Synthetic Process Study Of The Key Intermediate CMB Of Azoxystrobin And The Recycling Of CMP

Azoxystrobin is currently a very versatile fungicide with highefficiency,broad-spectrum,low toxicity, environmentally friendly,etc.more and moredomestic and foreign researchers have done a lot of research on the synthesisprocess,which makes the synthesis technology more mature.However,the current yieldrelated to the synthesis of azoxystrobin is not high,and the cost is relativelyhigh.Therefore,we urgently need to explore new synthesis process of azoxystrobin.this paper has conducted a survey of the relevant literature and has carried out thefollowing research on the synthesis process of azoxystrobin.1. Formamide，dimethyl malonate and sodium methoxide for the synthesis of4,6-dihydroxypyrimidine.The synthesis process was optimized, the optimum synthesisconditions were: n(dimethyl malonate): n(formamide)=1:3.0, n(dimethyl malonate):n(sodium methoxide)=1:3.5,65℃for2h. Under the optimal process conditions, thepurity of product was99.0%,the yield was89.6%(on the basis of dimethylmalonate).And it reduced the cost.2.4,6-dihydroxypyrimidine, phosgene and TBAB(four tetrabutylammoniumbromide chloride) for the synthesis of4,6-dichloropyrimidine (DCP). Phosgene is achlorinating agent. TBAB is a catalyst. The synthetic process conditions were:100℃reaction of1h. By~1H NMR、GC-MS,the product was confirmed as the targetcompound4,6-dichloropyrimidine.Under optimal process conditions, the purity of theproduct was96.3%,the reaction yield of92.4%(based on4,6-dihydroxypyrimidine).3.(E)-2-[2-(6-chloropyrimidin-4-yloxy) phenyl]-3-methoxyacrylate (CMB) wassynthesized,and the synthetic technology was optimized from the perspective of theproduct yield. In the better experimental conditions, the purity of the product was82.3%,the yield of68.1%. LC-MS、~1H NMR、IR spectrogram confirmed that theproduct was (E)-2-[2-(6-chloropyrimidin-4-yloxy) phenyl]-3-methoxyacrylate.4.4,6-dichloropyrimidine was synthesized with the recycled4-chloro-6-methoxyprimidine（CMP）. Therefore the by-product of4-chloro-6-methoxypyrimidine wasrecycled.The reaction between Bis(trichloromethyl)Carbonate and CMP wasoptimized. In the better experimental conditions, the purity of the product was98.0%,the yield of93.2%(on the basis of CMP). It could be used directly inreaction.GC-MS、~1H NMR spectrogram confirmed that the product was 4,6-dichloropyrimidine. The reaction between phosgene and CMP was optimized. Inthe better experimental conditions, the purity of the product was98.8%,the yield of92.8%(on the basis of CMP). It could be used directly in reaction.GC-MS、~1H NMRspectrogram confirmed that the product was4,6-dichloropyrimidine.