Study On The Synthesis Of Azoxystrobin

Azoxystrobin is a broad-spectrum, high efficiency, low toxicity, environmentally friendly bactericide. In recent years, azoxystrobin has been widely used around the world. There is a great market demand on azoxystrobin at home and abroad. However, the synthesis technology of azoxystrobin has been protected abroad by patent, while current the domestic process of azoxystrobin is not yet ripe with relatively high production costs. So study on the synthesis process of azoxystrobin has a very important significance to reduce the production costs. Herein, based on literature survey, the studies in this thesis are summarized as follows:1. O-hydroxyphenyl acetate was successfully synthesized with o-hydroxyphenyl acetic acid and methanol as raw materials, concentrated sulfuric acid as a catalyst.1H NMR, LC/MS and IR spectra confirmed that the product was o-hydroxyphenyl acetate. The purity of the product was 98.0%, with the yield 96.0%. The process possessed the merits of lower demanding, simple operation, little dosage of the catalyst, excessive methanol recyclable, less cost required.2.4,6-Dihydroxypyrimidine was prepared from formamide and dimethyl malonate and then converted to 4,6-dichloropyrimidine by chloridizing with phosphorus oxychloride. The 4,6-dichloropyrimidine purity reached 98.0%. The total yield of this two-step process was 81.7%, the cost of this synthetic process reduced.3. Methyl 2-(6-chloropyrimidin-4-yloxy) phenylacetate was successfully synthesized with o-hydroxyphenyl acetate and 4,6-dichloropyrimidine as raw materials.1H NMR, LC/MS and IR spectra confirmed that the product was methyl 2-(6-chloropyrimidin-4-yloxy) phenylacetate. The product purity was above 96.0%, the yield was 92.6%.4. Methyl 2-[6-(2-cyanophenoxy) pyrimidin-4-yloxy] phenylacetate was successfully synthesized from methyl 2-(6-chloropyrimidin-4-yloxy) phenylacetate and 2-cyanophenol, the synthesis process was influenced by potassium carbonate and 1,4-diazabicyclo[2.2.2]octane.1H NMR, LC/MS and IR spectra confirmed the product was methyl 2-[6-(2-cyanophenoxy) pyrimidin-4-yloxy] phenylacetate. The product purity was above 94.0%, the yield reached 91.0%.5. Methyl 2-[6-(2-cyanophenoxy) pyrimidin-4-yloxy] phenylacetate took formylation reaction under the influence of trimethylorthoformate, titanium tetrachloride and triethylamine, the reaction products first suffered after-treatment, then reacted with dimethyl sulfate, then azoxystrobin was synthesized.1H NMR, LC/MS and IR confirmed that the product was azoxystrobin. The purity can reach 95.0% after recrystallization of the crude product, and the average yield was 62.6% at this moment. The total yield of this four-step process with o-hydroxyphenyl acetic acid as raw material for synthesis of azoxystrobin can reach 50.6%, the azoxystrobin process cost reduced.