反应详情

To the title compound from Step A (1.70 g, 4.40 mmol) in MeOH (10 mL) was added 4N NaOH (10 mL). After 2 h, CH2Cl2 was added and the mixture acidified with 1N KHSO4 (50 mL) then extracted with CH2Cl2 (2×). The combined organics were dried to give a 0.90 g (57%) of the title compound as a white solid that was used without further purification. MS (ESI): mass calcd. for C16H20ClNO6, 357.1; m/z found, 380.1 [M+Na]+. 1H NMR (400 MHz): 6.92 (dd, J=8.6, 2.3 Hz, 1H), 6.85 (d, J=8.7 Hz, 1H), 6.59 (d, J=2.3 Hz, 1H), 4.92-4.86 (m, 1H), 4.67 (s, 2H), 4.31 (dd, J=9.9, 6.5 Hz, 2H), 4.07 (dd, J=10.0, 4.1 Hz, 2H), 1.45 (s, 9H).

1. extractionthen extracted with CH2Cl2 (2×)
2. customThe combined organics were dried