Synthesis and Antimicrobial Activity of (E)-1-Aryl-2-(1H-tetrazol-5-yl)acrylonitrile Derivatives via [3+2] Cycloaddition Reaction Using Reusable Heterogeneous Nanocatalyst under Microwave Irradiation

Abstract

The magnetically recoverable heterogeneous Fe2O3@cellulose@Mn nanocomposite was synthesized by a stepwise fabrication of Mn nanoparticles on cellulose-modified magnetic Fe2O3 nanocomposites, and the morphology of the nanocomposite was characterized through advanced spectroscopic techniques. This nanocomposite was investigated as a heterogeneous catalyst for the synthesis of medicinally important tetrazole derivatives through Knoevenagel condensation between aromatic/heteroaromatic aldehyde and malononitrile followed by [3+2] cycloaddition reaction with sodium azide. Thirteen potent (E)-1-aryl-2-(1H-tetrazol-5-yl)acrylonitrile derivatives are reported in this paper with very high yields (up to 98%) and with excellent purity (as crystals) in a very short period (3 min @ 120 W) using microwave irradiation. The present procedure offers several advantages over recent protocols, including minimal catalyst loading, quick reaction time, and the utilization of an eco-friendly solvent. Furthermore, the synthesized (E)-1-aryl-2-(1H-tetrazol-5-yl)acrylonitrile derivatives (4b, 4c, and 4m) are shown to have excellent resistance against various fungal strains over bacterial strains as compared to the standard drugs Cefixime (4 μg/mL) and Fluconazole (2 μg/mL).