Under nitrogen atmosphere, benzyl 4-(hydroxymethyl)piperidine-1-carboxylate (10 g, 40.11 mmol) was added to a 500 mL three-necked round-bottomed flask, dissolved in dichloromethane (100 mL), and the mixture was cooled to 0 °C. Subsequently, a solution of triphenylphosphine (13.7 g, 52.14 mmol) in dichloromethane (50 mL) was slowly added to the reaction mixture and kept stirring at 0°C for 20 minutes. Next, a dichloromethane (50 mL) solution of carbon tetrabromide (16 g, 48.13 mmol) was added and the reaction mixture was brought to room temperature and stirred for 3 hours. Upon completion of the reaction, the reaction mixture was diluted with dichloromethane and washed with deionized water. The organic layer was separated, dried with anhydrous sodium sulfate and concentrated under reduced pressure. Finally, purification by column chromatography afforded benzyl 4-(bromomethyl)piperidine-1-carboxylate (10 g).
