Butyric acid derivatives.

摘要

Compounds of formula in which A is a substituted or unsubstituted, aromatic or non-aromatic, mono- or bicyclic, heterocyclic radical which is bonded to X via a carbon atom; R1 and R2 independently of one another are hydrogen or C1-C6-alkyl; X is NR3, O or S; and R3 is hydrogen or C1-C4-alkyl, in free form or in salt form, can be used as agrochemical active substances and can be prepared in a manner known per se.