Am'juiu/,'i9oiarm"}     Developments  in  Organic  Compounds.  331 
was  the  nucleus,  antipyrin  ,being  a  phenyl  1  —  dimethyl  2,  3  — 
pyrazolon  5. 
CH,N 
CH3C 
N  .  C6H5 
CO 
LH 
Tolypyrin  resulting  through  the  introduction  of  a  methyl  group 
possesses  a  more  irritating  action,  4  grammes  bring  equivalent  to  5 
to  6  of  antipyrin. 
The  only  active  competitor  of  antipyrin  belonging  to  this  series 
was  found  in  Pyramidon,  a  di  methyl-amido-antipyrin  which  is  three 
times  as  active  as  antipyrin 
N  .  C6H5 
CHoN  ,/X  CO 
CH3C 
C(CH, 
ANILIN  DERIVATIVES. 
The  accidental  discovery  of  the  antipyretic  and  anti-neuralgic 
properties  of  acetanilid  led  to  its  study  and  subsequent  unlimited 
application  in  the  preparation  of  innumerable  medicinal  derivatives. 
The  introduction  of  acid  radicals  in  place  of  a  hydrogen  of  the  amido 
group  of  a  base  results  m  the  diminution  of  its  toxic  action  on  the 
ground  that  the  substance  has  become  more  resistive  to  the  decom- 
posing action  of  the  body  fluids;  hence  acetanilid  C6H5NHCH3CO 
represents  the  toxic  characters  of  anilin  but  in  a  milder  degree,  its 
action  being  that  of  anilin  in  a  weak  and  protracted  condition. 
Benzanilid  C6H5NHC6H5CO  splits  up  with  difficulty  and  slowly 
in  the  system,  hence  its  action  is  milder  than  that  of  acetanilid, 
Salicylic  anilid  fails  to  break  up,  hence  is  without  action. 
PARA-AMIDO-PHENOL  DERIVATIVES. 
With  the  experience  of  acetanilid  and  its  derivatives  synthetic 
chemists  made  systematic  efforts  to  build  up  a  substance  which 
should  represent  the  antipyretic  and  antineuralgic  properties  of 
acetanilid  without  its  unpleasant  side  effects  and  action  on  the 
hemoglobin  of  the  red  blood-corpuscles. 
