2-Bromo-5-chloro-1,3-difluorobenzene is synthesised using 4-bromo-3,5-difluoroaniline as a raw material by chemical reaction. The specific synthesis steps are as follows: 4-bromo-3,5-difluoroaniline (25.0g, 117mmol), copper chloride (I) (23.1g, 230mmol) and copper chloride (II) (47.0g, 350mmol) in acetonitrile (150 mL) mixed solution in, it was added dropwise acetonitrile (50 mL) solution of isoamyl nitrite (49.0mL, 350mmol) at room temperature. After stirring for 4 hours at room temperature the mixture solution, poured into 2N hydrochloric acid (300mL), diethyl - ether (200m And extracted with L × 3). The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure to obtain a crude product of a brown solid. By purifying this product by a silica gel column (hexane), 2-bromo-5-chloro-1,3-difluorobenzene as a yellow oil (21.4 g, yield: 81%) was obtained.
