Ajan^yPi92itn'}     Thymol  and  Carvacrol  Problems.  11 
posed  on  addition  of  water  or  acids  liberating  carvacrol.  On  analysis 
by  conversion  into  carbonate  it  gave  the  value  for  sodium  of  13.64 
per  cent.   The  calculated  value  is  13.36. 
In  the  laboratory  the  sodium  derivative  of  both  carvacrol  and 
thymol  were  prepared  in  heptane  and  in  ether.  About  ten  grammes 
of  the  phenols  were  dissolved  in  100  Cc.  heptane  and  metallic  sodium 
added.  Carvacrol  reacted  with  a  slow  evolution  of  hydrogen  and 
a  closely  adherent  coat  formed  on  the  metal.  This  liquid  became 
reddish  in  color  and  a  layer  of  the  flaky  precipitate  adhering  to  the 
glass  assumed  an  intense  blue  color.  The  bulk  of  the  precipitate 
was  of  a  pale  color.  Thymol  caused  an  immediate  more  lively 
evolution  of  hydrogen  and  the  temperature  rose  to  30-400.  The 
solution  remained  clear  for  a  time  and  as  soon  as  the  first  turbidity 
of  crystals  appeared  the  action  began  to  slow  down  at  once.  This 
may  be  attributed  to  the  fact  that  the  phenols  form  complexes  with 
the  phenolates,  the  alkali  derivatives. 
Thus  in  1903  Gentsch  9  obtained  a  patent  on  a  process  for  ob- 
taining double  compounds  of  phenols  with  phenol  alkali  derivatives. 
These  compounds  result  on  treating  the  phenols,  with  or  without  an 
indifferent  solvent,-  with  alkali  carbonates,  caustic  alkalis,  or  phenol 
alkali  compounds,  and  were  used  for  separation  and  isolation  of 
phenols  from  mixtures.  These  crystalline  derivatives  may  be 
washed  and  separated  by  progressive  and  differential  solubility. 
Phenol  forms  a  compound  of  the  type  C6H5OK,3C6H5OH,  crystal- 
lizing from  benzene  or  alcohol.  Cresol  also  forms  a  complex.  The 
existence  of  such  a  soluble  complex  may  explain  the  effect  of  the 
addition  of  more  thymol  which  dissolves  the  precipitate  first 
formed. 
The  action  of  sodium  on  the  phenols  in  ether  was  different  from 
that  in  heptane.  Ether  which  had  stood  over  sodium  was  employed 
as  a  reaction  medium  using  about  the  same  quantities  as  for  hep- 
tane. Sodium  was  added  to  the  flask  attached  to  a  reflux  condenser. 
Carvacrol  developed  the  reddish  color  immediately  and  the  action 
was  so  vigorous  that  the  ether  boiled.  The  sodium  compound  began 
to  crystallize  out  as  slender  colorless  prisms  about  a  centimeter  long. 
They  were  filtered  off  and  placed  in  a  lime  desiccator  where  they 
became  opaque  and  the  edge  became  rounded,  and  the  faces  assumed 
a  vitreous  appearance.    They  quickly  turned  brown. 
9  Gentsch,  D.  R.  P.  No.  156  (1903),  p.  761. 
