反应详情

To a solution of potassium bromide (40 g) in H2O (250 mL) was added bromine (6.8 mL). To the dark red solution was added aldehyde 10 (20.2 g). The turbid orange solution was stirred overnight, filtered, rinsed with ethyl acetate, recrystallized from ethyl acetate/hexane to afford yellow crystals (22.4 g, 79%): m.p. 121.6-123.4° C., lit18 m.p. 119-120° C.; EIMS m/z 274 (M+, 81Br), 272 (M+, 79Br), 232, 230, 186, 184, 43; 1H NMR δ 10.26 (1H, s, CHO), 7.51 (1H, d, J=9.0 Hz, H4), 7.05 (1H, d, J=9.0 Hz H2, H4), 3.85 (3H, s, OCH3), 2.38 (3H, s, COCH3); 13C—NMR (75.5 MHZ) δ 190.38, 168.71, 151.78, 140.37, 131.41, 126.49, 117.69, 116.35, 56.40, 20.44. Anal. Calcd. For C10H9O4Br: C, 43.98; H, 3.32. Found: C, 44.46; H, 3.55.

1. filtrationfiltered
2. washrinsed with ethyl acetate
3. customrecrystallized from ethyl acetate/hexane