FR2471371A1 - UREA DERIVATIVE, PROCESS FOR OBTAINING HERBICIDAL COMPOSITIONS CONTAINING THE SAME, AND METHOD FOR CONTROLLING WEEDS USING THE SAME - Google Patents

Abstract

THE INVENTION CONCERNS A NEW DERIVATIVE OF UREA. THIS DERIVATIVE MEETS THE FORMULA: (CF DRAWING IN BOPI) APPLICATION: THIS UREA DERIVATIVE SHOWS EXCELLENT HERBICIDE PROPERTIES.

Description

2471,371,

  The present invention relates to a urea derivative, a process for obtaining it, herbicidal compositions containing it and a method for controlling weeds

by means of this one.

  U.S. Patent 2,655,447 discloses an extremely broad class of urea derivatives having herbicidal properties. During the 25 years since these compounds were obtained, much research has been done into the use of ureas as herbicides. The most important urea derivative is probably 3- (4-isopropylphenyl) -1,1-dimethylethylurea which is sold under the trade name "Isoproturon". This compound is used extensively in Europe for weed control in winter cereals. Its main advantages are that it is extremely active against a wide variety of herbs and

  that it can be used both pre-emergence and post-

  emergence, both in autumn and spring. Its main disadvantage is that it does not control some commercially important weeds, including perennial broadleaf weeds, grass weeds,

scratches and veronics.

  It has now been found that a certain phenyl derivative

  urea which is not specifically described in the US Pat. 2655. 447 and whose phenyl ring bears two substituents

  specific, has particularly useful herbicidal properties.

  The subject of the invention is therefore the compound of formula CH 3% i-C 3 H 7 NH-CO N (CH 3) 2 (O)

  i.e. 3- (3-methyl-4-isopropylphenyl) -1,1-dimethylurea.

  This compound is particularly useful for controlling, in pre-

  emergence or postemergence, weeds that grow

  in cereal crops such as maize, barley or special-

  wheat. As illustrated by the results presented in Examples 4 and 5 below, this compound has clear advantages over Isoproturon, a commercial herbicide, for the control of

  weeds in wheat crops.

  The subject of the invention is also a method for obtaining

  the compound of formula (0) which comprises reacting the aniline of formula:

CH3 (I)

  or a halohydrate thereof: (a) either with a dimethylcarbamoyl halide, preferably chloride, (b) or with phosgene (COC12) to obtain the isocyanate of formula CH

\ (II)

î-C3 7 NCO

  and reacting at least a portion of the isocyanate with

dimethylamine.

  Process (a) can be carried out with or without a solvent.

  Suitable solvents include hydrocarbons and halogenated hydrocarbons, for example benzene, toluene or carbon tetrachloride. Preferably, it is carried out under substantially anhydrous conditions. Since the reaction is a condensation reaction involving removal of hydrogen halide, it is preferably carried out in the presence of an agent to remove said halide; organic or mineral bases are suitable for this purpose; It has been found that sodium acetate is particularly useful when operating without solvent and that organic bases, such as triethylamine or pyridine, are suitable when using a solvent. The reaction is preferably carried out at a temperature of from 0 ° to 800 ° C., advantageously at room temperature, and the mixture can then be treated by conventional means. Process (b) is advantageously carried out in the presence of a solvent, for example a hydrocarbon, such as toluene at a temperature of 80 to 120 ° C .; advantageously

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  the reaction can be carried out at the reflux temperature of the solvent used. If desired, the resulting isocyanate of formula (II) may be isolated from the reaction mixture, but

  preferably it is reacted in situ with dimethylamine.

  This reaction is advantageously carried out at a temperature of 0 to 300C, conveniently at room temperature. We

  can isolate the desired product by any suitable method.

  prayed. The invention further relates to a herbicidal composition comprising the compound of formula (0) and a carrier (or vehicle) suitable. The invention also relates to a method for controlling the growth of undesirable plants in one place, which consists in applying the compound to this location.

  according to the invention or a composition according to the invention.

  In some cases, it may be desirable to mix the compound of the invention with one or more other compounds having herbicidal activity, for example to change the spectrum of activity. Thus, the compound according to the invention can be mixed with other broad-spectrum herbicides, such as

  that 2- (4-chloro-6-ethylamino-s-triazin-2-ylamino) -2-methyl-

  propionitrile (product known under the trade name "Cyanazine") or with more specialized narrow spectrum herbicides, such as alanine wild boar herbicides, described in GB 1,164,160, which include, in particular, N-benzyl- Ethyl N- (3,4-dichlorophenyl) -2-aminopropionate (known under the trademark "Benzoylprop

  and the racemic mixture or (-) isomer of N-benzoyl-N-

  Isopropyl or methyl (3-chloro-4-fluorophenyl) -2-aminopropianate (herbicides known under the names "Flamprop

isopropyl "and" Flamprop methyl ").

  A carrier, in a composition according to the invention, is any substance to which the active ingredient is mixed to facilitate application to the place to be treated, which may be for example a plant, a seed or a soil, or to facilitate storage, transportation or handling. The carrier may be a solid or a liquid, including a substance that is normally gaseous but has been compressed to form a liquid; any of the carriers normally used for the preparation of herbicidal compositions can be used. Suitable solid supports include, in particular, natural and synthetic clays and silicates, for example natural silicas, such as diatomaceous earths, magnesium silicates, for example talcs, magnesium aluminum silicates, for example attapulgites and

  vermiculites, aluminum silicates, for example kaoli-

  nites, montmorillonites and micas, calcium carbonate

  calcium, calcium sulphate, hydrated silicon oxides

  synthetic and calcium or synthetic aluminum silicates

  ticks; elements, for example carbon and sulfur, natural and synthetic resins, for example coumarone resins, polyvinyl chloride and polymers and copolymers of styrene, solid polychlorophenols, bitumen, waxes, for example, beeswax, paraffin wax and chlorinated mineral waxes, and solid fertilizers,

for example, superphosphates.

  Suitable liquid carriers include water, alcohols, for example isopropanol and glycols, ketones,

  for example acetone, methyl ethyl ketone, methyl isobutane

  tyl-ketone and cyclohexanone, ethers, aromatic or arylaliphatic hydrocarbons, for example benzene, toluene and xylene, petroleum fractions, e.g.

  kerosene and light mineral oils, hydrocarbons

  chlorinated bures, for example carbon tetrachloride,

  chlorethylene and trichloroethane. Mixtures of different

liquids are often appropriate.

  The agricultural compositions are often prepared and transported in a concentrated form which the user then dilutes before application. The presence in small quantities of a support

  which is a surfactant facilitates the dilution process.

  Thus, preferably, at least one support, in a composition according to the invention, is a surfactant. For example, the composition may contain at least two supports, at least two of which

one is a surfactant.

  The surfactant may be an emulsifying agent, a dispersing agent or a wetting agent; it may be no

  ionic or ionic. Examples of suitable surfactants

  are the sodium or calcium salts of the polyacrylic acids

  and lignin sulphonic acids, the condensation products of fatty acids or aliphatic amines, containing at least 12 carbon atoms per molecule, with ethylene oxide and / or propylene oxide, the esters of fatty acids

  glycerol, sorbitan, sucrose or pentaerythritol

  tol, the condensation products of these with the oxide

  of ethylene and / or propylene oxide, condensation products

  fatty alcohol or alkylphenols, for example p-octyl-

  phenol or p-octylcresol, with ethylene oxide and / or propylene oxide, the sulphates or sulphonates of these condensation products, the alkaline or alkaline earth salts, preferably the sodium salts, of sulfuric or sulphonic acid esters containing at least 10 carbon atoms per molecule,

  for example sodium lauryl sulphate, alkyl sulphates se-

  condenses of sodium, the sodium salts of castor oil

  and sodium alkylarylsulphonates, such as sodium dodecylbenzenesulfonate, as well as ethylene oxide polymers and ethylene oxide copolymers and

of propylene oxide.

  The compositions of the invention may for example be prepared in the form of wettable powders, spray powders, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosols. Usually, the wettable powders contain 50% and 75% of active ingredient and besides the solid inert carrier they usually contain 3% to 10% by weight of a dispersing agent and, if necessary, 0% to 10% by weight of the active ingredient. one or more stabilizers and / or other additives, such as

  penetrating agents or adhesive tackifiers.

  The powders to be sprayed are usually prepared under

  form of a powdery concentrate having a similar composition

  to a wettable powder but without dispersion agent and diluted in the field with

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  solid support to obtain a composition usually containing 0.5 to 10% by weight of active ingredient. The granules are usually prepared in such a way that they have

  particle size of 1.676 to 0.152 mm and can be manufactured

  quer by agglomeration or impregnation processes. Generally, the granules contain 0.5 to 25% by weight of active ingredient and 0 to 10% by weight of additives, such as stabilizers, modifiers for slow release and binders. Emulsifiable concentrates usually contain, in addition to a solvent and if necessary, a cosolvent, 10 to 50% w / v of active ingredient, 2 to% w / v emulsifiers and 0 to 20% weight / volume of other additives, such as stabilizers, penetrants and corrosion inhibitors. In-suspension concentrates are usually dosed to provide a fluid, stable, non-sedimenting product and usually contain 10 to 75% by weight of active ingredient, 0.5 to% by weight of dispersing agents, 0, 1 to 10% by weight of suspending agents, such as protective colloids and thixotropic agents, 0 to 10% by weight of other additives, such as defoamers, corrosion inhibitors, stabilizers, penetrating agents and tackifiers as well as water or an organic liquid in which the active ingredient is substantially insoluble; certain organic solids or mineral salts may be in the dissolved state in the composition to better prevent sedimentation or as

antifreezes for water.

  The invention also encompasses dispersions and emulsions

  aqueous ions, for example the compositions that are obtained

  by diluting a wettable powder or a concentrate according to the invention

  with water. The emulsions can be of the water-type

  in - oil or oil-in-water and may have a

  thick tan similar to mayonnaise.

  The compositions of the invention may also contain other ingredients, for example other compounds having

  insecticidal or fungicidal properties.

  The following examples illustrate the invention.

EXAMPLE 1

  Preparation of 3- (3-methyl-4-isopropylphenyl) -1,11-dimethylu-

  7.4 g of 3-methyl-4-isopropylaniline and 0.5 g of anhydrous sodium acetate were stirred together as a solid mixture and 5.4 g of chloride were added over a period of 15 minutes. of dimethylcarbamoyl. The mixture was left overnight at room temperature and then treated with water and then extracted with methylene chloride. After drying on

  magnesium sulfate, the solvent was evaporated and recreated

  the solid obtained is crystallized from a mixture of hexane and toluene.

  3.5 g of the desired product having a melting point were obtained

between 153 and 154 C.

  Analysis C H N calcd for C13H20N2O 70.9 9.1 12.7 found 69.9 9.1 12.1

EXAMPLE 2

  Other method of preparation of the compound of the invention

  5 g of 3-methyl-4-isopropylanilide were refluxed.

  line (80% purity) in 150 ml of toluene while passing COC12 gas through the solution for about 1 1/2 hours and then dry nitrogen was passed through the solution for

  eliminate excess COCl2. After cooling to the end

  At room temperature, 5 g of dimethylamine in 20 ml of toluene was added to the reaction mixture. The toluene was evaporated, hexane was added to the residue and filtered off.

  the precipitate, ie 5.5 g of the desired product. After recrystalli-

  in a mixture of hexane and toluene, the desired product

  had a melting point of 154 C.

EXAMPLE 3

  This example illustrates the preparation of the

  which is 3-methyl-4-isopropylaniline.

  186 g of 3-methylaniline were dissolved in 600 ml of 85% by weight sulfuric acid. The mixture was heated to 80 ° C. and then 120 g of isopropyl alcohol was added. The mixture was stirred at 800C for 6 hours. At the end of this time,

  the mixture on ice and the addition of hydroxide

  the mixture was poured on ice and hydroxyl

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  of ammonium until the mixture is neutral. We have

  diethyl ether was added and the ethereal extract was evaporated.

  re. The residue was distilled to give 110 g of the desired product, boiling point 1000C at a pressure of 3.3 x 102 pascals

EXAMPLE 4

  Selective herbicidal activity of the compound of the invention Comparative test a) In this test, the selective herbicidal activity in wheat of 3- (3-methyl-4-isopropylphenyl) -1,1-dimethylurea was compared with that of the Isoproturon, commercial herbicide

  for wheat, which is 3- (4-isopropylphenyl) -1,1-dimethylurea.

  Pre-emergence trials were conducted on wheat, Triticum vulgare, sappo variety, and post-emergence trials on the Maris Huntsman variety. The weed species tested were: quackgrass, Aqropyron repens (Co), wild oats, Avena fatua / ludoviciana (Wo), perennial ryegrass, Lolium multiflorum (Rg), annual bluegrass, Poa annua (Pa), the bentgrass, Agrostis tenuis (Bt), the foxtail, Alopecurus myosuroides (Am), the ear of the wind, Apera Spicaventis (Wg), the chickweed, Stellaria media (St), the Persian veronica, Veronica persica (Sw), Cleavers, Galium aparine (Gg), Persicaria with leaves of patience, Polygonum lapathifolium (Pp), Purple cutthroat, Lamium purpureum (Dn), Wild mustard, Sinapis arvensis (Ck), the matricaria, Matricaria spp (Mw), the Shepherd's Purse-Capsella, Capsella bursa-pastoris (Sp), the Poppy, Papaver

rhoeas (Po).

  The active ingredients were made into emulsifiable concentrates containing 20% by weight of active ingredient, 10% by weight of mineral oil, emulsifiers and xylene as the solvent. Each concentrate was diluted with water and sprayed on the test plants at 6.0 kg / ha, 2.0 kg / ha, 0.6 kg / ha, 0.2 kg / ha, 0.06 kg / ha and 0.02 kg / ha of active ingredient. We did quad tests

  for each dose, both pre-emergence and post-emergence

  gence. In pre-emergence trials, untreated seeded soil is used as a control and in the tests

  in post-emergence, untreated soil bearing young plants.

  After 21 days in the post-emergence test and 28 days in the pre-emergence test, the effects of the active ingredients were visually assessed on a scale of 0 to 9, with a score of 0 indicating similar growth. to that of the untreated witness and note 9 indicating death. With this scale, an increment of one unit on the linear scale corresponds

  at an effect increase of about 10%.

  The results were subjected to a probability analysis in which a computer estimated the parameters, a and b in a relation of the form:

  Probability (% response) = a + b log (dose) -

  By means of the curve obtained, it is possible to calculate the doses corresponding to a given level of response. In this example, for each species, the GID50 has been calculated, that is to say

  the dose required to give a 50% response to the

active.

  From the values obtained, a selectivity factor for each weed was calculated in comparison with wheat, by the following relation: selectivity factor GID50 wheat GID50 weed

  The greater the selectivity factor, the greater the herbivity

cide is selective.

  Finally, the ratio of the selectivity factor of the compound according to the invention to the selectivity factor of Isoproturon was calculated. A value greater than 1 indicates that the compound according to the invention is more selective than Isoproturon. The

  The results are shown in Table 1 where the compound according to the invention

  is called A and Isoproturon I.

TABLE 1

Pre-emergence test

Selectivity factor

quick

I A

  Report of selectivity factors

1,231,67

  0.6 2.1 17.6, 5 61.5 12.3 11.2 2.6 0.7 3.3 8.2 7.2 1.6 2.8 9.3, 9 83.5 9 , 3 11.9 9.3 1.8 7.0 16.7, 9 2.7 1.3 0.5 1.0 1.4 0.8 1 I 3.6 2.6 2.1 2, 0 2, 9 Post-emergence test GID50 ratio factor selectivity factors

I A

I A

selectivity

1,691,67

  0.93 0.14 0.16 0.05 0.08 0.04 0.04 0.08 1.10 2.42 0.25 0.41 0.011 0.12 0.11 0.61 0 0.61 0 0.01 0.03 0.02 0.06 0.07 0.06 0.27 0.46 0.07 0.18 0.06 0.015 1.81 12.1, 6. 33.8 21.1 42.3 42.3 21.1 1.5 0.7 6.8 4.1 96.7 14.1 14.2 2.7 8.8 8.0, 7 83.5 27.8 23.9 27.8 6.2 3.6 23.9 9.3 176.2 33.4, 7 1.5 0.7 0.8 1.7 4.0 0.7 0.6 1.3 4.0, 2 3.5 2.3 1.8 2.4 7.5

0 V ...., U UJ

  ralu eUuUU - -m --u, mean value 1.8 2.5 Plant species GID50

I A

  Wheat Co Wo Rg Pa Bt Am Wg St Sw Gg Pp Dn Ck Mw Sp n 1.99 0.60 0.07 0.06 0.02 0.10 0.11 0.48 1.87 0.37 0.15 0.17 1.05 0.59 0.16 0.08 0.02 0.18 0.14 0.18 0.91 0.24 0.10 0.08 O 11%) -4 i It can be seen at From Table 1: 1. The compound according to the invention is more selective than Isoproturon on 9 out of the 12 species of weeds tested in pre-emergence and on 11 of the 15 species of weeds tested in post-emergence. The compound according to the invention is much more active than Isoproturon on commercially important weeds which are quackgrass (perennial grass),

  cleavers and the veronica of Persia.

  3. On average, the compound according to the invention is 1.8 times

  more selective than Isoproturon when applied in pre-

  emergence and 2.5 times more selective than Isoproturon when

is applied in post-emergence.

  Comparative test b) A second test was done in which we compared

  the selective herbicidal activity in wheat of 3- (3-methyl)

  4-isopropylphenyl) -1,1-dimethylurea to that of two other

  commercial herbicides that are derivatives of urea, 3-

  (3-chloro-4-methoxyphenyl) -1,1-dimethylurea (Metoxuron) and the

  3- (3-chloro-4-methylphenyl) -1,1-dimethylurea (Chlortoluron).

  The method applied in this pre-emergence test was identical to that described in the comparative test a)

  above for the pre-emergence test, apart from the modifications

  explicitly stated below. The weed species tested were: quackgrass, Agropyron repen (Co), wild oats, Avena fatua / ludoviciana (Wo), ryegrass, Lolium multiflorum (Rg), annual bluegrass, Poa annua ( Pa), woolly owl, Holcus lanatus (Yo), field foxtail, Alopecurus myosuroides (Am), sugar beet, Beta vugris (Sb), chickweed, Stellaria media (St), Persian veronica , Veronica persica (Sw), Field Bindweed, Convolvulus arvensis (Cv), Persicaria leafless, Polyqonumlapathifolium (Pp), Wild Mustard, Sinapis arvensis (Ck). In this test, treatment results were visually estimated after days and converted to experimental factors. selectivity as described in the comparative test

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  a) above, except that in the present case Chlortoluron was used as the reference compound. In other words, the selectivity factor obtained with each weed species for Chlortoluron was divided by the values obtained for the other two compounds tested, the ratio for Chlortoluron being taken as a unit. The results are given in Table 2 where the compound according to the invention is again called A, Chlortoluron C and Metoxuron M.

TABLE 2

  Species GID50 Selectivity Factor Ratio of Selectivity Plant Factors

C M A C M A C M A

Wheat 2,11 1,54 2,13 - - - -

  Co 1.71 9.23 1.36 1.23 0.48 1.57 1.00 0.39 1.28 Wo 1.58 0.82 0.58 1.34 1, 88 3.67 1.00 1.40 2.74 Rg 0.51 0.49 0.44 4.14 3.14 4.84 1.00 0.76 1.17 Pa 0.19 0.22 0.11 11.11 7.00 19.36 1.00 0.63 1.74 Yo 0.19 0.19 0.14 11.11 8, 11 15.21 1.00 0.73 1.37 Am 0.33 0.87 0.26 6.39 1.77 8.19 1.00 0.28 1.28 Sb 0.54 0.46 0.17 3.91 3.35 12.53 1.00 0.86 3.20 St 0.03 0.03 0.03 70.33 51.33 71.00 1.00 0.73 1.01 Sw 0.45 0.29 0.19 4.69 5.31 11.21 1.00 1.13 2 , 39 Cu 0.25 0.15 4.48 4.44 10.27 0.48 1.00 1.22 0.06 Pp 1.28 0.64 0.90 1, 65 2.41 2.37 1 , 00 1.46 1.44 ck 0.67 0.24 0.10 3.15 6.12 21.30 1.00 2.04 6, 76 Mean value 1.00 0.97 2.04 Fa w re l As shown in Table 2, the compound of the invention

  is on average more than twice as selective as Chlorto

  luron or metoxuron when applied pre-emergence in

wheat.

EXAMPLE 5

  Field evaluation of 3- (3-methyl-4-isopropylphenyl) -1,1-

  dimethylurea. Efficiency and activity spectrum were compared

  post-emergence applications of 3- (3-methyl-4-isopropylphenyl) -

  1,1-dimethylurea and 3- (4-isopropylphenyl) -1,1-dimethyl-

  urea (Isoproturon) in a total of 7 field trials, in winter cereals, in the UK. The trials were conducted in normal commercial winter wheat and winter barley crops where natural infestations

  grasses and / or broadleaf weeds.

  The composition of the compound of the invention, in the form of a suspension concentrate at 500 g / l, was diluted with water, and that of Isoproturon, in the form of a suspension concentrate at 500 g / l (Hytane 500 L). ) and each composition was applied to

  a comparable range of 4 doses for each test. The doses used

  were 1.58 kg / ha, 2.10 kg / ha, 2.63 kg / ha and 4.2 kg / ha of active coefficients of 3/4, 1, 1 1/4 and 2 relative to the recommended commercial dose of 2.1 kg / ha of active substance for Isoproturon applied as a postemergence herbicide to cereals winter, spring. In three trials (# 5, # 6, and # 7), the

  compound of the invention with the addition of a spray adjuvant

  to improve the formulation characteristics. The spray adjunct was applied by mixing it in the container with the compound of the invention, at the rate of 2 parts of

  compound (active substance) per part of spray adjuvant

in weight / volume.

  Plots measuring 10 x 3 m were used and each treatment was repeated three times, in a random distribution. Applications were made to each plot using a small plot gas pressure sprayer, spraying 417 l / ha. Details about the stage of the

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  culture and the conditions of application for each test are

given in Table 3.

  The state of health of the crop has been determined and the effectiveness

  effectiveness of chemical treatment on grasses and bad -

  broadleaf weeds, at a later time from 1 to 3 months to treatment. The effects on the crop were visually estimated using the EWRC scale from 1 to 9, with 0 representing a null effect and 9 representing the destruction of the crop. Weeds were estimated based on the percentage of weed cover, in total and by species, for the predominant weed species found on all test plots. Grassy weeds were assessed by counting the number of panicles in 6 or 8 equal plots, measuring more than 0.5 m and converting these numbers to florets / 0.5 m in each plot. The weed species studied are: a) broadleaf weevil, Persian veronica, Veronica persica (Sw), chickweed

  birds, Stellaria media (St), the matricaria, Matricaria sp.

  (Mw), cleavers, Galiumparin (Gg), purple cutworm, Lamium Durpureum (Dn), b) grasses: field foxtail, Alopecurus mysuroides (Am), wild oats, Avena spp. (Wo). Depending on climatic conditions, harvest was done 138 to 169 days after treatment using a combine and grain weight was determined.

harvest.

  The results of the field trial are shown in Table 4 below. They are expressed as averages for each of the effects determined in the different field trials, which means that the results of all the different field trials were averaged to obtain the mean value in each case. . The effect on culture, as indicated, is the average, on the EWRC scale, of the effective visual estimate made in the seven trials. The values given for the effectiveness against

  weeds are in percent decrease in growth

  sanitary weeds relative to what we get

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  mentioned above. Efficacy values were also noted against all weed species

  in the trial and this average for all species

  these in all trials is indicated under the heading "total dicotyledons" as a percent decrease in growth relative to the control. The weight of the crop is expressed as a percentage of the weight given by the control plots, the control plot being considered as

giving 100%.

TABLE 3

  Culture Variety date of sowing previous year. dated

of applica-

  temperature stage moisture equilibrium culture (legend

--- t

during

of the application

cation, 0C soil,% are worth

to humiliate

  in the soil,% I Winter Wheat Sportsman 26 sppt. Mar. 26 C, D 10.7 27, 1 26.0 34 2 Sonja Winter Barley Oct. 10 28 Feb. A, F 6 28.1 23.5 29 3 Winter wheat Mr. Hobbit 9 Oct. 3 Mar. A, D 5 28.3 31.2 44 4 Hustler Winter Wheat 17 Oct. 3 Mar. A, F 4 , 5 22.3 33.5 41 Flanders Winter Wheat Oct. 3 April A 9, 9 38.6 to 6.1 52 6 Flanders Winter Wheat Il Oct. 3 April C, D, G 10.0 18, 6 16, 9 18 7 Winter Wheat Mitob bit 18 Oct. 3 Apr. B, D 10.0 16.1 16.8 16 j-. 5 open leaves (vegetative stage) B - 6 open leaves (vegetative stage) C - 7 open leaves (vegetative stage) D- main shoot and 2 tillers (tillering stage) E - main shoot and 3 tillers (tillering stage) F - main shoot and 4 tillers (tillering stage) G - pseudostem erection (stage of run) K4 - sj O n test Legend of the stages of cultivation:

ABLEAU 4

Tested compound

3- (3-methyl-4-iso-

propylphenyl) -l, 1-

  dimethylurea 3 (-3-isopropylphenyl) -1,1-dimethylurea Dose Kg / ha of active substance 1,58 2,10 2,63 4,20 1,58 2,10 2,63 4,20 Control effect on culture (EWRC scale) 2,2 2,3 2,2 2,4 2,2 2,1 2,0 2,2 2,6 Effectiveness against weeds Grasses Am Wo 79,1 87,2 93,2 97, 7, 9, 3, 93, 5 97.9 19.4 27.6 33.0 53.2 21.7 34.0 36.1 48.9 Latifolished Sw St Mw Gg Dn

, 3 95.3 93.4 56.0

  , 2, 89.7, 1, 0 43.6 52.9, 98.9 99.6 96.2 97.6 98.8 99.8 94.1 94.5 98, 0, 1 99, 2, 0 87.7, 6 67.0 92.8 8.0 2.5, 3 21.0, 2 53.8 66.8 77.3 49.8 43, 4, 5 72.0 Total

dicoty-

  ledones 82.2, 0, 1 94.4, 1 72.9 73.4 78.7 Weight of the crop as% of control 129.9 138.8 141.8 136.1 134.8 136.6, 1 134.5 Oe r \> 4-E

2'71371

Claims (10)

  1. As a new product, 3- (3-methyl-4-iso) propylphenyl) -1,1-dimethyl urea.   2. Process for obtaining the compound according to the   cation 1, characterized in that it consists in reacting the aniline of formula: CH3 i-C3H7 NH2 or a halohydrate thereof (al either with a dimethylcarbamoyl halide, (b) or with phosgene, to obtain the isocyanate of formula: CH3, <(II)   i-C3H7 i-C H7 QNCO to react at least a portion of the isocyanate with dimethylamine.   3. Method according to claim 2, characterized in that one operates according to (a) in the presence of an agent to eliminate Hydrogen halide.   4. Method according to one of claims 2 or 3, characterized   terized in that it operates according to (a) using chloride of dimethylcarbamoyl.   5. The compound of claim 1 obtained by   method according to any one of claims 2 to 4.   6. Herbicidal composition, characterized in that   comprises the compound according to one of claims 1 or 5 as well as an appropriate support.   7. Composition according to claim 6, characterized in that it comprises at least two supports including at least one is a surfactant.   8. Composition according to one of claims 6 or 7,   characterized in that it also includes one or more   following herbicides: 2- (4-chloro-6-ethyl-amino-5-   triazine-2-yl-amino) -2-methylpropionitrile (Cyanazine), N-benzyl-N- (3,4-dichlorophenyl) -2-aminopropionate   ethyl (benzoylpropethyl), N-benzoyl-N- (3-chloroethyl)   4-fluorophenyl) -2-aminopropionate isopropyl or methyl,   (Flamprop isopropyl and Flamprop methyl).   9. A method for controlling the growth of unwanted plants at a location, characterized in that it consists   to apply a compound according to one of the claims   cations 1 or 5 or a composition according to any one of Claims 6 to 8.   10. Application of a compound according to one of the claims lou 5 as herbicide.