5228-49-9

GENERAL METHOD: Cesium carbonate (12.26 mmol) was added to a solution of 5-nitroindazole (6.13 mmol) in tetrahydrofuran (THF; 25 mL) at 0 °C. The reaction mixture was stirred at 0 °C for 15 min before iodomethane or allyl bromide (6.13 mmol) was added dropwise. The progress of the reaction was monitored by thin layer chromatography (TLC) until the starting material completely disappeared. After completion of the reaction, the mixture was concentrated. The crude product was dissolved in ethyl acetate (EtOAc; 50 mL), washed sequentially with water and brine, and the organic phase was dried over anhydrous magnesium sulfate (MgSO?). The solvent was removed by evaporation under reduced pressure, and the resulting residue was purified by silica gel column chromatography with ethyl acetate/hexane (3:7, v/v) as eluent to afford 1-alkyl-5-nitroindazole and 2-alkyl-5-nitroindazole, respectively.

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