Synthesis Of Analogues 6-(4-Substituted-Acetaminophenyl)-4,5-Dihydro-3(2H)-Pyridazinones And Its Platelet Aggregation Inhibitory Activity

In order to search for more potent and less toxic antithrombotic agents, eleven derivatives of 6-(4-substituted-phenyl)-4, 5-dihydro~3(2H)-pyridazinones were designedand according to mechanism of action and structure-activity relationship of dihydropyridazinone compounds. All compounds were first reported and all intermediates and title compounds were confirmed by element analysis, 1H-NMR, and IR. Result of preliminary pharmacological tests showed that all title compounds exhibited potent inhibiting activity against platelet aggregation induced by ADP to a certain extent in vitro.The activity of compound () is the most potent. Compound (9), (10), (11) have the potent activities too.