Synthesis and Antimicrobial Activity of 4-Substituted 1,2,3-Triazole-Coumarin Derivatives

Abstract

A new series of coumarin-1,2,3-triazole conjugates with varied alkyl, phenyl and heterocycle moieties at C-4 of the triazole nucleus were synthesized using a copper(I)-catalysed Huisgen 1,3-dipolar cycloaddition reaction of corresponding <i>O</i>-propargylated coumarin (<b>3</b>) or <i>N</i>-propargylated coumarin (<b>6</b>) with alkyl or aryl azides. Based on their minimal inhibitory concentrations (MICs) against selected microorganisms, six out of twenty-six compounds showed significant antibacterial activity towards <i>Enterococcus faecalis</i> (MIC = 12.5-50 µg/mL). Moreover, the synthesized triazoles show relatively low toxicity against human erythrocytes.