KR100693131B1 - Method for improving the selectivity of 1,3-cyclohexanedione herbicide - Google Patents

Abstract

The present invention is applied after the application of a metal chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione to herbaceous plants at undesirable plant sites to selectively control undesirable plants in the intended crop. It is about how.

Description

METHOD FOR IMPROVING THE SELECTIVITY OF 1,3-CYCLOHEXANEDIONE HERBICIDE}

The present invention relates to the use of metal chelates as delivery systems for improving the selectivity of 2- (substituted benzoyl) -1,3-cyclohexanedione compounds as herbicides after emergence in crops.

Protecting crops from undesired plants that interfere with weeds and crop growth is a constantly recurring problem in agriculture. To help solve this problem, researchers in synthetic chemistry have prepared a wide range of compounds and chemical preparations that are effective in controlling these unwanted growths. Many types of chemical herbicides are disclosed in the literature and many are commercially available.

Unfortunately, many of these herbicides have shown phytotoxicity not only to the weeds to be controlled, but also to the intended crops. Therefore, there has been a long need for selective herbicides that control weeds that occur frequently when applied in a herbicidally effective amount but do not adversely affect crops.

U.S. Pat.Nos. 4,780,127, 4,938,796, 5,006,158 and 5,089,046 describe 2- (substituted benzoyl) -1,3-cyclohexanedione compounds having the following general formula:

[Wherein X, Q and Z are described later].

These dione compounds have been found to be effective pre-emergence and post-emergence herbicides for a wide range of grasses, broad-leaved weeds, and rushes. US 5,668,089 describes one of these compounds, 2- (2'-nitro-4'-trifluoromethylbenzoyl) -1,3-cyclohexanedione, as a selective herbicide of corn. PCT Application No. 97/27748 also describes that metal chelates of 2- (substituted benzoyl) -1,3-cyclohexanedione compounds have been found to be chemically stable for extended periods of time, as well as at excessive temperature conditions.

The original cyclohexanedione has a substantial phytotoxic effect. In contrast, it has now been found that metal chelates of 2- (substituted benzoyl) -1,3-cyclohexanedione will effectively control a wide range of weeds without showing any substantial phytotoxic effect on the crop itself.

Summary of the Invention

The present invention relates to a method of selectively controlling weeds and other undesirable plants in a given crop such as wheat. In one embodiment of the invention, the method comprises applying, after emergence, a herbicidally effective amount of a metal chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione to such weeds and other plant sites. In another embodiment of the present invention, the method comprises applying, after emergence, a herbicide-effective amount of a metal chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione prepared in microcapsules to the place of such weeds and other plants. It includes.

As used herein, "herbicide" is used to mean a compound that modulates or modifies plant growth. A "herbicidal effective amount" is used to indicate the amount of such compound that can produce a modulating or modifying effect. Regulatory or modifying effects include all deviations from natural development such as eradication, delay, chlorophyll, efflorescence, dwarfism and the like. "Plant" refers to all physical parts, such as seeds, seedlings, seedlings, roots, tubers, stems, stems, leaves, and fruits.

The present invention relates to the use of metal chelates of herbicide dione compounds for selectively controlling weeds and other unintended plants in a given crop such as wheat. These herbicide dione compounds have the general formula (I)

[Wherein X is a halogen atom; Straight or branched chain alkyl or alkoxy groups containing up to one or more functional groups —OR ¹ or C ₆ optionally substituted with one or more halogen atoms; Or nitro, cyano, -CO ₂ R ² -S (O) _m R ₁ , -O (CH ₂ ) _r OR ¹ , -COR ² , -OSO ₂ R ⁴ , -NR ² R ³ , -SO ₂ NR ² R ³ , -CONR ² R ³ and -CSNR ² R ³ is a functional group selected from;

R ¹ is a straight or branched chain alkyl group containing up to C ₆ optionally substituted with one or more halogen atoms;

R ² and R ³ are each independently a hydrogen atom; Or a straight or branched chain alkyl group containing up to C ₆ optionally substituted with one or more halogen atoms;

R ⁴ is a straight or branched chain alkyl, alkenyl or alkynyl group containing up to C ₆ optionally substituted with one or more halogen atoms; Or a cycloalkyl group containing C _3-6 ;

Each Z is independently halo, nitro, cyano, S (O) _m R ⁵ , OS (O) _m R ⁵ , (C ₁ -C ₆ ) alkyl, (C ₁ -C ₆ ) alkoxy, (C _1- C ₆ ) haloalkyl, (C ₁ -C ₆ ) haloalkoxy, carboxy, (C ₁ -C ₆ ) alkylcarbonyloxy, (C ₁ -C ₆ ) alkoxycarbonyl, (C ₁ -C ₆ ) alkylcarbon carbonyl, amino, (C ₁ -C ₆₎ alkylamino, having independently the stated number of carbon atoms in each alkyl group (C ₁ -C ₆₎ dialkylamino, (C ₁ -C ₆₎ alkylcarbonyl-amino, (C ₁ -C ₆₎ alkoxycarbonyl, amino, (C ₁ -C ₆₎ alkyl amino-carbonyl-amino, independently having a number of carbon atoms in each alkyl group mentioned (C ₁ -C ₆₎ dialkylamino-carbonyl Amino, (C ₁ -C ₆ ) alkoxycarbonyloxy, (C ₁ -C ₆ ) alkylaminocarbonyloxy, (C ₁ -C ₆ ) dialkylaminocarbonyloxy, phenylcarbonyl, substituted phenylcarbonyl , Phenylcarbonyloxy, substituted phenylcarbonyloxy, phenylcarbonylamino, substituted phenylcarbonylamino, phenoxy or substituted phenoxy Is;

R ⁵ is cyano; -COR ⁶ ; -CO ₂ R ⁶ ; Or -S (O) _m R ⁷ ;

R ⁶ represents a straight or branched chain alkyl group containing hydrogen or C ₆ or less;

R ⁷ is optionally substituted with (C ₁ -C ₆ ) alkyl, (C ₁ -C ₆ ) haloalkyl, (C ₁ -C ₆ ) cycloalkyl, halogen, cyano or (C ₁ -C ₆ ) alkyl ( C ₃ -C ₈ ) cycloalkyl; Or 1-3 identical or different halogen, nitro, cyano, (C ₁ -C ₄ ) haloalkyl, (C ₁ -C ₄ ) alkyl, (C ₁ -C ₄ ) alkoxy or —S (O) _m R Phenyl optionally substituted with ⁸ ;

R ⁸ is (C ₁ -C ₄₎ alkyl, halogen or cyano-substituted (C ₁ -C ₄₎ represent an alkyl, phenyl or benzyl;

Each Q is independently C ₁ -C ₄ alkyl or —CO ₂ R ⁹ (R ⁹ is C ₁ -C ₄ alkyl);

m is 0, 1 or 2;

n is 0 or an integer of 1-4;

r is 0, 2 or 3;

z is 0 or an integer from 1-6.

As used herein, "halogen" and "halo" include fluorine, chlorine, bromine and iodine atoms. In polyhalogenated functional groups, halogens may be the same or different. "Substituted" in "substituted phenylcarbonyl", "substituted phenylcarbonyloxy", "substituted phenylcarbonylamino" and "substituted phenoxy" means halo, nitro, cyano, S (O) _m R ² , (C ₁ -C ₆ ) alkyl, (C ₁ -C ₆ ) alkoxy, (C ₁ -C ₆ ) haloalkyl, (C ₁ -C ₆ ) haloalkoxy, carboxy, (C ₁ -C ₆ ) Alkylcarbonyloxy, (C ₁ -C ₆ ) alkylcarbonyl, (C ₁ -C ₆ ) alkoxycarbonyl, (C ₁ -C ₆ ) alkylcarbonylamino, amino, (C ₁ -C ₆ ) alkylamino And independently 1-5 substituents, which may be the same or different, selected from (C ₁ -C ₆ ) dialkylamino having the specified number of carbon atoms in each alkyl group.

2- (substituted benzoyl) -1,3-cyclohexanedione compounds of formula (I) are described in particular in US Pat. Nos. 4,780,127, 4,938,796, 5,006,158 and 5,089,046, which are incorporated herein by reference. It is. The herbicide 2- (substituted benzoyl) -1,3-cyclohexanedione compounds used in the present invention may be prepared by applying and applying known methods described or used in the chemical literature by the methods described in the aforementioned patent publications. Could be.

Particularly useful 2- (substituted benzoyl) -1,3-cyclohexanedione compounds for the present invention have z of 0; X is chloro, bromo, nitro, cyano, C ₁ -C ₄ alkyl, —CF ₃ , —S (O) _m R ¹ or —OR ¹ ; n is 1 or 2; Each Z independently includes those that are chloro, bromo, nitro, cyano, C ₁ -C ₄ alkyl, -CF ₃ , -OR ¹ , -OS (O) _m R ⁵ or -S (O) _m R ⁵ do. Examples of preferred cyclohexanedione compounds are 2- (2'-nitro-4'-methylsulfonylbenzoyl) -1,3-cyclohexanedione, 2- (2'-nitro-4'-methylsulfonyloxybenzoyl) -1,3-cyclohexanedione and 2- (2'-chloro-4'-methylsulfonylbenzoyl) -1,3-cyclohexanedione.

Compounds of formula (I) may exist in enol tautomeric forms that can give rise to geometric isomers. Furthermore, in some cases, various substituents may contribute to optical isomers and / or stereoisomers. All of these forms are included in the compounds useful in the present invention.

Metal chelates of 2- (substituted benzoyl) -1,3-cyclohexanedione compounds of formula (I) are described in PCT Application No. 97/27748, which is incorporated herein by reference in particular. Metal chelates of 2- (substituted benzoyl) -1,3-cyclohexanedione compounds have the following general structure:

[Wherein X, Q and Z are as defined above and Me is ^{2 such} as Cu ⁺² , Co ⁺² , Zn ⁺² , Ni ⁺² , Ca ⁺² , Al ⁺³ , Ti ⁺³ and Fe ⁺³ It represents a valent or trivalent metal ion. The herbicide metal chelates of the herbicidal 2- (substituted benzoyl) -1,3-cyclohexanedione compounds used in the present invention can be applied by the methods described in the aforementioned PCT application or by the known methods described or used in the chemical literature. And by application. Metal ions that may be useful for forming the metal chelate compounds of the present invention include ² , such as Cu ⁺² , Co ⁺² , Zn ⁺² , Ni ⁺² , Ca ⁺² , Al ⁺³ , Ti ⁺³ and Fe ^+3. And valent or trivalent metal ions. The choice of a particular metal ion to form a metal chelate compound will depend on the strength of the dion compound and the metal chelate complex being chelated. Without wishing to be bound by theory, the strength of the metal chelate complex seems to be directly related to the rate of release of the triketone from the metal chelate complex, which in turn relates to the selectivity of the metal chelate compound of the present invention. Those skilled in the art will be able to readily determine suitable metal ions for use with certain dione compounds without undue experimentation. Preferred metal ions are divalent transition metal ions, in particular Cu ⁺² , Ni ⁺² , Zn ⁺² and Co ⁺² , with Cu ⁺² being particularly preferred.

Any suitable salt that will be a divalent or trivalent transition metal ion source may be used to form metal chelates of the dione compounds of the present invention. Particularly suitable salts include chlorides, sulfates, nitrates, carbonates, phosphates and acetates.

It has also been found that the stability and activity of the herbicide metal chelate compositions of the invention are pH dependent. The pH of the metal chelate composition is about 2-10, preferably about 3-7. Generally, the pH is about 4-6 for the Cu ⁺² chelate composition; About 3-5 for Co ⁺² ; It is believed to be about 5 for Ni ⁺² and Zn ⁺² . Optimum pH of certain metal chelate compositions can be measured using routine experimental techniques.

Metal chelates of the herbicidal 2- (substituted benzoyl) -1,3-cyclohexanedione compound can generally be prepared in the same manner as the preparation of herbicides. The choice of formulation and application mode of any given herbicide compound may affect the activity and should be selected accordingly. The herbicide composition may thus be formulated in controlled release forms such as water dispersible granules, wettable powders, powders or dusts, suspensions or microcapsules. The metal chelate preparations of the herbicidal 2- (substituted benzoyl) -1,3-cyclohexanedione compounds used in the present invention can be applied to the methods described in the aforementioned patent applications or to applications of known methods described or used in the chemical literature. Or by application. Methods of microencapsulating herbicidal compositions may also be prepared by application or application of known methods described in US Pat. Nos. 4,285,720 and 4,956,129 and US Application 08 / 354,409 and described or used in the chemical literature. Will. However, the purpose of the preparation is to apply the composition in a convenient way where control is required (ie, application after appearance). "Place" is intended to include soil as well as plants.
Formulations comprising metal chelates of the herbicidal dione compounds of formula (I) may be applied in a conventional manner to the area to be controlled. Formulations comprising herbicidal metal chelates according to the invention can also be prepared as premixes with other herbicidal or mixed in tanks with one or more additional herbicidal or other agricultural compositions. Specific examples of other herbicides which may be incorporated into the herbicide preparations together with the metal chelates according to the invention are acetanilide, tralcoxidim, bromoxynil and esters thereof, thiafluamide, MCPA and esters thereof, 2,4 -D and its esters, and fluoxypyructyl.
In the practice of the present invention, metal chelates of the herbicidal 2- (substituted benzoyl) -1,3-cyclohexanedione compounds are applied after appearance to the place of the undesirable plant to be controlled. The application rate will depend on the specific plant species and the degree of control desired. Generally, an application rate of about 5-500 g / ha can be used.
The following examples are for illustrative purposes only and are not intended to be representative of the entire test performed, nor are they intended to limit the invention in any way.

Example 1

All of the metal chelate compounds used in the 1,3-cyclohexanedione preparation of this example were prepared using a mixing and milling method except for preparation C prepared using the precipitation method. Mixing and milling methods and precipitation methods are described in more detail in PCT Application No. 97/27748, which is incorporated herein by reference.

12 days later, the aluminum flats (containing soil containing 2 parts sandy loam to 1 part pit) are seeded and the 1,3-cyclohexanedione suspension formulation (in the proportions listed in Table 1 below) is gallium afarin (Catchweed) Bedro) ("GALAP"); Ketopodium alboom (ramsquatter) ("CHEAL"); Matricaria Inodora (odorless placen chamomile) ("MATIN"); And after emergence in wheat.

Flats were placed in a greenhouse and evaluated 6 and 21 days after application (“DAA”). Injury was assessed as a percentage of control, the total plant damage by all factors including inhibition of appearance, dwarfism, malformations, blight and other forms of plant damage. The control grade is 0-100%, where 0% corresponds to the untreated control and is ineffective for growth and 100% indicates complete eradication.

The observed results (three averages) are summarized in Table 1 below.                 

From these results it is clear that the phytotoxicity of the 1,3-cyclohexanedione preparations for wheat was reduced by chelation. In contrast, the herbicidal activity of 1,3-cyclohexanedione preparations on weeds and other undesirable plants was only slightly affected by chelation. It is also clear from these results that the activity of 1,3-cyclohexanedione depends on the metal ion used to form the metal chelate compound.

Example 2

The metal chelate compound used in the 1,3-cyclohexanedione suspension preparation of this example was prepared using the mixing and milling method as described in Example 1. In addition, plant species CHEAL; Amaranthus retroplexus (red root ragweed) ("AMARE"); Polygonum convolvulus (wild wheat) ("POLCO"); Brassica caber (wild mustard) ("SINAR"); Tlaspi Arbenche (Penny Criss) (THLAR "); Brassica Can Pastries (Rapseed) (" BRSNN "); Wheat (" TRZAS ") and Barley (" HORVS ") containing aluminum flats (Table below) The essentially same procedure as described in Example 1 was used to apply the 1,3-cyclohexanedione suspension formulation) after appearance, at the rates listed in II. The damage assessments were 8 and 32 DAA.

The observed results (as four averages) are summarized in Table II below.                 

These data showed a 16-fold increase in wheat selectivity upon initial evaluation compared to copper chelates of 2- (substituted benzoyl) -1,3-cyclohexanedione, Formulation J, which were unchelated formulations (Control 2). . The weed control activity of the copper chelate formulations was nearly identical to the unchelated formulations.

Example 3

The metal chelate compound used in the 1,3-cyclohexanedione preparation of this example was prepared using the mixing and milling method as described in Example 1. Control 3 and Formulation K were prepared as suspension formulations and Formulation L as microcapsules.

Using essentially the same procedure as described in Example 1, 1,3-cyclohexanedione preparations appeared in the ratios listed in Table III below on aluminum flats containing plant species AMARE, BRSNS, POLCO, SINAR and TRZAS. Then applied. Injury was assessed at 6 and 22DAA.

The observed results (with four averages) are summarized in Table III below.                 

The data showed that the copper chelates of 2- (substituted benzoyl) -1,3-cyclohexanedione (Formulation K) had improved selectivity compared to the unchelated formulation (Control 3). These data also show that the selectivity of copper chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione was further improved by microcapsules (Formulation L).

The foregoing description and examples are illustrative only and do not limit the scope of protection of the present invention.

Claims (9)

2- (2'-nitro-4'-methylsulfonylbenzoyl) -1,3-cyclohexanedione, 2- (2'-nitro-4'-methylsulfonyloxybenzoyl) -1,3-cyclohexanedione And metal chelates of 2- (substituted benzoyl) -1,3-cyclohexanedione selected from 2- (2'-chloro-4'-methylsulfonylbenzoyl) -1,3-cyclohexanedione. A method of selectively controlling undesirable plants in a crop of interest, including application to vegetation locus. The method of claim 1 wherein the metal chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione consists of a metal ion selected from the group consisting of copper, cobalt, zinc, nickel, aluminum, calcium, titanium and iron. . The method of claim 2 wherein the metal ion is copper. The method of claim 1 wherein the pH of the metal chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione is 2-10. The process of claim 4 wherein the pH of the metal chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione is 3-7. The method of claim 1, wherein the metal chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione is postemergence applied. The method of claim 1, wherein the metal chelate of 2- (substituted benzoyl) -1,3-cyclohexanedione is microencapsulated. The method of claim 1 wherein the intended crop is wheat. delete