Substituted Vinyl Benzimidazole Synthesis And Application Of Iodized Salt

By the condensation reaction of 1,2,3-trimethyl benzimidazolium iodide with aromatic aldehyde under organic base, five kinds of styryl dyes have been synthesized. This series of styryl dyes haven't been reported before. All of them have been characterized by UV,EA,IR,1HNMR.The mechanism of reaction was studied. It was found that the reaction could be only catalyzed by strong organic base such as piperidine. The mechanism of reaction is presented in this paper. The UV spectrum of 1,3-dimethyl-2-(p-chloro styryl) benzimidazolium iodide has been studied in this paper. It shows the dye is stable in the methnol. Itsλmax won't be changed with the alterability of the concentration and the pH. With the addition of surfactant, the λmax of 1,3-dimethyl-2-(p-chloro styryl) benzimidazolium iodide won't be changed too. The FS spectrum of the dyes has been studied. The effect of the solution's pH on the fluorescence intensity of 1,3-dimethyl-2-(p-hydroxy styryl) benzimidazolium iodide has been discussed too.A novel convenient synthesis of α,β- unsaturated ketones through the 2-methyl carbon's nucleophility of 1,2,3-trimethyl benzimidazolium iodide and 2-carbon's electrophility of substituted ethenyl benzimidazolium iodide is provided. This method has not been reported before. Eleven kinds of α,β- unsaturated ketones have been prepared by this novel synthesis. All of them are trans configuration. The major advantages of the method described here are the readily availability of the substrates, simplicity of isolation of the products and mild reaction conditions. The byproduct can be reused too. The mechanism for this reaction of substituted ethenyl benzimidazolium iodide with Grinard reagents is discussed in this paper. Hu,zhi-biao(organic chemistry)Directed by Wang, lan-ying...