Green Synthesis of 4H-pyran Derivatives Using Fe3O4-MNPs as Efficient Nanocatalyst: Study of Antioxidant Activity.

Abstract

In this work, pyran derivatives were synthesized via a multicomponent reaction of ninhydrin, α-haloketones, dialkyl acetylenedicarboxylate, and triphenylphosphine in the presence of iron oxide magnetic nanoparticles (Fe3O4-MNPs) as efficient nanocatalyst in ethanol at room temperature. The biosynthesis of Fe3O4-MNPs was performed by Clover Leaf water extract. In addition, antioxidant activity was examined for the prepared compounds employing DPPH radical scavenging and ferric reduction activity potential (FRAP) experiment and comparing results with synthetic antioxidants (TBHQ and BHT). Compound 5b showed excellent radical trapping activity and good reducing activity relative to standards (BHT and TBHQ). Some advantages of this procedure are: the workup of reaction is easy and the products can be separated easily by filtration. Fe3O4-MNPs display a good improvement in the yield of the product and showed significant reusable activity.