RESOLVING PROCESS FOR PRODUCING ENANTIOMERS OF 2-/4-(5-TRIFLUOROMETHYL-2-PYRIDYLOXY)-PHENOXY/-PROPANOIC ACID

The invention relates to novel, herbicidally active 2-[4-(5-trifluoromethyl-2-pyridyloxy)phenoxy]propionic acid derivatives of the general formula (I), wherein A depends on the value of n in such a way that: 1) when n is 0 (zero), A stands for an -NR R substituted amino group, wherein a) R stands for hydrogen; R means a C1-4alkyl, C2-4alkenyl, C4-7cycloalkyl, heteroaryl-C1-4alkyl group or a -B-NR R group, where B stands for a straight or branched chain C2-4 alkylene group; R and R are C1-4alkyl groups or R and R together form an alicyclic group containing 2 to 6 methylene groups and the cycle, when consisting of 6 members, may contain an oxygen or an additional substi tuted or unsubstituted nitrogen in 4-position related to the nitrogen; b) R and R are different from hydrogen and represent a C1-4alkyl or C2-4alkylene group; or R and R together form an alicyclic group containing 2-6 methylene groups and the ring, when consisting of 6 members, may contain an oxygen in 4-position related to the nitrogen; 2) when n is other than 0 (zero) (n is 1 or 2), A stands for: a) an -NR R disubstituted amino group, wherein R and R represent a C1-4alkyl or C2-4alkenyl group; or R and R together form an alicyclic group containing 2 to 6 methylene groups, and the ring, when consisting of 6 members, may contain an oxygen or an additional substituted or unsubstituted nitrogen in 4-position related to the nitrogen, the alicyclic ring optionally being substituted by one or more methyl group(s); b) or an -O-N=C(CH3)2 group. The invention also relates to herbicide compositions containing the compounds of the general formula (I) as active ingredients as well as to a process for the preparation of these compounds and compositions. The compounds of the general formula (I) selectively kill the monocotyledonous weeds and thus, they can be used for killing monocotyledonous weeds in dicotyledonous cultures.