Piperazinyl-(hydroxy)propyl derivs. of pyrido-pyridazine cpds. - with hypotensive activity and effects on heart rate and cardiac contraction

摘要

Pyrido-pyridazine derivs. of formula (I) and their suitable acid addn. salts are new. In the formula, X is a nitrogen atom in the 1-, 2-, 3- or 4-position of the phenyl nucleus; R1 is 2-, 3- or 4-pyridyl opt. substd. by a halogen atom, or is phenyl opt. mono- or disubstd. by halogen, NO2, CF3, 1-3C alkyl and/or 1-3C alkoxy; R2 is H or OH; and R3 is H, halogen or 2-5C carbalkoxy. (I) have a hypotensive effect on arterial blood pressure. They also reduce heart rate and cardiac contractility. (I) are useful for the treatment of hypertension and coronary disease. Typical cpd. is 6- 3- 4-(2-pyridly)-1-piperazinyl -2-hydroxypropyl -pyrido 2,3-d pyridazin-5(6H)-one.