论文部分内容阅读
The application of microwave techniques for chemical synthesis has attached considerable interests in recent years because of their enhanced selectivity, reduced reaction time ,easier work-up procedure. The synthesis of thiohydantoin derivatives is useful because they display a wide range of biological activities, including anticonvulsant1, antitumor2, antinociceptive3,thyroxine ingibitory properties4, as well as herbicidal and fungicidal reagents5. Recent studies have shown that some used as synthetic precursor of the marine natural product dispacamide6, and some used to synthesis novel optically active poly(amide-imide)s7. Therefore, many methods of synthesis of thiohydantoins have been explored8～10. Generally, these reactions were carried out in solution and using volatile and poisonous solvent, with long reaction time.In order to overcome the disadvantages discussed above, avoid the use of a solvent and synthesize these valuable compounds rapidly and efficiently, we investigated a new way---solvent-free synthesis using a microwave oven.In this paper, a new and rapid solvent-free synthesis of thiohydantoins with microwave activation was studied. It was found that the addition reaction of aryl isothiocyanates and amino acid in the presence of sodium hydroxide and the cyclizative condensation of adduct in the presence of sodium hydrogen sulphate in a microwave oven takes place quickly.By this new method, twelve thiohydantoins have been synthesized in excellent yield(83～91%).This method has significant advantages such as operational simplicity, shorter reaction time, higher yields and environmental acceptability. The structures of the products were characterized by IR, MS,1H NMR, 13C NMR and elemental analysis. And more detailed work about the application of the thiohydantoins in analytical chemistry and physiological activity is in progress in our laboratory.