反应详情

A solution of [2-(4-bromo-2-fluoro-benzylcarbamoyl)-5-chloro-phenoxy]-acetic acid ethyl ester (1.23 g, 2.8 mmol) in ethanol (16 mL, 0.18 M) was cooled to 0° C. and treated with aq NaOH (1.25 M, 7.0 mL, 8.7 mmol). After stirring for 2.5 h, the solution was warmed to room temperature and stirred an additional 24 h. Next, the solution was acidified to pH 1–2 with 2 N HCl, diluted with ethyl acetate and washed with saturated aq NaCl. The organic layer was dried over Na2SO4, filtered and concentrated to give (2-(4-bromo-2-fluoro-benzylcarbamoyl)-5-methoxy-phenoxy]-acetic acid as a white solid (1.03 g, 89%): mp 203–204° C.; Rf 0.10 (10% methanol in dichloromethane); 1H NMR (DMSO-d6, 300 MHz) δ 9.02 (br t, J=5.9 Hz, 1 H), 7.84, (d, J=8.2 Hz. 1 H), 7.50, (br d, J=8.7 Hz, 1 H), 7.48–7.29 (m, 2 H), 6.69–6.80 (m, 2 H), 4.87 (s, 2 H), 4.49 (d, J=5.8 Hz, 2 H), 3.79 (s, 3 H). ESI-LC/MS m/z calcd for C17H15BrFNO5: 411.0; found 412.0 (M+1)−. Anal. calcd for C17H15BrFNO5: C, 49.53; H, 3.67; N, 3.40. Found C, 49.48; H, 3.68; N, 3.39.

1. stirringstirred an additional 24 h
2. washwashed with saturated aq NaCl
3. dry with materialThe organic layer was dried over Na2SO4
4. filtrationfiltered
5. concentrationconcentrated