2-Bromo-2'-methoxyacetophenone

579-74-8

31949-21-0

The general procedure for the synthesis of o-methoxy-2-bromoacetophenone from 2'-methoxyacetophenone was as follows: copper(II) bromide (2.97 g, 6.66 mmol) was added to a two-necked round-bottomed flask equipped with a reflux condenser. Ethyl acetate (10.0 mL) was added to the flask and the mixture was stirred at 70 °C for 5 min under nitrogen protection. A solution of chloroform (10.0 mL) of 1-(2-methoxyphenyl)ethanone (0.50 g, 3.33 mmol) was slowly added, followed by refluxing the reaction mixture for 8 hours. After completion of the reaction, it was cooled to room temperature, filtered through a diatomaceous earth pad and the filter cake was washed with ethyl acetate (20 mL). The filtrate was concentrated under reduced pressure and the crude product obtained was purified by column chromatography (eluent ratio ethyl acetate:hexane = 1:4) to afford the pure o-methoxy-2-bromoacetophenone (0.73 g, 96% yield) as a brown liquid. Thin layer chromatography Rf value was 0.43 (unfolding agent ratio ethyl acetate:hexane = 1:4); 1H NMR (300 MHz, CDCl3) δ: 7.81 (1H, dd, J = 7.8, 1.8 Hz), 7.52 (1H, td, J = 7.8, 1.8 Hz), 7.05-6.96 (2H, m), 4.61 (2H, s). 3.94 (3H, s); 13C NMR (75 MHz, CDCl3) δ: 192.3, 158.8, 134.9, 131.6, 124.9, 121.2, 111.7, 56.0, 38.0.