Synthesis, characterization, and bioassay of a new class of pyrazolyl/isoxazolyl oxadiazoles

This study aimed at describing a simple and facile synthesis of pyrazolyl/isoxazolyl 1,3,4-oxadiazole derivatives from the synthetic intermediates pyrazolyl/isoxazolyl carboxylates adopting conventional and ultrasound irradiation methods. In fact ultrasound-promoted synthesis led to the formation of title compounds in higher yields and in shorter reaction times when compared with conventional methods. All the compounds were characterized by IR, 1 H NMR, 13 C NMR, and mass spectra. The synthesized compounds were evaluated for their antioxidant and anti-inflammatory activities. The bioassay results indicated that some title compounds were found to be more potent than standard drugs. Amongst all the tested compounds furanyl/pyridinyl linked pyrazolyl/isoxazolyl methoxyphenylsulfonylmethyloxadiazoles were identified as potential antioxidant and anti-inflammatory agents. Graphical abstract