Amju'ne?i908?rm'}     Chemical  Examination  of  Ipomcea  Purpurea.  275 
In  order  to  ascertain  whether  ipurolic  acid  could  be  distilled,  a 
small  quantity  (5  grammes)  of  it  was  heated  in  a  distillation  flask 
under  a  pressure  of  15  mm.  During  the  operation  witer  was  elimin- 
ated, and  between  240  and  2500  C.  the  greater  portion  passed  over  as 
a  viscid  yellow  oil,  the  temperature  being  finally  increased  to  2800  C. 
at  15  mm.  As  the  oily  product  did  not  solidify,  it  was  dissolved 
in  ether,  and  the  ethereal  liquid  extracted  with  a  solution  of  sodium 
carbonate.  On  subsequently  removing  the  ether  about  0-5  gramme 
of  a  non-acidic  substance  was  obtained,  whereas  the  sodium  carbon- 
ate had  extracted  about  4  grammes  of  acidic  substance.  Both  these 
products  were  unsaturated,  but  their  analysis  and  the  determina- 
tion of  their  iodine  values  showed  them  to  be  complex  mixtures 
which  did  not  permit  of  further  examination. 
Methyl  Ipurolate,  C13H25(OH)2.  C02CH3. 
Five  grammes  of  ipurolic  acid  were  dissolved  in  hot  methyl  alco- 
hol, and  dry  hydrogen  chloride  passed  into  the  solution  until  it  was 
saturated.  The  solution  was  then  poured  into  water,  when  the  ester 
separated  as  a  white  precipitate,  and  was  extracted  by  means  of 
ether.  The  ethereal  liquid  was  washed,  first  with  a  solution  of 
sodium  carbonate  to  remove  any  unchanged  acid,  and  then  with 
water,  after  which  it  was  dried  with  calcium  chloride,  and  the  ether 
removed.  A  crystalline  mass  was  thus  obtained,  which  was 
recrystallized  from  dilute  methyl  alcohol,  when  the  ester  separated  in 
the  form  of  fine  needles,  melting  sharply  at  68-690  C.  On  analysis 
it  gave  the  following  result : 
0-1042  gave  0-2500  C02  and  0-1038  H20.    G-=  65-4  ;  H  =  n  1. 
C15H30O4  requires  C  =  657  ;  H  =  10-9  per  cent. 
For  the  purpose  of  ascertaining  the  presence  of  hydroxyl  groups 
in  ipurolic  acid,  an  attempt  was  made  to  prepare  its  acetyl  and  ben- 
zoyl derivatives.  The  products,  however,  could  only  be  obtained 
in  the  form  of  thick  syrups,  which  were  not  suitable  for  analysis. 
Di-phenylurethane  of  Methyl  Ipurolate,  C13H25  (O-CONH  C6H5)2C02 
CH3. — Two  grammes  of  methyl  ipurolate  were  heated  with  an  excess 
of  phenyl  w^cyanate  in  a  sealed  tube  in  a  water-bath  for  about  eight 
hours.  After  being  allowed  to  cool,  the  product  was  shaken 
with  light  petroleum,  when  a  solid  was  precipitated.  This  was  dis- 
solved in  a  small  quantity  of  ether  and  cooled  to  —  io°  C,  when  a 
