Ionic Liquid-Coated Nanoparticles (CaO@SiO2@BAIL): A Bi-Functional and Environmentally Benign Catalyst for Green Synthesis of Pyridine, Pyrimidine, and Pyrazoline Derivatives

Abstract

A novel ionic liquid-coated nanomaterials (CaO@SiO2@BAIL) was successfully synthesized by anchoring the 1-(3-(trimethoxysilyl)propyl)-1,3,5,7-tetraazaadamantan-1-ium chlorozincate (II) bi-functional ionic liquid (BAIL) onto the surface of silica‐coated CaO nanoparticles. The structure of catalyst was characterized using various analytical techniques such as Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), WDS map scan, thermogravimetric (TGA), and inductively-coupled plasma-mass spectrometry (ICP-MS). The performances of prepared hybrid nanomaterial (CaO@SiO2@BAIL) as a catalyst were evaluated for the efficient synthesis of the pharmaceutically valuable heterocyclic compounds. A variety of pyridine, pyrimidine, and pyrazoline derivatives were synthesized in the presence of CaO@SiO2@BAIL within green conditions. The presented method has several advantages such as high yields, low reaction times, and easy preparation of the catalyst. The bi-functional heterogeneous nanocatalyst can be reused at least six times without considerable loss of its catalytic activity.