Unequivocal synthesis of substituted thiazolo[3,2-a]benzimidazoles

Abstract

An unequivocal route to individual substituted thiazolo[3,2-a]benzimidazole isomers has been developed, involving the acid-catalyzed intramolecular condensation of dialkylacetals with the sulfur atom of benzimidazole-2-thiones. Products are isolated without isomerization, in contrast to several literature methods.