DEDOUBLEMENT D'UN ACIDE ORGANIQUE, INTERMEDIAIRE DE SYNTHESE

摘要

1346658 Resolution of 2-(2#-benzyloxymethyl - 3α- hydroxy - 4 - cyclopenten - 1α- yl) acetic acid PFIZER Inc 15 July 1971 [2 March 1971] 33368/71 Heading C2C The invention comprises a process for resolving 2 - (2# - benzyloxymethyl - 3α- hydroxy - 4- cyclopenten-1α-yl)acetic acid by fractional crystallization of its ( + )-amphetamine salt from a mixture of isopropyl ether and one of chloroform, methylene chloride, or acetonitrile and reconverting said amphetamine salt to the optically active free acid. In said mixed solvent the preferred ratio of isopropyl ether to the other solvent may be from 1 : 5 to 5 : 1. It is preferred to dissolve the racemic acid in chloroform, methylene chloride, or acetonitrile, e.g. with heating and to add (+)-amphetamine to the solution followed by isopropyl ether. The solution may be seeded while still warm, with a crystal of resolved salt.