To a reaction flask was added 4-bromopiperidine hydrobromide (5.0 g, 20.4 mmol) and dichloromethane (80 mL) followed by saturated sodium bicarbonate solution (160 mL) and benzyl chloroformate (3.7 mL, 24.5 mmol). The reaction mixture was stirred at 23 °C for 22 hours. Upon completion of the reaction, the mixture was transferred to a partition funnel and the product was extracted with dichloromethane. The organic phases were combined, washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated. Purification by silica gel column chromatography (eluent: hexane/ethyl acetate = 8:1) afforded benzyl 4-bromopiperidine-1-carboxylate (3.02 g, 10.1 mmol, 50% yield) as a colorless oil. Mass spectrum (MS): m/e 298.
