| The food crisis has always been a global hot topic.According to reports,the number of hungry people in the world is expected to increase by 120 million this year.In the future,as the global population continues to increase,in order to meet the basic living conditions of mankind,it is still necessary to reduce pests and diseases through the use of large amounts of pesticides.To ensure the balance of supply and demand for global food production,although there are many types of pesticides,organic synthetic pesticides are currently the most used and most widely used category.Nowadays,high activity,high selectivity,environmental friendliness and low toxicity are the subjects of the creation and development of new pesticides.Isoxazoline is a new type of new type of pesticide that acts on specific sites of ionotropic gamma-aminobutyric acid(GABA)receptors.Insecticides,which have no obvious cross-resistance with existing insecticides,have a broad insecticidal spectrum,and are safe for mammals.At present,more and more pesticide developers have paid attention.This thesis is based on the previous research results of the research groupand related patents.On the one hand,the compound I and the known compound II with higher activity are selected as the lead compounds.On the other hand,the basic active skeleton of the isoxazoline remains unchanged and the tail is changed.In Part C of the chain,replace the original groups with alternative small molecule functional groups.A total of36 synthetic compounds and intermediates were designed,including 23 new compounds,1 known compounds,and 12 intermediates.The structures of the target compounds are all confirmed by ~1H NMR and MS.The insecticidal activity of most of the compounds was tested and the possible structure-activity relationship was discussed,which laid the foundation for the next research of the research team.The compounds in this thesis are divided into three parts according to their structural characteristics for design,synthesis and biological activity testing.The activity data of isoxazoline compounds(Ⅰ)show that the insecticidal activity of all target compounds is better than the commercial varieties of chlorantraniliprole,but slightly lower than its lead compounds,including cyclopropyl acetyl chloride and methoxy acetyl chloride The substituted compounds have excellent insecticidal activity against Plutella xylostella,which can be further studied.For isoxazoline compounds(II),the insecticidal activity of these compounds is also significantly better than that of tetraclofenac,and the acetyl-substituted compound II-2 has the highest activity.The biological activity of the oxazolinecompound(Ⅲ)is not very satisfactory,indicating that the activity of the isoxazoline compound is greatly affected by the structure of its tail chain,and it shouldnot be modified too much,but should be retained or modified in a small range. |
