Background: Oxadiazole fragment is one of the most prevalent structures in biochemicals,
especially in the research of new pesticides. It is necessary to develop new insecticides with a
different mode of action for the treatment of insecticide resistance problems. And, it is worth exploring
the new active insecticidal lead structures with oxadiazole fragments.
Methods: We used a “splicing up” method introducing the trifluoromethyl-oxadiazole moiety to 3-
(ethylsulfonyl)-pyridine structure, and replaced the 6-position on the pyridine ring by different substituted
amines. Then, a series of novel 3-(ethylsulfonyl)-pyridines containing trifluoromethyloxadiazole
moiety were designed and synthesized. All these title compounds were confirmed by 1H
NMR, 13C NMR and ESI-MS.
Results: The primary insecticidal activity results indicated that some of them (A1-A7, A10, A13-
A14) exhibited good mortality against Mythimna separate at 500 mg/L (80-100%), and compounds
A13 and A14 have moderate insecticidal activity against M. separate at 250 mg/L (50-55%).
Conclusion: According to the bioassay studies, the results revealed that compounds A13 and A14
may provide useful information for further designing of efficient insecticides.
Discussion: The bioassay results showed that the designed compounds did not achieve excellent
insecticidal activity by introducing the potential oxadiazole fragment. Therefore, it seems that the
special physicochemical properties of the oxadiazole fragment should be considered in fragment