To a reaction vial containing an ethanol solution (20 mL) of sodium (0.28 g, 12 mmol) was added 4,6-dichloro-2-(methylthio)pyrimidine (1.95 g, 10 mmol) and stirred at room temperature until the reaction was complete, the progress of the reaction was monitored by thin layer chromatography (TLC). After completion of the reaction, the solvent was removed by evaporation under reduced pressure and quenched by addition of water. Subsequently extracted with dichloromethane (CH2Cl2), the organic phase was washed with water and dried with anhydrous sodium sulfate (Na2SO4). The organic phase was concentrated under reduced pressure and the residue was recrystallized with ether to afford the target compound 6-methoxy-2-methylthio-4-chloropyrimidine (4 g) as a white solid in 70% yield with a melting point of 39-40°C. IR spectra (KBr, cm-1 ): 3003, 2939, 1544, 1328, 1274, 1505, 1030, 820. NMR hydrogen spectra ( 1H NMR, 400 MHz, CDCl3) δ: 2.55 (s, 3H, SCH3), 3.97 (s, 3H, OCH3), 6.41 (s, 1H, pyrimidine-H). Nuclear magnetic resonance carbon spectrum (13C NMR, 100 MHz, CDCl3): δ14.29, 54.52, 102.43, 160.34, 169.90, 172.92. liquid chromatography-mass spectrometry (LC-MS, m/z): 190.0. calculated elemental analysis values (C6H7ClN2OS): C, 37.80; H, 3.70; N 14.69. Measured values: C, 37.72; H, 3.75; N, 14.78.
