2,6-DISUBSTITUTED PYRIDINES AND 2,4-DISUBSTITUTED PYRIMIDINES AND THEIR USE, HERBICIDAL AGENTS AND METHOD OF FIGHTING UNDESIRED PLANT GROWTH

摘要

The new pyridine and pyrimidine derivatives of general formula (I), wherein A represents an optionally substituted aryl group or an optionally substituted 5- or 6-membered nitrogen-containing heteroaromatic group or a difluorobenzodioxolyl group; m represents an integer from 0 to 5; n represents an integer from 0 to 2; R<1> (or each R<1>) independently represents a hydrogen atom, an halogen atom, an optionally substituted alkyl, alkenyl, alkinyl, alkoxy, alkoxyalkyl, dialkoxyalkyl, alkoxyalkoxy, alkylthio, amino, alkylamino, dialkylamino, alkoxyamino or formamidino group; R<2> (or each R<2>) independently represents a hydrogen atom, a halogen atom, an optionally substituted alkyl, alkenyl, alkinyl, alkoxy, alkylthio, alkylsulphonyl or alkylsulfinyl group or a nitro, cyano, haloalkyl, haloalkoxy or haloalkylthio group; X represents an oxygen or sulphur atom; and Z represents a nitrogen atom or a CH group; with the proviso that if A represents a 1-methyl-3-trifluoromethyl-pyrazol-5-yl group, n is 0, X represents an oxygen atom and Z represents a CH group , then R<2>m does not represent hydrogen or 3-trifluoromethyl or 2,4-dichloro or 2,4-dimethyl, can be prepared by conventional methods and are particularly useful as herbicides.