Synthesis and vasodilator activity of some pyridazin-3(2)-one based compounds.

Hypertension is a major health problem worldwide resulting in high death rates due to its consequences and complications. Therefore, searching for new vasorelaxants is a must to find new vasodilators efficient for the treatment of different cardiovascular diseases. Different 6-phenyl-3-pyridazinone based derivatives were synthesized and screened for their vasorelaxant activity according to the reported method using hydralazine as a standard. The tested compounds revealed potent to mild activity with EC values 0.339-114.300 μM compared with hydralazine EC = 18.210 μM. The most active compounds were the acid , its ester analog and 4-methoxyphenylhydrazide derivative (EC = 0.339, 1.225 and 1.204 μM, respectively). Therefore, 6-phenylpyridazin-3(2)-one can be a hit for structural optimization to obtain promising vasorelaxants.