4,6-Dichloropyrimidine-5-carbonyl chloride (36 g, 170 mmol) was dissolved in tetrahydrofuran (200 mL) under ammonia atmosphere and the reaction was stirred at room temperature. The progress of the reaction was monitored by thin layer chromatography (TLC) until the complete disappearance of the raw material. Upon completion of the reaction, the reaction mixture was concentrated under reduced pressure and the resulting residue was partitioned with ethyl acetate (300 mL) and water (100 mL). The aqueous phase was further extracted with ethyl acetate (100 mL x 2). All organic phases were combined, washed with saturated saline (100 mL), dried over anhydrous sodium sulfate and subsequently concentrated under reduced pressure to give 4,6-dichloropyrimidine-5-carboxamide (27.2 g, yield: 83.2%) as a yellow solid. Mass spectrum (ESI, positive ion mode) m/z: 191.9 [M + H]+; 1H NMR (600 MHz, CDCl3) δ (ppm): 8.85 (s, 1H), 6.23 (br.s, 1H), 5.96 (br.s, 1H).
