Synthesis And Structure Study Of 4-thiazolidinone Derivatives In Task-specific Ionic Liquid

With the increasingly serious environmental pollution,to find a green reaction medium for chemical is inevitable trend of development.While ionic liquids as environmentally friendly green reaction medias,in organic synthesis,show to be environment-friendly,mild reaction condition,good selectivity,high yield,postprocessing convenient,recyclable ionic liquid and catalyst,etc.They can replace the conventional organic solvents,and have been widely used in organic synthesis.The task-specific ionic liquids not only have characteristics of the traditional ionic liquids, but also because of their special functional groups,show a special or specific application.They not only can be used as solvents in organic synthesis,but also can be used as a reagent or catalyst to affect the reaction process,so in organic synthesis the task-specific ionic liquids have great potential application values.N-substituted-2-chloroamides and 4-thiazolidinone derivatives are a class of heterocyclic compounds with good biological activities,are widely used in medicine, pesticide fields.At the same time they also can be used as a class of good intermediates for organic synthesis,and thus are drawn greater attention.The thesis have studied an improved synthetic method of N-substitute-2-chloroamides and an improved method of using the task-specific ionic liquids as a reaction media and a reagent for the synthesis of 4-thiazolidinone derivatives,and also have studied 4-thiazolidinones' structures and tautomerizms.The thesis is mainly consists of four parts.The first part reviewed the characteristics of the task-specific ionic liquids and their preparations,and their applications in organic synthesis in recent years.The second part was about synthetic improvement of N-substituted-2-chloroamides.By Et₃N/CH₂Cl₂ homogeneous system,the molar ratio of amine:chloro acyl chloride was 1:1.2,under a special way to add the reagents,at room temperature quickly and easily synthesizing fifteen kinds of N-substituted-2-chloroamides.This method laid a good foundation for synthesis of 4-thiazolidinone.At the same time this method has provided a improved method of organic synthesis intermediate N-substituted-2-chloroacetamides and N-substitute-2-chloropropyl amides which have a very wide application.The third part studied a improved synthesis method of 4-thiazolidinones in the task-specific ionic liquid.Comparison of different reaction media reactions under the effect of different catalysts,which in the[emim]SCN/EA reaction system with sodium acetate as a catalyst in the reaction got the best result.In[emim]SCN/EA reaction system,using N-substituted-2-chloroamides and the task-specific ionic liquid [emim]SCN as reagents with sodium acetate as a catalyst,we synthesized seventeen kinds of 4-thiazolidinones,six of which were unknown.Comparing with the traditional method,this method had a mild reaction condition,simple operation,short time,high yield,and the task-specific ionic liquid and the catalyst can be recycled and reusability for four times,the yields were almost constant.It provided a new way of thinking for the 4-thiazolidinones' research and synthesis.The four part was about the study of the tautomerism and structure of 4-thiazolidinones.Through IR,at room temperature and variable temperature ¹H NMR and X-single crystal diffraction analysis methods and so on,we studied the tautomerism and structure of 4-thiazolidinones and confirmed the structure of the various products,and analysed its tautomerism in an effort to further rational design and control of synthetic drugs with a high activity of 4-thiazolidinones,and further exploration of such compounds in vivo with the target bio-molecules combination of lay a good foundation.