Hypervalent iodine(III) mediated synthesis of novel unsymmetrical 2,5-disubstituted 1,3,4-oxadiazoles as antibacterial and antifungal agents

A series of novel 2,5-disubstituted 1,3,4-oxadiazoles 4 have been conveniently synthesized by oxidative cyclization of pyrazolylaldehyde N-acylhydrazones 3 promoted by iodobenzene diacetate under mild conditions (11 examples, up to 92% isolated yields). All the eleven compounds were tested in vitro for their antibacterial activity against Gram-positive bacteria namely, Staphylococcus aureus, Bacillus subtilis and two Gram-negative bacteria namely, Escherichia coli and Pseudomonas aeruginosa. All the synthesized compounds were also tested for their inhibitory action against two strains of fungus.

Graphical abstractA series of novel 2,5-disubstituted 1,3,4-oxadiazoles 4 have been conveniently synthesized by oxidative cyclization of pyrazolylaldehyde N-acylhydrazones 3 promoted by iodobenzene diacetate under mild conditions (11 examples, up to 92% isolated yields).Figure optionsDownload full-size imageDownload as PowerPoint slide