3(2H)-pyridazinones and pharmaceutical compositions thereof

摘要

The invention relates to novel 3(2H)-pyridazinone-derivatives of the general formula (I), pharmaceutical compositions containing them and process for their preparation. In the general formula (I) <IMAGE> (I) stands for an ethyl or propyl group substituted by a terminal halogen atom or a hydroxyl or NR1R2 group, wherein R1 represents hydrogen atom or an unsubstituted or optionally substituted benzyl group; R2 represents hydrogen atom or an unsubstituted or optionally substituted benzo[1,4]dioxan-2-yl-methyl or -ethyl group or a (CH2)n-R3 group, wherein n is 2 or 3; and R3 stands for an unsubstituted or optionally substituted phenoxy or phenylthio group; and X stands for a hydrogen or halogen atom or an unsubstituted or optionally substituted, saturated or unsaturated 5- or 6-membered heterocyclic group containing a nitrogen atom and optionally an additional heteroatom, e.g. an oxygen, sulfur or nitrogen atom, with the proviso that R is different from an ethyl or propyl group substituted terminally by a hydroxyl group or halogen atom when X represents a hydrogen or chlorine atom. The compounds of general formula (I) selectively inhibit the adrenergic alpha1 receptors, have a calcium-antagonistic effect and exert blood pressure lowering action.