Cs-ECH-TMA: A novel and efficient catalyst for green synthesis of polyhydroquinolines and acridinediones

Here, an efficient and biodegradable catalytic system prepared through a simple procedure is presented by using chitosan (Cs), epichlorohydrin (ECH) and trimesic acid (TMA). The obtained bio-based Cs/ECH-TMA was characterized by using energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) and FT-IR analysis. The Cs-ECH-TMA biopolymeric materials were used, as a bifunctional heterogeneous and green catalyst, for efficient synthesis of biologically-active scaffolds including polyhydroquinolines (PHQs) and polyhydroacridinones (PHAs) through Hantzsch reaction in a one-pot reaction. Both PHQs and PHAs were synthesized in the presence of heterogeneous Cs/ECH-TMA catalyst from their corresponding substrates in EtOH under reflux conditions in high to quantitative yields. The Cs/ECH-TMA catalyst is recyclable and can be reused at least four times.