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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. [ABSTRACT FROM AUTHOR]

2-(2-Furyl)-1 H-naphto[2,3- d]imidazole was synthesised by interaction of 2,3-diaminonaphtalene with furfural in the conditions of Weidenhagen reaction. At its N-methylation in the KOH-DMSO system the 1-methyl-2-(2-furyl)-1 H-naphto[2,3- d]imidazole was obtained, which we subjected to reactions of electrophilic substitution (nitration, bromination, sulfonation, formylation, and acylation). This compound possesses a specific reactivity: all reactions, as a rule, proceed at the naphthalene scaffold while the furan ring is not involved. [ABSTRACT FROM AUTHOR]