Benzyl chloroformate → 3-Benzyloxycarbonylamino-3-methyl-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a mixture of 3-amino-3-methyl-pyrrolidine-1-carboxylic acid tert-butyl ester (5.0 g, 25 mmol) and potassium carbonate (3.8 g, 27 mmol) in THF (25 mL) and water (25 mL) was added benzyl carbonochloridate (4.6 g, 27 mmol) at 0° C. and the reaction mixture was stirred at ambient temperature overnight. The reaction mixture was diluted with water (25 mL) and extracted with EtOAc (3×15 mL). The combined organic phase was washed with brine (25 mL), dried over sodium sulfate and filtered. The filtrate was concentrated in vacuo and the residue was purified by column chromatography on silica gel (eluting with 4% EtOAc in petroleum) to give 3-benzyloxycarbonylamino-3-methyl-pyrrolidine-1-carboxylic acid tert-butyl ester (5.5 g, 70%). 1H NMR (400 MHz, CDCl3) δ 7.35 (s, 5H), 5.14-5.02 (m, 2H), 4.88-4.79 (m, 1H), 3.63-3.23 (m, 4H), 2.25 (m, 1H), 1.88-1.77 (m, 1H), 1.45 (s, 12H).

Provenance & Evidence