反应详情

A solution of 4-chloro-2-fluoro-5-methoxyaniline (25.0 g, 0.143 mol) in 10% HBr (250 mL) was cooled to 0° C. and a solution of sodium nitrite (15.0 g, 0.218 mol) in water (20 mL) was slowly added. Methylene chloride (50 mL) and curpric bromide (30.0 g, 0.244 mol) were added slowly and then the mixture was warmed to ambient temperature and stirred for 1 hour. The reaction mixture was filtered through a bed of celite and extracted with methylene chloride (2×100 mL) and the combined organic phases were dried (sodium sulfate) and concentrated. Chromatography of the dark oil (5% ethyl acetate in hexanes) gave 1-bromo-4-chloro-2-fluoro-5-methoxybenzene (16.6 g, 0.070 mol): 1H NMR (CDCl3): δ 7.20 (m, 1H) 7.05 (dd, 1H), 4.00 (s, 3H).

1. filtrationThe reaction mixture was filtered through a bed of celite and
2. extractionextracted with methylene chloride (2×100 mL)
3. dry with materialthe combined organic phases were dried (sodium sulfate)
4. concentrationconcentrated