Synthesis, characterization and antibacterial activity of some heterocyclic compounds containing tetrazole, imidazolidine and thiazolidine

Background: Antibiotic resistance represents a growing threat to public health, requiring the development of new and effective compounds. This study aimed to synthesize, characterize, and evaluate the antibacterial activity of a series of heterocyclic compounds (tetrazole, imidazolidine, and thiazolidine). Methods: The compounds were synthesized via sequential reactions, starting with the condensation of 2-aminothiazole with 2-hydroxy-4-nitrobenzaldehyde to form compound (1), followed by Schiff base formation (2), and further cyclization reactions using sodium azide, thioglycolic acid, glycine, alanine, and tryptophan to produce compounds (3–7). Structural characterization was performed using FTIR, 1H NMR, 13C NMR, while the antibacterial activity against Staphylococcus aureus and Escherichia coli was tested. Results: The target compounds (3–7) were successfully synthesized and their structures confirmed. Compound (6), derived from tetrazole, demonstrated significant inhibitory activity, with an inhibition zone of 10 mm against S. aureus. Other derivatives exhibited notable selectivity towards Gram-positive bacteria.The results confirm the promising potential of tetrazole compounds, especially compound (6), as candidates for the development of novel antibacterial agents against Gram-positive bacteria,