SYNTHESIS AND PLATELET AGGREGATION INHIBITORY ACTIVITY OF 6-(4-SUBSTITUTED PHENYL)-4, 5-DIHYDRO -3(2H)-PYRIDAZINONES

To search for more ideal antithrombotic drugs sixteen 6-(4-substituted phenyl)-4, 5-dihydro-3(2H)-pyridazinones were designed and synthesized. Some. improvement of the synthetic method involved in constructing the piperazinyi group by cyclization of bisbromoethyl amine with 4-pyridazin0nyl anilines.Preliminary pharmacological tests showed that all of the target compounds inhibited ADP induced platelet aggregation. Compounds Ⅱ₂, Ⅱ₃ and Ⅱ₄ were more potent than CCI-17810. The 5-methylderivative of CCI-17810 (Ⅱ₄) was the most potent compound.