Step 1: 5-Bromo-7H-methyl-1H-indazole (2.11 g, 10.0 mmol) and potassium tert-butoxide (1.20 g, 10.7 mmol) were dissolved in 50 mL of tetrahydrofuran (THF) and stirred at room temperature. To this solution, iodomethane (0.700 mL, 11.2 mmol) was slowly added and the reaction mixture continued to be stirred overnight. After completion of the reaction, the precipitate was removed by filtration and the filtrate was concentrated under reduced pressure. The resulting residue was purified by fast column chromatography to afford the target product 5-bromo-1,7-dimethyl-1H-indazole in 1.92 g (43% yield). The product was analyzed by ESI-MS and showed m/z = 225/227 ([M+H]+).
