Compounds which, in the form of the free acid, are of the general formula I ##STR1## where D is phenyl which unsubstituted or substituted by fluorine, chlorine, bromine, nitro, cyano, C.sub.1 -C.sub.4 -alkylsulfonyl, C.sub.1 -C.sub.8 -alkyl, C.sub.1 -C.sub.4 -alkoxy, carboxyl, C.sub.1 -C.sub.4 -alkoxycarbonyl or hydroxysulfonyl or by unsubstituted or substituted carbamyl or sulfamyl, andK is a radical of a heterocyclic coupling component, and the rings A and E may furthermore be substituted by methyl, methoxy, chlorine or hydroxysulfonyl.