Study On Synthesis Of UV Cationic Photoinitiator Sulfonium Salts

A large number of benzothiophene derivatives and aryl sulfide compounds have the drug activity and physiological activity, and also have a wide range of applications in the dyes, new materials and other fields, so they are greatly concerned by the majority of chemistry researchers. They are developing constantly a very promising research area. Sulfonium salts can be used as cationic photoinitiators, phase transfer catalysts, light-induced acid, cationic fluorescent probes and biological sensors, etc. The literatures on the synthesis of sulfonium salts and cationic photoinitiators curing to resins have been largely reported. They have became the research focus.Based on the analysis and summary the literatures, my works were carried out including the following aspects:1. In the microwave irradiation conditions, the Friedel-Crafts reaction of benzothiophene with oxalyl chloride in the presence of aluminum chloride catalyst were carried on. The different reaction condition influence on the reaction were discussed. The structures of products were characterized by 1H NMR and 13C NMR. The reaction mechanism was speculated.2.1-Phenylbenzothiophenium triflate was readily prepared by the reaction of the corresponding benzothiophene with diphenyliodonium triflate in the presence of a catalytic amount of copper(Ⅱ) acetate. After the ring of 1-Phenylbenzothiophenium triflate was opened in the alkali methanol or ethanol sodium. (2-ethynylphenyl)(phenyl)sulfane could be obtained. (2-(2-phenylethynyl)phenyl)(phenyl)sulfane was gained by the reaction of (2-ethynylphenyl)(phenyl)sulfane with iodine benzene in the presence of palladium chloride catalyst. The reaction conditions of temperature and amount of catalyst were optimized.2-(ethylthio) benzothiazole could be prepared by the reaction of 2-thiolbenzothiazole with iodine ethane. Its reaction conditions of temperature and reaction time were optimized.3. The triarylsulfonium could be prepared with (2-ethynylphenyl) (phenyl)sulfane. The different 1,2-dichloroethane, dichloromethane, acetonitrile reagent influence on products were investigated. The reaction of 3,3'-dibenzothiopheneenthydione, benzothiazole,3-benzoylthiophene, 3-butyl benzothiophenacrylate,2-(ethylthio)benzothiazole,2-(phenylthio) benzothiazole compounds with diphenyliodonium triflate in the presence of copper acetate was respectively investigated.4. The curing performance of 1-phenylbenzothiophene salt and benzoyl benzothiophene as a photoinitiator was tested.