In a dry reaction flask, 4-chloro-2-methylthiopyrimidine (296 mg, 1.84 mmol) and Fe(acac)3 (32 mg, 0.09 mmol) were dissolved in anhydrous THF (10 mL) and cooled to -30 °C. The reaction temperature was kept at -30 °C for a few minutes. Phenylmagnesium bromide (1 M solution of THF, 4.2 mL, 4.2 mmol) was added slowly and dropwise under nitrogen protection, keeping the reaction temperature at -30 °C. The reaction was carried out at -30 °C. The reaction mixture was stirred at this temperature for 50 min. After completion of the reaction, the reaction was quenched with saturated sodium chloride solution and the aqueous layer was extracted with ether (Et2O). The organic phases were combined, dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. The crude product was purified by fast column chromatography (eluent: hexane/ethyl acetate, 10:1). The fraction containing biphenyl (90 mg) was first collected and subsequently the target product 4-phenyl-2-methylthiopyrimidine was obtained as a light yellow solid (197 mg, 53% yield). The structure of the product was confirmed by 1H NMR and 13C NMR: 1H NMR (300 MHz, CD2Cl2) δ 8.53 (d, 1H), 8.09-8.13 (m, 2H), 7.53-7.48 (m, 3H), 7.39 (d, 2H), 2.63 (s, 3H); 13C NMR (75 MHz, CD2Cl2) δ 173.0, 164.0, 158.0, 136.7, 131.1, 131.0, 129.2, 127.5, 127.4, 112.2, 14.3.
