The general procedure for the synthesis of N-(4-bromophenyl)-N,N-bis(1,1'-biphenyl-4-yl)amine from p-bromoiodobenzene and bis(4-biphenyl)amine was as follows: bis(4-biphenyl)amine (23.7 g, 73.8 mmol) was added to a round-bottomed flask, followed by the addition of p-bromoiodobenzene (20.9 g, 73.8 mmol), sodium tert-butanolate (10.7 g, 111 mmol), p-butylpropanol (0.33 g, 1.47 mmol), and ultrasonically deoxygenated toluene (1.5 L). 111 mmol), palladium acetate (0.33 g, 1.47 mmol), and ultrasonically deoxygenated toluene (1.5 L). The mixture was heated to reflux overnight under nitrogen protection. After completion of the reaction, the reaction solution was cooled and extracted with ethyl acetate and water. The organic layer was separated and dried with anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure to give the crude product. The crude product was purified by column chromatography using silica gel as stationary phase and dichloromethane/hexane as eluent to afford the target product N-(4-bromophenyl)-N,N-bis(1,1'-biphenyl-4-yl)amine (28.8 g, 82% yield).
