104 
Preparation  of  Formio  Ether. 
f  Am.  Jour.  Pharm* 
\      Mar.,  1881. 
THE  PREPAKATIOIN^  OF  FORMIC  ETHER. 
By  Henry  Trimble,  Ph.G. 
Having  occasion  to  prepare  considerable  quantities  of  this  ether, 
and  finding  the  process  in  which  sodium  formate  is  employed  a  long 
and  tedious  one,  it  occurred  to  me  that  it  might  be  made  by  adding 
alcohol  to  the  acid  during  its  formation  from  oxalic  acid  and  glycerin. 
I  have  since  found  the  fact  mentioned  in  an  English  text-book  on 
chemistry,  but  as  no  formula  is  given  I  oifer  the  following,  with  the 
hope  of  benefitting  those  who  have  never  met  with  the  statement. 
Ten  parts  each  of  oxalic  acid  and  glycerin  with  one  part  of  water 
are  heated  in  a  flask,  connected  with  a  condenser,  for  about  12  hours, 
at  a  temperature  between  100°  and  110°C.  When  effervescence  has 
ceased  a  small  quantity  of  liquid  will  be  found  in  the  receiver,  but  as 
that  is  largely  water  it  may  be  rejected.  To  the  mixture  in  the  flask, 
consisting  of  glycerin  and  formic  acid,  is  added  four  parts  of  alcohol, 
and  the  whole  kept  at  a  temperature  not  exceeding  50°C.  for  several 
hours.  It  is  then  submitted  to  distillation,  continued  until  the  ther- 
mometer indicates  120^0.  The  distillate  is  found  to  consist  of  two 
layers.  The  upper  ethereal  one  is  separated,  washed  with  water  con- 
taining a  little  sodium  hydrate,  and  distilled. 
The  yield  is  about  four  parts,  specific  gravity  '910  at  15'5°C.,  while 
theoretically  it  should  be  eight  parts,  a  loss  which  may  be  accounted 
for.  By  adding  five  parts  of  water  to  the  contents  of  the  flask  and 
distilling,  a  moderate  quantity  of  formic  acid  will  be  obtained.  It  was 
thought  that  if  alcohol  were  added  instead  of  water  an  additional 
amount  of  the  ether  might  be  obtained;  but  this  is  not  the  case, 
because  the  acid  is  so  diluted  by  the  glycerin  that  it  will  not  combine 
with  the  alcohol.  There  is  always  a  great  loss  when  the  ether  is  man- 
ufactured from  sodium  formate,  therefore  this  process  is  ofl^ered  as  not 
only  being  cheaper  but  also  as  furnishing  a  purer  product  with  less 
trouble  and  in  less  time.  It  may  not  be  out  of  place  to  mention  that 
amyl  formate  may  be  prepared  in  the  same  way,  therefore,  in  all  prob- 
abilitv,  the  formates  of  the  other  radicals. 
PMlaclelpUa,  Feb.  14,  1881. 
