336 
Morphine. 
Am.  Jour.  Pharcn. 
JiiLe,  1884. 
codeine  methiodide,  a  colorless  strongly  alkaline  solution  is  obtained, 
which  gradually  becomes  colored,  and  deposits  methocode'ine.  The 
reaction  is  quickened  by  using  an  excess  of  the  alkali  and  heating  to 
boiling.  The  action  of  the  alkalis  is  therefore  to  liberate  the  hydroxide 
from  which  the  elements  of  water  are  subsequently  eliminated, 
C18H21N03,OH3(OH)  =  C19H23N03  +  H20. 
For  the  preparation  on  a  large  scale,  it  is  best  to  boil  the  methiodide 
with  rather  more  than  the  molecular  weight  of  potassium  hydroxide, 
extract  the  hot  solution  with  benzene,  and  shake  out  the  base  with 
acetic  acid.  The  acetic  solution  is  then  saturated  with  sodium  chloride, 
and  the  precipitated  chloride  recrystallized  from  a  small  quantity  of 
water.  A  concentrated  aqueous  solution  of  the  chloride  is  then  decom- 
posed with  sodium  hydroxide,  and  the  base  at  once  extracted  with  ether. 
In  a  few  minutes  the  ethereal  solution  deposits  long  colorless  prisms 
of  methocodeine.  Freshly  precipitated,  this  substance  dissolves  freely 
in  ether,  but  when  crystallized  only  sparingly.  It  crystallizes  from 
boiling  alcohol  in  prisms,  from  boiling  water  in  needles,  in  the  latter 
case  with  1  mol.  H20.  It  melts  at  118'5°,  and  dissolved  in  97  per 
cent,  alcohol  gives  [a]D  =  —  208*6°  when  p  =  4  and  t=lo°.  In 
moderately  concentrated  sulphuric  acid,  the  base  and  its  salts  dissolve 
to  a  colorless  solution,  which  gradually  becomes  of  a  purplish- violet 
tint,  and  turns  olive-green  when  heated.  The  base  gives  a  blue  color 
when  heated  with  concentrated  sulphuric  acid  The  hydrochloride 
crystallizes  with  2H20  in  needles  soluble  in  10*8  parts  of  water  at  18°. 
The  platinochloride  is  of  a  dark  green  color. 
Methocodeine  dissolves  in  acetic  anhydride  at  85°,  and  yields  acetyl- 
meihocodeine.  It  melts  at  66°,  and  gives  a  blue  coloration  with  con- 
centrated sulphuric  acid.  It  is  soluble  in  alcohol,  sparingly  so  in 
water.  The  salts  crystallize  easily ;  the  hydrochloride  with  JH20,  the 
platinochloride  with  4H20,  the  nitrate  with  3H20,  and  the  sulphate 
with  8H20. 
With  methyl  iodide  methocodeine  forms  a-metho codeine  methiodide, 
crystallizing  in  prisms  with  JH20  and  soluble  in  water.  The  a-metho- 
chloride  is  obtained  from  the  methiodide  by  the  action  of  silver  chloride, 
but  could  not  be  obtained  in  a  crystalline  form.  It  gives  a  blue  color 
with  concentrated  sulphuric  acid.  The  a-platino chloride  is  a  yellow 
nocculent  precipitate.  «-Codei"ne  methochloride  dissolves  in  acetic 
anhydride  forming  a-acetylcode'ine  methochloride,  which  crystallizes 
