Aqua-mediated synthesis of acridinediones with reusable silica-supported sulfuric acid as an efficient catalyst

A simple approach to the synthesis of acridinediones via one-pot three-component condensation of an aromatic aldehyde, 5,5-dimethyl-1,3-cyclohexanedione (dimedone), and ammonium acetate or p-toluidine in water with use of silica-supported sulfuric acid as an efficient catalyst is described. Excellent yields, catalyst recovery and reusability, and easy work-up are attractive features of this green protocol. All the synthesized acridinediones were characterized on the basis of their melting-points, elemental analysis and spectral data.