36 
Isatropylcocaine. 
Am.  Jour.  Pharm. 
Jan.,  1889 
(C9H702)2Ba,  is  crystalline,  and  readily  soluble  in  water.  The  calcium, 
copper  and  silver  salts  are  soluble  in  water.  The  ethyl-  and  methyl- 
derivatives  are  very  readily  formed  when  hydrogen  chloride  is  passed 
into  a  solution  of  the  acid  in  the  corresponding  alcohol.  The  ethyl  salt, 
C9H7Et02,  is  insoluble  in  ammonia  and  sparingly  soluble  in  alcohol, 
from  which  it  crystallizes  in  needles  melting  at  146°.  Methyl  y-isa- 
tropate,  09H7MeO2,  crystallizes  in  plates  or  needles,  melts  at  174°,  and 
distils  at  about  300°  with  very  slight  decomposition,  but  has  no  constant 
boiling  point.  A  vapor-density  determination  in  anthracene  va- 
por showed  that  it  is  at  first  polymeric,  and  is  only  completely 
transformed  into  the  simple  molecule  after  about  half  an  hour's  heating. 
3-lsatropic  acid,  C9H802,  forms  about  one-third  of  the  residue.  It 
is  more  easily  soluble  in  water  than  the  f-acid,  and  melts  at  206°. 
Neither  this  nor  the  ^-acid  yields  benzaldehyde  when  oxidized  with 
potassium  permanganate  or  chromic  acid.  An  aqueous  solution  of 
the  ammonium  salt  gives  precipitates  with  calcium  chloride,  mercuric 
chloride,  and  copper  acetate.  The  barium  salt,  (C9H702)2Ba,  is  spar- 
ingly soluble  in  water.  The  silver  salt,  C9H702Ag,  is  amorphous, 
but  becomes  crystalline  when  boiled  with  water.  The  ethyl  salt, 
C9H7Et02,  is  a  viscid  oil ;  it  has  no  constant  boiling  point,  but  after 
boiling  for  a  long  time  it  distils  at  264-270°,  and  condenses  to  a  color- 
less, mobile  oil.  The  methyl  salt,  C9H7Me02,  crystallizes  from  dilute 
alcohol  in  prisms  or  needles,  melts  at  76°,  and  is  readily  soluble  in  all 
solvents  except  water.  A  vapor-density  determination  in  anthracene 
vapor  showed  that  it  is  at  first  polymeric,  but,  the  transformation  into 
simple  molecules  takes  place  much  more  quickly  than  is  the  case  with 
the  corresponding  salt  of  the  ^-acid. 
The  acids  described  above  are  very  similar  in  appearance  and  solubil- 
ity to  a-isatropic  acid  (Lossen,  Annalen,  cxxxviii,  235),  /3-isatropic  acid 
(Fittig,  Annalen,  ccvi.,  34),  and  the  isatropic  acids  which  the  author 
has  previously  obtained  from  atropine,  but  they  are  not  identical  with 
any  of  these  compounds.  /9-Isatropic  acid  seems  to  be  formed  when 
hydrogen  chloride  is  passed  into  a  methyl  alcoholic  solution  of  a-isa- 
tropic acid.     Methyl  ft-isatropate  melts  at  91°. 
The  molecular  weight  of  ^-isatropic  acid,  methyl  and  ethyl  d-isatro- 
pate,  and  methyl  and  ethyl  f-isatropate  was  determined  by  Raoult's 
method  in  glacial  acetic  acid  solution,  and  in  all  cases  the  results 
agreed  for  the  molecular  formulae  given  above ;  the  salts  are  all  repre- 
cipitated  unchanged  when  water  is  added  to  the  glacial  acetic  acid  solu- 
