A. 4-Iodo-2-methylsulfonylpyrimidine (7 g, 27.5 mmol) and cuprous cyanide (2.46 g, 27.5 mmol) were dissolved in pyridine (150 mL) and heated to reflux for 4 hours. Upon completion of the reaction, the mixture was cooled to room temperature, the reaction solution was concentrated, filtered, and the solids were washed with ether. The filtrate was washed sequentially with water and brine, dried over anhydrous sodium sulfate, filtered and concentrated. The residue was purified by silica gel column chromatography with 10% ethyl acetate-hexane as eluent to give 2-(methylthio)-4-pyrimidinecarbonitrile (3.2 g, 77% yield) as a white solid. Mass spectrum (electrospray positive ion mode) m/z 152 [M + H]+.
