Design,Synthesis And Insecticidal Activity Study Of New Pesticide Molecules

Aphids are one of the most destructive pests in the world and cause great economic loss to our country every year.However,the problem of chemical pesticides used to control aphids has become very prominent.Therefore,we try to study and develop new aphid active pesticides.Based on the studies of aphids control,we designed and synthesized three series of derivatives with the natural plant quinazoline alkaloid luotonin A,Triflumezopyrim and Flupyradifurone.And some of the derivatives were tested for the eradication of aphids and brown planthopper.The full text consists of four parts:Part I: We detailedly summarized the harm of aphids,the problem of chemical pesticides and introduced three new green pesticide molecules:luotonin A,Triflumezopyrim and Flupyradifurone.Part II: Design,synthesis and insecticidal activity studies of natural luotonin A.In this experiment,we used luotonin A as lead compound and synthesized luotonin A and its derivatives by the method of Zhou.At the same time,we synthesized luotonin F by one step reaction.And the toxicity test of luotonin A was carried out on alfalfa aphids,pecans,locust aphids and peach aphids.The results showed that luotonin A has excellent toxicity activity against four aphids.Even at the concentration of 5 mg/L,it could reach more than 50% of the lethality.Part III: Design,synthesis and insecticidal activity studies of Triflumezoprim as a new mesoionic pesticide.Among the sucking pests,the rice planthoppers are one of the most difficult to control apart from aphids.However,the recently reported mesoionic insecticide Triflumezopyrim and Dicloromezotiaz have attracted people's attention because of their high toxicity to brown planthoppers.Therefore,we used Triflumezopyrim and Dicloromezotiaz as lead compounds and synthesized two series of mesoionic derivatives.And the toxicity of target compounds was tested.The results showed that the compounds 24a-24 n did not show expected toxicity to brown planthopper,but the compound 25 a demonstrated the similar toxicity to brown planthopper compared with the lead compound.Part IV: Design,synthesis and insecticidal activity studies of Flupyradifurone as a new butenolide pesticide.Bee toxicity has always been a difficult problem for pesticide research.The recently reported butenolide insecticide Flupyradifurone by Bayer company,not only exhibited good toxic activity against sucking pests,but also safe for bees.Therefore,we used Flupyradifurone as lead compound and synthesized a series of butenolide derivatives and all derivatives were tested for insecticidal activity.The results showed that Flupyradifurone and derivatives did not demonstrate excellent activity on the control of brown planthopper,but the Flupyradifurone showed good killing activity against alfalfas and pecan aphids.Nonetheless,the derivatives did not show superior activity to the lead compound.