(R)-5-(3,4-difluorophenyl)-3,4-dihydro-2H-pyrrole-2-carboxylic acid ethyl ester → (2R,5S)-5-(3,4-difluorophenyl)pyrrolidine-2-carboxylic acid ethyl ester

Participants

Reaction Steps

10% palladium on carbon (1.2 g, 50% water content) was added to an ethanol (160 mL) solution of (R)-5-(3,4 difluorophenyl)-3,4-dihydro-2H-pyrrole-2-carboxylic acid ethyl ester (12.2 g), and under a hydrogen atmosphere, stirring was continued for 16 hours at room temperature. The catalyst was filtered on celite, and the filtrate was concentrated, and ethanol (160 mL) and 10% palladium on carbon (1.2 g, 50% water content) was again added to the residue, and under a hydrogen atmosphere, stirring was continued for 15 hours at room temperature. The catalyst was filtered on celite, and the filtrate was concentrated, and the residue was purified by silica gel column chromatography (heptane/ethyl acetate), and the title compound (8.86 g) was obtained. The physical property values are as follows.

Provenance & Evidence