Electrochemical bromination and oxidation of alkyl aromatic compounds by two-phase electrolysis

摘要: A simple, regioselective, environmentally clean and economical method for the preparation of side chain/ ring brominated aromatic compounds is reported in 70–98% yield by an electrochemical using two phase electrolysis technique. Electrochemical reactions were carried out aqueous 25–50 wt% sodium bromide containing catalytic amount (5 wt%) hydrobromic acid as chloroform alkyl organic phase, at a temperature 0–30 °C undivided cell. The same two-phase electrolytic system can be used oxidation benzylic alcohols to corresponding benzaldehydes 80–94% without over carboxylic acids. advantage this very mild procedure room reaction with Excellent conversions are observed. After completion alcohol electrolyte reused number times, demonstrating “spent reagent” free electro attractive one. In case chain/ring bromination compounds, after making up concentration 47 HBr solution. some cases homogeneous applied, where did not work. Styrene epoxidation α-bromination ketones underwent any catalyst. was performed CH3CN-water (3: 2) equimolar NaBr get 68% styrene epoxide. Use ionic liquid 1-butyl 3-methyl imidazolium (Bmim) Br, instead improved current efficiency epoxide 86%.