The general procedure for the synthesis of N-phenylpyridin-4-amine from 4-bromopyridine and aniline was as follows: 3.16 g (20.0 mmol) of 4-bromopyridine, 2.79 g (30.0 mmol) of aniline, 0.37 g (0.4 mmol) of Pd2(dba)3, 0.08 g (0.4 mmol) of PtBu3 and 2.88 g (30.0 mmol ) KOtBu were dissolved in 60 mL of toluene to form a homogeneous solution. Subsequently, the reaction mixture was stirred at 85 °C for 4 hours. After completion of the reaction, the reaction solution was cooled to room temperature and extracted three times with 50 mL of water and 50 mL of diethyl ether. The organic phases were combined, dried with magnesium sulfate, and then the solvent was removed by rotary evaporation. Finally, the residue was separated and purified using silica gel column chromatography to afford 1.49 g of intermediate I-3 in 88% yield. The resulting compound was characterized by LC-MS.
