Am.  .Tour.  Pharm. 
Nov,,  1892. 
Lignite  Tar. 
585 
LIGNITE  TAR.1 
By  F.  Heusler. 
A  quantity  of  the  lighter  portions  of  the  distillate  from  lignite 
tar  was  fractionated  after  treatment  with  dilute  acids  and  alkalis. 
On  distillation  at  ordinary  pressures,  decomposition  sets  in  at  about 
1800.  The  oil  is  readily  attacked  in  the  cold  by  potassium  perman- 
ganate in  dilute  sulphuric  acid  solution.  A  quantity  (1.950  cc.)  of  the 
oil  boiling  at  148-1620  was  treated  with  potassium  permanganate 
(167  grams}  in  the  cold  until  the  action  was  over.  On  steam  dis- 
tillation, an  oil  (1,208  grams)  boiling  at  130-1650  was  obtained; 
the  largest  fraction  (328  grams)  of  this  distilled  at  145-150°.  The 
lower  boiling  parts  of  the  crude  tar  oil  are  acted  on  with  explosive 
violence  by  nitric  acid.  After  treatment  with  potassium  permanga- 
nate, however,  nitration  proceeds  quietly  ;  the  greater  portion  of 
the  oil  dissolves  with  evolution  of  gas,  and  on  pouring  the  acid 
solution  into  water,  a  heavy  oil  separates  which  is  partially  soluble 
in  soda.  A  considerable  proportion,  however,  remains  undissolved, 
and  consists  of  nitro-derivatives  of  aromatic  hydrocarbons. 
On  fractional  bromination  in  the  cold  of  the  oil  dissolved  in  ether, 
a  product  is  obtained  which  may  be  separated  by  steam  distillation 
into  a  light  and  a  heavy  oil.  The  lighter  portion  consists  of  bromo- 
derivatives  of  aromatic  hydrocarbons. 
Lignite  tar  oil  is  readily  acted  on  by  concentrated  sulphuric  acid 
with  evolution  of  sulphurous  anhydride.  The  oil  (15  parts),  if 
agitated  first  with  a  mixture  of  water  (1  part)  and  concentrated  sul- 
phuric acid  (2  parts)  and  then  with  a  mixture  (4^  parts)  of  water 
(1  part)  and  concentrated  sulphuric  acid  (3  parts),  yields  an  oil 
which,  on  steam  distillation  and  subsequent  fractionation,  is  found 
to  be  similar  to  that  obtained  by  oxidation  with  permanganate  and 
to  have  a  strongly  aromatic  odor.  The  fraction  of  this  oil,  boiling 
at  80-930  was  found,  by  nitration,  to  contain  about  34  per  cent,  of 
benzene.  The  fraction  boiling  at  100-1100  of  the  oil  obtained  by 
the  treatment  with  permanganate,  described  above,  was  found  by 
nitration  to  contain  about  45  per  cent,  of  toluene.  Derivatives  of 
metaxylene  and  mesitylene  were  also  recognized  among  the  pro- 
ducts of  nitration.    The  fraction  boiling  at  135-1400  of  the  oil 
1  Berichte,  25,  1665-1678  \Jour.  Chem.  Soc,  September,  1892,  p.  1075. 
