General procedure: 2,4,6-trichloropyrimidine (5.5 mL, 48 mmol) was dissolved in anhydrous THF (70 mL) under nitrogen protection, and palladium acetate (0.147 g, 0.64 mmol), triphenylphosphine (0.353 g, 1.28 mmol), 4-methoxybenzeneboronic acid (5 g, 31.9 mmol), and 1 M aqueous sodium carbonate (64 mL, 64 mmol). The reaction mixture was stirred at 60 °C for 6 h. The reaction progress was monitored by TLC. Upon completion of the reaction, the mixture was cooled to room temperature and THF was removed by concentration under reduced pressure with a rotary evaporator.Deionized water (100 mL) was added to the residue and extracted with ethyl acetate (100 mL × 3). The organic phases were combined, washed with saturated sodium chloride solution (100 mL), dried over anhydrous sodium sulfate, filtered and the filtrate concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography (eluent: petroleum ether) to afford 2,4-dichloro-6-(4-methoxyphenyl)pyrimidine as a white solid (5.58 g, 68% yield). Mass spectrum (ESI, positive ion mode) m/z: 255.0 [M + H]+. 1H NMR (400 MHz, CDCl3) δ (ppm): 8.07 (dd, J = 9.4, 2.4 Hz, 2H), 7.60 (s, 1H), 7.08-6.99 (m, 2H), 3.91 (s, 3H).
