Antihypertensive and antithrombotic activities of 6-(substitutedphenyl)-5-hydroxymethyl-4,5-dihydro-3(2H)pyridazinones

The synthesis of a series of 6-(4R-phenyl)-5-hydroxymethyl-4,5-dihydro-3(2H)pyridazinones is reported. The compounds were evaluated for their oral antihypertensive activity in rats and some of them [(V b), R = NH2] and [(V c), R = NHCOCH3] were found to induce a high decrease in systolic blood pressure. Moreover all the compounds displayed an antithrombotic activity comparable to, or greater than, that of ASA.