254 
Experiments  on  Strychnine. 
f  Am.  Jour.  Pharm. 
(      May,  1885. 
Monobromostrychnine  forms  a  hydrochloride,  which,  on  evaporation, 
yields  gelatinous  masses,  and  these  soon  set  into  silky  needles. 
Having  observed  that  by  the  addition  of  four  equivalent  propor- 
tions of  bromine  to  solutions  of  strychnine  practically  all  the  strych- 
nine is  thrown  down  as  the  resin  mentioned  by  Laurent,  I  was  led  to 
suspect  its  nature.  If  precipitated  at  about  40°,  it  can  be  secured 
easily  as  a  bright  yellow  powder,  which  sloAvly  evolves  bromine,  is 
insoluble  in  water  and  chloroform,  but  soluble  in  alcohol.  On  analysis, 
0*1262  gram  gave  0-1293  gram  of  AgBr,  equivalent  to  43*58  per 
cent,  of  Br.  It  is  therefore  dibromide  of  monobromostrychnine, 
C.jitl2i^^'^2^25B''2  (^^'hich  requires  41*8  per  cent,  bromine),  a  little 
contaminated  with  some  other  more  highly  l)rominated  substance. 
This  was  confirmed:  1.  By  the  fact  that  the  same  body  is  thrown 
down  on  adding  l)romine  to  solution  of  bromnstrychnine.  2.  That  by 
the  action  of  ammotiia,  it  is  changed  to  a  white  substance,  having  all 
the  properties  of  bromostrychnine.  A  specimen  of  bromostrychnine 
made  in  this  way  was  found  to  contain  21*17  per  cent,  of  bromine, 
theory  requiring  19*37.  This  is  what  would  be  expected  from  the 
above  facts. 
Dibvomostrychnine. — When  the  above  precijiitate  is  heated  with  its 
mother-liquor  for  some  hour.s,  it  presently  dissolves.  This  led  me  to 
hope  th  it  dibromostrychnine  was  formed  by  the  reaction  C2iH2iBr 
NA'Br,  =  G,iH.,Br,NA,HBr. 
Analyses  of  the  products  always  show  great  deficiency  of  bromine, 
so  there  is  no  doubt  that  oxidation  occurs.  Neither  did  I  succeed  in 
effecting  the  above  reaction  by  heating  the  dry  solid,  or  by  exposing 
it  to  sunlight.  If,  however,  solution  of  bromine  in  chloroform  is 
added  cautiously  to  a  solution  of  strychnine  in  the  same  liquid,  there 
is  not  much  precipitation  until  two  equivalents  of  bromine  have  been 
added.  After  that,  it  is  rapidly  precipitated,  probably  as  a  dibromide, 
analogous  to  that  above  described.  If  the  addition  of  bromine  is 
stopped  at  the  right  point,  and  the  solution  is  treated  with  alkali,  it 
gives,  on  evaporation,  a  resin-like  residue,  rather  easily  decomposed  by 
heat;  this  does  not  appear  to  be  crystalline.  Analysis  of  a  specimen 
showed  it  to  contain  35*3  per  cent,  of  bromine ;  so  probably  it  is 
dibromostrychnine  with  the  formula  C2iIl2oBr2N202,  which  requires 
32*5  per  cent.  Br,  contaminated  with  some  more  highly  brominated 
product.  Although  I  have  not  succeeded  in  its  purification,  I  hope 
it  will  prove  useful  in  some  future  work. 
