Synthesis of functionalized thiopyrano [2,3-b]quinolines via a cascade reactions catalyzed by magnetic arginine/alginate biocomposite

An effective synthesis of functionalized thiopyrano[2,3-b]quinolines has been described via cascade reactions using superparamagnetic iron oxide nanoparticles (SPIONs) coated with L-arginine (Arg) grafted alginate (Alg) called Fe₃O₄@Alg@CPTMS@Arg. The reaction was performed between commercially available CH acids compounds such as dimedone or malononitrile, and 2-mercapto-quinoline-3-carbaldehydes under green conditions. This efficient method provides a new route for the formation of functionalized three or four fused rings.