The Study On The Synthesis And Biological Activities Of New Insect Chitin Inhibitors Containing 5-aminothiazole Ring

In the next ten years,chemical pesticides is indispensable in the insect control.Exploring and finding a pesticide highly active and safe is still a hot spot for pesticide creation.Benzoylurea insecticides is chitin synthesis of high-performance inhibitors with high environmental safety,low concentration of use and fast degradation,known as the "21st century pesticides".Fluorine has a special physical and chemical properties,such as small radius(similar to H),strong electronegativity,etc..The introduction of fluorine atoms or fluorine-containing groups in the active molecules can change the properties of the lipophilicity and stability of the active molecules,so as to further change their bio-physiological activity;2-aminothiazole compounds with a broad spectrum of biological activity is an important branch of thiazole derivatives,and plays a very important role in the field of pesticides and medicine.From the structural analysis,5-aminothiazole and 2-aminothiazole are identical isomers;From the perspective of bio-electronic isometric analysis,they are a pair of classic bio-electronic isotype and similar in affecting some important parameters of their bio-physiological activities,such as electrical parameters,stereo parameters and hydrophobic parameters.They are likely to have similarity in biopharmaceutical activity.In this study,through bio-isosteres and active sub-structure splicing method,a new 5-aminothiazole ring nucleobenzoylurea insect chitin inhibitor was synthesized by replacing the arylamino fragment with 5-aminothiazole fragment.On the basis of previous research work,with the discovery of the highly active compounds A7 and A10 as the lead,fixed molecular basic skeleton and change one variable at a time.To investigate the effect of the introduction of fluorine atoms or fluorine-containing groups on the activity of the lead compounds,the effects of the position and species change of the substituents on the thiazole ring and benzene ring on the insecticidal activity were studied.A total of 42 novel chitin inhibitors containing 5-aminothiazole ring nucleobenzoic acid urea insects were designed and synthesized.The structures were confirmed by 1H NMR and 13C NMR.And all the target compounds were tested for insecticidal activity.The test structure shows that:The lethal rate of the compounds ?11-?15,?15,?17,?2,?9,and ?10 was 100%for the armyworm at a concentration of 600 ppm;?7 and ?10 at 10 ppm had a 100%lethality to mosquito larvae;?13,?15,?2,?9,?10 and ?20 were 100%at a concentration of 600 ppm for Helicoverpa armigera;?13,?15,?16,?2,?9,?10 and ?20 in the concentration of 600ppm on killing the corn borer mortality's rate is 100%.This study found that some of the highly active compounds.And the accumulate data about relevant structural activity can be used for the follow-up research group to provide reference.In addition,it was not obvious that finding the kind of group to the insecticidal activity of the compound by leading fluorine atoms or fluorine-containing groups into the structure of the compounds.In this paper,the key intermediates 2,4-disubstituted 5-aminothiazole were synthesized by reference to the Ugi-four-component reaction reported by Thompson et al.Twenty-one such intermediates that have not been reported in the literature has been synthesized,expanding the species of the reaction acid components of the Ugi-four component.Through exploring,the kind of reaction of the acid components,as ortho substituents,can not be completed by the reaction conditions of the Ugi-four component,which has been solved.And the reason why the kind of acid component is difficult to react from the point of view of the mechanism has been described.