Thia-Michael addition of 2-[(4-hydroxy-3,5-dimethoxyphenyl)methylidene]hydrazine-1-carbothioamide (1) with maleic anhydride results in the formation of the title compound 2-{[(4-hydroxy-3,5-dimethoxyphenyl)methylidene]hydrazinylidene}-4-oxo-1,3-thiazolidin-5-yl acetic acid 2. The precursor 1 is synthesized by the reaction of 4-hydroxy-3,5-dimethoxybenzaldehyde and thiosemicarbazide in the presence of glacial acetic acid as the catalyst. The structure of the title compound is determined by elemental analysis, FT-IR, 1H-NMR, 13C-NMR and mass spectral data. In order to determine the molecular interactions with the bacterial enzyme, the title compound is further docked into the active site of the MurB protein of Staphylococcus aureus (PDB ID: 1HSK). The in vitro antibacterial and antifungal activity of the title compound is carried out in order to appraise its antimicrobial efficacy by determination of zone of inhibition and minimal inhibitory concentration. The compound is also evaluated for its antioxidant property by 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging assay.

The cyclization reaction of 3-(4-ethoxyphenyl)-1-(naphthalen-1-yl)prop-2-en-1-one (1) using hydrazine hydrate in acetic acid medium culminates, resulting in the title compound 1-[5-(4-ethoxyphenyl)-3-(naphthalen-1-yl)-4,5-dihydro-1H-pyrazol-1-yl]ethan-1-one (2). The structure of the newly synthesized compound is determined by IR, 1 H-NMR, 13 C-NMR and mass spectral data. In order to evaluate the putative molecular interactions, the title compound (2) is docked against the active site of Cytochrome P 450 14α-sterol demethylase (CYP51) from Mycobacterium tuberculosis.