Step B: Synthesis of 1-methyl-1H-indazol-6-amine; A mixture of 1-methyl-6-nitro-1H-indazole (0.480 g, 2.71 mmol), platinum oxide (50 mg), ethanol (20 mL), and tetrahydrofuran (5 mL) was subjected to a hydrogenation reaction apparatus under atmospheric pressure. The reaction was stirred at room temperature for 1.5 hours under hydrogen pressure of 30 psi. Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under reduced pressure to give 1-methyl-1H-indazol-6-amine (0.395 g, 99% yield) as an off-white solid. The product was characterized by 1H NMR (500 MHz, CDCl3): δ 7.80 (s, 1H), 7.48 (d, J = 8.5 Hz, 1H), 6.57 (dd, J = 8.5, 1.8 Hz, 1H), 6.53 (s, 1H), 3.94 (s, 3H), 3.86 (br s, 2H); ESI MS m/z 148 [M + H ]+.
