ABSTRACT
As benzodiazepines occupy an important place in the realm of medicinal and material chemistry, a facile, ecofriendly, one-pot protocol for the synthesis of 4-substituted-1,5-benzodiazepine derivatives has been described through the one-pot three-component reaction of o-phenylenediamine, dimedone, and aldehydes in the presence of tris(hydrogensulfato) boron [B(HSO4)3] under reflux conditions in aqueous ethanol. The operational simplicity without column chromatographic purification and the avoidance of using hazardous and expensive solvents and catalysts are the most advantages of this method.