Investigations in the field of the chemistry of 2-hetarylbenzimidazoles. 6. Synthesis and properties of 1-methyl-2-(2′-selenienyl)benzimidazole
Abstract2-(2′-Selenienyl)benzimidazole has been synthesized by a Weidenhagen reaction and converted into the N-methylated derivative. Electrophilic-substitution reactions (nitration, sulfonation, bromination, chloromethylation, and acylation) in the selenophene ring have been studied. It has been shown that the substituent enters the α position of the selenophene ring in most cases. The bromination of 1-methyl-2-(2′-selenienyl)benzimidazole in acetic acid produces the 3′,5′-dibromo derivative, whereas 1-methyl-5(or 6)-bromo-2-(3′,5′-dibromo-2′-selenienyl)benzimidazole is obtained in polyphosphoric acid.