A compound of the general formula I ##STR1## where the indices and the substituents have the following meanings: R.sup.1 is C(CO.sub.2 CH.sub.3).dbd.CHOCH.sub.3, C(CO.sub.2 CH.sub.3).dbd.NOCH.sub.3, N(OCH.sub.3)CO.sub.2 CH.sub.3 and C(CONHCH.sub.3).dbd.NOCH.sub.3 ;R.sup.2 is cyano, halogen, C.sub.1 -C.sub.4 -alkyl and C.sub.1 -C.sub.4 -alkoxy;m is 0 or 1;R.sup.3 is cyano, halogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -haloalkyl and C.sub.1 -C.sub.4 -alkoxy;n is 0, 1, 2 or 3, it being possible for the substituents R.sup.3 to be different from each other when n is 2 or 3;R.sup.4 is hydrogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -haloalkyl, C.sub.3 -C.sub.6 -cycloalkyl and phenyl;X and Y are C.sub.1 -C.sub.6 -alkoxy, C.sub.1 -C.sub.6 -alkylthio, C.sub.1 -C.sub.6 -alkylamino, di-C.sub.1 -C.sub.6 -alkylamino or a C.sub.1 -C.sub.4 -alkylene chain which is bonded to the C atom directly or via an oxygen, sulfur and/or nitrogen atom and which can have attached to it one or two of the following substituents: oxo (.dbd.O), cyano, C.sub.1 -C.sub.4 -alkyl, C.sub.3 -C.sub.6 -cycloalkyl, C.sub.1 -C.sub.4 -alkoxycarbonyl, aryl and heteroaryl,their preparation and, their use.