Water → L-Phenylalanine, methyl ester

Participants

Reaction Steps

To a suspension of N-[[1-[2-(acetylamino)ethyl]cyclopentyl]thioxomethyl]-4-nitro-L-phenylalanine methyl ester (740 mg, 1.75 mmol), zinc dust (1.14 g, 17.5 mmol) and ammonium chloride (1.41 g, 26.3 mmol) in methanol (20 mL) was added H2O (10 mL) slowly over 5 min. After stirring for 20 min, the reaction mixture was diluted with ethyl acetate (80 mL) and sat. ammonium chloride solution (25 mL). The separated aqueous layer was back-extracted with ethyl acetate (3×25 mL) and the organic layers were combined, dried over Na2SO4, filtered and concentrated in vacuo. The residual oil was dried under high vacuum for 2 h to give the crude amine (750 mg) which was by flash silica gel column chromatography (dichloromethane-acetone 2:1) to furnish 4-amino-N-[[1-[2-acetylamino)ethyl]cyclopentyl]thioxomethyl]-L-phenylalanine methyl ester (650 mg, 95%). HR MS: Obs. mass, 392.2016. Calcd. mass, 392.2008 (M+H).

Provenance & Evidence