VERFAHREN ZUR HERSTELLUNG NEUER PIPERAZINYLALKYL-3(2H)-PYRIDAZINONE

The invention relates to new piperazinylalkyl-3(2H)-pyridazinones of the formula I in which the radicals R1 represents hydrogen, phenyl, benzyl, or (C1-C6)-alkyl which is unsubstituted or substituted one or more times by hydroxyl, piperidine, morpholine or by a group NR4R5 in which R4 and R5 can be identical or different and which represent hydrogen, methyl or ethyl, R2 and R3 represent hydrogen, halogen, (C1-C6)-alkoxy or (C1-C6)-alkyl, where at least one of the radicals R2 or R3 denotes hydrogen, R6 represents hydrogen, (C1-C4)-alkyl, phenyl, benzyl or phenylethyl, B represents (C1-C7)-alkylene which is unsubstituted or substituted one or more times by hydroxyl, (C1-C4)-alkyl or by the group NR4R5 and which can optionally be closed to form an alicyclic 4- to 7-membered ring, R8 and R9, which can be identical or different, represent hydrogen or (C1-C6)-alkyl and Z represents phenyl, naphthyl, pyridyl or thiazolyl, each of which can be unsubstituted or substituted one or more times by (C1-C6)-alkyl, (C1-C6)-alkoxy, benzyloxy, trifluoromethyl, halogen, nitro, (C3-C7)-cycloalkoxy, (C1-C4)-alkylthio, trifluoromethylthio or by the group NR4R5, the pharmaceutically utilizable salts thereof, a process for the preparation thereof and the use thereof as medicament for the treatment of hypertension, cardiac insufficiency and disturbances of peripheral circulation.