Synthesis and insecticidal activities and SAR studies of novel benzoheterocyclic diacylhydrazine derivatives.

Two series of novel N'-tert-butyl-N'-substituted benzoyl-N-2,3-dihydrobenzofuran-5-carbohydrazide derivatives were synthesized, their activities and different insecticidal action modes for different Lepidopteral larvicidal assays were evaluated carefully. The results of larvicidal activities against oriental armyworm and mosquito indicate that different benzoheterocyclic analogues of diacylhydrazide have different structure-activity relationships according to the types and patterns of substitution on the benzene, and 3,5-dimethyl is the most efficient substituent for benzoheterocyclic diacylhydrazine. Among them, N'-tert-butyl-N'-(3,5-dimethylbenzoyl)-N-2,4-dimethyl-2,3-dihydrobenzofuran-5-carbohydrazide (Ii) stood out as the best compound with high activity. Compound Ii and N'-tert-butyl-N'-(3,5-dimethylbenzoyl)-N-5-chloro-6-chromanecarbohydrazide (F) have higher contact activities against diamond-back moth and stomach toxicities against cotton bollworm than ANS-118 and JS-118. Compound F has higher contact toxicity against beet armyworm than ANS-118 and JS-118. These results indicate that different heterocycles and substitutents on the benzene rings of benzoheterocyle moiety not only influence the larvicidal activities strongly but also are very sensitive to the insecticidal action modes for different Lepidopteran larvicidal insects.