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.
本发明涉及一种改进的制备埃司他普兰的方法,其包括在5-
碘邻苯二甲酸酯上进行顺序双
格氏试剂反应,得到
化学式-(XVI)的二羟基化合物,使用手性酸对该化合物进行分离,环化分离后的化合物得到
化学式-(XVII),并使用
DMF和
铜(I)
氰化物对
化学式-(XVIII)的化合物进行
氰化。本方法利用在埃司他普兰的最后一步中
碘原子与
氰基易于替换的特性。埃司他普兰是一种广泛使用的抗抑郁药物。