Study On The Synthesis Techniques Of Fungicide Azoxystrobin

Azoxystrobin is a β-methoxy acrylic natural bactericide and isolated from mushroom.with the features such as high efficiency, broad spectrum, protection, treatment,and low toxicity.Azoxystrobin is another new agricultural bactericide with great development potential and market vitality after the three triazole fungicide.Which is synthesized through7steps of reaction and takes O-chloro phenylacetic acid as the starting material in this paper.the product content is more than97%, yield is more than53.5%(by o-chlorophenylacetic meter).Products of every step are identified by NMR, and the process is optimized in this paper. In the first step, o-hydroxyphenylacetic acid is prepared with8-hydroxyquinoline copper as catalyst at160℃by o-chlorophenylacetic acid hydrolysis and the product isn’t separation and used directly for next step.In the second step, Benzofuran-2(3H)-one was synthesized from o-hydroxyphenylacetic acid with p-toluene sulfonic as catalysts. In the third step,(E)-3-(methoxymethylene)benzofuran-2(3H)-one was synthesized with anhydrous aluminium chloride as catalys instead of anhydride compounds.The better ratio of chemical compound is obtained through the single factor experiment.The yield is92.1%when the ratio of benzofuran-2(3H)-one to trimethyl orthoformate to nhydrous aluminum chloride equals to1.0:2.0:0.015.This method not only has good atom economy, but also could obtain the content of more than94.4%. The better condition was obtained through the single factor experiment in the fourth reaction.91.0%yield is obtained when the ratio of (E)-3-(methoxymethylene)benzofuran-2(3H)-one to sodium methoxide to methanol equals tol.00:1.06:14,reaction temperature is-5℃.The product that not to be separated and used in the next reaction.The better reaction condition was obtained through the single factor experiment in the fifth reaction.The results is better when the ratio of methyl2-(2-hydroxyphenyl)-3,3-dimethoxypropanoate to4,6-dichloropyrimidine equals to1:1.15,reaction temperature is70～75℃. The better reaction condition was obtained through the single factor experiment in the sixth reaction.The results is better when the ratio of methyl2-(2-(6-chloropyrimidin-4yloxy)phenyl)-3,3-dimethoxypro-panoate to Methanesulfonic acid equals tol.0:0.15,reaction temperature is95～100℃.In the seventh reaction, the results is better when the ratio of (E)-methyl-2-(2-(6-chloropyrimidin-4-yloxy)phenyl)-3-methoxyacrylate to2-hydroxyben-zonitrile to sodium carbonate equals to1.0:1.1.1.0,reaction temperature is100℃,the solvent is toluene.From creamy-white to pale yellow solid can be obtained by decolorization with activated carbon and recrystallization in methanol,its content is more than97%.