Step 1: Synthesis of 5-bromo-2-methylmercaptopyrimidine
To a stirred solution of 5-bromo-2-chloropyrimidine (0.3 g, 1.563 mmol) in dimethylformamide (DMF, 10 mL) was slowly added methyl mercaptan (0.1 mL, 1.563 mmol) at room temperature. The reaction mixture was then heated to 50 °C with continuous stirring for 3 hours. The reaction process was monitored by thin layer chromatography (TLC). Upon completion of the reaction, the reaction mixture was quenched by addition of water and extracted with ethyl acetate (EtOAc). The organic phases were combined and dried over anhydrous sodium sulfate (Na2SO4), followed by evaporation of the solvent under reduced pressure to give the crude product. The crude product was purified by silica gel (100-200 mesh) column chromatography using 5% ethyl acetate/hexane as eluent, resulting in purified 5-bromo-2-methylmercaptopyrimidine (0.240 g, 75% yield) as a white solid. Mass spectrometry (MS) analysis showed that [M++1] was 205.1.
