Oxidation products of fused 2-hetarylimidazole derivatives
摘要:
Oxidation of 5-(1-methyl-1H-benzimidazol-2-yl)thiophene-, and -selenophene-2-carbaldehydes with potassium dichromate in 20% aqueous sulfuric acid afforded the corresponding carboxylic acids. Analogous reaction with 5-(1-methyl-1H-benzimidazol-2-yl)furan-2-carbaldehyde led to the formation of 1-methyl-1H-benzimidazole as a result of decarboxylation of the primary oxidation product and subsequent decomposition of the furan ring. Probable factors responsible for instability of 5-(1H-benzimidazol-2-yl)-hetarene-2-carboxylic acids were considered. The oxidation of 2-furylnaphtho[2,3-d]- and 2-hetarylphenanthro-[9,10-d]imidazoles gave, respectively, an anthraquinone analog and 6,7-quinones. pi-Electron-rich heterocycles in 2-furyl- and 2-pyrrolylphenanthro[9,10-d]imidazoles were oxidized completely, being replaced by hydrogen.
Synthesis of novel fluorescent 2,5-di(benzimidazol-2-yl) derivatives of furan, thiophene, selenophene, and 2,4-di(benzimidazol-2-yl)pyrrole
作者:M. M. El’chaninov、A. A. Aleksandrov
DOI:10.1134/s107036321605039x
日期:2016.5
thienylbenzazoles has shown that 2,5-di(benzimidazol-2-yl)derivatives of five-membered heterocycles with one heteroatom are promising from the viewpoint of requirements to fluorescent dyes and biological fluorescent probes. In the present work, we synthesized the 2,5-dibenzimidazolyl derivatives of furan, thiophene, selenophene and pyrrole.