Hydrochloric Acid → 2-methyl-1H-pyrrolo[2,3-b]pyridin-5-ol

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Reaction Conditions

Reaction Steps

A solution of boron tribromide (64 μl, 0.68 mmol) in methylene chloride (200 l) was added to a solution of 5-methoxy-2-methyl-1H-pyrrolo[2,3-b]pyridine (50 mg, 0.308 mmol) in methylene chloride (4 ml) cooled at −30° C. The mixture was left to warn up to ambient temperature and further stirred for 3 hours. The mixture was poured onto ice. The pH was adjusted to 6.2 with 6N aqueous sodium hydroxide followed by 2 N aqueous hydrogen chloride. The mixture was extracted with ethyl acetate. The organic layer was washed with water, followed by brine and dried (MgSO4), filtered and the filtrate was evaporated. The residue was purified by column chromatography, eluting with with methylene chloride followed by methylene chloride/methanol (98/2 followed by 95/5). The fractions containing the expected product were combined and evaporated to give 2-methyl-1H-pyrrolo[2,3-b]pyridin-5-ol (45 mg, quantitative). 1H NMR Spectrum: (DMSO d6) 2.4 (s, 3H); 5.96 (s, 1H); 7.12 (d, 1H); 7.69 (d, 1H); 8.9 (s, 1H); 11.07 (br s, 1H).

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