Chemical structure and hemodynamic effects of two new pyridazinone derivatives.

Two new pyridazinone derivatives were selected among two series and assayed for their hemodynamic effects. Their synthesis is described and their chemical structure confirmed by I.R. and N.M.R. data. The 5-arylhydroxymethyl-3-pyridazinone did not induce any significant hemodynamic changes. However, the 5-dichlorobenzylidene-3-pyridazinone, intravenously injected, was active in anesthetized dogs. Moderate doses induced modifications in the heart rate, left ventricular dP/dt max and femoral blood flow and resistance.