Superparamagnetic Fe3O4@Alginate supported L-arginine as a powerful hybrid inorganic-organic nanocatalyst for the one-pot synthesis of pyrazole derivatives

Hybrid inorganic-organic material Fe3O4@Alg@CPTMS@Arg, was prepared by the layer-by-layer techniques through grafting l-arginine (l-arg) to Fe3O4@Alg using 3-chloropropyltrimethoxysilane (CPTMS) as a linker. Fe3O4@Alg was prepared by in situ co-precipitation of iron (iii) and iron (ii) chloride in the presence alginate (Alg). The hybrid inorganic-organic material was characterized employing various techniques such as Fourier transform infrared (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and vibrating sample magnetometer (VSM). The as-prepared Fe3O4@Alg@CPTMS@Arg nanoparticles mediated the synthesis of pyrazole derivatives withviaone-pot reaction between phenylhydrazine, malononitrile, and various aromatic aldehydes under reflux in ethanol. Recycled catalyst exhibited comparable efficacy after seven cycles. The high catalytic activity, excellent yields, as well as the recyclability of the hybrid nanomaterials with quantitative efficiency, are factors that render this environmentally benign procedure appealing.