Optimization Of The Synthesis Process Of 4,4'-dihydroxybenzophenone

4,4’-Dihydroxybenzophenone(4,4’-DHBP)is an adjuvant,which is used in UV absorber,photo-initiator agent and drug intermediates.In this paper,the synthesis technology of 4,4’-DHBP is studied in detail.Initially,the synthetic route of 4,4’-DHBP is ensured by the reaction which apply phenol and 4-hydroxybenzoic acid as raw material and MSA as catalyst to directly synthesize the target product.Through plenty of experiments,the optimum reaction conditions are determined that n(phenol):n(4-hydroxybenzoic acid):n(MSA)is 1:1.9:13.5,80 ℃ for 10 h.And the yield of the reaction could achieve 65.5%and the purity of the product is more than 99.8%.The structure of the target product has been determined by proton nuclear magnetic resonance spectroscopy,infrared spectroscopy and liquid chromatography and other detection methods.The technology of column chromatography and TLC thin layer chromatography are applied to comprehensively analyze the products,of which the impurities are analyzed by the method of quantitative analysis,laying the foundation for the screening of the optimum conditions.Secondly,the reuse of waste produced during the reaction is researched and the results showed that the treated material 4-hydroxybenzoic acid and MSA catalyst can be recycled and reused,the rate of recovery is 71.1%and 91.4%respectively;the recrystallization mother liquor during the reaction can be recycled nine times,verifying the thesis of this paper that the synthesis route is low cost and environmental friendly.Finally,on the basis of the laboratory test,the synthetic process of 4,4’-DHBP is prepared in expanding production.We complete the production task of 25 kilogram-scale,confirming that this synthetic route meets the requirements of industrial production.In conclusion,this paper identifies one-step 4,4’-DHBP producing technology that is simple and convenient,moreover the catalyst is environment friendly which can be reused with low-cost.