3(2H)-Pyridazinone derivatives, their preparation and their use

摘要

3(2H)-Pyridazinone derivatives of the general formula I <IMAGE> in which the substituents have the following meanings: R<1> is low-molecular-weight alkyl, alkenyl, alkinyl, C3-C8-cycloalkyl, phenyl or pyridyl, in each case optionally substituted; R<2> is phenyl, pyridyl, thienyl and furanyl, in each case optionally substituted; R<3> is hydrogen, halogen, alkyl, haloalkyl, alkoxyalkyl, phenyl and phenylalkyl, it being possible for the phenyl rings to be substituted; and R<3> is furthermore C1-C4-alkyl- and dialkylamino if R<2> denotes one of the abovementioned heteroaromatic radicals; R<4> is hydrogen, halogen, alkyl, haloalkyl, alkoxyalkyl, alkyl- and dialkylamino, phenyl and phenylalkyl, it being possible for the phenyl rings to be substituted; X is O and S; Y is O, S or a single bond. al