Study On Green Synthesis Of Cyclohexanedione-Type Herbicide

The function and development of pesticide were reviewed in this peaper.The history and present situation of herbicide were summarized, then sulcotrione and mesotrione which were cyclohexanedione-type herbicides were summarized about their synthetic routes,physical and chemical property,action mechanics and toxicity etc with more than ninety references.Based on references,the synthetic routes of sulcotrione and mesotrione were picked out and optimized.3-chloro-4-methyl-methylsulfonylbenzene, an intermediate of sulcotrione,was synthesized using 4-methylbenzenesulfonyl chloride as a primary material,followed by chlorination with chlorine,reduction with sodium carbonate and sodium sulfite,alkylation with sodium chloroacetate.3-nitro-4-methyl-methylsulfonylbenzene, an intermediate of mesotrione,also was synthesized using 4-methylbenzenesulfonyl chloride as a primary material,but firstly by reduction and alkylation,then nitration with mixed acid.3-chloro-4-methyl-methylsulfonylbenzene and 3-nitro-4-methyl-methylsulfonylbenzene were oxidated by air or nitric acid to prepare 2-chloro-4-(methylsulfonyl)benzoic acid and 2-nitro-4-(methylsulfonyl)benzoic acid which were acylated with BTC to obtain 2-chloro-4-(methylsulfonyl)benzoyl chloride and 2-nitro-4-(methylsulfonyl)benzoyl chloride.After that,the chloride reacted with 1,3-cyclohexanedione in the presence of potassium carbonate as acid acceptor and acetone cyanohydrin as rearrangement catalyst to carry out the condensation and rearrangement reactions to obtain sulcotrione and mesotrione at last.Through the experimentation,an optimum synthetic route of sulcotrione and mesotrione was chosen,and some.steps were optimized by green method.The route was suitable for industrial production.