S-Triazinium-based ionic liquid immobilized on silica-coated Fe3O4 magnetic nanoparticles: an efficient and magnetically separable heterogeneous catalyst for synthesis of 2-amino-4,8-dihydropyrano[3,2-b]pyran-3-carbonitrile derivatives for antioxidant and antifungal evaluation studies

Abstract

We have described a new method to heterogenize s-triazine catalyst by easy preparation of ionic liquid-based s-triazine-immobilized silica-coated Fe3O4 magnetic nanoparticles [Fe3O4@SiO2-s-triazinium chloride]. The structure of the newly prepared nanoparticles was characterized by Fourier transform infrared, X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray method, vibrating sample magnetometery and thermo-gravimetric analysis. These nanoparticles were identified as an efficient catalyst for one-pot three-component synthesis of 4,8-dihydropyrano[3,2-b]pyran derivatives in excellent yields. The catalyst was easily separated by magnetic decantation, and the recovered nanoparticles were reused for four fresh runs without any significant loss of catalytic activity. The synthesized dihydropyrano[3,2-b]pyrans were evaluated for their antioxidant and antifungal activities and found they are relatively active.