Synthesis
A mixture of 3-bromo-6-chloro-2-fluorobenzonitrile (BCFBN) (250 mg), ethanol (2.0 mL) and hydrazine hydrate (0.35 mL; 5 eq) was stirred at 80 °C for 1 h. After completion, the solution was allowed to cool to 45 °C and water was added slowly to produce a white precipitate. Following the addition of water, the mixture was stirred for 30 minutes. The solids were isolated via filtration. The solids were washed with water and then dried under vacuum at 45 °C to afford the desired compound 7-Bromo-4-chloro-1H-indazol-3-ylamine (B2.3, 229 mg) in 87% yield.
