Asta Medica, Aktiengesellschaft

Peter Metzenauer

Jurgen Engel

Bernhard Kutscher

Stefan Szelenyi

Ulrich Werner

Ilona Fleischhauer

Hans-Reinhold Dieter

Karl-Heinz Klingler

Jurgen Schmidt

Ute Achterath-Tuckermann

Phthalazinone derivatives and their optical isomers are used as medications to combat heart rhythm disturbances, to combat pain and to break through multi-drug resistance.

Phthalazinone derivatives that modulate multi-drug resistance

Novel compounds of the formula ##STR1## where the phenyl ring can also contain a nitrogen atom instead of a CH group, R.sub.1 is C.sub.2 -C.sub.6 -alkenyl, C.sub.2 -C.sub.6 -alkynyl, hydroxy, C.sub.1 -C.sub.6 -alkoxy, C.sub.3 -C.sub.6 -alkenyloxy, C.sub.3 -C.sub.6 -alkynyloxy, C.sub.2 -C.sub.6 -alkanoyloxy, benzoyloxy, morpholinocarbonyloxy, C.sub.1 -C.sub.6 -alkyloxycarbonyloxy, C.sub.1 -C.sub.6 -alkylaminocarbonyloxy, C.sub.1 -C.sub.6 -dialkylaminocarbonyloxy or the group -Alk-A, where Alk represents C.sub.1 -C.sub.6 -alkyl, C.sub.2 -C.sub.6 -hydroxyalkyl or C.sub.3 -C.sub.6 -cycloalkyl and the symbol A represents hydrogen or other substituents. R.sub.2, R.sub.3 and R.sub.4 represent various substituents, where R.sub.1 may also be hydrogen, when R.sub.2 is the group ##STR2## and R.sub.5 represents phenyl, C.sub.1 -C.sub.4 -alkoxyphenyl or diphenylmethyl and R.sub.3 and R.sub.4 are hydrogen and their salts. The compounds provide anti-allergic, anti-asthmatic, anxiolytic and hypotensive effects.

4,5-dihydro-4-oxo-pyrrolo[1,2-a]quinoxalinones and corresponding aza

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Grundau, Germany

Peter Metzenauer