Benzimidazole → HCID 22727953, compound

HRID 2086084Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4]2[N:10]=[CH:9][N:8]([C:11]3[CH:16]=[CH:15][CH:14]=[C:13]([O:17]C)[CH:12]=3)[C:5]2=[N:6][CH:7]=1.N1C2C=CC=CC=2NC=1>Br.C(O)(=O)C.[OH-].[Na+]>[Br:1][C:2]1[CH:3]=[C:4]2[N:10]=[CH:9][N:8]([C:11]3[CH:12]=[C:13]([OH:17])[CH:14]=[CH:15][CH:16]=3)[C:5]2=[N:6][CH:7]=1

Participants

Conditions

Temperature: 100 °C

Procedure

A suspension of 6-bromo-3-(3-methoxyphenyl)-3H-imidazo[4,5-b]pyridine (10.7 g, 35 mmol) in hydrobromic acid (80 ml of a 30 wt. % solution in acetic acid) was heated at 100° C. for 20 hours. After cooling to ambient temperature the reaction mixture was slowly dissolved in excess 3N sodium hydroxide, keeping the temperature <20° C. (to prevent hydrolysis of the benzimidazole back to the bis-amine). The aqueous phase was extracted with ether (×2) then adjusted to pH 7 with concentrated hydrochloric acid. The resulting solid was collected by filtration, washed with water and dried under high vacuum to give 3-(6-bromoimidazo[4,5-b]pyridin-3-yl)phenol as a beige-coloured solid (10.2 g, 99%); δH (400 MHz, d6-DMSO) 6.88 (1H, ddd, J 8, 2 and 1), 7.28 (1H, ddd, J 8, 2 and 1), 7.35-7.41 (2H, m), 8.52 (2H, dd, J 11 and 2), 8.91 (1H, s), 9.96 (1H, br s); m/z (ES+) 290 and 292 (M++H).

Workup

temperatureAfter cooling to ambient temperature the reaction mixture
customthe temperature <20° C.
extractionThe aqueous phase was extracted with ether (×2)
filtrationThe resulting solid was collected by filtration
washwashed with water
customdried under high vacuum

Sources & evidence

ORD record: ord-fe7879da0deb42229675fd9724d5ff65
Source dataset: uspto-grants-2004_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06723735B1

Reaction notes

Loading…