GENERAL STEPS: Cesium carbonate (Cs2CO3, 4.3 g, 13.3 mmol) was added to a stirred N,N-dimethylformamide (DMF, 6 mL) solution of 2-nitro-1H-imidazole (500 mg, 4.42 mmol) under nitrogen protection. Subsequently, iodomethane (Mel, 942 mg, 6.63 mmol) was slowly added to the reaction system. The resulting mixture was stirred and reacted at 50 °C overnight. Upon completion of the reaction, the reaction was quenched with saturated aqueous sodium bicarbonate (NaHCO3) and extracted with ethyl acetate (EA, 25 mL x 3). The organic layers were combined, dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure. The crude product was purified by fast column chromatography (silica gel, eluent: petroleum ether/ethyl acetate, 0-50% gradient) to afford 1-methyl-2-nitro-1H-imidazole (542-1) (530 mg, 100% yield) as a yellow solid. lC-MS (ESI): m/z [M + H]+ 128.1.
