Synthesis and reactivity of 2-(furan-2-yl)-1(3)H-imidazo[4,5-b]pyridine

2,3-Diaminopyridine and furfural in the conditions of Weidenhagen reaction give rise to 2-(furan-2-yl)-1(3) H -imidazo[4,5- b ]pyridine, whose methylation in KOH-acetonee system affords isomeric 1-methyl-2-(furan-2-yl)-1 H - and 3-methyl-2-(furan-2-yl)-3 H -imidazo[4,5- b ]pyridines. At the electrophilic substitution of the 1-methyl isomer (nitration, bromination, sulfation, formylation, acylation) depending on the conditions either furan ring, or pyridine fragment suffer the electrophilic attack. At its quaternization with methyl iodide in benzene N-methylpyridinium salt is obtained.