Green, effective and chromatography free synthesis of benzoimidazo[1,2-a]pyrimidine and tetrahydrobenzo [4,5]imidazo [1,2-d]quinazolin-1(2H)-one and their pyrazolyl moiety using Fe3O4@SiO2@l-proline reusable catalyst in aqueous media

Abstract

l-proline-functionalized silica-coated Fe3O4 nanoparticle was synthesized and characterized using Fourier Transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), Zeta potential and a vibrating sample magnetometer (VSM). The Fe3O4@SiO2@l-proline nanoparticles in aqeous media have been used as a green avenue for the mild and efficient multicomponent synthesis of new derivatives of benzoimidazo[1,2-a]pyrimidines and tetrahydrobenzo [4,5]imidazo-[1,2-d]quinazolin-1(2H)-ones in excellent yields. Furthermore, the recovery and reuse of the catalyst was demonstrated 10 times without a detectible loss in activity. Eco-friendliness, high purity of the desired products, short reaction time and easy workup can be mentioned as the other advantages of this method.