Am.  Jour.  Phariu. 
Sept.,  1893. 
Pennyroyal.  Oil. 
419 
as  to  the  identity  of  this  compound  with  the  pulegoneoxime 
obtained  by  Beckmann  and  Pleissner,1  from  the  oil  of  Mentha  Pule- 
gium,  the  Spanish  Pennyroyal  oil.  Its  action  toward  polarized 
light  also  agrees  very  well  with  that  of  the  pulegoneoxime  of 
Beckmann  and  Pleissner.2 
S  1-2390  grams 
L  (ether)  35"5i44  grams 
p.  3-48  p.  c 
t.  200  C 
d.  0751 
1.  1  d.m. 
«  -  2'33° 
[a]D  =  -SS77 
Beckmann  and  Pleissner  found  [«]D  ==  —  83-44. 
THE  BENZOYLESTER  OF  PULEGONEOXIME. 
Beckmann  and  Pleissner3  prepared  a  benzoylester  by  adding  to 
two  parts  of  the  pulegoneoxime  a  solution  of  two  parts  of  benzoyl- 
chloride  in  ten  parts  of  ether.  After  the  ether  has  evaporated,  the 
residue  is  treated  with  sodium  hydroxide  in  the  cold,  when  the 
ester  will  congeal  to  a  white  plastic  mass.  This  can  be  crystallized 
from  dilute  alcohol,  or  from  a  mixture  of  benzene,  and  that  fraction 
of  petroleum  benzine  boiling  at  about  500  C.  The  benzoylester  of 
Beckmann  and  Pleissner4  is  stated  to  have  been  obtained,  in  colorless 
needle-shaped  crystals,  melting  at  137-1380  C,  with  the  generation 
of  gas. 
The  benzoylester  obtained  from  one  gram  of  the  oxime  crystal- 
lized only  in  part  in  needle-shaped  crystals,  which  were  only 
partially  soluble,  in  the  mixture  of  benzene  and  petroleum  benzin, 
or  alcohol,  or  ether.  The  melting  points  ranged  from  1370  C. 
upward.  The  crystals  obtained  from  the  mixture  of  benzene  and 
petroleum  benzin  melted  at  141 0  C.  Those  insoluble  in  this  mix- 
ture, even  after  heating  for  several  hours  on  a  water-bath,  melted  at 
175  0  C.    This  discrepancy  of  the  benzoylester  can  be  explained,  by 
1  Ann.  d.  Chem.,  Bd.  262,  p.  7. 
2  Ibidem,  p.  8. 
3  Ibidem,  p.  10. 
4  Ibidem,  p.  10. 
