Synthesis and Antimicrobial Evaluation of Novel Homologous Series of N-Aryl-2-{4-[(2,6-dichloro-9H-purin-9-yl)methyl]-1H-1,2,3-triazol-1-yl}acetamides

A new homologous class of 1,2,3-triazole–purine hybrids—N-aryl-2-{4-[(2,6-dichloro-9H-purin-9-yl)methyl]-1,2,3-triazol-1-yl)acetamides—was synthesized via copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) of N-aryl-2-azidoacetamide derivatives to 2,6-dichloro-9-(prop-2-yn-1-yl)-9H-purine. The structure of the synthesized compounds was confirmed by IR and NMR (1H and 13C) spectroscopy and mass spectrometry. The products were screened for antimicrobial activity against Gram-positive (Bacillus subtilis, Staphylococcus aureus, and Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria, as well as Aspergillus niger, Candida albicans, and Aspergillus flavus fungi. Two of them (Ar = 4-nitrophenyl and 4-ethylphenyl) exhibited superior antibacterial and antifungal properties, demonstrating minimum inhibitory concentrations (MICs) as low as 3.125 µg/mL against B. subtilis and A. niger, respectively. These results suggest that purine-triazole hybrids show promise as potential antibacterial agents.