Sodium Hydroxide → 5-Bromo-4-fluoro-1H-indazole

Participants

Reaction Steps

To a solution of 4-bromo-3-fluoro-2-methylaniline (20 g, 98.0 mmol) in CH3CO2H (600 mL) was added NaNO2 (8.1 g, 118 mmol) at 10° C. The resulting mixture was stirred at room temperature for 4 hours. Upon completion, aqueous NaOH (50%) was added to the reaction mixture until pH was ˜7-8. The mixture was extracted with EtOAc. The organic layer was dried over Na2SO4 and concentrated in vacuo. The residue was purified by column chromatography on silica gel (0˜40% EtOAc in petroleum ether) affording the title compound (16 g). 1H NMR (300 MHz, DMSO-d6): δ 13.58 (br, 1H), 8.22 (s, 1H), 7.53 (t, 1H), 7.38 (d, 1H).

Provenance & Evidence