75833-38-4

7460-56-2

75833-38-4

General procedure for the synthesis of 2-chloro-4-cyanopyrimidine from 2-hydroxypyrimidine-4-carbaldehyde oxime: (Step 7) A mixture of 2-oxo-1,2-dihydropyrimidine-4-carboxaldehyde oxime (72.6 g) in cold (0°C) phosphorochloride (280 ml) was placed under vigorous stirring and slowly heated until the onset of a vigorous reaction was observed, at which point heating was stopped. After the reactants were completely dissolved, N,N-diethylaniline (36.3 mL) was added and the reaction mixture continued to reflux for 30 minutes. Upon completion of the reaction, it was cooled to room temperature and the phosphoryl chloride was evaporated under reduced pressure. The crude product was quenched with ice water (500 mL) and extracted with dichloromethane (5 x 200 mL). The organic phases were combined, dried over anhydrous sodium sulfate and subsequently concentrated. The residue was purified by short silica gel column chromatography (dichloromethane as eluent). After concentration, the product 2-chloro-4-cyanopyrimidine (63 g, solidified on standing, 86.5% yield) was obtained and used directly in the next reaction.