(B) 2-(4,6-dihydroxypyrimidin-2-yl)acetamide (6.28 g, 37.1 mmol) was used as a raw material, which was dissolved in phosphorus trichloride (19 ml, 204 mmol) in a flask equipped with a reflux condenser. N,N-dimethylaniline (10 ml, 79 mmol) was slowly added through the condenser. The reaction mixture was gently heated in an oil bath and quickly removed from the heat source once the reaction was initiated. After the initial vigorous reaction had subsided, the reaction was continued at reflux for 10 min. The hot reaction solution was carefully decanted onto 100 g of ice and the resulting suspension was extracted with dichloromethane (3 x CH2Cl2). The organic layers were combined, dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure. Purification by silica gel column chromatography (SiO2, 15-20% ethyl acetate/hexane) afforded 2-(4,6-dichloropyrimidin-2-yl)acetonitrile (5.10 g, 27.1 mmol, 73%) as a yellow solid.
