﻿62 
  Drushel 
  and 
  Felty 
  — 
  Preparation, 
  etc., 
  of 
  

  

  necessary 
  to 
  prepare 
  it 
  in 
  the 
  laboratory. 
  In 
  its 
  preparation 
  

   from 
  aniline 
  a 
  few 
  important 
  points 
  must 
  be 
  observed 
  in 
  order 
  

   to 
  obtain 
  the 
  final 
  product 
  in 
  pure 
  condition 
  and 
  in 
  good 
  yield. 
  

   Several 
  modifications 
  were 
  introduced 
  into 
  the 
  processes 
  

   described 
  in 
  the 
  literature, 
  increasing 
  the 
  yield 
  and 
  improving 
  

   the 
  purity 
  of 
  the 
  products. 
  Parabromacetanilide 
  was 
  pre- 
  

   pared 
  from 
  aniline 
  by 
  a 
  modification 
  of 
  Hubner's* 
  method. 
  

   One 
  mol 
  of 
  aniline, 
  one 
  mol 
  of 
  acetic 
  anhydride 
  and 
  two 
  mols 
  

   of 
  glacial 
  acetic 
  acid 
  were 
  mixed 
  and 
  allowed 
  to 
  stand 
  until 
  

   cold. 
  To 
  this 
  mixture 
  one 
  mol 
  of 
  bromine 
  was 
  added 
  in 
  small 
  

   portions 
  with 
  cooling. 
  When 
  the 
  last 
  portion 
  of 
  bromine 
  was 
  

   added 
  crystals 
  began 
  to 
  separate 
  out 
  and 
  the 
  mixture 
  was 
  

   immediately 
  poured 
  into 
  a 
  liter 
  of 
  cold 
  water 
  with 
  stirring. 
  

   On 
  recrystallizing 
  the 
  precipitate 
  from 
  alcohol 
  snow 
  white 
  

   j?-bromacetanilide 
  was 
  obtained 
  in 
  almost 
  quantitative 
  yield. 
  

   The 
  ^>-bromacetanilide 
  was 
  converted 
  to 
  ^>-bromaniline-«9-sul- 
  

   phonic 
  acid 
  by 
  heating 
  at 
  170°-180° 
  with 
  the 
  theoretical 
  

   amount 
  of 
  sulphuric 
  acid 
  of 
  specific 
  gravity 
  of 
  2'0 
  in 
  an 
  oil 
  

   bath 
  until 
  the 
  acetic 
  acid 
  was 
  completely 
  eliminated, 
  instead 
  of 
  

   heating 
  the 
  mixture 
  directly 
  over 
  a 
  free 
  flame 
  as 
  suggested 
  by 
  

   Kreis.f 
  In 
  this 
  way 
  charring 
  was 
  entirely 
  avoided 
  and 
  the 
  

   yield 
  was 
  practically 
  quantitative. 
  The 
  method 
  of 
  removing 
  

   the 
  bromine 
  from 
  ^-bromaniline-6>-sul 
  phonic 
  acid 
  suggested 
  by 
  

   KreisJ 
  was 
  also 
  modified 
  in 
  an 
  important 
  point, 
  shortening 
  the 
  

   time 
  required 
  and 
  improving 
  the 
  quality 
  of 
  the 
  product. 
  

   Under 
  the 
  conditions 
  described 
  by 
  Kreis 
  boiling 
  with 
  zinc 
  dust 
  

   in 
  alkaline 
  solution 
  for 
  nine 
  hours 
  was 
  found 
  insufficient 
  to 
  

   remove 
  completely 
  the 
  bromine 
  from 
  60grm. 
  of 
  ^?-bromaniline- 
  

   tf-sulphonic 
  acid. 
  A 
  60 
  grm. 
  portion 
  of 
  this 
  sulphonic 
  acid 
  was 
  

   boiled 
  for 
  three 
  hours 
  with 
  600 
  cm3 
  of 
  sodium 
  hydroxide 
  solution 
  

   containing 
  15 
  grm. 
  excess 
  of 
  sodium 
  hydroxide 
  and 
  25 
  grm. 
  of 
  

   zinc 
  dust. 
  At 
  the 
  end 
  of 
  three 
  hours 
  a 
  titration 
  of 
  5 
  cm3 
  of 
  the 
  

   solution 
  showed 
  that 
  over 
  70 
  per 
  cent, 
  of 
  the 
  bromine 
  had 
  

   been 
  removed 
  from 
  the 
  benzene 
  ring. 
  Fifteen 
  grams 
  more 
  of 
  

   sodium 
  hydroxide 
  and 
  10 
  grm. 
  of 
  zinc 
  dust 
  were 
  now 
  added 
  

   and 
  the 
  boiling 
  continued 
  for 
  two 
  and 
  a 
  half 
  hours, 
  when 
  a 
  

   titration 
  showed 
  that 
  the 
  bromine 
  was 
  removed 
  quantitatively 
  

   from 
  the 
  benzene 
  ring. 
  In 
  other 
  particulars 
  the 
  method 
  was 
  

   carried 
  out 
  as 
  described 
  by 
  Kreis, 
  obtaining 
  a 
  good 
  yield 
  of 
  

   pure 
  c-amidobenzenesulphonic 
  acid. 
  

  

  The^?-benzenedisulphonic 
  acid 
  was 
  prepared 
  from 
  its 
  purified 
  

   potassium 
  salt 
  by 
  the 
  procedure 
  described 
  for 
  the 
  m-benzene- 
  

   disulphonic 
  acid. 
  The 
  obenzenedisulphonic 
  acid 
  was 
  prepared 
  

   directly 
  from 
  its 
  purified 
  barium 
  salt 
  by 
  the 
  action 
  of 
  the 
  theo- 
  

  

  * 
  Hubner. 
  Ann. 
  d. 
  Chem., 
  ccix, 
  355, 
  1881. 
  

   | 
  Kreis, 
  Ann. 
  d. 
  Chem., 
  cclxxxvi, 
  377, 
  1895. 
  

   {Ibid., 
  cclxxxvi, 
  379, 
  1895. 
  

  

  