A solution of 4-bromo-3-methylbenzaldehyde (4 g, 20 mmol) in dry tetrahydrofuran (40 mL) was cooled to 0°C under nitrogen atmosphere, and then methyl magnesium bromide (20 mL, 1N in tetrahydrofuran) was added dropwise. The ice bath was removed, and the mixture was stirred for 2 hours. Ammonium chloride aqueous (40 mL) was added and the mixture was extracted with dichloromethane (20 mL * 3). The organic phase was dried by sodium sulphate, filtered and concentrated to give a residue. The residue was purified by column chromatography (silica gel, petroleum ether/ethyl acetate = 5:1) to give 1-(4-bromo-3-methylphenyl)ethanol. Colorless oil, yield 4.0 g, 93%. Pyridinium chlorochromate (48 g, 223 mmol) was added to a solution of 1-(4-bromo-3-methylphenyl)ethanol (31.9 g, 148 mmol) in dichloromethane (800 mL). The mixture was stirred at room temperature for 2 hours. The mixture was concentrated to give a residue. The residue was purified by column chromatography (silica gel, petroleum ether/ethyl acetate = 25:1) to give 4'-Bromo-3'-methylacetophenone. Yield 27.3 g, 87%.
Figure Synthesis of 4'-Bromo-3'-methylacetophenone
