Research On Synthesis Of Sodium 3,5,6-Trichloropyridin-2-ol

Sodium 3,5,6-trichloropyridin-2-ol is an important chemical material, chelating floating agent of choiceness performance, main intermediate for synthesizing O-O-diethyl-O-3,5,6-trich- loro-2-pyridyl phosphorothioate.The method for producing trichloropyridinol sodium include pyridine route, acrylic acid way, benzene trichloroacetate and trichloroacetyl chloride way. The thesis chose the method of trichloroacetyl chloride as the way to synthesize trichloropyridinol sodium.The process which to synthesize trichloropyridinol sodium with trichloroacteyl chloride and acrylonitrile including addition, cyclization and aromatization. Among the three steps, addition reaction is the crucial step and decides the speed of the reaction. The factors influencing the yield such as reaction temperature, reaction time, the quantity of catalyst, the ratio of raw, the quantity of solvent, ect, were studied. The optimal reaction condition was determined and confirmed by repeat experiment. At last, thesis brought forward optional control parameters of technology. The reaction temperature was 137℃, reaction time was 6.5h, n(trichloacteyl chloride):n(acrylonitrile) was 1:1.34, m(Cu) was 0.16g and m(CuCl) was 0.64g, the amount of nitrobenzene was 90ml.The production is obtained under optimal reaction condition and the average yield is 78.5%. The structure of sodium 3,5,6-trichloropyridin-2-ol is identified by infrared spectra(IR). The content of sodium 3,5,6-trichloropyridin-2-ol determined by the High Performance Liquid Chromatogram method is 90%.Catalyst were prepared by supporting CuCl on silica gel(SiO2)and activated carbon(C), and the effects of the both catalyst on the synthesis of 3,5,6-trichloropyridin-2-ol sodium were studied. The results show that, the catalyst of supporting CuCl on activated carbon(C)was better for this performance. The catalyst were characterized by XRD, and activity evaluation was carried out.