PROCESS FOR PREPARATION OF PAROXETIN INTERMEDIATE

摘要

A trans-piperidinedione of formula (1), where R is a benzyl group and R' is an optionally substituted C1-6-alkyl, aryl-C1-6-alkyl, C1-6-allyl or aryl group, which process comprises the reaction of a cinnamate ester of formula (3), where R'' has independently the same meaning as R', with a malonamide (4) in the presence of a strong base. Compound (2) is used in the presentation of paroxetine. The preparation of paroxetine by the route from compounds (3 and 4) avoids the formation of difficult to remove impurities found in other routes.