反应详情

温度

-20 °C

To a solution of (2S)-2-[(tert-butoxycarbonyl)amino]butanoic acid (1.01 g, 4.99 mmol) in DMF (5 mL) at −20° C. was added NMM (1.10 mL, 9.99 mmol) and isobutyl chloroformate (1.30 mL, 9.99 mmol). The reaction was stirred for 10 min at −20° C. The precipitate was removed by filtration. 26% NH4OH (aq) solution (0.39 mL, 9.99 mmol) was added and the reaction was stirred at −20° C. for 3 h. The volume was reduced under vacuum and hexane was added. A white precipitate was formed after a few minutes. The precipitate was collected in a filter and washed with additional hexane. The precipitate was recrystallised from EtOAc and hexane to give the title compound (0.811 g, 80%) as white solid.

1. customThe precipitate was removed by filtration
2. stirringthe reaction was stirred at −20° C. for 3 h
3. additionwas added
4. customA white precipitate was formed after a few minutes
5. customThe precipitate was collected in
6. filtrationa filter
7. washwashed with additional hexane
8. customThe precipitate was recrystallised from EtOAc and hexane