Expeditious mechanochemical conversion of dihydronaphthalenyl-N-phenylhydrazine-1-carbothioamides into hydrazono-thiazolidin-4-one and hydrazono-dihydrothiazole derivatives—Spectroscopic, DFT, X-ray diffraction, and antibacterial studies

This study reports a facile mechanochemical conversion of N-phenylthiosemicarbazone derivatives of 1-tetralone analogs into thiazolidin-4-ones, thiazolidin-5-ylidene-acetates, and dihydrothiazoles by their condensation with chloroacetic acid, DMAD, and phenacyl bromide, respectively. Triethylammonium hydrogen sulfate [Et₃NH]⁺ [HSO₄]⁻ is employed as solid catalyst for this prompt and ecological conversion through which the target products are formed within 10–30 minutes in quantitative yields. The products have been characterized on the basis of spectroscopic data. X-ray diffraction studies of thiazolidin-5-ylidene-acetate 5b, supported by DFT calculations of E/Z isomers of 5b, are presented. Compounds 4, 5, and 7 are assayed for their antibacterial prospects against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacterial stains. Some derivatives show highly promising antibacterial activities.