Tert-butyl 4-aminomethyl-4-(2,2,2-trifluoroacetamido)piperidine-1-carboxylate (400 mg, 1.2 mmol) was used as a raw material, which was dissolved in a mixed solution of MeOH/H2O (5/2, 5 mL) in 10% K2CO3 and the reaction was carried out at reflux overnight. Upon completion of the reaction, the reaction mixture was cooled to room temperature, followed by solvent evaporation. The residue was dissolved in ethyl acetate and washed sequentially with water and saturated saline. The organic layer was dried over anhydrous MgSO4, filtered and the solvent evaporated to afford 250 mg (91% yield) of the target product tert-butyl 4-amino-4-(aminomethyl)piperidine-1-carboxylate, which could be used in the subsequent reaction without further purification.1H NMR (400 MHz, CD3OD) δ 3.63-3.57 (m, 2H), 3.36 (s, 2H), 3.36-3.30 (s, 2H), 3.36-3.30 (s, 2H). 3.36-3.30 (m, 2H), 1.62-1.40 (m, 4H), 1.45 (s, 9H).
