Study On The Synthesis Of Pyrazole Carboxylic Acid And Its Analogues

The pyrazole amide insecticides were introduced by summarizing a mass of literatures in this paper.And the mechanism,toxicity and synthesis routes of tolfenpyrad and tebufenpyrad were reviewed in detail.The optimum synthesis route of tolfenpyrad and tebufenpyrad has been gotten through comparing the advantages and disadvantages of different routes.The synthesis technology was improved by a series of experiments.Using diethyl oxalate and butanone as starting materials,the intermediate pyrazole carboxylic acid was prepared by means of Claisen reaction,cyclization,methane chloride methylation,sulfuryl chloride chlorination.Then the mixed acid anhydride is produced by reacting between pyrazole carboxylic acid with 4-tosyl chloride.Finally,tolfenpyrad and tebufenpyrad were synthesized by reaction of mixed acid anhydride with 4-(4-methyl phenoxy)benzylamine and tert-butyl benzyl amine.And the optimum technological conditions,such as reactant proportion,catalyst choosing,reacting temperature,reacting time,etc.,have been obtained.At the same time,eight pyrazole carboxylic acid analogues were designed,prepared and tested for biological activity.In this paper,the structures and purity of products were confirmed by H-NMR,MS,FT-IR,HPLC and melting point,etc.