Study On Synthesis Heterocyclic Compounds Via Multicomponent In Ionic Liquids

Ionic liquids,with their unique properties,including low volatility,high polarity,good thermal stability over a wide temperature range and selective dissolving capacity by a proper choice of cations or anions,have attracted increasing interest in the organic transformations as reactioin medium as well as catalyst.Multicomponent 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.Heteroatomic compounds is an important class of heterocycles species possessing extremely rich biological activities,which play important roles in the pharmaceuticals,agricultural chemicals and natural bioactive compounds.Therefore,efficient synthesis of heterocycle is the focus of research interests of organic chemists.With the development of modem organic synthesis,more and more new organic synthetic methodologies have been applied in the synthesis of heteroatomic and heterocyclic compounds.In this paper,with the view of green chemistry,a varity of heteroatomic compounds which posses potential biological and pharmaceutical activities were designed and synthesized using ionic liquids as green catalyst or reaction medium through multicomponent reaction.The main contents as follow:The first part reviewed the characteristics of the task-specific ionic liquids and development,and their applications in organic synthesis in recent years.The second part was about three-component condesation reaction of aromatic aldehydes,?-naphthylamine and barbituric acids in ionic liquid[bmim]BF4 under conventional heating conditions.Ionic liquid was as a reusable catalytic system for the after 5 runs and without evident loss of activity,it is a green and environmentally benign synthesis methodology for the products.All products are unknown compounds,which were characterized by IR,1H NMR and MS.The third part studied an improved synthetic method of 2'-aminobenzothiazolo-arylmethyl-2-naphthols.A series of 2'-aminobenzothiazolo-arylmethyl-2-naphthols were synthesized via three-component reaction of aromatic aldehydes,2-aminobenzothiazole and 2-naphthol using inexpensive and simple acidic ionic liquid[Hnmp]HSO4 as catalyst under solvent-free conventional heating conditions.The different ionic liquids and the reuse of the ionic liquid[Hnmp]HSO4 were discussed.The four part was about three-component reaction of aromatic aldehydes,malononitrile or ethyl cyanoacetate,and 2-hydroxy-1,4-naphthoquinone to produce benzo[g]chromene derivatives in the presence of ionic liquid[bmim]OH as catalyst in ethanol at room temperature.The method has several advantages such as simple operational procedure,mild reaction condition,high yields and the catalyst could be reused,which is much valuable in industrial applications.