The Multi-component One-pot Synthesis Of Pyran Derivatives

Multi-component reaction is a highly efficient and green synthesis pathway,which includes excellent synthesis efficiency,simple procedure,structural diversity,environmentally friendly,atom economy and closer to the ideal synthesis.pyranoid derivatives has been a hot research on this field.In this paper,sodium bicarbonate/phosphotungstic acid as catalyst,using three components of one-pot of reaction synthesis method compose a series of pyranoid derivatives.The main research contents of this thesis are following:In this article,inorganic base NaHC03 and heteropoly acids of phosphorustungstate as a catalyst,through a one-pot method is simple and convenient synthesis of a series of spirocyclic pyran derivatives,spiro indole-pyran derivatives,4-aryl-topiramatefuran derivatives.It has high yield,easy to operate,simple post-processing,and the mild reaction quickly.For the synthesis of pyrans an efficient,fast,environmentally friendly way,with good practical value.This paper also investigated the different catalysts,different amount of catalyst,solvent and temperature on the reaction yield and reaction time impact.Ultimately determine the optimal reaction conditions for these three different systems,access to about 90%yield.At the same time,the author also by replacing the different substrates to determine the universality of the reaction,10 kinds of spirocyclic pyran derivatives,9 kinds of spiro indole-pyran derivatives and 16 kinds of 4-aryl-pyran derivatives.The fourth chapter,inorganic alkali sodium bicarbonate as the catalyst,ethanol as solvent,under reflux conditions,puts aromatic aldehyde,malononitrile and 1,3-dicarbonyl compounds together,using three components of one-pot of reaction synthesis method to compose a series of 4-aryl-pyran Derivatives.This method has short reaction time,high yield of the synthesis,and the catalyst is easy to find and inexpensive,so this method has good prospects for industrial application.Finally,through for example,step-by-step through the reaction of the total package examine,investigate the reaction mechanism of the reaction system.