Study On The Synthesis Of Fungicide Fenhexamid

The synthesis of Fenhexamid was studied in this paper,conditions in 5-step reaction were investigated intensively.Four intermediates had been Prepared:Ⅰ(E)-2,3-dichloro-4-(phenyldiazenyl)phenol,Ⅱ 4-amino-2,3dichlorophenol,Ⅲ 1-methylcyclohexanecarbonyl acid,Ⅳ1-methyl cyclohexane carbonyl chloride;Fenhexamid was obtained by the condensation of intermediate Ⅱ with Ⅳ.The specific synthetic route was as follows:the intermediate Ⅱ(4-amino-2,3-dichlorophenol)was obtained from 2,3-dichloro phenol by"one pot" reaction contained diazo coupling and reduction,85.1%isolated yield of desired product was achieved;The intermediate Ⅲ(1-methylcyclohexanecarbonyl acid)was obtained from 2-methyl cyclohexanol by Koch-Haff carbonylation reaction,in this step,the amount of sulfuric acid was reduced and the yield was increased.Then intermediate Ⅳl-methyl cyclohexane carbonyl chloride was obtained by acylation of the carboxylic acid;The total isolated yield was up to 70.3%.The effects of reaction temperature,reaction time,mole ratio of reactors and stir speed etc.on the experiment results were investigated.Compare to the reported synthetic process,this paper’s method had advantages of mild reaction conditions,convenient procedures,high yield,good quality of products,lower operating cost and less pollution.