Patent ID: 9688658
Date: 2017-06-27
CPC Classifications: A61P,C07B,C07D

Claim:
1. Process for the preparation of Esomeprazole having high optical purity of formula (I): comprising the following steps: A. providing a solution containing an enantiomerically enriched mixture of the optical isomers of formula (I) and (II): wherein the ratio between the optical isomers (I) and (II) is from 60:40 to 99:1, and wherein the solvent of said solution is dichloromethane; B. promoting the crystallization of the compound of formula (III): said compound being substantially in racemic form; C. adding an ethereal solvent to the suspension prepared in the step B; D. filtering the suspension prepared in the step C to remove the compound of formula (III); E. isolating Esomeprazole having increased optical purity or salts thereof from the filtrated solution of the step D.