Synthesis, characterization and antihypertensive activity of pyridazinone derivatives

Some 6-(substituted-phenyl)-2-(substitutedmethyl)-4,5-dihydropyridazin-3(2H)-one derivatives were synthesized by reacting 6-substituted-phenyl-4,5-dihydropyridazin-3(2H)-one with cyclic secondary amine under Mannich reaction conditions. The final compounds (15-70) were evaluated for antihypertensive activities by non-invasive method using Tail Cuff method. The compounds 16, 19, 24, 30, 39, 42 and 45 showed good antihypertensive activity.