title: 6-Aryl-4,5-dihydro-3(2H)-pyridazinones. A new class of compounds with platelet aggregation inhibiting and hypotensive activities.
abstract: This paper reports on the synthesis and pharmacological activity of 6-aryl-4,5-dihydro-3(2H)-pyridazinone derivatives. The compounds exhibit an aggregation inhibiting action on human platelets in vitro and on rat platelets under ex vivo conditions, as well as a hypotensive action on rats. The strongest pharmacological effects were found with dihydropyridazinones, which have a 6-[p-[(chloroalkanoyl)amino]phenyl] substituent, together with a methyl group in the 5-position. The antiaggregation activity of compounds of this type is in vitro up to 16000 times and ex vivo up to 370 times greater than that of acetylsalicylic acid; the hypotensive action is up to 40 times as great as that of the comparative substance dihydralazine.
mesh_terms: D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D004078:Dihydralazine / Q000494:pharmacology; D006801:Humans; D010974:Platelet Aggregation / Q000187:drug effects*; D011724:Pyridazines / Q000138:chemical synthesis / Q000494:pharmacology*; D051381:Rats
chemical_list: D011724:Pyridazines; D004078:Dihydralazine; D001241:Aspirin