Patent ID: 7544840
Filing Date: 2009-06-09
Classification: C07B,C07C

Abstract:
1. A method of production of (−)-(S)-3-[1-(dimethylamino)ethyl]phenyl-N-ethyl-N-methylcarbamate, of formula II or of its hydrogentartrate of formula I comprising, reductively aminating methoxyacetophenone of formula VI to form the compound of formula V which is thereafter O-dealkylated to the racemic amine of formula IV which is further resolved by reacting with (S)-(+)-camphor-10-sulfonic acid, whereafter the desired respective diastereoisomer is crystallized and finally converted into the compound of formula III which, in turn, is reacted, optionally in the form of its alkali salt, with a compound of formula VII wherein X is a leaving group to produce (−)-(S)-3-[1-(dimethylamino)ethyl]phenyl-N -ethyl-N-methylcarbamide.