Ethyl orthoformate → 6-Bromo-4H-imidazo[4,5-b]pyridine

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of 5-bromopyridine-2,3-diamine (5 g, 26.6 mmol), formic acid (2.5 mL), and triethylorthoformate (70 mL) was heated at 100° C. for 2.5 h. The reaction mixture was cooled to rt and the solid precipitate was collected by filtration, washed with Et2O and dried to afford 6-bromo-3H-imidazo[4,5-b]pyridine as a solid (3.22 g, 61%) which did not require further purification. 1H NMR (300 MHz, DMSO-d6) δ 13.14 (br s, 1H), 8.50 (s, 1H), 8.44 (d, J=2.1 Hz, 1H), 8.31 (d, J=1.9 Hz, 1H). LCMS (ESI) m/z 198 and 200 (M+H)+.

Provenance & Evidence