Research On Green Synthesis Process Of Strobilurin Fungicide Pyraclostrobin

Strobilurins fungicide is a sort of fungicide with high efficiency,low toxicity,broad-spectrum,and it attracts many well-known pesticide enterprises to develop the new fungicide varieties for its unique mechanism.At present,Strobilurins fungicide occupied more than 90% of the fungicide market.Pyraclostrobin is an important fungicide of BASF,and it has the highest biological activity in Strobilurins fungicide.Besides being environmentally friendly,it has the function of plant health protection.Through a series of studies,we effectively improved the reported process of Pyraclostrobin.With 4-chlorophenylhydrazine hydrochloride as starting material,the intermediate 1-(4-chlorophenyl)-3-1H-pyrazole was synthesized via cyclization and oxidation in practical “one pot” process,following condensation with 1-(bromomethyl)-2-nitrobenzene to afford 1-(4-chlorophenyl)-3-((2-nitrobenzyl)oxy)-1H-pyrazole,and total yield of the first three steps is 76%.The target product was obtained by catalytic hydrogenation with Pt/C,N-acylation and O-methylation.In this paper,the bromination reaction rate of 2-nitrotoluene was increased by the addition of catalyst,and it avoid a lot of bromine accumulation.The selectivity of hydrogenation was improved by the additive,and the post-treatment was also simplified.Comparing with the existing literature,the process has the advantage of wider diversity of raw material,simple operation,environmentally friendly,and is suitable for industrial manufacture.