Tetrakis(triphenylphosphine)palladium (0.24 g, 0.21 mmol) and potassium carbonate (1.72 g, 12.6 mmol) were added to a solvent mixture of THF and water (5:1, v/v) as 2,6-dibromopyridine (1 g, 4.2 mmol) and 4-formylphenylboronic acid (0.7 g, 4.64 mmol). The reaction mixture was stirred at 70 °C for 12 h and the reaction progress was monitored by TLC. After completion of the reaction, the mixture was extracted with dichloromethane and the organic phase was dried with anhydrous sodium sulfate. Purification by column chromatography (silica gel 60-120 mesh, eluent hexane/ethyl acetate, 4:1, v/v) afforded the target product 4-(6-bromopyridin-2-yl)benzaldehyde as a solid [29].
