Study On The Synthesis And Process Of Fludioxonil

Fludioxonil is a novel pyrroles fungicide. This paper aims to develop an appropriate route of Fludioxonil on industrial scale. Beginning with O-cresol, a-cyano-3-(2,2-difluoro-1,-3-ben-zodioxol-4-yl)-2-propenamide was produced via formaldehyde, Dakin oxidazation, esterfication, chlorination, fluoronation, hydrolysis and Knoevenagel condensation reaction; (4-Methylphenylsulfonyl)methyl isocyanide was synthesized by dehydration of N-(p-toluene-sulfony-lmethyl) formamide which can be prepared by sodium p-toluenesulfinate; Finally, Fludioxonil was synthesized by the reaction of a-cyano-3-(2,2-difluoro-1,3-benzodioxol-4-yl)-2-propenamide and N-(p-toluenesulfonyl-methyl) formamide. The total yield was 14.4%, and the purity of the target product was 99.9%. The yield of the process of chlorination was improved through distillation and recycling intermediates; the purity of the product of fluorination was improved largely via using KF as fluorination agent. Put forward the method that preparing for a-cyano-3-(2,2-difluoro-1,3-benzodioxol-4-yl)-2-propenamide by using ammonium acetate as the catalyst and the yield was increased up to 74.8%. The chemical structures of reaction products were characterized by MS,1HNMR. The reaction mechanism of each reaction and the major influencing factors were discussed. The process was low cost, simple and suitable for industry.