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[摘要]：1-(2-Thienyl)-2-arylazo-4,4,4-trifluorobutane-1,3-diones 4, obtained by the condensation of aryldiazonium salts 2 with 1-(2-thienyl)-4,4,4-trifluoromethyl-1,3-butanedione 3, on treatment with hydroxylamine hydrochloride yielded 3-(2-thienyl)-4-arylazo-5-hydroxy-5-trifluoromethyl-Delta(2)-isoxazolines 5. Subsequently, dehydration of 5-hydroxy-5-trifluoromethyl-Delta(2)-isoxazolines 5 to corresponding 3-(2-thienyl)-4-arylazo-5-trifluoromethylisoxazoles 6 was achieved by treating them with acetic anhydride or EtOH-H2SO4. The structure of the compounds was established on the basis of IR, NMR (H-1, C-13 and F-19), mass spectral studies and elemental analyses. All the compounds were screened for their in vitro antibacterial activity against four pathogenic bacterial strains such as Bacillus subtilis, Staphylococcus aureus (Gram-positive), Pseudomonas fluorescens, Escherichia coli (Gram-negative) and in vitro antifungal activity against two pathogenic fungal strains namely, Candida strain, Saccharomyces cerevisiae. Most of the compounds showed moderate to significant antibacterial activity selectively against Gram-positive bacteria and antifungal activity against S. cerevisiae. (C) 2012 Elsevier B.V. All rights reserved. |
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