(2R,4S)-1-tert-butyl 2-methyl-4-azido pyrrolidine-1,2-dicarboxylate (150 mg, 0.390 mmol) was used as a raw material, which was added to methanol (15 mL) together with Pd/C (150 mg, 0.390 mmol). The reaction system was replaced with hydrogen twice, followed by stirring the reaction for 15 h at room temperature. Upon completion of the reaction, the reaction mixture was concentrated to afford methyl (2R,4S)-1-Boc-4-amino-2-pyrrolidinecarboxylate as a gray oil (643 mg, 89% yield). The product was characterized by 1H NMR (600 MHz, CD3OD): δ 4.38-4.41 (m, 1H), 3.74-3.75 (m, 3H), 3.64-3.69 (m, 1H), 3.58-3.61 (m, 1H), 3.16-3.21 (m, 1H), 2.08-2.13 (m, 2H), 1.42- 1.48 (m, 9H); MS-ESI: m/z 145.20 [M+H-100]+.
