Synthesis Of Pyrane Derivatives Via Multi-Component Reaction Catalyzed By Alkaline Ionic Liquid

Because of some unique properties, multi-component reactions were widely used in organic synthesis. Multi-component reactions could improve the efficiency of synthesis, simplify operation, friendly to environment and high atom economy, closer to the ideal synthesis. The compounds and drug intermediates with structural diversity and complexity could be synthetized by Multi-component reactions and conformed to the trend of the development of the modern chemistry. Pyran derivatives often have physiological and pharmacological activities, researchers often chose malononitrile as the reaction substrate synthetized a series of pyran derivatives. In recent years, some compounds such as ethyl cyanoacetate、cyanoacetamide、phenylsulphonylacetonitrile were found which can be used to replace the malononitrile in multi-component reactions, and some special functional groups were introduced accordingly. This paper presented methods of in the present of ionic liquid, aldehyde、phenylsulphonylacetonitrile reacted with β-naphthol or dimetone to get the related pyran derivatives. The following is the structure of the paper.The first part briefly explained the definition, types and properties of ionic liquids and summarized the application of ionic liquids in organic synthesis reactions, drew out the research direction of this paper.The second part studied an improved synthetic of unsaturated arylsulfones by the three-component reaction of aromatic aldehydes, acetonitrile and benzene sulfonic acid sodium. It was catalyzed by basic ionic liquid [Bmim] OH in ethanol under conventional heating condition. Besides, the Ionic liquid was successively recovered and reused for five times without remarkable loss in the catalytic activity.The third part was about the three-component reaction of aromatic aldehydes, phenylsulphonylacetonitrile and dimetone in the present of basic ionic liquid HEAA under heating conditions to get a series of pyran derivatives. This method has some advantages such as short reacton times, high yields; simple operation and the catalyst also could be reused.The forth part was about three-component reaction of aromatic aldehydes, phenylsulphonylacetonitrile and p-naphthyl hydroxide. This method took HEAA as catalyst in water under conventional heating conditions. In the last, we got a series of pyran derivatives, so the method could be used for many kinds of reaction substrates. In addition, this method was a kind of green environmental protection technology with little pollution to the environment.The fifth part which was based on the results of experiments summarized the dissertation and anticipated the future research works.