反应详情

温度

-20 °C

A 1 M solution of BBr3 (9 ml, 9 mmol) in CH2Cl2 was added to a well-stirred solution of 5-benzyloxy-3,4′-difluorostilbene (0.97 g, 3 mmol) in dry CH2Cl2 (120 ml) at −78° C. The mixture was warmed to −20° C. and stirred for 10 minutes. Then MeOH was added at −78° C. The mixture was washed with saturated NaHCO3, and water. Flash chromatography gave the 3,4′-difluoro-5-hydroxystilbene (0.60 g, 86%) as white solid. Data are: 1H NMR (CDCl3, 300 MHz) δ 7.46 (m, 2H), 7.08-6.73 (m, 6H), 6.48 (dt, 1H), 4.85 (s, 1H); 13C NMR (CDCl3, 75 MHz) δ 165.05 (d), 161.78 (d), 157.06 (d), 140.43 (d), 133.06 (d), 129.40 (s), 128.45 (d), 127.25 (t), 115.95 (d), 109.42 (d), 105.91 (d), 102.60 (d); 19F NMR (CDCl3, 282 MHz) δ-31703.17 (t), −32099.92 (t); HRMS (EI+) found 232.0714 M+, calcd 232.0700 for C14H10F2O.

1. washThe mixture was washed with saturated NaHCO3, and water