Cu(ii) immobilized on poly(guanidine-sulfonamide)-functionalized Bentonite@MgFe(2)O(4): a novel magnetic nanocatalyst for the synthesis of 1,4-dihydropyrano[2,3-c]pyrazole

In this paper, we aim at synthesizing a new nanocomposite material in which bentonite acts as a nucleation site for MgFe(2)O(4) nanoparticles precipitation in the attendance of an external magnetic field (MgFe(2)O(4)@Bentonite). Moreover, poly(guanidine-sulfonamide), as a novel kind of polysulfonamide, was immobilized on the surface of the prepared support (MgFe(2)O(4)@Bentonite@PGSA). Finally, an efficient and environment-friendly catalyst (containing nontoxic polysulfonamide, copper, and MgFe(2)O(4)@Bentonite) was prepared by anchoring a copper ion on the surface of MgFe(2)O(4)@Bentonite@PGSAMNPs. The synergic effect of MgFe(2)O(4) magnetic nanoparticles (MNPs), bentonite, PGSA, and copper species was observed while conducting the control reactions. The synthesized Bentonite@MgFe(2)O(4)@PGSA/Cu, which was characterized using energy-dispersive X-ray spectroscopy (EDAX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier-transform infrared (FT-IR) spectroscopy, was applied as a highly efficient heterogeneous catalyst to synthesize 1,4-dihydropyrano[2,3-c] pyrazole yielding up to 98% at 10 minutes. Excessive yield, quick reaction time, using water solvent, turning waste to wealth, and recyclability are the important advantages of the present work.