Syntheses and insecticidal activities of novel 2,5-disubstituted 1,3,4-oxadiazoles

Nine novel symmetrical and asymmetrical 2,5-disubstituted 1,3,4-oxadiazoles have been synthesized by a facile and mild method with high yield. Meantime, it was found that the fluorine was easy substituted by hydrazine in polyhalogen-substituted aroyl hydrazine. The preliminary bioassay tests show that two of the compounds (D5 and D6) exhibited a significant insecticidal activity (LC50=116.02 and 70.93 mg l−1) on armyworm, Leucania separata Walker. Using the Drug Discovery Workbench (DDW) (Cerius2), structure–activities relationship was studied.