144  BFNZOLE  FROM  COAL-NAPHTHA. 
PURE  BENZOLE  FROM  COAL-NAPHTHA. 
By  A.  H.  Church. 
The  sulphite  of  phenyle  and  ammonium  C12H5,  NH4,  2  S03 
usually  called  sulphobenzolate  of  ammonium  yields  a  very  large 
proportion  of  pure  benzole  when  submitted  to  dry  distillation. 
The  hydrocarbon  thus  procured  can  hardly  be  distinguished 
from  the  benzole  obtained  by  heating  benzoic  acid  with  lime. 
Its  odor  is  ethereal,  almost  fragrant ;  and  its  boiling-point  is 
constant  at  80°-8.  A  chemist  well  acquainted  with  the  ordinary 
benzole  obtained  from  coal-naphtha,  to  whom  I  showed  a  speci- 
men of  the  benzole  thus  prepared  from  the  sulphobenzolate  of 
ammonium,  scarcely  recognised  it  as  the  same  substance,  so 
pleasant  was  its  odor. 
To  prepare  the  sulphobenzolate,  the  purified  benzole  of  com- 
merce is  dissolved,  with  the  aid  of  a  gentle  heat,  in  a  slight  ex- 
cess of  fuming  sulphuric  acid  ;  if  ordinary  oil  of  vitriol  be  em- 
ployed, a  much  larger  quantity  of  the  acid  is  required.  The 
acid  liquid,  after  having  been  heated  in  the  water-bath  for  some 
time,  is  allowed  to  cool,  and  then  diluted  with  water.  Commer- 
cial carbonate  of  ammonium,  together  with  some  ammonia  water, 
is  to  be  added  till  the  solution  is  slightly  alkaline.  The  whole 
is  now  evaporated  to  dryness  on  the  water-bath,  and  the  dry 
mass  exhausted  with  boiling  alcohol.  The  greater  part  of  the 
sulphate  of  ammonium  remains  in  the  residue.  The  alcoholic 
solution  of  the  sulphobenzolate  of  ammonium  is  to  be  transferred 
to  a  retort,  and  submitted  to  distillation.  When  all  the  alcohol 
has  distilled  over,  the  receiver  is  changed,  and  the  heat  raised. 
The  benzole  which  collects  in  the  receiver  is  accompanied  by 
small  quantities  of  solid  products  and  by  water.  From  these  it 
may  be  separated  by  the  addition  of  a  strong  potash-solution, 
and  the  removal  of  the  supernatant  oil  by  the  pipette.  The 
benzole  is  then  rectified  off  caustic  potash.  The  benzole  thus 
produced  is  perfectly  pure  ;  and  although  the  quantity  obtained 
is  not  very  large  yet  the  result  of  the  process  is  exceedingly  in- 
teresting to  the  chemist,  since  it  removes  all  doubt  concerning 
the  identity  of  the  benzole  from  coal-naphtha  and  similar  sources 
with  that  obtained  from  benzoic  acid. — Ohem.  News,  Dec,  31, 
1859. 
