Green and efficient synthesis of acridine-1,8-diones and hexahydroquinolines via a KH2PO4 catalyzed Hantzsch-type reaction in aqueous ethanol

A simple, clean, and economical methodology for the synthesis of acridine-1,8-dione and hexahydroquinoline derivatives via Hantzsch-type condensation has been described. This study highlights the development of a new green pathway for the preparation of substituted 1,4-dihydropyridines derivatives. The mild, cheap, and nontoxic potassium dihydrogen phosphate (KH2PO4) is proved to be an efficient catalyst for the above multi-component reaction to get excellent yields. Widely available and mostly benign catalyst, eco-friendly solvent, and easy purification are among the several attractive features.