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. After addition, methylene chloride (50 mL) and cupric bromide (30.0 g, 0.244 mol) were added slowly. The reaction mixture was then warmed to ambient temperature, stirred for one hour, filtered through a bed of celite, and extracted with methylene chloride (2×100 mL). The combined organic phases were dried 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. additionwere added slowly
2. filtrationfiltered through a bed of celite
3. extractionextracted with methylene chloride (2×100 mL)
4. customThe combined organic phases were dried
5. concentrationconcentrated