1. tert-Butyl 1-benzyl-5-oxopyrrolidin-3-ylcarbamate (480 mg, 1.65 mmol) was dissolved in tetrahydrofuran (6 mL).
2. 4 N hydrogen chloride/dioxane solution (6.0 mL, 24 mmol) was added to the above solution.
3. The reaction mixture was stirred at room temperature overnight. 4.
4. Upon completion of the reaction, diethyl ether (35 mL) was added to the reaction solution and stirring was continued for 30 minutes at room temperature.
5. The precipitate was collected by filtration and washed with ether. 6.
6. 1-Benzyl-4-aminopyrrolidin-2-one hydrochloride (380 mg, 99% yield) was obtained after drying. 7. The product was dried over 1H-NHPA.
7. The product was characterized by 1H-NMR (DMSO-d6): δ 2.23 (1H, dd, J = 4.0, 17.2 Hz), 2.76 (1H, dd, J = 8.6, 17.2 Hz), 3.22 (1H, dd, J = 4.0, 10.8 Hz), 3.53 (1H, dd, J = 7.7, 10.8 Hz), 3.89 ( 1H, bs), 4.30 (1H, d, J = 15.0 Hz), 4.45 (1H, d, J = 15.0 Hz), 7.30 (5H, m), 8.32 (2H, bs).
