反应详情

A solution of 14.2 g of 3-difluoromethoxy-2-(o-tolyl)-acrylic acid methyl ester and 0.15 g of dibenzoyl peroxide in 85 ml of carbon tetrachloride is heated to reflux. With radiation from a lamp, 10.44 g of N-bromosuccinimide are then added in several small portions and the reaction mixture is left to react for 1.5 hours. After cooling to room temperature, the reaction mixture is filtered and concentrated by evaporation in vacuo. The pale red crude product is purified by chromatography on silica gel with hexane/ethyl acetate and crystallised from hexane. Pure 2-(2-bromomethylphenyl)-3-difluoromethoxy-acrylic acid methyl ester is obtained; m.p. 63°-67° C.

1. waitthe reaction mixture is left
2. customto react for 1.5 hours
3. filtrationthe reaction mixture is filtered
4. concentrationconcentrated by evaporation in vacuo
5. customThe pale red crude product is purified by chromatography on silica gel with hexane/ethyl acetate
6. customcrystallised from hexane