Boron tribromide → 1,3-Dimethyl-6-trifluoromethyl-1H-indol-5-ol

Participants

Reaction Conditions

Reaction Steps

5-Methoxy-1,3-dimethyl-6-trifluoromethyl-1H-indole (725 mg, 3 mmol) in methylene chloride (15 ml) was cooled to zero degrees C., and BBr3 (14.9 ml of a 1 N solution in methylene chloride) was slowly added via syringe. The reaction mixture was stirred 15 minutes at zero degrees C., then allowed to warm to room temperature with stirring for one hour. The reaction mixture was quenched slowly with 75 mL 1 N NaOH. The mixture was acidified to pH 5 with 1 N HCl, extracted with methylene chloride, and the combined organic layers were washed with water, brine, and dried over magnesium sulfate. Solvent was removed under reduced pressure, and the residue was chromatographed (20% EtOAc/Hexanes) to give 235 mg (75%) 1,3-Dimethyl-6-trifluoromethyl-1H-indol-5-ol.

Provenance & Evidence