83220-73-9

124-63-0

141699-57-2

GENERAL STEPS: To a stirred solution of 1-tert-butoxycarbonyl-3-hydroxypyrrolidine (16 g, 85.4 mmol) and triethylamine (19 mL, 129 mmol) in 130 mL of dichloromethane was added slowly and dropwise to a solution of methanesulfonyl chloride (10 mL, 129 mmol) in 20 mL of dichloromethane at 0 °C. After the dropwise addition was completed, the reaction mixture was continued to be stirred at room temperature for 2.5 hours. Upon completion of the reaction, the reaction was quenched with saturated aqueous sodium bicarbonate and extracted with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure to give tert-butyl 3-methanesulfonyloxypyrrolidine-1-carboxylate (22.7 g, 100% yield) as a yellow solid.