Study On The Synthesis Technology Of Pymetrozine And The Synthesis Of Aryl-isoxazole Triazone

Pymetrozine is a new heterocycle pesticides preventing and cure aphids and white fillie s ,which has many characteristics such as high performance,low toxicity,high selectivity and environmentally friendly. Because of its unique mode of action, which become the best agent against aphids. With the increasing emphasis on environmental protection throughout the world, pymetrozine as an excellent new pesticide has registered in many countries and regions, and to be listed,Its research and development has good prospects, will bring enormous social and economic benefits.In the reported methods of synthesis pymetrozine, the product yield is low, there is limitation in the technics, so it is difficult for the industrial product. In this article,we research each reaction in the process of synthesis pymetrozine detailly, on the basis of this study we developed new methods to synthesize some intermedia tes, to made the synthesis of pymetrozine more simple, safe,and environmentally fri endly; optimized technologci al conditions, made the product yield of pymetrozine higher than 50%, to promote it industryial produce and use.1.Compared the reported synthesize methods of acetyl hydrazine, acetyl hydrazine was synthesized by direct reaction of ethyl acetate and hydrazine hydrate, Through the study of factors such as reaction temperature,reactant ratio and feed sequence, improved the synthesis methods, optimized the technologcial conditions, made the product yield of acetyl hydrazine higher than 50%, greatly shorten the reaction time, improve the efficiency of the reactor.2.The synthesis of intermediate oxadiazone is the key in the synthesis of pym etrozine,in the process of synthesize oxadiazone with traditional method used highly toxic substance-phosgene, because of the strong killing capacity, greatly restricted the product and use of pymetrozine. This project used solid phosgene substitute phosgene to synthesize oxadiazole ketone, research the factors such as solvent, reaction temperature, feed ratio and feed sequence , under the optimum reaction condition the yield of oxadiazole ketone higher than 82%,but with this method the raw material conversion low, use excessive solvent and product purity low. On the basis study above, developed Two-phase method to synthesize oxadiazone, with this method the product purity high, the product handling simple, through the study of technologcial conditions of this method , made the yield of oxadiazole ketone higher than 85%.3.The synthesis of intermediate acetonyloxadiazole ketone is one impormant step in the synthesis of pymetrozine, which was synthesized buy sodium hydride and sodium methoxide in the traditional synthesis methods, through the study of technologcial conditions of each method, under the optimum reaction condition the product yield of sodium hydride method higher than 88%, the product yield of sodium methoxide method higher than 78%.In the research of synthiese acetonyloxadiazole ketone buy sodium hydride,discovered that the purity of sodium hydride must higher than 90%, otherwise, product handling trouble, the purity and yield of which is low, but if high-purity sodium hydride was used , the price of which was expensive, made the product cost too high. In the research of synthiese acetonyloxadiazole ketone buy sodium methoxide, discovered that the reaction must under the two systems, otherwise, too many adverse reaction, large consumption of raw materials, but under the two systems, the conversion of raw materials and the product yield is low. On the basis study above, developed a new method to synthesize acetonyloxadiazole ketone buy weak base, with this method the product cost low, the product handling simple, through the study of technologcial conditions of this method , made the yield of acetony loxadiazole ketone higher than 84%.4.The synthesis of intermediate aminotriazone is one impormant step in the synthesis of pymetrozine, which was synthesized buy hydrolysis with weak acid, through the study of technologcial conditions, under the optimum reaction condition the product yield of aminotriazone higher than 88%, but with this method, waste excessive raw materials, use excessive water and high energy consumption, made the product cost high. On the basis study above, developed a new method to synthesize aminotriazone buy hydrolysis with strong acid and methanol as solvent, with this method product cost low, the product handling simple, through the study of technologcial conditions of this method , made the yield of aminotriazone higher than 92 %.5.Through molecular design and synthesis lead compounds, and then optimize the structure has become an important way for new drug development. Triazone derivatives were a class of potentially biologically active heterocyclic compounds, pymetrozine with insecticidal activity is a typical compound of triazone. With pymetrozine as lead compounds, lead aryl-isoxazole ring substituted the pyridine ring in pymetrozine, designed and synthesized a new compound.