CH645346A5 - 3- (3-METHYL-4-ISOPROPYLPHENYL) -1,1-DIMETHYL URINE, METHOD FOR THE PRODUCTION THEREOF AND HERBICIDES THAT CONTAIN THEM. - Google Patents

Description

The invention therefore relates to the compound of the formula 30 CH-

35

NH - CO - H (CH3) 2

(I)

or a hydrohalide thereof with phosgene to form the isocyanate of formula III

xco

(II) i.e. 3- (3-methyl-4-isopropylphenyl) -l, l-dimethylurea. This compound is particularly suitable for controlling before or after emergence of weeds which grow in crops such as maize, barley or especially wheat. As can be seen from the data given in Examples 4 and 5, this compound has significant advantages over the commercially available herbicide isoproturon for controlling weeds in wheat.

45 The invention also relates to two processes for the preparation of the compound of formula I, which are characterized (III) in that the aniline of formula II or a hydrohalide thereof

CH.

50

and reacting the isocyanate obtained with dimethylamine.

6. A compound of formula I prepared by the process according to claim 2.

7. A compound of formula I prepared by the process according to claim 5.

8. Herbicidal agent, characterized in that it contains the compound of formula I together with at least one carrier.

9. Composition according to claim 8, characterized in

that it contains at least two carriers, at least one of which is a surfactant.

10. Composition according to claim 8 or 9, characterized in that it is one or more of the herbicides 2- (4-chloro - 6-ethylamino-s-triazin-2-ylamino) -2-methylpropionitrile, ethyl-N-benzyl- Contains N- (3,4-dichlorophenyl) -2-aminopropionate or the racemic mixture or (-) isomer of isopropyl or methyl-N-benzoyl-N- (3-chloro-4-fluorophenyl) -2-aminopropionate .

(II)

with a) a dimethylcarbamoyl halide, preferably chloride, or

b) Phosgene (COCl2) with image of the isocyanate of the 60 formula

«IrC3Hf

NC0

(III)

and reacting the isocyanate obtained with dimethylamine.

3rd

645346

Process (a) can be carried out with or without a solvent. Suitable solvents include hydrocarbons and halogenated hydrocarbons, e.g. Benzene, toluene or carbon tetrachloride. This process variant is preferably carried out under essentially anhydrous conditions. Since the reaction is a condensation reaction in which hydrogen halide is eliminated, it is preferably carried out in the presence of a de-hydrohalogenating agent; organic or inorganic bases are suitable; Sodium acetate has been found to be particularly suitable when working without the use of a solvent, and organic bases such as triethylamine or pyrridine are suitable when a solvent is used. The reaction is preferably carried out at a temperature in the range from 0 to 80 ° C., advantageously at room temperature, and the reaction mixture can be worked up by customary methods.

Process (b) is conveniently carried out in the presence of a solvent, e.g. a hydrocarbon such as toluene is carried out at a temperature in the range of 80 to 120 ° C; the reaction can be carried out in a simple manner at the reflux temperature of the solvent used. The resulting isocyanate of the formula III can optionally be isolated from the reaction mixture, but it is preferably reacted in situ with dimethylamine. This reaction is conveniently carried out at a temperature in the range of 0 to 30 ° C, simply at room temperature. The desired product can be isolated in any suitable manner.

The invention further relates to a herbicidal composition which contains the compound of the formula I together with at least one carrier. The invention also relates to a method for controlling weeds with the aid of the compound of the formula I.

In some cases it may be beneficial to mix the compound of the invention with one or more herbicidal compounds, e.g. to change the spectrum of effects. Thus, the compound according to the invention can be mixed with other herbicides with a broad spectrum of activity, such as 2- (4-chloro-6-ethylamine-s-triazin-2-ylamino) -2-methylpropionitrile (trade name "cyano-azine") or with more specific herbicides with a narrower spectrum of activity, such as herbicides against aniline-type oats, as described in GB-PS 1 164 160, for example Ethyl-N-benzyl-N- (3,4-dichloropheniyl) -2-aminopropionate (trade name "Benzoylpropäthyl") and the racemic mixture or (-) isomer of isopropyl or methyl-N - benzoyl-N- (3- chlor-4-fIuorphen, yl) -2-aminopropionate (trade names «Flampropisopropyl» and Flampropmethyl »).

A carrier in an agent according to the invention is any substance with which the active ingredient is prepared in order to apply it to the site to be treated, e.g. a plant, seeds or soil, or to facilitate its storage, transportation or handling. A carrier can be a solid or a liquid including substances which are usually gaseous but have been compressed into a liquid and any carrier used in the preparation of herbicidal compositions can be used in any normal manner.

Suitable solid carriers include natural and synthetic clays and silicates, e.g. natural silica such as diatomaceous earth; Magnesium silicates, e.g. Talke; Magnesium aluminum silicates, e.g. Attapulgite and vermiculite; Aluminum silicates, e.g. Kaolinites, montmorillonites and mica, calcium carbonate, calcium sulfate; synthetic hydrated silicon oxides and synthetic calcium or aluminum silicates; Elements, e.g. Carbon and sulfur; natural and synthetic resins, e.g. Coumarone resin, polyvinyl chloride and styrene polymers and copolymers, solid polychlorophenols, bitumens, washes, e.g. Beeswax, paraffin wax and chlorinated mineral waxes, and solid fertilizers, e.g. Superphosphates.

Suitable liquid carriers include water, alcohols, e.g. Isopropanol and glycols; Ketones, e.g. Acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexa-non; Ether; aromatic or aliphatic hydrocarbons, e.g. Benzene, toluene and xylene; Petroleum fractions, e.g. Kerosene and light mineral oils; chlorinated hydrocarbons, e.g. Carbon tetrachloride, perchlorethylene and trichloroethane. Mixtures of different liquids are often suitable.

15 Agricultural products are often produced in concentrated form, which the consumer then dilutes before application. The presence of small amounts of a carrier that is a surfactant facilitates this process of dilution. Thus, preferably at least one carrier in the agent according to the invention is a surface-active agent. For example, the agent may contain at least two carriers, at least one of which is a surfactant.

25 A surfactant can be an emulsifier, a dispersant or a wetting agent; it can be non-ionic or ionic. Examples of suitable surface-active agents include the sodium or calcium salts of polyacrylic acids and lignin sulfonic acids, the condensation products of fatty acids or aliphatic amines or amides, contain at least 12 carbon atoms in the molecule, with ethylene oxide and / or propylene oxide; Fatty acid esters of glycerin, sorbitol, sucrose or pentaerythritol; Condensates of these substances with ethylene oxide and / or propylene oxide; Condensation products of fatty alcohols or alkylphenols, e.g. p-octylphenol or p-octyl cresol with ethylene oxide and / or propylene oxide; Sulfates or sulfonates of these condensation products; Alkali or alkaline earth salts, preferably sodium salts, of sulfur or sul-40 acid esters containing at least 10 carbon atoms in the molecule, e.g. Sodium lauryl sulfate, sodium sec-alkyl sulfates, sodium salts of sulfonated castor oil and sodium alkyl aryl sulfonates such as sodium dodecylbenzenesulfonate and polymers of ethylene oxide and copolymers of ethylene 45-lenoxide and propylene oxide.

The agents according to the invention can e.g. as usable powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosol. Wettable powders usually contain 25, 50 and 75% by weight of active compound and customarily, in addition to the solid inert carrier, 3 to 10% by weight.

a dispersant and, if necessary, 0 to 10% by weight of stabilizer (s) and / or other additives such as penetrants or tackifiers. Dusts are usually produced as 55 dust concentrates with a composition similar to that of a wettable powder but without a dispersant and are diluted in the field with another solid carrier to an agent which usually contains 0.5 to 10% by weight of active ingredient. Granules are usually produced in such a way that they have a grain size between 0.152 and 1.676 mm and can be produced by agglomeration or impregnation processes. In general, granules contain 0.5 to 25% by weight of active ingredient and 0 to 10% by weight of additives such as stabilizers, 65 modifiers for the slow release of the active ingredient and binder. Emulsifiable concentrates usually contain, in addition to a solvent and, if necessary, cosolvent, 10 to 50% (w / v) active ingredient 2

645346

4th

up to 20% (w / v) emulsifiers and 0 to 20% w / v other additives such as stabilizers, penetrants and corrosion inhibitors. Suspension concentrates are usually composed in such a way that a stable, non-settling, flowable product is obtained and usually contain 10 to 75% by weight of active compound, 0.5 to 15% by weight of dispersant, 0.1 to 10% by weight of suspending agent such as protective colloids and thixotropic agents, 0 to 10% by weight of other additives such as anti-foaming agents, corrosion inhibitors, stabilizers, penetrants and tackifiers and water or an organic liquid in which the active ingredient is essentially insoluble; certain organic solids or inorganic salts may be dissolved in the agent to help prevent settling or as an antifreeze for water.

Aqueous dispersions and emulsions e.g. Agents obtained by diluting a wettable powder or concentrate according to the invention with water are also within the scope of the invention. The emulsions can be in the form of a water-in-oil or an oil-in-water emulsion and have a thick mayonnaise-like consistency.

The agents according to the invention can contain other components e.g. contain other compounds with insecticidal or fungicidal properties.

The invention is illustrated by the following examples.

example 1

Preparation of 3- (3-methyl-4-isopropylphenyl) -1, l-dimethyl-urea

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 dimethylcarbamoyl chloride were added over the course of 15 minutes. The mixture was left to stand at room temperature overnight, then treated with water and then extracted with methylene chloride. After drying over magnesium sulfate, the solvent was evaporated and the resulting solid was recrystallized from a mixture of hexane and toluene.

3.5 g of the desired product, mp 153 ° to 154 ° C., were obtained.

Analysis for C13H20N2O

calcd C 70.9 H 9.1 N 12.7

found C 69.9 H 9.1 N 12.1

Example 2

Alternative process for the preparation of the compound according to the invention

5 g of 3-methyl-4-isopropylaniline (80% pure) in 150 ml of toluene were heated to the reflux temperature while COCl2 gas was bubbled through the solution for approximately 1.5 hours and then dry nitrogen gas to remove excess COCl2. After cooling to 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 the precipitate, 5.5 g of the desired product, was filtered off. After recrystallization from a mixture of hexane and toluene, the desired product had a melting point of 154 ° C.

Example 3

This example shows the preparation of the starting substance 3-methyl-4-isopropylaniline.

186 g of 3-methylaniline were dissolved in 600 ml of sulfuric acid (85% by weight). The mixture was heated to 80 ° C and 120 g of isopropyl alcohol was added. The mixture was stirred at 80 ° C for 6 hours. After this time, the mixture was poured onto ice and ammonium hydroxide was added until the mixture was neutral. Then diethyl ether was added and the ether extract evaporated. The residue 1 was distilled to give 110 g of the desired product, bp 100 ° C. at a pressure of 3.25 mbar.

Example 4

Selective herbicidal activity of the compound according to the invention

Comparative experiment a)

In this experiment, the selective herbicidal activity of 3- (3-methyl-4-isopropylphenyl) -l, l-dimethylurea in wheat was compared with that of the commercial wheat herbicide isoproturon, 3- (4-isopropylphenyl) -l, l-dimethyl urea. The pre-emergence trials were carried out on wheat, Triticum vulgare variety Sappo, and the post-emergence trials were carried out on the Maris Huntsman variety. The weed species examined were: common grasshopper, Agropyron repens (Co); Airport oats, Avena fatua / ludoviciana (Wo); Raygrass, Lolium multiflo-rum (Rg); Annual panicle grass, Poa annua (Pa); Strauss-gras, Agrostis tenuis (Bt); Bulrush, Alopercurus myosuroides (Am); Windstalk, Apera spica venti (Wg); Chickweed, Stellaria media (St); Honorary Award, Veronica persica (Sw); Sticky herb Galium aparine (Gg); Knotweed, polygonum lapathi-folium (pp); red deadnettle, Lamium purpureum (Dn); Field mustard, Sinapis arvensis (Ck); Chamomile, Matricaria spp (Mw); Shepherd's purse ,, Capsella bursa pastoris (Sp); Poppy, Papaver rhoeas (Po).

The active ingredients to be investigated were prepared as emulsifiable concentrates containing 20% by weight of active ingredient, 10% by weight of mineral oil, emulsifiers and xylene as solvents. Each concentrate was diluted with water and the test plants were sprayed with amounts of 6.0, 2.0, 0.6, 0.2, 0.06 and 0.02 kg / ha of active ingredient. Four replicates were performed for each dose and both pre-emergence and post-emergence experiments were performed. Untreated soil in which the seeds were located and untreated soil in which seedlings were found were used as a comparison in the pre-emergence trials. After 21 days in the trial after emergence and 28 days in the trial before emergence, the action of the active compounds was assessed visually on a 0 to 9 scale; a rating of 0 indicates growth as in the untreated comparison and a rating of 9 indicates plant death. In this assessment, an increase of one unit on the linear scale corresponds to an approximately 10% increase in effect.

The results obtained were subjected to probit analysis, with a computer calculating parameters a and b in a relationship of the form:

Probit (percentural response) = a + b log (dose).

With the help of the corresponding curve, the respective doses for a particular response can be calculated. In this example a GID50 value, i.e. the dose required to elicit a 50% drug response for each species.

A selectivity factor for each weed compared to wheat was calculated from the values obtained:

5

10th

15

20th

25th

30th

35

40

45

50

55

60.

65

5

645346

GID50 wheat

Selectivity factor =

GID50 weed

The greater the selectivity factor, the more selectively the herbicide acts.

Finally, the ratio of the selectivity factor for the compound according to the invention to the selectivity factor for isoproturon was calculated. A value of more than 1 indicates that the compound according to the invention acts more selectively than isoproturon. The results are shown in Table I, where the compound of the invention is referred to as A and isoproturon as I.

TABLE I

Plant experiments before emergence Experiments after emergence type GID50 selectivity ratio GID50 selectivity ratio factor the selectivity factor the selectivity

I A I A factor factors I A I A factor factors

Wheat 1.23 1.67 - - - 1.69 1.67

Co

1.99

1.05

0.6

1.6

2.7

0.93

0.61

1.81

2.7

1.5

Where

0.60

0.59

2.1

2.8

1.3

0.14

0.19

12.1

8.8

0.7

Rg

0.07

0.16

17.6

9.3

0.5

0.16

0.21

10.6

8.0

0.8

Pa

0.06

0.08

20.5

20.9

1.0

0.05

0.03

33.8

55.7

1.7

Bt

0.02

0.02

61.5

83.5

1.4

0.08

0.02

21.1

83.5

4.0

At the

0.10

0.18

12.3

9.3

0.8

0.04

0.06

42.3

27.8

0.7

Wg

-

-

-1

-

-

0.04

0.07

42.3

23.9

0.6

St

0.11

0.14

11.2

11.9

1.1

0.08

0.06

21.1

27.8

1.3

Sw

0.48

0.18

2.6

9.3

3.6

1.10

0.27

1.5

6.2

4.0

Gg

1.87

0.91

0.7

1.8

2.6

2.42

0.46

0.7

3.6

5.2

PP

0.37

0.24

3.3

7.0

2.1

0.25

0.07

6.8

23.9

3.5

Dn

0.15

0.10

8.2

16.7

2.0

0.41

0.18

4.1

9.3

2.3

Ck

0.17

0.08

7.2

20.9

2.9

0.011

0.006

96.7

176.2

1.8

Mw

->

-

-,

-

-

0.12

0.5

14.1

33.4

2.4

Sp

0.11

0.015

14.2

105.7

7.5

Po

-

-

-

-

0.001

0.001

- ■

-

-

Average 1.8 2.5

45

Table I shows the following:

1. The compound according to the invention is more selective than 9 of the 12 weed species examined before emergence and 11 of 15 weed species examined after emergence. 50

2. The compound according to the invention is much more effective than isoproturon against commercially important weeds, such as mercury (a perennial grass weed), sticky weed and honorary price.

3. The compound according to the invention is on average 1.8 55 times as selective as isoproturon if it is applied before emergence and 2.5 as selective as isoproturon when applied after emergence.

Comparative experiment b) 60

A second trial was conducted comparing the selective herbicidal activity of 3- (3-methyl-4-isopropyl-phenyl) -l, l-dimethylurea with two other commercial urea herbicides, namely 3- (3 - chlorine -4-methoxyphenyl) -l, l-dimethylurea (chlorotoluron 65) and 3- (3-chloro-4-methylphenyl) -l, l-dimethylurea (metoxuron). The procedure used in this pre-emergence test was the same as described in comparison experiment a) for the pre-emergence experiment with the modifications given below. The types of weeds examined were: common grasshopper, Agropyron repens (Co); Airport oats, Avenafatura / Ludoviciana (Wo); Raygrass, Lolium multiflo-rum (Rg); annual panicle grass, Poa annua (Pa); woolly honey grass, Holcus lanatus (Yo); Bulrush, Alopecurus myosu-roides (Am); Sugar beet, Beta vulgaris (Sb); Chickweed, Stellaria media (St); Honorary Award, Veronica persica (Sw); Field Bindweed, Convolvulus arvensis (Cv); Knotweed, polygonum lapathifolium (pp); Field mustard, Sinapis arvensis (Ck). In this experiment, the results of the treatment were assessed visually after 20 days and, as indicated in comparative experiment a) above, these experimental results were converted into the selectivity factors, with the exception that in this case chlorotoluron was used as the standard. That is, the selectivity factor, as it was obtained for the two compounds to be investigated for the individual weed species, was divided by the selectivity factor for chlorotoluron, the ratio for chlorotoluron was then set to 1. The results are given in Table II, where the compound according to the invention is again referred to as A, chlorotoluron as C and metoxuron as M.

645346

6

TABLE II

Plant GID50 selectivity factor Ratio of selectivity type factors

CMA CMA CMA

Wheat 2.11 1.54 2.13 - - - - - -

Co

1.71

3.23

1.36

1.23

0.48

1.57

1.00

0.39

1.28

Where

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

At the

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

8.44

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 1.00 0.97 2.04

As can be seen from Table II, the compound of the invention is on average more than twice as selective as either chlorotoluron or metoxuron when applied in wheat before emergence.

Example 5

Field evaluation of 3- (3-methyl-4-isopropylphenyl) -l, l - dimethylurea

The efficacy and spectrum of activity of 3- (3-methyl-4-isopropylphenyl) -1, l-dimethylurea after emergence was compared with that of 3- (4-isopropylphenyl) -1,1-dimethylurea (isoproturon) in total 7 field trials in winter crops in the UK compared. The tests were carried out in fields with normal, commercially available winter wheat and winter barley, in which naturally occurring weeds and / or leaved weeds were present.

The preparations of the compound according to the invention in the form of a suspension concentrate containing 500 g / 1 and isoproturon containing 50 g / 1 S.C. (Hytan 500 L) were diluted with water and applied in a comparable amount of four doses for each experiment. Doses of 1.58, 2.10, 2.63 and 4.2 g of active ingredient per hectare corresponded to the%, 1, 1% and 2 times the commercially recommended dose of 2.1 kg / am / ha of isoproturon applied as a post-emergence herbicide to winter cereals in spring. In three experiments (5, 6 and 7), the compound according to the invention was applied with the addition of a spraying aid in order to improve the properties of the agent. The spraying aid was in the form of a mixture with the compound according to the invention in the tank in a ratio of 2 parts of compound (a.m.) to 1 part of spraying aid based on w / v. applied.

Areas of 10 x 3 m were applied and each treatment was carried out 3 times in different random blocks. The compositions were applied to each area using a small area gas pressure sprayer that sprayed a volume of 417 l / ha. Details regarding the state of development of the crop plants and the application conditions for each test are given in Table III.

The health of crops and the effectiveness of chemical treatments against grasses and broad-leaved weeds was assessed one to three months after treatment. The effects on the crop plants were carried out visually according to the EWRC 1-9 scale, the value 0 meaning no effect and the value 9 signifying that the crop plants died off. The evaluation of the weeds includes the estimation of the percentage coverage of broad-leaved weeds in total 35 and of types of the predominant weeds, which were found in all test pieces. The grass weeds were evaluated by counting the panicles in 6 or 8 equal areas of 0.5m + and converting these values into numbers for the single flowers 0.5m in each area. The under-40 weeds searched were: a) broad-leaved weeds - honorary award, Veronica persica (Sw); Chickweed, Stellaria media (St); Chamomile, Matricaria spp. (Mw); Sticky herb, Galium aparine (Gg); red deadnettle, laminium purpurea (Dn) and b) grass weeds - bulrush, Alopecrus myrosuroi-45 des (Am); Airport oats, Avena spp. (Where). Depending on the climatic conditions, the useful plants were harvested 138 to 169 days after the treatment with the aid of a combination harvester and the grain weight of the useful plants was determined.

50 The results of the field tests are given in Table IV below. The values given are mean values for the effects examined in the various field tests, i.e. The mean 55 was calculated in each case from the results for the various field tests. The stated effect on the crop plants is the mean value on the EWRC scale by visual evaluation in 7 experiments. The values given for the activity against weeds refer to the percentage reduction in weed growth compared to the 60 comparison ranges according to the methods given above. The efficacy values against all broad-leaved weed species in the trial are also given and this mean value for all weed species in this trial is given under the heading “Total dicotyledons” 65 as a percentage reduction in plant growth compared to the comparison. The weight of the crops is given as a percentage of the harvest weight of comparison fields, which was set at 100%.

7

645346

TABLE III

Trial No.

Crop

variety

Sowing date (year before)

Application date

Stage of development of

Plants (see below)

Application temperature (° G)

Moisture content (%)

Moisture-equiv-lent

Clay content of

Soil (%)

1

W. wheat

Sportsman

Sept. 26

26th of March

C, D

10.7 °

27.1

26.0

34

2nd

W. barley

Sonja

Oct. 10

Feb 28

A, F

6 °

28.1

23.5

29

3rd

W. wheat

M. Hobbit

October 9

3 March

A, D

5 °

28.3

31.2

44

4th

W. wheat

Hustler

Oct. 17

3 March

A, E

4.5 °

22.3

33.5

41

5

W. wheat

Fl different

October

3rd of April

A

9.9 °

38.6

36.1

52

6

W. wheat

Flanders

Oct. 11

3rd of April

C, D, G

10.0 °

18.6

16.9

18th

7

W. wheat

Mitob bit

Oct. 18

3rd of April

B, D

10.0 °

16.1

16.8

16

Level of development

A - 5 unfolded leaves (seedling)

B - 5 unfolded leaves (seedling)

C - 7 unfolded leaves (seedling)

D - main shoot and 2 stalks (stalk stage)

E - main shoot and 3 stalks (stalk stage)

F - main shoot and 4 stalks (stalk stage)

G - pseudo-stem erection (stem extension stage)

TABLE IV

connection

Dose (kg am / ha)

Efficacy against crops EWRC scale

Grasses at the wo

Efficacy Sw St against weeds broad-leaved weeds Mw Gg Dn

Total-

Dicoty

ledons

Harvest weight (%) based on the

comparison

3- (3-methyl-4-isopropyl

1.58

2.2

79.1

19.4

75.3

95.3

93.4

56.0

65.2

82.2

129.9

pylphenyl (-1, 1-dime-

2.10

2.3

87.2

27.6

80.2

95.5

94.1

70.6

53.8

85.0

138.8

ethyl urea

2.63

2.2

93.2

33.0

85.5

98.9

94.5

67.0

66.8

90.1

141.8

4.20

2.4

97.7

53.2

89.7

99.6

98.0

92.8

77.3.

94.4

136.1

3- (3-isopropylphenyl) -

1.58

2.2

85.9

21.7

45.1

96.2

95.1

8.0

49.8

70.1

134.8

-1.1 -dimethylharn-

2.10

2.1

90.3.

34.0

50.0

97.6

9.2

2.5

43.4

72.9

136.6

material

2.63

2.0

93.5

36.1

43.6

98.8

100.0

20.3

45.5

73.4

130.1

4.20

2.2

97.9

48.9

52.9

99.8

87.7

21.0

72.0

78.7

134.5

comparison

-

2.6

100

Claims (5)

645346 2. A process for the preparation of the compound of formula I, characterized in that the aniline of formula II CH. o> ai) or a hydrohalide thereof with a dimethylcarbamoyl halide. 2nd CLAIMS 1. 3- (3-M ethyl-4-isopropylphenyl) -1,1-dimethylurea of the formula 11. Method for controlling weeds using the compound of the formula I. NH - CO - N (CH3), 3. The method according to claim 2, characterized in that one carries out the reaction in the presence of a dehydro-halogenating agent. 4. The method according to claim 2 or 3, characterized in that dimethylcarbamoyl halide is used as dimethylcarbamoyl chloride. 5. Ancestors for the preparation of the compound of formula I, characterized in that the aniline of formula II An extremely wide class of urea derivatives with herbicidal properties is described in US Pat. No. 2,655,447. In the period of over 25 years since these compounds were made, much research has been done into the use of ureas as herbicides. Probably the most important urea derivative is the compound 3- (4-isopropyIphenyI) -l, l-dimethylurea, which is sold under the trade name «Isoproturon». This compound is widely used in Europe to control i5 weeds in winter cereals. Its main advantage is that it is extremely effective against a variety of weeds and can be used both as a pre-emergence and as a post-run herbicide, both in autumn and spring. Its main disadvantage is that some economically important weeds, in particular perennial broadleaf weeds, perennial weeds, sticky weed and special price, are not controlled. It has now been shown that a certain phenyl urea-25 derivative, which is not expressly mentioned in US Pat. No. 2,655,447, in which the phenyl ring has two special substituents, has particularly favorable herbicidal properties.