Synthesis of 4-(Azidomethyl)piperidine HCl

In an oven-dried round bottom flask was dissolved tert-butyl 4-(azidomethyl)piperidine-1-carboxylate (15.2 g, 63.3 mmol, 1.00 equiv.) in methanol (210 mL, C ∼ 0.2 M). The solution was cooled to 0°C and acetyl chloride (54.2 mL, 760 mmol, 12.0 equiv.) was added dropwise through a syringe over 30 minutes. The reaction was allowed to warm to room temperature and stirred for 18 h until the complete consumption of the starting material (monitored by TLC). Excess of acetyl chloride and methanol were removed under reduced pressure and the residue was poured into diethyl ether and stirred at room temperature for 1 h. The resulting precipitate was filtered off, washed with cold diethyl ether (3 x 100 mL) and dried under reduced pressure to provide 4-(azidomethyl)piperidine hydrochloride as a white cristalline solid (11.0 g, 98% yield).