SYNTHESIS AND PHARMACOLOGICAL ACTIVITIES OF ETHYL DRO-6-OXO-2-(2,3,4-PYRIDYL)-3-PYRIDINECARBOXYLATES AND DERIVATIVES

The synthesis of ethyl esters of 5-cyano-1,6-dihydro-6-oxo-3-pyridinec arboxylic acids carrying as 2-substituent the 2-,3- or 4-pyridyl group is described. By alkaline hydrolysis followed by acidification, these esters gave the corresponding carboxylic acids, which were decarboxyl ated to o-2-oxo-6-(2,3,4-pyridyl)-3-pyridinecarbonitriles. As milrinon e analogues, the above compounds were tested on contractile activity a nd frequency rate of spontaneously beating atria from reserpine-treate d guinea-pigs. Ethyl 5-cyano-1, -dihydro-6-oxo-2-(2-pyridyl)-3-pyridin ecarboxylate showed an appreciable positive inotropic activity, althou gh inferior to that of milrinone; moreover, some other compounds beari ng the above 2-substitution pattern showed interesting antiinflammator y, analgesic and hypotensive activity.