Synthesis Of Phenythio Aryl Alkynes And New Nitrogen Heterocyclic Compounds

It’s reported in a large number of literatures that aryl alkynyl thioethers can be used in the field of organic synthesis as important synthetic intermediates due to an unsaturated acetylene bond, a sulfur atom of high chemical activity and a conjugated structure of rich electron, so they can be used as synthesis of a variety of aromatic compounds containing sulfur atom. Furthermore, aryl alkynyl thio ethers possess unique optical activities. And they are so valuable and prospective in the study and application of the optical material. But aryl alkynyl thio ethers’s the application of organic synthesis, material and self-assembly aspects largely depend on 1,2,3-triazoles that could be synthesized through cycloaddition reaction between these thio ethers and azides.1,2,3-triazoles that can be achieved via cycloaddition reaction are very stable in metabolic transformation, oxidation reduction, even in acidic or alkali conditions. As a result, these nitrogen heterocyclic compounds could be used for drug discovery, pesticide production, synthesis of natural-derived product, coupling of biological molecule and functional polymer material modification.This paper focus on synthetic methodology of aryl alkynyl thio ethers and the synthesis of 1,2,3-triazoles. We use inexpensive aryl acetophenones as starting materials via bromination to obtainα-bromo-aryl acetophenones, then phenylthio methyl phenyl ketones were got by dealing with thiophenol. Based on the research results of our laboratory in the foretime, we made the phenylthio methyl phenyl ketones to fix on the enol triflate by using LiHMDS and ClPO(OEt)2 successively, then acquired phenylthio aryl ethyne series by the way of elimination reaction. The optimum conditions of synthetic phenylthio aryl ethynes were established through series of contrast tests.The“one-pot”method not only has features in efficiency, highly selective, small environment pressure, simple operation and extensive application scope, but also can be used to synthesize various substituent aryl alkynyl thioethers. So the new method is a new way of the synthesis of aryl alkynyl thioethers.Then phenylthio aryl ethynes were used as the starting material, reacted with benzyl azide, synthesized a series of substituted 1,2,3-triazoles which contain thiophenyl group through Sharpless reaction. The optimal conditions of 1,3-dipolar cycloaddition between phenylthio aryl ethynes and benzyl azide were established via a series of comparative tests. The method not only has features in facile reaction conditions, raw material acquiring easily and insensitivity to water and oxygen, but also it is of ideal yield, highly selective, handled easily and good versatile. The reaction systems of synthesis of 1,2,3-triazoles are broadened and this provides a new way of synthesize 1,2,3-triazoles substituted by heteroatoms.All of intermediates and target compounds in this paper have been determinated by MS, 1H NMR, 13C NMR.