50593-24-3

5228-49-9

50593-24-3

Step 2: Preparation of 1-methyl-1H-indazol-5-amine Iron powder (5.04 g, 90.3 mmol) was added batchwise to a mixed solution of ethanol (225 mL) and water (100 mL) of 1-methyl-5-nitro-1H-indazole (4.00 g, 22.6 mmol), followed by ammonium chloride (12.1 g, 225 mmol). The reaction mixture was stirred and heated at 80 °C for 1 hour. After completion of the reaction, the reaction mixture was diluted with dichloromethane (500 mL) and filtered to remove insoluble material. The organic layer was separated, dried with anhydrous magnesium sulfate and concentrated under reduced pressure to give the title compound 1-methyl-1H-indazol-5-amine (3.29 g, 99% yield). HPLC analytical conditions: SYMMETRY C18 column (3.5 μm, 4.6 × 30 mm); mobile phase: acetonitrile/water gradient containing 0.1% trifluoroacetic acid (2%-98% acetonitrile, 10 min); flow rate: 2 mL/min; retention time: 1.06 min. Mass spectrum (MS): m/z 147.2 ([M+H]+).