Diphenylamine (37.0 g, 218.64 mmol) was added to a round bottom flask and dissolved in toluene (1100 mL),
and 1-bromo-3-chlorobenzene 41.86 g, 218.64 mmol), Pd2(dba)3 (6.01 g, 6.56 mmol), P(t-Bu)3 (2.65 g, 13.12 mmol),
NaOt-Bu (63.03 g, 655.9 mmol) were added in the order and stirred at 100 ° C. After the reaction was completed, the
reaction mixture was extracted with ether and water. The organic layer was dried over MgSO4 and concentrated. The
resultingcompound wasseparated bysilicagelcolumn chromatography andrecrystallized to obtain47.6 g ofthe product.
(yield: 78%)