Effect of solvent on stereoselectivity in Pd/C (type 39K)-Catalyzed hydrogenation of methyl 3-oxo-4-aza-5-androstene-17-carboxylateg, a key intermediate for Finasteride and Dutasteride

摘要

Solvent effects were studied in the stereoselective hydrogenation of methyl 3-oxo-4-aza-5-androstene-17-carboxylate (7) using reactivated Pd/C (type 39K) as a catalyst to furnish methyl 3-oxo4-aza-5-a--androstene-17-carboxylate (2a), a common key intermediate for finasteride (1a) and dutasteride (1b), and reaction conditions were optimized to provide the required isomer with better selectivity.