Study of the Catalytic Activity of Zr(HPO4)2 in the Synthesis of Hexahydroquinoline Derivatives under Solvent-free Conditions

The quinoline core structure is an important heterocyclic feature that can be found in numerous biologically active componds which exhibit a vast range of pharmacological properties such as antimalarial [1], antibacterial [2], antimicrobial [3], and antistaphylococcal activities [4]. Meanwhile, an important class of antibiotics possesses a 4-quinolone framework in their structure [5], and also several 2,4-disubstituted polyhydroquinolines exhibit promising in vivo antihyperglycemic activity [6]. Recently, inorganic acidic salts have attracted the attention of researchers in organic surface chem-