BigPatents India

A process for preparing vanlafaxine hydrochloride and also a process for preparing 1-[2-amino-1-(4-methoxy phenyl)ethyl]cyclohexanol hydrochloride, an intermediate of venlafaxine hydrochloride are disclosed. p-Methoxy phenyl acetonitrile is condensed with cyclohexanone in the presence of a base selected from alkali metal alkoxides and solvent selected from C4 alcohol at – 10 to – 5Û&WRREDLQ-[cyano-1-(p-methoxy phenyl)methyl] cyclohexanol which is directly converted it into the 1-[2-amino-1-(4-methoxy phenyl)ethyl]cyclohexanol without being isolated. The molar ratio of base to p-methoxy phenyl acetonitrile of cyclohexanone used is 0.1 to 0.4:1. The 1-[2-amino-1-(4-methoxy phenyl)ethyl]cyclohexanol is converted its hydrochloride salt and subsequently formylated to venlafaxine base. The venlafaxine base is further converted into its salt namely venlafaxine hydrochloride. Both venlafaxine hydrochloride and 1-[2-amino-1-(4-methoxy phenyl)ethyl]cyclohexanol hydrochloride are obtained in high yield with high purity. Drawing: NIL Total Pages: 25