Chemistry of 2-hetarylbenzimidazoles. 8. Synthesis and properties of 1-methyl-2-(5′-methyl-2′-selenienyl)benzimidazole

Abstract

1-Methyl-2-(5′-methyl-2′-selenienyl)benzimidazole was synthesized and subjected to electrophilic-substitution reactions: nitration, bromination, sulfonation, chloromethylation, formylation, and acylation. The substituent usually enters the 4′ position of the selenophene ring, but nitration with acetyl nitrate leads to a mixture of 5′-nitro and 4′-nitro derivatives. Oxidation of 2-selenienylbenzimidazole with potassium permanganate leads to the 5′-carboxy derivative, while oxidation with selenium dioxide leads to the 5′-hydroxymethyl and 5′-formyl derivatives.