Study On The Synthetic Process Of Dimoxystrobin

Pesticides are the basis of agricultural income.Strobilurins compounds are a sort of fungicide with long-term performance,broad spectrum,low toxicity and high selectivity.This fungicide has also many other unique advantages as no resistance with other fungicides,easy degradation and good permeability.These factors make it more and more popular,and make the majority of researchers focus on this fungicide.In recent years,as typical representative compound of the new fungicide,the study on dimoxystrobin is very important.The datas show that global sales in 2012 reached 350 million dollars and 700million dollars in 2014.In this paper,the main purpose is to design and optimize a new synthetic route of dimoxystrobin.On the basis of large literature,we designed a new route to synthesis the target compound and optimized the reaction process.In the paper,we designed a new synthetic route based on a large amount of literature.Dimoxystrobin was synthesized from 2-methylphenylacetonitrile through the reaction of oximation,O-methylation,hydrolysis,esterification,bromination,etherification and aminolysis.Firstly,2-methylphenylacetonitrile as raw material,potassium hydroxide as alkali,and reacted with n-butyl nitrite to give 2-methyl-α-(potassium oxime)-benzyl cyanide.Then reacted with methyl bromide to give 2-(2-methyl-phenyl)-2-methoximino acetonitrile.2-(2-methy-phenyl)-2-methoximino acetonitrile was hydrolyzed in alkaline conditions to give 2-(2-methy-phenyl)-2-methoximino acetic acid.Esterified with methanol to give(E)-2-(2-methy-phenyl)-2-methoximinoacetate.Brominated with NBS to give(E)-2-(2-bromide methyl-phenyl)-2-methoximinoacetate.Then etherified with2,5-dimethylphenol under alkaline conditions to get(E)-2-(2-[2,5-dimethylphenolmethoxy)phenyl]-2-methoximinoacetate.Finally,the target product dimoxystrobin was obtained through aminolysis reaction with methylamine alcohol solution.At the same time,each step of the synthesis route that probably met problems and side effects were discussed in detail.Under the optimized conditions,reduced the generation of nitrone.The total yield was 40.5%based on 2-methyl-benzyl cyanide and the purity was 98.7%.The process has some advantages of high yield,simple operation and high purity,and it is suitable for industrial production.The final product and intermediates were tested by TLC and high performance liqu-id chromatography.The chemical structures were characterized by ~1H NMR.