Synthesis and Pharmacological Evaluation of 6‐Arylpyridazinones as Potent Vasorelaxants

Abstract

Preclinical Research As part of a research program to identify compounds with potent antihypertensive properties, a new series of dihydropyridazin‐3(2H)‐one analogs was synthesized and evaluated for vasodilator activity in rat thoracic aortic rings. Most of the newly synthesized compounds displayed good vasorelaxant activity as compared with SK&F‐93741 and hydralazine, with the N2‐unsubstituted 4‐isobutyramidophenylpyridazinone derivative 5 being the most potent vasorelaxant, producing vasorelaxation greater than that of hydralazine and equipotent to SK&F‐93741. A significant effect of the 6‐phenyl substituents and substitution at N‐2 position of pyridazinone nucleus on the vasodilatory activity was observed.

Pyridazinones and pyrrolones as promising Scaffolds in Medicinal Chemistry

“…The vasorelaxant activity was tested using isolated main pulmonary artery of the rabbit using Milrinone as a reference drug. R. Bansal et al, [41] synthesized a series of dihydropyridazin-3(2H)-ones and evaluated as vasodilators using rat thoracic aortic rings. Compound 40 revealed vasorelaxation activity higher than that of hydralazine and equal to SK&F-93741 (IC 50 = 0.199, 0.316 and 0.199), respectively.…”