Magnetic nanoparticles supported Schiff-base/copper complex: An efficient nanocatalyst for preparation of biologically active 3,4-dihydropyrimidinones.

A novel magnetic iron oxide supported copper/Schiff-base complex (Cu/SB-Fe3O4) was prepared, characterized and applied as effective nanocatalyst for the synthesis of biologically active 3,4-dihydropyrimidinones. The Cu/SB-Fe3O4 was prepared by chemical attachment of Schiff-base groups on Fe3O4/SiO2 nanoparticles followed by treatment with copper salt under mild conditions. This was characterized with several techniques such as VSM, TGA, EDX, FTIR, TEM and SEM. The Cu/SB-Fe3O4 nanocatalyst was successfully applied in the Biginelli reaction and gave corresponding biologically active 3,4-dihydropyrimidinones in high yield. Furthermore, this noble catalyst was easily recovered using an external magnet and reused eleven times with keeping its efficiency and stability under applied conditions.