Sodium carbonate (Na2CO3, 0.49 g, 4.62 mmol) was added to a methanol (MeOH, 30 mL) solution of 2-methylthio-4,6-dichloro-5-nitropyrimidine (1.0 g, 4.16 mmol) and the reaction mixture was stirred at room temperature. After the reaction was carried out for 6 h, the reaction was terminated by adding water (H2O, 150 mL) and the resulting precipitate was collected by filtration. The precipitate was dried and purified by hexane crystallization to give 4-chloro-6-methoxy-2-(methylthio)-5-nitropyrimidine as a colorless solid. Yield: 0.63 g (64%); Melting point: 78-79°C (literature value: 77.5-79.5°C).1H NMR (300 MHz, CDCl3): δ= 2.60 (s, 3H, SCH3), 4.13 (s, 3H, OCH3).13C NMR (75 MHz, CDCl3): δ= 14.8, 56.2, 128.8, 151.4, 160.9, 173.8. elemental analysis (C6H6ClN3O3S) calculated values: C, 30.58; H, 2.57. measured values: C, 30.75; H, 2.54.
