The reaction was carried out with 3-bromo-4-hydroxybenzonitrile (5.0 g, 25.3 mmol), potassium carbonate (7.0 g, 50.1 mmol) and iodomethane (3.9 g, 27.8 mmol) in acetonitrile (20 mL) with stirring for 6 h at 25 °C. The reaction was carried out by thin layer chromatography (TLC). The progress of the reaction was monitored by thin layer chromatography (TLC) and after confirming the completion of the reaction, the reaction mixture was subjected to liquid-liquid separation between ethyl acetate (100 mL) and water (30 mL). The organic phase was collected, washed with brine (20 mL), dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain the crude product. The crude product was purified by fast column chromatography on silica gel to afford 3-bromo-4-methoxybenzenecarbonitrile (4.8 g, 22.6 mmol) in 89% yield using a hexane solution of 30% ethyl acetate as eluent.
