A new copper Schiff‐base complex of 3,4‐diaminobenzophenone stabilized on magnetic MCM‐41 as a homoselective and reusable catalyst in the synthesis of tetrazoles and pyranopyrazoles

Abstract

This work discusses the synthesis and characterization of new copper Schiff‐base complex of 3,4‐diaminobenzophenone stabilized on magnetic MCM‐41 as a magnetically reusable catalyst. At first, Fe3O4 magnetic nanoparticles were synthesized via a chemical co‐precipitation method using FeCl2.6H2O and FeCl3.6H2O in basic solution of ammonia. Then magnetic MCM‐41 were synthesized via Fe3O4‐doped into mesoporous channels of MCM‐41. Further a new copper Schiff‐base complex of 3,4‐diaminobenzophenone was supported on magnetic MCM‐41 and was used as a practical and magnetically reusable catalyst in organic reactions such as homoselective synthesis of tetrazole and pyranopyrazole derivatives. This catalyst was characterized by several techniques such as scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), wavelength dispersive X‐ray spectroscopy (WDX), thermogravimetric analysis (TGA), X‐ray powder diffraction (XRD), atomic absorption spectroscopy (AAS), Fourier transform‐infrared spectroscopy (FT‐IR), Brunauer–Emmett–Teller (BET), and vibrating sample magnetomter (VSM). This catalyst display good selectivity, high activity, stability and facile magnetic separation. Therefore, this catalyst can be recycled for several times without significant loss of its catalytic efficiency.