The preparation of [1,2,4]triazolo[1,5-a]pyrimidines catalyzed by Schiff base zinc(ii) complex supported on magnetite nanoparticles under mild conditions

Abstract

Nano-[CuFe₂O₄@SiO₂/propyl-1-(O-vanillinaldimine)][ZnCl₂] was prepared by placing a Schiff base zinc(II) complex on a magnetite core and fully characterized by various analyses such as FT-IR, FE-SEM, EDAX, SEM-coupled EDX, TGA, VSM and TEM. The complexes supported on silica-coated magnetite copper ferrite nanoparticles were used as a reusable catalyst for the synthesis of 5-methyl-N,7-diphenyl-4,7-dihydro-[1,2,4]triazolo[1,5-a] pyrimidine-6-carboxamides resulting in 40% to 96% yield in the reactions of various aldehydes, acetoacetanilide, and 3-amino-1,2,4-triazole at 60 °C under solvent-free conditions. The zinc complex can change its structure from tetrahedral to square planar and catalyze the reaction. Some products containing the benzyloxy moiety are new and have been reported for the first time.