Synthesis And Characterization Of Arylpyrazole Derivatives

Pyrazole derivatives play an important role in nowdays pesticide development,fipronil is a important kind of aryl-pyrazole insecticide, which is an GABA-chloridechannel inhibitor. Fipronil is toxic to bees and other aquatic life, and unfriendly toenvironment, this restricts the drugs widespread using. In order to reducing the sideeffects of fipronil and getting better insecticides, this paper designed and synthesizeda series of eighteen new aryl pyrazole Derivatives, And its structure wascharacterized.1, amino benzophenone derivatives were synthesized from substituted anilinesand o-fluorobenzoyl chloride,and the derivatives condensated with hydrazinehydrate. Diazonium salts were formed by diazotization of the aromatic amines.Thesalts reacted with2,3-dicyano propionate getting3,5-substituted-1-[2,4-substituted-(1-alkyl indazol)-phenyl]–pyrazoles,or the salts were reduced tohydrazines, and reacted with1,3-diones, or3-ethoxy-2-cyano ethyl acrylatesgiving containing indazole-ring aryl pyrazole derivatives. All of the aryl pyrazolederivatives reacted with NBS lastly.2, The above-described benzophenone derivatives reacted with acetone oximesgetting aromatic amines,which contained1,2-isoxazole rings. Aryl pyrazolederivatives containing1,2-isoxazole ring were synthesized by using theabove-described methods. The pyrazole derivatives have not been reported. Becausearomatic amine containing weak electron-withdrawing group was not soluble inwater, we used glacial acetic acid instead of water as the solvent.This methodimproved the reaction efficiency. The activities of title compounds were predicted byrelated softwares.