Ethyl ethyl 2,6-dihydroxy-5-nitropyrimidine-4-carboxylate was dissolved in acetonitrile (50 mL), stirred at room temperature for 30 minutes, trichlorophosphorus was added, warmed to reflux, and the reaction was carried out for 30 minutes, and the progress of the reaction was detected by thin layer chromatography. At the end of the reaction, cooled to room temperature, poured into ice water, stirred, extracted with dichloromethane (50mL3), the organic phase was washed with saturated sodium bicarbonate solution, decolorized by activated charcoal and dried with anhydrous sodium sulfate, filtered, concentrated and then added isopropanol (30mL), heated to dissolve, stirred, a white solid precipitated, left to stand for 2h, filtered, filter cake was dried to obtain the target compound 2,6-dichloro-5- Nitropyrimidine-4-carboxylic acid ethyl ester.
