Silica-coated magnetite nanoparticles functionalized with sulfosalicylic acid: a highly active and magnetically reusable nanocatalyst for the Biginelli reaction

This study demonstrates the successful synthesis of sulfosalicylic acid-functionalized silica-coated magnetic nanoparticles, referred to as MNPs-SSA, as a reusable heterogeneous acid catalyst through a straightforward process. The material structures were thoroughly validated using a diverse set of spectroscopic, microscopic, and magnetic techniques, such as FT-IR, EDX, XRD, FE-SEM, TEM, TGA, and VSM, ensuring comprehensive examination and confirmation. The catalytic efficiency of this innovative material was evaluated using the one-pot, three-component Biginelli reaction under solvent-free conditions. The enhanced reaction conditions described here facilitate the synthesis of a wide variety of substituted dihydropyrimidinones, resulting in high purity and excellent yields in a short reaction time. Furthermore, the catalyst exhibited remarkable thermal stability and could be easily recovered from the reaction mixture using an external magnetic field, enabling multiple consecutive uses without a significant decrease in its catalytic efficiency.