DE3319557A1 - UREA COMPOUNDS AND THEIR USE AS HERBICIDES - Google Patents

Description

BERG ■ STAPPI: i £. . ^^^

MAUcRKlRCHERSTRASSE 45 8000 MUNICH 80

Attorney's files: 32 772 & * May 30, 1983

VELSICOL CHEMICAL CORPORATION CHICAGO, ILL. 60611 / USA

New urea compounds and their use as herbicides

mnq \ 98 82 72 - 74 Telex OS 24 560 BERG d Bank accounts: Bayei. Veieinsbank Munich 453100 (BLZ 700 2C2 70)

- - ti · - - η -, - υ »<(...-» «." jjiini '^ i 7 70020011) Swift Code HYPC

- h-

B e s c h r e i b u η

The invention relates to new chemical preparations, in particular it relates to new urea compounds of the formulas

CH ₃

H-C-C "- * ι CH,

H 0 CH,

I Il I ³

-NCN-CH ₂ -CH

C I

or

CH ₃

HC-C-

³ I.

CH ₁

H 0 CH, / ^C

INI ³ / -NCN-CH ₇ -CH

CCH ₂ ) n -C

where R is lower alkyl, η is zero or 1 and m is zero or an integer Number from 1 to 6 mean.

The preferred compounds have the structural formula

CH ₃

HC-C ° ι CH-,

H 0
I Il
NCN-CH ₂ -CH

CCH ₀ ) η

V-U

The compounds of the invention are particularly useful as herbicides. _ / ₄

-Mr-

As used herein, "low" means a straight or branched carbon chain of up to six carbon atoms .

The compounds according to the invention can by reaction a compound of the formula

O = C = N "

CH., Ι ^ύ

C- CH

CH,

OC-N-

CH ₃

1-C-CH ₃ CH ₃

with two moles of an amine of the formula

J o

(III)

, 0

N-CH ₂ -CH

CH-

getting produced.

(IV)

- / 5

--ι

This reaction can be effected by placing a mixture of the isocyanate dimer and the amine in an inert reaction medium like toluene heated with stirring until the reactants dissolve. The product can then be processed using standard procedures for removal of the solvent and also further purified using standard procedures.

The isocyanate dimer of the formula III can by reacting a Compound of formula

NHr CH,

CH-I

H ₃ CCJ I
CH.

or

V- "

HCC I

be prepared with phosgene in a molar excess.

This reaction can be carried out by adding a slurry or Solution of the compound of formula V in a suitable organic solvent such as toluene to a saturated Phosgene solution in an organic solvent such as toluene. The resulting mixture can be stored at ambient temperatures be stirred for about U up to 24 h. This reaction mixture can then be purged with nitrogen gas, i.e. unreacted phosgene is removed; it is then filtered when the desired product appears as a precipitate forms, or evaporates when the product is dissolved. It can be used as-is or further purified will.

In the following examples, the preparation of the invention Connections shown.

example 1

Preparation of 5-tert-butylisoxazol-3-yl isocyanate dimer A solution of 12% phosgene in 80 ml of toluene was placed in a glass reaction vessel that was connected to a mechanical

- / 6

me *

P * 9

Agitator was equipped. A 4 g slurry 5-tert-Butyl-3-aminoisoxazole in 20 ml of toluene was added to the Given reaction vessel, and the resulting reaction mixture was stirred for about 16 hours which resulted in the formation of a precipitate. The reaction mixture was then used to remove Purified unreacted phosgene with nitrogen gas. The purified mixture was filtered off to obtain the desired one te product 5-tert. -Butylisoxazol-S-yl-isocyanatdiiner as a solid.

Example 2 *

Production of 1- (5-tert-butylisoxazole-S-yD-S-methyl-S- (1,3-dioxolan-2 ~ ylmethyl) urea

A mixture of 5 g of 5-tert-butylisoxazol-S-yl-isocyanatdiner, 4 g of N- (1,3-dioxolan-2-ylmethyl) -methylamine and 100 ml of toluene was placed in a glass reaction flask with a mechanical stirrer and thermometer was equipped. The reaction mixture was then heated with stirring until the reactants dissolved. The solvent was then removed from the reaction mixture and the residue was recrystallized from ethyl acetate; the desired Frodukt was obtained as a solid, mp 130-131 ⁰ C. Elemental analysis:. CHN

0.

Calculated: 55.11 7.47 14.83

Found: 54.36; 54.56 7.47; 7.48 14.45; 14.52

Example 3

Preparation of 1- (5-tert-butylisoxazol-3-yl) -3-meth / l-3- (1,3-dioxan-2-ylmethyl) urea

A mixture of 5 g of 5-tert. -Butylisoxazol-3-yl ~ isocyanatdiir.er, 4.5 g of N- (1,3-dioxan-2-ylmethyl) methylamine and 100 ml of toluene was placed in a glass reaction flask with mechanisehem Agitator and thermometer given. The reaction:; mixed

-11

* ft

- fir-

then heated with stirring until the reactants dissolved. To the reaction mixture were added 50 ml of hexane, the desired product was recovered as a precipitate, mp. 171-173 ⁰ C.

Elemental analysis: CHN

Calculated: 56.55 7.8 14.13

Found: 55.79; 55.96 7.8; 7.94 13.85; 13.96

Exemplary compounds according to the invention, which with the in The methods described above are:

1- (3-tert-Butylisoxazol-5-yl) -3-methyl-3- (1,3-dioxolan-2-ylmethyl-urea

1- (3-tert-Butylisoxazol-5-yl) -3-methyl-3- (1,3-dioxan-2-y 1-rae thyI) urea

1- (5-tert-Butylisoxazol-3-yI) -3-methyl-3- (4,5-dimethyl-1,3-dioxolan-2-ylmethyl) urea

1- (5-tert-Butylisoxazol-3-yI) -3-methyl-3- (4,5,6-triethy1-1,3-dioxan-2-ylmethyl) urea

1- (3-tert -Butylisoxazol-5-yl) -3-methyl-3- (4-hexy1-1,3-dioxolan-2-ylmethyl) urea

1- (3-tert-Butylisoxazol-5-yI) -3-methyl-3- (5,6-dipenty1-1,3-dioxan-2-ylmethyl) urea

1- (5-tert-Butylisoxazol-3-yI) -3-methyl-3- (4-isopropy1-1,3-dioxolan-2-ylmethyl) urea

1- (S-tert-butylisoxazol-3-yl) -3-methyl-3- (4,5-dibutyl-1,3-dioxan-2-ylmethyl) urea

1- (3-tert-Butylisoxazol-5-yI) -3-methyl-3- (5-penxy1-1,3-dioxolan-2-ylmethyl) urea

1- (3-tert-Butylisoxazol-5-yI) -3-methyl-3- (4-methyl-5-ethyll, 3-dioxan-2-ylmethyl) urea

1- (5-tert-Butylisoxazol-3-yI) -3-methyl-3- (4-ethyl-S-propy1-1,3-dioxolan-2-ylmethyl-urea

1- (5-tert-Butylisoxazol-3-yI) -3-methyl-3- (4-ethy1-5,6-diisopropyl-1,3-dioxan-2-ylmethyl) urea _{/ g}

A # Ii a «

# e> β η # ο

• Φ * * β ο

1- (3-tert -Butylisoxazol-5-yl) -3-methyl-3- (4-hexyl-5-pentyl-1,3-dioxolan-2-ylmethyl) urea

1- (3-tert-Butylisoxazol-5-yI) -3-methyl-3- (5-butyl-S-propy1-1,3-dioxan-2-ylmethyl) urea.

- / 9

For practical use as herbicides, the inventively * compounds according to the invention are generally included in herbicide preparations which have an inert carrier and a herbicide contain a toxic amount of such a compound. With such herbicide preparations or formulations, the active ingredient can conveniently be applied at the location of the weed infestation in any desired amount. These preparations can contain solids like Dusts, granules or wettable powders, or liquids such as solutions, aerosols or emulsifiable concentrates.

Dust can, for example, by grinding and mixing the Active ingredient with an inert solid carrier such as talc, clay, silica, pyrophyllite and the like. Be prepared. Granulate preparations can be prepared by dissolving the compound usually dissolved in a suitable solvent and impregnated in granulated carriers such as attapulgites or vermiculites having a particle size of usually about 0.3 to 1.5 mm. Wettable powders that can be dispersed in water or oil to give any concentration of active ingredient, can be produced by incorporating wetting agents in concentrated dust preparations.

In some cases the active ingredients are sufficiently soluble in common organic solvents such as kerosene or xylene, so that they can be used directly as solutions in these solvents. Often herbicide solutions can be found under Overpressure can be dispersed as aerosols. As liquid herbicide preparations however, emulsifiable concentrates are preferred which contain an active ingredient according to the invention and are inert Carriers contain a solvent and an emulsifier. Such emulsifiable concentrates can be mixed with water and / or oil can be diluted to any desired concentration of active ingredient for application as a spray to the location of the weed infestation.

The most common emulsifiers used in these concentrates

- / CO -

- n-

nonionic or mixtures of nonionic and anionic Surfactants used. When using certain emulsifying systems can be an inverted emulsion (water-in-oil) for the direct application to the weeds.

A typical herbicide extension according to the invention is shown in FIG the following example, the quantities are parts by weight.

Example U

Making a dust

Product according to example 2 10
Powdered Talc 90

The ingredients are ground in a mechanical mixer mill, until a homogeneous, free-flowing dust with the desired particle size is obtained. This dust can be directly on the The location of the weed infestation.

The compounds of the present invention can be used as herbicides by any known method. With one of these Method of weed control is the weed location with a herbicide preparation, which is an inert carrier and, as essential active ingredient, a compound according to the invention in an amount which is herbicidally toxic to the weeds contains, treated. The concentration of the new invention Compounds in the herbicidal preparation largely depend on the type of formulation and the intended use, in general However, the herb extracts contain about 0.05 to 95% by weight of the active ingredient according to the invention. In a preferred Embodiment of the invention contain the herbicide preparations about 5 to 75% by weight of active ingredient. The preparations can also contain other substances such as other pesticides, e.g., insecticides, nematicides, fungicides and the like; also stabilizers, distributors, activators, deactivators, adhesives and adhesives, fertilizers, synergists, etc. - / Ii

The compounds of the invention are those described above Herbicidal preparations can also be used in conjunction with other herbicides and / or defoliants, siccators, growth inhibitors and the like. These other substances can be around Make up 5 to 95% of the active ingredients in the herbicide preparations. The use of combinations of these other herbi- * cides and / or defoliants, desiccators, etc., with the compounds according to the invention results in herbicide preparations = « which are more effective for weed control and often produce results with separate formulations of each Herbicides cannot be achieved. To the other herbicides, defoliants, desiccators and plant growth inhibitors, with which together the compounds according to the invention In the herbicide preparations that can be used for weed control include: Chlorophenoxy herbicides such as 1, U-D, 1,4,5-T, MCPA, MCPB, 4 (2, U-DB), 2, U-DEB, U-CPB, U-CPP, 2,4,5-TB, 2,4,5-TES, 3, U-DA, Silvex and the like j carbamate herbicides such as IPC, CIPC, Swep, Barban, BCPC, CEPC, CPPC and the like; Thiocarbamate and dithiocarbamate herbicides such as DCEC, sodium methane, EPTC, Dialat, PEBC, Perbulat, Vemolat and the like; substituted urea herbicides such as norea, siduron, dichloral urea, Chloroxuron, Cycluron, Fenuron, Monuron, Monuron TCA, Diuron, Linuron, Monolinuron, Neburon, Buturon, Trimeturon and the like; symmetrical triazine herbicides such as simazine, chlorazine, atraon, desmetryn, norazin, ipazin, prometryn, Atrazine, trietazine, simetone, prometon, propazine, ametryn, and the like; Chloracetamide herbicides such as a-chlorine-N, N-dimethylacetamide, CDEA, CDAA, a-chloro-N-isopropy! Acetamide, 2-chloro-N-isopropyl-acetanilide, U- (chloroacetyl) -morpholine, l- (chloroacetyD-piperidine and the like; chlorinated aliphatic acid herbicides such as TCA, Dalapon, 2,3-dichloropropionic acid, 2,2,3-TPA and the like; chlorinated benzoic acid and phenylacetic acid herbicides such as 2,3,6-TBA, 2,3,5,6-TBA, dicamba, tricamba, Amiben, Fenac, PBA, 2-methoxy-3,6-dichlorophenylacetic acid, 3-methoxy-2,6-dichlorophenylacetic acid, 2-methoxy-3, U, 6-trichlorophenylacetic acid, 2, U-dichloro-3-nitrobenzoic acid and

- / 12

• · · 1

like; as well as compounds such as aminotriazole, maleic hydrazide, Phenyl mercury acetate, endothal, biuret, technical chlordane, Dimethyl-2,3,5,6-tetrachloroterephthalate, Diquat, Erbon, DNC, DNBP, dichlorbenil, DPA, diphenamide, dipropalin, trifluralin, Solan, Dicryl, Merphos, DMPA, DSMA, MSMA, Potassium Acid, Acrolein, Benefin, Bensulid, AMS, Bromacil, 2- (3,4-dichlorophenyl) -4-methyl-l, 2,4-oxadiazolidine, 3,5-dione, bromoxynil, cacodylic acid, DMA, DPMF, cypromid, DCB, DCPA, dichlone, Diphenatril, DMTT, DNAP, EBEP, EXD, HCA, Iosynil, IPX, Is ocril, Potassium cyanate, MAA, MAMA, MCPES, MCPP, MH, molinate, NPA, OCH, Paraquat, PCP, Picloram, DPA, PCA, Pyrichlor, Seson, Terbacil, Terbutol, TCBA, Brominil, CP-501im, H-176-1, H-732, M-2091, Planavin, sodium tetraborate, calcium cyanamide, DEF, Ethylxanthogendxsulfid, Sindon, Sindon B, Propanil and the like.

These herbicides can in the inventive method and Preparations can also be used in the form of their salts, esters, amides and other derivatives, provided this is applicable to the respective Connection is possible.

Weeds are undesirable plants with no economic value that the production of crops, the growth of Ornamental plants or disturb the health of livestock. Many types of weeds are known, such as annual weeds such as Chenopodium, Chenopodium album, Foxtail, Digitaria sanguinalis, wild mustard, cotyledon umbilicus, lolium, bedstraw, chickweed, wild oats, Abutilon theophrasti, purslane, Echinocloa crus-galli, Polygonum sp., knotweed, xanthium pensylvanicum, wild buckwheat, Kochia, Medicago, Kornrade, Ambrosia, Sonchus, coffee herb, Croton, Cuphea, hop silk, Ground smoke, ragwort, Galeopsis, Knowel, milkweed, sparrow, Emex, Panicum colonum, Laichkraut, Anthemis cotula, Mollugo verticillata, Ipomoea, Galium, and duckweed; biennial weeds such as wild carrot, matricaria, wild barley, light carnation, Chamomile, Burdock, Mullein, Mallow, Cirsium anceolatum, Dog's Tongue, Verbascum Blattaria, and Crimson

Star thistle; as well as perennial weeds such as white wheels, Agropyrum repens, Sorghum halepense, Cirsium arvense, hedgehog, Cynodon dactylon, Rumex acetosella, dock, dandelion, Bellflower, bindweed, Centaurea, Prosopis juliflora, toadflax, Yarrow, aster, lithospermum, horsetail, Vemonia, Sesbania, bulrush, Typha latifolia and Barbarea.

These weeds can also be called broad-leaved or grassy Weeds are classified. For economic reasons it is desirable to keep such weeds under growth Maintain control without harming crops or livestock.

The new compounds of the invention are for weed control particularly useful because they are toxic to many species and groups of weeds, but relatively toxic to many crops are non-toxic. The exact amount of compound needed will depend on a number of factors including the Resistance of the respective weed species, the weather, the soil type, the application method, the type of crops in the same area and the like. For example, the application of only about 70 to IUO g / ha of active ingredient can effectively combat a light infestation with weeds growing under adverse conditions is sufficient while about 10 or more kg / ha Active ingredient may be necessary when it comes to combating a dense infestation with resistant perennials Weeds that thrive in favorable circumstances.

The herbicidal toxicity of the new compounds according to the invention can be determined using many known and recognized test methods, such as pre-emergence and post-emergence tests are presented.

The herbicidal activity of the compounds according to the invention was illustrated with experiments necessary for pre-emergence control a number of weeds were carried out. Here, plastic greenhouse pots became completely drier

• ♦ · t

Sown earth with the various weed seeds. After 2 o'clock or less, the pots were sprayed with water until the soil was wet and the test compounds made up as aqueous Emulsions of acetone solutions with emulsifying agents were used sprayed onto the surface of the earth in the specified concentrations.

The containers were then placed in the greenhouse and heated and watered as required. The plants were Maintained under these conditions for 14 to 21 days, then was the degree of damage to the plants classified on a scale from 0 to 10:

0 = no damage, 1.2 = slight, 3, U = moderate, 5.6 = moderately severe, 7,8,9 = severe damage and 10 = dead, NE means "no emergence". The effectiveness of the Connections can be seen from the following information:

- / 15

Pre-emergence herbicide test 11 days after treatment, product according to Example 2

Application rate kg / ha

Wild mustard Convolvulvus Chenopodium

Abutilon theophrasti

Ipomoea

Yellow foxtail

Echinocloa crus-galli Sorghum halepense Agropyrum repens Wild oats

Digitaria sanguinalis

Sprangletop False Grain (Cheat Grass)

Sugar beet soy beans cotton pinto beans alfalfa

wheat

rice

Sorghum

Corn

oats

1.1 0.56 0.28 0.14 10 1 10 5 8th 5 5 4th 8th • 0 0 0 8th 0 0 0 10 10 8th 8th 7th 3 3 0 9 0 0 0 8th 8th 7th 8th 3 1 0 0 7th 4th 3 0 9 9 8th 8th 9 9 8th 5 0 0 0 0 10 0 10 10 7th 3 2 2 NE 0 0 0 0 0 0 0 10 10 10 5 5 0 0 0 10 8th 7th 7th 8th 7th 2 2 6th 5 3 0 5 7th 0 0

- / 16

I ft

Pre-emergence herbicide test 21 days after treatment, product according to Example 2

Application rate kg / ha

Wild mustard convolvulvus Chenopodium

Abutilon theophrasti

Ipomoea yellow foxtail

Echinocloa crus-galli Sorghum halepense Agropyrum repens Wild oats

Digitaria sanguinalis

Sprangletop False Grain (Cheat Grass)

Sugar beet soybeans cotton pinto beans alfalfa wheat

rice

Sorghum corn

oats

0.56

0.28

0.14

10 3 10 7th 10 0 0 0 10 10 10 0 10 2 9 1 10 10 10 7th 10 0 0 . 0 10 0 0 0 9 8th 5 3 5 8th 0 0 10 10 8th 0 10 10 8th 0 10 10 9 0 8th 8th 1 0 10 10 10 10 10 3 2 0 NE 0 0 0 9 10 0 0 10 10 10 0 10 10 5 0 10 10 U 2 8th 8th 1 0 7th 8th 0 0 10 10 1 0

- ZT -

Pre-emergence herbicide test IU days after treatment, product according to Example 3

Application rate kg / ha

Cyperus esculentus Wild mustard Convolvulvus Chenopodium

Datura
stramonium

Ab ut i lon theophrasti

Ipomoea

Yellow foxtail

Echinocloa crus-galli Sorghum halepense Agropyrum repens Wild oats

Digitaria sanguinalis

SprangIetop Wrong Grain (Cheat Grass)

Sugar beet soy beans cotton pinto beans alfalfa

wheat

rice

Sorghum

Corn

oats

4.5 2.2 1.1 0.56 0.28

1
10

10
4th
4th

8th
6th

7th
7th

10
10

10

3
2
3
7th

5
9

10

10
1

10
10
0
2
2
7th

10
10
10

10

10
1

0
0
2
0

10
0

10
0

10
10
0
0
0
0

10 10

9 8 0

0 0 3 0

0 0

10 0

10 0

10 0 0 0 0 0

0.14

2 3 0

1 2 0

0 0 0 0

10 0 9 0

10 0 0 0 0 0

Pre-emergence herbicide test

21 days after treatment 0.56 0.28 0.1 product according to Example 3 - - Application rate
kg / ha 2.2 1.1 10 10 10 Cyperus esculentus 3 2 2 10 10 7th Wild mustard 10 10 10 10 10 0 Convolvulvus - - 10 10 10 10 Chenopodium 7th 8th 8th 10 10 10 Datura
stramonium 10 10 5 10 10 10 Abutilon
theophrasti 10 10 10 1 0 0 Ipomoea 10 10 10 1 0 0 Yellow foxtail 10 10 10 2 0 0 Echinocloa
crus-galli 10 10 8th 10 7th 0 Sorghum halepense 7th 8th 7th 1 1 0 Agropyrum repens - - 10 0 0 0 Wild oats 10 10 10 7th 0 0 Digitaria
sanguinalis 10 10 10 9 0 0 Sprangletop - - 10 10 10 10 Wrong grain
(Cheat Grass) 10 9 10 4th 1 Sugar beet - - 10 10 10 10 Soybeans - - 10 8th 7th 0 cotton - - 10 10 10 10 Pinto beans - - 10 10 3 1 alfalfa - - 10 0 0 0 wheat - - 10 1 0 0 rice - - 10 3 0 0 Sorghum - - 10 4th 0 0 Corn - - 10 oats _ _ 10

- / 19

The herbicidal activity of the compounds according to the invention was also shown with experiments> those for post-emergence control a number of weeds were carried out. The connections to be tested were saved as Prepared aqueous emulsions and sprayed them on the leaves of various types of weeds at the specified dosage reached a specified size. After spraying, the plants were placed in a greenhouse and daily or watered more often. No water was placed on the foliage of the treated plants. The severity of the injury was 14 days determined after treatment and classified from 0 to 10 as defined above. The effectiveness of these compounds reveals from the following information:

- / 20

10 10 10 10 10 10 10 10 mm 10 10

Post-emergence herbicide test product according to Example 2

Application rate

kg / ha 1.1 0.56 0.28 0.1t

Wild mustard Convolvulvus Chenopodium Datura

stramonium 10 10 10 10

Abutilon theophrasti

Ipomoea

Yellow foxtail

Echinocloa crus-galli Sorghum halepense Agropyrum repens Wild oats

Digitaria sanguinalis

SprangIetop Wrong Grain (Cheat Grass)

Sugar beet cotton soybeans pinto beans alfalfa

Sorghum

wheat

rice

Corn

oats

10 10 10 10 10 10 10 10 8th 9 5 0 10 10 0 0 10 10 1 0 10 10 10 0 10 10 10 2 10 8th 0 0 10 10 10 1 10 8th 0 0 10 10 10 10 10 10 10 10 10 10 7th 6th 10 10 10 7th 10 10 10 10 10 3 0 0 10 10 10 5 10 10 10 1 10 7th 0 0 10 10 9 1

- / 21

Post-emergence herbicide test Product according to example 3

Application rate **, 5 2.2 1.1 0.56 0.28 o, m 0.07 0.035 kec / ha 10 7th 8th 10 10 10 - - Cyperus esculentus 10 10 10 - - 10 0 0 Wild mustard 10 7th 7th 10 7th 0 0 0 Convolvulvus 10 10 10 10 10 10 - - Chenopodium Datura 10 10 10 10 10 10 - - stramonium Ab ut i lon ■ " _ 0 0 theophrasti 10 10 10 10 10 10 0 0 Ipomoea 7th 10 9 10 0 0 - - Yellow foxtail Echinocloa 10 10 7th 10 10 0 0 0 crus-galli 10 8th 10 10 0 0 0 0 Sorghum halepense - - 7th 7th 0 0 - Agropyrum repens 10 10 10 1 0 0 - - Wild oats Digitaria 10 10 10 5 0 0 sanguinalis - - 10 7th 0 0 - - Sprangletop Wrong grain 3 1 0 0 (Cheat Grass) - - 10 10 10 10 - - Sugar beet - - 10 10 10 10 - - cotton 10 10 10 9 1 1 0 0 Soybeans - - 10 10 10 0 - - Pinto beans - - 10 10 10 10 - - alfalfa - - 10 1 0 0 - - Sorghum - - 10 10 0 0 - - wheat - - 0 0 0 0 - - rice - - 10 1 1 0 - - Corn - - 10 5 0 0 - - oats

Claims (6)

• * ft at the ο BERG ■ STAPF. ^: \ 2CHWÄB £ ^: * PATENT LAWYERS MAUERKIRCHfcRSTRASSE 45 8000 MUNICH 80 Attorney's file: 32 772 Claims 1 .j compound of formula H H 0 CH- / ° NCN-CH ₂ -CH HC-C ^J ι CH-, or CH- CH. H 0 CH, / ° I Il I ³ / NCN-CH ₇ -CH where R is lower alkyl, η is zero or 1, and m is zero or one an integer from 1 to 6. 2. Compound of formula HC-c ° ι CH- Il 0 CH-Z / ^L Il I / NCN-CH ₂ -CH 0 ' (CH ₂ ) n - / 2 3. A compound according to claim 2, characterized that they are l- (5-tert-butylisoxazol-3-yl) -3-methy1-3- (1,3-dioxolan-2-ylmethyl) urea is. 4. A compound according to claim 2, characterized that they are l- (5-tert-butylisoxazol-3-yl) -3-methyl-3- (1,3-dioxan-2-ylmethyl) urea is. 5. Herbicide preparation, characterized in that it has an inert carrier and, as essential component containing a compound according to claim 1 in an amount toxic to weeds. 6. A method for combating weeds, characterized that the weeds are brought into contact with the herbicide preparation according to claim 5, - / 3