Under nitrogen protection, 5 g (31.3 mmol) of 2-chloro-5-nitropyrimidine was dissolved in 50 mL of tetrahydrofuran (THF) and the solution was cooled to 0 °C. Subsequently, 2.26 g (32.3 mmol) of sodium methanethiol was added to the solution. The reaction mixture was stirred at room temperature for 24 h. The reaction process was monitored by liquid chromatography-mass spectrometry (LCMS) to confirm the formation of 2-(methylthio)-5-nitropyrimidine. Upon completion of the reaction, the mixture was diluted with 250 mL of ether to induce precipitation of the solid. The solids were separated by filtration and washed with dichloromethane. Finally, the filtrate was concentrated under reduced pressure to afford 5.3 g (99% yield) of the target compound 2-(methylthio)-5-nitropyrimidine.
