| 内容提要: |
L-Aspartic acid β-benzyl ester (2 g, 8.96 mmol) and triphosgene (1.33 g, 4.48 mmol) were taken into 50 mL round flask, followed by 20 mL anhydrous THF added and the suspension was stirred at 50oC for 3 h under nitrogen atmosphere. The reaction mixture was concentrated using rotary evaporator to 5 mL and then precipitated in 100 mL iced hexane. The obtained precipitate was re-dissolved in 1 mL anhydrous THF, followed by crystallization in ice-cold hexane. The monomer BLA-NCA was obtained by vacuum drying (yield: 72%) |