Bromide ion → 3-Bromo-1h-indole

Participants

Reaction Steps

To a solution of the above bromide (1.09 g, 2.8 mmol) in benzene (60 mL) and N-methylpyrrolidinone (6 mL) was added 4,4′-dimethoxybenzhydrol (818 mg, 3.4 mmol) and p-toluenesulfonic acid (532 mg, 2.8 mmol), and the mixture was heated to reflux. After 24 hours the reaction was cooled to room temperature and diluted with ethyl acetate (200 mL). The organic layer was washed with NaHCO3 (2×), H2O (2×), and brine(2×). The organic layer was dried over anhydrous MgSO4, filtered and solvent was removed in vacuo. The crude material was purified via column chromatography (10% EtOAc-hexane) to provide the desired DMB protected 3-bromo indole derivative (1.5 g, 2.4 mmol, 87% yield) as an orange solid: (MS m/z (M+H) 615, 617).

Provenance & Evidence