3-Bromo-2-methylbenzaldehyde

(3-Bromo-2-methylphenyl)methanol (24 g, 119 mmol) was dissolved in dichloromethane (240 mL) and manganese (IV) oxide (103 g, 1.2 mol). After stirring overnight, TLC showed no starting material. The reaction mixture was evaporated with silica gel and loaded on a small silica gel column. After evaporation, the product was eluted with hexane:ethyl acetate (10:1) to give pure aldehyde 3-bromo-2-methylbenzaldehyde (18.6 g).