10472-88-5

7087-65-2

General procedure for the synthesis of 1-bromo-3-fluoro-5-nitrobenzene from 2-bromo-4-fluoro-6-nitroaniline: To a solution of 2-bromo-4-fluoro-6-nitroaniline (702 mg, 3 mmol) in ethanol (3 mL) was added 6 mL of 60% sulphuric acid at 0 °C, followed by the slow addition of sodium nitrite (414 mg, 6 mmol) in batches. After addition, stirring was continued for 1 hour while maintaining the reaction temperature at 0-5 °C. Subsequently, ferrous sulfate heptahydrate (4.38 g, 6 mmol) was added and the resulting mixture was continued to be stirred for 3 hours. After completion of the reaction, the mixture was concentrated, water was added and the aqueous phase was extracted with dichloromethane (20 mL x 3). The organic layers were combined, washed with brine (20 mL), dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by preparative thin layer chromatography (TLC) with the eluent dichloromethane/methanol = 60/1 to afford the target product 1-bromo-3-fluoro-5-nitrobenzene (yellow solid, 448 mg, 68% yield).