反应详情

To a solution of the title compound of Step A (270 mg, 1.5 mmol) and 3-hydroxy-azetidine-1-carboxylic acid tert-butyl ester (270 mg, 1.5 mmol) in dry DMF (10 mL) at 0° C. was added NaH (60% in mineral oil, 22 mg, 1.5 mmol). After 18 h, H2O and EtOAc were added and the aqueous layer was extracted with EtOAc. The combined organic extracts were dried and concentrated. The crude residue was purified by RP HPLC to provide the title compound (75 mg, 15%). MS (ESI): mass calcd. for C15H17ClFNO4, 329.1; m/z found, 274.0 [M+H-56]+. 1H NMR (CDCl3): 10.4 (s, 1H), 6.84 (dd, J=10.0, 1.6 Hz, 1H), 6.39 (dd, J=1.4, 1.3 Hz, 1H), 5.00-4.92 (m, 1H), 4.38 (dd, J=9.9, 6.3 Hz, 2H), 4.08 (dd, J=10.7, 4.0 Hz, 2H), 1.46 (s, 9H).

1. extractionthe aqueous layer was extracted with EtOAc
2. customThe combined organic extracts were dried
3. concentrationconcentrated
4. customThe crude residue was purified by RP HPLC