CS232702B2 - Herbicide agent - Google Patents

Description

The present invention relates to a novel herbicidal composition suitable for controlling deaf oats and other grass and broadleaf weeds.

A large number of different hormonal and non-hormonal herbicidal compositions are generally used to control broadleaf weeds and undesirable grasses. Phenoxyacetates are generally used as herbicidal agents of the hormonal type for controlling broadleaf weeds. Phenylcarbamates, substituted ureas, substituted hydroxybenzonitriles, substituted symmetrical triazines, dinitrophenols, and polyhalocarboxylates are commonly used as non-hormonal herbicidal agents. Although the aforementioned compounds are well known and widely distributed on the market, these compounds exhibit little or no herbicidal activity against deaf oats, such as Avena fatua, Avena sterilis and Avena ludoviciana, when the compounds are applied post-emergence and at rates of application commonly used to control weeds in the presence of farm crops.

Examples of the most commonly used herbicides to control deaf oats include 4-chloro-2-butynyl-N- (3-chlorophenyl) carbamate and N-benzoyl-N- (3,42) ethyl ester

-dichlorophenyljalanine. However, it is not recommended to use these compounds in combination with other herbicides, since the other herbicides have an adverse effect on the above two compounds, in that the compounds lose virtually all herbicidal activity against deaf oats in the presence of said herbicides.

For example, it is known that by applying N-benzoyl-N- (3,4-dichlorophenyl) alanine ethyl ester alone at an amount of 1.12 kg / ha, 70% deaf oat control efficiency (fourth leaf stage) is achieved. N-benzoyl-N- (3,4-dichlorophenyl) alanine at the same rate of 1.12 kg / ha, but mixed with 2,4-dichlorophenoxyacetic acid at 0.42 or 0.84 kg / ha, the deaf oat killing efficiency decreases 29% and 25%, respectively, when 0.14 and 0.28 kg / ha of 2-methoxy-3,6-dichloro-benzoic acid are added to N-benzoyl-N- (3,4-dichlorophenyl) alanine ethyl ester. and 0.28 or 0.56 kg / ha of 3,5-dibromo-4-hydroxybenzonitrile, then deaf oat killing efficiency is reduced to 29%, 24%, 53% and 53%, respectively.

It is already known that 1,2-dialkyl-3,5-diphenylpyrazolium salts are suitable for the selective control of deaf oats.

It has now been found that 1,2-dialkyl-3,5-diphenyl, pyrazolium salt-based herbicides for controlling deaf oats can be used in combination with herbicides for controlling broadleaf weeds and grasses without losing the ability to selectively control deaf oats. as far as the pyrazolium compound is concerned, and the loss of the herbicide's ability to control broad-

in which

R 1 represents a methyl group,

R2 represents an alkyl group having a total number of carbon atoms of 1 to 4,

Y, Y ‘, Z and Z‘, which may be the same or different, represent a halogen atom, a hydrogen atom, a methyl group or a methoxy group,

X is an anion having a charge of 1 to 3, and m is an integer of 1, 2 or 3, provided that only one phenyl ring can be substituted on the carbon at para to the pyrazolium ring by a substituent other than a hydrogen atom, and a phenoxyacetate compound of formula VII

in which

R3 represents a chlorine atom or a methyl group,

R1 represents a hydrogen atom or a methyl group,

R 5 represents a group -ORe or -OM, where

Re represents a hydrogen atom, an alkyl group having a total carbon number of up to 8, preferably a methyl group, an ethyl group, an isopropyl group, a butyl group, a pentyl group, an ethylhexyl group, an octyl group or an isooctyl group, an alkoxyalkyl group having a total carbon number of up to 8 , preferably butoxyethyl or 2-butoxyethyl, and tetrahydrofurfuryl and

M represents a group

R7

HN + —Rs

R9 leafy weeds and undesirable grasses effectively suppress the growth of the plants to be controlled.

SUMMARY OF THE INVENTION The present invention provides a herbicidal composition for controlling deaf oats and broadleaf weeds comprising a 1, 2-dialkyl-3,5-diphenylpyrazolium compound of the formula I or HN + (H j ' _{: 1-} (R 10 OH) _n , wherein

R 2, R 5 and R 9 are hydrogen or alkyl having a total number of carbon atoms of 1 to 4,

R 10 represents an alkylene group having a total number of carbon atoms of 1 to 4, n represents an integer of 0, 1 or 2 and n 'represents an integer of 1, 2 or 3, the sum of nan' being 3, and optionally from conventional herbicidal additives, the weight of the pyrazolium compound, calculated on the weight of the pyrazolium cation, on the weight of the phenoxyacetate compound, calculated on the weight of the phenoxyacetic acid, is 1: 4 to 16: 1.

Preferably, the herbicidal composition according to the invention comprises, as a compound of formula I, 1,2-dimethyl-3,5-diphenylpyrazolium methyl sulfate or 1,2-dimethyl-3,5-diphenylpyrazolium chloride, respectively.

As the compounds of the formula, the herbicidal composition according to the invention preferably comprises the dimethylamime salt of 2,4-dichlorophenoxyacetic acid.

In the general formula I, suitable halogen substituents in the meaning of the general substituents Y, Y‘, Z and Z‘ include fluorine, chlorine, bromine and iodine. However, preferred halogen substituents are chlorine, fluorine and bromine.

As examples of suitable anions. the substituent X in formula (I) includes halides such as chlorides, bromides or iodides, acetate, sulfate, hydroxide, hydrogensulfate, methylsulfate, benzenesulfonate, C 1 -C 1 -alkoxyhenzenesulfonate, C 1 -C 3 -alkylhesulfonate preferably toluenesulfonate, such as, for example, p-toluenesulfonate, nitrate, carbonate, bicarbonate, C 1 -C 10 -alkanesulphonate, chlorate, perchlorate, tricycles, Brs. ^{- _} and J3.

Said herbicidal compositions may be prepared either by mixing said herbicides in the form of pure compounds, or together with diluents or carriers such as. this is the case with mixed herbicidal formulations.

Controlling deaf oats and broadleaf weeds and grasses beyond. The use of the herbicidal pro232702 composition according to the invention is carried out by application to the foliage of the plants to be controlled, preferably using herbicidally active substances, dissolved or dispersed in solid or liquid diluents or carriers, for example in water. The water-soluble salts of pyrazolium herbicides for controlling deaf oats and wettable powders, applied liquids or for controlling broadleaf weeds or grasses are usually dispersed in water and thus applied to the leaves of undesirable plants. Typically, surfactant, spray and adhesive aids and the like are added to the composition to improve leaf and stem penetration.

Typically, 0.1 to 5%, preferably 0.5 to 3%, of a surfactant is added to the solution or dispersion, and nonionic, anionic, cationic and / or nonionic-aionic surfactants may be used as surfactants. reagents. Examples of preferred surfactants include alkylaryl polyglycol ethers, alkylphenol ethoxylates, trimethylnonylpolyethylene glycol ether, nonylphenol-ethylene oxide condensate, alkylphenol-ethylene oxide condensate, alkylpolyoxyethylene ethers, polyoxyethylene sorbitan monolaurate, octylphenoxy-dimethylaminopropoxyethoxy-dimethylaminopropoxyethoxyimethoxide-dimethylaminopolyethoxyethoxymethoxide. Preferred nonionic surfactants are those surfactants whose hydrophilic-lipophilic balance is 11-16.

The pyrazolium salts and phenoxyacetate compounds may be individually prepared as wettable powders, emulsifiable concentrates or the like and mixed with each other even in a field spray tank.

The application of the herbicidal compositions according to the invention is carried out using conventional equipment and conventional application techniques.

The herbicidal compositions according to the invention are not only suitable for controlling deaf oats and broadleaf weeds or grass weeds themselves, but can also be used in the presence of certain crops such as wheat, barley, rye, flax, peas, sugar beet, rape or sunflower.

The herbicidal compositions of the invention are applied in an amount that the user finds effective against the undesirable plant, taking into account the type of environment, the growth stage of the undesired plant, the type of formulation and the like.

The herbicidal compositions containing the 1,2-dialkyl-3,5-difemylpyrazolium salt and the chlorophenoxyacetic acid or ester or salt or salts of pyrazolium cation and halofemoxyacetate anion are usually dispersed in water and applied as an aqueous spray to the leaves of undesirable plants. The water-soluble salts of the pyrazolium compound and the halophenoxyacetate compound can be dissolved in water and thus applied to the leaves of undesirable plants. If desired, a surfactant, spray or adhesive and the like can also be added to the solution, and it is generally preferred to add linear alkyl polyoxyethylene ether to the mixture as surfactant. The pyrazolium salts and phenoxyacetate compounds may also be prepared individually as wettable powders, emulsifiable concentrates, water-miscible concentrates, or the like, and as such blended in a field spray tank. Of course, any commercially available phenoxyacetic acid formulation or ester or salt thereof may be used. Typical ester formulations that may be used are:

1.

% by weight of 2,4-dichlorophenoxy acetic acid 2-ethyl ester,% by weight of kerosene and 5% by weight of a mixture of oil-soluble sulfates with polyoxyethylene ethers;

2.

% by weight of butyl 2,4-dichlorophenoxyacetic acid,% by weight of xylene and% by weight of a mixture of oil-soluble sulfates with polyoxyethylene ethers;

3.

% by weight of 2,4-dichlorophenoxyacetic acid isopropyl ester,% by weight of heavy aromatic solvent and% by weight of linear alkyl polyoxyethylene ether.

Typical wettable powders based on pyrazolium salt and halophenoxyacetic acid or ester or salt thereof contain about 25 to 75% by weight of the active compound, 20 to 71.5% by weight of a finely divided carrier such as attapulgite, kaolin or silica, 1.5 to 3%. by weight of a surfactant such as sodium isothionate sodium-N-methyl-N-oleoyltaurate ester or alkylphenoxypolyoxyethylenethanol, and 2-3% by weight of a dispersing agent such as high purity sodium lignin sulphate or naphthalenesulphonic acid.

For effective control of undesirable plants, these herbicidal compositions are normally applied in a sufficient amount to provide 0.28 to 2.24 kg / ha, preferably 0.56 to 1.12 kg / ha, pyrazolium cation and 0.145 to 1.12 kg / ha. ha, preferably 0.28 to 0.56 kg / ha, of phenoxyacetic acid or an ester or salt thereof, calculated per acid.

While these are: herbicidal compositions suitable for controlling deaf oats and broadleaf weeds in the presence of agriculturally important crops such as wheat and barley, they are also useful for controlling said undesirable plant species in the presence of rye, flax and peas.

The invention is explained in more detail below with reference to several exemplary embodiments. In these examples, all parts and percentages are by weight and percentages by weight.

Example 1

In the test, which is evaluated in Table I, see deaf oats (Avena fatua) grown in a greenhouse up to four leaf stage. The oats are then sprayed with an aqueous solution containing a sufficient amount of the test compound to provide a concentration of about 0.168 to 0.67 kg / ha of pyrazolium cations. For comparison, test compounds are used alone and in combination with 4-chloro-2-methylphenoxyacetic acid, added in sufficient quantity to achieve a concentration of 0.2.8 kg / ha of said compound.

All test solutions are prepared in such a way that they contain about 0.1% by weight of a biodegradable nonionic linear alkyl polyoxyethylene ether surfactant. Untreated plants were used as controls, and all foliage was harvested and weighed four weeks after application.

The results obtained are summarized in Table I below. From this table it can be seen that the addition of 4'-chloro-2-methylphenyloxyacetic acid to solutions containing 1,2-dialkyl-3,5-diphenylpyrazolium salt, it significantly improves the control of deaf oats. Adding 4-chloro-2-methylphenoxyacetic acid to a commercially available herbicide to control deaf oats such as 4-chloro-2-butynyl N- (3-chlorophenyl) carbamate (which is not within the scope of the invention) annul.

TABLE I

Effect of 4-chloro-2-methylphenoxyacetic acid on deaf oats activity of test compounds

Application Dose Inhibition of deaf oat foliage growth (%) (kg / ha) no acid added. 44-chloro-2-methylphenoxy-chloro-2-methylphenoxyacetic acid

0.28 kg / ha **

Water 0 0 1,2-dimethyl-3,5-diphenylpyrazo- liumtoluenesulfonate 0,16 * 45 62 1,2-dimethyl-3,5-diphenylpyrazo- liumtoluenesulfonate 0,33 * 53 73 1,2-dimethyl-3,5-difemylpyrazole chloride 0,67 * 53 69 4-chloro-2-butynyl N- (3-chlorophenyl) carbamate 0.56 59 0

*) Based on pyrazolium cation **) The acid is applied as a dimethylamine salt, the amounts quoted are calculated on the amount of acid

Example 2

Control of deaf oats in the presence of Waldron wheat

In this test, Waldron's wheat is sown in early May. After five days and a few days before the emergence of wheat, deaf oats (Avena spp.) Arise. When deaf oats rise to the four-leaf stage, selected plots are sprayed with aqueous solutions containing 1,2-dimethyl-3,5-diphenylpyrazoliummes with respect to the control effectiveness of deaf oats and white mustard. The results obtained are summarized in Table II below. ethylsulfate or said compound and 2,4-dichlorophenoxyacetic acid.

The application rates are chosen to achieve a concentration of 0.56 or 1.12 kg / ha of active pyrazolium cations alone and in combination with 0.42 kg / ha of 2,4-dichlorophenoxyacetic acid.

Each solution also contains 0.5% by weight of a linear alkyl polyoxyethylene ether surfactant. Eight. weeks after application, the plots are evaluated, 232 70 2

TABLE II

Control of deaf oats and white mustard in the presence of Waldron wheat

Application Dose Inhibition (0–100) in% (kg / ha) Deaf White Walron Oats Mustard Wheat

1,2-dimethyl-3,5-diphenylpyrazo- 0,56 * 61 0 1 liummethylsulfate 1,12 * 78 10 3 1,2-dimethyl-3,5-diphenylpyrazo- 0.56 * + 0.42 ** liummethylsulfate 2,4-dichloro- phenoxyacetic 87 100 ALIGN! 3 1,2-dimethyl-3,5-diphenylpyrazo- 1.12 * + 0.56 ** liummethylsulfate 2,4-dichloro- phenoxyacetic 87 100 ALIGN! 3 Untreated samples 0 0 0

*) Based on pyrazolium cation.

The acid is applied as the dimethylammonium salt, the amounts shown being converted to the amount of acid.

Example. 3

Preparation of 1,2-dimethyl-3,5-diphenylpyrazolium-2,4-dichlorophenoxyacetate The 1,2-dimethyl-3,5-diphenylpyrazolium methylsulfate was converted by ion-exchange chromatography to pyrazolium hydroxide. The aqueous pyrazolium hydroxide solution is then titrated with 2,4-dichlorophenoxyacetic acid. After a very short time thereafter, the added 2,4-dichlorophenoxyacetic acid goes into solution. Value. pH. The pH of the solution is controlled by a pH meter. The acid addition is stopped when the pH is 7. The original pH is 12-13. The aqueous solution is then maintained at ambient temperature for 48 hours. The pH of the solution is then approximately. 8. Next, add an additional amount of acid until pH is again reached

2.4 hours. (pH is maintained at 7), the aqueous solution is evaporated to give a yellow oil which is dried by forming and then evaporating the azeotrope using the same. volumes, toluene, and anhydrous acetone, which is repeated several times. Hexane with 5-10% anhydrous acetone was then added. The oil solidified to a white solid, which was filtered off. Wash with hexane / acetone and dry. 7 g of a lemon-yellow solid are obtained, m.p. 152-154 ° C.

Calcd for N2O3Cl2C25H22:

% C, 63.97;% H, 4.72;% N, 5.96.

% H, 4.67;% N, 5.90

This compound is useful as a herbicide.

Example 4

Preparation of 1,2-Dimethyl-3,5-diphenylpyrazolium-4 - (1,1'10- [2-methylphenoxyacetate] 1,2-dimethyl-3,5-diphenylpyrazolium hydroxide in aqueous solution Titrate with 4-chloro-2-methylphenoxyacetic acid to pH 7, which is maintained for 48 hours, then slowly dissolve the 4-chloro-2-methylphenoxyacetic acid added as a solid and evaporate the aqueous solution. After addition of toluene / acetone several times azeotropically distilled several times after addition of hexane (5% acetone) the oil solidified to a pale yellow solid which was filtered off, washed with hexane and dried to give 6, 5 g of a light yellow solid, m.p. 138-140 ^° C.

Pro, NzQsG U.-ilDs calculated:

69.55% C, 5.61% H, 6.24% N, found:

68.47% C, 5.86% II, 6.42% N.

This compound is useful as a herbicide.

Claims (4)

A herbicidal composition for controlling deaf oats and broadleaf weeds, characterized in that it consists of a 1,2-dialkyl-3,5-diphenylpyrazolium compound of the general formula I. IT. clay) in which R1 is methyl, R 5 represents an alkyl group having a total number of carbon atoms of 1 to 4, Y, Y ‘, Z and Z *, which may be the same or different, represent a halogen atom, a hydrogen atom, a methyl group or a methoxy group, X is an anion having a charge of from 1 to 3 and m is an integer of 1, 2 or 3, provided that only one phenyl ring can be substituted on the carbon at para to the pyrazolium ring by a substituent other than a hydrogen atom , and a phenoxyacetate compound of formula (VII) (VII) wherein: R3 represents a chlorine atom or a methyl group, R4 represents a hydrogen atom or a methyl group, R 5 is -OR 6 or -OM, wherein R 6 is hydrogen, alkyl having a total number of carbon atoms of 1 to 8, preferably methyl, ethyl, isopropyl, butyl, pentyl, ethylhexyl, octyl or isooctyl an alkoxyalkyl group having a total carbon number of 2 to 8, preferably a butoxyethyl or 2-butoxyethyl group, and a tetrahydrofurfuryl group, and M represents a group R7 AND HN + —Re R 9 or HN + (H) - (R 10 OH) _n where R 7, R 8 and R 9 represent a hydrogen atom or an alkyl group having a total number of carbon atoms of 1 to 4, R 10 is an alkylene group having a total number of carbon atoms of 1 to 4, n is an integer of 0, 1 or -2 and n is an integer of 1, 2 or 3, the sum of nan 'being 3, and optionally from conventional herbicidal additives, wherein the ratio of the weight of the pyrazolium compound, calculated on the weight of the pyrazolium catholt, to the weight of the phenoxyacetate compound, calculated on the weight of the phenoxyacetic acid, is 1: 4 to 16: 1. 2. The herbicidal composition of claim 1, wherein the compound of formula I is 1,2-dimethyl-3,5-diphenylpyrazolium methyl sulfate. 3. A composition according to claim 2, wherein the compound of formula (VII) is a dimethylamine salt of 2,4-dichlorophenoxyacetic acid. 4. A composition according to claim 1, wherein the compound of formula (I) is 1,2-dimethyl-3,5-diphenylpyrazolium chloride.