synthesis and antibacterial activities of novel imidazo[2,1-b]-1,3,4-thiadiazoles合成及抗菌活性的新型咪唑并[2,1 b]1,3,4-thiadiazoles.pdf

Molecules 2011, 16, 5496-5506; doi:10.3390/molecule OPEN ACCESS molecules ISSN 1420-3049 /journal/molecules Article Synthesis and Antibacterial Activities of Novel Imidazo[2,1-b]-1,3,4-thiadiazoles Kamal F. M. Atta *, Omaima O.M. Farahat, Alaa Z. A. Ahmed and Mohamed G. Marei Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia P.O. Box 426, Alexandria 21321, Egypt * Author to whom correspondence should be addressed; E-Mail: prof.kf_atta@; Tel.: 002035917883; Fax: 002035932488. Received: 18 March 2011; in revised form: 2 June 2011 / Accepted: 7 June 2011 / Published: 28 June 2011 Abstract: 2-Amino-5-(2-aryl-2H-1,2,3-triazol-4-yl)-1,3,4-thiadiazoles 2-4 have been synthesized by the reaction of 2-aryl-2H-1,2,3-triazole-4-carboxylic acids 1 with thiosemicarbazide. Their reaction with phenacyl (p -substituted phenacyl) bromides led to formation of the respective 6-aryl-2-(2-aryl-2H-1,2,3-triazol-4-yl)imidazo[2,1-b]-1,3,4- thiadiazoles 5. Reactivity of the latter fused ring towards reaction with different electrophilic reagents afforded the corresponding 5-substituted derivatives 6-8. The structure of the above compounds was confirmed from their spectral characteristics. Some of these compounds were found to possess slight to moderate activity against the microorganisms Staphylococcus aureus, Candida albicans, Pseudomonas aeruginosa, and Escherichia coli . Keywords: 1,3,4-thiadiazole;