反应详情

To a solution of 2(S)-tert-butoxycarbonylamino-3-(4-fluorophenyl)propionic acid (1.5 g, 5.29 mmol) in ethyl acetate (100 mL) under an argon atmosphere was added triphosgene (628 mg, 2.12 mmol). To the solution was added triethylamine (0.8 mL 5.76 mmol,) over 1 min, and the reaction stirred for 72 h at rt. The reaction mixture was filtered, and the filtrate concentrated in vacuo to yield an oily residue. The crude material was crystallised from cold dichloromethane and petroleum ether to give the title compound. δH (CD3OD): 7.20 (2H, m), 7.10 (2H, m), 5.86 (1H, s, (NH)), 4.58 (1H, s), 3.33–3.23 (2H, m), 3.11–3.00 (1H, m).

1. filtrationThe reaction mixture was filtered
2. concentrationthe filtrate concentrated in vacuo
3. customto yield an oily residue
4. customThe crude material was crystallised from cold dichloromethane and petroleum ether