Synthesis and Biological Evaluation of Benzo[ b ]thiophene Acylhydrazones as Antimicrobial Agents against Multidrug-Resistant Staphylococcus aureus .

The benzo[ b ]thiophene nucleus and the acylhydrazone functional group were combined to prepare three new series of compounds for screening against Staphylococcus aureus . The reaction of substituted benzo[ b ]thiophene-2-carboxylic hydrazide and various aromatic or heteroaromatic aldehydes led to a collection of 26 final products with extensive structural diversification on the aromatic ring and on position 6 of the benzo[ b ]thiophene nucleus. The screening lead to the identification of eight hits, including ( E )-6-chloro- N '-(pyridin-2-ylmethylene)benzo[ b ]thiophene-2-carbohydrazide ( II.b ), a non-cytotoxic derivative showing a minimal inhibitory concentration of 4 µg/mL on three S. aureus strains, among which were a reference classical strain and two clinically isolated strains resistant to methicillin and daptomycin, respectively.