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

A new method for heterogenization of s-triazine catalyst has been explored by readily preparation of ionic liquid based s-triazine-immobilized silica-coated Fe3O4 magnetic nanoparticles [Fe3O4@SiO2-s-triazine]. The structure of newly prepared nanoparticles was characterized by Fourier transform infrared (FT-IR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray (EDX) method, vibrating sample magnetometry (VSM) and thermo gravimetric analysis (TGA).These nanoparticles were identified as an efficient catalyst for the one-pot three-component synthesis of 4,8-dihydro [3,2-b] pyran derivatives in excellent yields.The catalyst was easily separated by magnetic decantation and the recovered nanoparticles were reused for four cycles without any significant loss of catalytic activity.The synthesized dihydropyrano[3,2-b]pyrans were evaluated for their antioxidant and antifungal activities and found to be relatively active