Phosphorus oxychloride → 6-bromo-3-chloro-2-(4-fluorophenyl)-2H-indazole

Participants

Reaction Conditions

Reaction Steps

A mixture of compound (xii) (6.44 g, 19.20 mmol) and POCl3 (50 mL) was heated at 95° C. for 6 h. The volatiles were removed under reduced pressure and the residue was basified by the addition of an ice-cold saturated solution of sodium carbonate. The solid obtained was filtered and dried (Na2SO4) to give the crude product which was purified by column chromatography on 100-200 mesh silica gel eluting with EtOAc/hexane (3-5%) to give 6-bromo-3-chloro-2-(4-fluorophenyl)-2H-indazole (xiii) (4 g, 64%) as a white solid. ESI-MS m/z calculated for [M+H]+: 326.95; found: 326.95.

Provenance & Evidence