Efficient Synthesis Of Several Five Or Six Ring Heterocycles Containing Sulfur And Nitrogen

Heterocycles have lots of applications in wide areas including pesticide, pharmaceuticals, dyes and so on. They have been the focus people are studying nowadays. Consequently, exporing an facile way to synthesize heterocycles has a good value of research and application, so we have explored facile synthetic methods of some kinds of these heterocycles which have good biological activities.The thesis mainly consists of five chapters.Chapter one made a review of the progress about the synthesis and applications of4-thiazinidinones,4-pyrimidinones,4-thiazolidinones in recent years.Chapter two studied that in the solvent system of acetone/water, N-(3-chloropropionyl)-N-arylthioureas took ring closure reactions with the catalyst of NaOH to generate4-thiazinidinones,4-pyrimidinones,4-thiazolidinones. Compared with traditional methods, this method had many advantages:firstly, the reactions were conducted under milder conditions; secondly, the reaction time was shorter, lastly, the yield of the reaction was higher. We also confirmed the structures of some heterocycles we had synthesized further through X-ray diffraction.Chapter three studied that2-chloroacetyl chloride reacted with N-benzoyl-N-arylthioureas to generate2-benzoylimino-3-aryl-4-thiazol- idinones in [bmim]BF4/EA. In this reaction, ionic liduids [bmim]BF4mixed with EA was the solvent, the reaction could be conducted at room temperature, and the reaction time was shorter, yield was higher than traditional methods, So this method reflected the advantages of ionic liduids as the solvent.Chapter four described the synthisis of some thiazole compounds in acetone/water(V:V=3:1) or in water alone. Ethyl3-bromo-2-oxopropano-ate reacted with thioureas to generate thiazole compounds at high yields when it was conducted at room temperature in acetone/water(V:V=3:1) after1h, Compared with traditional methods, the method we explored had the following features:milder conditions, more simplicity of operation, shorter reaction time, higher yields. According to the thioureas which could be dissolved in water when heated, this reaction could be conducted in water, so it avoided the use of organic solvent. We also explored the functions of water in the reaction.Chapter five is about the1H NMR and IR spectra of the heterocycles we have synthesized.