In order to generate hybrid antimicrobial remedies with novel mode of action, two series of quinoline based
1,3,4-oxadiazole derivatives condensed with N-aryl/benzothiazolyl acetamides were synthesized and the MIC values of
the compounds towards eight reference bacterial strains (S. aureus, B. cereus, E. coli, P. aeruginosa, K. pneumoniae, S.
typhi, P. vulgaris, S. flexneri), four fungi (A. niger, A. fumigatus, A. clavatus, C. albicans) and Mycobacterium tuberculosis
H37Rv were assayed in vitro. Quinoline–6–carboxlic acid was treated with thionyl chloride in refluxing methanol to
obtain the corresponding ester derivative to be hydrazinolyzed by 99% hydrazine hydrate in ethanol to produce carbohydrazide
intermediate. The carbohydrazide precursor underwent cyclization by carbon disulfide and ethanolic KOH to construct
5–quinolinyl–6–yl–1,3,4–oxadiazol–2–thiol. Substituted 2–chloro–N–phenyl(benzothiazolyl)aceta-mide derivatives
were then condensed to 1,3,4-oxadiazole nucleus via sulphur linkage to yield the desired products. Target products bearing
N–benzothiazolyl–2–chloroacetamides displayed good inhibitory potential. The biological screening identified that
many final analogues exhibited a significant inhibition of the growth of microorganisms at 3.12-25 μg/mL of MIC, which
were comparable to control drugs. The influence of the presence of various functional groups to the phenyl/benzothiazolyl
ring on activity profiles was investigated. The proposed structures of the newly prepared products were confirmed with
the aid of IR, 1H NMR, 13C NMR spectroscopy and elemental analysis. These results may provide new insights in the design
of a novel pool of bioactive templates.