To a solution of 4-nitro-1H-pyrazole (113 mg, 1 mmol, 1.0 eq.) in acetonitrile (5 mL) was added 2-bromoethyl methyl ether (138 mg, 1 mmol, 1.0 eq.) and potassium carbonate (276 mg, 2 mmol, 2.0 eq.) in that order. The reaction mixture was stirred at 80 °C for 4 hours. After completion of the reaction, the reaction mixture was diluted with ethyl acetate (100 mL) and washed with water (50 mL × 2). The organic layers were combined, concentrated and purified by silica gel column chromatography (petroleum ether/ethyl acetate = 10:1) to afford 1-(2-methoxyethyl)-4-nitro-1H-pyrazole (170 mg, yield: 100%) as a colorless oil.ESI-MS (M + H): 172.1.1 1H NMR (400 MHz, CDCl3) δ: 8.23 (s, 1H) , 8.07 (s, 1H), 4.31 (t, J = 5.2 Hz, 2H), 3.74 (t, J = 5.2 Hz, 2H), 3.35 (s, 3H).
