Molecular geometry and biological activity of 2-(4-substituted-phenylimino)thiazolidin- 4-one compounds

Abstract

ABSTRACT. A series of 2-(4-substituted-phenylimino)thiazolidin-4-one compounds was synthesized via heterocyclizing the corresponding N-aryl-2-chloroacetamides with ammonium thiocyanate. Their chemical structures were elucidated based on an extensive analysis of their spectroscopic data, including infrared, 1H NMR, 13C NMR, and mass analyses. The possible tautomeric forms of synthesized thiazolidine-4-ones were studied. The tautomerization equilibrium parameters, ΔH, ΔG, and Keq were calculated using the DFT/B3LYP methodology, where it has been indicated that the tautomeric form, phenylimino, is more favourable than the phenylamino form. The antibacterial and antioxidant properties of the synthesized thiazolidin-4-ones were investigated. 2-(Chlorophenyl-imino)thiazolidin-4-one displayed  potent antibacterial  activity against E. coli (88.46%) and S. aureus (91.66%), and  highest percent of inhibition (81.8%, ABTS assay).   KEY WORDS: N-aryl-2-chloroacetamides, Ammonium thiocyanate, 2-(Arylimino)thiazolidin-4-ones, Mulliken’s charges, Dipole moment, ABTS assay Bull. Chem. Soc. Ethiop. 2023, 37(5), 1275-1286.                                                            DOI: https://dx.doi.org/10.4314/bcse.v37i5.18