Synthesis Of Heterocycles With Pyridazinone Skeleton Structure

Pyridazine, being a triazine with two adjacent nitrogen atoms, is an important structural element in pesticides and pharmaceuticals with biological activity . Pyridazinones, being heterocyclic compounds with good biological activity, play an important role in the field of pesticides and medical research. The pesticides of pyridazinones play an important role in the integrated pest control and reducing environmental pollution of pesticides because of its activity and environment-friendly features. Pyridazinones can be used as calcium sensitizers for the treatment of heart dysfunction and heart failure in cardiac medicines. They also have a certain effect in the area of anti-platelet aggregation, hypotension, anti-inflammatory, anti-shock, anti-convulsion and so on.In recent years, in the area of the pyridazinones has attracted many attentions. In this thesis, we have embarked on the synthesis of pyridazinones, and a series of significant results and developments have been achived, the main results are as follows:1,Maleic anhydride reacted with phenylhydrazine to get to pyridazine ring, and then after esterification and condensation, we got eight acylhydrazone-pyridazinone compounds and three pyrazole - pyridazinones. Besides their structures were charactered by IR, 1HNMR ,and which of the three compounds charactered by X-ray diffraction. 2,Using 2 - phenyl -3 - pyridazinone -6 - oxyacetyl hydrazine for raw materials, through the rearrangement under base, we got the 2 - phenyl -6 - hydrazine--3 - pyridazinone .We Focued on the mechanism study of the rearrangement, and gave the preliminary draw of the rearrangement's conditions . On the basis we synthesised eight pyridazinone-hydrazone compounds and seven dihydropyrazole-pyridazinones, Besides their structures were charactered by IR, 1HNMR , 13CNMR, and which of the five compounds charactered by X-ray diffraction methods.3,Through the research to 3,6 - two hydroxyl phthalazine, 2 - phenyl -3 - phthalazinone reacted with ethyl chloroacetate at different temperatures and different ratios, we initially explorated the Tautomerism of 3,6-two hydroxyl phthalazine, and proved that 6-hydroxy-3-phthalazinone is the most stable conformation. On the basis, we synthesised two pyrazole-phthalazinones.which characterized by IR, 1HNMR,etc.