67-56-1

19646-07-2

1333240-17-7

1. Preparation of the compound 2-chloro-4,5-dimethoxypyrimidine: 2,4-dichloro-5-methoxypyrimidine (2.37 g, 13.2 mmol) and potassium carbonate (K2CO3, 1.8 g, 13.2 mmol) were dissolved in methanol (MeOH, 50 mL), and the reaction was stirred for 19 hours at room temperature. After completion of the reaction, the solvent was removed by distillation under reduced pressure. The resulting residue was dissolved in ethyl acetate (EtOAc) and washed sequentially with distilled water and saturated saline. The organic layer was dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure. Subsequently, purification was carried out by silica gel column chromatography with 0 to 20% ethyl acetate/hexane as eluent to afford the target product 2-chloro-4,5-dimethoxypyrimidine as a white solid (1.70 g, 73% yield). The product was characterized by the following data: melting point 65-67 °C; 1H NMR (400 MHz, CDCl3) δ 7.84 (s, 1H), 4.03 (s, 3H), 3.88 (s, 3H); 13C NMR (100 MHz, CDCl3) δ 161.2, 150.0, 141.7, 138.2, 56.6, 55.0.