Plant protecting and regulating compositions – Plant growth regulating compositions – Organic active compound containing
Reexamination Certificate
2000-11-08
2002-09-10
Chang, Ceila (Department: 1626)
Plant protecting and regulating compositions
Plant growth regulating compositions
Organic active compound containing
C546S256000, C546S276100, C546S275400
Reexamination Certificate
active
06448204
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to certain novel 2-aryloxy-4-methyl-6-pyrazol-1-yl-pyridines, to the preparation of such compounds, to herbicidal compositions containing such compounds, and to a method of combating undesired plant growth using such compounds.
Pyridines and their derivatives have many uses in the pharmaceutical area as well as in agriculture (herbicides, fungicides, acaricides, anthelmintics, bird repellents), as reagents, intermediates and chemicals for the polymer and textile industry.
The International patent application WO 96/06096 discloses 2-azol-2-yl-5-aryloxypyridines in which the azolyl moiety contains at least two heteroatoms in the 1- and 3-position.
The broad generic formula of the International patent application WO 98/40379 embraces heteroaryl-(hetero-)aryloxypyri(mi)dines in which the heteroaryl moiety is a 5-membered ring is attached to the pyri(mi)dine group via a nitrogen atom of the heteroaryl moiety.
However, none of these documents discloses 2-(hetero-)aryloxy-4-methyl-6-pyrazol-1-ylpyridines.
Although many of the known compounds show considerable activity against various weeds, they are not completely satisfying with regard to their selectivity or because of their persistence.
The compounds according to the present invention combine high herbicidal activity with good selectivity and a desirable rate of degradation in soil.
SUMMARY OF THE INVENTION
The present invention provides novel compounds of the general formula I
wherein
A represents an optionally substituted aryl group or an optionally substituted 5- or 6-membered nitrogen- or sulfur-containing heteroaromatic group or a difluorobenzodioxolyl group;
or an agriculturally acceptable salt or N-oxide thereof;
The new compounds show an excellent selective herbicidal activity in certain crops, such as maize and rice, and degrade well in soil.
It is an object of the present invention to provide novel herbicidal compounds.
It is another object of the invention to provide methods for controlling undesired plant growth by contacting said plants with a herbicidally effective amount of the new compounds.
It is another object of the invention to provide selective herbicidal compositions containing the new compounds as active ingredients.
These and other objects and features of the invention will become more apparent from the detailed description set forth hereinbelow.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
It has surprisingly been found that the novel compounds of formula I, in which A has the meaning given above, show excellent herbicidal activity against a broad range of weeds and are much more active than those disclosed by the International Patent Application WO 98/40379.
An aryl group as substituent or part of other substituents or in the definition of A is suitably an optionally substituted phenyl group. Within the definition of A the 5- or 6-membered heteroaryl group comprises optionally substituted 5- or 6-membered heterocycles containing one or more nitrogen and/or oxygen and/or sulfur atoms, 1 to 3 nitrogen atoms being preferred. Examples of such groups are pyrazolyl, imidazolyl, triazolyl, tetrazolyl, thienyl, pyridyl, pyrazinyl, pyrimidyl, pyridazinyl, isoxazolyl, isothiazolyl and triazinyl groups. As far as A is concerned, the definition “aryl” also includes bicyclic systems which consist of a benzene ring fused with a 5- or 6-membered heterocyclic ring as defined above and in turn the 5- or 6-membered heterocycles may be fused with a benzene ring.
One especially preferred embodiment of the invention is a compound in which A is a difluorobenzodioxolyl group of formula
A preferably represents a phenyl, pyridyl, thienyl or pyrazolyl group being substituted by one or more of the same or different substituents selected from halogen atoms, alkyl groups, alkoxy groups, cyano groups, haloalkyl groups, haloalkoxy groups, alkylthio groups, haloalkylthio groups and SF
5
groups, and preferably has a substituent in the meta-position relative to the point of attachment; more preferably A is meta-substituted by a fluorine or chlorine atom, or a trifluoromethyl, trifluoromethoxy or difluoromethoxy group. If A represents a thienyl group, it may be attached in the 2- or 3-position with respect to the sulfur atom. 3-thienyl groups are preferred.
Generally, if any of the above mentioned moieties comprises an alkyl, alkenyl or alkynyl group, such groups, unless otherwise specified, may be linear or branched and may contain 1 to 6, preferably 1 to 4, carbon atoms. Examples of such groups are methyl, ethyl, propyl, vinyl, allyl, propargyl, isopropyl, butyl, isobutyl and tertiary-butyl groups. The alkyl portion of a haloalkyl, haloalkoxy, haloalkylthio, alkylthio or alkoxy group suitably has from 1 to 4 carbon atoms, preferably 1 or 2 carbon atoms. The number of carbon atoms in the alkoxyalkyl, alkoxyalkoxy or dialkoxyalkyl groups is up to 6, preferably up to 4, e.g. methoxymethyl, methoxymethoxy, methoxyethyl, ethoxymethyl, ethoxyethoxy, dimethoxymethyl.
“Halogen” means a fluorine, chlorine, bromine or iodine atom, preferably fluorine, chlorine or bromine. Haloalkyl moieties of any groups within the definitions used herein and as such can contain one or more halogen atoms. Haloalkyl, haloalkoxy and haloalkylthio are preferably mono-, di-, tri- or perfluoroalkyl, -alkoxy and -alkylthio, especially trifluoromethyl, pentafluoroethyl, trifluoromethoxy, difluoromethoxy, difluoromethylthio, trifluoromethylthio or 2,2,2-trifluoroethoxy groups.
When any groups are designated as being optionally substituted, the optional substituent groups may be any of those customarily employed in the modification and/or development of pesticidal compounds and are especially substituents that maintain or enhance the herbicidal activity associated with the compounds of the present invention, or influence persistence of action, soil or plant penetration, or any other desirable property of such herbicidal compounds.
There may be one or more of the same or different substituents present in each part of the molecules. In relation to moieties defined above as comprising an optionally substituted alkyl group, including alkyl parts of haloalkyl, alkoxy, alkylthio, haloalkoxy, alkylamino and dialkylamino groups, specific examples of such substituents include phenyl, halogen atoms, nitro, cyano, hydroxyl, C
1-4
-alkoxy, C
1-4
-haloalkoxy and C
1-4
-alkoxycarbonyl groups.
In relation to moieties defined above as comprising an optionally substituted aryl or heteroaryl group, optional substituents include halogen, especially fluorine, chlorine and bromine atoms, and nitro, cyano, amino, hydroxy, phenoxy, C
1-4
-alkyl, C
1-4
-alkoxy, C
1-4
-haloalkyl, C
1-4
-haloalkenyl, C
1-4
-haloalkoxy, C
1-4
-haloalkylthio, C
1-4
-alkylsulfonyl and halosulfanyl groups such as SF
5
. In the case of phenyl-groups 1 to 5 substituents may suitably be employed, in the case of thienyl-groups 1 to 3 substituents may suitably be employed, 1 or 2 substituents being preferred.
One skilled in the art will appreciate that not all nitrogen containing heterocycles can form N-oxides; one skilled in the art will recognize those nitrogen atoms which can form N-oxides. Synthetic methods for the preparation of N-oxides of heterocycles are very well known by one skilled in the art including the oxidation of heterocycles with peroxy acids such as peracetic acid and m-chloroperbenzoic acid (MCPBA), hydrogen peroxide, alkylhyroperoxides such as tert-butyl hydroperoxide. Such methods for the preparation of N-oxides have been described and reviewed in the literature, as for example: T. L. Gilchrist in
Comprehensive Organic Synthesis,
vol. 7, pp 748-750 and in
Advances in Heterocyclic Chemistry,
vol. 9, pp 285-291, vol. 22, pp 390-392 and vol. 43, pp 149-161, A. R. Katritzky. Ed., Academic Press.
Compounds of the invention include compounds of formula I, isotopes thereof, geometric and stereoisomers thereof, N-oxides thereof, and agriculturally suitable salts thereof. The compounds of the invention can exist as one or more stereoisomers. The va
Baltruschat Helmut Siegfried
Kleemann Axel
Maier Thomas
Scheiblich Stefan
BASF - Aktiengesellschaft
Chang Ceila
Keil & Weinkauf
Small Andrea D.
LandOfFree
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