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

HRID 2180156Notes

Reaction equation

B(Br)(Br)Br.C[O:6][C:7]1[CH:8]=[C:9]2[CH:15]=[C:14]([CH3:16])[NH:13][C:10]2=[N:11][CH:12]=1.[OH-].[Na+].Cl>C(Cl)Cl>[CH3:16][C:14]1[NH:13][C:10]2=[N:11][CH:12]=[C:7]([OH:6])[CH:8]=[C:9]2[CH:15]=1

Participants

Conditions

Temperature: -30 °C

Procedure

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).

Workup

waitThe mixture was left
customto warn up to ambient temperature
additionThe mixture was poured onto ice
extractionThe mixture was extracted with ethyl acetate
washThe organic layer was washed with water
dry with materialdried (MgSO4)
filtrationfiltered
customthe filtrate was evaporated
customThe residue was purified by column chromatography
washeluting with with methylene chloride
additionThe fractions containing the expected product
customevaporated

Sources & evidence

ORD record: ord-67abdcb0754d45f4afe4e255e6fca382
Source dataset: uspto-grants-2005_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06887874B2

Reaction notes

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