NL8006569A - 2,5-DIALKYLPHENYLURUM DERIVATIVES, PROCESS FOR THE PREPARATION THEREOF, CONTAINING HERBICIDE PREPARATIONS CONTAINING THE SAID DERIVATIVES AND METHODS FOR THE PREVENTION OF WEEDS USING THESE DERIVATIVES. - Google Patents

Description

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2,5-DIALKYLPHENYLURUM DERIVATM, METHOD FOR PREPARING IT, HERBICIDE PREPARATIONS CONTAINING THE MENTIONED DERIVATIVES AND METHODS FOR THE PREVENTION OF WEEDS USING THESE DERIVATIVES

The present invention relates to certain 2,5-dialkylphenylurea derivatives, to a method of preparation thereof, to herbicidal compositions containing said derivatives, and to a method of weed control using these derivatives.

In U.S. Pat. A very large group of urea derivatives with herbicidal properties are described. In the period of more than 25 years that has elapsed since these compounds were prepared, much research has been conducted on the use of urea derivatives as herbicides, which has led to commercial use in some of them. Although some of these commercially available urea herbicides have been found to be suitable for use on certain crops - for example, 3 - (1 - sopropylphenyl) -1,1-dimethylurea or "Isoproturon" on cereals and 3 - ( 3-Trifluoromethylphenyl) -1,1-dimethylurea or "Cotoron" on cotton plants - there is still a need for new compounds that combine a favorable spectrum of activity against weeds with a high tolerance to the crop.

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It has now been found that some 3- (2,5-di-alkyl phenyl) -1,1-dimethylurea, which are not specifically described in the above-mentioned U.S. Pat. 2,655-1 + 1 + 7-have particularly attractive herbicidal properties.

The invention therefore relates to a compound of the general formula I: \ / Q \ - NH-CO-li (CH3) 2 (I) \ R1 in which an alkyl group has 1 or 2 carbon atoms and is an alkyl group with branched or straight chain and 2-1 + carbon atoms, a cycloalkyl group with 3-1 + carbon atoms or a methyl-10 cyclopropyl group. These new 2,5-dialkylphenylureas have a high herbicidal activity for various weeds, while being extremely tolerant of the cotton plant.

R j is the above formula I is preferably methyl and R 15 is preferably a branched chain alkyl group having 3 or 1+ carbon atoms, for example isopropyl or tertiary butyl or a cyclopropyl group. In this connection, the most preferred compound is 3- (2-methyl-5-isopropylphenyl) -1,1-dimethylurea.

The invention also relates to a process for the preparation of a compound of the formula I, wherein an aniline of the general formula II or a hydrohalide salt thereof: / O y- «h2 (II) E1 8 00 6 56 9 ► * 3 wherein and R 4 have the above meanings, are reacted with: (a) a dimethyl carbamoyl halide, preferably the chloride, or (b) phosgene (COCl 4), to prepare an isocyanate of the general formula: (in)

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R1 and at least part of the isoeyanate are reacted with dimethylamine.

Process (a) can be performed with or without solvent. Suitable solvents are hydrocarbons and halogenated hydrocarbons, for example benzene, toluene or carbon tetrachloride. The process is preferably carried out under substantially anhydrous conditions. Since the reaction is a condensation reaction removing hydrogen halide, it is preferably carried out in the presence of a dehydrohalogenating agent; organic or inorganic bases can be suitably used; sodium acetate has proved particularly useful when operating without a solvent, and organic bases such as triethylamine or pyridine are suitable when a solvent is used.

The reaction is preferably carried out at a temperature of 0-80 ° C, preferably at room temperature, and the reaction mixture can be worked up by conventional means.

Process (b) is suitably carried out in the presence of a solvent, for example, a hydrocarbon, such as.

toluene, at a temperature of 80-120 ° C; it is advantageous to allow the reaction to proceed at the reflux temperature of the solvent used. The obtained isoeyanate of formula III

8 006 5 6 9 k may be separated from the reaction mixture, if desired, but "preferably in situ with reaction of dimethylamine. This reaction is suitably carried out at a temperature of 0-30 ° C, preferably at room temperature. The desired product 5 · can be separated by any suitable method.

The invention further relates to a herbicidal composition containing the compound of formula I as well as a suitable carrier. The invention also relates to a method for preventing unwanted plant growth in a field, wherein the compound or a preparation according to the invention is applied to the field.

A carrier for a preparation according to the invention can be any material with which the active component has been mixed for the purpose of applying it to the crop, seed, soil or other object to be treated, or to store, transport or process it to ease. A carrier may be a solid or liquid material, as well as a material which is gaseous under normal conditions but is compressed into a liquid, and any carrier material commonly used in formulating herbicidal compositions.

Suitable solid carriers are natural and synthetic clays and silicates, for example natural silicas, such as diatomaceous earth, magnesium silicates, for example talc, magnesium aluminum silicates, for example attapulgites and vermiculites; aluminum silicates, for example kaolinites, montmorillinites and micas; calcium carbonate; calcium sulfate; synthetic hydrated silicon oxides and synthetic calcium or aluminum silicates; elements such as carbon and sulfur; natural and synthetic resins such as coumarone resins, poly-30 vinyl chloride and styrene polymers and copolymers; solid polychlorophenols; bitumen; waxes such as beeswax, paraffin and chlorinated mineral paraffins, as well as solid fertilizers, for example, superphosphates.

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Examples of suitable liquid carriers are water, alcohols such as isopropanol and glycols; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethers; aromatic or araliphatic hydrocarbons, such as benzene, toluene and xylene; petroleum fractions, such as kerosene, light mineral oils; chlorinated hydrocarbons, such as carbon tetrachloride, perchloarethylene, trichloroethane. Mixtures of different liquids are often suitable.

Agricultural preparations are often prepared and transported in concentrated form, after which they are diluted by the consumer before use. This dilution is facilitated by the presence of small amounts of a carrier, which is a surfactant. In a composition according to the invention, therefore, at least one carrier is a surfactant. For example, the composition may contain at least two carriers, at least one of which is a surfactant.

The surfactant can be an emulsifying agent, a dispersing agent or a wetting agent; the substance can be non-ionic or ionic. Examples of useful surfactants are the sodium or calcium salts of polyacrylic acids and lignin sulfonic acids; the condensation products of fatty acids or aliphatic onines or amides with at least 12 carbon atoms per molecule with ethylene oxide and / or propylene oxide; the fatty acid esters of glycerol, sorbitan, sucrose or pentaerythritol; Condensates thereof with ethylene oxide and / or propylene oxide; condensation products of fatty alcohols or alkylphenols, for example ρ, -etylphenol or p-octylcresol, with ethylene oxide and / or propylene oxide; sulfates or sulfonates of these condensation products; alkali or alkaline earth metal salts, preferably sodium salts of sulfuric or sulfonic acid esters containing at least 10 carbon atoms per molecule, for example sodium lauryl sulfate, secondary sodium alkyl sulfates, sodium salts of sulfonated castor oil and sodium alkylaryl sulfonate; and polymers of ethylene oxide and copolymers of ethylene oxide and propylene oxide.

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The preparations obtained according to the method according to the invention can be formulated in the form of spray powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosols. Spray powders 5 usually contain 25, 50 or 75 wt% active material and, in addition to solid inert carrier, usually 3-10 wt% of a dispersant and, if necessary, 0-10 wt% of one or more stabilizers and / or or other additives, such as penetrants or adhesives. Dusting powders are usually formulated in the form of a dusting powder concentrate with a composition similar to that of a wettable powder, but without dispersant, and are diluted on site with a further amount of solid carrier to a formulation usually 0.5-10 wt% active material. contains. Granules are usually prepared in a size of 1,676-0,152 mm using agglomeration and impregnation techniques. Granules generally contain 0.5-25 wt% active material and 0-10 wt% additives such as stabilizers, slow release agents of the active material, and binders. Emulsifiable concentrates contain, in addition to the solvent and, if required, auxiliary solvent, 10-50% w / v active material, 2-20% w / v. Emulsifiers and 0-20% w / v. Other additives, such as stabilizers, penetrating agents and anti-corrosion substances. Suspension concentrates are usually formulated to provide a stable, non-sediment-forming, free-flowing product and usually contain 10-75 wt.% Active material, 0.5-15 wt.% Dispersants, 0.1-10 wt. based on suspending agents, such as protective colloids and thixotropic agents, 0-10% by weight of other additives, such as anti-foaming agents, anti-corrosion agents, stabilizers, penetrating agents and adhesives and water or an organic liquid in which the active material is practically insoluble ; certain organic solids or inorganic salts can be dissolved in the formulation to help prevent sedimentation or as antifreeze agents for water.

8006569 7

Aqueous dispersions and emulsions, for example, compositions obtained by diluting a spray powder or a concentrate according to the invention with water also fall within the scope of the present invention. The said emulsions can be from the water-in-oil or the oil-in water type and may have a thick mayonnaise-like consistency.

The preparations obtained according to the method according to the invention can also contain other ingredients, for example other compounds with insecticidal or fungicidal properties. The invention is further illustrated in the following Examples.

EXAMPLE 1 - Preparation of 3- (2-methyl-5-isopropylphenyl) -1,1-dimethyl-urea-2-methyl-5-isopropylaniline (4.5 g) and anhydrous sodium acetate (2.4 g) were added as a solid mixture stirred together and dimethylcarbamoyl chloride (5.4 g) was added over 15 minutes. The mixture was allowed to stand at room temperature overnight, after which it was treated with water and extracted with methylene chloride. After the mixture was dried over magnesium sulfate, 1st solvent was evaporated and the resulting solid was recrystallized from hexane. 1.5 g of the desired product with a melting point of 72-73 ° C were obtained.

Analysis: C Η N

Calculated for 70.9 9.1 ^ 12.7 25 '- Found 71 »0 9» 3 12.5 EXAMPLE 2 - Alternative preparation method for the compound __ of Example 1 * COCl gas was passed for half an hour through a refluxing solution of 2-methyl-5-isopropylaniline (8 g) in toluene (150 ml). Dry nitrogen gas was passed through the solution to remove excess COCl 2 and then dimethylamine (8g, anhydrous) dissolved in toluene (50ml) was added at room temperature. The solution was then evaporated and the residue was treated with hexane to obtain 9.5 g of the desired compound as a white precipitate with a melting point of 72 ° C.

O Λ Λ cc cc n 8 EXAMPLE 3 - Preparation of 3- (2-methyl-5-tert-butylphenyl) -1,1-dimethyl-urea-2-methyl-tert-butylaniline (T g) dissolved in toluene ( 10 ml) • was added dropwise to a solution of COCl 2 in toluene (100 ml). The resulting reaction mixture was heated to reflux temperature for half an hour and dry nitrogen gas was passed through the solution to remove excess COClg. After cooling, anhydrous dimethylamine (3g) dissolved in toluene (10ml) was added to form a precipitate. The precipitate was filtered and recrystallized from hexane to yield 6.5 g of the desired product, mp 116-117 ° C.

Analysis: CH

Calculated for C 14 HggNgO 71 * 2 9.3

Found 71.2 9.6. EXAMPLE k - Rebid action

In order to determine its herbicidal activity, compounds of the invention (Examples 1 and 3) and a compound deviating from the invention, 3- (2,5-dimethylphenyl) -1,1-dimethylurea, were tested using the next::.

20 plants: corn ,. Zea mays (Mz); rice, Oryza sativa (R); water grass, Echinochloa crusgalli (BG), oats, Avena sativa (0); linseed,

Linum usitatissimum (L); mustard, Sinapis alba (M); sugar beet,

Beta vulgaris (SB).

Two types of tests were carried out, namely tests.

25 before and after the crop has emerged. In the tests of the first kind, the soil in which seeds of the said plant species had recently been sown was sprayed with a liquid preparation of a compound according to the invention. The latter tests were divided into two types, namely tests 30 in which the earth was soaked and tests in which the leaves were sprayed. In the soil soaking experiments, the soil in which seedlings of the above plant species grew up was soaked with a liquid preparation containing a compound of the invention, and in the second 8 00 6 56 9 9 species, the seedlings were seeded with such a preparation. sprayed.

The soil used in the experiments was a prepared horticultural loam.

The preparations used in the experiments were prepared by diluting with a solution of the compounds in acetone containing 0.4 wt.% Of an alkylphenol / ethylene oxide condensate commercially available under the name Triton X-155. In the soil spraying and spraying the leaves of seedlings, the acetone solutions were diluted with water and the resulting preparations were used at dosages corresponding to 5 and 1 kg of active material per hectare, respectively, in a volume equal to 650 liters per hectare. In the soil soaking experiments, a volume of the acetone solution was diluted with water and the resulting composition was used at a dose equal to 10 kg of active material per hectare in a volume equal to about 3,000 liters per hectare.

In the pre-crop tests, untreated seeded soil was used for comparison, and in the post-crop tests, untreated soil in which seedlings grew was used as a reference material.

The herbicidal activity of the compounds was visually determined and recorded on a 0-9 ascending scale eleven days after spraying the leaves and watering the soil and twelve days after spraying the earth. The rating 0 means no effect on the treated plants, the rating 9 indicates the death of the plant. An increase of 1 unit on the linear scale corresponds to an improvement of about 10% in operation.

The results are shown in Table I.

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8 00 6 5 6 9 11 EXAMPLE 5 - Selective herbicidal action

The herbicidal activity before crop emergence of 3- (2-methyl-1-i-sopropylphenyl) -1,1-dimethylurea was determined in the following manner using different crops and weeds. Seeds of the different test plants were sown in containers, and the test compound was applied to the ground in two different fixed doses of 1.1 and 2.2 kg / ha. The temperature, humidity and exposure of the planted soil were controlled for 9-10 days. Germination and growth 10 were graded on a scale of 0-9, where the ratings had the following meanings:

Valuation Meaning 9 No living tissue 8 Living tissue, but death of plant can be expected 15 T Plant very affected, but it is expected that the plant will survive 6 Plant seriously affected, but full recovery can be expected 5 Unacceptable damage to the crop, infestation of weeds insufficient 3-h Obvious infestation 1-2 Plant slightly affected, perhaps by the test compound or by biological cause 20 0_ No perceptible result.

The following plants were tested: maize, Zea mays (dekalb X363); cotton, Gossypium hirsutum; rice, Oryza sativa (Calrose); negro millet, Sorghum vulgare (Pioneer 265); soybean, Glycine max (Amsoy 71); wheat, Triticum aestivum (Cajeme 71); Water grass, Echinochloa crusgalli; blood-red finger grass, Digitaria sanguinalis; cottony dravik, Brornus tectorum; big foxtail, Setoria faberi; Sudan grass, Sorghum hale-pense; wild oats,

Avena fatua; yellow foxtail, setaria lutescens; burdock, Xanthium pensylvanicum; hemp sesbania, Sesbania exaltata; thorn apple, 30 Datura stramonium; white goosefoot, Chenopodium album; kaladana plant, Ipomoea purpurea; mustard, Sinopis alba; louse reported, Amoranthus retroflexus; spinesida, Sida spinosa; blunt-leaved cassia, Cassia obtusifolia; witbol, Abutilon theophrasti.

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The results of the test are shown in Table II below:

TABLE II

Phytotoxicity at indicated _dose_

Plant species 1.1 kg / ha 2.2 kg / ha

Maize 3 9 -

Cotton 0 0

Row st 6 8

Negro millet 5 9

Soybean 8 9

Sugar beet 9 9

Wheat b 6

Water grass 9 9

Blood red finger grass 9 9

Fluffy swad 3 8

Large foxtail 6 9

Sudan grass 9 9

Wild oats ^ T

Yellow foxtail 9 9

Burdock 7 8

Hemp sesbania 6 9

Thorn apple 9 9

White goosefoot 9 '9 »

Kalanana plant 9 9

Mustard 9'9

Reported 9 9

Spinesida 9 6

Cassette leaves 6 9

Witbol 9 9 8 00 6 5 6 9 4 13

As shown in Table II above, the compound of the invention has 3- (2-methyl-5-isopropylphenyl) -1,1-dimethyl-urea. essentially no toxic effect on cotton, while this compound gives good results in controlling different weeds.

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8006569

Claims (11)

1¼ * 1. Compound of the general formula:. S-Λ / Qy-hh-co-n (ch3) 2 E1 where R ^ is an alkyl group of 1 or 2 carbon atoms and Rg is a branched or straight chain alkyl group with 2-h carbon atoms or a cycloalkyl group having 3-¼ carbon atoms or a methylcyclopropyl-5 group. 2. A compound according to claim 1, characterized in that R 1 is methyl. 3. A compound according to claim 1 or 2, characterized in that Rg is a branched chain alkyl group with 3 or H carbon atoms or a cyclopropyl group. 3- (2-methyl-5-isopropyl-phenyl) -1,1-dimethyl-urea. 5. A process for the preparation of a compound according to claim 1 or 2, characterized in that an aniline of the general formula II or a hydrohalide salt thereof, wherein R 1 and R 5 have the meaning as defined in claim 1 or 2, in reaction is effected with: (a) a dimethyl carbamoyl halide; or (b) phosgene, to prepare isocyanate of the general formula: 8 0 0 6 5 6 9 2 / ny-00 / and at least a portion of the isocyanate is reacted with dimethylamine. 6. Process according to claim 5, characterized in that process (a) is carried out in the presence of a dehydrohalogenating agent. Process according to claim 5s, characterized in that process (a) is carried out using dimethylcarbamoyl chloride. 8. Herbicidal composition, characterized in that the composition contains a compound according to any one of claims 1-¾ and a suitable carrier. Preparation according to claim 8, characterized in that it contains at least two carriers of which at least one is a surfactant. Method for preventing unwanted plant growth in a field, characterized in that a compound according to any one of claims 1--or a preparation according to claim 8, or 9 is applied to the field. 11. Method for controlling unwanted weeds in cotton, characterized in that a compound according to any one of claims 1-¾ or a preparation according to claim 8 or 9 'is applied to the relevant field. 8006569