Synthesis of 2,4,5-trisubstituted imidazoles over reusable CoFe2O4 nanoparticles: an efficient and green sonochemical process

Magnetic nanocatalysts are the most interesting owing to their easy and efficient isolation and recovery with an external magnetic field, which avoids loss of the catalyst associated with filtration or centrifugation and they have been widely applied in organic reactions.1,2Among various magnetic nanoparticle, Cobalt ferrite (CoFe2O4) nanocrystals with spinel structure have attracted much attention because of their outstanding properties, their catalytic properties depend on the tetrahedral and octahedral sites of the spinel structure of ferrite nanoparticles. The imidazole ring is a fertile source of biologically important molecules. Compounds containing imidazole moiety have many pharmacological properties, and play important roles in biochemical processes. Among these imidazoles, 2,4,5-triarylimidazoles can be used as light-sensitive materials in photography and are known as inhibitors, fungicides and herbicides, plant growth regulators, and therapeutic agents.3Here in, we report a simple and high yielding protocol for the synthesis of trisubstituted imidazoles via One-Pot condensation of 1, 2-diketone with aldehyde and NH4OAc using magnetic CoFe2O4 nanoparticles as an eco-friendly heterogeneous catalyst (Figure 1). This method is an efficient and rapid ultrasonic assisted route for the synthesis of wide variety of imidazoles.