210  Urethanes  of  Thymol  and  Carvacrol.    {ATul^h  mYm' 
Potassium  Nitrosothymol. — Nitrosothymol  dissolves  somewhat 
readily  in  potassium  hydroxide,  leaving  an  oil-like  film  on  the  sur- 
face. It  evaporates  leaving  a  bluish-green  mass  with  a  green  frac- 
ture and  not  well  crystalline.  It  forms  an  olive-green  powder. 
When  dissolved  in  absolute  alcohol,  it  begins  to  come  down  on  add- 
ing an  equal  volume  of  ether.  It  forms  a  bright  mass  of  almost 
malachite  green  with  a  bright  fracture.  It  is  stable  at  ioo°,  but 
decomposes  spontaneously  with  sulphuric  acid,  and  on  heating,  giv- 
ing a  bright  red  sublimate. 
0.4210  g.  lost  0.0334  g.  at  ioo° 
Li  0.2000  g.  gave  0.0756  g.  K2S04 
II.  0.2040  g.  gave  0.0772  g.  K2S04 
Found  Calcj  for  C10H]2NO2K 
Loss  at  1000,       7.93  p.  cj 
iH20  =  7-66  p.  c. 
Potassium  on  dried  basis  I.  18.42p.1c.  rS.oo  " 
II.  18.44  " 
It  was  recovered  in  91  per  cent,  yield  by  weight;  ter  Meer  20a 
prepared  the  alkali  compounds  of  nitrosophenol  itself  by  allowing  a 
solution  of  the  metal  in  absolute  alcohol  to  act  on  an  ether  solution 
of  the  nitrosophenol.  He  crystallized  his  products  from  water  and 
acetone  and  found  them  stable  towards  carbon  dioxide  in  aqueous 
solution.  The  ammonium  compound  was  unstable  and  could  not  be 
prepared  at  all. 
The  sodium  derivative  of  carvacrol  forms  the  most  readily, 
and  is  of  the  finest  appearance.  It  is  immediately  crystalline  by 
precipitation  from  ether  and  drys  as  a  splendid,  brown  maroon  pow- 
der. The  thymol  derivative  comes  out  amorphous  at  first,  but 
quickly  becomes  crystalline,  and  gives  needles  of  much  the  same 
color,  cementing  to  lumps  on  filtration  and  drying.  The  potassium 
compounds  give  aqueous  solutions  of  much  the  same  color,  but  blue 
solids  from  water  and  ether.  They  appear  as  amorphous  oils  and 
the  thymol  compound  crystallizes  most  readily,  contrasting  with 
sodium  in  this.  It  comes  out  easily.  Thus  on  precipitation  by  ether 
the  order  is  this : 
Sodium  derivative  of  carvacrol. 
Potassium  derivative  of  thymol. 
Sodium  derivative  of  thymol. 
Potassium  derivative  of  carvacrob 
ter  Meer,  Ber.,  8  (1875),  p.  622. 
