Process Optimization On The Synthesis Of Fungicide Azoxystrobin

Azoxystrobin is a new agricultural fungicide which is used in a large scale at present. It contains the structure of β-methoxy acrylate which has bactericidal activity. Azoxystrobin is widely used because of its broad-spectrum and high efficiency of fungicidal activity. In this thesis, we studied the synthesis and process optimization of Azoxystrobin on the basis of comprehensive inspection of the literatures. Using 2-hydroxyphenylacetic acid as a starting material, Azoxystrobin was prepared through the successive reactions of esterification, methoxymethlenation, ester exchanging, and twice Ullmann condensation. Each step was systematically optimized including the ratios between the substrates, temperature, catalyst, and reaction time etc. Thus an optimized synthetic routine and reaction conditions were achieved. This dissertation includes the following four parts:1. In the first chapter, the properties, the historical development, and the current research development of Azoxystrobin were comprehensively summarized. Based on the main synthetic routines of Azoxystrobin, the designing ideas for this thesis were discussed.2. In the second chapter, the optimized process conditions for the synthesis of benzo-furan-2(3H)-one and 3-(a-methoxy)methylene benzofurans-2-(3H)-one were achieved, respectively.3. In the third chapter, two methods, namely fractional step and "one-pot" methods, were adopted to synthesize (E)-2-[2-(6-chloropyrimidin-4-yloxy) phenyl]-3-methoxyacrylate. The optimized conditions as well as the advantages and disadvantages of the two synthetic methods were discussed and compared with each other.4. In the fourth chapter, we finally synthesized the target product Azoxystrobin on the basis of the optimization of efficient catalysts.