Described is a process for the preparation of compounds of formula (1a) which comprises reacting an isomeric mixture consisting of from 75 to 95 % of compound of formula (2a) and from 5 to 25 % of a compound of formula (2b) with methylamine, in a suitable solvent, to form a sertraline-imine isomeric mixture consisting of from 75 to 95 % of formula (1a) and from 5 to 25 % of formula (1b)(A1), or reacting an isomeric mixture consisting of from 75 to 95 % of a compound of formula (2a) and from 5 to 25 % of a compound of formula (2b) with methylamine, in a suitable solvent, using suitable methods of isolation to form an enriched sertraline-imine isomeric mixture, consisting of > 99 % of a compound of formula (1a) and < 1 % of a compound of formula (1b)(A2); and then subjecting the sertraline-imine isomeric mixture obtained according to reaction route (A1) or (A2), in a suitable solvent, to recrystallisation (B), in accordance with scheme (I) wherein in formula (1a), R1, R2 and R3 are each independently of the others hydrogen, halogen, trifluoromethyl or C1-C4alkoxy and formulae (1b), (2a) and (2b) are as defined in the description.
本发明涉及一种制备式(1a)化合物的方法,包括在适当溶剂中将由75%至95%的式(2a)化合物和由5%至25%的式(2b)化合物组成的同分异构体混合物与
甲基胺反应,以形成由75%至95%的式(1a)和由5%至25%的式(1b)组成的
舍曲林亚胺同分异构体混合物(A1);或者在适当溶剂中,使用适当的隔离方法,将由75%至95%的式(2a)化合物和由5%至25%的式(2b)化合物组成的同分异构体混合物与
甲基胺反应,形成富集的
舍曲林亚胺同分异构体混合物,其中>99%为式(1a),<1%为式(1b)(A2);然后将根据反应路线(A1)或(A2)获得的
舍曲林亚胺同分异构体混合物,在适当溶剂中进行重结晶(B),符合方案(I)中式(1a)中的R1、R2和R3各自独立地为
氢、卤素、三
氟甲基或C1-C4烷
氧基,式(1b)、(2a)和(2b)如描述中所定义。