This application is a 371 of PCT/EP98/02878 filed May 15, 1998, now WO 98/54137 Dec. 3, 1998.
The present invention relates to novel substituted 2-phenylpyridines of the formula I 
in which the substituents and the index m have the following meanings:
m is 0 or 1;
is halogen, C1-C4-haloalkyl, C1-C4-haloalkoxy, C1-C4-alkylthio, C1-C4-alkylsulfinyl, C1-C4-alkylsulfonyl, C1-C4-haloalkylthio or cyano;
R2 is fluorine or trifluoromethyl;
R3 is hydrogen or halogen;
R4 is halogen or cyano;
R5 is CO2R6, OR7, SR7, C(R8)xe2x95x90Nxe2x80x94Oxe2x80x94R7 or C(R8)xe2x95x90C(R8)xe2x80x94COxe2x80x94Oxe2x80x94R6, where
R6 is hydrogen, an unsubstituted or halogen-substituted C1-C8-alkyl-, C3-C6-alkenyl- or C3-C6-alkynyl radical; C1-C4-alkoxy-C1-C4-alkyl, C1-C6-alkoxycarbonyl-C1-C4-alkyl, C3-C4-alkenyloxycarbonyl-C1-C4-alkyl, C3-C4-alkynyloxycarbonyl-C1-C4-alkyl or C1-C4-alkoxy-(C1-C4-alkoxy)carbonyl-C1-C4-alkyl;
R7 may have the meaning of R6 or may be CH2xe2x80x94CO2[C1-C4-alkylene)]xe2x80x94CO2R9 or CH[C1-C4-alkyl]CO2xe2x80x94[C1-C4-alkylene]xe2x80x94CO2R9;
R8 is hydrogen, halogen or C1-C4-alkyl and
R9 is hydrogen or C1-C4-alkyl,
and the agriculturally useful salts of the compounds I.
Furthermore, the invention relates to
a process for preparing the compounds I and
intermediates of the formula II,
herbicides and compositions for the desiccation and/or defoliation of plants which comprise the compounds I as active substances,
methods for controlling undesirable vegetation and for the desiccation and/or defoliation of plants using the compounds I.
Substituted 2-phenyl-3-chloropyridines having herbicidal activity are already known from WO 95/02580, WO 95/02590 and WO 97/11059.
However, the herbicidal activity of the prior art compounds with respect to harmful plants is not always entirely satisfactory.
It is an object of the present invention to provide novel herbicidally active compounds which allow better selective control of undesirable plants. It is a further object to provide novel compounds which have desiccant/defoliant action.
We have found that these objects are achieved by the substituted 2-phenylpyridines of the formula I defined at the outset having herbicidal activity, and by the novel intermediates II for their preparation.
Depending on the substitution pattern, the compounds of the formula I can contain one or more chiral centers, in which case they exist in the form of enantiomer or diastereomer mixtures. The invention relates to the pure enantiomers or diastereomers and also to mixtures thereof.
The substituted 2-phenylpyridines I where R6, R7 and R9=hydrogen may be present in the form of their agriculturally useful salts, the kind of salts usually not being important. Suitable in general are the salts of those bases whose herbicidal activity is not impaired in comparison to the free compound I.
Suitable salts are in particular those of the alkali metals, preferably sodium salts and potassium salts, of the alkaline earth metals, preferably calcium salts and magnesium salts, those of the transition metals, preferably zinc salts and iron salts, and ammonium salts where the ammonium ion, if desired, may carry one to four C1-C4-alkyl or hydroxy-C1-C4-alkyl substituents and/or one phenyl or benzyl substituent, preferably diisopropylammonium, tetramethylammonium, tetrabutylammonium, trimethylbenzylammonium and trimethyl-(2-hydroxyethyl)ammonium salts, furthermore phosphonium salts, sulfonium salts such as preferably tri-(C1-C4-alkyl)sulfonium salts and sulfoxonium salts such as preferably tri-(C1-C4-alkyl)sulfoxonium salts.
The terms alkyl, alkylene haloalkyl, alkoxy, carboxyalkyl, alkoxyalkyl, alkoxycarbonylalkyl, alkenyl and alkynyl used in the definition of the substituents R1, R6, R7, R8 and R9 arexe2x80x94like the term halogenxe2x80x94collective terms for individual enumerations of the individual group members. All alkyl moieties may be straight-chain or branched. The haloalkyl radical preferably carries one to five identical or different halogen atoms.
Specific meanings are, for example:
halogen: fluorine, chlorine, bromine and iodine, preferably fluorine and chlorine;
C1-C4-alkyl: methyl, ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl and 1,1-dimethylethyl;
C1-C6-alkyl: C1-C4-alkyl as mentioned above, and n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, 1-ethylpropyl, n-hexyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, 1,3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 1-ethylbutyl, 2-ethylbutyl, 1,1,2-trimethylpropyl, 1,2,2-trimethylpropyl, 1-ethyl-1-methylpropyl and 1-ethyl-2-methylpropyl;
C1-C8-alkyl: C1-C6-alkyl as mentioned above, and, inter alia, n-heptyl, n-octyl;
C3-C4-alkenyl: prop-1-en-1-yl, prop-2-en-1-yl, 1-methylethenyl, n-buten-1-yl, n-buten-2-yl, n-buten-3-yl, 1-methylprop-1-en-1-yl, 2-methylprop-1-en-1-yl, 1-methylprop-2-en-1-yl and 2-methylprop-2-en-1-yl;
C3-C6-alkenyl: C3-C4-alkenyl as mentioned above, n-penten-1-yl, n-penten-2-yl, n-penten-3-yl, n-penten-4-yl, 1-methylbut-1-en-1-yl, 2-methylbut-1-en-1-yl, 3-methylbut-1-en-1-yl, 1-methylbut-2-en-1-yl, 2-methylbut-2-en-1-yl, 3-methylbut-2-en-1-yl, 1-methylbut-3-en-1-yl, 2-methylbut-3-en-1-yl, 3-methylbut-3-en-1-yl, 1,1-dimethylprop-2-en-1-yl, 1,2-dimethylprop-1-en-1-yl, 1,2-dimethylprop-2-en-1-yl, 1-ethylprop-1-en-2-yl, 1-ethylprop-2-en-1-yl, n-hex-1-en-1-yl, n-hex-2-en-1-yl, n-hex-3-en-1-yl, n-hex-4-en-1-yl, n-hex-5-en-1-yl, 1-methylpent-1-en-1-yl, 2-methylpent-1-en-1-yl, 3-methylpent-1-en-1-yl, 4-methylpent-1-en-1-yl, 1-methylpent-2-en-1-yl, 2-methylpent-2-en-1-yl, 3-methylpent-2-en-1-yl, 4-methylpent-2-en-1-yl, 1-methylpent-3-en-1-yl, 2-methylpent-3-en-1-yl, 3-methylpent-3-en-1-yl, 4-methylpent-3-en-1-yl, 1-methylpent-4-en-1-yl, 2-methylpent-4-en-1-yl, 3-methylpent-4-en-1-yl, 4-methylpent-4-en-1-yl, 1,1-dimethylbut-2-en-1-yl, 1,1-dimethylbut-3-en-1-yl, 1,2-dimethylbut-1-en-1-yl, 1,2-dimethylbut-2-en-1-yl, 1,2-dimethylbut-3-en-1-yl, 1,3-dimethylbut-1-en-1-yl, 1,3-dimethylbut-2-en-1-yl, 1,3-dimethylbut-3-en-1-yl, 2,2-dimethylbut-3-en-1-yl, 2,3-dimethylbut-1-en-1-yl, 2,3-dimethylbut-2-en-1-yl, 2,3-dimethylbut-3-en-1-yl, 3,3-dimethylbut-1-en-1-yl, 3,3-dimethylbut-2-en-1-yl, 1-ethylbut-1-en-1-yl, 1-ethylbut-2-en-1-yl, 1-ethylbut-3-en-1-yl, 2-ethylbut-1-en-1-yl, 2-ethylbut-2-en-1-yl, 2-ethylbut-3-en-1-yl, 1,1,2-trimethylprop-2-en-1-yl, 1-ethyl-1-methylprop-2-en-1-yl, 1-ethyl-2-methylprop-1-en-1-yl and 1-ethyl-2-methylprop-2-en-1-yl, preferably ethenyl and prop-2-en-1-yl;
C3-C4-alkynyl: prop-1-in-1-yl, prop-2-in-3-yl, n-but-1-in-1-yl, n-but-1-in-4-yl, n-but-2-in-1-yl;
C3-C6-alkynyl: C3-C4-alkynyl as mentioned above, and n-pent-1-in-1-yl, n-pent-1-in-3-yl, n-pent-1-in-4-yl, n-pent-1-in-5-yl, n-pent-2-in-1-yl, n-pent-2-in-4-yl, n-pent-2-in-5-yl, 3-methylbut-1-in-1-yl, 3-methylbut-1-in-3-yl, 3-methylbut-1-in-4-yl, n-hex-1-in-1-yl, n-hex-1-in-3-yl, n-hex-1-in-4-yl, n-hex-1-in-5-yl, n-hex-1-in-6-yl, n-hex-2-in-1-yl, n-hex-2-in-4-yl, n-hex-2-in-5-yl, n-hex-2-in-6-yl, n-hex-3-in-1-yl, n-hex-3-in-2-yl, 3-methylpent-1-in-1-yl, 3-methylpent-1-in-3-yl, 3-methylpent-1-in-4-yl, 3-methylpent-1-in-5-yl, 4-methylpent-1-in-1-yl, 4-methylpent-2-in-4-yl and 4-methylpent-2-in-5-yl, preferably prop-2-in-1-yl, 1-methylprop-2-in-1-yl;
C1-C3-fluoroalkyl: C1-C3-alkyl as mentioned above where in each case 1-5 hydrogen atoms are replaced by fluorine, e.g. fluoromethyl, difluoromethyl, trifluoromethyl, 1-fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, pentafluoroethyl, 3,3,3-trifluoropropyl, preference is given to difluoromethyl, trifluoromethyl, 2,2,2-trifluoroethyl, pentafluoroethyl and 3,3,3-trifluoropropyl, particular preference is given to trifluoromethyl;
C1-C4-haloalkyl: C1-C4-alkyl as mentioned above which is partially or fully substituted by fluorine, chlorine and/or bromine, i.e. for example chloromethyl, dichloromethyl, trichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, chlorofluoromethyl, dichlorofluoromethyl, chlorodifluoromethyl, 1-fluoroethyl, 2-fluoroethyl, 2,2-difluoroethyl, 2,2,2-trifluoroethyl, 2-chloro-2-fluoroethyl, 2-chloro-2,2-difluoroethyl, 2,2-dichloro-2-fluoroethyl, 2,2,2-trichloroethyl, pentafluoroethyl and 3-chloropropyl, preferably trifluoromethyl;
C1-C4-haloalkoxy: C1-C4-alkoxy as mentioned above which is partially or fully substituted by fluorine, chlorine and/or bromine, i.e. for example chloromethoxy, dichloromethoxy, trichloromethoxy, fluoromethoxy, difluoromethoxy, trifluoromethoxy, chlorofluoromethoxy, dichlorofluoromethoxy, chlorodifluoromethoxy, 1-fluoroethoxy, 2-fluoroethoxy, 2,2-difluoroethoxy, 2,2,2-trifluoroethoxy, 2-chloro-2-fluoroethoxy, 2-chloro-2,2-difluoroethoxy, 2,2-dichloro-2-fluoroethoxy, 2,2,2-trichloroethoxy and pentafluoroethoxy, preferably C1-C2-haloalkoxy such as trifluoromethoxy;
C1-C4-alkylthio: methylthio, ethylthio, n-propylthio, 1-methylethylthio, n-butylthio, 1-methylpropylthio, 2-methylpropylthio and 1,1-dimethylethylthio, preferably methylthio, ethylthio, methylethylthio;
C1-C4-haloalkylthio: chloromethylthio, dichloromethylthio, trichloromethylthio, fluoromethylthio, difluoromethylthio, trifluoromethylthio, chlorofluoromethylthio, dichlorofluoromethylthio, chlorodifluoromethylthio, 1-fluoroethylthio, 2-fluoroethylthio, 2,2-difluoroethylthio, 2,2,2-trifluoroethylthio, 2-chloro-2-fluoroethylthio, 2-chloro-2,2-difluoroethylthio, 2,2-dichloro-2-fluoroethylthio, 2,2,2-trichloroethylthio and pentafluoroethylthio, preferably C1-C2-haloalkylthio such as trifluoromethylthio;
C1-C4-alkylsulfonyl: methylsulfonyl, ethylsulfonyl, n-propylsulfonyl, 1-methylethylsulfonyl, n-butylsulfonyl, 1-methylpropylsulfonyl, 2-methylpropylsulfonyl and 1,1-dimethylethylsulfonyl;
C1-C4-alkylsulfinyl: methylsulfinyl, ethylsulfinyl, n-propylsulfinyl, 1-methylethylsulfinyl, n-butylsulfinyl, 1-methylpropylsulfinyl, 2-methylpropylsulfinyl and 1,1-dimethylethylsulfinyl;
C1-C4-alkoxy-C1-C4-alkyl: C1-C4-alkyl which is substituted by C1-C4-alkoxy such as methoxy, ethoxy, n-propoxy, 1-methylethoxy, n-butoxy, 1-methylpropoxy, 2-methylpropoxy and 1,1-dimethylethoxy, i.e. for example CH2OCH3, CH2OC2H5, n-propoxymethyl, (1-methylethoxy)methyl, n-butoxymethyl, (1-methylpropoxy)methyl, (2-methylpropoxy)methyl, (1,1-dimethylethoxy)methyl, 2-(methoxy)ethyl, 2-(ethoxy)ethyl, 2-(n-propoxy)ethyl, 2-(1-methylethoxy)ethyl, 2-(n-butoxy)ethyl, 2-(1-methylpropoxy)ethyl, 2-(2-methylpropoxy)ethyl, 2-(1,1-dimethylethoxy)ethyl, 2-(methoxy)propyl, 2-(ethoxy)propyl, 2-(n-propoxy)propyl, 2-(1-methylethoxy)propyl, 2-(n-butoxy)propyl, 2-(1-methylpropoxy)propyl, 2-(2-methylpropoxy)propyl, 2-(1,1-dimethylethoxy)propyl, 3-(methoxy)propyl, 3-(ethoxy)propyl, 3-(n-propoxy)propyl, 3-(1-methylethoxy)propyl, 3-(n-butoxy)propyl, 3-(1-methylpropoxy)propyl, 3-(2-methylpropoxy)propyl, 3-(1,1-dimethylethoxy)propyl, 2-(methoxy)butyl, 2-(ethoxy)butyl, 2-(n-propoxy)butyl, 2-(1-methylethoxy)butyl, 2-(n-butoxy)butyl, 2-(1-methylpropoxy)butyl, 2-(2-methylpropoxy)butyl, 2-(1,1-dimethylethoxy)butyl, 3-(methoxy)butyl, 3-(ethoxy)butyl, 3-(n-propoxy)butyl, 3-(1-methylethoxy)butyl, 3-(n-butoxy)butyl, 3-(1-methylpropoxy)butyl, 3-(2-methylpropoxy)butyl, 3-(1,1-dimethylethoxy)butyl, 4-(methoxy)butyl, 4-(ethoxy)butyl, 4-(n-propoxy)butyl, 4-(1-methylethoxy)butyl, 4-(n-butoxy)butyl, 4-(1-methylpropoxy)butyl, 4-(2-methylpropoxy)butyl or 4-(1,1-dimethylethoxy)butyl, preferably n-propoxymethyl, (1-methylethoxy)methyl, 2-(n-propoxy)ethyl and 2-(1-methylethoxy)ethyl and particularly preferably CH2OCH3, CH2OC2H5, 2-methoxyethyl or 2-ethoxyethyl;
(C1-C6-alkoxy)carbonyl-C1-C2-alkyl: C1-C4-alkyl which is substituted by (C1-C6-alkoxy)carbonyl such as COOCH3, COOC2H5, n-propoxycarbonyl, COOCH(CH3)2, n-butoxycarbonyl, 1-methylpropoxycarbonyl, 2-methylpropoxycarbonyl, COOC(CH3)3, n-pentoxycarbonyl, 1-methylbutoxycarbonyl and n-hexoxycarbonyl, i.e. for example CH2xe2x80x94COOCH3, CH2xe2x80x94COOC2H5, n-propoxycarbonylmethyl, CH2xe2x80x94COOCH(CH3)2, n-butoxycarbonylmethyl, (1-methylpropoxycarbonyl)methyl, (2-methylpropoxycarbonyl)methyl, CH2xe2x80x94COOC(CH3)3, n-pentoxycarbonylmethyl, (1-methylbutoxycarbonyl)-methyl, n-Hexoxycarbonylmethyl, 1-(methoxycarbonyl)ethyl, 1-(ethoxycarbonyl)ethyl, 1-(n-propoxycarbonyl)ethyl, 1-(1-methylethoxycarbonyl)ethyl, 1-(n-butoxycarbonyl)ethyl, 1-(n-pentoxycarbonyl)ethyl, 1-(1-methylbutoxycarbonyl)ethyl, 1-(n-hexoxycarbonyl)ethyl, 2-(methoxycarbonyl)ethyl, 1-(n-hexoxycarbonyl)ethyl, 2-(methoxycarbonyl)ethyl, 2-(ethoxycarbonyl)ethyl, 2-(n-propoxycarbonyl)ethyl, 2-(1-methylethoxycarbonyl)ethyl, 2-(n-butoxycarbonyl)ethyl, 2-(1-methylpropoxycarbonyl)ethyl, 2-(2-methylpropoxycarbonyl)ethyl, 2-(1,1-dimethylethoxycarbonyl)ethyl;
(C1-C6-alkoxy)carbonyl-C1-C4-alkyl: (C1-C6-alkoxy)carbonyl-C1-C2-alkyl as mentioned above, and 2-(methoxycarbonyl)propyl, 2-(ethoxycarbonyl)propyl, 2-(n-propoxycarbonyl)propyl, 2-(1-methylethoxycarbonyl)propyl, 2-(n-butoxycarbonyl)propyl, 2-(1-methylpropoxycarbonyl)propyl, 2-(2-methylpropoxycarbonyl)propyl, 2-(1,1-dimethylethoxycarbonyl)propyl, 3-(methoxycarbonyl)propyl, 3-(ethoxycarbonyl)propyl, 3-(n-propoxycarbonyl)propyl, 3-(1-methylethoxycarbonyl)propyl, 3-(n-butoxycarbonyl)propyl, 3-(1-methylpropoxycarbonyl)propyl, 3-(2-methylpropoxycarbonyl)propyl, 3-(1,1-dimethylethoxycarbonyl)propyl, 2-(methoxycarbonyl)butyl, 2-(ethoxycarbonyl)butyl, 2-(n-propoxycarbonyl)butyl, 2-(1-methylethoxycarbonyl)butyl, 2-(n-butoxycarbonyl)butyl, 2-(1-methylpropoxycarbonyl)butyl, 2-(2-methylpropoxycarbonyl)butyl, 2-(1,1-dimethylethoxycarbonyl)butyl, 3-(methoxycarbonyl)butyl, 3-(ethoxycarbonyl)butyl, 3-(n-propoxycarbonyl)butyl, 3-(1-methylethoxycarbonyl)butyl, 3-(n-butoxycarbonyl)butyl, 3-(1-methylpropoxycarbonyl)butyl, 3-(2-methylpropoxycarbonyl)butyl, 3-(1,1-dimethylethoxycarbonyl)butyl, 4-(methoxycarbonyl)butyl, 4-(ethoxycarbonyl)butyl, 4-(n-propoxycarbonyl)butyl, 4-(1-methylethoxycarbonyl)butyl, 4-(n-butoxycarbonyl)butyl, 4-(1-methylpropoxycarbonyl)butyl, 4-(2-methylpropoxycarbonyl)butyl or 4-(1,1-dimethylethoxycarbonyl)butyl, preferably CH2xe2x80x94COOCH3, CH2xe2x80x94COOC2H5, 1-(methoxycarbonyl)ethyl or 1-(ethoxycarbonyl)ethyl;
C1-C3-alkoxy-(C1-C3-alkoxy)carbonyl-C1-C2-alkyl: (C1-C3-alkoxy)carbonyl-C1-C2-alkyl such as CH2COOCH3, CH2COOC2H5, CH2COOCH2xe2x80x94C2H5, CH2COOCH(CH3)2, CH(CH3)COOCH3, CH(CH3)COOC2H5, CH2CH2COOCH3, CH2CH2COOC2H5, CH2CH2COOCH2xe2x80x94C2H5, CH2CH2COOCH(CH3)2, 2-(COOCH3)propyl, 2-(COOC2H5)propyl, 2-(COOCH2xe2x80x94C2H5)propyl, 2-[COOCH(CH3)2]propyl, 3-(COOCH3)propyl, 3-(COOC2H5)propyl, 3-(COOCH2xe2x80x94C2H5)propyl, 3-[COOCH(CH3)2]propyl, preferably CH2COOCH3 or CH2COOC2H5, which is substituted in the C1-C3-alkoxy moiety by OCH3, OC2H5, OCH2xe2x80x94C2H5 or OCH(CH3)2, i.e. for example CH2COOCH2OCH3, CH2COOCH2OC2H5, CH2COOCH2OCH(CH3)2 or CH2COOCH2OC(CH3)3;
C1-C4-alkoxy-(C1--C4-alkoxy)carbonyl-C1-C4-alkyl: C1-C3-alkoxy-(C1-C3-alkoxy)carbonyl-C1-C2-alkyl as mentioned above where one or both of the alkoxy moieties may additionally be n-butoxy, sec-butoxy, iso-butoxy or tert-butoxy, and 2-(COOCH3)butyl, 2-(COOC2H5)butyl, 2-(COOCH2xe2x80x94C2H5)butyl, 2-[COOCH(CH3)2]butyl, 3-(COOCH3)butyl, 3-(COOC2H5)butyl, 3-(COOCH2xe2x80x94C2H5)butyl, 3-[COOCH(CH3)2]butyl, 4-(COOCH3)butyl, 4-(COOC2H5)butyl, 4-(COOCH2xe2x80x94C2H5)butyl, 4-[COOCH(CH3)2]butyl.
C1-C4-alkylene is, for example, methylene, 1,1-ethylene, 1,2-ethylene, 1,1-propylene, 1,2-propylene, 1,3-propylene, 2,2-propylene, 1,1-butylene, 1,2-butylene, 1,3-butylene, 1,4-butylene, 2,2-butylene, 2,3-butylene, 2-methyl-1,1-propylene, 2-methyl-1,2-propylene or 2-methyl-1,3-propylene, preferably methylene, 1,1-ethylene or 2,2-propylene.
With respect to the use of the substituted 2-phenylpyridines I according to the invention as herbicides and/or as desiccants/defoliants, the substituents and the index m preferably have the following meanings, in each case either alone or in combination:
m is 0,
R1 is C1-C3-fluoroalkyl, chlorine, methylsulfonyl or cyano;
R2 is fluorine or trifluoromethyl;
R3 is fluorine or chlorine;
R4 is chlorine;
R5 is CO2R6, OR7 or SR7, where
R6 is hydrogen, C1-C5-alkyl, C3-C4-alkenyl, 3-chloroprop-2-ene, C3-C4-alkynyl, C1-C3-alkoxy-C1-C2-alkyl, C1-C6-alkoxycarbonyl-C1-C2-alkyl, propargyloxycarbonyl-C1-C2-alkyl, C1-C3-alkoxy-C1-C3-alkoxycarbonyl-C1-C2-alkyl;
R7 may have the meaning of R6 or may be CH2xe2x80x94CO2[C1-C2-alkylene]xe2x80x94CO2R9 or CH[C1-C2-alkyl]xe2x80x94CO2xe2x80x94[C1-C2-alkylene]xe2x80x94CO2R9;
R8 is hydrogen, halogen or C1-C4-alkyl and
R9 is hydrogen or C1-C4-alkyl,
and the agriculturally useful salts of the compounds I.
Particular preference is given to the substituted 2-phenylpyridines Ia ({circumflex over (=)} where m=0, R2=fluorine and R4=chlorine), in particular to those compounds listed in Table A below:
Furthermore, preference is given to the substituted 2-phenylpyridines Ib ({circumflex over (=)} I where m=0, R2=trifluoromethyl, R4=chlorine), in particular to the compounds listed in Table B below:
The substituted 2-phenylpyridines are obtainable by various routes, for example by the processes described in WO 95/02580 and WO 97/11059. The preparation of corresponding 2-phenylpyridine N-oxides of the formula I (m=1) can be carried out by the method of the process described in WO 97/11059. A more recent method of coupling the pyridine and phenyl components, according to which the pyridine sulfoxides IIb and pyridine sulfones IIc are reacted with Grignard or zinc reagents III or IV to give the final products I according to the invention, was described in DE Appl. No. 196 36995.9. 
In the formulae III and IV, R3 to R5 are each as defined in claim 1 and X is in each case a halogen atom. The intermediates III and IV and the preparation thereof are described in DE Appl. No. 196 36995.9. 
The thiopyridines II can be prepared by the method of the process described in DE Appl. No. 196 36997.5. DE Appl. No. 19722661.2 discloses a particularly favorable route to thiopyridines II starting from 2-halopyridines V and thio compounds of the formula VI in the presence of a copper catalyst.
In the formula II, R1 and R2 are each as defined in claim 1. The pyridine thioethers of the formula IIa (n=0) are starting materials for the preparation of the pyridine sulfoxides IIb (n=1) and pyridine sulfones IIc (n=2); the last two compounds being employed in the coupling reaction with III or IV. Z is a C1-10-alkyl, C2-C10-alkenyl or C2-C10-alkynyl radical with or without substitution by halogen, C1-C4-alkoxy, C1-C4-alkoxycarbonyl, di-(C1-C4-alkylamino)carbonyl, cyano or nitro, or is a C3-C8-cycloalkyl radical or a C1-C4-alkylenephenyl, phenyl or naphthyl radical with or without substitution in the phenyl moiety by halogen, C1-C3-alkyl, C1-C3-alkoxy, trifluoromethyl, cyano or nitro.
The terms alkyl, alkenyl, alkynyl, alkylene, alkoxy, alkoxycarbonyl, dialkylaminocarbonyl and cycloalkyl used in the definition of the substituent Z are collective terms for individual enumerations of the individual group members. All alkyl moieties may be straight-chain or branched. The haloalkyl radical preferably carries one to five identical or different halogen atoms.
Specific examples are:
C1-C10-alkyl: C1-C8-alkyl as mentioned in the definition of substituents for R6, and n-nonyl and n-decyl;
1-phenyl with or without substitution by halogen, C1-C3-alkyl, C1-C3-alkoxy, trifluoromethyl, cyano or nitro: 2-, 3-, 4-chlorophenyl, 2-, 3-, 4-tolyl, 2-chloro-4-methylphenyl, 2,4-dichlorophenyl, 2,4,6-trichlorophenyl, 2,6-dichloro-4-methylphenyl, 2-, 3-, 4-methoxyphenyl, 2-chloro-4-methoxyphenyl, 3-chloro-4-methoxyphenyl, 2-, 3-, 4-trifluoromethylphenyl, 2-, 3-, 4-cyanophenyl, 2-, 3-, 4-nitrophenyl, 2-methyl1-4-nitrophenyl, 2-chloro-4-trifluoromethylphenyl, 2-chloro-4-nitrophenyl and unsubstituted phenyl.
Particular preference is given to those compounds II in which 
n is 1 or 2;
R1 is trifluoromethyl, chlorine, methylsulfonyl or cyano;
R2 is fluorine or trifluoromethyl and
Z is an unsubstituted or chlorine- or methoxy-substituted C1-C8-alkyl radical, or a benzyl or phenyl radical which is unsubstituted or halogen-, methyl-, C1-C3-alkoxy-, trifluoromethyl-, cyano- or nitro-substituted in the phenyl moiety.
Specifically, mention may be made, for example, of the following pyridine thioethers IIa of Tables 1-4, of the pyridine sulfoxides IIb of Table 5-8 and of the pyridine sulfones IIc of Tables 9-12.
Preference is given to the pyridine thioethers II.001-II.116 mentioned in Table 1 of Formula IIa1
Furthermore, preference is given to the pyridine thioethers IIa2.001-IIa2.116 of the formula IIa2, which differ from the compounds IIa1.001-IIa1.116 in that in position 5 of the pyridine ring, a trifluoromethyl group replaces chlorine.
Furthermore, preference is given to the pyridine thioethers IIa3.001-IIa3.116 of the formula IIa3, which differ from the compounds IIa1.001-IIa1.116 in that position 5 of the pyridine ring accommodates a methylsulfonyl group.
Furthermore, preference is given to the pyridine thioethers IIa4.001-IIa4.116 of the formula IIa4, which differ from the compounds IIa1.001-IIa1.116 in that in position 5 of the pyridine ring a cyano group replaces chlorine.
Furthermore, preference is given to the thiopyridines IIb1.001-IIb1.116 of the formula IIb1, which differ from the compounds IIa1.001-IIa1.116 in that they are the corresponding sulfoxides.
Furthermore, preference is given to the thiopyridines IIb2.001-IIb2.116 of the formula IIb2, which differ from the compounds IIa2.001-IIa2.116 in that they are the corresponding sulfoxides.
Furthermore, preference is given to the thiopyridines IIb3.001-IIb3.116 of the formula IIb3, which differ from the compounds IIa3.001-IIa3.116 in that they are the corresponding sulfoxides.
Furthermore, preference is given to the thiopyridines IIb4.001-IIb4.116 of the formula IIb4, which differ from the compounds IIa4.001-IIa4.116 in that they are the corresponding sulfoxides.
Furthermore, preference is given to the thiopyridines IIc1.001-IIc1.116 of the formula IIc1, which differ from the compounds IIa1.001-IIa1.116 in that they are the corresponding sulfones.
Furthermore, preference is given to the thiopyridines IIc2.001-IIc2.116 of the formula IIc2, which differ from the compounds IIa2.001-IIa2.116 in that they are the corresponding sulfones.
Furthermore, preference is given to the thiopyridines IIc3.001-IIc3.116 of the formula IIc3, which differ from the compounds IIa3.001-IIa3.116 in that they are the corresponding sulfones.
Furthermore, preference is given to the thiopyridines IIc4.001-IIc4.116 of the formula IIc4, which differ from the compounds IIa4.001-IIa4.116 in that they are the corresponding sulfones.
If the compounds IIa-c are prepared using 2,3-difluoro-5-trifluoromethylpyridine and thiophenol as nucleophile and using hydrogen peroxide as oxidizing agent, the reaction can be illustrated by the following scheme: 
It is also possible to use peracetic acid, sodium hypochlorite or chlorine and bromine as oxidizing agents instead of hydrogen peroxide in processes analogous to the above scheme.
Preferred embodiments of the process are specified below.
The reaction of the 2-halopyridines V with a thiol VI is advantageously carried out in the presence of a solvent at 80-250xc2x0 C., preferably 120-200xc2x0 C., particularly preferably 140-180xc2x0 C.
Solvents that are used for these reactionsxe2x80x94depending on the temperature rangexe2x80x94are hydrocarbons such as toluene and xylene, chlorinated hydrocarbons such as 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, chlorobenzene, 1,2-, 1,3- or 1,4-dichlorobenzene, ethers such as 1,4-dioxane or anisol, glycol ethers such as dimethyl glycol ether, diethyl glycol ether or diethylene glycol dimethyl ether, esters such as ethyl acetate, propyl acetate, methyl isobutyrate or isobutyl acetate, carboxamides such as DMF or N-methylpyrrolidone, nitrated hydrocarbons such as nitrobenzene, ureas such as tetraethylurea, tetrabutylurea, dimethylethyleneurea and dimethylpropyleneurea, sulfoxides such as dimethyl sulfoxide, sulfones such as dimethyl sulfone, diethyl sulfone and tetramethylene sulfone, nitriles such as acetonitrile, propionitrile, butyronitrile or isobutyronitrile; water, or else mixtures of individual solvents.
The reaction is particularly preferably carried out in the melt without the use of a solvent.
The molar ratios in which the starting materials are reacted with each other are generally 0.9-1.4, preferably 0.95-1.1, particularly preferably 0.98-1.04, for the ratio of thiol to 2-halopyridine V. The concentration of the starting materials in the solvent is 0.1-5 mol/l, preferably 0.2-2 mol/l.
The reaction is promoted by the presence of a copper catalyst. Suitable catalysts are copper oxide, salts such as copper(II) chloride, copper sulfate, copper nitrate, copper acetate and copper carbonate. Particular preference is given to using finely distributed metallic copper, for example copper powder or copper bronze. The molar amount of catalyst, based on the 2-halopyridine V, is 0.001-10, preferably 0.001-1, particularly preferably 0.001-0.1 mol %.
The reaction can also be carried out in the presence of an organic base such as, for example, triethylamine, tri-n-propylamine, N-ethyldiisopropylamine, pyridine, xcex1-, xcex2-, xcex3-picoline, 2,4-, 2,6-lutidine, N-methylpyrrolidine, triethylene diamine, dimethylaniline, N,N-dimethylcyclohexylamine, quinoline or acridine.
The reaction is preferably carried out under acidic conditions by flushing the hydrogen halide that is eliminated during the reaction out of the reaction mixture by means of an inert gas, for example nitrogen, or by letting it escape into a gas washer under autogenous pressure.
Advantageously, the 2-halopyridine V is added over a period of 10 to 60 min to a mixture of the thiol VI and the catalyst at 20-80xc2x0 C., and the mixture is then stirred for another 0.5 to 12 hours, preferably 1 to 8 hours, at 140-180xc2x0 C. to allow the reaction to go to completion.
However, it is also possible to add the thiol VI to a mixture of 2-halopyridine V and catalyst and then to complete the reaction as described above.
In the case of low-boiling 2-halopyridines V or thiols VI, the reaction can also be carried out in an autoclave.
If only one of the two starting materials has a low boiling point, the higher-boiling component can be initially charged together with the catalyst and the low-boiling component can be introduced directly at the reaction temperature of preferably 120-200xc2x0 C., particularly preferably 140-180xc2x0 C., or as a gas, at the rate of its consumption.
The reaction can be carried out under atmospheric or superatmospheric pressure, continuously or batchwise.
The oxidation of the pyridine thioethers of the formula IIa to the pyridine sulfoxides IIb and pyridine sulfones IIc is advantageously carried out with hydrogen peroxide, the pyridine sulfoxides IIb being obtained with approximately equivalent amounts of oxidant, and the pyridine sulfones IIc being obtained with approximately double the molar amount.
Examples of solvents which can be used include water, acetonitrile, carboxylic acids such as acetic acid, trifluoroacetic acid, propionic acid, alcohols such as methanol, ethanol, isopropanol, tert-butanol and chlorinated hydrocarbons such as methyl ethyl ketone. Water, methanol, acetic acid and trifluoroacetic acid are particularly preferred.
In a particularly preferred variant, the reaction can also be catalyzed by adding relatively strong acids such as trifluoroacetic acid or perchloric acid. However, suitable catalysts additionally include metal compounds, eg. transition metal oxides such as vanadium pentoxide, sodium tungstate, potassium dichromate, iron oxide tungstate, sodium tungstate/molybdic acid, osmic acid, titanium trichloride, selenium dioxide, phenylselenenic acid, vanadyl 2,4-pentanedionate.
The catalysts are generally employed in an amount of from 0.5 to 10%, but it is also possible to employ stoichiometric amounts because the inorganic catalysts can easily be filtered off and recovered.
Another preferred oxidizing agent is peracetic acid or hydrogen peroxide/acetic anhydride, possibly also the peracetic acid which is present in equilibrium in a hydrogen peroxide/acetic acid mixture.
Another preferred oxidizing agent is pertrifluoroacetic acid or the hydrogen peroxide/trifluoroacetic acid mixture or else the hydrogen peroxide/trifluoroacetic anhydride mixture.
Oxidation with hydrogen peroxide in glacial acetic acid is generally very selective, but frequently slow. The reaction time can generally be reduced by adding trifluoroacetic acid. The oxidation with hydrogen peroxide in pure trifluoroacetic acid frequently leads to the formation of the corresponding N-oxides, as described for example in Chimia 29 (1975), 466. A rapid and selective oxidation of the pyridine thioethers IIa to the corresponding sulfoxides IIb and sulfones IIc is possible using solutions of hydrogen peroxide in mixtures of acetic acid and trifluoroacetic acid in the ratio of 10:1 to 1:1, in particular 6:1 to 4:1, by volume. Therefore, particular preference is given to using these mixtures as solvent.
It is possible furthermore to use as solvent petroleum ether, the abovementioned solvents and the abovementioned catalysts.
Besides peracetic acid and pertrifluoroacetic acid, it is also possible to employ perbenzoic acid, monoperphthalic acid or 3-chloroperbenzoic acid, expediently in chlorinated hydrocarbons such as methylene chloride or 1,2-dichloroethane.
Also very suitable for oxidizing the thiols to sulfoxides or sulfones are chlorine and bromine. Favorable solvents are water, acetonitrile, dioxane, two-phase systems such as aqueous potassium bicarbonate solution/dichloromethane, and, in the case of pyridine alkyl thioethers, also acetic acid.
It is furthermore possible to employ as source of active halogen tert-butyl hypochlorite, hypochlorous and hypobromous acids, their salts, also N-halo compounds such as N-bromo- and N-chlorosuccinimide or else sulfuryl chloride.
Also favorable for the oxidation are dinitrogen tetroxide, eg. in the technically simple variant with air/nitrogen dioxide or trioxide and, for example, osmium(VIII) oxide as catalyst. The oxidation can also be carried out directly with nitric acid, in which case suitable additional solvents are acetic anhydride and acetic acid, and suitable catalysts are copper(I) and (II) bromide and chloride.
Also suitable for the oxidation is photosensitized oxygen transfer, in which case recommended photosensitizers are chlorophyll, protoporphyrin, Rose Bengal or Methylene Blue. Suitable inert solvents are hydrocarbons such as pentane, hexane, heptane, cyclohexane, chlorinated hydrocarbons such as methylene chloride, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, alcohols such as methanol, ethanol, n-propanol or isopropanol, ketones such as acetone, methyl ethyl ketone, polar aprotic solvents such as acetonitrile, propionitrile or aromatic hydrocarbons such as benzene, toluene, chlorobenzene or xylene. In place of oxygen, it is also possible to use ozone in the abovementioned solvents, plus ether, 1,4-dioxane or THF.
Besides photosensitization, catalysts can also be recommended for oxidation with oxygen, eg. oxides and sulfides of nickel, copper, aluminum, tungsten, chromium, vanadium, ruthenium, titanium, manganese, molybdenum, magnesium and iron.
Either pyridine sulfoxides IIb or their pyridine sulfones IIc are obtained depending on the stoichiometry of the oxidizing agents used. The molar ratios in which the starting materials are reacted with each other are generally 0.9-1.8, preferably 1.05-1.3, for the ratio of pyridine thioether IIa to oxidizing agent in the case of oxidation to pyridine sulfoxide IIb and generally 1.9-3.5, preferably 2.05-2.9, in the case of oxidation to pyridine sulfone IIC.
The concentration of the starting materials in the solvent is generally 0.1-5 mol/l, preferably 0.2-2 mol/l.
It is advantageous to introduce the pyridine thioether or the pyridine sulfoxide, if appropriate with one of the abovementioned catalysts, into one of the abovementioned solvents and then to add the oxidizing agent over the course of 0.25-20 hours with stirring. The addition and reaction temperatures depend on the optimum efficiency of the oxidizing agents in question and the suppression of side reactions. If photosensitized oxygen is used, the reaction is generally carried out at xe2x88x9220 to 80xc2x0 C., but in the case of metal catalysis, the reaction is generally carried out at 50 to 140xc2x0 C., and if ozone is used, the reaction is generally carried out at xe2x88x9278 to 60xc2x0 C. Owing to the limited solubility of the oxygen derivatives, they have to be introduced continuously over a prolonged period of time (up to 20 hours) into the reaction mixture until the oxidation has ended at the sulfoxide or sulfone stage. If air/nitrogen dioxide or trioxide are used, the reaction is preferably carried out at 15-150xc2x0 C. over a period of 1-15 hours. Liquid or easily soluble oxidizing agents such as hydrogen peroxide, the peracetic acid and pertrifluoroacetic acid which are formed together with acetic anhydride or in equilibrium with acetic acid and trifluoroacetic acid, respectively, hypochlorous or hypobromous acid, tert-butyl hypochlorite, chlorine or bromine, N-chlorosuccinimide or N-bromosuccinimide or nitric acid can be added over shorter periods of time of 0.25-6 hours to the reaction mixture of the pyridine thioether or sulfoxide, depending on the exothermic character of the reaction, to end the reaction after a further 1-60 hours. Moreover, preference is given to adding the liquid or dissolved oxidizing agent in portions. If hydrogen peroxide and peracetic acid or pertrifluoroacetic acid are used, the reaction is generally carried out at 0-90xc2x0 C., if tert-butyl hypochlorite is used, the reaction is generally carried out at xe2x88x9278 to 30xc2x0 C., if N-halogen compounds are used, the reaction is usually carried out at 0-30xc2x0 C., and if nitric acid is used, the reaction is usually carried out at 20 to 140xc2x0 C. If chlorine or bromine is used, a reaction temperature of 0-40xc2x0 C. is recommended.
The oxidations can be carried out under atmospheric or superatmospheric pressure, continuously or batchwise.
Advantageously, the multi-step reaction can also be carried out as a one-pot reaction, by reacting the thioethers IIa which are obtained in the first step of the synthesis in the reaction of the 2-halopyridines V with the thiols VI without isolation and purification directly to give the sulfoxides IIb or the sulfones IIc. Thus, if appropriate, the reaction product IIa is allowed to cool to 90-120xc2x0 C., a solvent, for example trifluoroacetic acid, preferably acetic acid and/or water, is added, if appropriate, and the oxidizing agent is then added at the rate of its consumption. Preferred oxidizing agents are hydrogen peroxide and especially sodium hypochlorite.
For work-up, the intermediates IIa-c are taken up in a water-imiscible solvent, acidic impurities and/or oxidizing agents are extracted using dilute bases or water, the solution is dried and the solvent is removed under reduced pressure.
The substituted 2-phenylpyridines I are usually preparable by one of the abovementioned processes. However, for economical or technical reasons it may be more advantageous to prepare some of the compounds I from similar 2-phenylpyridines which differ in the meaning of one radical.
Work-up of the reaction mixtures is usually carried out by methods known per se, for example by diluting the reaction solution with water and subsequently isolating the product by filtration, crystallization or solvent extraction, or by removing the solvent, partitioning the residue in a mixture of water and a suitable organic solvent and work-up of the organic phase to afford the product.
The substituted 2-phenylpyridines of the formula I may contain one or more chiral centers, in which case they are usually obtained as enantiomer or diastereomer mixtures. If desired, these mixtures can be separated into substantially pure isomers using the customary methods for this purpose, such as crystallization or chromatography, including chromatography over an optically active adsorbate. Pure optically active isomers can also be prepared, for example, from suitable optically active starting materials.
Those substituted 2-phenylpyridines I where R6, R7 and R9=hydrogen can be converted in a manner known per se into their salts, preferably into their alkali metal salts.
Salts of I where the metal ion is not an alkali metal ion can be prepared by cation exchange of the corresponding alkali metal salt in a conventional manner, similarly ammonium, phosphonium, sulfonium and sulfoxonium salts by means of ammonia, phosphonium, sulfonium or sulfoxonium hydroxides.
The compounds I and their agriculturally useful salts are suitable, both in the form of isomer mixtures and in the form of the pure isomers, as herbicides. The herbicidal compositions comprising I control vegetation on non-crop areas very efficiently, especially at high rates of application. They act against broad-leaved weeds and grass weeds in crops such as wheat, rice, maize, soya and cotton without causing any significant damage to the crop plants. This effect is mainly observed at low rates of application.
Depending on the application method in question, the compounds I, or herbicidal compositions comprising them, can additionally be employed in a further number of crop plants for eliminating undesirable plants. Examples of suitable crops are the following:
Allium cepa, Ananas comosus, Arachis hypogaea, Asparagus officinalis, Beta vulgaris spec. altissima, Beta vulgaris spec. rapa, Brassica napus var. napus, Brassica napus var. napobrassica, Brassica rapa var. silvestris, Camellia sinensis, Carthamus tinctorius, Carya illinoinensis, Citrus limon, Citrus sinensis, Coffea arabica (Coffea canephora, Coffea liberica), Cucumis sativus, Cynodon dactylon, Daucus carota, Elaeis guineensis, Fragaria vesca, Glycine max, Gossypium hirsutum, (Gossypium arboreum, Gossypium herbaceum, Gossypium vitifolium), Helianthus annuus, Hevea brasiliensis, Hordeum vulgare, Humulus lupulus, Ipomoea batatas, Juglans regia, Lens culinaris, Linum usitatissimum, Lycopersicon lycopersicum, Malus spec., Manihot esculenta, Medicago sativa, Musa spec., Nicotiana tabacum (N. rustica), Olea europaea, Oryza sativa, Phaseolus lunatus, Phaseolus vulgaris, Picea abies, Pinus spec., Pisum sativum, Prunus avium, Prunus persica, Pyrus communis, Ribes sylvestre, Ricinus communis, Saccharum officinarum, Secale cereale, Solanum tuberosum, Sorghum bicolor (s. vulgare), Theobroma cacao, Trifolium pratense, Triticum aestivum, Triticum durum, Vicia faba, Vitis vinifera and Zea mays. 
In addition, the compounds I may also be used in crops which tolerate the action of herbicides owing to breeding, including genetic engineering methods.
Moreover, the substituted 2-phenylpyridines I are also suitable for the desiccation and/or defoliation of plants.
As desiccants, they are suitable, in particular, for desiccating the aerial parts of crop plants such as potatoes, oilseed rape, sunflowers and soybeans. This allows completely mechanical harvesting of these important crop plants.
Also of economic interest is the facilitation of harvesting, which can be achieved by concentrating into a short period of time fruit drop, or reduction of the adherence to the tree, in citrus fruit, olives or other species and varieties of pomaceous fruit, stone fruit and nuts. The same mechanism, i.e. promotion of the formation of abscission tissue between fruit or leaf and shoot of the plant, is also important for readily controllable defoliation of useful plants, in particular cotton.
Moreover, shortening the period within which the individual cotton plants mature results in improved fiber quality after harvesting.
The compounds I, or the compositions comprising them, can be used for example in the form of ready-to-spray aqueous solutions, powders, suspensions, also highly-concentrated aqueous, oily or other suspensions or dispersions, emulsions, oil dispersions, pastes, dusts, materials for broadcasting, or granules, by means of spraying, atomizing, dusting, spreading or watering. The use forms depend on the intended purpose; in any case, they should guarantee the finest possible distribution of the active ingredients according to the invention.
Suitable as inert auxiliaries are essentially the following: mineral oil fractions of medium to high boiling point, such as kerosene and diesel oil, furthermore coaltar oils and oils of vegetable or animal origin, aliphatic, cyclic and aromatic hydrocarbons, eg. paraffin, tetrahydronaphthalene, alkylated naphthalenes and their derivatives, alkylated benzenes and their derivatives, alcohols such as methanol, ethanol, propanol, butanol and cyclohexanol, ketones such as cyclohexanone, strongly polar solvents, eg. amines such as N-methylpyrrolidone, and water.
Aqueous use forms can be prepared from emulsion concentrates, suspensions, pastes, wettable powders or water-dispersible granules by adding water. To prepare emulsions, pastes or oil dispersions, the 2-phenylpyridines I, either as such or dissolved in an oil or solvent, can be homogenized in water by means of a wetting agent, tackifier, dispersant or emulsifier. Alternatively, it is possible to prepare concentrates comprising active ingredient, wetting agent, tackifier, dispersant or emulsifier and, if desired, solvent or oil, which are suitable for dilution with water.
Suitable surfactants are the alkali metal salts, alkaline earth metal salts and ammonium salts of aromatic sulfonic acids, eg. ligno-, phenol-, naphthalene- and dibutylnaphthalenesulfonic acid, and of fatty acids, alkyl- and alkylarylsulfonates, alkyl sulfates, lauryl ether sulfates and fatty alcohol sulfates, and salts of sulfated hexa-, hepta- and octadecanols, and also of fatty alcohol glycol ethers, condensates of sulfonated naphthalene and its derivatives with formaldehyde, condensates of naphthalene or of the naphthalenesulfonic acids with phenol and formaldehyde, polyoxyethylene octylphenol ether, ethoxylated isooctyl-, octyl- or nonylphenol, alkylphenyl or tributylphenyl polyglycol ether, alkylaryl polyether alcohols, isotridecyl alcohol, fatty alcohol/ethylene oxide condensates, ethoxylated castor oil, polyoxyethylene alkyl ethers or polyoxypropylene alkyl ethers, lauryl alcohol polyglycol ether acetate, sorbitol esters, lignin-sulfite waste liquors or methylcellulose.
Powders, materials for broadcasting and dusts can be prepared by mixing or grinding the active ingredients together with a solid carrier.
Granules, eg. coated granules, impregnated granules and homogeneous granules, can be prepared by binding the active ingredients to solid carriers. Solid carriers are mineral earths such as silicas, silica gels, silicates, talc, kaolin, limestone, lime, chalk, bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate and magnesium oxide, ground synthetic materials, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate and ureas, and products of vegetable origin, such as cereal meal, tree bark meal, wood meal and nutshell meal, cellulose powders, or other solid carriers.
The concentrations of the active ingredients I in the ready-to-use preparations can be varied within wide ranges. In general, the formulations comprise approximately from 0.001 to 98% by weight, preferably 0.01 to 95% by weight of at least one active compound. The active compounds are employed in a purity of from 90% to 100%, preferably 95% to 100% (according to NMR spectrum). The compounds I according to the invention can be formulated for example as follows:
I 20 parts by weight of the active ingredient of Example No. 9 are dissolved in a mixture composed of 80 parts by weight of alkylated benzene, 10 parts by weight of the adduct of from 8 to 10 mol of ethylene oxide to 1 mol of oleic acid N-monoethanolamide, 5 parts by weight of calcium dodecylbenzenesulfonate and 5 parts by weight of the adduct of 40 mol of ethylene oxide to 1 mol of castor oil. Pouring the solution into 100,000 parts by weight of water and finely distributing it therein gives an aqueous dispersion which comprises 0.02% by weight of the active ingredient.
II 20 parts by weight of the active ingredient of Example No. 8 are dissolved in a mixture composed of 40 parts by weight of cyclohexanone, 30 parts by weight of isobutanol, 20 parts by weight of the adduct of 7 mol of ethylene oxide to 1 mol of isooctylphenol and 10 parts by weight of the adduct of 40 mol of ethylene oxide to 1 mol of castor oil. Pouring the solution into 100,000 parts by weight of water and finely distributing it therein gives an aqueous dispersion which comprises 0.02% by weight of the active ingredient.
III 20 parts by weight of the active ingredient of Example No. 6 are dissolved in a mixture composed of 25 parts by weight of cyclohexanone, 65 parts by weight of a mineral oil fraction of boiling point 210 to 280xc2x0 C. and 10 parts by weight of the adduct of 40 mol of ethylene oxide to 1 mol of castor oil. Pouring the solution into 100,000 parts by weight of water and finely distributing it therein gives an aqueous dispersion which comprises 0.02% by weight of the active ingredient.
IV 20 parts by weight of the active ingredient of Example No. 9 are mixed thoroughly with 3 parts by weight of sodium diisobutylnaphthalenesulfonate, 17 parts by weight of the sodium salt of a lignosulfonic acid from a sulfite waste liquor and 60 parts by weight of pulverulent silica gel, and the mixture is ground in a hammer mill. Finely distributing the mixture in 20,000 parts by weight of water gives a spray mixture which comprises 0.1% by weight of the active ingredient.
V 3 parts by weight of the active ingredient of Example No. 14 are mixed with 97 parts by weight of finely divided kaolin. This gives a dust which comprises 3% by weight of active ingredient.
VI 20 parts by weight of the active ingredient of Example No. 8 are mixed intimately with 2 parts by weight of calcium dodecylbenzenesulfonate, 8 parts by weight of fatty alcohol polyglycol ether, 2 parts by weight of the sodium salt of a phenol/urea/formaldehyde condensate and 68 parts by weight of a paraffinic mineral oil. This gives a stable oily dispersion.
VII 1 part by weight of the active ingredient of Example No. 6 is dissolved in a mixture composed of 70 parts by weight of cyclohexanone, 20 parts by weight of ethoxylated isooctylphenol and 10 parts by weight of ethoxylated castor oil. This gives a stable emulsion concentrate.
VIII 1 part by weight of the active ingredient No. 14 is dissolved in a mixture composed of 80 parts by weight of cyclohexanone and 20 parts by weight of Wettol(copyright) EM 31 (=nonionic emulsifier based on ethoxylated castor oil). This gives a stable emulsion concentrate.
The herbicidal compositions or the active ingredients can be applied pre- or post-emergence. If the active ingredients are less well tolerated by certain crop plants, application techniques may be used in which the herbicidal compositions are sprayed, with the aid of the spraying equipment, in such a way that as far as possible they do not come into contact with the leaves of the sensitive crop plants, while the active ingredients reach the leaves of undesirable plants growing underneath, or the bare soil surface (post-directed, lay-by).
The rates of application of active ingredient are from 0.0005 to 3.0, preferably 0.0005 to 1.0, kg/ha of active substance (a.s.), depending on the control target, the season, the target plants and the growth stage.
To widen the spectrum of action and to achieve synergistic effects, the 2-phenylpyridines I may be mixed with a large number of representatives of other herbicidal or growth-regulating active ingredients and then applied concomitantly. Suitable components for mixtures are, for example, 1,2,4-thiadiazoles, 1,3,4-thiadiazoles, amides, aminophosphoric acid and its derivatives, aminotriazoles, anilides, (het)aryloxyalkanoic acids and their derivatives, benzoic acid and its derivatives, benzothiadiazinones, 2-aroyl-1,3-cyclohexanediones, hetaryl aryl ketones, benzylisoxazolidinones, meta-CF3-phenyl derivatives, carbamates, quinolinic acid and its derivatives, chloroacetanilides, cyclohexane-1,3-dione derivatives, diazines, dichloropropionic acid and its derivatives, dihydrobenzofurans, dihydrofuran-3-ones, dinitroanilines, dinitrophenols, diphenyl ethers, dipyridyls, halocarboxylic acids and their derivatives, ureas, 3-phenyluracils, imidazoles, imidazolinones, N-phenyl-3,4,5,6-tetrahydrophthalimides, oxadiazoles, oxiranes, phenols, aryloxy- and hetaryloxyphenoxypropionic esters, phenylacetic acid and its derivatives, phenylpropionic acid and its derivatives, pyrazoles, phenylpyrazoles, pyridazines, pyridinecarboxylic acid and its derivatives, pyrimidyl ethers, sulfonamides, sulfonylureas, triazines, triazinones, triazolinones, triazolecarboxamides and uracils.
It may furthermore be advantageous to apply the compounds I, alone or in combination with other herbicides, in the form of a mixture with other crop protection agents, for example together with agents for controlling pests or phytopathogenic fungi or bacteria. Also of interest is the miscibility with mineral salt solutions, which are employed for treating nutritional and trace element deficiencies. Non-phytotoxic oils and oil concentrates may also be added.