DE1542834B1 - N-phenyl-N'-hydroxyurea esters and their use as herbicides - Google Patents

Description

It is known to use trisubstituted ureas, e.g. B. N-p-chlorophenyl-N ^ N'-dimethylurea, as herbicidal Use active ingredients. However, their effect is not satisfactory.

It has been found that N-phenyl-N'-hydroxyurea esters of the general formula The residue is recrystallized from toluene-petroleum ether. 21 parts by weight of N-3,4-dichlorophenyl - N '- methyl - N' - (2,4 - dichlorophenoxyacet) oxyurea are obtained the structural formula

, CH,

/ CH ₃ NH-CO-N <Cl

-NH-CO-N

- R ίο

in which X ₍ "= d represents a fluorine, chlorine or bromine atom, a trifluoromethyl or nitro group in the 3- or 4-position or X _{(n = 2)} chlorine atoms in the 3,4-position and R represents a dimethylamine , i-propyl, isopropenyl, 2-chloro-n-butyl- (2) -, bromot-butyl-, 3-n-heptyl, cyclopropyl or 2,4-dichlorophenoxymethyl radicals, has a rapid onset of action and a good one show herbicidal effect on weeds and grass weeds.

The active ingredients can be prepared in a manner known per se by reacting substituted N-phenyl-N'-hydroxyureas with acid halides or carbamic acid halides in the presence of alkaline agents, the N-phenyl-N'-hydroxyureas on their part z. B. from the corresponding isocyanates and substituted hydroxylamines can be produced.

The following production processes explain the production of the new substituted urea derivatives.

For example

To 12 parts by weight of N - 3,4 - dichlorophenyl-N'-methyl-N'-hydroxyurea, dissolved in 75 parts by weight of toluene and 5.2 parts by weight of triethylamine, 5.4 parts by weight of dimethylcarbamic acid chloride are added dropwise at 35 ° C. with stirring. Afterward the reaction mixture is kept at 60 to 65 ° C for a few hours. After cooling it will the mixture washed with water, dried and freed from the solvent in vacuo. The crystalline residue is recrystallized from toluene. 14 parts by weight of N-3,4-dichlorophenyl-N'-methyl-NHdimethylcarbamoyi) oxyurea are obtained the structural formula

from F. 115 to 117 ⁰ C.

Chlorine found 32.4%, calculated 32.4%.

The other active ingredients can be produced by appropriate processes. The reaction temperature in the esterification can lie, depending on the kind of the acid halide or Carbaminsäurehalogenids used between -20 and +100 ⁰ C, but preferably between 0 and 70 ° C.

The following substances are mentioned as compounds according to the invention:

NH-CO-N

/ CH,

-0-CO-N

/ CH,

from 134 to 136 ° C.
Chlorine found 23.6%, calculated 23.2%.

Ice pie 12

To 12 parts by weight of N - 3,4 - dichlorophenyl- ■ N'-methyl-N'-Hydrojcyjiarnstqff, dissolved in 75 parts by weight Toluene and 5.2 parts by weight of triethylamine, 12 parts by weight are added dropwise with stirring at 20.degree.-30.degree 2,4-dichlorophenoxyacetic acid chloride, dissolved in 10 parts by weight of toluene. Then will the reaction mixture for a few hours at 40 held up to 45 ° C. After cooling, the mixture is washed with water, dried and im Freed from solvent in vacuo. The crystalline one

X 35 ' 4-Br 40 3-Cl 45 3-NO ₂ 3-CF ₃ η R. ^ CH ₂ - N / CH ₃ ^ CH ₃ CP 3 F. ° C / CH ₂ / CH ₃ -CH - CH- (CH ₂ ) ₃ - CH ₃ 3,4-Cl 1 -CH C ₂ H ₅ 92 to 94 -C = CH ₂ - 55 4-Br CH ₃ 1 C. 104 to 106 60
3,4-Cl : h ₃
: —CH ₂ Br i CH ₃ 78 to 80 65 / CH ₃ 2 - N 63 to 65 1 80 to 82 2 92 to 94 1 90 to 92

GBIGSMAL INSPECTED

continuation

X 1 R. ^X CH ₃ ^ CH ₃ F. ° C / CH ₃ / CH ₃ / CH ₃ 4-F - N -CH -CH
^ CH ₃ 98 to 100 1 Cl ζ
( 4-Br - C ₂ H ₅
: h ₃ 65 to 67 2 3,4-Cl 2 Kp-0.5 =
77 to 80 3,4-Cl Kp-0.5 =
102 to 104

The compounds according to the invention can be used as solutions, emulsions, suspensions or dusts be applied. The forms of application depend entirely on the intended use; they should ensure a fine distribution of the active substance in each case.

However, the compounds according to the invention can also be used with other herbicides, e.g. B. triazines, dichloroalkylcarboxylic acid derivatives, Urea, uracil or pyridazone are used together.

The following experiments explain the use of the herbicides according to the invention.

In the greenhouse, plastic pots 8 cm in diameter were filled with loamy sand soil and with seeds of Gossypium spp. (Cotton), Zea mays (maize), Hordeum vulgare (barley), Triticum vulgar (wheat), Sinapis arvensis (field mustard), Chenopodium album (white goose foot), Urtica urens (small nettle), Stellaria media (chickweed), Galinsoga parviflora (French herb), Poa annua (annual bluegrass) and Alopecurus myosuroides (black foxtail) sown. Subsequently was the prepared soil with N-3,4-dichlorophenyl-N '- methyl - N' - (dimethylcarbamoyl) - oxyharnst off (I), N - 3,4 - dichlorophenyl - N '- methyl - N' - (2,4 - dichlorophenoxyacetate) oxyurea (II) and in comparison with N-p-chlorophenyl-N'jN'-dimethylurea (III) each at an application rate of 3 kg of active ingredient per hectare dispersed in 500 l of water, treated. After 3 to 4 weeks it was found that the compounds I and II compared to III an approximately equally good herbicidal effect, but better compatibility with cotton, maize, barley and own wheat. The test results can be seen from the table below.

Crops I. Active ingredient
II III cotton 0
0 0
0 10-20
20th Corn 10
5 5
0-5 30-40
40-50 barley wheat 90-100
90-100
100
90-100
90-100
90
80-90 90-100
90-100
100
90-100
90-100
85-90
80-90 100
90-100
100
90-100
90-100
90
80-90 Unwanted plants Mustard White goosefoot
Small stinging nettle
Chickweed French herb Annual bluegrass
Black foxtail ....

0 = without damage.
100 = total damage.

In the greenhouse, the plants were Zea mays (maize), Hordeum vulgare (barley), Triticum vulgare (Wheat), Seeale cereale (rye), Sinapis arvensis (field mustard), Chenopodium album (white goose foot), Urtica urens (small nettle), Bidens pilosa (two-toothed teeth), Kochia scoparia (broomstick), Avena fatua (Wild oats), Poa annua (annual bluegrass) and Alopecurus myosuroides (black foxtail) at a height of 4 to 17 cm with N - 3,4 - dichlorophenyl - N '- methyl - N' - (dimethylcarbamoyl) oxyurea (I), N-3,4-dichlorophenyl-N '- methyl - N' - (2,4 - dichlorophenoxyacet) - oxyurea (II), N-3,4-dichlorophenyl-N'-methyl-N '- (isobutyryl) - oxyurea (III), N - 3,4 - dichlorophenyl-N' - methyl - N '- (2 - chloro - 2 - methylbutanoyl) - oxyurea (IV) and in comparison with this with N-p-chlorine- phenyl-N'jN'-dimethylurea (V) in an amount of 3 kg of active ingredient per hectare, dispersed in 500 l of water, treated. After 3 to 4 weeks it was found that the compounds I, II, III and IV compared to V have a stronger herbicidal action showed better plant tolerance on maize, barley, wheat and rye at the same time. The test results can be seen from the following table:

Crops I. II Active ingredient
III IV V Corn 10 10 0-10 10-15 20-30 barley 10
0
10 5-10
10
5-10 0-10
0
0-10 10
10
10 70
90
80 wheat rye

0 = without damage.

continuation

Unwanted plants I. II Active ingredient
III IV •. Y. Mustard
White goosefoot
Small stinging nettle ....
Two-tooth
Broomsticks
Wild oats
Annual bluegrass
Black foxtail 100
100
100
90-100
100
90-100
90-100
90-100 100
100
100
90
90
90
90
90 100
100
100
90-100
90-100
90-100
100
100 100
100
100
90-100
90
90
90-100
90-100 100
90-100
100
90
80
80
80-90
80-90

100 = total damage.

A test area filled with mustard (Sinapis arvensis), white goose foot (Chenopodium album), small nettle (Urtica urens), chickweed (Stellaria media), French herb (Galinsoga parviflora), annual Bluegrass (Poa annua) and black foxtail (Alopecurus myosuroides) was sown on the day of sowing with N - ^ - dichlorophenyl-N'-methyl-N '- (dimethylcarbamoyl) -oxyurea (I) and in comparison with N-p -chlorophenyl-N ^ N'-dimethylurea (II) each in an amount of 5 kg of active ingredient per hectare dispersed in 500 l of water, sprayed. During the emergence of the weeds and grass weeds, it was found that after 2 weeks the active ingredient I has already killed the weeds and grass weeds, while with the active ingredient II the weeds and Weeds only died completely after 4 to 5 weeks.

An agricultural area covered with field mustard (Sinapis arvensis), white goosefoot (Chenopodium album), small nettle (Urtica urens), chickweed (Stellaria media), French herb (Galinsoga parviflora), annual bluegrass (Poa annua) and field foxtail (Alopecurus) was overgrown, with a height of the weeds of 3 to 8 cm with N-3,4-Diehlophenyl-N'-methyl- W- (2,4-dichlorophenoxyacet) - oxyurea (II) in an amount of 5 kg of active ingredient per hectare dispersed in 5001 water, treated. After a few days it could be observed that the compound I showed a stronger herbicidal action on the weeds and grass weeds than the compound II. After 3 weeks almost all of the plants had died off completely. so

The plants Zea mays, Hordeum vulgare, Triticum vulgar, Oryza sativa, Echinochloa crus-galli, Setaria viridis, Panicum capillare, Poa annua, Alopecurus myosuroides, Matricaria chamomilla, Stellaria media, Polygonum persicaria, Chrysanthemum segetum, Solanum nigrum, Ipomoea purpurea and Lamium amplexicaule were at a height of 3 to 18 cm with 2 kg / ha active ingredient N-p-fluorophenyl-N ' - methyl - N '- (dimethylcarbamoyl) - oxyurea I, dispersed in 5001 water per hectare, treated.

After 3 to 4 weeks it was found that the undesirable plants were strong and the useful plants were only slightly damaged.

Claims (2)

Patent claims: 1. N-phenyl-N'-hydroxyurea esters of the general formula X, - CO- N < ^X OCO -R in which X ₍ " _{= 1} ) represents a fluorine, chlorine or bromine atom, a trifluoromethyl or nitro group in the 3- or 4-position or X _{(n = 2} ) chlorine atoms in the 3,4-position and R represents a dimethylamino- , i - propyl, isopropenyl, 2 - chloro-butyl- (2) -, bromo-t-butyl, 3-n-heptyl, cyclopropyl or 2,4-dichlorophenoxymethyl radicals. 2. Use of N-phenyl-N'-hydroxyurea esters according to claim 1 as herbicides.