496 
New  Essential  Oils. 
{ 
Am.  Jour.  Pharna, 
October,  1909. 
which  attached  to  all  these  fractions  is  ascribable  to  the  presence  of 
isopulegol.  This  isopulegol  obviously  owed  its  existence  to  the 
action  of  acids  upon  the  citronellal. 
Further,  in  the  portions  of  the  oil  boiling  between  75  °  and  103 0 
(5  mm.  press.)  we  discovered  an  alcohol  of  a  rose-like  odor,  which 
was  ascertained  to  be  d-citronellol.  For  the  purpose  of  identifica- 
tion the  fractions  were  treated  in  the  well-known  manner  with 
phthalic  anhydride.  The  citronellol,  separated  by  saponification 
from  the  solution  of  the  sodium  salt  of  the  acid  phthalic  ester  and 
distilled  over  with  water  vapor,  possessed  the  following  constants : 
b.  p.  930  to  950  (5  to  6  mm.  press.),  dis0  0.8732,  aD  +  20  14',  nD2QO 
1.46288.  The  silver  salt  prepared  from  the  free  acid  phthalate,  after 
being  recrystallized  from  benzene  and  methyl  alcohol,  showed  the 
characteristic  melting  point  for  this  salt  (1250)  and  the  theoretically 
required  silver  content : 
When  the  original  oil  was  treated  with  highly-diluted  soda 
liquor  it  proved  to  contain  an  oi1y  acid  of  a  high  b.  p.  as  well  as 
traces  of  a  phenol.  In  order  to  separate  these  two  the  oil,  after 
being  recovered  from  the  soda  liquor,  was  treated  with  carbonate  of 
soda  solution.  The  acid  which  had  separated  from  the  carbonate 
solution  on  acidulation  may,  however,  not  be  a  uniform  one,  as 
might  be  concluded  from  its  b.  p.  and  its  behavior  as  detailed  below. 
Apart  from  an  unimportant  first  runnings  (b.  p.  1150  to  125 °,  5-6 
mm.  press.)  it  boiled  at  1250  to  131  °.  Its  other  constants  were  as 
follows:  b.  p.  2570  to  2630  at  normal  press.,  d  0  0.9394,  ai}  +  5°  2', 
nD20o  1.45611.  These  properties,  and  the  silver  content  as  ascer- 
tained by  analysis  of  its  silver  salt  recrystallized  from  water,  indicate 
citronellic  acid  C10H18O2 : 
0.2774  g.  sbst. :  0.0727  g.  Ag. 
Found : 
Ag  26.21  per  cent. 
Calc.  for  C18H21Ag04: 
26.23  per  cent. 
0.3079  sbst. :  0.1 196  g.  Ag. 
Found : 
Ag  38.84  per  cent. 
Calc.  for  C10H17AgO2 : 
38.77  per  cent. 
In  order  to  identify  the  acid  more  closely  recourse  was  had  to  the 
amide  of  citronellic  acid,  m.  p.  81 0  to  820.  For  its  preparation,  the 
acid  was  first  converted  into  the  chloride  (b.  p.  122 0  to  125 °,  6  mm.) 
