3-Methyl-1-(toluene-4-sulfonyl)-1H-indazol-6-ylamine (301 mg, 1.0 mmol) was dissolved in 1,2-dichloroethane (80 ml) and methanol (40 ml) at room temperature. The mixture was heated to 80° C. and then the tetrabutylammonium tribromide (1.0 eq, 482 mg) was added. Stirring was continued for 10 minutes, and then the mixture was partitioned between diethyl ether and saturated aqueous sodium sulfite solution. The organic layer was separated, washed with water, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash chromatography (gradient 9:1 to 4:1 hexanes/ethyl acetate) to give 5-bromo-3-methyl-1-(toluene-4-sulfonyl)-1H-indazol-6-ylamine (280 mg, 73.7%) as a white powder.
