Patent ID: 6649765
Filing Date: 2003-11-18
Classification: C07D

Abstract:
A process for the preparation of 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine hydrochloride (Donepezil HCl) of the formula I comprising hydrogenating 5,6-Dimethoxy-2-(pyridin-4-yl)methylene inda-1-one with a noble metal oxide catalyst in an organic solvent at 20-50Â° C. and 10-45 psi gauge pressure to form 4-[(5,6-dimethoxy-1-indanon)-2-yl]methyl piperidine of the formula II which is alkylated with an alkylating agent in an organic solvent at 20-80Â° C.