Synthesis And Characterization Of Octocrilene Derivatives UV Absorbents

Octocrylene as a kind of UV absorbers and the progress of its development so far were described in this paper.For Octocrylene with the good protection from the UV irradiating,the Octocrylene derivatives 2-cyano-3,3-diphenyl acrylates and 2-cyano-3,3-(4,4-dichloro) diphenyl acrylates were synthesed.Firstly, concentrated sulfuric acid as catalyst, the intermediates of cyanoacetate(compound Ⅰ1~2) were prepared by the reaction of cyanoacetic acid with alcohol.Then the target compounds Ⅱ1~2 and Ⅲ1~2 were obtainted through the Knoevengal reaction with a catalyst NH4OAc/HOAc.finally, the target compounds Ⅱ3~6 and Ⅲ3~6 were synthesized by transesterification.The synthesized Octocrylene derivatives are tested in this study.The UV absorption spectra of 2-cyano-3,3-diphenyl acrylates and 2-cyano-3,3-(4,4-dichloro) diphenyl acrylates were obtained by UV spectrophotometer,and thermal stability of the target compounds was tested by Thermo Gravimetric Analyzer. The result shows that 2-cyano-3,3(4,4-dichloro) diphenyl acrylates are better than 2-cyano-3,3-diphenyl acrylates about the ultraviolet absorption properties and thermal stability. In short, the ultraviolet absorption properties and thermal stability of the compounds can be improved by chlorine atom on the benzene ring.Moreover,the mechanism was discussed about the transesterification reaction and Knoevengal condensation.The compounds synthesized were confirmed by 1H NMR,IR.