The general procedure for the synthesis of 5-nitropyrimidin-4(3H)-one from the compound (CAS:64273-40-1) and formamidine hydrochloride was as follows: referring to the preparative scheme in Section 2.8, formamidine hydrochloride 4b (739 mg, 7.1 mmol), sodium methanol (1 M methanol solution, 7.1 mL, 7.1 mmol) and compound 5 (1.34 g, 7.1 mmol) were sequentially added to methanol (50 mL). The reaction mixture was stirred at room temperature for 24 h. Upon completion of the reaction, the light yellow solid product 6b (558 mg, 55.8% yield) was obtained. The product was characterized by the following data: melting point of 154-156 °C; 1H NMR (400 MHz, DMSO-d6) δ 8.89 (s, 1H), 8.53 (s, 1H).
