122 
Urethancs  of  Thymol  and  Carvacrol.    :  Am.  jour.  Pharm. 
'         -  I  February,  1921. 
It  thus  becomes  apparent  that  the  substance  which  Neuberg  and 
Hirschberg  had  obtained  was  not  the  cc  -naphthyl  urethane  of  car- 
vacrol but  a  decomposition  product  of  oc  -napthyl  isocyanate  or  a 
mixture  which  happened  to  yield  a  result  for  nitrogen  about  what 
they  expected.  The  substituted  urea  obtained  directly  as  a  decom- 
position product  of  the  isocyanate  in  the  air  melts  at  264°  or  a  little 
higher,  the  melting  point  of  their  urethane.  but  contains  8.98  per 
cent,  nitrogen. 
The  carvacrol  compound  isolated  here  is  similar  to  the  thymol 
compound,  perfectly  stable,  colorless  needles  or  felted  needles,  and 
exactly  similar  to  the  phenyl  urethane  as  regards  these  properties 
and  soluble  with  practically  the  same  characteristics.  These  four 
derivatives  are  strictly  analogous  and  belong  to  the  same  type. 
A pplicat'wn  to  Hydrothymoqmnone. — By  analogy  with  phenyl 
isocyanate  cc  -naphthyl  isocyanate  should  for  the  diurethane.  The 
reagents  were  taken  in  that  proportion:  2.26  g.  isocyanate  to  1.21  g. 
phenol,,  and  boiled  under  a  reflux  with  20  cc.  petroleum.  The  crys- 
talline product  never  completely  dissolved  showing  that  some  reac- 
tion took  place  on  mixing  the  reagents.  During  heating  a  mixture 
of  partially  melted  crystals  deposited.  This  behavior  is  similar  to 
that  with  phenyl  isocyanate.  The  crystalline  product  recovered 
weighed  2.288  g.  corresponding  to  a  yield  of  67.8  per  cent,  of  the 
diurethane  based  on  the  isocyanate  taken  or  93.8  per  cent,  of  the 
monourethane  based  on  the  phenol  taken. 
Y\ 'hen  plunged  into  a  bath  at  135"  the  substance  melted  to  a 
turbid  liquid,  which  cleared  finally  at  180°.  After  solution  in  alco- 
hol, a  slightly  soluble  portion  crystallized  out  on  cooling.  This 
melted  at  266-270"  and  corresponds  to  the  urea  obtained  as  a  by- 
product. 
In  other  particlars  this  reaction  product  revealed  itself  to  be  a 
mixture.  Alcohol  separated  a  slight  amount  of  a  crystalline  product 
sufficient  for  an  analysis  and  melting  point.  Its  behavior  toward 
solvents  suggested  a  monoderivative.  It  formed  white  microscopic 
crystals  from  alcohol,  melting  at  147-148°.  with  softening  at  about 
142'.    Analysis  gave  the  following: 
I-  o.T343g.'  gave  5.6  cc  N2  at  24-  and  708  mm. 
Found  Calculated  for  C21H21N03 
Nitrogen    T.        4.50  p.  c.  4.18  p.  c. 
