Under nitrogen protection, 3,6-dibromocarbazole (5 g, 15.4 mmol), phenylboronic acid (4.1 g, 33.9 mmol), palladium triphenylphosphine (0.7 g, 0.6 mmol) and toluene (45 ml) were sequentially added to a dry reaction flask. Subsequently, 2M aqueous sodium carbonate solution (45 ml) was slowly added. The reaction mixture was stirred at 80°C for 8 hours. After completion of the reaction, the organic phase was separated and concentrated under reduced pressure using a rotary evaporator. Finally, the concentrated residue was purified by silica gel column chromatography to afford the target product 3,6-diphenylcarbazole (3.6 g, 74% yield).
