An efficient synthesis of perhydro[1,2,4] triazolo [1,2-a][1,2,4] triazole-1,5-dithiones catalyzed by TiO2-functionalized nano-Fe3O4 encapsulated-silica particles as a reusable magnetic nanocatalyst

摘要

Immobilization of a nano-TiO2 catalyst on the surface of a magnetic SiO2 support was performed through the reaction of a Fe3O4@SiO2 composite with Ti(OC4H9)(4) via a simple process. The Fe3O4@SiO2-TiO2 nanocomposite was characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and a vibrating sample magnetometer (VSM). The Fe3O4@SiO2-TiO2 nanocomposite has been found to be an efficient catalyst for the synthesis of perhydro[1,2,4] triazolo[1,2a][1,2,4] triazole-1,5-dithiones from the condensation of various aldazines and potassium thiocyanate in acetonitrile solvent at room temperature. It has been found that the nanocatalyst was recycled for up to 6 cycles with minimal loss in catalytic activity. The purpose of this research was to provide an easy method for the synthesis of perhydrotriazolotriazole derivatives by a robust and magnetically recoverable catalyst.