Compounds of the general formula or salts thereof in which R 1 is heteroaryl, excluding thienyl, where the heteroaryl radical is unsubstituted or substituted by halogen, cyano, nitro, (C 1 -C 6)alkyl, (C 2 -C 6)alkenyl, (C 2 -C 6)alkynyl, (C 3 -C 8) cycloalkyl, (C 3 -C 8) cycloalkenyl, (C 1 -C 6)alkoxy and (C 1 -C 6)alkylS p, where the latter seven radicals are unsubstituted or are substituted by one or more radicals from the group of halogen, cyano, (C 1 -C 6)alkoxy and (C 1 -C 6)alkylS p, R 2 is hydrogen, halogen, cyano, nitro, (C 1 -C 6)alkyl, (C 2 -C 6)alkenyl, (C 2 -C 6)alkynyl, (C 3 -C 8) cycloalkyl, (C 3 -C 8)cycloalkenyl, (C 1 -C 6)alkoxy and (C 1 -C 6)alkyls p, where the latter seven radicals are unsubstituted or substituted by one already more radicals from the group of halogen, cyano, (C 1 -C 6)alkoxy and (C 1 -C 6)alkylS p, R 3 is hydrogen and (C 1 -C 6)alkyl, R 4 is hydrogen, (C 1 -C 18)alkyl, (C 1 -C 18)haloalkyl, (C 1 -C 18)cyanoalkyl, (C 2 -C 18)alkenyl, (C 2 -C 18)alkynyl, (C 3 -C 12)cycloalkyl, (C 3 -C 12)cycloalkenyl, aryl, heteroaryl, (C 1 -C 18)alkoxy- (C 1 -C 18)alkyl, (C 1 -C 18)haloalkoxy - (C 1 -C 18)alkyl, (C 1 -C 18)alkoxy- (C 1 -C 18)haloalkyl, (C 1 -C 18)alkylthio- (C 1 -C 18)alkyl, (C 1 -C 18)haloalkylthio- (C 1 -C 18)alkyl, (C 2 -C 18)haloalkenyl, (C 2 -C 18)haloalkynyl, heterocyclyl- (C 1 -C 18)alkyl, aryl-(C 1 -C 18)alkyl, (C 3 -C 12)cycloalkyl - (C 1 -C 18)alkyl, (C 1 -C 18)alkoxycarbonyl - (C 1 -C 18)alkyl, and (C 1 -C 18)alkoxycarbonyl- (C 3 -C 12)cycloalkyl - (C 1 -C 18)alkyl, or a radical of the formula -NR a R b or - N=CR c R d, where, in the former 2 radicals, each of the R a, R b, R c and R d radicals is independently hydrogen, (C 1 -C 4)alkyl, (C 2 -C 4)alkenyl, (C 2 -C 4)alkynyl, benzyl, substituted benzyl, phenyl or substituted phenyl or R a and R b together with the nitrogen atom may form a 3- to 8-membered heterocycle which may contain one or two further ring heteroatoms from the group of N, O and S and which is unsubstituted or substituted by one or more radicals from the group of (C 1 -C 4)-alkyl and (C 1 -C 4)-haloalkyl, or R c and R d together with the carbon atom are a 3- to 8-membered carbocyclic or heterocyclic radical which may contain 1 to 3 ring heteroatoms from the group of N, O and S, where the carbocyclic or heterocyclic radical is unsubstituted or substituted by one or more radicals from the group of (C 1 -C 4)-alkyl and (C 1 -C 4)-haloalkyl, m is a number from 0 to 5, and p is 0, 1 or 2. R 1 is heteroaryl, excluding thienyl, where the heteroaryl radical is unsubstituted or substituted by halogen, cyano, nitro, (C 1 -C 6)alkyl, (C 2 -C 6)alkenyl, (C 2 -C 6)alkynyl, (C 3 -C 8) cycloalkyl, (C 3 -C 8) cycloalkenyl, (C 1 -C 6)alkoxy and (C 1 -C 6)alkylS p, where the latter seven radicals are unsubstituted or are substituted by one or more radicals from the group of halogen, cyano, (C 1 -C 6)alkoxy and (C 1 -C 6)alkylS p, R 2 is hydrogen, halogen, cyano, nitro, (C 1 -C 6)alkyl, (C 2 -C 6)alkenyl, (C 2 -C 6)alkynyl, (C 3 -C 8) cycloalkyl, (C 3 -C 8)cycloalkenyl, (C 1 -C 6)alkoxy and (C 1 -C 6)alkyls p, where the latter seven radicals are unsubstituted or substituted by one already more radicals from the group of halogen, cyano, (C 1 -C 6)alkoxy and (C 1 -C 6)alkylS p, R 3 is hydrogen and (C 1 -C 6)alkyl, R 4 is hydrogen, (C 1 -C 18)alkyl, (C 1 -C 18)haloalkyl, (C 1 -C 18)cyanoalkyl, (C 2 -C 18)alkenyl, (C 2 -C 18)alkynyl, (C 3 -C 12)cycloalkyl, (C 3 -C 12)cycloalkenyl, aryl, heteroaryl, (C 1 -C 18)alkoxy- (C 1 -C 18)alkyl, (C 1 -C 18)haloalkoxy - (C 1 -C 18)alkyl, (C 1 -C 18)alkoxy- (C 1 -C 18)haloalkyl, (C 1 -C 18)alkylthio- (C 1 -C 18)alkyl, (C 1 -C 18)haloalkylthio- (C 1 -C 18)alkyl, (C 2 -C 18)haloalkenyl, (C 2 -C 18)haloalkynyl, heterocyclyl- (C 1 -C 18)alkyl, aryl-(C 1 -C 18)alkyl, (C 3 -C 12)cycloalkyl - (C 1 -C 18)alkyl, (C 1 -C 18)alkoxycarbonyl - (C 1 -C 18)alkyl, and (C 1 -C 18)alkoxycarbonyl- (C 3 -C 12)cycloalkyl - (C 1 -C 18)alkyl, or a radical of the formula -NR a R b or - N=CR c R d, where, in the former 2 radicals, each of the R a, R b, R c and R d radicals is independently hydrogen, (C 1 -C 4)alkyl, (C 2 -C 4)alkenyl, (C 2 -C 4)alkynyl, benzyl, substituted benzyl, phenyl or substituted phenyl or R a and R b together with the nitrogen atom may form a 3- to 8-membered heterocycle which may contain one or two further ring heteroatoms from the group of N, O and S and which is unsubstituted or substituted by one or more radicals from the group of (C 1 -C 4)-alkyl and (C 1 -C 4)-haloalkyl, or R c and R d together with the carbon atom are a 3- to 8-membered carbocyclic or heterocyclic radical which may contain 1 to 3 ring heteroatoms from the group of N, O and S, where the carbocyclic or heterocyclic radical is unsubstituted or substituted by one or more radicals from the group of (C 1 -C 4)-alkyl and (C 1 -C 4)-haloalkyl, m is a number from 0 to 5, and p is 0, 1 or 2.