Fabrication of [Fe₃O₄@SiO₂@Si-(CH₂)₃-Bipyr][ZnₓClᵧ] as a Novel Magnetic Catalyst, and Its Utility for Construction of 𝐵𝑖𝑠-Coumarins and 𝐵𝑖𝑠(Pyrazolyl)Methanes

Initially, a novel magnetic catalyst namely [Fe۳O۴@SiO۲@Si-(CH۲)۳-Bipyr][ZnxCly] (FSCBZ) was fabricated, and its structure was corroborated using energy-dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric (TG), and vibrating-sample magnetometery (VSM) analyses. In continue, it was employed to catalyze the solvent-free construction of bis-coumarins (from aryl aldehydes and ۴-hydroxycoumarin) and bis(pyrazolyl)methanes (from aryl aldehydes and ۳-methyl-۱-phenyl-۱H-pyrazol-۵(۴H)-one). The coumarin and pyrazole derivatives were attained in short times (۱۰-۲۰ min) and high yields (۸۹-۹۸%). FSCBZ was reusable for two times with retaining its catalytic performance.

Keywords:

Magnetic catalyst , [Fe₃O₄@SiO₂@Si-(CH₂)₃-Bipyr][ZnₓClᵧ] , 𝐵𝑖𝑠-coumarin , 𝐵𝑖𝑠(pyrazolyl)methane , ۴-Hydroxycoumarin , ۳-Methyl-۱-phenyl-۱𝐻-pyrazol-۵(۴𝐻)-one