Am.  Jour.  Ptaarm. 
June,  1908. 
Chemical  Examination  of  Ipomcea  Purpurea. 
281 
An  aqueous  solution  containing  1-7680  grammes  of  substance  in 
25  c.c.  gave  aD  —  40  47'  in  a  1  dcm.  tube,  whence  [a]D  —  67. 630. 
Treatment  with  Dilute  Sulphuric  Acid. — A  quantity  (25  grammes) 
of  the  above-described  material  was  dissolved  in  250  c.c.  of  5  per 
cent,  aqueous  sulphuric  acid,  and  the  solution  heated  for  about  four 
hours  in  a  reflux  apparatus.  It  was  then  distilled  with  steam,  and 
the  distillate  extracted  with  ether,  when  a  very  small  quantity  of  a 
neutral  oil  was  obtained,  which  was  similar  in  character  to  that 
afforded  by  the  treatment  of  the  alcohol  extract  of  the  original 
resin  with  dilute  sulphuric  acid.  After  extraction  with  ether,  the 
distillate  still  contained  a  small  quantity  of  acid  which  was  converted 
into  a  barium  salt,  and  this  gave  reactions  indicating  the  presence 
of  formic  and  butyric  acids.  The  liquid  remaining  in  the  distilla- 
tion flask,  after  the  removal  of  the  volatile  substances  by  steam, 
and  being  allowed  to  cool,  contained  a  considerable  quantity  (5-5 
grammes)  of  a  solid  crystalline  product,  part  of  which  was  in  the 
form  of  a  brownish  cake.  It  was  therefore  extracted  with  ether, 
the  ethereal  solution  dried,  and  the  solvent  removed.  The  product 
thus  obtained  was  dissolved  in  alcohol,  the  solution  mixed  with 
purified  sawdust,  and,  after  thoroughly  drying  the  mixture,  it  was 
extracted  successively  in  a  Soxhlet  apparatus  with  {a)  light  petro- 
leum and  {b)  ether. 
(a)  Petroleum  Extract. — This  liquid  deposited  a  small  amount  of 
a  crystalline  substance  in  the  form  of  handsome  rosettes,  which  were 
associated  with  a  little  oily  matter.  After  the  complete  removal  of 
the  solvent,  the  substance  was  crystallized  from  50  per  cent,  alcohol, 
and  finally  from  a  large  volume  of  hot  water.  It  was  thus  obtained 
in  handsome,  colorless  needles,  me  lting  at  69-700  C,  and  on 
analysis  gave  the  following  result  : 
0-0676  gave  0-1646  C02  and  00670  H20.  C  —  66-4;  H  =  n-o. 
C12H2403  requires  C  =  66  6;  H  =  ii-i  per  cent. 
The  silver  salt  of  the  acid  was  also  prepared  and  analyzed. 
0-2042  of  salt  gave  on  ignition  00678  Ag.  Ag  =  33*2. 
C12H2303Ag  requires  Ag  =33*4  per  cent. 
The  above-described  substance  is  thus  seen  to  agree  in  composi- 
tion with  a  hydroxylauric  acid. 
A  hydroxylauric  acid  has  previously  been  obtained  by  Hoehnel1 
1  Archiv  der  Pharm.,  1896,  234,  p.  670. 
