Bromobenzene (7.71 g, 49.1 mmol), 4,4'-dimethyldiphenylamine (9.78 g, 49.6 mmol), sodium tert-butoxide (5.70 g, 59.3 mmol), palladium acetate (110 mg, 0.490 mmol), tri-tert-butylphosphine (396 mg, 1.96 mmol), and o-xylene (110 mL) were added sequentially under nitrogen protection to a 200 mL three-neck flask equipped with a stirrer. 1.96 mmol) and o-xylene (110 mL). The reaction mixture was stirred at 120 °C for 20 hours. Upon completion of the reaction, 150 mL of pure water was added to the mixture to wash and separate the organic phase. Subsequently, the organic phase was washed with another 150 mL of pure water, followed by washing with saturated saline and separation. The resulting organic layer was concentrated under reduced pressure and the solvent was removed by distillation. The resulting residue was purified by silica gel column chromatography to give 12.9 g of the final white crystalline product 4,4'-dimethyltriphenylamine (96% yield, 99.1% purity).
