1: L-proline With potassium hydroxide in isopropyl alcohol T=40°C; 2: benzyl chloride in dichloromethane; isopropyl alcohol T=0 - 40°C; 6 h; 3: With hydrogenchloride in water; isopropyl alcohol T=20°C; pH=4;

hydrogenchloride

dicyclohexyl-carbodiimide in dichloromethane T=-20°C; 2 h;