反应详情

To a stirred solution of 2-amino-5,5,5-trifluoropentanoic acid hydrochloride (400 mg, 1.503 mmol) in THF (8 mL) and water (8 mL) was added K2CO3 (831 mg, 6.01 mmol) at rt and the solution was stirred for 10 min. To this mixture was added BOC2O (656 mg, 3.01 mmol). The reaction mixture was stirred for 8 h at rt. The reaction mixture was concentrated under reduced pressure. The aq. layer was washed with ethyl acetate (3×5 mL). The aqueous layer was acidified with saturated citric acid solution (5 mL) and then extracted with ethyl acetate (3×8 mL). The combined organic layers were washed with water (3×5 mL) followed by brine (10 mL), dried over sodium sulfate and concentrated under reduced pressure to afford 2-((tert-butoxycarbonyl)amino)-5,5,5-trifluoropentanoic acid (500 mg, 1.84 mmol) quantitatively as a colorless oil. The crude material was taken as such to the next step without further purification. 1H NMR (400 MHz, CDCl3) δ 5.04 (s, 1H), 4.38 (s, 1H), 2.15-2.28 (m, 2H), 1.91-1.95 (m, 2H), 1.46 (s, 9H).

1. stirringThe reaction mixture was stirred for 8 h at rt
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. washThe aq. layer was washed with ethyl acetate (3×5 mL)
4. extractionextracted with ethyl acetate (3×8 mL)
5. washThe combined organic layers were washed with water (3×5 mL)
6. dry with materialdried over sodium sulfate
7. concentrationconcentrated under reduced pressure