title: Synthesis and antibacterial activity of 4-aryl-2-(1-substituted ethylidene)thiazoles.
abstract: (E)-4-Aryl-2-[2-(1-substituted ethylidene)hydrazinyl]thiazoles and (Z)-3-substituted-4-aryl-2-[(E)-(1-phenylethylidene)hydrazono]-2,3-dihydrothiazoles were synthesized by the reaction of (substituted ethylidene)hydrazinecarbothioamides with ω-bromoacetophenones. The characterization of this new class of compounds was performed using different spectroscopic tools. The structure of (Z)-3-benzyl-4-(4-bromophenyl)-2-[(E)-(1-phenylethylidene)hydrazono]-2,3-dihydrothiazole 6e was unambiguously confirmed by single-crystal X-ray crystallography. Compounds 5a-e, 5i, 6e, 6g, and 6i were screened for their in vitro antibacterial activity against different strains of microorganisms; most of the tested compounds exhibited promising antibacterial activity against some organisms compared to ciprofloxacin and sulbactam penicillin. Compounds 5e, 5i, 6e, 6g, and 6i exhibited several-fold significant antibacterial activity against the Gram-positive bacteria Staphylococcus aureus, better than ciprofloxacin, with minimum inhibitory concentration values ranging from 0.05 to 0.4 µg/mL. The rest of the tested compounds gave significant antibacterial activities against different Gram-negative bacterial strains.
authors.affiliation: Chemistry Department, Faculty of Science, Minia University, El-Minia, Egypt. alaahassan2001@mu.edu.eg
authors.forename: Alaa A
authors.initials: AA
authors.lastname: Hassan
authors.forename: Yusria R
authors.initials: YR
authors.lastname: Ibrahim
authors.forename: Essmat M
authors.initials: EM
authors.lastname: El-Sheref
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdel-Aziz
authors.forename: Stefan
authors.initials: S
authors.lastname: Bräse
authors.forename: Martin
authors.initials: M
authors.lastname: Nieger
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology; D018360:Crystallography, X-Ray; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D013329:Structure-Activity Relationship; D013407:Sulbactam / Q000494:pharmacology; D013844:Thiazoles / Q000138:chemical synthesis* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D013844:Thiazoles; D002939:Ciprofloxacin; D013407:Sulbactam
keywords: (Substituted ethylidene)hydrazinecarbothioamides; Antibacterial activity; Heterocyclizations; Thiazole derivatives; ω-Bromoacetophenones