548 
The  Synthesis  of  Alkaloids. 
Am.  Jour.  Pharm. 
Nov.,  1889. 
dation  of  quinine,  cinchonine,  quinidine,  cinchonidine  and  papaver- 
ine with  potassium  permanganate  solution,  while  a  second  of  these 
pyridine-tricarboxylic  acids  is  produced  by  the  oxidation  of  berberine 
with  nitric  acid. 
The  acids  of  the  pyridine  series  are  capable  of  furnishing  very 
interesting  addition  products,  the  constitution  of  which  is  analogous  to 
that  of  the  betaine  of  the  beet  juice.  These  betaines  of  the  pyridine- 
carboxylic  acids  have  assumed  quite  an  importance  since  chemists  have 
recognized  the  close  relationship  they  bear  to  some  of  the  natural  alka- 
loids. Of  the  pyridine  series,  Hantzsch  has  prepared  the  betaines  of  ni- 
cotinic, picolinic  and  collidine-carboxylic  acids,  and  Poser  that  of  cin- 
chomeronic  acid.  Quite  recently  Jahns  has  shown  that  the  betaine  of 
nicotinic  acid  is  identical  with  trigonelline,  the  alkaloid  of  Trigonella 
foenum  grceoum,  and  that  the  betaine  of  cinchomeronic  acid,  prepared 
synthetically  by  Roser,  is  identical  with  the  apophyllic  acid  obtained 
by  the  oxidation  of  cotarnine,  one  of  the  decomposition  products  of 
narcotine. 
Another  series  of  these  acid  derivatives  of  pyridine  have  the  pyri- 
dyl  residue  C5H4N,  replacing  an  H  atom  in  the  formula  of  well- 
known  acids.  Thus,  ,3-pyridine-a  lactic  acid  results  along  with  tri- 
methylamine  when  the  natural  alkaloid  pilocarpine  is  decomposed  by 
prolonged  heating  with  water.  Pilocarpidine,  which  occurs  along 
with  pilocarpine  in  jaborandi  leaves,  is  /?-pyridine-a  dimethylamido- 
propionic  acid.  Pilocarpidine  has  been  made  synthetically  by  Hardy 
and  Calmels ;  and  this  by  the  action  of  methyl  iodide  and  caustic 
alkali,  followed  by  silver  permanganate,  has  produced  pilocarpine 
itself.  The  alkaloid  jaborine,  which  accompanies  pilocarpine  in  jabo- 
randi leaves,  can  be  obtained  as  a  decomposition  product  from  the 
latter. 
The  action  of  ammonia  upon  certain  acids  found  in  the  vegetable 
kingdom,  such  as  chelidonic  and  meconic  acids,  has  been  found  to  pro- 
duce acids  recognized  as  pyridine  derivatives.  Thus,  comanic  acid 
C6H404,  derived  from  meconic  acid,  is  changed  by  ammonia  into  an 
oxypicolinic  acid,  while  comenic  acid  C6H405,  from  the  same  source, 
yields  dioxypicolinic  acid ;  and  chelidonic  acid  C7H406,  which  accom- 
panies the  alkaloids  chelidonine  and  sanguinarine  in  Chelidonium 
majus,  yields  an  oxypyridine-dicarboxylic  acid. 
To  the  tetrahydro  derivatives  of  the  higher  homologues  of  pyri- 
dine belong  ecgonine  and  its  products,  of  which  latter  cocaine,  the  alka- 
