Process for the manufacture of citalopram hydrobromide from 5-bromophthalide

摘要

A process for the preparation of 1-(4'-fluorophenyl)-1-(3-dimethylamino-propyl)-5-phthalanecarbonitrile of formula (I), or a pharmaceutically acceptable salt thereof,comprising performing two successive Grignard reactions on 5-bromophthalide, wherein the 5-bromophthalide is reacted with the first Grignard reagent in the presence of a Lewis acid, so reducing by-product formation and improving yields.