t$2  Manufacture  of  Chloramine— T.  {A%J°cu^9P^m' 
allowed  to  go  on  over  night  under  reflux  condenser  on  a  water-bath. 
The  oxychloride  is  then  distilled  off  in  vacuo  and  the  residue  put 
into  cold  water.  The  sulphonic  chloride  is  the  only  part  insoluble 
and  is  separated  by  filtration:  a  small  amount  of  oily  impurity  (o- 
and  m-sulphonic  chlorides)  can  be  pressed  out  from  the  solid  cake. 
The  yield  is  nearly  quantitative,  96-99  per  cent.  The  solid 
sulphonic  chloride  still  contains  small  amounts  of  0-  and  m-impuri- 
ties,  but  these  are  gradually  eliminated  in  the  later  stages. 
Preparation  of  Sulphonamide. — This  operation,  though  quite 
simple  in  theory,  causes  a  certain  amount  of  trouble  without  special 
apparatus.  The  alternative  methods  are  treatment  with  ammonium 
carbonate  on  the  water-bath  and  treatment  with  strong  ammonia 
solution.  The  latter  method,  if  properly  controlled,  is  decidedly  the 
more  satisfactory.  If  the  sulphonic  chloride  is  ground  to  a  fine 
powder  and  concentrated  ammonia  is  poured  upon  it,  a  violent  reac- 
tion begins  almost  at  once  and  the  liquid  boils.  In  this  way  con- 
siderable amounts  of  ammonia  are  driven  off  and  the  action  is  apt 
to  be  incomplete.  We  had  some  difficulty  in  procuring  vessels  in 
which  the  reaction  could  be  conveniently  carried  out  under  pressure, 
and  owing  to  the  impossibility  of  getting  special  vessels  made  which 
would  stand  the  action  of  a  hot  mixture  of  ammonia  and  ammonium 
chloride,  we  used  stoneware  ginger-beer  bottles  which  had  a  screw 
stopper  with  a  rubber  seating.  100  Gm.  of  sulphonic  chloride  could 
be  placed  in  each,  100  Cc.  of  0.880  ammonia  quickly  added  and  the 
stopper  screwed  in  firmly.  On  shaking  vigorously  the  action  began, 
and  as  soon  as  the  bottle  became  too  hot  to  hold  it  was  placed  in 
cold  water.  No  mishaps  occurred  and  the  yield  was  excellent,  the 
liquid  only  requiring  filtering  and  the  residue  washing  with  cold 
water.  The  mother  liquors  on  evaporation  give  small  amounts  of 
the  m-amide  but  very  little  else  besides  the  ammonium  chloride. 
Under  these  conditions  about  half  the  ammonia  taken  is  actually  used 
and  on  a  large  scale  the  unchanged  ammonia  could  be  recovered  by 
boiling  the  liquors.  The  yield  of  />ara-sulphonamide  is  94-97  per 
cent. 
Preparation  of  Chloramine-T. — The  conditions  for  the  con- 
version of  amide  to  chloramine  were  given  in  detail  by  Dakin,  one 
mol.  of  amide  being  dissolved  in  1.2  mols.  of  sodium  hypochlorite 
of  definite  concentration  and  the  chloramine  then  precipitated  by  the 
addition  of  strong  brine.  At  first  his  actual  proportions  were  used, 
but  it  was  found  to  be  unnecessary  to  use  brine.    If  the  amide  is 
