  pifrroline, 
CjHaNII,  which  adds  on  two  atonLs  of  bromine.  This  behaviour 
is  ver>'  like  that  of  benzene  and  its  partial Iy-liydrat<?d  derivatives 
(870),  For  these  and  other  reastjns.  pyrrole  is  assumed  to 
centric  bonds,  aad  its  formula  l^ccomea 


IV.  THioPHEK,  c,n,a. 

393.  Thiophen  has  the  itioat  aromatic  character  of  the  com- 
poundtt  inentioncfi  at  the  bugiiiiutig  of  591. 

It  i.4  present  in  the  crude  benzene  obtained  from  coal-tar  (267) 
to  the  extent  of  about  0-5  per  cent.;  if-s  honiologues,  thiololen  or 
methylthiophen,and  thioxm  tir  tliinethylthiophcn,  are  contained,  in 
tolnene  and  xylene  from  the  some  source. 

"Tbo  CnK»iCAL  Socirrv  or  Londoh  cmptnys  tlir  nuue  dih^/dnprmU 
fortLe  cam)ioun(l  C.n,N,  atul  Utrahi/dropprroU  for  C,H,N.  tn  lli»  nomeneU- 
lura  of  (h«  (J  situ.tN  CsBWiCAL  SociBTT  tlji.-  ccTrotpnadiDg  toruB  ftr<  pgrrotiH 
uih]  pt/rrolidiii. — TrahalatiML 


joo 


ORGANIC  CHEMISTRY. 


Thiophcn  WM  first  obtained  by  Victor  Meyer  by  agitating 
eoal-tar  benzene  with  anmll  amounts  of  concentrated  sulphuric 
acid  till  it  c<'a»xl  t/i  give  the  indo-phimin  rtiietitm,  a  blue  eolouratiun 
with  isatin  (398)  and  concentrate<l  sulphurie  acid.  By  tluH  tr^aU 
roent  the  ihiopben  is  converted  into  a  sulphouic  acid,  from  wbich  it 
can  be  r^ciicrated  by  tlie  a<'tioii  of  suix-Tlicatt-d  stcain. 

Thicipheu  can  be  ajnilheeized  by   vurioua  innthod^,  the  most 
iporUuit  bdjig  the  interaction  of  auccinic  acid  and  pentasulphide 
'•flC  phosphorus.    On  heatinfi  a  mixture  of  tiiesc  substances,  a  vlgw- 
4]Ud  reaction  enaite^,  carbon  di.siilphide  is  evolved,  and  a  liquid,  eao- 1 
sisting  chiefly  of  thiophen,  distiU  over. 

It  is  fl  enlourlesfi  liqni<i.  boiling  at  84",  a  temperature  which' 
differs  little  from  the  boiliug-pnint  of  benzene  (80-4*).     It,  lias  S 
funt,   non-characteristic  odour.    It  is  heavier  than  water,  its 
•pedfic  gra\ily  being  1-062  at  23°. 

Bromine    reacU)    eMergetically  with    thiophcn,  forming  ehicSy 
dibromoihiajtiu-n,  C^HgBrjS,  along  with  a  small  proportion  of  tha' 
monobronwMlmv  alive. 

The  lumiologina  of  tiiiophen  can  be  obtained  by  Fimo's  syiw ' 
thi'.sijt  (268)  and  by  other  melhods;  for  inatance,  by  hcuting  1:4- 
diketoiire  with  pentaxulphide  of  phosphonia,  a  mode  of  synthesis 
which  proves  the  constitution  of  the  tluophcu  bomologuea.    ThuSi , 
acetonylacctone  yields  dimelfiytthwphen  : 


KCH, 
OH 
I         •OH 
HC=C< 

\CH, 

(unatsulp  funn) 


^ClI, 

u'-noMttirlUiicftbni 


Since,  however,  thinphen  has  all  the  protw-rties  of  an  aromatic  com- 
pound, it  mu.st  also  \m  BKiuine<i  to  posst-sa  centric,  and  not  double^ 
bonds,  «o  that  it-s  constitution  i»i  represented  by  the  following  scbema 
whicli  also  shows  the  mode  of  denoting  the  carbon  atoms 


V' 


THIOPHBM. 


501 


ofl'-Dittlkyl-thiophens  arc  obtaiued  from  l:4-diketone8;  the 
/J-alkyl-coinpoimris  cAn  be  jireparwl  bj'  auotlier  niethixl.  It  was 
etati^i  (p.  500)  that  thioplien  results  from  the  interaction  of  suc- 
cinic acid  and  pciilasulpliitlc  of  phosphorus; 


H,C— OOOH 

nij-oooH 

BihcIbIohU 


H 


HC-Cv 

HC-C^ 
H 

Thloptteo 


■Rimilarly,  a  m<moalky)-siiccinic  and  symmptrical  dialfcyl-succinic 
acid  reapcctivdy  yiu-ld  a^-alkyl-thmphen  and  ft/?;?'-aIkyl-thiophcn: 


CH,CH-COOH 

crr,-cn-cooH 

BjrmiriaiTlwl  dlniaih;]. 
•uoclnlo  •dd 


CH,C-CH 

I      >S. 
CH,-^'-€H 

llilLip'bBn 


Tho  known  strueturp  of  tliost-  coinpouiuU  pan  Iw  cmploypd  ns 
a  basis  for  the  orientatioii  uf  \\w  derivatives  of  tliiophen. 

The  two  monocarboxylic  acids,  U'thiopliencarboxylic  acid  and 
fi'thiophencarhoxylic  acid, 


\JfX>Oll    and 


iCOOH 


poseffs  the  remarkable  property,  when  a  cold  aqueous  solution  con- 
taining both  of  them  is  crystalliited  slowly,  of  forming  a  mixture 
which  caiinot  hv  rosolvefl  into  its  cmnponcnt^.  On  oxidiiiiip  a 
mixture  of  n-lhiotolen  and  .J?-thiotolen,  an  apparmtly  honioge- 
tieous  acid  is  obtained:  from  its  method  of  formation,  however,  it 
can  only  be  a  mixture  of  the  cnrreKpfmdinE  arids, 

Thiophmketonex  am  prepared  by  Friekel  antl  Crafts'  reaction 
(288) ;  thus,  acetothienonc  or  a-thiinyilmefhylkctonf.  C,H^-COCH, 
is  obtained  frmn  aec?ty!  chloride  thiophen.  ami  aluminium  chloride. 
These  kptones  are  reatlily  oxidijtt^d  to  ihiopbenearboxylic  acids, 
a  good  method  nf  preparing  these  compounds. 

A  thiophmaulphonic  acid  is  also  known;  it  is  more  easily  fonned 


50J 


ORGANIC  CHEMISTRY. 


thajt  berizpiieeulphonic  acid,  u'tiich  funiish^  a  methtxl  of  popoTAlinf; 

tliiophpii  and  txfiizene  (p.  500).    On  (liatillation  with  potassiuni 

cyaiinlp,  it  foniw  the  coirtspciiiding  nitrilc;  but  XW  siiJphogmup 

is  not  rxclianji^cil  f(ir  hydroxyl  by  fuHion  with  caiiMic  potasti.     It  is 

possible,  however,  to  obtain  a  tfiiopiicnpftcnoi  by  the  ioteracUon  of 

aminothiophen  hydrochloride  and  aitrDiu'itcid,  which,  yields  a 

NO 
nitrated  hydroxyl-dcrivative,  C4HjS<Qtj*.  This  compound  greatly 

nfcmbles  p-nitrophenol;  thus,  it  dissolves  in  alkalis,  yielding  a 
solution  of  yeliDw  colour. 

On  vulatilizliig  (hiophen  in  a  curmit  of  air,  and  passing  the 
rpsidtin)»  gajwmus  mixture  into  carefully  cociled,  fuming  nitric  acid, 
the  principal  product  Is  dinilrotltwjyfifn,  altliough  nufnonilrolhiophen 
is  also  fomicd.  The  tatter  U  a  solid,  meJttng  at  44°,  and  boiling  at 
224**;  it  haa  au  odoiir  like  llinl  of  nitrobenzene.  On  redurlion,  it 
yields  aminothiaphcn,  or  tMophtnine,  wliich  differs  from  aniline  in 
being  very  (instable;  it  qiiiekly  ehangi?8  to  a  varnish-like  mass,  but 
its  hydrticliloridf  is  .stable-.  It  does  not  yield  diazo-oonipounds, 
but  rwiPta  with  benzentdianonimn  elilori<le,  fonning  a  crystalline, 
orange  dye. 

Many  other  ttiiopKen  derivatives  have  been  obtained.  chtrBy 
through  the  researches  of  ViCTon  Meyer.  The  examples  which 
have  been  cite<l  siitfioe  to  indicate  the  great  analogy  subasiing 
betn^een  the  propertien  nf  thioplien  and  those  of  benzene. 


7.     PTBA20LE.    C,H,N,. 

894.  Pyrarolr  is  obtained  by  the  action  of  hydrazine,  NH,-NH» 
on  eiMchlorhydriu  (l^SSj ; 


CHj— CH 

iCll 


H,N-NH|H 


CH— CH 

II        II 
N       CH. 


Hydrr^n  is  simultaneously  eliminated,  which  Is  effected  by 
ploying  excess  of  hydrazine;  one  molecule  of  this  takes  up  *\ 
atoms  of  hydrogen,  forming  two  molecules  of  ammonia.    This  syo- 
thesis  proves  that  pyrnznle  has  the  above  formula,  so  that  it  n)ay  bo 


PYRAZOLE. 


503 


regarded  as  pyrrole  in  whieh  one  of  the  CH-groupe  dm  been 

roplseod  by  N. 

It  is  crystalline,  melts  at  70*,  aiul  is  very  stable.  It  yields 
only  a  weak  base,  for  its  aqwous  solution  has  a  neutral  reaction. 

Pyrazole  itself  does  not  give  impoiiajit  derivatives,  but  such 
arc  obtained  from  a  dihydm-prmkict,  ptfrazcAinc,  C,H,N',.  formed 
by  the  action  of  hydrazine  hydrate  on  acrolein.  This  subetaace  has 
the  formula 

CH— CH, 

Yh 

Bromine  converts  it  into  pyrazolc.    A  ketonic  derivative  of  f^Taxo- 
line  its  called  pyratoUme,  anti  has  the  fnnauia 


CH— CHj 
N      COj 

XH 


Bubslitution-productfl  of  it  arc  obtained  by  the  interaction  of  accto- 
acetic  ester  and  phonylhydraEinc: 


CH,— CO 

H,C 


+ 


jyN 


:-C0  •  |OC,H,       H|yC,H, 


CH,-C=N 

I  >N.G,H». 

H^C-CCK 


MfihylplitTiylpiiriuoItme  is  thus  formed.  Methylpheiiylbydrazine, 
C,lIs-Nir'NH-('Hs.  eondcasL-a  similarly  with  acetoacetic  ceter, 
yielding  a  diinethylplieuylpyrazolone  with  the  fonaula 

CHjC-NCCH,) 

This  is  anlipjirine,  C„TT|,,N,n.  which  was  discovered  by  Knobr, 
and  is  extensively  employed  in  nii-dicinc  as  a  febrifuBc.  It  ciys- 
tallizw  in  white  leaflets  melting  at  113'';  it  cannot  be  distilled 
without  undergoing  decompnfltioa.    It  is  readily  soluble  in  water 


504  ORGANIC  CHEMISTRY. 

and  alcohol;  the  aqueous  solution  g^ves  a  red  colouration  with 
ferric  chloride,  and  a  bluish-green  one  with  nitrous  acid. 

Antipyrine  is  manufactured  by  condensing  pheoylhydrazine  and 
acetoacetic  ester  to  methylpheDylpyrazoloiie,  and  subeequeotiy 
introducing  a  methyl-group  into  this  compound  by  heating  it  with 
a  mixture  of  methyl  alcohol,  methyl  iodide,  and  caustic  potash. 

Many  other  ring-compounds  are  known,  conttuning  rings  of  six, 
as  well  as  of  five  atoms,  but  these  an  beycmd  the  scope  of 
this  book. 


CONDENSATIOV-PBODUCTS   OF  BENZEHE  ASS 
HETEROCYCLIC   HDCLEI. 

395.  Only  three  of  the  compounds  of  this  class  ■n-ill  be  described: 
^tno^in^,  isoquinoline,  nnd  indole.  The  first  two  are  relat-ed  to  the 
alkaloid^,  and  the  last  is  important  on  account  of  its  relation  to 
indigo. 

I.  QDIHeLIIIE.  C.HfN. 

Quinnline  is  present  in  c-tial-lar  and  btine-oil,  but  it  is  difficult 
to  nbtiiin  it  pure  from  tliese  sources,  Jt  is  usually  prepared  by 
Skiuui-'s  sjTilhesis,  which  is  describfd  below.  It  is  a  colourless, 
hiphly  refractive  liquid  uf  cliaroeteristic  odour;  it  boils  at  236*, 
and  lias  a  specific  gravity  of  1  ■  U)S1  oi  0°.  It  has  the  eharacter  of 
a  tertiary  ha.se,  so  that  it  possesses  no  hydrogen  linked  to  nitrogen. 
It  yields  sall-s  wilh  arids;  the  dichromate,  (C,H,N),HjCrjO,,  dis- 
»o]ves  i,\ith  fliffieuHy  in  water. 

Qiiinoline  can  be  s>T»the.'*ized  by  various  methods  which  prove 
its  constitution.  Its  synthesis  was  first  effect*'*!  by  KoNics,  by 
passing  allylaniline-vapour  over  red-hot  oxide  of  lead: 


H    CH, 

H/^H\CH 


H      H 

h/\/\h 


W-*"°-  "W" 


+  2H,0. 


AllrknIIlM 


Skraup's  synthesis  consists  in  Iiealinjc  together  aniline,  glyc- 
erol, sulphuric  acid,  and  nilro benzene.  In  presence  of  sulphuric 
acid  as  a  dcliydrating-agent,  the  glycerol  lusts  water,  forming 
acrolein,  whieh  unites  with  the  aniline  to  acrolein-anilinc, 
C,Hj-N:CH'CH:CH,.  In  Koxigs' synthesis  the  oxidizing-agent 
is  the  lead  oxide;  in  this  it  is  the  nitrobenzene,  which  ia  reduced 
to  aniline.     Arsenic  acid  can  be  substituted  for  nitrobenzene. 

505 


50  6 


ORGMMC  CHEMISTRY. 


Babyer  and  Drewsen  ha^■e  discovered  another  method  of  sjm-- 
thctiis  which  proves  the  constitution  of  quiiioHine;  it  cuiuii^ts  in  tho 
reduction  of  o-nitrocimiamttldehydp.  Tliiw  is  firet  converted  into 
an  itilt'nnediatc  produft,  the  corresponding  amino-coni pound,  the 
H-at<)nis  of  the  NH,-groijp  of  this  substaiica  being  subsequently 
dimioated  along  with  the  0-atom  of  the  aldehyde-group : 


R     CH 


H 

H' 


H      NiH,    I 

O'Am  lDDcUniDtiuldehril« 


H     H 

s(X)" 

H     N 


The  last  RynthpBis  proves  quinnline  to  be  an  ortAo-subetitutod 
bennene;  the  cnnstitiilinn  <if  thj:  ring  coiitaiTiing  the  N-atom  has 
now  to  be  dctirniincd.  This  is  ofTected  by  oxidatloa,  which  pro- 
duces a  diba»c  add,  quinolinic  acid, 

H 

hooc/\h 

HOOcL  Jh' 


V' 


which  on  distillation  with  quicklime  yields  p>*ridine.  From  these 
facts  it  must  be  conchided  that  cininoliiie  contains  a  benzene- 
iiueleus  and  a  pyridine-nucleus,  witli  two  or(Ao-C-atom3  commnn 
to  both.  It  may  be  regarded  as  naphthalene,  in  whitJi  one  of  the 
a-CW'HTmtps  ktjs  hem  rrpfncfd  by  N,  It  was  mentionwl  (S63, 
370,  ond  387)  tliat  the  assumption  of  centric  bondt  w  the  most 
probable  explanation  of  the  structure  of  benzene,  naphtluilciic,  and 
pyridine.  The  analogy  between  these  substances  and  quinolinc  la  an 
indication  that  it,  too,  possefises  centric  bondSf  so  that  it  has 
the  formula 


i<IXI>i. 


ORIENTATION  OF  Qt^lNOUNE  DERiyATlFES.  S"? 

The  number  of  isomeric  substitution-products  is  very  large. 
The  seven  hydrogen  atoms  occupy  dissimilar  positions  relative  to 
the  nitrogen  atom,  so  that  seven  monosubstitution-products  are 
possible.  Twenty-one  disubstitution-producta  are  possible  for 
similar  substituents,  while  the  number  of  triderivatives  possible  is 
much  greater,  etc. 

396.  There  are  three  methods  for  the  orientation  of  quinoliue 
derivatives. 

First,  the  relative  method  (362, 1). 

Second,  oxidation.  This  usually  removes  the  benzene-nucleus, 
leaving  the  pyridine-nucleus  intact,  and  thus  furnishes  a  means  of 
determining  which  substituents  are  present  in  each  of  these. 

Third,  Skraup's  synthesis — an  important  aid  to  orientation. 
It  can  be  carried  out  not  only  with  aniline,  but  with  many  of  its 
substitution-products,  such  as  homologues  of  aniline,  nitranilines, 
aminophenols,  and  other  derivatives.  The  quinoline  compounds 
thus  obtained  have  their  substituents  in  the  benzene-nucleus. 
But  this  synthesis  also  indicates. the  positions  of  the  side-chains 
when  an  ortAo-substituted  or  a  para-substituted  aniline  is  used;  thus, 

/ 
can  only  yield 


X     NH,  X      N 

OrQia 


and     ^(\  only     ^QQ^ 

IH,  N 

Fara 


X  X 

while  1       I    can  yield 

NH, 
Mtta 

All  four  possible  quinoline  derivatives  with  substituents  in  the 
benzene-nucleus  can,  therefore,  be  prepared  by  Skraup's  synthesis. 


5o8 


ORGANIC  CHEMISTRY. 


Tlio  nomoriclature  of  the  quiaoliiic  derivatives  Is  indicatetl  in 
the  scbeine 


Many  of  the  Icnnw'Ti  qiiinriline  derivalivps  arc  obtainetl  by 
Skhaup's  mcthixl,  a  unmllrr  niiinltf'r  diret'llj'  from  qiiiiuiIinR.  The 
Rulphonip  acids  arr  Iipsi  prppurpd  by  th*  latter  metliod.  On  fusion 
with  caustic  pnliu^h,  tht-y  arc  mnvcrird  into  hydrnxyquincilim-s; 
when  Iieatt-d  witli  iwitassium  cyanidr,  thry  yield  cyan<H]iiinolincs, 
which  oil  hydrolysis  pivr  rarb«ixyhp  ucide. 

CariiosUjril  is  2-hydroxyqiiinolinc;  it  ean  bo  synthesiMd  by  the 
eliniinatiou  of  v>'&t4>r  front  o-aminocinnamic  acid: 


IH^COH 

It  has  a  phenoiic  character;  thus,  it  dissolves  in  alkalis,  aiid  is 
reprecipitated  by  CX\ 

n.    ISOQUmOLIHE.  C,[I,N. 
S9T.  leoquinUinf  is  present  iu  coal-tar,  from  which  HooGBmutrr- 
anri  VAN  DoBP  iHolatM   it   in   the   form  of   it»  MpariniJy  nolublf 
fii]lphaU>.     It  is  a  rnlnuripss  Aulistaixrc  with  an  ociour  like  that  of 
qtiiRoline;  it  iiiHtfl  at  2\°,  Mtid  h«il«  at  237°. 

The  following  tynthetix  iiidicjiu?)t  Iih  constitutinn.     On  heating, 

CH.  CX)OH  I 
2' 


18. 


C^.<       >NH. 


the  ninmomum  salt  of  homophlhalic  acid,  C«H4<(.qAii 
ooovert«d  into  fionuiphlhalimide: 

XH  COONH, 
C,H,<  -  211,0  -  NH,  -  v,^.,v 

NCOOXH.  \C0 

tli^Diniliilialimld* 

On  treating  with  phosphonis  oxj'cliJorido,  each  O-ntoin  is  replaced 
by  two  Cl-alonis,  2HC1  being  aubscqucntly  split  off,  with  fonuatioct 
of  dichlvroisoqmnoline: 

cHjn 

aioHl 


N. 


Y 

Dl  ch  I  or«lioq«i  In  nil  n  e 


ISOQi/INOUNE  AND  INDOLE.  509 

Reduction  with  hydriodic  acid  and  phoephoruB  converts  this  sub- 
stance into  isoquinoline,  which  differs  from  ordinary  quinoline  in 
that  the  N-atom  of  the  pyridine-nucleus  is  not  directly  linked  to 
the  benzene-nucleus. 

The  products  obtained  by  the  oxidation  of  isoquinoline  support 
this  view  of  its  constitution.  The  benzene-ring  is  removed  from 
one  part,  and  the  pyridine-ring  from  the  other,  so  that  cincbome- 
ronic  acid  (*W)  and  phthalic  acid  are  formed: 


HOOC/\  /^/N  /\COOH 

HOOC\/N  '•^X/N  \/C00h" 

Cfncbonieroiiic  odd  rhthalic  kcid 


Since  the  constitution  of  isoquinoline  is  decided  by  the  synthesis 
described  above,  it  is  thus  possible  to  infer  from  it  that  of  cincho- 
meronic  acid,  and  this  method  leads  to  the  same  conclusion  as  that 
previously  arrived  at  from  other  considerations  (loc.  cU.). 

m.    IKBOLE,    CgHfN. 

898.  The  relation  between  indigo  and  indole,  mentioned  at  the 
beginning  of  896,  is  made  evident  by  the  following  series  of  trans- 
formations, most  of  which  were  discovered  by  Baeyer. 

On  treatment  with  nitric  acid,  indigo,  C,bH,oN,02,  yields  an 
oxidation-product,  isalin,  CgHjNOj,  which  can  also  be  synthesized 
by  treating  o-nitrobenzoyl  chloride  with  silver  cyanide;  on  hydrol- 
ysis, the  resulting  nitrile  yields  o-nitrobenzoylfonnic  acid : 


C»H,<jTQ?j,j2-*C^«<CQ?Qj^-^CoH^< 


NO, 


COCOOH. 

robenxo 
chlorjdo  C7MiId«  formic  acid 


D-Nltrobeniojl  o-Nitrobenxo?!  o-Nitrobenxoyl- 

•        ■      .|d 


On  reduction,  the  nitro-group  in  this  acid  is  converted  into  an 
amido-group,  water  being  split  off  simultaneously,  and  isatin 
formed.  It  has  therefore  the  constitution  indicated  by  the 
equation 

o-AmtiiobeQMirirormic  add  !■■([□ 

On  reduction  with  zinc-dust  and  hydrochloric  acid,  isatin  takes  up 
two  hydrogen  atoms,  forming  dioxindole,  CaH^NOj.    This  com- 


5IO 


ORGANIC  CHEMISTRY. 


pwind  also  results  by  tlie  elinuiuition  of  wstpr  rrom  the  unstable 
o-aminomandelic  acid,  which  dcUrrmiiies  its  constilutioD  : 


Nil  H  /NH 

»-lKilBoa*D4»li«  mU  I 

OH 

Ijioxlndotn 

On  reduction  with  tin  and  hydrochloric  acid,  dioxiodolc  yialAx 
inindatt,  CgHiNO,  which  is  also  obtainoil  by  rc^uctioo  of  (MUlro- 
phciiylaoulic  acid  aud  suUswiuc-iit  cliniiiiation  of  water: 


C,H.< 


NHIH 


'ndtit. 


wn  tlislillfd  with  zinr-dust,  oxindole  is  convert-ed  into  ii 
C,H,X,  which  must,  thcrcforp,  have  the  sinicture  C,H,<^*^H; 
or,  written  in  another  way, 


NH 


/(  therefnrf  poiarsitfa  a  bmsmf-ttuetvu$  condenatd  mth  a  pj/mU' 
nufi^^s.  Il  d»e!<,  iQ  fai-l.  (li»|ilay  sumc  of  the  propertirs  character- 
istic of  pyrrnlr;  ihus,  it  U  a  very  wvak  base,  anil  giv<9  a  red  colour- 

atkni  with  hvdrt>chlnric  acitl. 

NH 

fi-MfihifiindaU,  or  ikatole,  C,H,^   ^f-'H*  •*  prweot   in   tee«. 

Tt  b  abo  found  in  a  spccini  of  wood  grown  bo  India,  aod  if 
formed  in  th«  putrefactive  decay  of  albutoio,  or  by  fusing  albomio 
with  caustie  potash.  Skatole  is  characterised  by  it<  dintgreeable 
odour. 

luljfo. 
The  constitution  of  indieo  is  inferred  from  its  formation  from 
itaiia  dUoridc,  obt^oed  by  the  interaction  of  isatin  and  phosphorus 


I 


INDIGO. 


s»» 


pentachlorido:  on  rPclucUoQ  with  zinc-dust  and  acetic  add,  it  is 
tnuisformed  into  indigo: 


N 


cjB.<(^>cci  +  ac<^>c»H, 


+   HH      H 


N 


H 


=  CJS,<^>C=C<  ^>CJI,  +  2Ha 

Sinceon  treatment  with  siilphurio  aeii!,  and  subsoquent  reduc- 


tion, o-dinitradi-pkitiyUiiactiylene, 


C.H,CsC~CsCC.H, 


13   COC- 


NO,  NO, ' 

verted  into  indigf'.  the  two  isfttiti-residues  in  the  latter  must  be 
united  by  a  rarbon  bond. 

399.  Indigo  ha«  long  liceu  known  as  one  of  the  finest  blue  dyes, 
and  is  very  permaiifnt,  (H-ing  unafT(>ctt*d  by  light,  aridx,  alkalis, 
or  nasliing.  It  is  prepared  Jrtmi  certain  plaata,  among  them  /nrfi- 
po/tTrt  t\nctaria  and  Ivploshfcka.  These  ore  eultivatrd  on  a  large 
scale  in  iit-ngal  in  Intha — whence  the  dye  deri\e»  ita  name — as  well 
as  in  Central  Americn,  Java,  and  other  countries.  IndJgo  is  not 
present  in  the  plant  an  siieh,  but  in  combination  at  the  f^lucoside 
indirnn,  which  is  chiefly  in  the  Inaves,  and  ean  be  extracted  with 
hot  water.  It  is  crystalline,  and  has  the  formula  C„1I,,N0,  +  3H,0. 
In  additinn  to  the  Klucoaiile,  the  leaves  contain  an  enzyme,  whose 
activity,  like  that  of  all  enzymes,  i«  destroyed  by  hntlivg  water; 
hence,  when  indienn  itseU  is  to  be  preparc<i,  hot  water  must  be 
employed  in  the  cxlraclion.  With  cold  water,  both  indican  and 
the  unchanged  enzyme  dissolve,  and  the  glucoeidc  splits  up  into 
glucose  and  indoxyl,  C,HjXt>.  or 

NH 


C,H,< 


C(OH) 


>CH, 


a  Hiibslaiicc  wliieh  \a  moderately  stable  in  acid  solution,  but  in  Hilute 
alkaline  solution  is  quickly  oxidized  to  indigo  by  atmottpheric 
oxyKCn. 

The  manufacture  of  indigo  from  the  plants  containing  it  is 
carried  out  by  the  method  indicated.  The  leaves  of  the  indigo- 
plant  are  allowed  to  remain  immersed  in  lukewann  wat^r  fnr  some 
hours;  the  aqueuu:!  extract  is  "eburned"  by  a  revolving  water- 
wheel  with  woaien  paddles,  which  aerates  it,  and  thus  oxidizes  the 
indoxyl  to  indigo.  The  oxidatioti-prncess  is  farilitated  by  the 
addition  of  slaked  lime  to  make  the  liquid  faintly  alkaline.    The 


5" 


ORGANIC  CHEMISTRY. 


indigo  formed  sinks  to  tlio  bottom,  ie  rcmovetl  by  filtrBtion,  and 
dried.    U  is  put  on  tlie  niarkui  in  tKc  fimu  of  Bmall  cubes. 

In  addition  (o  the  blue  dye,  iniiigoiin,  romintTcia]  indigo  con- 
tains inJiff>Kiuten,  iinliKf>-lm>wn,  and  intiiKo-rwI;  these  ran  be 
oxtraclcfl  by  watrr,  alroluil,  and  ulkalin,  in  whirh  indiKotin  \s  insol- 
ublf.  The  tattrr  '\3  u  dttrk-bluu  pwwdi-r,  which,  wlica  rublmd,  has 
ft  copp^r-likc  tustrc.  It  can  be  sublimed  in  vacuo,  so  that  it  is 
possible  to  dctprniinp  its  vnpmir  density.  It  is  insoluble  in  most 
solvents,  but  can  be  prj'stalliied  from  nilrobeiizonc  or  aniline,  U., 
dissolves  in  filming  gulphuric  acid,  with  formation  of  ailph 
acids. 

On  account  af  the  great  indii^txial  importance  of  indign,  maaj 
fttlcmpls  have  been  made  to  synthesize  it.    One  of  these  is  commer- 
cinlly  pviooessful,  (■nahtin;;  the  artifirial  priMhict.  to  be  sold  at  the 
enme  price  as  natural  indigo.     It  yieldi^  pure  indigotin,  whirh  m  aa . 
advanlagc  in  some  cases. 

Tliis  melhiid  is  employed  by  the  B.ADisriiE  Axiux-  vfiit  Soda- 
pAuatK  of  I.udwigehafen-nn-Rhiiie.     Aittliranilic  acid,  or  o-nniiiit>- 

benxoiio  acid  (351),  ^•H«<^,(j(^'j^.  rombines  with  monochloroacetic 

»cid  to  form  phciiylglycocoll-<^corboxylic  acid : 


^•"•^COOH 


NH|H  +  ClIiI^COjH 


_.  r  H  ^NH  H^C- CO,[H 

^ '"^^ClO  |0H  """      ' 

rbeiirl4tIro»oall-oacarbciK;ltc  b«Ii1 


Oq  f^ion  with  eatiMic  soda,  this  compound  is  trauafonaod  inUi 
indoxyl,  C,n4<p.,.i,.  :^CH,  which   in  alkaline    solution  is  con* 

verled  by  ntmo.'ipheric  oxidation  into  indipo. 

The  manufacture  of  indigo  by  this  method  has  been  rend- 
ered possible  by  the  discovery  of  a  satisfactory  manufacturing- 
jiroeess  for  anthranilir  arid.  This  substance  isnbtained  by  oxidizing 
naphthalene  to  phthalic  acid  <326),  which  can  \x  converted  into 
anthrunilio  acid,  with  intermediate  production  of  phthaliniide 
(351). 

On  reduction,  indigo  takes  up  two  hydn>gen  atoms,  with  for- 
mation of  indigo-whUe,  C^HiiXjO,,  a  wliite,  crystalline  substance, 
whose  phenolic  character  ia  pnn-ed  by  ils  solubility  in  alkalis.  la 
alkaline  eolutioo  it  is  speedily  reconverted  into  iudigo  by  atmoa- 


DYEING   IVITH  INDIGO.  513 

pheric  oxidation,  a  reaction  employed  in  dyeing  with  this  substance. 
The  dye  is  first  reduced  to  indigo-white,  and  the  fabric  thoroughly 
soaked  in  an  alkaline  solution  of  this  compound;  on  exposure  to 
the  air,  the  indigo-blue  formed  is  fixed  on  the  fibres.  This  process 
is  technically  known  as  "  indigo- vatting." 

The  reduction  of  indigo  to  indigo-white  is  variously  carried  out 
in  the  dyeing-industry  according  to  whether  wool,  silk,  or  cotton 
is  to  be  dyed.  Reduction  is  best  effected  with  a  salt  of  hyposul- 
phurous  acid,  HjSjO^  ("Inorganic  Chemistry,"  83),  for  the  two 
fcst  named.  The  solution  is  mixed  with  zinc  hyposulphite,  and 
treated  with  excess  of  milk  of  lime,  which  precipitates  zinc  hydrox- 
ide. The  indigo  is  mixed  with  water,  and  warmed  to  about  60° 
■with  this  solution  of  calcium  hyposulphite,  a  concentrated  alkaline 
solution  of  indigo-white  being  obtained  in  a  short  time.  On 
■adding  sufficient  water  to  this  in  the  dyeing-vat,  the  bath  is  ready 
for  use. 

The  hyposulphite  reduction-proc^s  possesses  the  advantage 
that  the  reduction  stops  at  indigo-white,  so  that  almost  none  of  the 
indigo  is  lost 


■i 


ALKALOIDS. 

400.  Plants  of  wrtain  ffliii5[ies  contain  substances,  usually  of 
complex  I'oinpcwitioii  and  basic  charac-icr,  callKcl  alkaioifis.     Thoir 
classificatioa  in  one  gtxjup  in  of  uld  Htaiicling,  ami  had  its  origin  in 
an  itlca  aiinilar  to  tlial  which  prr-vaiW  conctrning  the  vegt'lablo 
acid?;  (1)  prior  tn  Uic  iJctcTtiiinatKm  of  thpir  ronstitu tion.     JuHt  as 
the  latter  have  bran  subdiviiler^  into  diftercnt  classes,  such  as 
monobasic,  polybasic.  aliphatic,  and  aromatic  acids,  so  it  has  bt-wmic 
apparent  that  the  individiml  alknlouint  can  bo  nrranf;c<l  in  very 
difT^nnt  elafuM-!!.     MoKt  or  the  iilkaloiils  arc,  hon-evcr,  related  to 
pyritiine,  qiiinotino,  or  isnqiiinoliiip,  while  a  smaller  number  Ik-Ioe 
to  the  aliplmtir  series.    Some  of  the  latter  class  were  described^ 
along  with  the  compounds  of  similar  chemical  character,  aniuo^ 
them  are  betairu-  (200),  nntscarine  (232),  choline  (162).  caflcine  anc 
Ibeobromine  (248).     (.tnly  alkainiils  which  are  dcrivalivfj*  of  pyrid-1 
ine  will  be  desrriboil  here;  to  these    the    name  alkaloids,  in  its 
mote  restrietcd  sense,  is  applied,  the  other  substances  bein^  known 
u  VGigetabte  bases. 

401.  It  is  seldom  that  an  alkaloid  \»  pres*nt  in  more  than  one 
family  of  plants;  many  oE  these  do  not  contain  them.  Almost  alt 
alkaloids  are  pre»ipnt  in  dicotyledonous  planta.  Only  a  few,  sueK 
as  coniine  and  nicotine,  are  litjuids;  most  of  them  arc  erj-stalline. 
Many  are  optically  actU'e  and  la-'vo-rotatory,  it  being  very  excep- 
tional for  them  to  exhibit  dextro-rotation.  They  hove  an  alkaline 
n-artion  and  a  bitter  taste;  most  of  them  aiv  initolnblc  in  water, 
more  or  less  soluble  in  ether,  and  readily  soluble  in  alcohol.  Most 
are  inaoliiblo  in  alkalis,  but  dissolve  in  acids,  forming  salts  which 
are  sometimes  well-defined,  crj-stalline  substances. 


PROPERTIES  OF  THE  ALKALOIDS. 


5»5 


OtJDEBANB  obBcrvi>d  tliiit  tlip  gpecific  rotatOTj-  power  (ST,  S)  of 
the  alkaloid  t-alUi  of  atrouR  aeide  m  nqueoufl  solution  depends  only 
on  lh«  allcalnid,  aiid  is  not  iiiHutricpd  by  the  nature  of  iho  acid- 
radidc;  while  for  Ibt.*  salts  of  vrcak  acids  it  depends  on  the  nature 
of  botli  the  alkaloid  find  tlic  ftcid.  This  ia  accounted  for  by  the 
theoiy  of  electrolytic  diseociation :  vlien  dissolved,  the  Ralta  of 
strong  acids  are  almoEt  coniplcttfly  lomini^d,  so  that  in  solutions  of 
equiinolecular  concentration  tliero  is  always  the  ««ni»  amount  of  the 
optically  anive  cation  present ;  the  salts  of  weakscidii,  however,  are 
to  a  great  extent  nan-ioni2ed,  60  that  they  possess  u  different 
(oDulIiT)  Bpecilic  rotatory  power. 

Many  allcaloicis  can  W  ideiitified  by  eharaetcristiR  colour-rcao- 
tjons.  Some  substances  prpcipitatc  many  of  tlie  alkaloids  from 
tlieir  B(|Ucous  or  acid  solution;  siich  gcntral  nlktiloid-rfaiicnis  are 
ttiiiiiia  (345),  phoephnmnlyhtlic  acid,  mercuric  potaseium  iodide, 
KI-Hgl,  ("Inorganic  Chcmistn,'."  148  and  873),  and  othere. 
Some  alkaloids  aro  cxeeefuvely  pwisrmoua 

Strong  t*a  is  sometime*  employed  as  an  antidote,  the  tunnio 
present  precipitating  the  alkaloid,  and  rendering  it  innocuous. 

Most  of  the  alkaloids  air-  tertiar>'  amines,  so  that  they  yield  arldi- 
lion-piTMhicts  with  methyl  iodide;  none  of  them  possesses  the 
character  of  a  primarj-  amine.  Many  contain  acid- residues  or 
methoxj'l-grmips;  the  fonner  are  split  off  by  saponifieation,  effected 
by  healinp  with  bascB  or  aeida,  the  latter  by  heating  with  hydriodic 
add,  which  yieldH  methyl  iodide.  Hydrnxyl-gronps  ean  bo  ttnteii 
for  in  the  onlinary  way  with  acid  chlorides  or  acetic  anhydride  (98 
and  96).  On  ilry  dislillatitm,  or  nn  heating  with  zinodust,  sub- 
stituted pyridines  an?  eonictimrs  formed. 

On  account  of  the  complex  constitution  of  tlic  alkaloids,  the 
structures  of  ninny  of  them  have  not  hitherto  been  determined, 
80  that  a  rational  elaswiicatioii  is  not  yet  [jossible. 

402.  In  the  exirariion  of  the  alkahkU  Irani  planla  the  latter  are 
cut  Up  into  fine  pieces  and  lixi\iate(l  witli  acidified  water  in  a 
conical  vat  tapering  towards  the  bottom,  where  there  i.s  a  layer 
of  flome  material  such  as  glaea-wotd  or  lint.  The  cfTeet  of  this 
is  that  the  acidified  water  pradually  sinks  through  a  (hick  layer  of 
the  substance  under  extraction,  n  process  technically  knowu  aa 
"percohition."  Dyes,  earbohydratcs,  inoncianic  ealta,  etc.,  are 
dissolved  out  along  with  the  alkaloids.    When  the  alkaloid  ts  vols- 


5'6 


ORGANIC  CHEMISTRY. 


tile  ^ith  st«&m,  it  can  be  separated  by  this  means  from  the  liquid, 
after  making  tlic  noixture  alkaline;  when  it  is  comparatively  inaol- 
ublp,  it  fan  be  obtaJnpd  by  filtration.  Furthfr  purification  te 
always  ncfr^sxary,  Hiid  it;  cfTected  by  cryetallizuig  the  free  alkaloid 
or  one  of  iu  salts  several  times. 


IHDlVlDUat   ALKALOnM. 

CoDJine,  C.H,.N. 

403.  The  synthcsiK  of  coniine  is  described  in  388,  It  is  present 
in  spotted  henilook  (Conium  maculatum),  and  is  a  colourless  liquid 
of  stupefying  odour.  It  boils  at  167°,  is  but  slightly  soluble  in 
water,  and  is  veiy  poisonous. 

Hiootina,  C,oH„N,. 

404.  Nicotine  in  present  in  cnml»n«tlnn  with  malic  and  citric 
aeitJs  in  the  Iravrs  of  thr  lobacco-plant  {Nicotiann  tabacum).  It  is 
a  coloiirlrss,  oily  liquid,  whirh  is  la^vo-rotat-nry ,  and  readily  soluble  in 
wat-cr.  It  has  a  tobacco-iikr  odour,  which  is  not  nearly  so  marked 
in  a  freshly-distilled  sample  m  in  one  which  has  stood  for  eoine 
time.  It  boiU  at  246"*',  and  is  excessively  poisonous.  It  quickly 
turns  brown  on  exposure  to  air.  It  is  a  ditertiary  l>ase;  on  oxt^lalion 
with  potassium  permanganate,  it  is  converted  into  nicotinic  ackl 
(389) ,  proving  it  to  be  a  ^-dfrivalive  of  pyridine.  It  is  assumed  to 
contain  a  pyridine-nuclous.  and  a  hytlrogenatcd  pynole-nucleua 
whoee  N-atom  is  in  union  with  a  methyl-ftroup. 

Atropine,  C„H„NO,. 

105.  Atropine  is  present  iti  tlie  berry  of  the  deatlly  nightshade 
{AtrojM  beUadontia)  an<l  ill  tlie  thorn-apple,  the  fniit  of  Datura 
stramonium.  It  is  erj-stalllne,  mplt.i  at  llo-.')'',  and  is  very  poison- 
ous, il  exercises  a  "mydriatic"  action — that  is,  when  dropjjed 
in  dilute  solution  on  the  eye,  it  expaiiila  the  pupil;  for  this  n^asou 
it  is  employed  in  ophthalmic  surgery.  It  is  optically  inactive. 
On  heating  with  hydrochloric  acid  or  caustic  soda  to  120°,  it  takes 
up  water  and  splits  up  into^'optnc  and  tropic  acid  : 

C.,H„NO,  +  H,0  =  C,H„NO  -t-  C;H,„0,. 

Jktro(>lii«  Ttoplae  Tfopt«  add 

It  can  be  regenerated  from  these  two  substances  by  the  action 
of  hydrochloric  acid.  Atropine  is,  therefore,  the  tropine  ester 
of    tropic    add,   which    is    a-phenyl-^hydn>xypropionic    acid. 


HYOSCYAMINE,  COCAINE,  AND  MORPHINE.  S'T 

CbH,-CH<«5?jtt  ■  The  constitution  of  tropine  is  probablya 
carbon  ring  of  seven  atoms  with  a  "nitrogen-bridge," 

H,C— CH— <;H, 
N-CH,CHOH. 

H,c— CH — in. 

This  formula  explains  the  formation  of  various  substitution-pro- 
ducts, derivatives  of  tetrahydropyrrole*  or  pyrrolidine  (ring  I),  of 
piperidine  (ring  II),  and  of  heptamethylene  (external  carbon-ring). 

Hyoicyamine,  C„Hj,NOj. 

406.  Hyoscyamine  is  isomeric  with  atropine,  into  which  it  is 
■converted  by  the  action  of  alcoholic  potash;  it  can  also  be  split  up 
into  tropine  and  tropic  acid.  The  isomerism  is  probably  stereo- 
chemical. 

Cocaine,  CHaNO^. 

407.  On  account  of  its  use  as  a  local  amesthetic,  cocaine  is  the 
best  known  of  the  alkaloids  present  in  coca-leaves  {Erytkroxylon 
coca).  It  is  crj'stalline,  is  readily  soluble  in  alcohol,  and  melts  at  9S°. 
On  heating  with  strong  acids,  a  benzoyl-group  and  a  methyl-group 
are  split  off,  with  formation  of  ccgonine,  CjHjjNOj,  so  that  the 
formula  of  cocaine  may  be  written  C,H„NO,(OCH,)(COCoH():  by 
benzoylating  and  methylating  ecgonine,  cocaine  is  regenerated. 
Ecgonine  is  a  carbonyl-derivative  of  tropine. 

Morphine,  C,jH„NOs. 

408.  Morphine  is  the  longest-known  alkaloid;  it  was  obtained 
from  opium  in  1806  by  Serturner.  Opium  is  the  dried  juice  of 
the  seed-capsules  of  Pnpaver  somniferum,  a  variety  of  poppy.  It 
is  a  very  complicated  mbcturc,  containing  caoutchouc,  fats,  resins, 
gum,  sugar- varieties,  albumia^,  mineral  salts,  meconic  acid,  some 
more  organic  acids,  and  other  substances,  together  with  numerous 
alkaloids.  Twenty  of  the  last-named  have  been  identified;  of  these 
morphine  is  present  in  largest  proportion,  and  constitutes  about  10 
per  cent,  of  opium. 

Morphine  is  crystalline,  and  melts  with  decomposition  at  230°; 

*  Of.  (ootnot*.  p.  4TO. 


5i8 


ORGANIC  CHEMISTRY. 


it  is  slightly  soluble  in  wat^?r,  without,  odour,  nnd  is  pmpioyed  as  an 
aiindv'Tie  rimI  narcolic.  On  distillation  with  zinc-dust,  it  yiclils 
pymjie,  pyridine,  qumolinc  nnil  pliensnthrene.  It  is  a  torliiry 
base,  an<l  also  possesses  a  phenolic  character,  since  it  is  soluble  in 
alkalis. 

Narootine.  CjjHj^'O,. 

409.  NareoHne  is  )>rosent  io  opium  to  the  extent  of  about  6  per 
cent..  it«  percenlas'^  bfiiij;  next  to  that  of  inorpliinc.  Il  is  cn,-stalline, 
melts  at  178*,  and  is  slightly  poisonous.  It  \»  a  weak,  tertiary 
banc,  it»  salts  readily  undergoing  h>*droIylic  decomiKwilioti.  It 
contains  llirre  mctlioxyl-jKroiips,  so  that  its  fornnila  can  be  mitten 
C,4I„N'0,(OCH,)3.  jVormxwCnc  lins  the  fomnila  C„II„NO,(OII),. 
On  hydmlysis,  nnrcolJnp  yields  the  anhydride  of  moconinic  acid, 
or  mrrrmin,  C,„H,oO,,  and  fotaminr,  Ci,I],,NOg,  which  is  a  di-riva- 
tive  of  isoquinoline.  HroniiDe  coDverts  narcotine  into  dibromo- 
pyridine. 

doinine,  C'jjH^NjOi. 


410.  The  bark  of  certain  trees  of  the  Cinthona  and  Rem 
families  contains  a  prtat  number  of  nlkaloiibt;  of  these  twcnty-four 
have  been  i-fnlated,  hut  it  is  pmbuble  that  more  am  present.  The 
most  important  of  th^-m  is  quimnc,  nn  ari'nnnt.  of  its  antt-febrile 
(ffeet  Citiffioninr.  C„HjjN,0,.  is  the  next  hpst-knnwn;  its  phjTsio- 
lugienl  prtion  is  similar  to  that  of  qninine.  but  less  pronounced. 

Ilk  addition  to  alkaloids,  these  barks  cont^n  Tarious  acids,  sucli 
Ad  (luinic,  quinovic,  and  qiiinotannic  acids;  indiffeTcnt  subetances, 
such  as  iniiiKivin,  quina-red.  etc..  are  al«)  pxeeeat. 

Quinine  is  wry  slijihliy  soluble  in  water,  and  a,  lievo-rotatory; 
in  the  anhydrou.*  stale  it  luelts  at  177*,  and  at  .57°  when  il  con- 
tains thnr  nKileculfsof  waterof  crystalhr-ation.  UisualronEbusc. 
and  both  N-atoms  are  tertiftry.  It  unites  willi  tvro  equivalents 
of  an  acid.  In  dilutir  solutiun  the  salts  of  quinine  c.'diibil  &  splendid 
blue  fluorescence,  which  serves  as  a  test  for  the  base. 

The  eonatitution  of  quinine  has  been  partially  elucidated,  chiefly 
througb  the  researches  of  Kon«;s.  It  seems  to  contain  two  ring- 
systems,  and  to  possess  a  hyclro.xyl-group  and  a  mcthoxyl-group, 
8o  that  its  formula  may  be  written 

CH,0-C4I,N-C„H,»(0H)X. 


J 


STRYCHNINE. 


5'9 


^"ecordantc  with  the  nomenclature  in  396,  the  first  of  these  riiig- 
Q'stems  is  G-niethuxytiuiruilitip,  a  wtnp<nin<l  which  is  obtained 
by  fudng  (|uiiiiiie  \vith  catintie  [Kitash.  The  second  ring  is  prob- 
ably similar  to  the  one  assiitned  to  be  present  in  tropiue  (406). 

Strychnine,  C,tHjjN,Or 

411.  Three  extremely  poisonous  ulkuluuU,  6try<Jinine,  hrucim, 
and  curarinf,  arc  present  in  the  seeds  of  Slryciinns  nw-J  I'^micu,  as 
well  at  in  others  of  the  Strychnos  fnmiU'.  lattle  is  known  of  the 
chemical  nature  of  curarine.  although  it  has  been  much  studied 
from  s  physiological  stan(l|)oint ;  whrn  atlm inist<>reiJ  in  sniail  doses, 
it  produces  total  paralysis.  Strychnine  and  bnicine  cause  death, 
preceded  by  tetanic  spaama — that  is,  contraction  of  the  muscles; 
ourarino  is,  therefore,  employed  an  an  antidote. 

Stryehnine  id  crystalline,  and  tnclta  at  265° ;  it  is  altuost  icuKiluble 
in  water.  It  ia  a  monoliydrie,  tertiary  baae,  only  oni>  of  its  N-atonia 
exliibituig  basic  propertiL<£.  On  futiiuii  with  caustic  potash,  it 
yields  quinoline  and  indole;  and  when  distilletl  with  slaked  lime,  it  ia 
converted  into  ;3-ptcoline  (38&).  Heating  with  slnc-dust  produces 
c&rbftzolo(379>au(lother6ubstAace8. 


AIBTJUms. 

418.  This  section  contains  a  short  account  of  the  albumins, 
which  are  compounds  of  great  importance  in  the  animal  ami  vege- 
table kingdoms,  but  of  such  complicated  stnicture  that  their  chem- 
ical investigation  is  a  matter  of  extremr  difficulty.  Their  great 
phvfiologieal  importance  is  made  apparent  by  the  fact  that  the  dry 
material  in  animal  bodies— apart  from  the  mineral  constituents  and 
fat« — (ron^sls  almost  wlioUy  of  albumins,  by  tht-ir  being  an  esKenttal 
consiliiupiit  of  each  living  plaiit-eell,  and  by  their  forming  the  most 
important  part  of  liuman  and  animal  food.  An  aiiinml  can  exist 
without  i&ls  and  carbohydra.l'eA  for  a  protracttnl  iK'riod,  btit  its 
death  is  assured  by  the  withdrawal  of  albuniins  from  its  nourish- 
ment. 

The  investigation  of  the  albumins  i.'J  rendered  difReult  not  onlv 
by  their  complicated  Ktnirture,  hut  a\t^  by  the  fact  that,  with  few 
exceptions,  they  do  not  crj-stallize,  and  cannot  be  di.stilled  without 
undergoing  dccnnipnsition,  so  that  advant,age  cannot  be  taken  of 
t<h«K  valuable  luib  in  the  itiolation  uf  individual  eubstances.  More- 
over, many  of  the  albumins  ehanRo  very  readily  into  other  sub- 
stances, and  the  distinctions  between  the  different  varieties  ftro 
sometimes  by  no  means  marked. 

The  aibiimins,  proUids,  and  olhuminoids  are  closely  relatwl,  and 
Are  cloaseil  together  imdcr  the  name  proteins.    The  true,  or  native 
allmiiiins  will  be  first  considcrctl.     Since  they  aometiinea  exhibit 
great  differences  in  physical  an<l  chemical  behaviour,  it  is  nece^acy 
to  first  state  the  general  properties  charaetoristic  of  the  albumins. 

They  contain  only  five  elempntfi,  and  do  not  fliPfer  much  from  OMJi 
another  in  comjKtKitJon.  an  the  following  table  shows : 

Carbon 50-55  per  cent. 

Hydrogen 6- 5-7 -3        „ 

Nitrogen 15-17-6     ,. 

Oxygen 19-24  „ 

Sulphur 0-3-2-4        „ 

Those  of  one  variety,  called  nueieins,  also  contain  phospVio 


ALBUMWS. 


5»« 


r 


Both  nitrogen  and  sulphur  arc  linked  in  the  albumin  molecule  in 
more  ways  than  one.  A  portion  of  the  nitrogen  is  readily  eliminated 
in  the  form  of  ammonia  by  treatment  with  a  hot,  dilute  solution 
f  caustic  potasli.  although  the  greater  part  is  not  removed  by  this 
means.  On  warming  the  albumins  with  caustic  potash,  a  portion 
of  the  sulphur  is  similarly  spht  off  in  the  form  of  potawium  sul- 
phide, which  can  be  recognized  by  the  formation  of  a  black  precip- 
,il«le  of  lead  sulphide  on  addition  of  lead  acetate;  ihc  remainder  of 
sulphur  can  only  bo  tletected  by  completely  breaking  up  the 
te,  which  isetTecte<l  by  fusion  with  caustic  potash  and  potas- 
sium nitrate.  It  frtllnn's  that  the  albumin  molecule  must  contain  at 
least  two  atoms  of  mlphur. 

Up  to  the  present  it  has  not;  been  poR=dblc  to  give  an  empirical 
formula  for  albumin:  attempts  to  detcniiino  the  molecular  weight 
by  the  eryoscopic  method  (14)  lead  to  tiie  conclusion  that  tt  must  b* 
verj'  great,  the  number  obljiined  being  about  15,000. 

413.  The  8olu(4<uis^of  the  albumins  are  all  optically  active  and 
Iffvo-rotatory, 

The  albnminK  are  collwida  ("InorRanie  (lhejnLsir>-,"  186) — that 
i«,  do  not  diffuse  thrfiugh  parchment-paper.  Advantage  is  often 
taken  of  this  in  sepfirating  them  fmiii  rbU.'!!  and  other  crystalloids 
(foe.  ct'r).  Very  few  have  been  ohtainerl  crystalline,  among  them 
serum-albumin;  most  of  them  are  white,  amorphous  powdvrs 
with  no  definite  melling-pf>int.s.  (Jn  heating,  they  carbonize,  with 
evolution  of  gOBes. 

Some  albumins  can  he  "  salted  out ''  from  their  solutions,  others 
-Muinot.  This  is  an  important  aid  in  identifying  and  separating  the 
different  varieties ;  usually  eumoiun  »ialt  or  magnesium  sulphate  is 
empIovL'd.  It  is  n^markable  that  not  only  all  albumins,  but  pro- 
teins in  gL-neral  ran  be  coniplcicly  "salted  out"  from  llu-ir  k»1u- 
in  both  neutral  and  acid  liquids  by  saturation  with  ammonium 
phate.  The  naltvo  albumuis  can  be  fractionally  precijjitated 
aqueous  solutions  by  gradually  increasing  the  eoneentration  of 
c  ammonium -sulphate  solution.  The  point  of  concentration  at 
'hieh  a  salt  begins  to  precipitate  an  albumin  i.s  just  a.s  charac- 
ristic  for  the  latter  as,  for  example,  the  solubility  is  for  a 
crystalline  substance.  ftTien  the  '*  salting-out 'I  is  effected  at 
ordinary  temperatures,  it  causes  no  change  in  the  properties  of 
the  allnmiins;  their  solubilities  are  the  same  after  as  before  the 
operation. 


tJous 


i" 


ORGANIC  CHEMISTRY. 


Addition  of  alcohol  precipitates  the  atbuminB  UDchim|;:ed  rroro 

•  an  aqueous  solution;  strong  alcohol  cc<t^uiai<a  them,  as  tiao  does 

IbeBtiug  with  water.     Fur  each  native  albumin  there  i;:  a  definite 

looagiilatioii-poiiit;  in  other  words,  tacli  alhumin  cnaftnlatni:  at  a 

definite  temperature.     On  coagulation,  the  differences  in  Ntlnbilitr 

between  the  albuniniK  viuilsh;  they  arc  all  rendered  insoluble  in 

neutral  wolventK,  and  can  Ik-  hroughl  into  snliition  apun  only  by 

treatment  with  dilute  caustic  alkalis  or  with  mineral  acids.    A  solu-^ 

tion,  which  behaves  exactly  like  those  thus  obtained,  c&a  be  pr^* 

pored  by  boUiofr  uneoBgulaled  albumins  nith  a  large  cxoam  of 

acetic  acid  or  with  caustic  alkali. 

In  this  process  the  native  and  coajzidated  albumins  undergo  a 
Ichanp'.  which  is  calle<l  dmaiuralion.  When  this  is  effected  with 
Lalkali,  the  product  is  termed  an  aJbumiTuUe  ;  when  an  arid  is  eni- 
ploywl,  a  eyntonin  or  and  albumin.  Botli  these  eubstanccs  differ 
in  composition  from  the  ordinary  albumins;  since,  as  mentioned  in 
413,  when  thuR  treiitrd.  they  oplit  off  nmnionia  and  sulphuretted 
hydrogen.  The  albuminate  nnd  .vyntonin  are  quite  insoluble  in  water, 
and  arc,  therefore,  precipitated  by  neutralizing  their  solutions. 

414.  DfcimijwjfitioTt' products. — I*rn!(»nped  Ixiiling  with  dilute  al- 
kalis or  mineral  arid»  dcconipoHcs  the  albumins,  water  being  taken 
up.and  ammonia,  sulphuretted  hydrogen,  and  a  series  of  amino-acids 
formed.  Sinee  these  eonstituu-  ihc  decoriiposilion-produeta  of  sU 
albumins,  it  follows  that  the  latt^-r  only  differ  from  one  another  in 
the  proportions  in  which  the.sc  are  present.  These  amino-acids  are 
tyuaim  (347)— which  proves  that  the  albumin  molecule  conioina, 
benzene-nuclei — latcine,  aspartic  add,  amino^utaru:  or  gliUeuninic 
0<n'rf(200);  diamino-acids,  ftueh  as  amilhinf  (200),  itrffinine  {2M) 
id  others,  are  also  obtained;  of  all  Ihese  leucine  is  formed  in 
^greatestaniovint.  Tlie  same  amino-acids  a.Tv  produced  by  (he  actiun 
of  the  ferment  tri/psin,  which  is  pawiit  in  the  pancreatic  gland: 
decompoation  due  lo  putrefactive  decay  produces  onimatic  com- 
pounds, such  as  inddc,  skataU,  phenylacelie  and,  fKnuA,  cthoI,' 
and  60  on,  in  larger  proportion.  It  is  probable  that  the  nitro* 
genous  substances  arc  the  primary  decomposition-products ;  while 
such  substances  as  earbonic  arid,  acetic  acid,  and  its  bomo- 
loguta  up  to  caproi'c  acid,  formed  by  an  oxidizing  action,  or  by  the 
^action  of  caustic  alkalis  or  of  acids,  on  the  albumins,  are  probably 
iuoed  by  the  subsequent  decomposition  of  the  amino-aeids. 


ALBUMINS. 


5*3 


The  albumins  are  precipitated  from  solution  by  various  sub- 
stances, either  by  coagulation  or  by  the  formation  of  comjiounds 
in«ihible  in  water.  Coagulation  is  effectecl  by  the  addition  of  min- 
eral acids,  preferably  nitrii:  acid,  since  an  exotrss  of  hydnwhloric  and 
[Other  acids  rediseolves  the  albumin,  with  fonnatioo  of  a  ayntooin; 
this  (loes  not  take  placo  with  nitric  acid. 

The  fonnalion  of  cnmpnimds  insoluble  in  wat*>r  results  on  addi- 

,  lion  of  salt«  of  most  of  the  heai'y  metals,  especially  copper  suljtliale, 

kferric  rhloride,  and  an  acidified  solution  of  mercuric  chloride.     Tlie 

Sumiiis,  therefore,  brhave  like  weak  adds,  which  with  the  o\iili» 

f^bflBemetalsyieldcompoulld9o^  the  nature  of  salts.     Tfaia  acidic 

iture  Is  indicated  by  the  fact  that  neutral  solutions  of  aJbuiuin 

[partly  disfe-olve  freshly-precipitated  ferric  hydroxide.     The  fomm- 

'  tioa  of  eo()f)er  a1btm)inali>£  furnishes  a  gooil  tnethnd  of  obtaining 

lumins  free  from  lumeral  coiistituent.s.  which  are  alwa^*)!  present 

I A  greater  or  less  extent ;  on  addition  of  an  iui<l  to  these  copper 

cnmpouud.-4,  the  ulbumlti  ja  set  free  af;ain  in  the  dcnat  urrrl  state. 

Some  weak  atids  yield  insoluble  compounds  with  albumin,  which, 
therefore.  Iwhavr-s  also  like  a  ho^c;  in  this  respect  it  exhibits  com- 
I>Ie1e  aralogj'  t-f)  it.s  main  decompositifin-products,  the  amuio-arJds. 
Among  these  weak  aeids  are  tannic  arid,  pin-ic  acid,  jthospliotun'isU'r 
ccid,  and  others.  The  albumins  are  completely  precipitated  fruui 
solution  by  phoephotungstic  acid,  a  metho<l  employed,  along  with 
of  coagulation  by  boiling,  and  precipitation  with  alcohol,  ui 
rate  liquids  from  the  albumin  dissolved  in  them.  The  acitUc 
and  baaic  properties  of  the  albmnino  recall  thtMo  of  tho  poeudo-acida 
(381)  and  (Jseudii-haitPB  (S80);  tluiK,  in  the  frw  state  they  have  a 
neutral  reaction  towards  uidiealnre,  but  the  reaction  remains  neu- 
trvl  when  stronu  iicida  and  Iwu-m-s  arc  added  (281). 

415.  Various  Icstx  jar  olbumiTUs  arc  known,  among  which  the 
following  may  be  mentioned. 

1.  MiUon's  n-a^ent,  which  is  a  solution  of  mercuric  nitrate  con- 
laining  nilroui^  acid,  yields  a  red,  coagulated  mas»  on  boiling. 

2.  Tito  rnntfimpwtrin-rfueU'nn,  which  consists  in  the  foraiatitm 
of  a  yellow  colouration  on  treatment  with  warm  nitric  acid. 

3.  The  biuni-rcmiion,  which  depends  upon  the  formation  of  a 
fine  violet^re<l  colouration  when  caustic  potash  is  added  to  all>u- 
Biin,  and  Ihen  a  dilute  {2  per  cent.)  solution  of  copper  sulphate 
drop  by  dmp.  Thia  reaction  derives  its  name  from  the  fact  that 
biuret,  rm  ffluiilar  treatment,  gives  this  colouration  (2&3). 


S»4 


ORGANIC  CHEMISTRY. 


The  albumins  can  be  classified  into  the  following  proups, 

1.  Native  or  true  albumins,  which  arc  srubilincied  into  four 
groups. 

(q)  The  albumins,  including  »eruin-albuniin,  egg-«lbumln,  milk- 
albumin,  miiscloslbuniin. 

(6)  GlobuliiM,  inctiiiling  serum-globulin  and  vegetable-globuUii. 

(c)  Coagulablc  aUAtmvm,  including  fibrinogen,  myofdo,  and  ^u- 
ten-protekiis. 

trf)  XueUa-atbumina,  in(?tu(ling  casein  and  vitcUin. 

3.  Becompositlon-prodDctB  of  the  trne  albnmlni. 

(a)  Dtnatunil  atbumiits,  including  acid  albumins  (ayntonins) 
and  albuminates. 

{b)  AlbumoKB  and  peplorus. 

3.  Proteids,  compounds  of  albumin  with  other,  usually  very 
complicated,  eubstanccs. 

(a)  Nitdea-proU'ids,  compounds  with  nucleHo  add. 

(fc)  HirmoglobiTW. 

(r)  Gtueo-proitids.  compounds  with  carbuhydrates  (mucins). 

4.  Albuminoidi. 
Some  particulars  may  be  g^vcQ  roganling  the  various  claasn' 

namvd. 

The  aibumins  arc  thp  host  known  and  most  readily  obtained  of 
the  albuminous  boilirs;  all  of  them  form  welUleRned  cr>-slai8, 
and  are  therefore  among  the  few  substances  of  the  class  which  are 
known  to  be  individual  chemical  compounds.  Th^  fUsmh-e  in 
water,  and  tn  dilute  acids,  nlkali»,  and  .snlt:-f^olutiaiis. 

Their  neutral  erilutione  cannot  be  salted  out  with  nodium  chloride, 
magnc^um  sulphate,  or  a  scml-saturatcd  solution  of  ammonium 
sulphate — a  method  of  separating  them  from  the  globulins,  which 
always  occurs  along  with  them. 

The  globtiiins  arc  further  distinguished  from  the  albumimt  by 
being  insoluble  in  water,  although  they  dissolve  in  dilute,  neu- 
tral salt-soluttune,  and  in  solutions  of  aUtali-carbonates.  At  30" 
they  can  be  completely  salted  out  by  magnesium  sulphate,  and  partly 
bj'  wdium  chloride.    They  have  not  been  obtainc^d  crystalline. 

Coagulahip  albumins  have  the  property  of  assuming  the  glaronus 
state,  intermediate  between  solution  and  ctiagulatlon.  In  this  con- 
dition they  arc  itiNtlublc  in  water  and  salt-aolutions,  but  ran  be 
made  to  coagulate  uiitlcr  llic  influcuet:  of  heat,  strong  aloobol,  etc- 


ALBUMINS. 


5«S 


1 

I 


■ 


The  nxicUo-albumim  contain  phoephoms,  and  for  this  reason 
formeriy  classed  ■with  the  nucleo-proteids  (416).  Thoy  are 
iWpty  (iistinguiBhed  froni  them,  however,  by  yieliling  xanthine 
baseH  flinuiig  their  dectiinpuidtitm-product*.  The  iiucleti-albuniins 
have  H  dUliiictly  acidic  character;  all  (if  iherii  turn  bhie  litmius  red, 
and  in  tlic  free  atato  art  cmly  eliKhtly  soluble  in  water,  though  readily 
«ohibl«  in  Uic  form  nf  thrir  alkuU-Kalt^  or  aiiinu}n)uiii  saltis.  The 
aolulions  of  their  salts  do  not  coagulate,  and  can  be  boiled  without 
undergoing  any  change. 

Dcnaturtd  albumin  was  referred  to  in  413. 

Albumosts  and  pcpfones  can  be  obtained  from  all  prot«Ins  by 
'suitable  hydrolyss.  They  have  the  albumin  rharnrler.  boing  insol- 
uble in  alcohol,  and  an-swering  to  the  xanthnprntein-tcjit  and  biuret- 
test  (415,  2  and  S).  They  rn^iilt  from  the  notion  of  gastric  juice 
on  proteins,  Tlicy  an-  to  Ik-  looked  upon  as  intf  rnicdiatc  products 
in  the  hydrolysis  of  albumins,  the  albimioecs  being  nearer  tlie  pro- 
tcina.  and  the  pcploiies  nearer  the  aniiiio-acids. 

The  albunioscfi  arc  the  soluble  decoiupusiiiun-produets  of  albu- 
m :  they  cannot  be  coagulated,  but  can  bo  salted  out  by  Kahs  such 

aiiununium  sulphate. 

The  peptones  arc  the  final,  raniptesl  decomposilion-produeta  of 
the  iifttiv*  albumins;  their  colour-reactions  (especially  the  biurct- 
reaction),  their  contttitiition,  and  their  physiolngieal  behaviour 
indicate  that  thoy  should  bb  Hassed  with  the  albumins,  but  they 
caunot  undergo  further  dceomposiUon  without  being  eonvertcd  into 
substances  of  wholly  different  character,  the  aniino-acids. 

416.  Nearly  related  to  the  true  albumins  are  the  proieids,  com- 
pounds of  albumin  with  other  subslancee,  usually  of  a  very  com- 
plex nature.  Like  the  true  albumina,  they  are  insoluble  in  alcohol, 
by  which  most  of  them  are  eoagulaltnl. 

Xueieo-proUids  derive  their  name  from  the  fact  that  they  are 
the  prineipal  consUtueni  t>f  the  cell-nuclei.  Tliey  are  compounds 
of  albumins  with  nitdcins — that  is,  compotmds  of  albumin  with 
phosphoric  acid  or  a  nucleic  acid.  A  nucleic  acid  ia  piKisphoric  acid 
which  is  partially  saturated  by  uuion  with  basic  substaiifcs,  such 
as  hj-poxan thine,  guanine,  xanthine,  etc.,  and  is  to  be  looked  upon 
as  an  amide.  The  composition  of  the  nucleTns  differs  eonsiderably 
from  that  of  the  inie  albumins;  Iheyeonlnin  about  41  per  cent,  of 
on,  31  per  cent,  of  oxygen,  and  57  percent,  of  phosphorus. 


5>6 


ORGMHIC  CHEMISTRY. 


The  nucleTns  have  a  markeflly  acidic  character;  thoy  are  insol* 
able  ID  water  and  dilute  acidi:,  bul  snluble  in  caustic  alkalis.  Tbey 
answer  to  the  same  coUiur-tPsts  as  the  albumins. 

There  is  not  much  djffereni^  in  c mnpfisition  between  the  nucleo- 
proteiidB  and  the  tnic  albuniuis.  this  being  due  to  the  small  amount 
of  nucleVn-siibstaiicc-  prceent  in  the  former.  They  contain  phos- 
pbfiniB,  wliirh  in  prewnt  in  the  iiiiHpin.  and  arp  more  aci<Ue  than 
the  albumins,  having  the  character  of  a  dibasic  atnd. 

HcFmogltilfinx  art?  c'iini]>()umis  ut  albumins  with  dyes  contauiing 
iron,  lucniuf;)ubin  bfi»K  tht-  tlyc  nf  ntl  bliMid-nirpuwIfS.  It  splitJi 
up  bito  atbimiin  and  h(rmatin,  and  unites  vcr>-  readil}-  with  oxygen, 
fomiinK  oxuktmotitobin,  fn>m  whitli  the  oxygen  is  cUnunAtcd  by 
placing  it  in  a  vppuum  or  treating  it  with  reducinp-agent«.  For 
this  reason,  hirmnglobin  plays  an  impcinant  port  in  respiration.  It 
unites  with  earbon  nionnxidp  lo  form  carboniilfia-moiflobm,  whioli  w 
unable  to  fond>iiie  with  oxygen;  on  this  depends  the  poisonous 
action  of  carlxtn  moiutxide. 

On  treatment  with  acetic  acid  and  sodium  chloride,  oxyha-mo- 
globin  yielda  the  hydnK-hloriric  of  hiematin,  called  h<xiniti,  which 
crj-Hlallixes  in  flharat^teristie,  microsntpie  needles  of  a  brown-red 
col'iiir.     This  rcaetion  fiiniishes  a  <le!ipatB  test  for  blood. 

Olaco-jirou'itls  are  cuiiipound^  uf  albumins  and  cad>ohydrates. 
To  them  lielonK  the  mucins:  tliese.  like  the  mic  let  (-albumins,  are 
acidic  ill  character  and  in«ihible  in  water,  but  soluble  in  n  sinall 
quantity  of  lime-water  or  alkali  eiiluticin.  The  solution  thu«  obtained 
is  neutral,  has  a  f;lutinous  appcaratioe,  and  is  not  coagulato^l  liy 
boiling-  Unlike  tliose  of  the  true  atbumins,  these  solutions  are 
not  prwipitatetl  by  nitric  acid.  When  Ixiiled  with  ariiU  or  eauatio 
alkfdiit,  they  yield  either  syntonins  or  peptones,  together  with  eai^ 
bohydra1<*.  Tlie  prest-nce  of  the  nitnigen-free  rarbnhydrales 
makes  the  iHTCentaKe-aniount  of  nitnij^en  in  the  murint^  coii-siilerably 
lest)  than  iu  the  true  albuminfi;  iUt  value  lies  brtwcon  11-7  and  12-3 
per  cent. 

417.  The  albuminoids  differ  somewhat  more  in  compoeition 
from  ihc  true  albumins.  They  exist  only  in  the  animal  eeononi}'  in 
the  undissolved  state,  being  the  organic  coustilueut  of  llie  akelctoa 
and  tlic  epidermis, 

Tlify  include  various  substaacea,  among  Uiein  being  ceraiiu, 
daatin,  and  collagen. 


ALBUMINS.  527 

Ceratin  is  the  principal  constituent  of  the  epidermis,  hair,  nails, 
hoofs,  and  feathers.  It  is  particularly  rich  in  sulphur,  of  which  it 
contains  between  four  and  five  per  cent.,  a  portion  being  readily 
removed  by  treatment  with  boiling  water.  It  can  be  dissolved  only 
by  boiling  with  caustic  alkahs,  or  by  the  action  of  high-pressure 
steam.  Its  decomposition-products  resemble  those  of  the  true 
albumins.  With  nitric  acid  it  gives  the  xanthoprotein-reaction; 
this  is  the  origin  of  the  yellow  colour  developed  when  nitric  acid 
comes  into  contact  with  the  skin. 

Elastin  constitutes  the  elastic  fibres  present  in  tissue,  which  in 
some  parts  of  the  body  are  united  in  the  form  of  ligaments,  Oo 
warming  with  dilute  caustic  potash,  aH  the  sulphur  in  it  is  eliminated, 
which  distinguishes  it  from  other  albumins.  The  decomposition- 
products  obtained  by  boiling  it  with  concentrated  caustic  potash 
have  the  same  qualitative  composition  as  those  obtained  from  the 
true  albiunins.  It  is  quite  insoluble  in  dilute  acids  and  caustic 
alkalis. 

The  etiUagens  are  the  most  widely  distributed  of  the  albuminoids. 
They  are  among  the  constituents  of  cartilage.  In  some  respects  they 
differ  from  the  true  albumins.  They  have  a  higher  percentage  of 
nitrogen  ( 1 7 ■  9  per  cent.).  They  do  not  contain  aromatic  nuclei, 
so  that  tyrosine  is  not  formed  by  their  hydmlytic  decomposition. 
Another  decomposition-product,  glycocoll,  is  produced,  which  is  n<jt 
obtained  from  the  albumins;  at  the  same  time  leucine,  aspartie 
acid,  and  glutaminic  acid  arc  formed.  The  collagcas  are  further 
distinguished  by  not  possessing  sulphur  so  readily  split  off  as  that  in 
the  albumins. 

When  boiled  with  water,  the  coUagens  take  it  up,  forming  glutm 
or  glue.  A  solution  of  glue  is  not  precipitated  by  nitric  acid,  or  other 
mineral  acids,  but  is  by  mercuric-chloride  solution  in  presence  of 
hydrochloric  acid.     It  is  also  precipitated  by  tannin. 

418,  In  the  inferior  orders  of  animal  life  a  series  of  substances 
has  been  discovered  whose  chemical  properties  approximate  more 
or  less  closely  to  ihose  of  the  collagens  and  also  of  elastin.  Among 
them  is  ajxtng-'ii,  the  principal  constituent  of  sponges,  which  is  much 
more  stable  towards  caustic  soda  and  barj-ta-water  than  collagen. 
On  complete  hydrolysis  by  boiling  with  dilute  sulphuric  acid,  it 
yields  leucine  and  glycocoll,  but  no  tyrosine,  pro\Tng  it  to  be  a 
eollagen. 


538 


ORGANIC  CHEMISTRY. 


Od  prdoD^d  boiling,  silk  splits  up  into  fibroin,  which  is  not 
decomposed  by  water  even  at  200°,  and  sericin,  or  mlkr^ne,  which 
is  perhaps  a  mixture  of  glue  and  albumins.  Fibrom  diaaolves  very 
readily  in  strong  acids,  ammonia  being  mmultaneously  split  off, 
and  sericoin  formed.  On  complete  hydrolysis,  fibroin  yields  tyxoe- 
ine  and  giycocoll,  but  no  leucine. 

Lastly,  come'in  may  be  mentioned;  it  is  the  organic  constituent 
of  coral.  On  hydrolysis,  it  splits  up  into  leucine  and  an  aromatio 
substance  of  unknown  composition. 


N 


INDEX 


Tha  prinoipal  retotwioeB  un  Ln  old-atyle  Gfurao. 


A. 

ASEL,  Sis  Frederick,  40 
Absolute  alcohol,  55. 

Test  for,  66. 
Aoetaldehyde,  66,  127,  129,  133-138. 
146,  158,  168.  173,  180,  185,  220, 
221,  224,  243,  291,  397,  462,  492. 
-ammonia,  133,  401,  492. 
Acetab,  133,  177,  251 
AceUmJde,  laa,  123. 

Mercury,  123. 
AretHminohydrazobenzene,  p-,  378. 
*AcctanilidG,  369,  372,  439. 

Telocity  oC  formation  of,  369. 
Aetat«,  Aluminium,  417. 
_       .Ammonium,  498. 
•      Barium,  164. 

Calcium,  127,  140,  390. 
Ethyl,  103,  251,  292,  296. 
Potassium,  198,  299. 
Sodium,  406. 
Acetates,  107,  108 

Testo  for,  108. 
Acetic  acid,  53.  58,  01,  104,  106-108, 
139,  153,  164,  iSo,  192,  212,  218, 
240.  251,  257,  291-293,  296,  369, 
376,  522. 
Ortho-,  107. 
anhydride,  115,  134,301,406. 
Aceto-acet  aldehyde,  350. 
-acetic  acid,  £S3,  3qi. 
eater,  391-394,  29&-300,  491,  492, 
503,604. 
copper  salt,  304. 
synthesis,  293,  294. 
Acetone,  53,  58,  59,  127,  130,  139,  140, 
146,  147.  1.53.  1.W,  169,  173,  178, 
180,  251,  292,  302.  303.  324,  350. 
•dicarboxylic  acid,  296,  297. 


Acetonitrile,  98, 
Aoetonuria,  140. 
Acetonvlacetone,  261,  394,  500. 
Acetophenotie,  390, 405. 
Acetothicnonc.      See    a-thUnytmethyU 

ketone. 
Acetoxime,  140. 
Acetylacetone,  ago,  351,  299. 

aluminium  salt,  251. 

copper  salt,  251. 
Acetyl-aminoniesitylenc,  444. 

chloride,    114,    250,    291,  298,    316, 
390,  501 

-ciimaric  acid,  437. 

-dibenzoylmethane,  302. 

-mesidine,  445. 

-phenetidine.     See  jAenacHtn. 

-t-toluidine,  371 
Acetylene,  22,  151-153,  154,  155,  166, 
169.  175.  180,  309,  350. 

bromide.  l.W 

Calcium,  164 

Copper,  1.52,  154, 

Silver,  153,  207. 

-dicarimxylic  acid,  206, 207. 
Acid  anhydrides,  115,  121.  134.  338. 

azides.  134,  324. 

chlorides,   114,   115,   116,   121,   128, 
0I7. 

decomposition,  292-294. 

hrdrazides,  114,  324. 
Acidn.  i-3,  213. 

Afiy,  224. 

J>*,  224. 

Aldehvdic,  290. 

Amic,'l92 

Amino-,  242-247. 
a-,  243. 
^-,244. 

S39 


^^^^53^^^^^^^^^^^     tKDEX.          ^^^^^^^^H 

1 

^^M          Acids,  AiiiiiicK,  f,  3i4. 

1 

"Aclive"  ttxvBiti,  390,  4S2- 

^H 

^H            -benzoic,  ■!:»),  no. 

AdipnU,  Calcium,  311,  .342. 

^^^1 

^^P              Aromntir  (iiliydnwy-.  134. 

Adipir  neid,  i£9.  478. 

^^H 

^H                  moaobvdmxy-.  430-433. 

Afliuhy,  U1>. 

^^^1 

^H                    crihvdroxy-,  431,  43.V 

.^ir-tfjndiiiNcr,  24. 

^^^1 

^^M              r-Brotno-,  225. 
^H              Chloroaoctic.  2(3. 

Aiininc,  243.  346. 

^^^1 

iiitrUc,  243. 

^^H 

^H              C,Ht,0,.    H<T  Irt/ly  actdt. 

.\(liliii'  iirid,  -17ft. 

^^H 

^H              DioRiiiio-,  217. 

-Vlbuiiiin,  :M!3,  510. 

^^^1 

^H              l>iUsic,  119-123. 

Ke&;  524. 

^^H 

^H                    hydrox  V-,  22^34 1 . 

SlTrk-.  .^25. 

^^^1 

^m              Fatty,  ve;  loi-itj,  127,  138, 1«3. 

Minclr-,  .W1. 

^^^1 

^^B                HtJiierti  Ix-iixoTc.  4211. 

^H                    -eiibplicuied,  3ii-ai6,242. 

MoWiilnr  uMgtil  of,  SI. 

^^H 

Senini-.  511,  524. 

^^^H 

^^B                    aiil;>)iunic.  424. 

.4lbiiLiiiimlp.  531.  .'>24. 

^^H 

^H                Hcptnriic,  lAi.  205. 

Alliiiiiiiii.ili^.  Ctjppi-r.  ri23. 

^^^ 

^m'              H<.-\nnic.  IS5-  203.  261.  267. 

Albumitis.  2J2.  246,  247,  281,310 

435,1 

^B               ■i-MydioKy.2I7.21S. 

-1.3li.  401,  520-526. 

^H              ^-H]r<lroxv-,2I». 

Arid.     Jh'i-  .'(y'lfu'iin. 

■ 

^H              r-Hydroxv-,  210,  aaj-aas. 
^H                9-H.vdnMv.,  210. 

'."ompil:il>l'',  524. 

^^J 

IJcnntnrvd,  5>3,  S24. 
DrnAtunnion  of,  .>22. 

^^^H 

^^M              Kptanic.  243,  390>397. 

^^^1 

^H                MaDobaaic  hvdmxv-.  2I(V'223. 

Nreiyc  or  Inic,  510,  .'t24,  S3H,  X 

T^^B 

^^1                    itnKat.iiraiHl,  1(>i-li>7. 

NuL-U-o-.  ji21,si5,.^l. 

1 

^^1                Niir<it>i'[i£rii('  4X1. 

tSHlCsor  iiuck-o-,  525. 

m 

^^1                PcntoTiii:',  2'>'i 

Tm1»  for.  523. 

■ 

^^H                PI»-ii(iI.ii>l|>liTijm',  424. 

Alliuniianiils,  .''•20.  .'i24.  336. 

■ 

^H               PIttluilic,  :^.S7. 

AlbuiiiOBVv,  .'24.  535. 

I 

^H                l>olvl)aei«-,  1.S8-210,  419^23. 

Ak-ohoUtvf.     fw  alktandc,  m^aUie,    | 

^B                    hVdn.^Kv.  241,  242. 

Alrohol,  Di^RAtuivlinn  of,  &7. 

^H                raciiilo  ,  .W. 

duty.  57. 

^H                I'vTt'lini'-iliriirimxytii-.  101,  lO.'i. 

Sjxiitic  |tm^ii>'  o(  wiiuiiona  of. 

50. 

^^1                    •iiiiitio.'HHiiiyylic.  491 .  49J.  494. 

^^H                Qtdnoliiif-t.irl  loxvlii-  iind*.  S08. 

Alcutiutic  put.-LHh.  141. 
.■Mcuhots.  AruriiiU'i'.  ;iun,  363. 

^H              t>!ttiinitt'<l  dibasic,  1H8-201 

^H           stR-iiciii  iir,  113 

r,H„..- OH,  49-66.  141,  178 

^^ 

^M              S»tii<titMU-d.2]l  247. 

C<>iii>iitu(ion  of.  49'5ii  T3. 

^^^1 

^^H              iJulph'-ibcnKtilc,  i'2Si. 

VH\i\  diit      Set-  gfvmf<. 

^^H 

^^H               Tnnnir,     S«^  tni,nint. 

Hcxuloilrii'.  1S3,  181. 
It:iimcn*rn  of,  .11,  52. 

^^^H 

^H              Tanorir,  22g  241. 

^^H 

^H               Trtratiiwic.  200.  2IU. 

NfinicnH.itiiiv  of,  ,SI.  52. 

^^H 

^H               Tribiuui!.  208.  209. 

Peiilahydnc.  1t*3,  1S4. 

^^H 

^H               Tottiic.  3K7 

Plivsii-iil  riro|K-ni**  o(,  .W 

^^ 

^^1               t'D-vniiirittt-i),  40(i. 

I'otvlivilrir,  17fl-IS4 

^B^            a?-,  2tS 

rniuiin,  51.  SS.  59.  102.  123 

^^H 

Stinndjirv,  51,  5S.  liQ,  12rt.  130 

^^^V          diku>ie,  201-207 

Tertiurv.  S".  BO,  Uli,  117,  )30. 

Ut, 

^              whh  two  do II UU;  l)ond.->,  167. 

35S.  3fil 

^H                Xvit*'.  3N7. 

T<'lfrthvdni>,  183 

^H            Add-iir>fidci.  32X 

Trihvdrip.  1711-1S3. 

^^H             Aroiiilie  Iicid.  ^01) 

CuttUimlwl.  (."is  ItMJ.  4^. 

^H            Arr<i)i'iii.l.i!l.t&S.i8i,2IH).4!ll,.W.'l,505. 

Aldi-livdn  ncid  «i1phitp»,  ijg,  168. 
alcohols.  2.S4-289. 

^H               -Kcphd.  t6g.  2tin. 

^^1                •aiiiiiiUTii:i.  t68.  4U1. 

-ppsin.  13.5.  I.'W. 

^^1                  -iiiiilinr. 

Aldclivdrs.  115  138.151.153,174, 

ITB, 

^^1            AcrutH-,  ]6t,  207 

217.  323.  388  300- 

^1           Arrvlic  arid.  I5U,  101,  163,  I6»,  212, 

Tn-O,  U>w,  13li.  137. 

^H                    223, 244. 

Viisxturt.U>d,  1C8.  100. 

J 

1 

^^^^^^^^^^y                                      ^^^P               53t           ■ 

L        Afciehydic  aeid«,  2fl0. 

Aminfei,  .Action  of  nitraus  acid  va,  84,            ^| 

^^L^ldimcK, :»(). 

^^M 

^^KUdo-rom pounds,  301. 

C'otiipU-x  iudu  of,  81.                              ^^^H 

^■^tdohexo«?s.  2.15,  2S7. 

Iwiitipristn  of.  82.                                       ^^^H 

Alclnl,  135,  136.  lOS,  223. 

Nouii-iii'laTun*  of.  Ii2.                                        ^H 

coiulfn^ititin.  i^,  2IMJ,  201. 

Prii(i:ir\,  81,  85,  S3.  99,    100,   123,        ^^1 

Aliit)[K-[HrjHcs,  270. 

3Ei-jt4.  31R,  321.  324,  32a.                ^^M 

Alil>)w-^,  2S4.  355,  2fi7. 

i^eaiKhiry,  fS,  84,  83,  90,  321.                ^^H 

AldoxitTiw.  13(1,  131,. 101-393. 

.Srpiiniiion  of.  S3,  S<5.                             ^^^H 

Alipltniic  coDipQ)indi<,  35. 
Aliximn.  .JRI-  S.'., 

Ttrtino-.  83.  i^,  S-l.  85.  90.                     ^^H 

Ti-il  for  jirinia^',  9».                                  ^^^H 
Ammaiio,  3U1,  36&-3T6,  305.                               ■ 

di-ll-e'Hl^,  -1*1, 

Alknldifl-wapi-iiK,  (leiiprul,  ."11.1, 

Phiourv.  3W-37I.                                      ^^H 

Alkalotilts  31.3,  514-519. 

S'condiin-.  37 1 .  373.                                 ^^^H 

Antitiote  (or,  5l.'5, 

Ten  inn-,  :f72-37 1 ,                                  ^^^H 

Rxtnurtiod  (mm  p'-antaoT,  fil3,  216. 

G.abribl's  bvulhcaU  of  urtiiiary,  421.              ^| 

i          Alkidcs,  Mrinllir.  M, 

-122.                                                             ^M 

1         Alkohtilos.  Mcmllic.  iit.  W.  101,  312, 

Amiiig-acclnl,  289.                                         ^^^H 

1                  3tfl.  317.  310,  3Cfi. 

-fu-c-laUkliydc  289.                                 ^^H 

1           Alkyl-nnimr..  8l-»8.  131. 

-lu-iti  c-fllcr^,  21-1.                                             ^^^^^1 

ttnui  1*,  3". 

halidf-.  68-71. 9S.  1 11, 113,  Ifi",312. 

-aeidM,  212-217                                           ^^H 

^^H 

-hj'JruEiiie'i.  Ml,  S7. 

?-.  244.                                                      ^^M 

inntEm'KJiiiiiliiiJidPH.gA,  11«,  1311,31)7. 

^^H 

nitrilc*.  »S,  89. 

.iddiliydw.  2*19,                                             V 

-mirolic  aHdfl.  90.  91. 

-Hzo-licnKcnL-.  4Ct.  493,  415,4ifl,>llK,               H 

-phimjiliine  oxidft,',  92,  03. 

419.                                                                    ■ 

■  phoKptiinii^  nrid!!.  93. 

-fdiupfluniln.  -till,  -102.                                    H 

^m       .«iilptiinic  uc-id*,  80. 

4)«rkitunc  nrid.  3.30,                                         ^M 

^H      -<nilpl>«rit<-  n.'id«.  7!!.  Ml.  314. 

..hrntrnrKiiLnhoiiir'     will,     }>•.      ixt              ^| 

^^^      -itiilptionio  elilori'lpn,  mo. 

tulj^anitte  tifiil.                                              ^M 

1          AlUyh'ti'"".     S11!  iib'lSnet. 

-iMViUiie   arid,    0-.     Sv  ont/tntnilie              ^| 

1          AllnntnJnp.  339,  330. 

Hflrf.                                                                             ^^^H 

1          A'len*.  l.'j.l. 

-lH>ninvirtiritiir  KDid,  D-,  5011.                     ^^^H 

I AUm  ■tiiimiiiir  nrid,  4Wi. 

-lari.vric  nriil,  j-,  244.                                ^^^^| 

^KAIloxitn.  3id.  319.  33^. 

-i'~miiiiiii»ltli-livil'-,  "-,  .^m,                          ^^^^1 

^^pAllo-xaniiiir,  3tt).  :V.V\ 

-vimiHiiiii'  lu-id,  0-,  .VIS.                               ^^^^1 

^"^AJlvl  :.lr.>l...l.  1.".  I.-K«.  ISO.  160,  16S, 

•vM}iiipi>uiids,  I'olv-,  -ItJMlfl.                     ^^^^1 

f              '  17ii.  17y.  180.  i8t.  tS5. 

-l>1iirnrk-  :i<-i.!.  «-,  24)!,  hS3,  .>27.               ^^H 

1            -fttiilini>,  r>i>.>. 

.B^ianidiiif,  327.                                          ^^^H 

1              bromide,  158.  17.%  17<J. 

■IcrKincM,  ■J>i<}.                                                     ^M 

L tliloride,  l."i",  158. 

-iiiai«Hic  itcid,  0-,  TilO.                               ^^^H 

^K      iwliilr.  XaS,  158.  I(»l.  lUl,  lai,  ifli. 

-iiuphlliAleite.  443,  '|.|4. 474.                     ^^^1 

^^f      i»thiorl,-;in:lI<-.  314. 

.iiiiphlluil  ri  :-ii,  47(1.                                  ^^H 

^^^      -pvridiiiL-,  It'.  4y2. 

-iiilroiiii^iulrni-.  444.                                 ^^^H 

1              m]lpl^>il*'>  l^fl 

•iioDotr  ,vid  <0},  ICG.                                       ^M 

1              lliiiH'VAiiiitr,  314. 

-phcDut.  0-.  4211.                                           ^^^^1 

[          Allvkno.  151.  IM.  '5.-), 

i-,37li.  ll-.\  I27.43'>-                            ^^M 
•pfvi-nyl-hvdrovylniiiiiM.',  ;>■,  413.                ^^^^| 

Almond',  Itiltpr,  3i)9,  jio. 
AliDTviniiiin  rhloridr, 3$2. 

-;>-nr('lntiiiru)plu?ii\tiimin«,  ^,378.             ^H 

AmlH-t,  194. 

•pwipionie  acid, ,?-,  i44.                                    H 

k           Amio  lu-ida,  102. 

AmtiU'*.  in  ii3,  312.  SO. 

-tliicip)ii-n.     S^-  ttiuijihmine.                                ^M 

.Ammonitim  hmiox.Qiiatermir),  ji2.3T4,             ^| 

Amidiiic*,  12;i. 

^^H 

Alilidivrldnridrx,  123. 

AinyKil'diri,  }ia.  SSf.                                     ^^H 

'■\riiii!ni,"'-(.in. 

n-,\mvl  nlrohol.  I>imiir\ .  .'il.  iS,  60.          ^^^H 

A  mid' >x  !»>•'»,  124. 

broniHk',  i*i-iiiiur\,  7'i.                            ^^^H 

Amion-,  Alkyl-,  81-88.  324. 

chloride,  i'riiiiiir)',  7".                               ^^^^| 

INDEX. 


n-Amyl  iodMc,  Priinarv,  70. 
ARiyl'nlcoholii,  J4,  353'. 

mlriU-.  24y.  3i>S, 

•riulphnte,  Itanum,  72 

•milpliiint'  Arid.  N5 
n-Aiii>U-nr,  H2,  H3 
Amvlciie^.  144,  143.  147 
Ainvkiid.  2B7,  28S 
Aiin.-ath.^ti.-8.  171,  172.  M7. 
Aiialvm.  {jiiAtilJilivc,  3-5 

Qiiftniitalivf.  &-IZ 
AnKiflti- Brill,  ini. 

An)Hilml<-4.  Aciil    115.  121,  134.  338 
Anln'riro-ba8if«.  429. 
Anilide,  Polaaaiiitn.  571, 

AriitiiiiM.  raw. 

Aailiiti?.  2A8,  2«1.  288.  3m.  3(t8.  309. 
370.  371-373.  375-377.  379-3S3, 
3«B.  40I-J'»:i.  112,  415,  -lie,  42$, 
AM),  4ii.S,  4(H>.  ."JHfl. 

<licJtli>r«iici?tHl?.  402 

dvp*  53.  2ii;i.  ml.  am,  4U. 

KU-i'lnireijiKUOd.  u(.  370. 

lij  dforhbridff    371-373.   305,    401. 
403 

nUrair,  395 

Tftrt*  for,  370. 

trirhlcHYini<Pttilc,  402. 

-j'ellnw,  41S 
AniniM.  113 
Ani*»niliit>>.  3!>3,  .101. 
Anwok. 3ft4 

•diaujnium  r^'anido.  400. 

-«uli>h<iiiir  wld.  387. 
Aiii*>  l|ihfD>  1-kcloue.  303. 

-kfitoxiiiir,  303 
ANacniiTZ  470. 
Aullinwco*,  470.  -478-485. 

«I,  35*.  179.  IS.) 
Anrhrnnilir  ncu],  4.10^    ..Vi,  433,  4)9, 

440.  4lft.  511. 
Anlhraiiol.  48.1. 
Atil)ir»i|iiiiiuiii',  -1S0-I'!,» 

-iiionwiil|ilii'iint'-.  Smiiiim,  481. 
AnlilVhrinf      Sn-  acrianiiide. 
AnlimouyiH-aiaiiicthyl,  04 
.Atilipvriti'',  .MW,  501 
Aiiti»ptii".,  171.  :i«2,  424,  151. 
Amhimw,  159,  361,  363,  26S,  270-272, 

2S2 
An(l>it«l.  i8j.  1S4,  250.  2(i2. 
ArotMinir  nrid,  2»W 
Ar)[iRinc,  337.  32"^ 
AfK<'1.  231. 
AHMnrxOHU,  3IA. 
ArciRitlir  nk-ofaob,  300,  ,163. 


AmmaliQ  aminM,  301,  3£A-37<>,  305. 

romprtuiulfl,  35,  3.18. 
AniencMi4«Ei-iir,  ^t,  392. 
Antilles,  93, 

Arainobrnzjenp,  381 ,  .1S2. 
Areoniuiu  \mm».  Quatemaiy,  9Si 
AnificLiU  cAmpbor,  453. 

niuxk,  4 It. 
"AM.-ptol."421, 
Ax|>arui;iii'<>,  146.  21:2. 
Aa^mrltc  ucid.  146.  522,  £27 
.^"j'mftictrio  fiilmgpii  ntom,  374,  376. 

farlKin  aloni,  O3,  65, 

till  atom,  M 
.Mropa  Mtitdnnnn.  510. 
.Atropine,  516,  fil7. 
ArwBHft.  4.W. 
.AvouAOHo's  kvpotbcsu  or  Imw,  13,  i<^ 

17. 
Aielaic  &cid.  I4>.^.  189 
AtideM,  Acid,  114,  '.i'ii. 

.^Xt^•hr^tX»t^r.  377,  .T.80-3S2,  4H1. 

-ilvmi.4ie-410 
Asoxvbpni^ne.  376.  377,  379,  380. 
Azulminic  ncid,  300 

B 

Bacillus  (icidi  iievolactiei,  240. 
iiai~li-ri»,  270 

UADIi<':tlK  A.MLIS'-  L'ND  SoDA-PADtUKi 

51 2 
VON-  B-icvEK.  142, 150.  100,  207.  261, 
3CM,  311,316,  300,  410,458,  500, 

5m. 

VON  Uaktkh'h  rengenc,  141,  34-1,  ZS&. 

4CKi.  4S(i.  4(18. 

rynthrxii  of  dibaxir  vidit,  207. 

Icn^ion  ihrory,  150,  100,  341,  342, 
JlaUnti)  of  !Vni.  384 

Tolu,  31.3.  384. 
Bart>itiirii'  ivoid.  330 
lliuu^,  Wji;clal>|p,  .514 . 
Balm »XN  and  .St-Romuit's  bcnzoyl*- 

tioii  iflL-lhod.  38A. 
van  lI«i:M)tAi'KH,  56. 
Bbck«a\?<    tmnHformatlon,  tjt,  160, 

313,303, 
Bwr,  65 

IMii-ni)lic  iicid,  21(1. 
I)ciiRn.[-nniliiic,  300. 

clilnrido.  38S,  too,  408.  103. 
BenzaJdcliyrio,  310,  3fi3.  .174,  370,  383. 

3S5.  388-590,  405,  40tt,  408,  «" 

4«S. 
BenMldinic  livdrochloride,  380. 
BcDZiddiiximrr.  .4iiii-,  ;ii>l-303. 
5yn-,  301-303. 


IHDEX. 


JS3 


Benuinid«,  384, 386, 387. 

Silver,  3S6. 
Bfnxnnilidr-.  3Sa. 
Ren xani side,  394. 

BcnEcuc,  22.   153.  3»S,  339.  349-351. 
35» -JSS.  358.  3fil,  3B2,  -Vil.  3S2. 
38^4.  3SS-3&1,  -lOS,  -114.  -Il-S  119. 
461-J63,  4S1,  4W.  WO,  502. 
Ci-iit  ric  foniiulji  for,  3-l(>. 
Constitution  nf,  :ti:i'3l»L 
•4Uiixi)-li}'ilriisi<l(!.  Sypt-,  400,  401 . 
-diasoniuni   chloride.   305,  30(1-399, 

40i-4n:i,  4ir.4is.  :-*.U- 

hv-droxicli-.  379.  39b,  400,  401. 

nltrttti',  395. 

feulphalr,  307.  3ns. 

vulpliviiic  lu-id.  418,  435. 
dUul'c^lituiioii-protliicM.  3-14. 
diBiilphrinir  nriil,  »i-,  408,  424. 

;*-,  lltS 
Equivalence  of  six  tiydrogcti  atonw 

u(.34.T.432.  433. 
hfxa-ljrtKiilde.  409. 

-rhloridr.  409 
tti<riio«ulj»uiutioD-pn>duct«,  344> 
•nuvlirua,  338.  348. 

-«iilplir>natc.  I'ot&wliim,  361. 

ftxIium.3S3 
-5ulptiotil(>  m-id.  340>  307. 
ehloriilr.  3(13. 
Benxhydrfl.  3IK) 
DenJMin*,  377.  461.  4rS. 
nii!|ilinli-,  377. 
-imnufwrmHtion,  377, 4S2. 

-dibxiT7i«,  Amphi-,  468. 
.4>iit-,  4l»8 
Sjfn-,  488. 
Bpnzilioarid,4C9. 
B*ii/iiic.  :i9, 

Dariimini'-.  Cnlritiin,  343,  363.  390. 
Kihyl,  3*5 
Fotasitiuin.  380. 
Sodium,  384. 
Bcnxotc  ><-id,  24.S.  313,  350,  360,  363. 
383.  384    3»W-3»7,  3BtJ,  405,  408, 
42(5.  432. 4«l.  466,  482. 
tiolitbilitv  curve  of,  385. 
•Dhyilriili-.  3S<i. 
iminwrthcr.  3}i6. 
Wtuuin,  4t)H- 

IBi-nKKiiirilr.  375.  383.  387   391.  308. 
•plmiuiir.  371.  390.  391.  402 
-purpuriiM.      ijcc  dije*.    IftntQpurpu- 
rin 
•quinone.  400,  41a.  413,  414,  436, 
426,  447,  4<i4,  476. 
I' 


Benio-qninone  dicixitn«,  412. 
DHiiiovinie.  413,  437. 

-iriclilondi'.  SS3. 408. 
Bcniovl-bpii/oir  arid,  n-,  481. 

cfJoridc.  3rtfi.  .184-386.  390, 301. 

Ii  vdroKvii  [leroxidc,  390. 
Itcittinnftcopv,  300. 
llon.yl  Jcohol,  360, 363, 383, 388;  380. 

-ftmin*  366, 375. 

bromid*.  SiiO. 

chl(jrid«-,  358-360, 303, 306,  375,  387, 
408.  44)3.  4G7. 

rvBiiidt.-.  i^T. 

iodide.  360,300. 

'phi-nylnll,i'liimthyliunmoiiium     hr- 
droxidc.  374. 
IV  n  J!  V  lidpni'phci  1  vllij'd  Twy  Uiniiie,379. 
Behtiielot.  2.  36,  36, 117,  261. 
Behthci-ot'ii  law,  30. 

K^-nthioiiK  (if  iiti>lluu)D,  30. 
licit XKI. !(->«.  I.  2. 
Ufiaini-.  145,  246,  514. 
BK\f.lllNrK,  i-il, 

l)iniol<Yiil»r  mictions.  83.  no,  331. 
Dismutltint's,  Trrtiary,  04. 

H\irv.-i       ^W  </i<iK«. 

UioT,  61 

BiKmiirok-hmwn .       $<««      frwiMtHoaso- 

Bitter  printriplwi,  34>3. 

liiniTt.  ill,  523. 
-rcwtioti,  533.  525. 

Dliuline  k*'Ia'>i"^.  '83. 

HU»xl.  Tr-ii  r..r.  526. 

BtiKBBKKN,  391. 

Ik>ilin);-iKiintiippnratue.McCbT's^,21. 
DetorrnLnatiun  of,  33 
Rai<inf{  of,  16,  17,  30,  3i. 

ROKDT,  176. 

Rompo  etimphor.    Sec  btmwcL 

Bomeol.  451.  464,  4SS>  '(58 

Boniyl  dduridr.  4.^6. 

BoTus's  Inw,  111. 

Briuicbcd  carbon  chains,  48. 

Bntudv,  55. 

BrsHuidic  ooid,  165,  210. 

Brauvtii-  fu-id,  iSO. 

Bkkijt,  459.  4iiO. 

Bromlaunf,  90  323. 

Bnmio-inM-ivrideni!,  158^ 

-ncids.  r- '.  225. 

-amldfs,  312,  313 

'tinllimqu inline.  4.SI. 

-i>diicn«iiul phonic  ncidx,  424,  441. 

-bfuivi'ic  A4-id,  ra-,  432. 
0-.  430. 

-ImiiivI  bramtd^,  o-,  4S0. 

.«th)  UiiiiDt-,  422. 


^m        5$4                                                    INDEX.                                            ^^^^M 

^^M        Brnmofiimftrir  nrid.  20(1. 

Ounphanlr-  lu-Id,  455,  459.                  ^^H 

^^^^v     -ifiDbulyric  ncid,  163. 

Qiimjihenc,  454,  -IfiS.                           ^^H 
hydrochloriclc,  45-1,                            ^^^| 

^^^B    -malotc  Bctd,  200. 

^^^V        uibydride,  20G . 

Cat  It  pi  lull' uic  »cid,  4JJ.S.                          ^^^| 

^^V           -tnolonic  ncid,  225. 

nitrilL-,  455.                                             1 

^^H            -nRphllia]<>n'^,  a-,  473. 

Cnniphnr.  4.12-4M,  455,  458-460.        1 

^H            -nit  rnhcn zoic  scidv.  432. 

Anifii-inl.  4.'S3,                                     ^^fl 

^^H            •phcnnri  llirene.  -ffS. 

oximi?,  4.U.                                          ^^H 

^^B            -[ilitliulic  aiiliydridt!.  4SI. 

^ulphnnic  and,  d-,  37fi.                  ^^H 
Otmriruiric  iK-id,  4A5,  450-                    ^^H 

^^H            -propiimir  itriil.  a-,  233. 

^H                 isobuiyl  cfiKT,  223. 

CWnphtimtii  c  nrid,.  LIS,  459.               ^^^ 

^H            -prop.vli^iie,  J?-,  l.VS. 
^H             -vtdtrnc  avid,  f,  213. 

L'ainphor*,  3.VI,  452,  4Tii,  455-469.            1 
CViidk-B,  "Jjleariw,"  110.                      ^J 

^H         Bromofonn,  173. 

Cwu.'-suK&r.    isw  «um*M.                   ^^H 

^H         BniHnv.  MO 

E«timnlinn  of,  377.                            ^^H 

^H         BRUHi..:iOI. 

Manufn^^'tUTP  of,  270.                         ^^H 

^H          IlRiiVN,  LonitT  DB,  on.  208. 

CnouK^houir.  155.                                    ^^H 

^H          Hiic'iiXKK,  KorAiiii,  2Sn, 

Capric  and.  104.  1SS.  IIM,  2Uit.           ^^ 

^1          Ik-Kscx.  93.  .'123. 

Cnproic  .trid.  104.  108,522.                         1 

^H          BuUuic,  38.  %).  4J.  -17. 

Cjiprt'tir  acid.  llH.                                 ^^^1 

^H             -IxTsiinirboxvli*:  avid,  uihi^jw*-,  200, 

('Hruiia-1, 274.                                      ^^H 

^H 

CWininntc,  .\nimotiiuin,  333.             ^^H 

^H             -tRlracArboxyUc    Mfid,    omfio/',  200, 

Cidciutn,  32-1,                                          ^^H 

^K^         310. 

CftrliMfnic  ncid.  323,  324.                      ^^| 

^^^^^^TTTT-KIIOW,  I-I7. 

rHond<>,  3K4                                      ^^H 

^^^■Stitlfr.           IIIU 

CuTliniiiidii.     8('i'  tjrva.                         ^^^| 

^^^^'"  Hurler  01  mitiiiitiiiv,"  313. 

C»rliR2ol<>.  479,  519.                               ^^H 

^M        Butyl. »». 

(.'arbinol,  SI.                                           ^^^| 

^H             -an-tfutci-tic  »>ter,  294. 

l>itfthy].  51,60.                                  ^H 

^H             -nrctyli'iii-,  151. 

l>inii-thvU-ihyI.  51, 60.                    ^^| 

^^U             lilrnhol,  ln»-,  fil,  SQ. 

iHtbutyl,  Kl,  60.                                 ^^H 

^^U                   NomiAl  urinmry,  51,  ^,  $9- 
^^B                     My^oimary,  &i,  59, 

Iw>propvl,  51.                                     ^^H 

M-.nhyIi^thyl,  62                              ^^1 

^H         H-HiUvl  iimin".  SS. 

Met  hylisripTonyl,  51,  6b.                     ^^^| 
AictliV  Iproiiv  .  51,  60.                       ^^^1 
n-rnipyt.  52.                                      ^^H 

^^B                 cfiloriili',  PriTrinr\'r  70. 

^H                 brotnidi-.  rrirnary,  70. 

^H                 iodide,  I'hiiury.  Tl>. 

Secoiidarv  biilvl.  ."^1.  Oo-6t.          ^^H 

^^^^^^             rtn-iHidiiry,  1S3. 

Trniiirv  liiiTyl,  .M,6o.                     ^^^| 

^^^^K        -Oicthylncrlir  ncid.     Six  mtiki/t-a- 

Trimrthyl,  5).  so.                             ^^H 

^^^^^P              biU}ltart4ic  aci'l. 

<'jirbobydrikti'b.  254.                              ^^H 

^^^^^  i»-Diilyk-Tii-,  141.  14J,  212. 

Caibuliv  acid.     i?e»;  pkennf.                         V 

^H          HttiyraiuKlo,  123. 

<i1,3Ss,  :tlll,  470.                                       1 

^H         Itulyrnto,  Kthyl,  116,  1!IK 

Csrb&R  Mtam',  Ae>'min«lric,  63,  $fi.          1 

^H         ButsratcM.  Gili^iuni.  KX). 

Priniary,  40.  '                                         1 

^H          BiUyrit!  ndtlfl.  MM.  \m 

Qitatirrinn ,  40.                             ^^J 

^m             arid,  Noniial,  1(14,  i&S.  135,  257. 

S^'tittdary,  40,                               ^^^| 

^H         ButyrnlnctoiH-,  iig,  221. 

TrnninHl,  4(1.                                 ^^^| 

Ttttiary ,  40.                                       1 

^1 

bniid,  Suiuri'  o{  doul>I<:^,  HS-tSO.       J 

^1       Cicodvl.  93. 

cluiiiiK,  10.                                      ^^H 

^H            (hlondi-,  03. 

comiJKiundM,  Niituborof,  9.             ^^^| 

^H            oxid^.  93,  lOS. 

Ilelwtiivii  ol,  .■},  -1.                              ^" 

^^1         OuinvL-mio         Sec  penlameth!/lentdia~ 

Dc'ti-rminiilifiri  of,  5-7. 

^^H 

disul]iliide.  173,  318,  319,  325,  376, 

^H        Cb(To)do.  3:11.  J33-334.  .HH. 

5IIU. 

^^1        Calniiin  i-ubide        8eo  a<etjfU*te,  eai^ 

IHvnIrnrv  of.  23.  98.  15i8.  SIS. 

^^^k 

MolrniU-  <)(.21.22. 

^^L^Cillco-printinK,  lOS 

oxycliluride.     Sec  ctahattyt  chtaritt*. 

1 

^^^^^^^^^^^^f                                                                  535      ■ 

L              CaHion  oxyflulphid^,  313,  31-1,  J19. 

Chloro-4wiutenediA>iK^-&Tiitlt-.  Si/n-.  AOfk  ^^H 
•brnMic  arid,  m-,  383, 416.                 ^^^H 

^^H            ii>l  rahromiilit.  !^^^  Utrahnitiu/turthane. 

0-,  416.  43U.                                       ^^^H 

^^H           teimrlilorjdo.  Hev  lelracliloromttlMiw. 

P-,                                       ^^B 

^H          tctraethvl,  94. 

J]pnxiiiiilri]p.  »-,  400.                           ^^^^H 
-broniotriiii^lUyieiic,  355.                   ^^^H 

^^B          'n-lrnvulenry  of,  23. 

^^1           Trivnlt^iy  of.  4S7. 

•buivric  .ti-iH.  ^,  212.                       ^^^H 

^^F          VajMur  di-nnity  uf.  21. 

■ntfvmi-.  334.                                        ^^H 

CKrboiib  acid.  317. 

-ciirboiiic  L-st«r,  208,  298,  jit,  324,      V 

dcriviiliv«e,  317-327. 

37.>,  %^.                                                     ■ 

t«t«i».3i7.  J'».  320,  324. 

-«tb(.Tv,  185.                                                   fl 

Orllio-,  3211. 

•)wloav«,  130.                                                ■ 

Cttrlionyl  phloriHr.  172,  .'Jn4,  317.  320, 

-methylrac,  172.                                ^^^H 

374,  :wi,3ft0 

-naphthalene-,  (f-,  473.                         ^^^H 

-poiip,  TrBUfor,  132. 
-  livdiiiglobin.  .^2H. 

•nltTAbrnzi-ni-,  ji-,  447.                         ^^^H 

-tixnlir  r^Tcr.  3Fi&                                      ^^^H 

Cnrlivbinuiie  reaction.  90,369. 

-phenol.  0.  425,  420.                        .  ■ ,  ^^H 

»-,  42.'>,  42D.                                    i'^^H 

-piRiin,  t?],  326.                                    ^^H 

Carlivlflniiin'.H.  07-00. 

Coii-Htitiiiinn  ol,  87,  09. 

CAHiim.  9. 

-propiooir  ncid,  a-,  246.                       ^^^^| 

Cueriii,  <^2A. 

-p'oink'iK',  "',  15tl,  157.                    ^^^^| 

Cftlalvi".  10.";.  120,  133.  134,  1G8,  172, 

^-.'i5C,                                               ^^H 

iea,  27«.  :iiis.'K»2.  mit. 

-pto|iyl|ili<'iiyl  c-thrir,  ]^,  499,              ^^^^| 

Cntd-hol.  351),  409.  J^H,  'I*!. 

-Uilui'tii-.  U-,  3fiS.                                    ^H^l 

Cation*,  112. 

p-.  .1^.                                       V 

CAItLEY,  48. 

-tnnict  liyli'Df  bmniidi?,  4M).                      ^| 

Olluloac,  254,  187-289- 

Cliloniforni.  00, 171, 17*.  173,  ZIS,?."!?,         ■ 

Nilriiw  of,  2.SS,  2Sy. 

26'A.  310.  132.                                             ■ 

Ctnitin.  .126,  5)7. 
Uoivl  ulcwliol,  WCt. 

Olilorufoniiiccalt-rK.  ^rmrbon'ictattn.         ^M 

VhW>ti-ii>h\l\-iiniiif,  283.                                    ^M 

Cllain.^  BninoliwJ,  4B. 

Clioliiii-,  iS6,  187,  M4.                                  B 

(.'arlioii.  46. 

Clirci  iiiophoTcH,  316.                                          ^| 

Clow-d  wirbon,  170,338. 

OirvMTic,  1S7,                                                    ^H 

^^L           Noniinl.4(t. 
^H           Open ,  33«. 
Siliron,  94. 

ChryMiuliHiv    Het.'  diamuuaMtlmiMitm.         ^M 

<TtirhfiiiiiTnnir  ai'id,  44*;,  509.                        ^| 

Oinrhona  bark.  .'ilK.                                          ^M 

Dian-iHil.  WocmJ-.  423. 

Ciurtiiiiiijii-,  -)37,  518.                                        ^1 

DB  ClIARDoNSET,  288. 

Ciiirnt.  (,V,,                                                         H 

(SlATTAWAT,  311). 

(■lnn[im,'i)(kh>iJe,  405,  -lOfi.                            ^H 

fbdidoniL-  acid,  3«^.  303. 

C'iiinHmii,-  add,  40ii,  406.                            ^^^| 

C'A«/'V/<»ifuni  rtfijui,  302. 

nlpahol,4lX'>.                                           ^^^1 

Chemim  rv,  Cliusitkutioii  of  oi;g]U)ir,  35. 

Ciind.     Sm-  genttifi^t.                                ^^^^M 

of  *Jli(OB.  94. 

ritrnlf,  CHldiim,  241.                               ^^^H 

CnitVRKt'i,,  110. 

Trii>lhvt.  242.                                         ^^H 

Chitini.'.  iSfl. 

Citrii-  iu-ld,aW.  141,  a4J,  277.  200,510.  ^^B 

ChitoMinirp.  2S9. 

tiinnouilrilc,  21)1).                                            H 

hyilriicUloriilf,  2S9. 

CiCTvmiict*  glalirr,  242.                                            ^| 

Cliionil.     A-i-  tnr/dimnitxtaidihyde. 

p/cjJtTi'inu*,  242,                                            H 

alcohulnt-,  202. 

Ci.Ai»K>''»  coiKldiiintioD-mHliotl,    150,    ■      ^| 

hydrato,  251,  35».  2W),  205. 

2!11,  2fl2,  2'ifi,  300,  a(i3,  a.V).                    ■ 

Clilnranil.     Si*  Utraehlortxpiirumf, 

OasnificAtioii  o(  orf^Anir  rlieniiHtry,  34,  ^^^B 

CUont^e*.  Acid,  114, 115,  1  Ki,  121, 128. 

['Io«:h(  mrbnn  rtuiiu,  179,338.               ^^^| 

Chloro-iicrtoiiP.  HQ,  1$),  isfi. 

('i>ii|rilfi(i«ii,  511,  .523.                               ^^^H 

K           -eldt-hydvs,  130. 

Coulgns,  36,  111,  151,  3$t.  470.              ^^H 

^^H           •nil ivl.iii line,  t;  4S9. 

^^^H 

^^"            -nnilinr,  wi-,  447. 

Ciiriiiiii-.                                                       ^^^^1 

I                          P-.  4f>U, 

[  -             -bcnscnvdiasocyamdc,  Anti-,  400. 

CoeiiAc.                                                       ^^^H 

^^^B  -                                ^^^^^^H 

CoH&genf.SZ&.irf. 

Cj-jinaniitle,  Silver,  315,  326,  327.           ^^^| 

Collie.  3IM. 

Qranatc,  Potaarium.  306.  313.  313.               ■ 

ColiKi\n<:,iQ\,4it»- 

Silver,  313,  320.                                                ■ 

Hiirwhojsvlic  ethyl  twter,  40S. 

(inc)).  AniiDuniuta,  320.                                    ^| 

Collitiincs,  4D1. 

Potassium.  321.  323.  331.                           ■ 

Coll»ai«a,  288. 

Cyanliydriii  svii>l»'r'i«,  130.  217,  'XM,  ^^^H 
221,  223,'22l>,  212,  213,  24t>,  250,  ^^H 

Colloids,  S21- 

^^    Co!oiir-l)(uu.-t.  -IM. 

2BI,  263,  265.  26S,  271,  2K>,  203.  ^^1 

^^ft    CoKHE^.Irivnli'ntnluniiitiiiniutoHi,  Z5L. 
^^r     CombuHiion  funiacv,  6. 

Cyanic  arid,  31 1-313.                                         ^| 

lao-.  31J,  320.                                        ^^H 

Hi-xl  <>(.  3fi. 

i-jiture,  311,  313,  319,  321.             ^^H 

Compounii  ethers.     Sw  (wferji. 

Nonniil,  312.                                    ^^^H 

CoiiipoundH,  IlclcrocycUr,  330. 

ratcK,  312,  316.                               ^^^1 

Hiiliiofvriii;,  338, 

Cyanide-,  Airiiiioiiiiiiu,  309.                        ^^^^| 

Prim  [in-,  52. 

Cuptic,  3UH.                                             ^^^1 

^onnilarv,  52. 

('tiI>rou«,  309.                                           ^^^H 

T(Timry,"52. 

Morcuric,  310.                                          ^^^H 

Condonaulion.  136. 

Poloaaiuu,  30S,  310,  311,  383.             ^^^H 

Condi-iwcr.  Air-,  2-1. 

StlvnT,  308.                                                ^^H 

LiE»iu'ft,  24, 

Cvanides  (See  alfto  nilri/r*},  309,  310,        ^| 

Reflux-.  23,  34. 

fl 

^L   Cooduoiivity,  MiiIpcuIm  i^tric,  35. 

Alkali-.  310.                                         ^^H 

^^1  Cooglomeratv,  34.0,  211. 

AlkoliiK^orth-,  310.                            ^^^H 

^  ConiEo-red.  475. 

Teat  lor,                                               ^^H 

CoiiiiiK-,  49»,  493,  5I-I,  516- 

Cyano-4ict^ic  acid,  192.                            ^^^H 

tiiriruti-,  iw:i. 

-bRHKoin  acid,  !>-,  423.                              ^^^^1 

CiHiiiiin  mnmlatum,  Tild, 

-quinolinpg.  AOS                                        ^^^H 

Coiulanis.  Ii:inii».li<in,  iia,  113,  1(12. 

C^anof;en.  IW).  308,  308,                            ^^H 

uf  the  fatly  acids.  113. 

chlurklo,  313.  .11.^.                                ^^^H 

Const iiutioiial  foFinula',  45,  GO. 

derivativi-v.  308-316.                              ^^^| 

^m     Cnrnrin,  A28. 

Cyanuralr.  Potaisiutii,  310.                       ^^^H 

^^ft    CotAfBIDf,  518. 

HMver.                                                        ^^H 

^   Cotton,  287. 

Cyanurir- acid,  311,  316,  322.              '     ^^^1 

-wool,  2fi«. 

cater.  312.                                              ^^H 

<!otiiitcr-ci«Tcnt,  Prinriplc  of  Ae,  277, 

Insoluble.  Sfecuamtlidt,  ^^^H 
Uo-.     S«>  eyamdide.                           ^^^H 

Cotiplp,  Zirc-conpiT,  37,  144. 
CtLKrr&.     See    1-kif.i^kl    and    Cieait^' 

i-itii>n<,  312,  316,  324.                       ^^H 

tynOuna. 

bromidt',  316.                                            ^^^H 

trwun  of  tiu-tw,  231. 

chloridt^  313,  310.                                ^^^| 

Crcovjtc  fiil.  351.  3ftl,  4T0. 

CvfloViexatie.     Sw  firramfthyteTU.            ^^^H 

Cii-ttijls,  3(U.  363,  r.22, 

CS-iiii-im.  3-13,  354.  387.  iHZ.  453.  IJSS-         ■ 

CrciTdiiic  (iciil,  414, 

459.                                                    ^^M 

^H    t'rotoDnldrhydf.  136,  167, 169. 

^^H 

^^f         •artimoTiin,  401. 

P           Crotomic  arid,  Ifll,  163,  166,  169,  212, 

Itatiim  siTyifflowium,  ."ilB.                              ^^^B 

1                    21K,  223. 

Davy.  .Sih  Mumchkt,  317.                                 H 

1            ('Ti,'*t.<tll<ji<U.  521. 

Dfi'cuiielln'lenedicarboxj'lic  Rcid,  189.            H 

1          Cn'StslUsKtion,  FntctJoiMl,  32. 

IWiinr,  -12.                                                           ^M 

1          CrWial- violet,  464. 

tonyk-m.  M2.                                               ^^M 

1           Ciimnrir  uiriil,  437. 

VE.IUA.S,                                                                       ^^H 

^^^     Cutunxin,  437. 

Pcvxy-caffeiuc,  331,                                    ^^^H 

^^B   ('uniaiiaic  acid,  137. 

-dcnvalivc«,  331.                                 ^^^H 

^^H   Cutn<^«,  3a4. 

Prpirasiniftcr.  Ktkuxk'ii,  19.                   ^^^1 

^^H    Curnrin(>,  510. 

Denatumlion  of  spirit,  S3,  57.                    ^^^| 

^^1    Crimi:H,  247. 

Dcti-niiiuiitioii  »f  [KHiitioD.     Sec  oritn'        ^M 

^^H  Curvn,  Vapour  tension,  2S. 
^^1  Cyamdidc.  311.  310. 

^^^^t 

Developen.  Photographic,  430.                 ^^^H 

^^B  C^ananiidv.  315,  322,  326. 

Dextrin,  286.                                                ^^^M 

^^^^^V                                                                        ^^^P         537        1 

^H     Dextro-rotslion,  61-65. 

Dichlonvacpiic  arid,  212, 213.                ^^^| 

^™       Dcxtros*-.  240. 

-acci(im>,  Syuirnclricnl,  341,  253          ^^^| 

Diabetes.  140,  204. 

-IwnKcnf,  in*.  40S.                                    ^^^| 

|^_       DuiccKiiiciimiiii-,  13d. 

•isociuinotini?.  W8,                                    ^^W 
-napnibalcnc.  477.                                      1 

^H      DiiKx^y),  140.  291. 

^H      L)t^C(.'tylriicdi<:arl>u.xylic  oddf  207, 

2  :  G  -  Dii.-iliaKv  -  8  -  chloropurine.  313.         ■ 

^H      IJincrlvlMiccitiic;  cstvr,  201. 

a-M.                                        1 

^K     UinM<-hv<l<->,  248. 

Dicthyl-earfiinol,  51,  6ow                             ^^U 

^K   Cialkvl-phosphines,  92. 
^P   IMall.vl,  ).>>.■>. 

disiilphidc,  79.                                         ^^H 
clhr>r.     Sc«  fther.                                    ^^^M 

^^      nimnidf.     Spp  Aj/rfrnaitwr. 

ituiloiiiit)-^  192-ltM.                                  ^^H 
o\a)au>.  192.                                                     H 

iii-Ilinminociiproio  ueid,  247. 

^_      Dianiiiit'x.  IM,  i;^}. 

svifL'iiialc,  19'7.                                                  ■ 

^K     I>i»tiiini>-aci<iv,  247. 

-nulplionivlinivtliylmrthane.  Seemf*          ■ 

phoruil.                                                    ^^J 

^H         •azcilirn«-n^,  413,  414,  41ft. 
^B        -phcaoI(L:2:4),430. 

l>ili\clrii'  dntlioto.     S«^;  fflycoU.                ^^^| 

^H        •BtUbcnc, ;»;,  -168. 

biii'iioLt,  400.                                             ^^H 
Dinyilrn-nnlhrnccnc,  480.                           ^^^| 

^^B      Dinim-lfEic,  14$. 

^1      DiruiW.  34,  273,  2$i. 

-SciiKi-no.  455.                                           ^^^1 

^H     Dialotiiii, 'U. 

•(!olIidint'dicnrbox>'lic  catf^,  493:         ^^^| 

^H     Dittfii-iiii-l Ic  c^'iit^r,  247. 

-pyniJEiili-.     t^i'  jMjTiiailitif.                     ^^^| 

^H         •uiiiinu- benzene.  401. 

•pvrmk',  49D.                                             ^^H 

^H              -pomtJuuiKU,  401,  403. 

Dili\droxy-acciouc.  2.V},  260.                  ^^H 

^^1         -)>eti»nif  rliloritli-,  Sytif,  399. 

•ui-id«,  .\r  111  untie,  4S4.                              ^^^| 

^K            hytlrr>xi(li-,  8vn  .  3E)1). 

-llnL)l^l<|uill■>lLl^     t^i^  alitarin.              ^^^| 

^^H            -HuJplioiukto,  Sociiuin,  403. 

-nEohcnEi-Eiraulphonic  acid,  418.           ^^^| 

^^B           -AulphoniL-  nviJ,  />■,  397. 

-beiizctK',  r'l-.  409,  412.                            ^^^1 

0-,  409. -)I2.                                     '^^M 

^B             .4fi/i'-,31Ki. 

P-,  409,  412.                                         ^H 

H              S^n-.  399. 

-nnplitbiilriir  (1:2),  476.                        ^^H 

^V     Diazoniuiu  compounds,  3tjL,  'im.  305- 

-pbenanthrrne.  486.                                ^^^H 

'                    4M. 

•i^riaric  ai-id,  350.                                      V 

1           Dibasic  udda,  4ie-i23. 

I>i-ifi»liKnct'tic  cjiHTj  247.                                ■ 

^K           IUeter'h  synthesis  or,  207 
^M            Saturalnl,  la<i-201. 

-p-phcnolfiul phonic  ncid,  434.                         1 
-purine,  ."WS.                                              1 

^B             UtiRutunttnl,  201  -207. 

Di-iaoprupvl.  44j,  48.                                            ■ 

^^1      DiticnzhvilroxmtiK^  ac-id,  3IJ4>. 

U.k<toTH-«  (1:21,  249,  415.                               _■ 

^H      Hihr-n/yl,  4<>7. 

(1:3). -J4d,  150.                                         ^^ 

^H         -aniini>.  37-'>. 

(L;  4).  21(1,  151.  496,  498,  501.              ^H 

^H     D  bniTiKwir-Kt.ii!  licid,  200. 

Dituiioii,  l.niv  Iff,  U2.                                ^^H 

^H     Dibroiiiv-tH-nitrnc,  m-,  345,  408,  443. 

I>iiiii-t1iv1-iii-rHvlfi)e,  153.                           ^^^1 

^M             »-.  S^tA. 

-ttllcii'i-,  155.'                                             ^^M 

H             P-.  MR. 

-aWuxstti.  »a2.                                           ^^M 

^H          'Iirawidic  acid,  216. 

-tuiiinir,  83,  &6.  373.                                ^^H 

^H          -bulyric  ucid.  166. 

-unuuD-nK>bi'a£i.-nc«ulphoiiio     acid,    ^^V 

^H          -rruc-ic  ndtl,  21Q. 

418.  42.',.                                                    ■ 

^H         -malonio  ««ter,  295. 

-bonxcnp,  4(12,  417.                                        ■ 

^H         -prepanx!  (un),  17.5. 

-ODilimr,  37»-374,  **«,  -102,  417,  463,            1 

^H          -propioriAldc-hyde,  200. 

40(1                                                            M 

hydrorbloride,  418.                             ^^^B 

^H          •propA'IciK',  I5S. 
^H          -pyniJiiii-,  5IS, 

oxidr.                                                ^^H 

-lieiiKtriiu.     See  xylent.                            ^^^M 

^H          -succinic  acid,  104.  305,  207,  226. 

-ethylene  Sym mctriciil,  143.               ^^^| 

^           -tbiopliPH.  .WO. 

I'mtinnictncnl,  142.                           ^^^H 

I}ic(iri>onyt-)>Dnd,  374,  283,  280. 

-Uivlbyliticnaptok-,  t4(>,                        ^^^H 

^_^      Dichlorhydrin.  Svmmclricil,  185,  242. 

-ctliyloarbiiiol,  51,  6^.                            ^^^H 

^H          Uiin^'iiimclrii-'iLl,  18S. 

cLhi^,  75.                                                  ^^^M 

^H     Didilnrojir^tid,  agt,  252. 

-kHQOt,  127,  128.                                   ^^M 

538 


INDEX. 


Dimethyloxalate.  192. 

-phenyl  pyrazolone.    See  anlipyrine. 

-pvridines.     See  lutiditia'. 

-pKosphtnic  acid,  93. 

-pyrone,  304-307. 
hydrochloride,  305. 
picrate,  305 

-succinic  acid,  Symmptrical,  195. 
llnaymmclrical,  105. 

-succinic  acid.  Symmetrical,  501. 

-thiophen.     See  also  Ikioxen. 
aa'-,  ,W0. 
^^'-,501. 
Dinaphthol,  a-,  474, 

?-,  474. 
Di nicotinic  acid,  495. 
Dinitro-benzene,  m-,  414, 415,  447,  448. 
o-,4i4,  415, -t^S- 
p-.  414.  415,  448. 

-<iiphenylili acetylene,  511. 

-ethane,  185,  367,  368. 

-inesityienc,  444. 

-a-naphthol,  475. 
sulphonic  acid,  47.5. 

-phenol  (1:2:4),  447. 
(1:2:6),  414,  W. 

^tilbene,  p-,  468. 

-thiophen,  502. 

-toluene(l:2:fi),450. 
Dioses,  25$,  262,  272-283. 
Dioxindolc,  .509,  .110. 
Dipentene,  454,  455,  457. 

aihydrochloride,  455. 

(ctrabromide,  454. 
Diphenic  acid,  462,  485. 
Diphenyl,  352,  377,  382,  398,  461,  48C. 

-amine,  308,  371,  372. 

-elhylene,  Symnietricjil.  See  sliUnnie. 

-elhtine,  Syninietricnl.     tifn  dibenzijl. 
Unsyminelrical,  4(i2. 

-methane,  462. 

-melhyliimine,  375. 

-Ihiourea.  376. 

-urea,  376. 
Diphen^leiiekctone,  4fi2. 
I>ipi('ohnic  acid,  494. 
Dippcl'e  oil,  488,  498,  504. 
Dipropyl,  45,  48. 

Disortionmlonic  ester.  193,  194,  208, 
Dissociation,     Electrolytic,      111-113, 
278,  279. 

Hvdrolvtic,  110. 
Distillation,  24,  25,  26. 

in  Viicuum,  25,  2G. 

Stciuii,  28.  39,  30. 
Dithiocarbamatc,  Ammonium,  325. 
Divalcncy  of  carbon,  23,  98,  158,  315. 
Divi-divi,  434. 


Dodecane,  39,  43. 
DodecamethylenedicarboxyUc     &  C  i  d, 

189 
Dodecvl,  39. 

VAN  Dorp,  312,  423,  439,  508. 
Double  carbon  bond,  Nature  of,  145, 
150. 

linking.  Test  for,  H2. 
Drewben,  506. 
Dry-cleaning  process,  39. 
DT^/obalnnopB  camphora,  452. 
DulcitoJ,  183,  184,  269. 
Dumas.  2,  7. 
Dutch  liquid,  176. 
Duty  on  alcohol,  57. 
Dyeing,  416,  417,  467,  513. 
Dvea,  53,  263,  416.  464,  511,  512. 

.\niline,  351,365,414. 

Aao-,  416-419. 

Bcnzopurpurin.  475. 

Congo-,  475. 

FararoHaniline.    See  pararosanilines. 

Rosaniline.     See  roaanilines. 

Triphenvlmelhane,  463-467. 

\'egetable,  343. 
Dynamite,  183. 

E. 

Earth-wa.-f,  40. 
Ecgonine,  517. 
Eicosane,  42. 
Elaidic  acid.  163. 

t  ransrorniation,  165. 
Elastin,  .526,  527. 

Electric  conductivity,  Molecular,  35. 
Elcctrolysi.s  apparatus,  Ki'ster's,  232. 
of  potassium  salts  of  kiaonic  acids, 
291. 
Electrolytic  di.s.-jociation,  111-113. 
Elect ro-inagnc lie  rotation,  301. 

-reduction  apparatus,  Tafel'3,  334, 
335. 
of  nitro-compounds,  37S-.3SO. 

pyridine.  493. 
pcheine,  Haker's,  380,  413. 
-synthesis  of  dibasic  and  other  acids, 
196-198. 
ethane,  198. 
Empirical  I'ormulat,  11,  12. 
Emulsin,  310. 
Emulsion,  III. 

Endothcrmic  compounds,  154. 
Engler's  arlificisd  petroleum,  40. 
EnoUcompounds,  299-302. 
Enolization,  301.  302. 
En/ymes,  54,  240,  272,  270-283,  310. 
511. 


INDEX. 


539 


Eooin,  421. 

Kpichlorhydrin,  185,  502. 
Equilibrium,  117. 

Priaciple  of  mobile,  109,  119. 
Erucic  acid,  161,  165,  166,  216. 
Erythritol,  183. 
F.r'ithroxoloti  coea,  517. 
pVterification,  72,  116,  450. 

Theory  of,  117-119. 
Eslprs.  67,71,72,88,89,114,  115-121. 

Orfho-,  101. 

Saponification  of,  72,  119-121,  311. 
Ethane,  38,  39,  42,  44,  144,  154,  175. 

Electro-synthesis  of,  19S, 

-iricarboxylic  ester,  195. 
Ethenylaminophenol,  429. 
Ether,  73-75,  HI,  144,  159,  172,  185. 

IHmethvl,  75. 

Methvlated,  73. 

MpthVlethyl,  73. 
Eihereai  oils.  452-4 &1. 
Ethers,  68,  185,  364. 

Isomerism  of,  76. 

Mixed.  6S,  74. 
Ethvl,  39. 

anetate,  103,  251.  2S2,  296. 

-acetvlene,  1.^1. 

alcohol,  52,  53-57. 171. 172,. 178, 185, 
248,  264,  290,  292,    296,    299, 
317,  324,  325,  399. 
Manufacture  of,  54, 
Test  for,  57,  173. 

-amine,  86,  97,  187,  376,  387. 

-benzene.  352,  354,  359. 

l>enzoate,  386. 

bromide,  68,  70,  72. 

-rarbvlamine,  97,  98. 

chloride,  70,  175. 

c>anidc,  97.  98. 

formate,  350. 

-plvrollic  acid,  217. 

iodide,  70. 

-i.sobutyl,  48. 

-mercaptan,  140. 

-methylacetA-lene,  153. 

niethylelhylmalonale.  193. 

methvlmalonate,  193 

nitrate,  71. 

-nitrolic  acid,  90. 

phenylacetate,  300, 

phosphate,  71. 

phosphite,  69. 

8odionialonate,  422. 

sulphate,  71,  72. 

-sulphate,  TWium,  71. 

sulphide,  79, 

-sulphonic  acid,  79,  80 

-sulphuric  acid,  71,  7a,  73,  74,  144. 


Ethylene,  22,  86,  142,  144,  146,  175, 
177.  223. 

-bronihvdrin,  422. 

bromide,  144,  151, 156, 159, 176, 194, 
340,  422. 

chloride,  146,  175,  176,  179. 

cyanide,  194. 

oxide,  178, 179, 186, 187, 199,  496. 

tetrachloride,  175. 
Ethvlidene  chloride,  128,  146,  151. 
Eugenol,  438, 
Eykiuan's  depressimeter,  19. 

graphic  method,  20. 

F. 

Faraday,  354. 

Fats,  Saponification  of,  109,  121,  163, 

182. 
Synthesis  of,  2. 
Fattv  acids,  99, 101-113,  127,  128,  162, 
182. 

Ionization  constants  of,  113. 
compounds,  35. 
Fehling'h  solution,  232,  233,  255. 
Fermentation,  54,  219,  264,  279-281. 
Alcoholic,  54.  264,  279-281. 
liutvric,  219. 
Lactic,  219. 
Putrefactive.  279. 
Ferro<->anic  acid.  307. 
Ferrocvanide,    Potassium,    309,    310, 

311,  351. 
Fibrinogen,  524. 
Fibroin,  528. 
Fillering-flafik,  31, 
Filtration.  31,33. 
Fire-damp,  36,  37. 
Fischer,  Emil,  228,  244.  247,  254,  267, 

281,331,333.334,422 
FiTTlG.  218. 
FiTTioM  sjnthesis,  352,  358,  461,  473, 

.500. 
Flash-point,  40. 

apparatus  of  -•Vbel,  40. 
Flax,  287. 
Fluoranthene,  487. 
Fluorene,  462. 
Fhiorescem,  421. 
Fluorescence,  421.  518- 
Formaidehvde,  53,  137,  138,  260,  261, 

282,  369 
Formaldoxinie,  138. 
Formalin.  138. 
Formamide.  122. 
Formate,  Ammonium,  309,  310 

Pota.'isnmi,  310 
Formates,  105. 


540    ^^^^^^^^^^^Mx!^^^^^^^^^^^^^^^^ 

Formic  acid.  97, 104-106, 113, 139,  Ifl!), 

GAT-T.,trssAc'K  Un,  16.                      ^^^| 

171,  172,  181,  i8j,  190,  22U.  252, 

Gvraiual.  450.                                         ^^H 

309,311.315. 

Ccnuiirnc.  456.                                  ^^^H 

mt«r.     Scft  tUti^l  formoU. 

(kmniol,  455.  4S6,  45S.                        ^^H 

Formonitnic,    Sm  ht/droct/anic  and. 

Gr.RHARIrT,  2. 

Formom-,  160,  2U1. 

Gr.iiN'KZ.  61. 

FomiiiliP,  Kiiipiriml,  11,  12. 

Glaimtonk  niid  Tkibx'*  liac-coppef 

Molecular.  12. 

couple,  37. 

CoiuKilutUuiiil  or  HltiKlunl,  45.  00. 

Olobiitin,  .i24. 

Fnmiyl  chUiridc.  388. 

Scrum,  524. 

-phcnvlucotiiic.  Ethyl,  300. 

VcfTcialilc-,  524. 

Frm-ciotial  rr>-»UkUiitaUOn,  32, 

c^GlucMiic  ai-id.  165,  267.  273,  274.        < 
d-Gluconolnctonr,  267 

dLfliUation.  27.  38. 

Frnctionftting-columns,  26,  27,  &4. 

Gil iccv-prot rids.  514,  Sil. 

-Bwk,  35. 

d'GlucoMiono,  165.  2^6,  26S. 

FnAVCjiiwoNT.  321. 

d-V,{w»^,  .M,  .11,  2111.  2-12,  2hi,  x64- 

I'nt-  liiikingfi,  08. 

368.  371-274.  27R,  281,  5S3,  2M, 

Freejung- point.    Loft'cring    of,    16-10, 

2S7.  310.430.4S3. 

3(15.  3nfi. 

/-GtucMP.  368.  2.S1 . 

Mnlrculnr  lovrcring  of,  IS. 

Gluromdnt.  175.  310.  130, 43^  483.  SU 

I-'ni£DEI„  180, 

d-Glucowiit;,  2^  267. 

.                   uiid    CRAfra'    synUKMb,   35*.  3S3, 

Glue.     Sec  jjiuftfi- 

^^                0»1,-I73, 501. 

GlutmniDF,  346. 

^^1         FnictOHtnunc,  2. 

Glutiuninic    Add.     i»e«    umino^Mtant 

^H         d-Frucioat,  2M,  2M,  165-168, 271. 2^, 

add. 

^H            2S1. 2s%,  2Kn,  2kr.i. 

Glutaric  acid,  18»,  196, 108,  202,341. 

^H         t-Fruc.t(wc,  381 . 

i)iili>drid«.  IDS. 

^^H          Fru)t-«U£sr.     See  d-Jruchae. 

Glul'-n-priiiriin.  524. 

^^L        Fulimiutr,  Merrurv,  2SH,  J15.  4U. 

Glulln,  527.  .'j2.S. 

^^B            Sitvrr.  315. 

Gtvccraldi-Iivdi*.  15Q-161,  267.                       ■ 

^^H       Fulminaiing  moreury.    Sec  /uimijuiie. 

Glycrratr.  ]'.v-mi.  251). 

^^F               mercury. 

Glyceric  acid,  trg,  290,  291. 

^^^         Futminid  acid,  315. 

Glyc'TiiiJ.i.      Sot-  fltiftrot, 

^^^^KFlimATAt^,  PI)<'IIV).46$. 

Giycm.!,  .'■>l,   Iffll.    no,  168,  <79-»83. 

^^^^■FuRiaric  arid,  101-107.  ^^,  23«,  237, 

184,  185,  187,  259,  605. 

^^^F^  4.-t7. 

GlyceroBo.     .See  d\M^droXj/oMcn«. 

^^V          Kiiiiii«l,  Srpnntlin^-,  30. 

GlvwroKaione.  2.t0 

^^1         Furfornl   or   furfurole.    Se«  /ur/tinil- 

GlVcorull.  216.  344.  MS,  246, 537, 62& 

^m                dthifde. 

^H         FiiKuraldchydv.  263. 24M.  -196.407. 408. 

^H          Furrtinu).  339,  49&-49S. 

copper  Nilt,  24,'i. 
eulpr,  247. 

liydtuclilitridc,  244, 

^^^         FuriumnVittc.  4!>7. 

'Irinicthvl-.  215. 

^^^^H^l'uriuryl  &loohol,  497. 

Clj-««t?n.  2WJ,  2S7. 

^^^^k^urota,  4(17. 

Glycol.  I.'jS.  177- 179. 

^^^Kriwl  oil,  65,  57,  60,  72. 144. 

-chUiitiMlnii,  ITS,  17fl,  «j. 

^^^^^^H 

-cvitnhvdrin,  223. 

^^^^L 

dfclhyf  ether.  178. 

ninniiPlhvl  rtlier,  178. 

^^^KaUckl,  421, 4S9. 

GlycoUaldchvdc,  260 

^^^^^<}alaotaaG,  169,  274,  281,  283. 

GlveoUaw,  Ethvl.  117.  247. 

^m        /-GalnoloM,  381. 

OlvMilIic  arid.  2l2,  ai6-2ic,  225,  248, 

^H         Qakctoni^  noiri.  363,  269. 

265.  290. 

^H         GalUe  ftcid,  410,  434,  435. 

OlvnJIidc.  119,235. 

^H         G«U-nuu,  ViX,  435. 

Glvccl*.  177-171). 

^H         Onrlic,  Oil  of,  160. 

Glyo\.il.  22fij  14S.  350 

^^B         tias-manufiiccuTv.  351. 

Glyiixylic  ncid,  ifo.  205,  SM. 

^H         Gasliic  juice,  525. 

GuLDsrHUlDT,  402. 

^H            aA1Te«KA.>iN,  3d7, 438. 

QoUBE«o,  467. 

^^^^^^H 

^^1 

J 

^^^^                mOBX                                                     S4t 

1 

Gr&p»-flugKr.    Sc  d-gtuoNW, 

B«xjKhIoro-b«n)CDe,  406.                         ■ 

J 

(iraptuc  mcihott.  Etkuan's,  20,  21. 

^thanv,  17S.                                             1 

^^1 

'■Ori-rniiOUp;'  110. 

-txiolaiic,  3S,  4s.                                     ■ 

^^1 

Gmcss,  395. 

-dcfonv,  42. 

V 

Rriohard,  95,  US,  130,  307. 

■hvdric  ■lcDbol»,  1B3, 164,  235,  258, 

^^^ 

Gualucol,  409. 

'2S4, 267.                                            1 

■H 

Uuutidinc,  326,  S27. 

-hydrftpyridine,    Sm  pt'pmdinc.           ^ 

^H 

thioovAnittc,  326,  327. 

•ttydrDxylM!ti«ne,  411, 414. 

^^H 

GuitniDC',  331,  £25. 

-niethyl-bcnxMiv,  153. 

H 

<>um->riitiii^,  202. 

-triajninotriphenylmpthane.           See 

1 

-benzoin,  343,  3S4. 

lTUJlfll/-f-lo/i:(. 

■ 

Cherfy-.  262. 

-mftbylcnr,  338.  3«.  355.  356.               - 

^^1 

GuncotUiD,  183,  288. 

■AiniDc,  137.                                          ■ 
derivtttivm,  342,  344.                        ■ 

H 

H. 

Hnwc,  3H,  42,  4.<>.  47.  48. 344.               ■ 

^H 

1                                    "• 

HoxodinflCB  (HuxabioMw),  25S.                   V 

^^1 

Haber's  elpclro-ipduction  lehemc, 

Mexonic  tunxAs,  333,  3ft3.  2&4.  367. 

^^B 

J80.II3. 

Hexoaea,  355,  258,  263,  >64'>69,  280, 

fl 

Ilu-itiiUiii,  526. 

283,  284.                                                J 

^^B 

lla-niin,  528. 

HpxotrioapK.  255,  283.                                 ■ 

^^1 

}l(Fincig1obin.  524,  $'& 

rt-Bexyl  alcohol,  52,                                     " 

^H 

Httlklm,  Alkvl,  6»-7i,  96,  HI,   143, 

Hi-xylfHi-.  H2. 

V 

167,  312.' 

Urxyl  iodidr.  Normal  Mconduy,  257. 

^^H 

HAloccbiLtion     method     of     Vicron 
MsvEit,  176. 

Hill,  fiioi-r,  272.                                     J 

^^1 

Hippuric  Acid.  34Si  384.                           1 

^H 

Hologun  bfniotc  a«idB,  t2C.. 

Horcu's  appnrahiH  lot  d«ctro-ji%'nthe- 

BiB,    11)7. 

^^B 

-(■nmcni,  S.i!!, 

1 

potnpdunds,  Uiisnlurai«f,  l.ifl. 

VA-V'T  HoPF,  62,  63.  05,  238. 

^k 

deriviiiives,  AromRtir,  3;*-3fi0. 

Tbivirvof  «lereoi»omeriaiu  or,l>2-6S. 

H 

of  iiirtluuw.  171-174. 

Hoi-MANNi  l.V  III, 

^f 

homolocuoi  uf  metliAiic,   174- 

Vapour  dortsity  nppnrotns  of,  16. 

^ 

17«. 

Horiiiw-vt  lie  coinjxjuiidfi,  33S, 

-hvdrint),  185. 

-phlliiiliciM-id.SOe, 

pKcnolfl,  425.  426. 

-phlltalimidcfiOS. 

•subi^itntcd  u-ids,  3ii-3i6,  242. 

HouimIukuub  etrivH,  4 1. 

sulphonip  tAAi,  424, 

Hfttiev.  2U5, 

Holtigenit.  Drteetion  of,  4,  6. 

-«tdnc,  42.1. 

IJi'liTrrilnution  of,  9. 

Hoo<>Kw  Kiti,-p,  312,  423,  43!l,  608. 

llAMMLr,  32(1, 

Howard.  315. 

llAN-rattni.  3U8-400.  465.  491. 

Humu»  subwaoces.  200. 

Hitn)  map.  no. 

Hydnirrylic  nriil,  218,  210.  iij, 

n  nlxT,  111. 

Hvdruxicirs.  Arid.  114,  324. 

Ili^ntinK  nubFtnum  toRctl)<rr,  23,  34- 

HvdrMim;.  327.  502. 

}lnkt  of  coinbii»tion,  3S. 

Alkvl-di-rivaiivw  of,  86,  87. 

HenN-j-  oil.      See  rrtotnte  oil. 

bydmt^^.  n(H. 
l^n-nvl-di-rivHtivM  of,  372. 

HcUunthino.       Sm.>  d\m»Ayian\noato- 

bfn3mr»ul}iiiim-ie  aad. 

Hydrazines.  402-^04. 

HeneicoHin*,  42. 

Uydnuo4)Miwne.  377,  3f*0,  401. 

Henlriaconlane.  39,  4>. 

•iMfiixuTc  m-id,  m-,  4fi2, 

Hi-ptjirnicllnlf  tic,  517. 

Hydrtwnm-^.  133.  256.  2(H.  266,  267. 

Hcptfinc.  42. 

llydro-lienj-amidc.  383. 

•H 

Ht'ploiuc  oc'iAa,  a6l,  20s. 

'In-iixuio,  4<iA. 

Hfptt»t-fl,  )SS.  261,  369. 
n-linptyl  olcohol,  52. 

^■nrbon.'  C'„H.«.„  laTl-l.'iS. 

JionicMi-lftiiiiv-  of  llic  lut-InraiiHl,  30. 

HpptvlMtF,  142. 

Saturated.  36-48.  (16,  175. 

Mcplylic  acid.  104,  266,  393. 

ljn.*nt«nit»Hl.  J  il-l.W,  4<M. 

Hcmii(t-bnm',  .S(l. 

with  luo  duubk  bundu,  1.55. 

Hebirocyclk  coiapounds,  339,  488-504. 
1 

iriplr  boiidx,  151-155. 

^ 

^M     542                                          ^^^^^^^^^^H 

^H         Hydropvnnir  &rt(l.  2A7,  jog,  jio,  311, 

Index  of  refraetion,  35.                   ^^H 

^H                    ^13,  314.  31A.  .tKS. 

ladican,  r>l  1 .                                             1 

^H                  ftDtiduti*.  3U9. 

Indigo,  ftTO,  419,  440,  509-51^                J 

^^1            -luiphthitlfni-iliciirboxylic  ncid,  471. 

•lirown,  512,                                   ^^H 

^^H                  -Utracarljoxylic  eal«r,  471. 

■^utcn,  fil2.                                       ^^H 

^^1             -uuiuone.     S«v  iftiinol. 
^^B         Hydroecn,  Dctcctiot)  uf,  3,  -1, 

•iw],  £12.                                           ^H 

•AiilphoEiic  acid,  SOd.                     ^^H 

^^H              |)r:trTinln&lion  of,  &'?. 

-VAttintc.  ^''13                                          ^^1 

^^B              M[.>l».'('iiLitr  n  eight  of,  13. 

-wlute,  SI3,  £13.                             ^^M 

^H               Niurrnt,  37. 

Indigof/ra  UjM»t</cha,  &\l.                   ^^H 

^^H          Hydnilysiii  of  nilrllng,  99,  IDI. 

linrloria,  fil  1.                                     ^^^^ 

^H          Hvdrolytic  di&soomtioD,  110,  302,  306, 

Indigotin.  S12                                       ^^H 

•sttlphoriir  adds.  512.                    ^^^| 

^^B          Hvdroxv.dcclip  ncid.  SwjffyeoWicaci'rf, 

Indnli-.  50Q,  510,  A19.                           ^^H 

^1            -ncidtt'.  <t-,  217,  218. 

Indophcniii  rvwtion,  flOO.                 ^^^| 

^1                /J'.  2  IS. 

Iiidowl,  &11.                                         ^^1 

^m                r;  210,  aij-aas. 

I  Ilk.  431,                                                 ^^1 

^1                4-.  'J It). 

IniiliQ,  2<35,                                             ^^^1 

^H                  DihiuHio,  225-2-U, 

Itivi'rninn,  164,  274.                                  ^IH 

^H                Monobasic,  210-223. 

Invertnsp,  280  281.                                        1 

^K               Polybimie,  241,  242. 

Ijivorlsu^rar,  2I».  164,  MTt.  274,  278.       J 

^^^K      -Aldphy^lni,  437,  43^. 

Jud<>-t)c,n;!rriu  cli<'tiloride,  30O.                      J 

^^^^H     -«iil4iraquiiione,  4S1 . 

•phenol  425.                                               I 

^^^^      -Aiobeiucnc,  377.  403,  417. 

-propionic   acid,  fi-,  102,  313,  aij,    1 
223.  244.                                                   D 

^^m            -iiensultlchYde,  0-.     See  taHtylatd*- 

^B                   Avde.  ' 

Iodoform,  57, 173,  i74>                              | 

^H                fK,  438. 

(cHt,  173,                                      >           1 

^^^^      -boiuoic  Mid,  ti$-,  432. 

lodo§ul)erizcne,  360,                               ^^J 

^^^^K             D-.     Seo  talieyiit  aeiiL 

lodoxybcDt^'np,  3Mli                          ^^H 

^^B             ;>-,  431,  432,  44A. 

Iciiimt  inti,  111-113.                             ^^H 

^^^^^     •batyrio  acid.  Normal,  135. 

ronslanU,  112.  113,  162.                 ^^H 

^H                /!-,  lUl.  318,223. 

of  faltv  acid^  113                         ^^H 

^M                 Y'.  21»,  224,  ??A. 

Ion.H,  07.  70,  Kl.                                     ^^M 

^^K             •cinnruiiir  lu-iil.  e-,  4.37. 
^^B                 -cuH>oxylic  nritl,  v-,  477. 

Isutin.fiOO,  509.                                     ^^^1 

chloride,  SIO,  211.                            ^^1 

^H             -ethviatniru-,  422. 

Iso-«uiyl)Kival<5r&t«,  116.                  ^^^| 

^H            -dutaric  acid,  j9-,  297. 

^^1             -imbutyritt  itcid,  ;'-.  170,  317. 

^^B             -mcthyUtpnxnu'  lu-id,  o-,  420,  43C. 

-butyl  fileohol,  51 .                          ^^H 

-rnrbinot,  51,  6e,  7SL                    ^^^| 

iodide,  143,  147.                            ^^1 

^^H              -phenyl propionic  nciti,  p-.  436, 

-mil  pli  uric  acid.  14.1. 

^H               •pmpiuiik  Bi-i'l.  <)-.    See  ^clic  a<\d. 

-liiityli'iif,  143.  147. 

^^1                  ^•.     Stt'  hij'irtrnylic  acid. 

-biilyric  ncid.  10^.  IOQ.217,  259.  438i 

^H             •propylenp.  /)■.  158. 

■K-iiiilioniPronic  aeid,  495. 

^^M               -pyniuura,  491. 

-crotonic  acid.  103. 

^^B              -qutmilinc  <3).     See  carboW^/. 

-dibromosucrinic  acid,  204-2(M. 

^^B             ■<pijnntj  nv-s,  .SOA. 

-duuitavtbaii«,  3ft7,                                   , 

^^H               -tolu<'iii?A      Sr'f-  crfAiifji. 

-viii;(-'tioI,  43K.                                      ^^H 

^H         S-H\-dru\v-2.  &Kiicliloropuriup.  333. 
^H         Hv(lro\v)iunii)i\  91],  m.  315.  42tt. 

.m.4lti^A%  '2»l.                                     ^^M 

-nirilinic  nrul,  403.  494,  49S.         ^^H 

^M         HVdn>.tyl.  T-M.  for,  114,  115. 

-nilrilcs.     £^e«-  carbiilumtnes.            ^^^M 

^^H         j-)  vuncvniiiiTiiC.  517. 

•nitr(>-i'OTn|H)uiKl>,  :ti>7.                     ^^H 

^H          Hyriti'iiii',  390. 

-nitro«'>ki<r.onr.<.  249.                         ^^^| 

^H        Hrpurhmin  uf  Avckudko,  13. 16,  17. 

-piithalic  ii4:-id.  423, 445.                    ^^H 

^H         liypoxaaLhini:,  3Ji|  525. 

-prop>l  uU-obul,  51.  57-30.  177.             ^ 

^B 

-uniinir,  S2.                                      M 

-bcnzcnir.     tf«c  ntmttn.                ^^H 

^^L       Imini>cUoritlc«.  123 

-cikrliinol,  51.                                  ^^^| 

^^^^  •«tbi.-n»,  123. 

iodide,  Hit,  iSt.                            ^^H 

INDEX. 


543 


Iso-purone,  335. 
-purpuric  acid,  429. 
-<]uinorme,  508,  509,  514,  518. 

sulphate,  508 
-valeraldehyde-atnmonia,  246. 
Isomerism,  2,  42-48. 
of  the  alcohols,  51,  52. 
amines,  S2. 
ethers,  76. 
Optical  or  stereochemical.     See  atef' 
eoisomermn. 
Isomers,  43. 

Number  of  possible,  47,  48. 
Physical  properties  of,  48. 
laoprene,  155, 
Isotonic  solutions,  17. 


J. 


Japan  camphor.     See  camjAor. 
JuLiKa'  chlorocarboD.     See  kexackloro- 
bemene. 

K. 

KKEULi,  343. 
Kerosene,  40. 
Ketization,  302. 
Keto-aldehydes,  249. 

-compounds,  299-302. 

-hep  tarn  ethylene,  342, 

•  hexamethylene,  342. 

-hexoses,  255. 

-pentamethyiene.  341,  342. 

-poljTnethylene  derivatives,  342. 
Ketone  acid  sulphites,  129. 

alcohols,  254-289. 

decomposition,  292-294. 
Ketones,  58,  135-133,  139,  140,  151. 
153,  166,  174,  177,  323,  390-391. 

Mixed,  128. 

Unsaturated,  169,  170. 
Ketonic  acids,  243,  390-297. 
Kctoses,  255,  365,  267. 
Ketostcanc  acid,  165,  166 
Ketoximeo,  130-132,  391,  393. 
KiPPiNO,  240. 
Kjeldahi.,  8. 
Kijmun,  316. 
Knop,  323 
Knork,  S03. 
Kolbe:,  2.  198,  430. 
KoN-iGs,  505,  518, 
KOHNKR,  415. 

Principle  of,  443,  445,  446. 
Krafpt.  164, 
Kdstkr,  232. 


L. 
Laboratory  methods,  24-35. 
Lactams,  244. 
Lactate,  Zinc,  220. 
Lactic  acid,  316, 218,119-333, 239, 240. 

fermentation,  219. 
Lactide,  318,  220. 
Lactobionic  acid,  274. 
Lactone  formation,  Velocity  of,  225. 
Lactones,  2l2,  219,  333-335,  261,  263, 

267,275,338,421. 
Lactonitrile,  331,  243. 
Lactose,  219,  220,  254,  269,  373,  374, 

276,  283. 
Ladenburg,  444, 492. 
Lffivo-rotation,  61-65. 
Lffivulinate,  Silver,  269. 
Lcevulinic  acid,  269,  395, 
"Lakes,"  484. 
Lassaione,  4. 
Laurent,  2,  34, 
Laurua  campkora,  452. 

LAnWERENBURGH,  176. 

Law  of  AvooADRO,  13,  i6, 17, 
Behthelot,  30. 
Boyle,  16. 
dilution,  112. 
Gay-Lussac,  16, 
Lead,  Sugar  of,  108. 

White,  108. 
Le  B1.AKC  process,  289. 
Lecithin,  187. 
T.«ucine,  246,  522,  527,  52a 
Leuco-bases.  464. 

-malachite-green,  462. 
Leuconic  acid,  414. 

pentoxime,  414. 
LiEBiQ,  2,  5,  9,  279,  311,  323. 
LiKBREiCH,  253. 
Light  oil,  353,  488. 
Lignin,  262,  387,  288. 
Ligroln,  39. 
Limonene,  454,  457. 

tetrabromide,  454. 
I  jnalol,  456. 
Linen,  287 
Linkings,  F'ee,  98. 
Linoleic  acid,  167. 
Liquid  paraffin,  40. 
Liquids,  Separation  from  sohds.  31. 

Separation  of  immiscible,  30,  31. 
Lowering  of  freezing-point,  16-20 
Low  wines,  S5. 
LuMiERB,  430. 
LutidincH,  491. 
Lutidinic  acid,  495, 
Lyddite.  429. 
Lysine,  247. 


^^^^544                       ^^^                SNDEX.                   ^^^^^^^^^^1 

^^v 

Uercaptidc,  "LeaA,  7S.                        ^^H 

Mercury,  78.                                   ^^H 
Uercaplideit,  77.  78.                           ^^H 

^^L^_  Uiuteira,  £5. 

^^^KlUecoUs  137,  252.  46S,  ^6. 

Hercaptolc.  DiroethykKethjl-,  140.          1 

^^^H  llunMium  hAlidM,  Alkvl,  96, 1 1$,  130.  ■ 
^^^^■|li]iw:hil*-are(tD,  463, 4^7. 
^^^^■MftMc  miaA.  3O1-307,  236,  437. 

MtrtMriitli*  pervnnU,  S6.                        ^^H 
Mercun'-alkrU,  96.                            ^^fl 

-ph<^nvl,  %3.                                      ^^H 

^^^^K     nnhydride,  209. 

Mesitylane,  350.  354,  444.  44A,          ^^H 

MeaitylAoioada,  44S.                        ^^^M 

^^^■lUlie  uM,  201.  i>6,  240,  20a,  616. 

^^^VXalonie  wid,  167,  \»K  i03-ig4,  19S, 

M««(vl  oxidp.  166,  170.                       ^^V 

^V             IS8, 2U8,  2&r>.  :{:)o.  km. 

Mesotanaric  ackl.  226,  227,  230.  "m,    1 

^^B              OUT.     Sec  dieihijl  malanaU. 

JM-3J7-                                                  1 

^H                ByncbcdB,  103-196.  293. 

Mc90tartrat«.     Potassium     hvdn>cni,    ■ 

^^L        Uilonylurm.     Hli'  boHfUunc  ociJ. 

235.                                                      ■ 

^^^K  MAltosc,  rji.  2B1. 

McMxalatf,  Ethyl.  2S5.                             ■ 

^^^^■lbltobioni«  ncid,  273. 

Uc0oxalic  acid,  ifts.  328,  HM.                  M 

^^^■-Ni>]t<NmJconi>,  273. 

MMOXfilylun-a.     Hm  clivxan.              ^^fl 

^^^■lUlUMC,  54.  272,  >72.  275,  281,  2»4. 

SJHa-e^mpavn^,  347.                         ^^^| 

^^^^  MuMlclir  acid,  d-,  437. 

Mrtaldvhvdc,  13S.                             ^^H 

^m          r-.  239, 437. 

MetaUo-alkj'k    Soe  aJJtuU»,  mtUtai^^M 

^H                  KsM-iiue,  2dU,  437. 

Mf>ta«t}-rol<>,  40.^.                               ^^^| 

^B         btanniiol,  rf-,  183,  1S4,  259,  267. 

MrthiM-r>-Iic  arid,  1*3.                                 V 

^H 

Mpthane.  :;2. 36-38,39. 42,43, 154. 170.     ■ 

^H         MiuinohrptftM'.  2i^d. 
^^1              -bcptomc  a4?id,  283. 

Hi>!'i(ti-(i  drriviiitvps  of,  171-174.           ■ 

hoinoioe>irs,  HalofSFo  dm\-ativi»  of,     1 

^H             •nouotK,  269,  282. 

174-176                                                    ■ 

^H             -ocUmc,  269. 

Byiillituiii,  [tcHTHEt.ot'H,  36,                    1 

^^H              -BMcham  ft<i(!,  d-,  367,  271. 

S.^n.\TiBH  and  t^EXDeaiuta',  36.          M 

^^H         i'MiuiDonat«j  Str^-chrine,  267. 

-tri>rarboxvli'^  &«id,  2t>S.                           B 

^^K^  Miuuvoni'?  acid,  d-,  2l>7. 

MMjiodrt,  LiJioriitor\',  24-3S.               ^^B 

^^^K 

Mt-tttoxj't]iiitiultne  {S),  519.                ^^^| 

^^^P  MfliuicMe.  d-,  2fi9,  267.  3ti8,  271,  281, 

Methyl,  39                                              ^^M 

^^^^           2»2, 2H7. 

-Mecwiilid",  372.                                ^^H 

^H 

-tii'i'rli'  iicid.     i^  propionic  aaid.          H 

^H              K  168.  2S1. 

-(Wftoawiie  (yrtiiT,  297.                             H 

^^B          Mnnufmctuic  of  ethyl  alcohol,  54. 

iilioliol,  .11.  52,  53.  8ft.  105,  137, 192,    ■ 

^^K         Marckwald.  ^Sid 

322,  3r2,  373.  504.                                  ■ 

^^M         BIarg«ric  ftcid,  104,  104. 

-aniinf ,  S3,  85,  86,  172.  310, 314, 323     ■ 
-b<ni!*ne.     See  tWMfir.                      ^^M 

^^^^^  Moncanno,  109. 

^^^^B  Uargnrylmi!lh)'lkflnn<>,  164. 

hramidt^,  70.                                       J^^H 

^^^^K  MartiuB  yellow,  Al!,. 

■iMiiyluretoacclic  esM^r.  2M.           ^^^| 

-fi-biitvliio'lii-  Hcid.  266.  394           ^^^| 

^^^^^vlIcCoY's  boiliag-iKiint  apiMUVluft,  29, 

-r'nriiviiimitii?,  98.                               ^^^| 

^^^^ 

ctilondi^.  70,  144,  :I22.  SFi.              ^^| 

^^m        Mccunic  acid,  ^17. 

tv»[ild)',  9K,                                        ^^^1 

^^H        M^'oonin,  518. 

-11I13I cihiT.  73.                             ^^H 

^^H         Meconiiucai'id.    Svv  nwci?nm. 

•arptk  Aciil.     St«  vaUrie  acid.           ■ 

^H               Ml-itHllOD-.-.  2^. 

-varbiiioi,  .Vi.                                         H 

^H          Mdlilic  ndd,  22.  433. 

-luninr,  82.                                             1 

^^H          Mt'llmg-poiiit,  r)i^ termination  of,  32. 

•k^loDO,  138.  139,  249,  207.              ■ 

^^H          Mi:Hi>ELEJE{f ,  94. 

-inalonic  ftoid,  n<(,  194.                       M 

^H           .Mi:V»U'iUr-!KIN,  )s3,  121,  Zm. 

-iiuU  'if,  /?-.     .S|.<«  nknlote.                           H 

^H          Menthol,  239.  455,  458. 

iodide,  70,  .^-1,  372,  375,  504,  615.        ■ 

^H          Mt-rt'iki)l.iTi.  Ethyl-,  HO. 
^^^^       Mrth>l-,  78. 

-isc-pixj  ))'l.bctu«»e,  j^.    Sw  cj/m^iu.     1 

iidiiii.-,  51.  60.                                 ^^^ 

^^^^kMercaiilanB,  77,  78.  314,  333. 
^^^^FtleiTuptidi;.  lUamuib,  7S. 

-lo'ioni-s.  130.  152,  293.                 ^^H 

iimgttii-.iiiiiu  iodide  «ther  ODmpod^^^l 

^           CuppcT,  7& 

307.                                      ^^^1 

^^^^^^^^^^^^^INOEX,                                                   S45 

P 

Methvl-n&phth«I«Be,  a-,  473. 
.              $'.  47.V 

MonoMlkyl-chloro-bcstcnc,    349.    356, 

360,  300. 

1          -nonylketonfl,  130,  J93, 

-bciuopbraoiw,  302. 

•oraTiito,  418. 

-elher,  185. 

-phiruyl-hvdraiinp.  2rifi,  404,  503. 

-fluccinic  acid,  226, 

-pyrimiilonr.  503.  5(M. 

ealer,  20S. 

-plinsphiuc,  fiS. 

-fomiiii,  I8(m82. 

1 

-j>r(iiivl-<-nrljiQol,  51,  60. 

-liydroxy-oddi*,  Aramatic,  430-433. 

-kyiom-,  127. 

•iodo-ac«tic  »cid,  212. 

-pyHdiDcs.     Sec  pKoiint4. 

-benMoe,  360. 

•lliio|>hrn.     i:?««  (Atoto^m. 

•■nethvl-nllcaui,  332. 

1 

-viokt,  .|«6. 

•ATiiliTH'.  37 1 ,  37»>  -tOl. 

' 

Moiliyliilfd  otbrr,  73. 

-pho^phinitf  ftcid,  03. 

spirii,  57. 

-ureji,  Xt2. 

1 

Mi'tlivlniion  niclttod,  Ewn.  FiacTfen's. 

■ritmthiophcti,  502, 

334. 

■MKvhaddes.  254. 

Metlivlcne,  H3. 

•Midiomalonlc  c«t4>r,  193,  194,  195, 

1 

fhlorulr,  172.  4fi2. 

196.  208.  200. 

-(liiihrnvliiinnilnL*,  319. 

Monoooa,  354-37',  2^. 

iodide.  l7I, 

SUnaehviuimry  of,  3tl^2i'i. 

Met«r,   Victor,    14,    175,  450,   5», 

MordantinK,  416, 

«B. 

MonUutts,  108,  417,4»4. 

Hsiogp nation  rtiMhfHJ  <rf,  175, 

Morphine,  617,  SIS. 

Vapour  density  n[i[NUiiliis  of,  14. 

MOUKETRAT,  175. 

Milk-«iiB'"'.     See  J(i<fow. 

MuciCApiiJ.2ea,4W(. 

Mii.uix'  ^n-wnt,  523. 

Mucins,  524,  S'S- 

Mixed  rrv<itBi9,  241. 

Multi-rot  at  inn.  163,  2tH,  269, 

ntu-T)-.  IW. 

Murcxtdi".  323. 

krtoti",  128. 

Musrnhiic.  289,  514. 
Musk,  AriifictaJ,  415. 

Hixtuivs  of  Unuid^,  Scpuralion  of,  27, 

28. 

Mueturd-oils.    svv  (Atocyunic  acid  Uo- 

Uobile  oquilibrJutn,  Principle  of,  109, 

fjler*. 

no 

Myona,  524. 

JAoj6ii\s'»  Iheon."  of  Ihr  fommtifln  of 

)lyn[>yl  aloolio),  66. 

' 

IM-trulruni,  11. 

' 

Moliwrx,  24.^,  J77. 

N. 

ilolncular  clpctric  condurlivily,  3ft. 

foriiiuJO'.  12. 

Naphtha.  39. 

](7vrvriii|c  aS  iIk  frucKtnK-nuint,  Ifl. 
■wcighl.  DctennitiAticiD  of,  12-21. 

NaphthulcDt^.    22,  330.  351.  364,  365, 
419,  443.  470-478,  494,  fim,  512. 

olhv'lrogen.  13. 

-diciu-buxvlJc  acid.  Peri  -,  473. 

Moieculo  of  carbon.  21, 23. 

-«lihydrii|p,  472. 

Mononlkvl-pbairphinu,  92 

.«ii1phcni(!  arid,  a.,  474. 

-basic  tiydmsV-jirids,  21ft-223. 
uni'alurated  acids,  IA1-I67. 

;8..47-l 

t*irachiciride,  477. 

-br(>tii(»-a<-ciaJdf  liyde.  2(M). 

Nn|)litluu|iiitioDp,a-,  470> 

-Rcrlic  ncifi.  212. 

,?-,  47fi. 

-bcnacnc.  344.  349.  352.  jtio.  371, 

N.iphthcn^s,  3.15. 

372,  382,  3»l,  3!>»,  432,  461. 

Nuiilitliiiiiiic  Hciil,  475. 

-bciizophoiiuni-,  392. 

Napliihoii:  iwid.  0-,  173. 

^^^m 

-hiitylcni',  UH. 

^-.  •(73. 

^^^^H 

-erupic  acid.  216. 

Naphthol,  <t-.  379,  471.  474. 

^^^^^H 

-mirHntc  ai^id,  201. 

i?-.  -171. 

^^^^^^^1 

-Ihiopht-n.  .'JCK]. 

.tllxiiiphnnlr  vid,a-,  475. 

^^^^^H 

•«srbonyL  bond.  273. 

•monosul phonic  acid, «-.  475. 

^^^H 

•«bti)ro-wwtal,  2K{I. 

-tmul|)hotiic  acid, «-,  475. 

^^^^H 

-BCeticiM-ii].  192, 111, 113,219,245. 

-ycJIow,  47,'>. 

^^^H 

ester,  20s.  247, 2M. 

Noplilhjltinuiir.fl-.  474,  475,  478. 

J 

^^^^^^H 

546 


INDEX. 


Naphthylamine,  ^-,  474, 475, 478. 
-eulpnonic  acid    (1:4).      See    napK- 
Ihumicadd. 
Narcotine,  518. 
Naphthalene,  22. 
Nascent  hydrogen,  37. 
Nef,  98,  158,  316. 
Nernst,  337- 
Neurine,  159. 
NicotiajM  tabactim,  516. 
Nicotine,  494,  514,  516. 
Nicotinic  acid,  493,  494>  516. 
Nitramines,  321. 

Nitraniline,  m-,  413,  414,  427,  439,  447. 
o-,4iS. -127,  430. 
P-,  413,  416,  427.  439- 
Nitranilines,  438,  439,  449. 
Nitric  acid.  Test  for,  371. 
Nitriles,  97-100,  122,  131,  392,  398. 
Constitution  of,  97,  98, 
Hydrolvsis  of,  99,  loi. 
Nitntes,  Alkyl,  88. 

Nitro-benzene,  349,  362,  365,  370,  376, 
377,  379,  380,  381,  382,  397,  416, 
430,  448,  465,  505. 
-diazonium  chloride,  p-,  397. 
-benzoic  acid,  m~,  439,  448. 
0-,  439,  448. 
P-,  439,  448. 
-benzoyl  chloride,  o-,  509. 
cyanide,  o-.  509. 
-formic  acid,  o-,  509. 
-benzyl  chloride,  p-.  4fi8. 
-broniobenzene.  m-.  449. 
0-,  449. 
P-,  4 19. 
-butane.  90. 

-chloroanilinc,  (2.5).  447. 
-cin  nam  aldehyde,  o-.  500. 
-compounds,    88-91.    349.  364-368, 

414,  4'S- 

Action  of  nilroiis  acid  on.  90.  91. 

Electro- reduction  of,  378-380. 

Pnmarv.  90.91. 

Secondan-.  90.  91. 

Tertiary ."90.  91 
-dimcthvianiline,  p-,  373. 
■ethane,"  89.  91. 
■glycerine.  183. 
-guan'dine.  327. 
•  meaidine,  445. 
-methane,  89.  40.5. 
-naphthalene.  443,  444,  474. 
-paraffins,  88-91 
-phenol,  m-,  427,  429. 

o-,  415,  427,  447. 

P-.  4111.427  447,502. 
-phenyl-acctic  acid,  0-,  510. 


Nitro-phenyl-nitromethane,  m-,  367. 
-phthalic  acid,  443. 
-propane,  Secondary,  90. 
-salicylic  acids,  433. 

nitrile,  o-,  450. 
-fltyrole,  405. 
-toluene,  m-,  366,  371. 
0-,  366,  370,  439. 
jh,  366.  370. 
-xylene,  445. 
Nitrc^n  atom,  Aaymmetric,  374,  375. 
Detection  of,  3-5. 
Estimation  of,  7-9. 
Stereochemistry  of,  393,  393,  468. 
Nitrosamines,  84,  85,  372. 
Nitroso-benzene,  370,  379. 
-dimethyl aniline,  p-,  373,  426. 

hydrochloride,  373. 
-methylaniline,  372,  404. 
-phenol,  373,  426,  427. 
-pinene,  453. 
-piperidine,  490. 
Nitrous  acid.  Action  on  amines  of,  84, 
85. 

Test  for.  418. 
NoLTiNO,  445. 

Nomenclature  of  the  saturated  hydn^ 
carbons.  39. 
alcohols.  51,  52. 
amines,  82. 
Nonane,  42 

Nonosea,  a6i.  269,  280. 
n-Nonyl  alcohol,  52. 
Nonylene.  142. 
Nonjlic  acid,  104. 
Normal  carbon  chains.  46. 
primary  amyl  alcohol,  51. 

butyl  alcohol,  51. 
propyl  alcohol,  51 
secondary  butyl  alcohol,  51. 
Nomarcoline,  518. 
Nucleic  acids,  524.  525. 
Nucleins.  510,  525, 526. 
Nucleo-albumins,  524,  525,  526. 
SalU  of,  525. 
-proteida,  524,  525,  526. 
Number  of  carbon  compounds,  2. 
possible  isomers,  47,  48. 

O. 

Octane.  39,  42,493. 
Octoses.  261.  266.  369. 
n-Octyl-acetoacetic  eater,  293. 

alcohol,  52. 

-amine,  86. 

iodide,  293. 
Octylene,  142. 


^                              INDEX.                                                   547 

Cftl  of  l»ergamot,  AM. 

Oxiilati>,  Potiunuin,  190. 

biUcr  alin»iid«,  343,  380, 

ferric.  181. 

camiway.  IMS.  aW. 

ferrous,  191. 

ciniiaiuoii,  40.V 

,'>odiuii).  190.                                                        J 

dirm,  -IM,  4fi«. 

0.<uLluric  Kid,  328.                                             ■ 

dovts,  -tSS. 

OxAlvlur«D.     See  paraiani«  ocmL                         H 

cumin,  343. 

Oxinmc  neid,  102.                                                    ^ 

cuciJyphM.  3M. 

OxHmidf.  192. 

oerttniiiiu,  -155. 
IbaloeM.  4.V). 

r,»ximthfniiol,  IS2- 

Otidnllim  riii-tli'Kl  of  nniUysis,  4. 

Oximes,  130-131.  243,  30i-3M> 

uraneea,  454. 

St^rvohomeium    of    the    iLromaLic, 

pcppfrtiuiit,  4fiJJ> 

393. 

pine,  4JM. 

Oxindoir,  r>10. 

Tiw?«,  4  SO. 

Oxoiiium  taltx,  305-307. 

nif.  293. 

Oxyievn,  Dt^lcvlion  of,  S,  10. 
IMvrminiitionof,  10. 

»ninf  n,  ins. 

tho  Duich  (."hPinidif,  178, 

TPtravalenev  o(,  304,  305. 

thvme,  ;1S-1. 

Oxy.h»nionlot>ln,  SJli. 

tuVpPolini-,  3$7.  -IS-t,  45>-  453- 

•miMhvlt'nc,  137. 

n-inteT-itr"'H.  *'•^■ 

Oiokerile,  40. 

OiK  Kiht-rtiil.  432-4o1. 
OItfi»til.  j[ti.i.     t?e«!  tthiilenv. 

■ 

P. 

Oldiiiw.  I4>  -150.  *'^- 

Oli-ttt"--.  Li-aJ,  104. 

pABTs  Tjm  Tnoosrwrs,  176. 

Ulmt-  wkl,  IIW,  161,  163-165,  1(16.  182. 

Palmitic  u«id,  lO-i,  109,  110,  IM. 

scri'-s,  llil-IttS. 

PajKtrfT  iomntjeniM ,  517- 

Pl^iiwi  (ina\  -IS4. 

Piipcr,  2R7,  28S. 

Open  chains,  33S. 

PnrBbitnie  .teid.  318,  320, 

n|Hiiiii,  517.  .ilS. 

/*iirii-rotii|>iHiiids,  3)7. 

Optical  liiolivii)-,  33,  61. 

I'lirBcviiniiETii.  30S. 

iwMiii^rinin.     See  <hTiMMommi»»n. 

J'araffin.  Liquid.  40. 

Organii'  ohritiistn-,  (.laasificaiioii  of.  35, 

PiirnlTinH,  39,  S-W- 

Dctnilioii  td,  1. 

Pnrnffin-nnx,  3ft.  40. 

OrieulJtliun.    348.    407,  441  448,   473. 

Paraldehi  dv,  134,  133, 

ISO.   IBI.  -m.  501.  507. 

Piiru-kuciiiiiliiir.  -165, 

Oinilliiiw-,  J47,  327,  522 

-rosatiilinr,  4*i.',,  4C>B. 

Emil  Ft^oiEiiVnynthritis  of,  A'1'2. 

Ay*.     S^™--  paraTtminilint*, 

Ortho-fwi-'ttc!  AciA.  107. 

-rostuiilinec.  -Itit),  -1117. 

M-iiiTM.  ne.  177.  iJM- 

Pan-hinciit -iMwr,  2>J>{ 
P.MirEUii.  72.  23S.  24(J.  279. 

'furriuc  turiii,  172. 

wUT,  172. 

Pe*n  de  St.  Outtra,  117. 

OrfAn  .com  pfwini  I* ,  .147. 

I'i-lnrii(iiiir  iicid,  i:i!l.  lii.^,  160. 

Oaanoncs.  ajfi.  273. 

I'ettirttlmm  glaufvm,  240. -137. 

OMimiit-  jinvBHrr-,  13,  16,  17,  19. 

Pi:nU-(liliirii-lH-nwd  daluriili-,  408, 

Oeonw,  200,  267. 

-rlliani",  I7,^, 

UftT,  233. 

Oirrft  volution,  133,  2&S, 

-hydrit:  alcoiiols.  183,  1B4.  2Xi. 

-iiiclliv|.fj(.-tij!..iiiit»ili-.  .I.tO, 

0«Tflr»LD,  112. 

-p{irarrt«iiiiiiir>i-.     A—  melh'it-naid. 

OL'nBMANX.5IK. 

.nu>Uivliiii-,  IhO.  341.  342,  41*. 

Oxalic  Bcid.    163,   180-182.  1S9,  190- 

di-rivaiivcp.  310-342. 

191,  248,  2T7,  290.  296,  302,  3(M, 

•dianiinp.  1B6, 247.  489. 

308,  328. 

li>i1r()rhloridc,4S9. 

Oxalacci  ir  acid,  296. 

-trineoiitane.  38,  4a. 

cslrr,  29fi. 

'VaU-tii  iiiiniKi-i)  iitom,  S6. 

OuJalc,  AdiDonituii,  30& 

nPoiituiu-.  43.  m.  150.  174,  4S8. 

Cbloium,  100,  191. 

IVmon.:'.  38,  47,  02.  H4. 

Elbyl,  39S,  803. 

Pontttnie  »c'dd,  353,  262. 

jifoex.                             a^^^^^H 

Penloaana.  282. 

Phenyl  •iao•c>-nnnt4^.  3fi7,  J76.                 ^^^^| 

PciiUMe».  133,  363-164,  2H3,  234,  497. 

•tbiociraaate,  376.                           ^^^H 

Pcntfltfuria,  2(i2. 

iTiagriesium  bromide,  38&                  ^^^H 

Pcntvt  iodides,  117. 

•intrreury  ftceMte,  3^                        ^^^H 

Pepper.  403. 

hydTAxide,  3S2.                                         ^M 

Peptones,  524,  515,  S26. 

miiaUid-oii.     !?ce  jAm\fi  ixalhioeya- ^^^^ 

Firmiiila^c-eomposilion,  10-12. 
IVrpolntion,  515. 

note.                                            ^^^1 
•uitromelliiLnn,  366.  367.  37S.             ^^^| 

Pm-compoundu,  472, 

-phosphenyl  rhloride,  ^1.                 ^^^H 

Pfritxli*'  inslem,  94. 

-phoaphinrc  an*l,  3KI,  382.                   ^^^H 

Pebkis,  \V.  H..  tiEN.,  301,  4W,  437. 

'phwipliiiu-,  3B1,  382.                            ^^^1 

-phoffphinmi?  arid,  ."^SZ.                      ^^^H 

Petroleum,  39, 40,  US. 

-prgpivlic  im:\A,  405,                              ^^^^| 

^K           -41  her.  39. 

'salievlat'',  Sodium,  431.                    ^^^H 

^P            Oriffinof,  40,  41,  155. 

ftiilphlde,  39s.                                    ^^^H 

Refined,  40, 

-iireihjun-.  375,                                         ^^H 

"Ph«nioh's  aerpenta,"  314. 

Phenvlene-dianiine,  m-,  414,  415,  4I&         H 

Phcnwi'liii,  4.10. 

U:,,  447.                                             >^^ 

PhriiiiiiTlir.tciiiitKinF.  485.  ^t6. 

I^^H 

PbcTiftiiihmi.-.  470.  4711.  485.  486,  318. 

;>-.4>S.41$.                                 ^^H 

Plu-iieiuk-,  364.  307.  430. 

tliiidptiDiuc  acUl,  m-,  40ft.                    ^^H 
PhluroKlucinol,  3G0.  288.  410,  411.         ^^H 

Phtnol.  Xil,  352.  :(««.  j6i,  36J.  363, 

3fi4,  3!»7.  3!!!),  402.  417,  421,  424, 

-trii'iirlicixv1i<- Mt^r,  411.                       ^^^^| 

426,  428.  432,  447.  522. 

-trioximi>,                                                ^^^^| 

1                   -sulphonic  oeid,  m-,  424. 

Phorone,  109.  170.                                    ^^H 

I                       ».,  4m.  414- 

Phm^'Di*.     .■^i>  atrltcmul  ehiitiSt,          ^^^H 

^_                 n-  412,414. 
^H            •phlhala^m.  421. 

Phu«|)l)inn I  rhlnride,  3S).                           ^^^H 

Phosplirnylou's  ncid,  3S1.                         ^^^H 

^^        Pbenob,  360-361,  30S.  3S9. 
r                 Pilodrir.  400. 

Pbaiuhtuu  o\idf-H,  .\ll(vl-,  92,  93.         ^^^| 

oxidi!,  Tricthvl-.  93.'                          ^^H 

1                  Polrhvdrif,  409-411. 

oxide,  Trimctbvl-,  93.                        ^^^H 

1                   Tfwt  for.  302. 

FboepliirLCM,  92.                                         ^^^| 

1                  Trihydric,  110,411. 

Pbortphinic  lu'id.  Dimethyl*,  93.           ^^^| 
Monomi'i  Kvl-,  93.                              ^^^H 

^^H         Phenoxidp,  Pnnutnum,  361,  431. 

^H            Sndiiini.  j6i,  415,  430,  Am. 

ikcids.  Alkyl-.(I3.                                   ^^H 

^H       PhenoxtdM,  301. 

PhospliinLibetUL-iie,  .181,  382.                   ^^^| 

^^H        Pheaoxy-anivlatnine.  *-,  490. 

PlKJAliliD-lH-iif-i-iie.  381.                              ^^^1 

^^H           -volerii'  nc'nl,  d-,  4.'0. 

-Ummtir  :icid.  323.                                ^^^| 

^^B           -vnlcronitrilr,  i-,  -ISO. 

Phosphoniiiiii  bofics,  QuKtentftty,  92.          ^| 

^^^       rhi?nv].acctBtr.  Etbvl.  300. 

PlioH]>ltoriin,  Dvlfiction  of,  3-5.                ^^^B 

^H           -itcelic  su-id,  387,  ^. 

Ik-tcnnitiutinn  of.  9.                              ^^^H 

^^B           -aeelylene,  40o. 

Piillkalaininii^  nrld,  438.                               ^^^^| 

^^H           -amine.     Se^- aniline. 

I'hthAlrina.  4>i,  407.                              _^^^^l 

^^H           -nrB-nii-  o.xidc,  381 . 

Phthjilie  acid,  419,  430,  444,  403;  47B^^^H 

^^B           -amnicnc-id,  iSi,  382. 

.5011,  .i  12.                                            ^^H 

^^H            carlmnatc.  Sodium,  431. 

Ti^ffl  fni-,431.                                      ^^H 

^B          cihi^r.  3414. 

Bcid«,                                                       ^^^1 

^H          -hvdnuinr,  132,  2A:>.  2;ifi.  264,  273, 

anhydride,  430,  421, 481, 4S4.             ^^H 

^H               38G,  360,  4«i-4«4.  !>03,  501. 
^^m             fcydtxK'hIundc,  403. 

T<-Jitfrjr,421.                                     ^^H 

i.io-imide,  423.                                       ^^^^| 

^^^^f            -aulptiimiit^,  Sixliuiii,  403. 

I'ht  lialidi-.  420,                                               ^^^H 

^^V*         -hWmroniv,  131,  284. 

Phthalimidf',  431,  430,  512.                     ^^^H 

^^H          -hydroKyltk'Tiine.  379,  380. 

PoiiuMLiim,  411,  422.                             ^^^H 

^^H           -^'•lijdruxyprojiiuiiie  acid,  a-.      Son 
^^^^                    tropic  nna. 

Phlli:il(>nh<'ii<>ni\  420.                                   ^^^| 
I'hitialy]  cliloridt-, 4>o,  423.                              V 

^^H         -iodide    chlorido.    See    iodabvrttent 
^^^M                  dieitloritie. 

Phy.ticul  [irnin  n  \m  of  Iba  alcohols,  62.  ^^^B 
Moment,  48.                                ^^^H 

^^f          -iwcroUMilc  «id,  471. 

PicoUnc,  a-,  402,  493.                                ^^H 

^^m                                      INDEX.                                  549         m 

Picolinp,  ^.491,519. 

Pnomry  aminM.  Test  Tor,  99.                   ^^^| 

I^€oliiiM.49l. 

imiiust.  93.                                            ^^^H 

Piclionlc  arid.  4»3,  494. 

caitmn  ai«m.t.  46.                                  ^^^H 

Picrami*!*,  42S. 

compounds,  S2.                                     ^^^H 

Picmrn.  Ammonmn),  428, 439, 

nitro-coui  pounds,  90.  01.                        ^^^H 

Mcthvl.  428. 

Piiacipltt  of  KoftNBR,  443,  445,  446.         ^^^| 

PotMaium,  428. 

mnSilA  p<]uililmuin,  109,  IIQ.                      ^H 

Silver,  42*. 

Ptodueer-ipis,  &3.                                                   ^H 

Picric  arid,  172,  414,  417,  418,  447,  448, 

Proof-apjnl,  ^,  .'>7.                                               ^M 

462.523. 

Propiuir.  38,  39.  42,  44,  175.                               ■ 

Proparu'l  alcohol.  158,  160.                                ^M 

^d«hvde,  IISSI.                                                   ■ 

•naphthaleoe,  429, 
Pifrvl  fMoriilc  42S. 

Pimclatf;,  C»lciuin.  3*2. 

-ATfUll,  169.                                                   ^^H 

Pimclic  acid.  189. 

haLidna,  l&S.                                                ^^H 

PinjuruUii,  ITS. 

PropiolicKi-'id.  i4io,  J)H,                            ^^^H 

^^K  PiiuKooc,  177,  178,  329. 

scriw,  165.                                                      ^M 

^V  Piaenr,  453,  454,  456. 
^    '■Pmk«Ut,"4I7. 

PMpionaldchvd',  58.  ta?,  146.                         ■ 

Propionic  acid.  58.  07,  104.  139,  153,            ■ 

1          Finylunine,  453. 

163,  212,  21s,  222,  201,  297.                          ■ 

^^_        ttyrlro^hlnrirli*.  453. 

Propiontt.rit(%  98.                                            ^^^^| 

^H  Pfperi^  acid.  493. 

Propyl.                                                             ^^H 

^  Fiperiduie.  1S(J.  480.490. 493.  £17. 
hydrochloride,  469. 

-aL'elylene.  153.                                           ^^^| 

alcohol,  Nomud,  51,  52,  57-59,  157,              ^ 

Piporini;,  493. 

160.                                                         M 

Pitch.  a&2. 

Iw-.  51,  57-9Q.  in.                               ^^H 

PUl>iiol>-pef,  101. 

•Bmine,  82,  H^.  8.S.  86,  las.                    ^^H 
braniidt^j  Nonnal.  70.                               ^^^^| 
-CArhinol,  NormfU,  52.                           ^^^H 

PoUrirnetitr,  34,  278. 

PnUriMiion.  Kointion  of  the  pUinc  of, 

33-35,61.62. 

i^hloridi?.  Normal,  70.                                ^^^H 

Poliw.  CiirbiHi,  119. 

iixlidv,  NiirnuJ,  70,  Hti.                           ^^^H 

l'olvi.iwir-i«ciii«.  188-210,  419-123. 

-pi pi- rid i III.-,  a-,  492.                                    ^^^H 
6-,  403.                                                     ^^M 

-fivdnc  :^cofaols,  1 7&-I84. 

■phfiiols.  400-411. 
•intn'iyli-ni;   derivath-ea,    ISO,  34a- 

r-.  493.                                        ^H 

-p.'triirlimitrol,  91.                                                    ^H 

34>. 

Propvlcnc,  143,  146,176,  iSo,181,340,            M 

•ows,  354.  »55.  2'^,  383-389, 

^1.                                                     ^^M 

-sacchtiridM.     Seo  poiyorft. 

-fElvcol,  216  220.                                        ^^M 
Propvltdcne  chlorid^t,  146,  ISA,  180.           ^^^| 

-Itrpeni'Jt,  452. 

Polvmi'riiEntinn.  I3J. 

Proli>ids.  244,  247,  283,  327,  520.  524,            V 

PopE.Si,  240.374. 

535-                                         s 

PoBiiion,    .Ab-iolutu   determination  of. 

ProlentH.  530,  521;  525.                                        S 
Protooii'^rUuic  acid.  434.                                 ^M 

1                  441.-!  12-4  Hi. 
^^L        Rplnlivr  drtrrniitiiilion  of,  441,  442. 

Prussioa  blue  test.  A.                                            ^M 

^H  Foiaeh,  Alcoholic.  141. 

"  PnuMattt  of  potaah,   Yellow."    See           H 

^H       buUio,  0. 

ferroajanide,  polawum.                        ^^^H 

^^K    PoMMio-pyrralc,  llHl, 

PniMiic  ncid.     fwr  kifdr^nanic  acidr           ^^^^M 

^^V   Potawiiim-nlkyls  or  ttllciclRo,  95. 

Pw-tidrKHndi,  90,  367,  36S.                           ^^^| 

f             earbonyl,  411. 

'bnaee,  464.                                                  ^^^^| 

1                rvHiiide,  172.  3US,  310,  311,  383. 

-niiruU,  91.                                             ^^^| 

1             etlioxide.  SIS. 

•rupi-niic  mixed  crystala,  241.                ^^^H 

L.             ethyUulphmc,  73. 
^^L      phenoxlde,  361 . 

-uric  arid,  .131.                                           ^^^H 

Plairiiuru-a,  186.                                             ^^^H 

^^B      -aoBp,  lIOi 

Purine,  331,  333.                                       ^^^H 

^"^   Pnteim,  Osmotic,  13,  16.  17,  19. 

rodiictioii  curve.  Abnormal,  33Q.           ^^^| 

r             Vapwiir,  Ift. 

Noniiul,  ;)36.                                       ^^H 

1            Primnry  uloohnlit,  51,  .^S,  59,  102. 

derivatives,    KIcctro  -  reduction    qT,      ^^^| 

1                nminr*.  83-85,  *);  9ff.  ITO,  369-371. 

334-337.                                                  ^^M 

^^             UAHHiEL'ti  ByiithesLi  of,  -121,  422, 

Purity,  T«*ts  ol,  33.                                 ^^^1 

55°                        ^            lNt)EX.                      ^^^^^^^^^^^H 

Puronp.  33fi. 

Qiiinotannic  ariil,  ALS.                          ^^^H 

Purpunc  acid,  330. 

(juiao^ir  acid,  518.                             ^^^H 

Piitreiicmc.     isco    MramHhyltrMiiam- 

l^uinm-in,  518,                                        I^^^H 

('W. 

QuiDOXAlineB,  41£.                                 ^^^H 

Pvkrn.tiif1<-t,  33. 

^^^^1 

Pvr*»nl-,  3311,  501-504. 

R.             m 

Pyrnzoliiii-,  .W.1. 

PVnuinlinif,  .Vfl, 

Rimnalv,  (Inchaniiio,  239. 

P'^  n-iw,  2<J,  ♦87. 

f'nditim  iimtnoiiiutn,  238,  240,  211. 

I'vridin.-.  tti7.  2.iH,  2«7.  2(K.  290.  339, 

Raffinie,  ZH. 

aSl.  488;49S.  ■■'Wl.  .iH.  5t8. 

ai-iil.  22'-.,  227.  230.  23!.  JJJ.  ^34. 

-(Iii-&rt)o\vU(-iickl.  KM,  IU3. 

235,  2aS,  Kill.  2Vi|,  2S2,  2'.HI.  .1,^. 

mtlhyl  iodid. .  4*ifl,  41W. 

8iil»"lflm-<>,  Sfji,'initi"ii  01,  23.S-341, 

•nionocurboxvlic  «rid», 491 ,  493, 4^14. 

itaffincw.  2>t3. 

«ilt»,-lSK, -IH). 

I'ui.siti;;  of  boiltnit-pnint,  Iti,  17,  ao,  ». 

•«illpliiiiiii>  iund",  4ill. 

Ki'jirlHiii:^.  Kiimikrubr,  S3,  lao,  ^I, 

Pyro-*iHPcliin    or    p>-rocat«chol.    See 

PvftiKt'iietit-.  Vm. 

ttawfhot. 

i;.-\i-i«iblf,  117,  133,  134.  S3J,  3ZS. 

-BHllic  will,     Sw:  pyrugaHal. 

S(i-(initHr\'.  (J9. 

Kallol.  410.  4M. 

I'liiiiiolccidiir.  iia.  263,  321,  403, 

-jp-iKTlif  niwiioim,  128. 

licrincil  pttnilfiiiu,  40, 

-tadlitioix'Kl,  -123. 

Rclmt-litni,  ItiUui  of,  35. 

wibvdhili-,  123. 

Itrii-iiKTi.  ax).                                         ^^H 

-tnucic  mid,  487,408, 

Hfifi  Imrk,  518.                                         ^^^^1 

-raectrml*^.  PoluiMivini.  2111. 

Rvtiiii,  423,                                               ^^H 

•tavi-Tiiic  iit'iil,  21ii,  Z31 ,  190, 191, 21W. 

Ht^ifM.  69.                                               ^^H 

-tartaric  urid.  331. 

HMtinhi,     i'^vreanrtirv^.                      ^^^H 

Pyrone  derival  i\cs,  ;il)2-!lll7. 

-rclldw.      N^r    itiliydroj}fat»Aenitii^      ^m 

'•<Jii-arl>o\t'lie    add.     (xr    fhriuhnic 

s'tt  iihanir  arid .                                          H 
Rivion-iiiol,  409,  41K,  424,429,  411.              ■ 

arid. 

Pvrmk.  498,  490.  &03,  A18. 

-plithitlcin.     Sec  liuorumiin.                      H 
Tf«  for.  421.                                                 ■ 

-n"i,  Am. 

PytToli-liiie.     Soc  Mraftydroffjrrcle. 

Itcveniiblo  itoctiou,  117,  133,   134,      m 

I'yiTollne.     See  ttikydropj/rroU. 

32(),  335.                                                   ■ 

"KhoJinal,"  130.                                             ■ 

<i. 

Ithudiiiol.  451;.                                        ^^^ 

ttiritTKH,  M.  M.,  2.                                ^^H 

QualirAlivi!  atiiilyoiM.  3-A. 

ItomciitxjM.  LtAKatnn,  241.               ^^^H 

tjudnritulivr  niitilyNK.  A- 13. 

ItoduiiUioc,  465.  4l3li,  407.                      ^^H 

(juatcniArv  onuuouiuiu  bucs,  83,  83, 

{\ypn.     Sire  rmamtinta.                       ^^^H 

374, 373. 
ononium  hum^  93. 

Kvdnx-ld<>ri(iir.     Sw  fnagenta.         ^^^H 

liooaiiiliiii'M.  463-466,  467.                    ^^^1 

r«rl>on  ntoni".  4fi. 

Ii'i#<ili<'  urM,  V'ftl,  467.                                 ^^H 

plioi]>hoi)iuiii  >>aw^,  413. 

Ruialtoit  of  pttute  of  poUriutlian.  J3—     1 

KliliiMiiiini  liusex,  VJ. 

3S.  »].^2.                                                 M 

Quiiia-rr^.  518. 

llnintriiT  piiwpr,  Spwrifie,  34,  35.                ^| 

Quiiiie  arid,  SIK. 

ItiilRTvihric  acij,  4S3,                            ^^^H 

tjuiiiinc,  4:!.'i,  518,  S19- 

Autu  [rrui«uJ«n«,  293,                             ^^^^| 

tjnim.l.  40B,n2,4l3.4<H. 

^^^^H 

yuinolin.-.  207.  aiU,  3rtl,  4S8,  489.  4(H, 

^^H 

S«S-5o8.  514,r.ltt,  519. 

-c3rKu,\ylic  arida,  50S, 

Sabatieii,  .^6,  144,  15.5.                        ^^^ 

d*-rivativi'rt.  N  onu^ticlftture  of,  SOS. 

aiid  SENaiiiiENa,  Muthane  (nrnth««b      | 

dii'tiriiiiiuii',  505 

(>r.  36.                                                        M 

QiiiDrtHiiic  ai-id,  494.  411.1.  SOS. 

SacchBrRK-.  Cakinm  tri-.  176,  277.            H 

tiiiiiiutie.     S-p  brnioyuirMme. 

Puljuwjum  hvilruitcti.  205.                  ^^^B 

di-iniidf,  4)3. 

f^i-i-haniu-ji.  398.  270.                         ^^^| 

(^uiiioDtK,  4I2-I1-I. 

f^jjlitcthuric  4ci(l,  3S5,  271.                 ^^^| 

. 

J 

INDEX. 


SS" 


Saccharificatioti,  54. 
Saccharin,  425. 
Saccharose.    Sec  nwroia. 
Salicin,  430. 
Salicaldebyde,  437,  438. 
Salicylate,  Calcium,  431. 

Methvl,  430. 

Phenyl,  431. 

Sodium,  431. 
Salicylic  acid,  430,  43i,  433,  440. 

anhydride,  431,  433. 
Saligenin,  430. 
"Salol,"  431. 
Saltinn-out,  110.  417,  521. 
Salt  of  sorrel,  191. 
San D.M EVER,  397. 
Sand-.siignr,  274. 

Saponification  of  esters,  72,  119-iat, 
311. 

fats,  109,  121.  ir<3. 
nilrilca.     See  ht/ilrolnsia. 
Sarcolnctic  acid,  221. 
Saturated  dibasic  aculs,  188-201. 

hj-droearbonB,  36-48,  95. 
Nomenclature  of,  39. 
Saverkratit,  220. 
SCHIFP,  .300. 
Schizam'iceles,  279. 
Schizoxacckarotniices  octosprrrux,  281. 
ScMOTT^E.N.     See  Bausiaxn  and  Schot- 

TEN, 

Schweitzer's  reagent,  287. 
Sebacic  acid,  189, 

Secondar)'  alcohols,   53,  58,  59,    126, 
130. 
amines,  82,  84,  85,  371.  37a. 
arsines,  93. 

butylcarbinol,  5!,  60-62. 
carbon  atoms,  40. 
compounds,  53. 
nitro-coinpounds,  90,  91. 

-propane,  90. 
reaction.'^,  G9. 
Selenium  compounds,  80. 
Beuii-carba/ide,  323, 
-carbazones,  323. 
-tcrpeneS,  452. 
Semidi  lie-transformation,  378. 
Senderens,  36,  155. 
Senieh.  311,  316. 
Separating-funnet,  30. 
Separation  of  amines,  83,  85, 
immiscible  liquids,  30,  31. 
mixed  liquids,  27,  28. 
solids  and  hquids,  31. 
from  one  another,  32. 
Sericin,  528. 
Sericom,  528. 


Series,  Homolc^us,  41. 
Serturner,  517. 
Side-chain,  348, 
Silico-alkyls,  94,  05. 

-heptane,  95. 
Silicon  chains,  94. 

Chemistrj'  of,  94. 

disulphide,  319 

tetraethvl,  94, 
Silk,  Artificial,  288,  289. 

^lue.    See  aermn, 

SiLVA,   180. 

Silver  benzaniide,  386. 

-titration.    Voisard's  metbod,  313. 
Skatole,  510,  522. 
Skhaup's  synthesis,  505,  507,  508, 
Smokeless  powder,  288. 
Soap,  no,  182. 

Cleansing  action  of,  110,  111. 

Green.  110. 

Hani.  no. 

Potassium-,  110 

Sodium-,  110. 

Soft.  110. 
Sodio-acetanilide,  372. 

-acetoacet.ic  ester,  292-194,  297-299. 

-7(-ainylacetylene.  250. 

-dinitroethane,  308. 

-ethane -tetracarboxylic  ester,  471. 
-tricarboxyhc  ester,  209. 

-malonic  esters,  193,  194,  298,  340, 
410.489. 

-nitroparatfins,  89,  90. 

-plienylisouitromethanc,  3(i6. 
Sodium  alcoholates.     See  sodiwn  alls' 
oxides. 

nlkoxidcs,  49, 

-alkvls  or  alkidcs,  95,  101. 

ethoxide  or  ethylatc,  66,  172,  194, 
2.50.  292,  296,  300,  355. 

mcthoxide  or  ntethylate,  66,  73,  358, 
415. 

-methyl  or  methide,  101. 

nitroprusside,  5. 

phenoxide,  361,  415,  430,  489. 

propiolate,  165. 

-soap,  110. 
Soft  soap,  110. 
Solids,  Separation  from  hqtiids  of.  31. 

one  another,  32. 
Solvents,  32. 
Sorbic  acid,  167. 
d-Sorbitol,  265. 
Sorbose-bacteria,  260. 
"Sozoiodol,"424. 
"Sozolic  acid,"  424. 
Spacial   representation  of  the  bonds 
between  2-5  O-atoma,  200. 


55*^                       ^         WOEX.                            ^^^^^^^^^^M 

iipM-irtc  Knvitv,  13,  33. 

8itr>r-eiiiii<.  274,  276.                            ^^^| 

of  11011101;  S6. 

of  Imd,  XOS.                                        ^^H 

Speat  lee*.  JU. 

Siom.     iS«e  oldtAidt  and  itetone  o^o^        ^| 

wash,  fiS. 

Ao/ji.                                                        ^^^B 

8piril«.  &S. 

fHilphanJlic-  acid.  113.  434. 435-               ^^^| 

of  wrne,  rJi. 

KiJphinic  &r4(l>s,  8U,  304.                            ^^H 

Rponiciri.  »27. 

Sulpho-beiiBok  M.-id,  ih-,  425.                   ^^^H 

Sinrch,  &1, 2^1, 2M,  2A9, 373,  3S4-186. 

tf.  42&.                                              ^^H 

MdniifiK'lar.io*,  as6. 

«ilph«niidc,  IV,  425.                         ^^^B 

Poimo-.  2S&. 

-<!yani«add.  Hw  Ihioe^tme  oHd,              B 

IU«-,  2H5. 

Siilphnmil.  14n.                                       ^^M 

Rye-.  284. 

i4iilpluitiiimi(l<v.  357,  3J^.                          ^^^H 

SlMm  dlMilUtion,  28.  j^,  30. 

Sulpbonf-A.  7Q.  SO.  140.  304.                     ^^H 

BtwumtK,  Hiintim,  1<H. 

HulphDTiit-  wiilii.  Alkv!-.  79,  SO.                       H 

Stearic  HcJd.  102.  101.  ioq,  iio.  161. 

Aitiiiintic,  34S,  3U,  iS7.  J58»  36t.          fl 

"BtMriiie"caiHn(ta,  110. 

folv^  408.                                           ^^M 

8l«itT<)lic  ftrid,  165,  LM. 

rhloriJct,  .Alkyl-,  SO.                             ^^H 

Stcuryl  ak-ohol.  102. 

AronmUi,  357.                                     ^^^B 

&trrr<>-cliviiiit-«l  iwinerisin.   Sc««rmeA- 

ijulplic>\i<L''T<.  79,                                                ^1 

iiuMim'iirm. 

Sulphur,  I>vi«y>tiAn  of,  3-5.                      ^^^M 
Deti>niiiniitK>ii  of,  !>.                           ^^^H 

-chfiiiii'tr*'  iif  nilnitCi^if  •'W2,  JUi. 

^soDiori«m,    6o-6A;    3O3-20A,    2tfi, 
^K                  2in,    22<l,  22r>  2:11,    264,    208, 
^V                  2IK)-272,  2SI   2.'<i3. 

Snportvnskin,  336.  337.                             ^^^| 

Syntonin,  511,  SZi,  524,  £20.                  ^^H 

^^^H 

af  the  arnimilir  ():fim<'-«,  393. 

^^1 

diiturki-o  ID  pounds.  3UU,  400, 

S(lb!nf4(.  ''Vrtinn-,  tH. 

TAnti..  334-.')3d.                                   ^^1 

tiiitioLiiurn  bttf-^,  Qiiatcnur)' ^'l- 

Tuinic  acid*.    Sec  tannini.                    ^^^M 

t<U}t>Tm-.  46S.  485,  4ti8. 

TAtinin,  434, 435,  .SI  &,  $23,  527.               ^^M 

KtoniK,IU.%.lOft. 

Tntitiing.  43.^,  436.                                       ^^H 

Straw -(WiixT,  288. 

TdinuiiH,  i'Jn.                                                    ^^^H 

Strcntjth  u(  undo,  113. 

lur,  Jsi.  35»,  47Q,  488,  4»S,  499,  aOH,        ■ 

litnietiiral  foriaiilii*.  45-  OO. 

500.                                                               ■ 

Strj-rhiiiw.  2:iD.  433,  $^9- 

Timnr  eiiiK.ir.  231.                                            H 

Antitlulv  for.  Ain, 

TnrliirJF   atIiI,   <i>.  22&-Z3'>,    231-233.         ■ 

Stnjiftwa  fiaj'  I'crnKii,  AlO. 

234.  2:u.  237.  340.  2^2,  2M.                  ■ 

8tv|>hiik  ari<l,  429. 

r-.  22(^228.  290,   >J3.  224,   237.         ■ 

iitvrwir,  405. 

210,  Stti.                                   ^^1 

8twM>-l!il,lg7. 

Mcuo-.     lfo<-  mm>btr(nrie  ocui,          ^^^H 

JNMborato,  Cttlcium,  342, 

IUm-dmc.    S««  racmiKt  aa<l,           ^^^H 

KhImHi.'  Mid,  IMD. 

Tnriah«ncidtt,  22l>-24l.                           ^^H 

iiiilM'foiii'.     Sm-  kflithrpliimrlfifiletif. 

Tartr»u>,  Qilriiim,  231.                         ^^^H 

^^^      Kulwliliii'iilx.  liilliit'nco  on  eiicti  other. 

Cinflionini?,  2S0.                                      ^^^H 

^^1              4-IH-l.'>l. 

I'otiuttiiiiti.  2^11.                                              ^M 

^^•^     SiiliHiiiiiinl  addK,  211-247. 

TarCmir,  PiXuMium,  anlunonyl,  231.           H 

r              Sulisiitiiiion,  3S. 

hv<lTi<i:(-i).  2ill.                                       ^1 

1              tiucuiiat--,  bilivl,  200, 

Co[i|>i-c  Midjiini,  233.                               ^^^| 

1                  l*tit uoea HI u  ethyl,  IDS. 

^k>d)iim  nntmoiiium,  23M.                      ^^^H 

L             9tKCinic  luMd,  54,   lK<i,   1^-196,  IIIR, 

'rnrtr»iii«  !<'-i(l,  1711,  ItfO,  »3.                     ^^^H 

^K               201.  207,  213,  234,  221),  5WI. 

TnuioiiiiTiaiu,  397'JO),  233,  336,  333«        ^| 

^^H           (inhvdnd^,  I'JK. 

■ 

^^H       SitcriiiMinulp,  4!t!t. 

Tnulnni^rs.  Mplbods  of  d«t«c1.iiig  the         H 

^^H      Su(-riiiiriiiJo.  I'M. 

lTuri>ifi}ritiiiti<iti  of,  301.  302.                    H 

^H      Sui'roAi'.  2IU.  242,  254,  2G4.  2US.  2n. 

S<-jLir3liiiii  (if.  300.                                         H 

^M               274->8y 

Triliinviin  com  pounds,  fiO.                                ^M 

^V          Vrlocitv  of  iovcnuou  of,  278,  279 

TlH?'ioii    lUi-CKV,    vox    bABTXR'A,    ISO,           H 

r        Bucnr.  tOO. 

■               4mit,24fi.  374.  27^,378. 

>9(l.341.342,                                              ■ 
Tcrepbtlialic  acid.  343, 413, 4S2.              ^^H 

^^^^^^^^^^^^                                        ^^^^             553             1 

^^Tetminal  eartwm  ktanu.  46, 

Tetrn-vitlener  itf  eubon,  23. 

Torpchfs.  !,«,  35(,  451-458. 

Trtri>lic  u-idl  166. 

Ti^rpin,  -LW,  45.5, 

TetroMt,  262. 

hydrale,  4.'H,  465, 

TMnn.    S*«  m/^cim. 

Tprpincol.  4  ■'55. 

ThAohrominr,  33).  $}>,  XR,  614 

Terpinolinc,  457. 

Thieni'tmcthvlkciODc.  a-.  fiOl. 

TcrtUn'  tUruhole.  51, 60,  lift,  117, 130, 

Thio-acidfl.  )'21. 

Hi.  358.  361. 

•iddehydc»,  140. 

KninM,  S2,  84,  85,  09,  37>-J74* 

-c^-Mintc,    AmmoDium,    33s,    32C, 

imincx,  93. 

327. 

biBmuthinoB,  04. 

Tiarium,  ^13. 

butylcarbLnol,  61,  60. 

t'vrri<!,  313. 

rnrbcni  titnnu,  40 

L«ul.490. 

Cflmpoundi.  52. 

Mercuiic,  314. 

aitro-compounds,  &0,  9t> 
Teal,  Cvanidp.  5. 

PotiMuiiin.  313. 

Silwr.  313. 

(or  aF>«»liitc  nlcoho),  56. 

-ej-anic  acid,  313.  314. 

double  tinkint;,  142 

iso-est«TB,  314,  319.  335. 

elhvl  ftloohol,  57.  I7J, 

normal  ostcra,  314.                                   ^^^H 

hydroxvl,  IM,  115. 

-«tbor8,  77,  79.  3&4.                                  ^^H 

nit  rij-  !ii'ii!,  371. 

-kPt«D«s,  140.                                           ^^^1 

nitrouM  ariil.  418. 

•methylene,  315.                                           ^^^H 

phpiiols,  3fl2. 

-plK'iuil,  34{l,  3«3.                                         ^^H 

phtttatie  acid  and  anhydride,  421. 

.ph<-nol<>,  358.                                                ^^H 

prininry  wnincs,  BS, 

-tolcns.  4<K).  301.                                           ^^^| 

KsoFvino],  421. 

-iircii,  325.  326, 

Pnuvian  blue,  5. 

-un-iw.  Alk)-I-,  325. 
Thiophcn,  338.  ^o^goi. 

Tc«t«  f«r  Aldehvoles,  136,  137. 

unilin*,  37U. 

-carlioxvlie  aptd,  a-,  501. 

carbonyl,  132. 

^-,"501. 

ol  purity,  32. 

-ki'loiww,  SOI. 

lleUn-«cct")'lwii!eli«»rl)oxvlic  arid,  207. 

-pht'nol,  .W2. 

-alkyUmnioiiiiim  indidi-e,  S3,  M. 

-iiulnhonii^  acid,  500.  SOI. 
Thiiip  ifiiiiii-,  502. 

-Latiic  sdJ«,  2(Jfl.  210. 

•tiruiiio-Fthatie,  47&. 

hvdRicltlciridc.  a02. 

-fluorcaceiii,  421. 

'ITiioscn,  499. 

-mcthaac,  170,  318. 

Thvniol,  S'33. 

^           -thloro-bpnsotrielikiride,  408. 

r                -ethylene,  17.5 

'               -mrth.'ini!,  170,  173,  318. 

TicKLK,  3<H. 

TiRlic  jwid,  361. 

Tin  mom.  AsvmniMfip,  95, 

-quinonc.  414. 

Tood-tlool,  28tl. 

-docano.  42. 

Talon,  41)8. 

-hydric  nlrohoU,  1H3,  184. 

Tolui-np,  343.  351 ,  353-354.  348,  am, 

-hydm-l»imw.-nr,  3fifl, 

3S3.  3^.  425,  4»<>.                                  ^ 

'ii-niiphlhytikiiiini.',  47S. 

-eiiliiiiotiaiiiide,  o-,  42>i.                               ^^^^| 

,9-1111  [ih  I liy Inn liiir.  477,  178. 

-tnilpl  1(11  lie  acid,  o-*  '12J.                              ^^^^| 

■pjrroK-,  liW.  M7, 

ToloK-  ivcid,  p-,  452.                                         ^^^^| 

-hj-drosysti-Arif  .'•irid.  167. 

•4DMhyl  Ammonium  hydroxide,  S6. 

arida.  3S7.                                                        1     ^^H 

Hliu'minolnpUitriyl-niridiiut,  463. 

Tduiilini>.  ni;  371.                                           ^^H 

-nuthsiip.      Sw  leuamialachiU- 

o-.  370.  405,                                                   ^^H 

preo«. 

p-.  370.  371 ,  465.                                           ^^H 

HMCcinic  arid,  211. 

tivdiVN-lilorJite,  473.                                   ^^^^| 

-uric  scid.  3^1. 
-metKylcnt^  bromide,  340. 

Ti)lyjp)ii'tiylkrliin<-,  301,  479.                           ^^^H 

Tri-ai'ctorirnminr,  131).                                     ^^^^| 

de  rival  ives,  340. 

-arctyllicnicnc  (1:3:^0,350.                       ^^^| 

-dinminc,  186,  247. 

-ullcyl-|Jioipliiri(M,  92                                        ^^^^| 

-dicarWxylifl  **t*r,  340. 

1 

■eidphonium  iodide,  307.                       ^^^H 

H         SSA                                                    INDEX.                                             ^^^1 

^L        Tl*-Anitno-fl2id>cnxcnc,  41S,  410. 

Tri-plteiivl-fliloniinrltiaM',  4(17.         ^V^ 

^H               -b«iuco«,  -1 19. 

•nu-thanc,  371.  380.  •131, 465.  40S. 

^H                ■Iriplii-iiylcjirbtiKJ,  465. 

4fi7.                                     1 

^V             •ftntvli'Di',  145. 

-met!)  vl,  467.                             ^H 

^^             -bui(^  acids,  V\%,  309. 

iodiclt,  ia7-                             ^H 

^^^H       -b«Dtvbimiii<.',  Mh. 

jwmxidc,  4fi7.                            ^^n 

^^^M     -bronihyilrin,  iriO.  175,  )80,  208. 

-roeikni]in«  hydrochloride.    Seeaft-     , 

^^^^"^      -broiiio-aiiilin«,  3ti0. 

itinr-blue.                                  ^^Jl 

^F                -phimot,  Afil. 

•sti-^nrin,  182.                                    ^^H 

^P                  •tiropiinc,  I5S. 

.«ulplionrs.  140.                         ^^^^^M 

^H                  -rcsorcinot,  400. 

-Uii»-m-<?ialilFby(Ie,  140.         ^^^^^| 

^B              -mrluUlvlic  aiiJ.  ao6i  309. 

-nccioriR.  NO,                       ^^^^^| 

^K             -rhlorhvdrin.  |SU. 

-carbonate.  Hnriuni,  S18.          ^^H 

^1            -cbloro-ni-i-inl.  'Jlil,  25S. 

Polasoium,  318.                       ^^M 

^B                 •ftc^TAldcbvde,  17 1  r  asi'  3S>- 

-cnT\ie>mc  twiA,  318.             ^^^^^M 

^H                 -Aof-tic  ndil,  313,  313,  2I>2. 

-Tn<^thv\t^r,  314.                  ^^^^^H 

^P                 -^thv1i?m'.  I7S. 

-valenry  p(  caihon,  4C7.          ^^^^^^ 

■                  .|th<>nol.  ISK, 

IteiiK,    £iitc-iy>|i[ii-r  couple  ot  OuD-    1 

^1                  •purini*  12:  Qt  fO,  338. 

nmnr.  mid,  37,  144.                    ^^J 

^1            .<7stihydnR,  208. 

Tricoa&ne.  42.                                        ^^M 

^H            •elhyl-Ainine.  87. 

TricwiT.,  IS5.  202.  280.                  ^^^M 

^H               •nieUianc,  85. 

Tropir  nrid.  516,  £17.                  ^^^^^M 

^H                 -pbospliini:,  93, 

Trapinc,  T,i(\,  fil7.                        ^^^H 
Trvpxiu,  532.                             ^^^H 

^1            -hydric  alcohols,  170-183. 

Tubct  fumncc.  0.                        ^^^^H 

^H             -hydroxy-oridK.  134,  A'A^ 

Ttirk^v-rpd.  484.                           ^^^M 

^H                 -biMii^n^  (1 :2:3).     .'H'W  pffiviffotloL 

Turpfnline,  Oil  of,  387,  423,  4S>H^H 

^B                     tl^3;fl).     Sec  iMi>rvgiiieini>L 

Tyrosiae,  436,  522,  528-                   ^^M 

^H                -fliitarir  iM-ii).  2A2,  205,  37o-]7>. 

^^^H 

^H                -imbu^yric  acid,  2^. 

^^H 

^V           -iodbvilriii,  ISl. 

^H             -lev tfiliFxnii  Kil  lij'leti  e.       See    phtoro- 

Uadcouic,  42.                            ^^^^H 

^H                     glttcifutt. 

^M            -4nelhvl-«o<rtt«  acid,  211. 

Vndecyknc,  142.                          ^^^^ 

irndeevknic  Mid.  16)                               j 

^1               -acetyl  cltlorid<-,  1 7S. 

UnimnloMtbir  rrartitrtu,  lio,  263,  4Ci^^J 

H                 -Atninp,  82,  86.  S7,  15D,  IKI>.  216- 

Lnsaturaled  anda,  a3-,  218.             ^^H 

^^^^          4>n«i!np  (1   3:.i).     l^w  mf»itij{tti«. 

;}r-.  218.                                     ^m 
MonoliMic.  ini-lfl7,  400.           ^H 

^^^B         -ctubinol.  .^1.  so. 

^^B              kidiili-. 

iilfohols,  1AS-1H0,403.                    ^H 

^^^^          .cthylinrthain-.  48. 

■Idrlivili-.*.  DiK.  too.                 ^^^H 

^H                 -oxoDiiim  ioiiido.  307. 

dilwfr  nrid^.  201'3O7.             ^^^H 

^^^^B          -pti<i:i  )1iin(i  u\idir,  93. 
^^^H        -pyn<  iavt.    bet-  colMine*. 

halogen  roDipniindfl,  IS6.        ^^^^^H 

hvdnx'uri>un9,  141-165,  405.          ^^1 

^^^^F        -euci'iuic  ucid,  -ItJO. 

kvluni-^,  169,  170.                    ^^^M 

^f            iwtlivlme,  34a,  3-1 1 , 

Urfttr,  l.ithiiinn,  331.                  ^^^^H 

■                 broniido,  175,  176,  177,  IS6,  340, 

t^o<ltum.  :i.tl.                           ^^^H 

■                         422. 

hv(ini(p-n,  331.                                       ^ 

^H                 •carboxyljp  arid,  340. 

lIrwi,31B.  317.  5i9-3»J.  32'/-330.332.      ' 

^V                cyMiidf,  IW. 

EsUinatioo  of.  323.                        ^H 

H                 •9}  col,  177. 

!)>(>..  322.                                            ^H 
Mrthvl-.  322.                           .^^H 

■            -nltro-bciucDc  (1:3:  S).  414.  -t'S. 

■ 

-iso-,  322.                             ^^^1 

^1                 •bu(ytx>-lriic,  415. 

nitrnU'.  319,  330,  32L.            ^^^^^| 

H               -pbt>tiul  (1;2:4:(>).  Seepicrkoa^ 

o.\3la^t--.  322.                                  ^H 

■                   -luluvt»'  (1:2:4:«),451. 

Syrillx-oiH  of,  1.  3)o,  321.           ^^^^1 

^H                -tripbMivlmcth.ini',  JUS. 

Vtr-w,  Duilkyl-.  321                      ^^^H 

^H            -p1)(>ny)-:ifnmn.  3IU(,  373.  37S. 

L'nridM.    S?«  twid-vrtiita.         ^^^^^M 

^B               <carbinolcartK»ylic  acid,  420. 

Ureldo-ncidi.,  328.                       ^^^H 

INDEX. 


55S 


XTrethanea.  324. 
Urio  acid,  328-336. 
Urochloralic  acid,  253. 

V. 

Vacuum  distillation,  25,  26. 
Valency,  23. 
Valei^dehyde,  127. 
Valeric  acid,  104,  194, 222. 
Valero-lactonc,  213. 

-nitrile,  246. 
Vanilla,  343,  438. 
Vanillin,  438. 
Vapour  pressure,  16. 

density  determination,  13-16, 
Horn  ANN 'n  method,  16. 
Victor  Meter's  method,  14,  15. 
of  carbon,  21. 

tension  curves,  28. 
Vaseline,  40. 
Vegetable-bases,  514. 
Velocity  of  formation  of  tetraalkylam- 

monium  iodides,  S3,  S4. 
Vn-t-iQEH,  306. 
VineKat,  106. 
VinvT-acetic  acid,  168, 197. 

alcohol,  158,  159. 

bromide,  156,  158, 

chloride,  158. 

-ethylene,  160. 
Violunc  acid,  330. 
Vital  force,  1. 
VitelUn,  524. 

VOLHARD,  313. 

Volume-percentage  of  alcobol,  B6. 
Vulcanite,  318. 

W. 

Waduork,  316. 
"Waiden,  223,  305. 
Walker,  Jaueb,  320. 
Walker,  Jamieson,  450; 
Wallach,  453,  454. 
Weioel,  24. 
Whty,  273. 
White  lead,  108. 

WlLTARTH,  8. 


Williauson's  etber  syntheoSi  73,  73. 
Wine,  55. 

Spirits  of,  56. 
Winkler,  94. 
Wrrr,  416, 

WOhler,  1,  2.  311,  320,  321. 
Wood-paper,  288. 

-ruff,  437. 

-spirit,  53,  57, 140. 

-Ur,  53. 
WiJHTZ,  312. 

X. 

Xanthate,  Cupric,  310. 

Cuprous,  319. 

Potassium,  318. 
Xanthic  acid,  319. 
Xanthine,  331,  333,  333-335,  625. 

bases,  526. 
Xantho-chelidonate,  Ethyl,  302. 

-chelidonic  acid,  302,  303. 

-protein-reaction,  533,  625,  527. 
Xylene,  m-,  354,  446. 

0-,  354. 

p-,354. 

-fiulphonic  acids,  354. 
Xylenes,  35a-354i  371,  387,  499. 
Xylic  acids,  387. 
Xylidines,  371. 
Xylitol,  183,  184,  259,  262. 
Xylonic  acid,  262. 
Xylose.  as9.  ^63,  363,  264,  270. 
Xylylene  bromide,  o-,  471. 

chloride,  o-,  436. 

Y. 

Yeast,  280,  281 
-cells,  53,  379,  380. 

Z. 

Ztnc-alkyls  or  alkides,  95,  128. 

-copper  couple,  37,  144 

-ethyl  or  etnide,  95. 

-methyl  or  methide,  93,  178. 

-propyl  or  propide,  95,  101. 
Zymase,  280. 


* 


^'* 


r