Syntheses, Characterizations And Properties Of3(2H)-Pyridazinone Derivates

A comprehensive description of pyridazinone and its derivatives were reviewed at the first part of this dissertation. For their good selectivity, high biological activity and few side effects, pyridazinone has played an important role in the current pesticides and pharmaceutical researches and developments. More and more literatures were focused on the synyhesis and application of pyridazinone. Many clinical drugs as well as the commercialization of pesticides contains the pyridazinone or its derivatives. Obviously, the study of pyridazinones and their derivatives will attract more and more attentions in the developing, synthesis or creation of a new substances with high biologically active. Furthermore, some researches reported that the pyridazinones derivative can be used as a dye-sensitive materials in the dye-sensitized solar cells and organic light-emitting diode.Through extensive literature research, we found that the4,5-diholo-pyridazinone has similar properties to the popular structure in recent literatures, which mainly modified the pyridazinone at C6. The most advantages of the4,5-diholo-pyridazinone lie in the three different reactive points, which can be deritived respectively according to our needs. This feature makes the4,5-diholo-pyridazinone to be one of the key procusor in the organic synthesis, and it will do help to receal the native rules between the specific function groups we chosen and the properties the terminal molecules have. So, we have design a simple and effective way to the modification of3(2H)-pyridazinone derivatives. The major pats of our work were the synthesis of different pyridazinones with different function group, which might improved fluorescence of pyridazinone. A total of11kinds of polysubstituted pyridazinone derivatives achieved in this dissertation, including four new pyridazinones, and most of structures were conformed by IR,1H NMR and13C NMR.Some important intermediates used in our research, key materials to synthesize4,5-diholo-pyridazinone and the target products, such as mucochloric acid and mucobroric acid,4,5-dichloro--3(2H)-pyridazinone,2-phenyl-4-chloro-5-(2-bromo-ethoxy)-3(2H)-pyridazine ketones, the best reaction conditions were optimized. Some of them has gained higher yields to the literatures. Finally, UV spectra has been taken to value the fluorescence of different type of pyridazinone derivatives. Accoding to the results, the performance of pyridazinone derivatives which bearing different function groups show better absorption intensities to the origin pyridazinone, maximum absorption wavelength of the ring were red shifed obviously. The K-band of these compounds shifted to long wave region implied the better absorbtion, better fluorescent properties of the system. We also did some expliod work, which mainly concerned about the catalysis of pyridazinone at C5with different metals. Althogh we did not gain useful results, but it do build a useful foundation to the next research programme.