Study On The Synthesis Of Heterocyclic Compounds Under Ultrasound Irradiation

The ultrasonic chemistry is a new interdisciplinary subject that is developed by penetrating acoustics and the chemical into each other. It is one of the forefront of acoustic and chemical disciplines. Ultrasonic chemistry is a subject that can improve chemical production rate mainly making use of ultrasonic accelerated chemical reaction. A great many of organic reactions can be carried out in shorter time, higher yields or milder conditions under ultrasonic irradiation. It can even set off some reactions, which can not be carried out under traditional conditions.In this dissertation, the synthetic reactions of heterocyclic compounds derivatives occurred under ultrasound irradiation and their applications in organic synthesis have been studied. The whole work is mainly composed of following five parts:In part one, the recent progresses on the synthesis of heterocyclic compounds under ultrasound irradiation home and abroad, the significance and bases of the selection of the subject, the original points and the research techniques have been reviewed.In part two, the synthesis of pyrazole and isoxazole derivatives under ultrasound irradiation has been established. The present procedure avoided the use of poisonous organic solvent during the reaction, and showed a short reaction time and good yields.In part three, a convenient approach to the synthesis of thiapyans and pyridine derivatives in ethanol under ultrasound irradiation. It is possible to apply tenets of green chemistry to the generation of interesting products using ethanol media methods that are less expensive and less toxic than those with organic solvents. Compared with traditional methods, moreover, the procedure offers several advantages including excellent yields, shorter reaction time, clean reactions, and minimal environmental effects.In part four, a facile and efficient entry into a new series of highly functionalized pyrrolo[2,3-kl]acridine-l-one derivatives under ultrasound irradiation. Particularly valuable features of this method include high yields of products, broad substrates scope and straightforward procedure.In part five, we have successfully combined the advantages of ultrasound technology with multicomponent reactions to facilitate the rapid construction of piperidone derivatives by an one-pot and four-component reaction in ethanol. In comparison with conventional methods, the main advantage of ultrasound application is the significant decrease in the reaction time and all the proposed reactions allowed the preparation of products in good yield without any further complicated refinement.The structures of the products were determined by IR,1H NMR and HRMS. Furthermore, the structures of some products were confirmed by13C NMR and X-ray analysis. And a possible reaction mechanism of the reaction was aslo proposed.