6-Bromo-1H-indazol-3-ylamine

105942-08-3

404827-77-6

Under nitrogen protection, 4-bromo-2-fluorobenzonitrile (5 g, 25.13 mmol) was dissolved in 20 mL of n-butanol, followed by hydrazine hydrate (1.04 mL, 50.26 mmol). The reaction mixture was heated to reflux and kept for 4 hours. Upon completion of the reaction, it was cooled to room temperature and a large amount of solid was observed to precipitate. The solid product was collected by diafiltration and the filter cake was washed with petroleum ether to remove impurities. Finally, the resulting white solid was dried to give 4.759 g of the target product 6-bromo-1H-indazol-3-amine in 85.7% yield.