GB2106102A - Herbicidal compounds derived from aryloxybenzoic acids - Google Patents

Abstract

New herbicides especially useful against weeds in cereals or soya, have the formula: <IMAGE> in which: X1, X2 and X3 represent a halogen atom, such as fluorine, chlorine or bromine; a polyhalogenoalkyl radical; NO2; CN; an alkyl radical; an SO2-alkyl radical; SO2NH2; NO; or COO-alkyl, Y1 is -N= or -CH=, Y2 is -N= or, when Y1 is -CH=, a group CX7=; Y3 is the oxygen or sulphur atom; X4 is the hydrogen atom or a substituted or unsubstituted alkyl radical; X5 is the hydrogen atom; an alkali metal atom; a cationic quaternary or non-quaternary ammonium group; a substituted or unsubstituted alkyl radical; or a halogen atom; X6 is a substituted or unsubstituted alkyl radical, or an aryl radical, in particular a phenyl radical, which is substituted or unsubstituted; and X7 is the hydrogen atom or a halogen atom.

Description

SPECIFICATION Herbicidal compounds derived from phenoxybenzoic acids The present invention relates to certain phenoxy-benzoic acid derivatives containing sulphonamide groups, which are useful as herbicides and in particular as herbicides for the weeds present in soya crops.

Herbicides derived from phenoxybenzoic acids and their esters are widely known, in particular from U.S. Patents 3,652,645, 3,784,635, 3,798,276, 3,873,302, 3,907,866, 3,928,416, 3,983,168 and 4,063,929 and European Patent Applications Nos. 3,416 and 23,392.

The present invention relates to phenoxybenzoic acid derivatives containing sulphonamide groups, of the formula:

in which X, X2 and X3, which may be the same or different, each represent a halogen atom, such as fluorine, chlorine or bromine; a polyhalogenoalkyl radical, preferably having from 1 to 4 carbon atoms, especially CF3; NO2; CN; an alkyl radical, preferably having from 1 to 4 carbon atoms; an SO2-alkyl radical, preferably having from 1 to 4 carbon atoms; SO2NH2; NO; or COOalkyl, the alkyl part preferably having from 1 to 4 carbon atoms, Y, is -N = or -CH =; Y2 is -N = or, when Y, is -CH =, a group -CX7 =; V3 is the oxygen or sulphur atom; X4 is the hydrogen atom or an alkyl radical, preferably having from 1 to 4 carbon atoms, which is unsubstituted or substituted, in particular by halogen atoms;X5 is the hydrogen atom; an alkali metal atom, in particular a sodium or potassium atom; a cationic quaternary or non quaternary ammonium group; an alky radical preferably having from 1 to 4 carbon atoms, which is unsubstituted or substituted, in particular by halogen atoms; or a halogen atom, in particular a chlorine atom; X8 is a substituted or unsubstituted alkyl radical preferably having 1 to 4 carbon atoms, or an aryl radical, in particular a phenyl radical, which is substituted or unsubstituted; suitable substituents on alkyl or aryl, in particular phenyl, radicals represented by X6 include one or more halogen atoms or alkyl, amino, cyano, nitro, alkoxy, hydroxy, formyl and mercapto groups (alkyl and alkoxy groups preferably containing 1 to 4 carbon atoms); and X7 is the hydrogen atom or a halogen atom.

Compounds of formula I in which X, is CF3, X2 is C1, X3 is C1 or NO2, X5 is H, Na, C1 or methyl and Y, andY2 are -CH = are preferred: compounds in which X, is CF3, X2 is C1, X3 is NO2, X5 is H, Na or Me and Y, and V2 are -CH = are particularly preferred. The symbol V3 preferably represents the oxygen atom; the symbol Xe preferably represents an unsubstituted alkyl group containing 1 to 4 carbon atoms (e.g. methyl) or a phenyl group substituted by an alkyl group containing 1 to 4 carbon atoms (e.g. methyl).

The processes for the preparation of the products of the formula (I) also form part of the invention.

In a first process, an acid chloride of the formula

is reacted with a sulphonamide of the formula: X6-SO2-NH-X5 (Ill) in which formulae the various symbols are as hereinbefore defined.

The reaction is advantageously carried out at from 50 to 150"C, preferably at from 80 to 110"C, in a solvent, such as a halogenated or non-halogenated aliphatic or aromatic hydrocarbon; the concentration of products of the formulae (II) and (I) is generally from 1 to 80%, preferably from 10 to 30%. The presence of an acid acceptor, such as a tertiary amine, in particular triethylamine or pyridine, is also preferred.

In the process which has just been described, in which the products of the formulae (II) and (III) are reacted, Xe is preferably not a halogen atom. The compounds of the formula (I) in which Xe is a halogen, preferably chlorine, atom are generally prepared by reacting a hypohalite, preferably an alkali metal, e.g. sodium, hypohalite with the corresponding product of formula (l) in which Xe is the hydrogen atom. This reaction is generally carried out in an aqueous medium at a pH of more than 10, preferably of more than 11.5, and at a temperature of from 0 to 50'C.

The acid chloride of the formula (II) is usually obtained by reacting Soy12 with the corresponding acid of the formula:

The acid of the formula (IV) and the sulphonamide of the formula (III) can be prepared by known methods.

In a second process for the preparation of products according to the invention in which Xe is a hydrogen atom, an acid of the formula (IV) is reacted with an isocyanate of the formula X6-SO2-N = C = O, in which formulae the various symbols have the meanings already given for the formula (I); this reaction is advantageously carried out in a solvent medium, preferably in the presence of a catalytic amount of organic base; the temperature is generally from 20 to 100"C, preferably from 40 to 80"C; the concentration of products of the formulae (IV) and (I) is generally from 5 to 70% by weight.

As solvents which can be used, there may be mentioned optionally halogenated aliphatic or aromatic solvents, such as benzene, toluene and xylene.

As the organic base, there may be mentioned para-(dimethylamino)-pyridine.

The isocyanates of the formula (V) can be prepared by known methods.

The first process of preparation according to the invention, using the reactant of the formula (III), is preferred if Xe is an aliphatic group, and the second process, using an isocyanate of the formula (V), is preferred if Xe is an aromatic group.

The conversion of products of the formula (I) in which X5 is the hydrogen atom to the corresponding products in which Xe is an alkali metal atom can be carried out by known methods, in particular in accordance with the processes applicable to the known phenoxybenzoic acid derivatives containing sulphonamide groups.

In this specification, unless otherwise specified, percentages are by weight. By the expression "known methods" as used in this specification is meant methods heretofore used or described in the chemical literature.

The following Examples illustrate the invention.

Example 1: 1 -(1 -Carboxyethyl) 5-[2-chIorn-4rifluoromethyl-phenoxy]-2-nitrobenzoate (3 g; 6.9 millimols) is dissolved in toluene (15 ml) containing thionyl chloride (2 g).

The solution is heated at the boil under reflux for 4 hours and then cooled. The solvent and the excess thionyl chloride are removed by distillation under reduced pressure. The residue is taken up in tetrahydrofuran (25 cc). Methanesulphonamide (CH3SO2NH2) (0.9 g) and a catalytic amount of para-(dimethylamino)-pyridine (about 5 mg) are added. A solution (10 ml) of triethylamine (0.77 g) in anhydrous tetrahydrofuran is also added dropwise. After the addition, the stirring is continued for 2 hours, further tetrahydrofuran (50 ml) is added and the solution is washed with a 5% strength by weight aqueous solution of hydrochloric acid (2 x 25 ml) and then with brine. It is dried over MgSO4 and filtered and the solvent is removed by distillation under reduced pressure.

The residue is purified by liquid chromatography on a silica column (eluent: 10% strength acetic acid in CHCl3).

The product of the formula;

is obtained (0.5 g).

Example 2 A solution (150 ml) of para-toluenesulphonyl isocyanate (50 g; 261 millimols) in toluene is added dropwise, and with stirring, to a toluene solution (350 ml) containing carboxymethyl 5 [2-ch lorn-4-(trifluorn-methyl)-phenoxy-2-nitrnbenzoate (100 g; 239 millimols) and also a catalytic amount of para-(dimethylamino)-pyridine (about 5 mg).

After the addition, the mixture is heated at the boil under reflux for 6 hours. It is cooled and the solvent is drive off by distillation under reduced pressure; this gives a crude product, which is recrystallised from a toluene/hexane mixture.

(4-Methylphenyl)-sulphonylaminocarbonylmethyl 5-[2-chloro-4-(trifluoromethyl)-phenoxy-2-ni- trobenzoate of the formula:

is thus obtained (115 mg; 209 millimols).

This product melts at about 130"C and has infra-red absorption bands (in KBr) at 3,205, 1,705 and 1,580cm1. In the NMR spectrum (nuclear magnetic resonance; measurement carried out in hexadeuterated acetone; chemical shift delta expressed in ppm relative to the tetramethylsilane standard), peaks are observed at 2.35 ppm (singlet for 3 protons), 5 ppm (singlet for 2 protons) and 7.3 to 8.5 ppm (multiplet for 10 protons).

Example 3: The sodium salt of the product of Example 2 (N-Na group) is obtained by reacting the latter with sodium hydride in anhydrous tetrahydrofuran; the solvent is then removed by distillation in vacuo. In the infra-red spectrum, absorption bands are observed at 1,600 and 1,735 cm-'.

Example 3 (A) The procedure followed is the same as in Example 3, but the product of Example 1 is used and its sodium salt (N-Na group) is thus obtained.

Example 4: The procedure of Example 2 is followed, but 1-(1-carboxyethyl) 5-[2-chloro-4-(trifluoromethyl)- phenoxy]-2-nitrobenzoate is reacted with para-toluenesulphonyl iso-cyanate.

The product of the formula:

is obtained (0.3 g).

In the infra-red spectrum, an absorption band is observed at 1,690 cm-', and in the NMR spectrum, the following chemical shifts (expressed in ppm) are observed; 1.42 (doublet corresponding to 3 protons; coupling constant = 14 Hz).

2.4 (singlet corresponding to 3 protons), 5.24 (quadruplet corresponding to one proton; coupling constant = 1 4 Hz).

7.2 to 8.2 (multiplet corresponding to 10 protons).

Example 5: Example 1 is repeated, but carboxymethyl 5-[2-chloro-4-trifluoromethylphenoxy]-2-n itrobenzoate is used as the starting reactant.

An oil consisting of the product of the formula:

is obtained (1 g). This formula is confirmed by the IR and NMR spectra.

Example 6: Example 5 is repeated, but the methanesulphonamide is replaced by CH3-SO2-NH-CH3. The heating is continued for 89 hours. An oil consisting of the product of the formula:

is obtained (3 g). This formula is confirmed by the IR and NMR spectra.

Example 7: Species of crops and weeds are placed in 1 0 cm rows in 20 cm x 25 cm dishes containing earth.

The species used are indicated in Table (I).

Cotton, maize (field corn), soya and xanthium are sown at a rate of 4 to 5 seeds per row.

The smaller species [abutilon, wiid mustard, amaranth, foxtail millet and green panic grass (Setaria viridis)] are sown without counting the seeds, but in a number which is nevertheless sufficient subsequently to form a dense line of plantlets.

The initial watering, up to the emergence period, is carried out from above the earth covering the seeds.

The pre-emergence treatment is carried out less than one day after sowing.

The desired stage of development for the post-emergence treatment of cotton, soya, xanthium, abutilon, wild mustard and chenopodium is the stage of one true leaf or a first trifoliate leaf. For maize, the desired stage is a height of 7.5 to 10 cm, whereas for the graminaceous plants, the desired stage is a height of 2.5 cm.

The compositions of the invention are applied by spraying under a pressure of 2.5 bars (= 36 psi) at a rate of 375 1 /ha (= 40 gallons/acre). The spraying compositions consisted of a mixture, in respective proportions by volume, of water (20 cc) and 0.1 % of a surface-active agent (a mixture of alkali metal salts of condensates of ethylene oxide with alkyl(C6-C16)- benzena-sulphonic acids).

After treatment, irrigation is carried out by sub-irrigation in the case of the plantlets which have already emerged, and by watering from above in the case of the seeds which have not yet produced plantlets.

2 weeks after treatment, the activity measurements are carried out according to a scale from 0 to 100%. In the case of the weeds, this measurement indicates the level of destruction; in the case of the crops, this measurement indicates the degree of attack or degree of phytotoxicity, the grade zero being assigned to plants in the same condition as the control, and the grade one hundred being assigned to complete destruction.

As regards the application doses, the correspondance between metric and U.S. units is as follows: pounds/acre 10 4 2 1 0.5 0.25 0.125 0.0625 kg/ha 11.2 4.48 2.24 1.12 0.56 0.28 0.14 0.07 Table (II) gives the results obtained with the compounds of Examples 1 to 6.

Example 8: Herbicidal application in the pre-emergence treatment of plant species.

A number of seeds are sown in 9 x 9 x > < 9 cm pots filled with light agricultural earth, this number being determined as a function of the plant species and the size of the seed.

The seeds are then covered with an approximately 3 mm thick layer of earth.

After moistening the earth, the pots are treated by spraying with an amount of spraying mixture which corresponds to a volumetric application dose of 500 1 /ha and contains the active ingredient at the desired concentration.

The spraying mixture was prepared by diluting an emulsifiable concentrate, which itself consisted of: active ingredient (5 g) xylene (83 g) 10:1 ethylene oxide/nonylphenol condensate (8 g) calcium dodecylbenzenesulphonate (4 g).

According to the concentration of active ingredient in the spraying mixture, the dose of active ingredient applied was 0.25 to 2 kg/ha.

The treated pots are then placed in troughs which are intended to receive the moistening water, for sub-irrigation, and are kept for 21 days at a temperature of 22-24"C and under 70% relative humidity.

After 21 days, the number of living plants in the pots treated with the spraying mixture containing the active ingredient to be tested, and the number of living plants in a control pot treated under the same conditions, but by means of a spraying mixture not containing active ingredient, are counted. The percentage destruction of the treated plants, relative to the untreated control, is thus determined. A percentage destruction equal to 100% indicates that there has been complete destruction of the plant species in question, and a percentage of 0% indicates that the number of living plants in the treated pot is identical to that in the control pot.

Example 9: Herbicidal application in the post-emergence treatment of plant species A number of seeds are sown in 9 x 9 X 9 cm pots filled with light agricultural earth, this number being determined as a function of the plant species and the size of the seed.

The seeds are then covered with an approximately 3 mm thick layer of earth and the seed is left to germinate until it has produced a plantlet of 5 to 10 cm in height.

The pots are then treated by spraying with an amount of spraying mixture which corresponds to a volumetric application dose of 500 1 /ha and contains the active ingredient at the desired concentration.

The spraying mixture was prepared in the same manner as in Example 8.

According to the concentration of active ingredient in the spraying mixture, the dose of active ingredient applied was 0.125 to 1 kg/ha.

The treated pots are then placed in a greenhouse in troughs which are intended to receive the moistening water, for sub-irrigation, and are kept for 14 days at a temperature of 22-24"C and under 70% relative humidity.

After 14 days, the number of living plants in the pots treated with the spraying mixture containing the active ingredient to be tested, and the number of living plants in a control pot treated under the same conditions, but by means of a spraying mixture not containing active ingredient, are counted. The percentage destruction of the treated plants, relative to the untreated control, is thus determined. A percentage destruction equal to 100% indicates that there has been complete destruction of the plant species in question, and a percentage of 0% indicates that the number of living plants in the treated pot is identical to that in the control pot.

The results of Examples 8 and 9 are indicated in Tables (III) and (IV).

Each of these Tables (III) and (IV) comprises, on the one hand, pre-emergence results obtained in accordance with Example 8, and, on the other hand, post-emergence results obtained in accordance with Example 9.

Table (III) gives results obtained with the active ingredient of Example 2.

Table (IV) gives results obtained with the active ingredient of Example 5.

The experiments carried out therefore show the notably advantageous properties of the compounds according to the invention, for both the pre-emergence and post-emergence treatment of crops, and more particularly of soya and cereals (including maize).

In case of soya, the activity of the compounds is particularly advantageous if this crop is infested with dicotyledon weeds such as abutilon, xanthium, ipomea and polygonum. In the case of cereals, the activity of the compounds is particularly advantageous if these crops are infested with dicotyledon weeds such as chenopodium, amaranth, ambrosia, polygonum, chrysanthemum, mustard and particularly stellaria and yellow bedstraw.

For their use in practice, the compounds according to the invention are rarely employed by themselves. Most frequently, these compounds form part of compositions. The present invention provides herbicidal compositions which comprise, as active ingredient, a compound of formula (I) in association with a herbicidally acceptable carrier. The carrier may be solid or liquid. The compositions may also comprise a herbicidally acceptable surface-active agent. In particular, the customary inert carriers and the customary surface-active agents can be used. These compositions also form part of the invention.

These compositions can also contain various kinds of other ingredients, such as e.g. protective colloids, adhesives, thickeners, thixotropic agents, penetrating agents, stabilisers, and sequestering agents, and also other known active ingredients have pesticidal properties (in particular insecticidal, fungicidal or herbicidal properties), properties promoting plant growth (in particular fertilisers) or properties regulating plant growth. More generally, the compounds used in the invention can be combined with any of the solid or liquid additives corresponding to the usual formulation techniques.

The use doses of the compounds of the invention can vary within wide limits, in particular according to the nature of the adventitious plants to be removed and the usual degree of infestation of the crops by these adventitious plants.

In general, the compositions according to the invention usually contain from 0.05 to about 95% (by weight) of active ingredient: such compositions generally contain from 1 % to about 95% of one or more solid or liquid carriers and, if appropriate, from 0.1 to about 20% of one or more surface-active agents.

According to what has already been stated, the compounds, used in the invention are generally combined with carriers and, if appropriate, surface-active agents.

In the present account, the term "carrier" denotes an organic or inorganic, natural or synthetic material with which the active ingredient is combined in order to facilitate its application to the plant, or to the soil. This carrier is therefore generally inert and it must be acceptable in agriculture, in particular on the plant treated.The carrier can be solid (e.g. clays, natural or synthetic silicates, silica, resins, waxes, and solid fertilisers) or liquid (e.g. water, alcohols, in particular butanol, esters, in particular methylgycol acetate, ketones, in particular cyclohexanone and isophorone, petroleum fractions, aromatic hydrocarbons, in particular xylenes, or paraffinic hydrocarbons, aliphatic chlorohydrocarbons, in particular trichloroethane, or aromatic chlorohydrocarbons, in particular chlorobenzenes, water-soluble solvents, such as dimethylformamide, dimethyl sulphoxide and N-methylpyrrolidone, and liquefied gases).

The surface-active agent can be an emulsifying, dispersing or wetting agent of ionic or nonionic type or a mixture of such surface-active agents. Examples which may be mentioned are salts of polyacrylic acids, salts of lignosulphonic acids, salts of phenolsulphonic or naphthalenesulponic acids, polycondesates of ethylene oxide with fatty alcohols, fatty acids or fatty amines, substituted phenols (in particular alkylphenols or arylphenols), salts of sulphosuccinic acid esters, taurine derivatives (in particular alkyltaurates), phosphoric acid esters of condensates of ethylene oxide with alcohols or phenols. fatty acid esters of polyols, and derivatives of the above compounds containing sulphate, sulphonate and phosphate groups.The presence of at least one surface-active agent is generally essential if the active ingredient and/or the inert carrier are not soluble in water and if the vehicle of application is water.

For their application, the compounds of the formula (I) are therefore generally in the form of compositions; these compositions according to the invention are themselves in a fairly wide variety of solid or liquid forms.

As forms of solid compositions, there may be mentioned dusting powders (with a content of compound of the formula (I) which can range up to 100%) and granules, in particular those obtained by extrustion, by compaction, by the impregnation of a granular carrier or by the formation of granules from a powder (the content of compound of the formula (I) in these granules being between 0.5 and 80% for the latter cases). The solid compositions most frequently contain 20 to 80% of active ingredient.

As forms of liquid compositions or compositions which are to be made up into liquid compositions on application, there may be mentioned solutions, in particular emulsifiable concentrates, emulsions, suspension concentrates, aerosols, wettable powders (or spraying powders), dry flowables and pastes.

The liquid compositions most frequently contain 10 to 80% of active ingredient.

The emulsifiable or soluble concentrates most frequently comprise 10 to 80% of active ingredient, and the emulsions or solutions which are ready for application contain 0.01 to 20% of active ingredient. In addition to the solvent, the emulsifiable concentrates can contain, where necessary, 2 to 20% of suitable additives, such as stabilisers, surface-active agents, penetrating agents, corrosion inhibitors, dyestuffs and adhesives.

Starting from these concentrates, emulsions or solutions of any desired concentration, which are particularly suitable for application to the plants, can be obtained by dilution with water.

Examples of emulsifiable concentrates are now given: Example 10 active ingredient 250 g ethylene oxide/alkylphenol condensate 30 g calcium alkylarylsulphonate 50 g petroleum distillation cut distilling at between 160 and 185'C 670 g Another formulation is: Example 19 active ingredient 350 g ethylene oxide/caster oil condensate 60 g sodium alkylarylsulphonate 40 g cyclohexanone 1 50 g xylene 400 g Another formulation is: Example 12 active ingredient 400 g ethylene oxide/alkylphenol condensate 100 g ethylene glycol methyl ether 250 g aromatic petroleum cut distilling at between 160 and 185"C 250 g Another formulation is:: Example 13 active ingredient 400 g phosphate of ethylene oxide/tristyrylphenol condensate 50 g phosphate of ethylene oxide/alkylphenol condensate 65 g sodium alkylbenzenesulphonate 35 g cyclohexanone 300 g aromatic petroleum cut distilling at between 160 and 185"C 150 g Another formulation is: Example 14 active ingredient 400 g/l alkali metal dudecylbenzenesulphonate 24 g/l 10:1 ethylene oxide/nonylphenol condensate 16 g/l cyclohexanone 200 g/l aromatic solvent q.s. 1 litre Another formulation of an emulsifiable concentrate uses the following:: Example 15 active ingredient 250 g epoxidised vegetable oil 25 g mixture of an alkylarylsulphonate and a polyglycol ether of fatty alcohols 100 g dimethylformamide 50 g xylene 575 9 The suspension concentrates, which can be applied by spraying, are prepared so as to give a stable fluid product which does not form a deposit (by fine grinding), and they usually contain from 10 to 75% of active ingredient, from 0.5 to 15% of surface-active agents, from 0.1 to 10% of thixotropic agents, from 0 to 10% of suitable additives, such as antifoam agents, corrosion inhibitors, stabilisers, penetrating agents and adhesives, and, as the carrier, water or an organic liquid in which the active ingredient is sparingly soluble or insoluble; certain organic solids, or inorganic salts, can be dissolved in the carrier in order to assist in preventing sedimentation or to act as antifreeze agents for the water.

A composition of a suspension concentrate is now given as an example: Example 16 active ingredient 50 g phosphate of ethylene oxide/tristyrylphenol condensate 50 9 ethylene oxide/alkylphenol condensate 50 g sodium polycarboxylate 20 g ethylene glucol 50 g organopolysiloxane oil (anti-foam agent) 1g polysaccharide 1 2.5 g water 316.5 g The wettable powders (or spraying powders) are usually prepared so as to contain 20 to 95% of active ingredient, and they usually contain, in addition to a solid carrier, from 0 to 5% of a wetting agent, from 3 to 10% of a dispersing agent and, where necessary, from 0 to 10% of one or more stabilisers and/or other additives, such as penetrating agents, adhesives, anticaking agents, and dyestuffs.

Various compositions of wettable powders are now given as examples: Example 1 7 active ingredient 50% calcium lignosulphonate (deflocculant) 5% isopropylnaphthalenesull,nonate (anionic wetting agent) 1% anti-caking silica 5% kaolin (filler) 39% Another example of a wettable powder, this time of 80% strength, is given below: Example 18 active ingredient 80% sodium alkylnaphthalenesulphonate 2% sodium lignosulphonate 2% anti-caking silica 3% kaolin 13% Another example of a wettable powder is given below: Example 19 active ingredient 50% sodium alkylnaphthalenesulphonate 2% low-viscosity methylcellulose 2% diatomaceous earth 46% Another example of a wettable powder is given below:: Example 20 active ingredient 90% sodium dioctyl-sulposuccinate 0.2% synthetic silica 9.8% Another composition of a spraying powder, this time of 40% strength, uses the following constituents: Example 21 active ingredient 400 9 sodium lignosulphonate 50 g sodium dibutylnaphthalenesulphonate 10 g silica 540 9 Another composition of a spraying powder, this time of 25% strength, uses the following constituents: Example 22 active ingredient 250 9 isooctylphenoxy-polyoxyethylene-ethanol 25 g mixture of equal parts by weight of Champagne chalk and hydroxyethylcellulose 1 7 g sodium aluminosilicate 543 9 kieselguhr 165 9 Another composition of a spraying powder, this time of 10% strength, uses the following constituents:: Example 23 active ingredient 100 g mixture of sodium salts of saturated fatty acid sulphates 30 g naphthalenesulphonic acid/formaldehyde condensate 50 g kaolin 820 9 To obtain these spraying powders or wettable powders, the active ingredients are intimately mixed with the additional substances, in suitable mixers, or a porous filler is impregnated with the molten active ingredient, and the mixture is ground in mills or other suitable grinders. This gives spraying powders of advantageous wettability and suspendability; they can be suspended in water at any desired concentration, and this suspension can be used very advantageously, in particular for application to the leaves of plants.

The dry flowables (more exactly, these are granules which are readily dispersible in water) have a composition substantially similar to that of the wettable powders. They can be prepared by the formation of granules from formulations described for the wettable powders, either by a wet process (bringing the finely divided active ingredient into contact with the inert filler and with a small amount of water, e.g. 1 to 20%, or of an aqueous solution of dispersing agent or binder, followed by drying and sieving) or by a dry process (compaction, followed by grinding and sieving).

A formulation of a dry flowable is now given as an example: Example 24 active ingredient 800 9 sodium alkylnaphthalenesulphonate 20 9 methylene-bis-(sodium napthalenesulphonate) 80 9 kaolin 100 9 In place of the wettable powders, it is possible to produce pastes. The conditions and modes of production and use of these pastes are similar to those of the wettable powders or spraying powders.

As already stated, the aqueous dispersions and emulsions, e.g. compositions obtained by diluting, with water, a wettable powder or an emulsifiable concentrate according to the invention, are included within the general scope of the compositions which can be used in the present invention. The emulsions can be of the water-in-oil or oil-in-water type and they can have a thick consistency such as that of a "mayonnaise".

All these aqueous dispersions or emulsions, or spraying mixtures, can be applied to the crops in which weeds are to be destroyed, by any suitable method, mainly by spraying, at doses which are generally of the order of 100 to 1 ,200 litres of spraying mixture per hectare.

The granules, which are intended to be placed on the soil, are usually prepared so that they have dimensions of between 0.1 and 2 mm, and they can be manufactured by agglomeration or impregnation. Preferably, the granules contain 1 to 25 % of active ingredient and 0 to 10% of additives, such as stabilizers, slow-release modifiers, binders and solvents.

One example of a granular composition uses the following constituents: Example 25 active ingredient 50 g propylene glycol 25 9 clay (particle size: 0.3 to 0.8 mm) 925 g As indicated above, the invention also relates to a method for controlling the growth of weeds at a locus used, or to be used, for growing crops, in particular cereals, such as wheat and also soya, which method comprises applying to the locus an effective amount of a compound according to the invention. The compounds of general formula I may be applied to the plants and/or to the soil.

In practice, the compounds are used in the form of herbicidal compositions according to the invention, which have been described above. In general, amounts of active ingredient ranging from 0.01 to 5 kg/ha, preferably from 0.1 to 2 kg/ha, give good results, it being understood that the choice of the amount of active ingredient to be used depends on the severity of the problem to be solved, the climatic conditions and the crop in question. The treatment can be carried out either as a pre-emergence treatment of the crops and adventitious plants, or as a presowing treatment of the crops with incorporation into the soil (such incorporation constitutes a further feature of the method of the invention), or as a post-emergence treatment. Other embodiments of the treatment method according to the invention can also be used: thus, it is possible to apply the active ingredient to the soil, with or without incorporation, before planting out a crop.

The treatment method of the invention can be used for annual crops and in the case of perenial crops; in the latter case, it is preferred to apply the active ingredients of the invention in a localised manner, e.g. between the rows of the said crops.

TABLE (I) American name Latin name Abbreviation Field corn CN Cotton CT Crops Wheat WT Rice RI Soybean SB Barnyard grass Echinochloa BYG crus-galli Giant foxtail Setaria faberii GTF Green foxtail Setaria viridis GF Crabgrass Digitaria CG sanguinaiis Velvet leaf Abutilon theophrasti VL Weeds Foxtail millet Setaria italica FM Cocklebur Xanthium pennsylvanicum CB Wild mustard Sinapis arvensis WM Pigweed Amaranthus retroflexus PW Morning glory Ipomea purpurea MG (annual) Prickly sida Sida spinosa PS Wild oat Avena fatua WO Wild buckwheat Polygonum convolvulus Ragweed Ambrosia artemisiifolia TABLE (II)

Weeds Crops Compound Pre- Dose in No. emergence kg/ha BYG GTF CG VL CB WM PW MG PS CT CN SB or postemergence 1 post 2.24 80 80 90 70 80 80 80 70 90 40 20 30 2 post 0.14 70 10 80 100 90 30 30 50 3 pre 1.12 60 30 0 100 100 0 20 post 1.12 90 100 100 100 100 90 70 50 3 (A) post 2.24 80 80 90 70 50 90 90 70 100 50 0 0 4 post 2.24 0 10 30 40 80 80 60 30 60 10 0 20 5 pre 1.12 100 100 90 100 80 100 100 90 100 50 40 30 post 1.12 60 50 10 70 90 100 100 60 60 10 10 10 6 pre 1.12 90 60 70 70 30 90 100 60 60 10 10 10 post 1.12 50 0 0 50 100 100 50 80 50 70 0 50 Table (III)

PRE-EMERGENCE POST-EMERGENCE Dose in kg/ha 2 1 0.5 0.25 1 0.5 0.25 0.125 Agropyron 90 50 20 0 Sorghum 100 100 100 100 Echinochloa 100 100 100 90 50 20 0 0 Panicum 10 100 100 100 80 80 0 0 Digitaria 100 100 100 100 100 90 10 0 Abutilon 100 100 100 60 100 80 50 20 Xanthium 100 0 0 0 100 100 100 Chenopodium 100 100 100 100 100 80 80 30 Amaranthus 100 100 100 100 100 100 100 90 Ambrosia 100 100 100 90 100 90 90 20 Polygonum 100 100 100 100 100 100 100 90 Ipomea 100 50 100 100 Sida 100 100 100 100 100 100 100 90 Galium 100 100 90 80 90 50 20 0 Alopecurus 90 80 20 10 0 0 0 0 Setaria viridis 100 100 100 100 100 90 10 0 Setaria faberii 100 100 100 100 90 60 20 0 Chrysanthemum 100 100 100 90 100 100 100 100 Sinapis 100 100 80 80 100 100 100 100 Stellaria 100 100 100 100 80 20 0 0 Wheat 0 0 0 0 10 0 0 0 Barley 10 10 0 0 10 0 0 0 Maize 10 0 0 0 0 0 0 0 Cotton 0 0 0 0 Soya 30 0 0 0 60 0 0 0 Table (IV)

PRE-EMERGENCE POST-EMERGENCE Dose in kg/ha 2 1 0.5 0.25 1 0.5 0.25 0.125 Galium 100 100 100 60 100 90 90 90 Setaria viridis 90 20 20 0 Echinochloa 60 10 10 0 Panicum 90 20 20 10 Digitaria 40 40 40 20 Abutilon 90 50 10 0 Xanthium 100 100 100 Chenopodium 100 100 100 100 100 100 100 80 Amaranthus 100 100 100 Ambrosia 100 100 100 90 Polygonum 100 100 100 100 100 100 100 100 Ipomea 100 100 100 100 Sida 100 90 Avena fatua 80 20 0 0 Alopecurus 90 30 50 0 Lolium 100 30 0 0 Setaria faberii 100 100 100 100 80 10 0 Chrysanthemum 100 100 100 100 100 100 100 100 Sinapis 100 100 100 100 100 100 100 100 Stellaria 100 10 0 0 Wheat 30 10 0 0 20 0 0 0 Barley 10 10 0 0 20 10 0 0 Maize 0 0 0 0

Claims (31)

1. A phenoxybenzoic acid derivative of the formula:

in which: X,, X2 and X3, which may be the same or different, each represent a halogen atom, a polyhalogenoalkyl radical; NO2; CN; an alkyl radical; an SO2-alkyl radical; SO2NH2; NO; or COOalkyl; Y, is -N = or -CH =; V2 is -N = or, when Y, is -CH =, a group -CX7 =; V3 as the oxygen or sulphur atom; X4 is the hydrogen atom or a substituted or unsubstituted alkyl radical; X5 is the hydrogen atom; an alkali metal atom; a cationic quaternary or non-quaternary ammonium group: a substituted or unsubstituted alkyl radical; or a halogen atom; Xe is a substituted or unsubstituted alkyl radical, or an aryl radical, which is substituted or unsubstituted; and X7 is the hydrogen atom or a halogen atom.

2. A compound according to claim 1 in which alkyl groups and radical within the definitions of the various symbols contain from 1 to 4 carbon atoms.

3. A compound according to claim 1 or 2 in which substituted alkyl radicals represented by X4 and X5 are substituted by halogen atoms, and in which, when Xe represents a substituted alkyl group or a substituted or unsubstituted phenyi radical, the substituents are one or more halogen atoms or alkyl, amino, cyano, nitro, alkoxy, hydroxy, formyl and mercapto groups, the alkyl and alkoxy substituents containing 1 to 4 carbon atoms.

4. A compound according to claim 1, 2 or 3 in which X, is CF3, X2 is Cl, X3 is Cl or NO2, Xe is H, Na, Cl or methyl and Y, and V2 are -CH =

5. A compound according to claim 4 in which X, is CF3, X2 is Cl, X3 is NO2, X5 is H, Na or Me, and Y, and V2 are -CH =

6. A compound according to any one of the preceding claims wherein V3 is oxygen.

7. A compound according to any one of the preceding claims wherein Xe is an unsubstituted alkyl group containing 1 to 4 carbon atoms or a phenyl group substituted by an alkyl group containing 1 to 4 carbon atoms.

8. A compound of general formula I prepared in any one of Example 1, 2, 3, 3(A), 4, 5 and 6.

9. A process for the preparation of a compound of formula I as defined in claim 1, which comprises reacting an acid chloride of the formula:

(in which the various symbols are as hereinbefore defined) with a sulphonamide of the formula: X,-SO,-NH-XS (Ill) in which Xe and Xe are as defined in claim 1.

1 0. A process according to claim 9, wherein the reaction temperature is from 50 to 1 50"C, and the reaction is carried out in a solvent and at a concentration of products of the formulae (II) and (I) of from 1 to 80% by weight.

11. A process according to claim 9 or 10 wherein the reaction temperature is from 80 to 1 10'C.

1 2. A process for the preparation of a compound of general formula I as defined in claim 1, in which Xe is a hydrogen atom, which comprises reacting an acid of the formula:

(wherein the various symbols are as defined in claim 1) with an isocyanate of the formula: X6-SO2-NCO wherein Xe is as defined in claim 1.

1 3. A process according to claim 12, wherein the reaction is carried out at from 20 to 100'C, in a solvent, the concentration of products of the formulae (IV) and (I) being from 5 to 70% by weight.

14. A process according to claim 1 3 wherein the reaction temperature is from 40 to 80"C.

1 5. A process according to any one of claims 9 to 14 followed by the step of converting by known methods a compound of formula I obtained wherein Xe is a hydrogen atom into a corresponding compound of formula I wherein X5 is an alkali metal atom.

1 6. A process according to any one of claims 9 to 1 4 followed by the step of reacting a compound of formula I obtained wherein Xe is a hydrogen atom with a hypohalite to obtain a corresponding compound of formula I wherein Xe is a halogen atom.

1 7. A process according to any one of claims 9 to 1 6 substantially as herein before described.

1 8. A process according to any one of claims 9 to 1 6 substantially as hereinbefore described in any one of Examples 1, 2, 3, 3(A), 4, 5 and 6.

1 9. A compound according to claim 1 when prepared by a process according to any one of claims 9 to 18.

20. A herbicidal composition which comprises, as active ingredient, a compound according to any one of claims 1 to 8 and 19, in association with an inert carrier which is acceptable in agriculture.

21. A composition according to claim 20, which contains 0.05 to 95% by weight of active ingredient.

22. A composition according to claim 20 or 21, which is liquid and which contains 10 to 80% of active ingredient.

23. A composition according to claim 20 or 21, which is solid and contains 20 to 80% of active ingredient.

24. A composition according to any one of claims 20 to 23, which contains 0.1 to 20% of surface-active agent.

25. A herbicidal composition according to claim 20 substantially as herein before described in any one of Examples 10 to 25.

26. A method for controlling the growth of weeds at a locus used, or to be used, for growing crops, which comprises applying to the locus an effective amount of a compound according to any one of claims 1 to 8 and 1 9.

27. A method according to claim 26, wherein the crop is a soya crop infested or susceptible to infestation by at least one of the following weeds: abutilon, xanthium, ipomea and polygonum.

28. A method according to claim 26, wherein the crop is a cereal crop infested or susceptible to infestation by at least one of the folowing weeds: chenopodium, amaranth, ambrosia, polygonum, chrysanthemum, mustard, stellaria and yellow bedstraw.

29. A method according to any one of claims 26 to 28, wherein the compound of the formula (I) is applied at a rate of 0.01 to 5 kg/ha.

30. A method according to any one of claims 26 to 28, wherein the compound of the formula (I) is applied at a rate of 0.1 to 2 kg/ha.

31. A method according to claim 26, substantially as hereinbefore described.