Synthesis of Benzimidazolo[2,3-b]quinazolinone Derivatives via a One-pot Multicomponent Reaction Promoted by a Chitosan-based Composite Magnetic Nanocatalyst

A practical and green approach for the one-pot multicomponent synthesis of tetraheterocyclic benzimidazolo[2,3-b]quinazolinones has been described via the condensation of 2-aminobenzimidazole or 2-aminobenzothiazole, dimedone, and various aldehydes using Fe3O4@chitosan as an environmentally benign and reusable nanocomposite catalyst in good to excellent yields.