A PROCESS FOR THE PREPARATION OF ESCITALOPRAM

摘要

The present invention relates to an improved process for the preparation of escitalopram of the formula-(I) which consists of a sequential double Grignard reaction on 5-iodophthalide to get the dihydroxy compound of formula-(XVI), its resolution using a chiral acid, cyclization of resolved compound of the formula-(XVII), and cyanation of compound of the formula-(XVIII) using DMF and copper (I) cyanide. The present process utilizes the facile displacement of iodo group with cyano group in the final step of escitalopram. Escitalopram is a widely used anti-depressant.