Synthesis of Novel Benzimidazolyl-substituted Acrylonitriles and Amidino-substituted Benzimidazo[1,2-a]Quinolines

Abstract

A series of novel benzimidazole derivatives 3-10 were synthesized. Benzimidazolyl-substituted acrylonitriles 3 and 4 underwent a photochemical dehydrocyclization reaction to give the corresponding mono-and dicyano-substituted benzimidazo[1,2-a] quinolines 5 and 6. Pinner reaction of these compounds did not give the expected mono-and diamidines, but rather only compounds 7-10, with amido groups at 6-position were isolated. A mechanism for the reaction is proposed. Acyclic compounds 3 and 4, as well as cyclic benzimidazo[1,2-a]quinolines 5-8, exhibit interesting spectroscopic properties and are potential biologically active compounds.

Crystal structure and synthesis of benzimidazole substituted acrylonitriles and benzimidazo[1, 2-a]quinolines

“…General aspects of preparation 2-(1H-benzimidazol-2-yl)-3-(4-bromophenyl)-acrylonitrile 5 and 2-bromo-benzimidazo[1,2-a]quinoline-2-carbonitrile 7 were prepared according to Scheme 1, from 4- Table 1 General and crystal data and summary of intensity data collection and structure refinement for compounds 4-7 bromobenzaldehyde and benzimidazole-2-acetonitrile using earlier described method [26]. Synthesis and some spectroscopic properties of compounds 4 and 6 were published earlier [26].…”

“…The synthesis and spectroscopic characterization of compounds 4 and 6 were already published earlier while compounds 5 and 7 were prepared according to the same synthetic method [26].…”

“…We also report the molecular and crystal structures of two additional compounds [2-(1H-benzimidazol-2-yl)-3-(4-cyanophenyl)-acrylonitrile, 4] and [benzimidazo[1,2-a]quinoline-2,6-dicarbonitrile, 6], whose synthesis and spectroscopic characterization have been published earlier by us too[26].The compounds 4 and 5 crystallize as monohydrates.The molecules of compounds 4 and 5 do not significantly deviate from planarity in the crystalline state, while benzoannulated cyclic benzimidazole derivatives 6 and 7 are essentially planar. The crystal structures of 4 and 5 are characterized by O-HÁÁÁN and N-HÁÁÁO hydrogen bonds between water molecule of crystallization and imidazole NH group as well as CN groups (at 4-phenyl position in 4Fig.…”

Novel aminated benzimidazo[1,2-a]quinolines as potential fluorescent probes for DNA detection: Microwave-assisted synthesis, spectroscopic characterization and crystal structure determination

“…Fused compound 4 was prepared by a previously described method [35], by photochemical dehydrohalogenation of compound 3.…”

A Fluorimetric Method Based on an Imidazole Compound for Cu2+ Determination in Tap Water

“…e structural properties of these compounds also make them fluorescent compounds. However, there are a limited number of studies on the fluorescence properties of benzimidazole compounds [16][17][18][19][20][21].…”