DD160269A5 - HERBICIDES COMPOSITIONS - Google Patents

Abstract

The present invention relates to herbicidal compositions which contain as active ingredient substituted diphenyl ethers or a mixture of diphenyl ethers of the general formula in addition to at least one agriculturally permissible additive. The invention provides herbicidally highly effective means for selective weed control.

Description

Herbicidal compositions Field of application of the invention

This invention relates to herbicidal compositions containing substituted diphenyl ethers and to a method for controlling weeds with these herbicidal compositions.

Characteristic of the known technical solutions

There are no details of processes for the preparation of substituted diphenyl ethers known Ee are also no information on substituted diphenyl ether with herbicidal activity known.

Object of the invention

The aim of the invention is the ^one providing new funds with very good herbicidal activity for selective weed control ·

Considering the nature of the invention

The invention has for its object to find new compounds which are suitable as active ingredient in herbicidal compositions, and to provide processes for their preparation.

According to the invention, substituted diphenyl ethers are prepared which have the general formula

2 0KT. 1987 * 042 902

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0 0 GORCZR ¹

In this phrasing, the general symbols have the following meanings:

A is halogen or cyano,

X is hydrogen or halogen,

Y is hydrogen, halogen, cyano, trifluoromethyl or alkyl having 1 to 4 carbon atoms,

Z is oxygen or sulfur,

R is an alkylene or mono-substituted alkylene radical having from '1 to 3 carbon atoms, wherein the ^s ubstituent alkyl, oxoalkyl or hydroxyalkyl having 1 to 4 carbon atoms, and β

R ¹ is hydrogen or alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 8 carbon atoms, an ionic group, phenyl or mono-, di- or tri-substituted phenyl, the substituents being halogen, alkyl or alkoxy having 1 to 10 carbon atoms, cyanogen, Nitro or irifluoromethyl.

According to the invention, these substituted diphenyl ether are obtained by reacting

a) an appropriately substituted Benzoylhalogend, especially -Benzoylohlorid, ^m ^ a correspondingly substituted alcohol or a correspondingly substituted alpha-hydroxycarboxylic reacts or

b) reacting a correspondingly substituted benzoic acid with a correspondingly substituted alpha-halo-carboxylic acid ester »

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From the formula of the substituted diphenyl ether, it is readily apparent to those skilled in the art which substituents the benzoyl halides or the benzoic acid, which contribute the left part of the formula with the diphenyl radicals, and which substituents, the alcohols, alpha-hydroxycarboxylic acid esters or alpha-halocarboxylic acid esters, the right Form part of the formula, in order to obtain the desired substituted diphenyl ether.

Examples of halogens which are suitable in the general formula of the substituted diphenyl ether are bromine, chlorine, iodine or fluorine, bromine and chlorine being preferred. Some examples of alkyl and cycloalkyl radicals in this formula are methyl, ethyl, isobutyl, η Butyl, t-butyl, n-amyl, heptyl, octyl, iso-octyl, Honyl, decyl, cyclopropyl, cyclopentyl, cyclohexyl and cyclooctyl. Examples of suitable alkoxy, oxoalkyl and hydroxyalkyl groups are methoxy, ethoxy, butoxy, octoxy, oxoethyl, oxopropyl, oxobutyl, hydroxymethyl, hydroxyethyl, hydroxypropyl and hydroxybutyl. Examples of suitable alkylene groups are methylene, ethylene and propylene. The ionic groups should preferably be agricultural Examples of such compounds are alkali metal ions such as sodium, potassium or lithium, alkaline earth ions such as barium or calcium, ammonium ions or alkylammonium or alkanolammonium ions having from 1 to 4 carbon atoms.

Preferred compounds in the invention are those in which Z is oxygen, A is nitrogen, R ^{1 is} alkyl having up to 4 carbon atoms, X is hydrogen and Y is halogen.

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The compounds according to the invention exhibit a herbicidal activity. Some specific examples of preferred compounds are: 1 - (ethoxycarbonyl) ethyl-5 (2-chloro-4-trifluoromethylphenoxy) -2-bromobenzoate j 1 (Ethoxycarbonyl) ethyl-5- (2-chloro-4-trifluoromethylphenoxy) -2-cyanobenzoate; 1 '- (ethoxyo-carbonyl) ethyl-5- (2-chloro-6-bromo-4-trifluoromethylphenoxy) -2- oyanbenzoat ·

Of course, the substituted diphenyl ethers according to the formula given above also include the stereo and optical isomers in question «

For the preparation of the substituted diphenyl ether, it is possible to react appropriately substituted benzoyl halides with an alcohol or a correspondingly substituted alpha-hydroxycarboxylic acid ester or a correspondingly substituted benzoic acid with a correspondingly substituted alpha-halocarboxylic acid ester in accordance with generally known processes. The substituted benzoyl halides or benzoic acids and the substituted alpha- Hydroxy- or alpha-halogenated carboxylic acid esters are commercially available or can be prepared by known procedures. It is advantageous to add at least one stoichiometric amount of a substituted benzoyl halide with stirring to the substituted alpha-hydroxy carboxylic acid ester. Preferably, this reaction is carried out in the presence of an acid acceptor of an organic amine, ζ. Β. Triethylamine, pyridine or Εί, Ν-dimethylaniline · Since the reaction proceeds with evolution of heat, it is advantageous to add the substituted benzoyl halide in proportions such that the reaction mixture does not substantially exceed a temperature of about 35 ⁰ O. When the substituted diphenyl

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3 · 9.Θ2

ether prepared by reacting a substituted benzoic acid with an alpha-halocarboxylic acid ester, the ester is preferably in the presence of an azo compound such. B. 1,5-Diazoblcyclo- (5 "4.0) -undec-5-ene (DBU) performed. In any embodiment of the synthesis, it is possible to work in the presence of an inert solvent, such as, for example, in the presence of inert organic solvents, such as benzene, methylene chloride, chloroform, ethyl acetate or tetrahydrofuran. Upon completion of the addition of the substituted benzoyl halide to the alpha-hydroxycarboxylic acid ester (or at the completion of the addition of the alpha-halocarboxylic acid ester to the substituted benzoic acid), the reaction mixture is refluxed and boiled until the desired degree of conversion is achieved. The reaction mixture is then cooled to ambient temperature and is usually washed sequentially with dilute acid, dilute base and water to allow phase separation. The substituted diphenyl ether is isolated from the organic phase by known procedures, such as. B. by evaporation, crystallization or drying in vacuo. If desired, the substituted diphenyl ether may be further purified, e.g. B. by recrystallization.

Ausführungsbe! Game

The invention will be explained in more detail in the following examples,

example 1

1 '- (ethoxycarbonyl) ethyl-5- (2-chloro-4-trifluoromethylphenoxy) 2-bromobenzoate

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equipped with an addition funnel, a reflux condenser and a magnetic stirrer bar.

A 100 ml three-necked flask was charged with 1.18 g (0.01 mol) of ethyl acetate and 0.79 g (0.01 mol) of pyridine in 50 ml of methylene chloride. To dieaer solution at room temperature (about 20 ⁰ CJ) dropwise with stirring 2.07 g (0.005 mole) of 5- (2-0hlor-4-trifluoromethylphenoxy) -2-brombenzdylohlorld in 10 ml of methylene chloride · There was observed an exotherm , Upon completion of the addition, the reaction mixture was refluxed with stirring and held at boiling for 66 hours. The reaction mixture was then cooled, transferred to a separatory funnel and washed successively with 30 ml portions of 1N hydrochloric acid, water, 7% aqueous ammonium hydroxide and water. The washed organic phase was dried over magnesium sulfate and concentrated on a rotary evaporator at 55 ⁰ . There was obtained 2.2 g of a viscous yellow syrupy liquid which was identified as 1 '- (ethoxycarbonyl) ethyl-5- (2-chloro-4-trifluoromethylphenoxy) -2-bromobenzoate. The nuclear magnetic resonance data was as follows

NMR (Aoeton Dg) 7.0-8, O ₁ T (multiplet, 6H);

5.25 (Γ (quartet, 1H); 4.18 (t (doublet, 3H), 1.68 S (doublet, 3H); 1.18 J (T ^ iplett, 6H).

The substituted diphenyl ethers of the invention are effective agents for regulating the growth of a number of undesirable plants, especially weeds, when present in herbioidally effective amounts prior to germination of the weeds or weeds according to their growth medium

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Germs are added. The term "herbioidally-effective amount" refers to that amount of a compound or mixture of compounds required to sooth the weeds so that they can not recover after use of said agent. The amount of a specific compound or mixture of different compounds required to give a satisfactory herbicidal effect can vary widely and depends on a variety of factors, such as: Stubbornness of the particular weed species, degree of infestation by the weed, climatic conditions, soil conditions and mode of application of the weedkiller. As a rule, 0.22 to 11 kg of the herbicidal compound or mixture of herbicidal compounds per hectare are required. In individual cases, depending on the effectiveness of the particular compound, the effective amount can be determined in a well-known manner.

The compounds of the invention can be used as such or in formulations with agriculturally acceptable additives. Examples of such additives are inert carriers, other herbicides or compounds commonly used in agriculture, such as pestioids, stabilizers and fertilizers. Typically, the compounds are used as such or in Formulations in dust form or in the form of granules, wettable powders, solutions suspensions, aerosols, emulsions and dispersions applied. When the compounds according to the invention are formulated with other agriculturally acceptable additives, the proportion of the compounds or mixtures of the compounds according to the invention in such formulations may be within

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a wide range, for example between 0.05 to 95% by weight of the formulation, with 5 to 75% by weight being preferred

The compounds of the invention have been found to control the growth of a variety of broadleaf or grassy weeds at a dosage of 2.2 kg per hectare or less, both before and after germination of the weeds, with agriculturally desirable plants, such as maize, Wheat, rice and soybeans are not harmed. Examples of weeds whose growth can be controlled by the compounds according to the invention are: Brassica kaber, Setaria glauca, Digitaria eanguinalis, Sesbania spp. Abutilon theophrasti, Sorghum halepense, Echinochloa crusgalli, Datura stramonium, Sida spinosa, Ipomea prupurea (Roth) and the like.

Some of the compounds prepared according to Examples 1 to 12 were tested for herbicidal activity against certain weed species under controlled laboratory conditions of light, temperature and humidity. Selected seeds of such weeds were planted in shallow skins. For the pre-germination test, the shallow shells were treated with the selected compound immediately after planting. For the germination test, the shallow shells were treated with the selected compounds 2 weeks after the germination period. The compound was indicated as the solution in the flat shells Concentration sprayed on. The state of growth of the weeds was observed and the toxic effect of the compound was evaluated at intervals after its application.

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The following table summarizes the weed species and the compounds of Example 1 used. In this case, the compound was applied at a rate of 2.2 kg per hectare (2 pounds per acre).

Weed species Compound of Example 1

Sida spinosa

Datura stramonium X

Brassica kaber X

Setaria glauca

Digitaria sanguinalis Z

Sorghum halepense

Sesbania spp,

Abutilon theophrasti

Ipomea purpurea

Avena fatua

Echinochloa crusgalli

In the above table, the mark ¹¹ X "indicates that the specific compound was tested on the weed in question. All the tests showed that within 21 to 22 days after application the weeds were either destroyed or severely damaged it could not recover anymore »

It has been found that compounds according to the invention, in which the substituent z. As halogen and bromine in particular, as in Example 1, have a slightly better herbicidal activity in the application after germination than in the application before germination, if the dosage below about 5.5 kg per hectare, z. B. at 2.2 kg per hectare or lower.

Claims (7)

223 176 -10- 20.10,1982 57 963 18 Invention claim 1. Herbicidal compositions, characterized in that they contain a herbicidally effective amount of a substituted diphenyl ether or a mixture of diphenyl ethers, said diphenyl ether corresponding to the following formula 0 0 H it ι χ GORCZR ¹ where the general symbols have the following meaning: A is halogen or cyano, X is hydrogen or halogen, Y is hydrogen, halogen, cyano, trifluoromethyl or alkyl having 1 to 4 carbon atoms, Z is oxygen or soybean sulfur, R is an alkylene or monosubstituted alkylene radical having 1 to 3 carbon atoms, wherein the substituent is alkyl, oxoalkyl or hydroxyalkyl having 1 to 4 carbon atoms, and R ¹ is hydrogen or alkyl of 1 to 10 carbon atoms, cycloalkyl of 3 to 8 carbon atoms, an ionic group, phenyl or mono-, di- or trisubstituted phenyl, the substituents being halogen, alkyl or alkoxy having 1 to 10 carbon atoms, cyanogen, Nitro or trifluoromethyl, in addition to at least one agriculturally authorized additive, 9 ^ 176 - 11 - 57 963 18 2. Composition according to item 1, characterized in that in the formula of the active ingredient Z is oxygen. Composition according to item 1 or 2, characterized in that in the formula of the active ingredient R ^{1 is} an alkyl radical having up to 4 carbon atoms. « 09/03/82 4 · Composition according to one of the items 1 to 3 »characterized in that in the formula of the active ingredient A is halogen or cyano, 5. The composition according to item 1, characterized in that in the formula of the active ingredient Z is oxygen, R ^{1 is} an alkyl radical having up to 4 carbon atoms, X is hydrogen and Y is halogen, Composition according to item 1, characterized in that the active ingredient is 1 - (xthoxycarbonyl) ethyl-5- (2-chloro-4-trifluoromethylphenoxy) -2-bromobenzoate, A method of controlling weeds, characterized by contacting said weeds with a herblzid effective amount of a composition of item 1, wherein the herbicidal composition is contacted with the weed before or after germination.