JPH0552300B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a phenoxybenzylurea derivative represented by the following general formula and a herbicide containing the compound as an active ingredient. [In the formula, R ₁ and R ₂ are hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, alkenyloxy groups, alkynyloxy groups, aralkyloxy groups, cycloalkyl groups, aralkyl groups, or phenyl groups (halogen atoms) , or may be substituted with a methyl group), or R ₁ and R ₂ may form a carbon ring. X ₁ , X ₂ , and X ₃ represent a hydrogen atom, a chlorine atom, or a trifluoromethyl group. (Effect of the invention) The phenoxybenzylurea derivative represented by the above general formula of the present invention is a new compound that has not been described in literature, patents, etc., and as a result of synthesizing it and carrying out various research, it has been found that it is an excellent herbicide. It was recognized that it has an effect. That is, the compound of the present invention exhibits strong herbicidal activity against a wide range of weeds, and the active ingredient is administered at 0.1 to 20 kg per hectare, preferably 0.5 to 10 kg, immediately before the weeds germinate or at the early stage of their growth.
When Kg is applied, a wide range of weeds as described below can be killed within about 1 to 2 weeks. In addition, by limiting the amount of this compound applied or applying an appropriate application method, it can be applied to corn, potatoes, sugarcane, peanuts, soybeans,
Sunflower, barley, wheat, sorghum, paddy rice, cotton,
Weeds can be selectively controlled in fields where specific crops such as fruit trees are cultivated. In particular, in paddy fields, weeds, which are strong weeds, can be grown without causing chemical damage to paddy rice.
It is characterized by its ability to control firefly and water snail. (Structure of the Invention) Typical examples of the compounds of the present invention include those shown in Table 1. In addition, the compound is indicated by the symbol in the above general formula. In addition, NMR in the physical properties column represents nuclear magnetic resonance spectrum, the measurement solvent is shown in parentheses, and the unit is
It is ppm. mp represents uncorrected melting point. Also,
_nD indicates the refractive index. Others follow conventional expression methods.

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[Table] The compound of the present invention can be synthesized, for example, according to the following formula. [In the formula, R ₁ represents an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aralkyl group, or a phenyl group (which may be substituted with a halogen atom or a methyl group), and X ₁ , X ₂ , X ₃ represents a hydrogen atom, a chlorine atom, or a trifluoromethyl group. ] [In the formula, R ₁ and R ₂ are an alkyl group, an alkenyl group,
It represents a cycloalkyl group, an aralkyl group, or a phenyl group (which may be substituted with a halogen atom or a methyl group), or R ₁ and R ₂ may form a carbon ring. X ₁ , X ₂ , and X ₃ represent a hydrogen atom, a chlorine atom, or a trifluoromethyl group. ] [In the formula, R ₁ and R ₂ are hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, alkenyloxy groups, alkynyloxy groups, aralkyloxy groups, cycloalkyl groups, aralkyl groups, or phenyl groups (halogen atoms) , or may be substituted with a methyl group), or R ₁ and R ₂ may form a carbon ring. X ₁ , X ₂ , and X ₃ represent a hydrogen atom, a chlorine atom, or a trifluoromethyl group. ] [In the formula, R ₁ is an alkyl group, a cycloalkyl group,
or a phenyl group (which may be substituted with a halogen atom or a methyl group), and X ₁ , X ₂ , and X ₃ each represent a hydrogen atom, a chlorine atom, or a trifluoromethyl group. ] [In the formula, R ₁ is an alkyl group, a cycloalkyl group,
or represents a phenyl group (which may be substituted with a halogen atom or a methyl group), R is an alkyl group,
represents an alkenyl group, an alkynyl group, or an aralkyl group, hal represents a chlorine atom, a bromine atom, or an iodine atom, and X ₁ , X ₂ , and X ₃ represent a hydrogen atom, a chlorine atom, or a trifluoromethyl group] Step Regarding (1), (2), (3) or (4). The solvent may be appropriately selected from inert solvents such as benzene, toluene, chloroform, dichloromethane, dioxane, ethyl ether, tetrahydrofuran, acetone, methyl ethyl ketone, dimethyl formamide, dimethyl sulfoxide, acetonitrile, or a tertiary amine used as a base. can be used. Alternatively, the reaction may be carried out without a solvent depending on the case. Suitable bases include tertiary amines such as pyridine, triethylamine, and N,N-dimethylaniline, alkalis such as potassium carbonate, sodium carbonate, sodium hydroxide, and potassium hydroxide, and sodium hydride. The reaction temperature is generally from 0°C to the reflux temperature of the solvent. Regarding process (5). The solvent can be appropriately selected from lower alcohols such as methanol, ethanol, n-propanol, dimethylformamide, benzene, toluene, and the like.
Suitable bases include sodium methoxide, sodium ethoxide, potassium t-butoxide, sodium hydroxide, potassium hydroxide, and sodium hydride. The reaction temperature is generally 0
℃ to the reflux temperature of the solvent is suitable. Typical synthesis examples are shown below and explained in more detail. Synthesis Example 1 3-(α,α-dimethyl-m-phenoxybenzyl)-1-methyl-1-phenylurea (Compound No. 6) 2.5 g of α,α-dimethyl m-phenoxybenzyl isocyanate Add 1.1 g of N-methylaniline to the benzene solution and heat under reflux for 3 hours.
After cooling, wash in the following order: 2N aqueous sodium hydroxide solution, 2N hydrochloric acid, and water. After drying with magnesium sulfate, the solvent is distilled off under reduced pressure to obtain crystals. When this crystal is recrystallized from benzene-n-hexane, 2.9 g of the target compound (No. 6) is obtained. Synthesis Example 2 1-(p-tolyl)-3-(α,α-dimethyl-
m-Phenoxybenzyl)urea (Compound No. 5) To a solution of 1.3 g of p-tolylisocyanate in 50 ml of cyclohexane, 2.3 g of α,α-dimethyl-m-phenoxybenzylamine was added and left overnight at room temperature. do. The obtained crystals are thoroughly washed in the order of 2N potassium hydroxide aqueous solution, 2N hydrochloric acid, water, and n-hexane to obtain 3.3 g of the target compound (No. 5). Synthesis example 3 1-n-butyl-3-(α,α-dimethyl-m
-Phenoxybenzyl)urea (Compound No. 9) To a chloroform solution of 2.5 g of α,α-dimethyl-m-phenoxybenzyl isocyanate was added 1.0 g of n-butylamine, and the mixture was heated under reflux for 2 hours. Next, the solvent is distilled off under reduced pressure to obtain crystals. By thoroughly washing the crystals with n-hexane, 2.9 g of the target compound (No. 9) was obtained. Synthesis example 4 1-n-butyl-3-(α,α-dimethyl-p
-Phenoxybenzyl)-1-methylurea (Compound No. 19) α,α-Dimethyl-p-
Add 2.5g of phenoxybenzylisocyanate,
Heat under reflux for 1 hour. After cooling, 2N-hydrochloric acid, 2N
- After washing with an aqueous sodium hydroxide solution and then water, and drying with magnesium sulfate, treatment with florisil column chromatography (dichloromethane solvent) yields 2.9 g of the target compound (No. 19) as a transparent syrup-like substance. . Synthesis Example 5 3-[m-(2,4-dichlorophenoxy)-α,
α-Dimethylbenzyl]-1,1-dimethylurea (Compound No. 47) m-(2,4-dichlorophenoxy)-α,α-
Dissolve 3.0 g of dimethylbenzylamine and 1.1 g of triethylamine in 25 ml of toluene, and dissolve N,N-dimethylcarbamoyl chloride while stirring at room temperature.
A solution of 1.1 g in 5 ml of toluene is added dropwise over 15 minutes.
Next, the mixture was stirred at room temperature for 30 minutes, then heated to 60°C and stirred for 6 hours. After cooling, water was added to separate the organic layer, and the resulting organic layer was mixed with 2N-hydrochloric acid and 2N
- Wash with sodium hydroxide and then with water and dry with magnesium sulfate. The solvent is removed under reduced pressure to obtain crude crystals. This crude crystal was mixed with benzene.
Recrystallization from a mixed solvent of n-hexane yields 2.6 g of the target compound (No. 47) as white crystals. Synthesis Example 6 1-allyloxy-3-(α,α-dimethyl-
m-Phenoxybenzyl)-1-phenylurea (Compound No. 45) A solution of 20 ml of ethyl ether containing 3.4 g of N-phenylhydroxylamine was placed in a 100 ml three-necked flask, and while stirring well at room temperature, α、α
A solution of 7.6 g of dimethyl-m-phenoxybenzyl isocyanate in 30 ml of benzene is added dropwise.
Next, the reaction is carried out at room temperature for 1 hour and heated at 35°C for 3 hours. After the reaction, the reaction solution was washed twice with water, dried over magnesium sulfate, and the solvent was distilled off.
-(α,α-dimethyl-m-phenoxybenzyl)
10.5 g of -1-hydroxy-1-phenylurea are obtained as crude product. 3.6 g of this 3-(α,α-dimethyl-m-phenoxybenzyl)-1-hydroxy-1-phenylurea was added to a solution of 20 ml of methanol containing 0.55 g of sodium methylate.
After making a homogeneous solution, 1.3 g of allyl bromide is added at room temperature. Stirring is carried out at room temperature for 2 hours, followed by heating under reflux for 30 minutes. Next, the solvent is distilled off under reduced pressure, dichloromethane and water are added to the resulting residue, and the organic layer is separated. The organic layer was washed with 5% hydrochloric acid, 10% aqueous sodium carbonate solution, and water in this order. After drying with sodium sulfate, the solvent is distilled off. The obtained syrup-like substance was treated with silica gel column chromatography (toluene-n-hexane mixed solvent system), and the target compound (No. 45) was obtained as white crystals.
3.2g obtained. The active compounds according to the invention can be formulated into dosage forms such as emulsions, wettable powders, pastes, floatables, powders, and granules by applying conventional formulation methods. Furthermore, the compounds of the present invention can be mixed with other herbicides. Furthermore, in order to expand the range of action, it can be used in combination with agricultural chemicals other than herbicides, such as insecticides and fungicides. (Example) Next, examples of typical dosage forms will be given. "Parts" in the description indicate parts by weight. Example 1 Wettable powder Compounds 50 shown in Table 1 as active ingredients
10 parts diatomaceous earth, 35 parts clay, 3 parts sodium polyoxyethylene alkyl allyl ether sulfonate, and 2 parts sodium alkylnaphthalene sulfonate.
A wettable powder containing 50% of the active ingredient compound is obtained by mixing and pulverizing the two parts. When using, dilute with water to the specified concentration and spray. Example 2 Granules 10 parts of the compound in Table 1, 20 parts of bentonite, clay
Mix 68 parts of sodium dodecylbenzenesulfonate and 2 parts of sodium dodecylbenzenesulfonate, add about 20 parts of water, knead with a mixer, granulate through a granulator, and then dry and granulate to contain 10% of the active ingredient. Obtain granules. The novel thiophene derivative of the general formula has excellent herbicidal activity and is therefore suitable for controlling weeds growing in rice fields, fields, orchards, non-agricultural lands, etc. When this active compound is applied to the soil surface or mixed into the soil, it can significantly inhibit the growth of weeds and cause them to die. Weeds can also be controlled by spraying this agent on the stems and leaves of growing weeds. If the dosage of this compound is controlled and the application rate is selected to be 0.5 to 20 kg per hectare, it can be used in cultivated fields such as paddy rice, corn, wheat, barley, sugar cane, soybean, peanuts, sunflowers, potatoes, cotton, or fruit trees. It can be used as a targeted herbicide. It can also be applied as a non-selective herbicide by increasing the application rate. The compounds of the present invention can be used, for example, to control the following weeds: That is, dicotyledonous plants such as Stellaria media, Chenopodium album, Sagina
japonica), Chonopodium
ficifolium), Polysonum
nodosum), Purslane (Portulaca oleracea),
Capsella bursa-pastoris, Lepidium virginicum, Porippa indica, Cardamine flexuosa, Abutilon
avicennae), American golden deer (Sida
spinosa), Ammannia spinosa
multiflora), Ipomoea
Purpurea), Senecio vulgaris, Sonchus asper, Bidens frondosa, Ambrosia
artemisiifolia), Aster
subulatus), Hotokenoza (Laium
amplexicaule), Oxalis
corniculata), Amaranthus
retroflexus), Vicia sativa,
Galium aparine, Solanum nigrum, Datura stramonium, Monochoria
Poa annua, Alopeculus aequalis, Digitaria
adscendens), Eleusine indica, Setaria viridis, Echinochloa crusgalli, Agropyron kamoji, Lolium
perenne), Bromus unioloides, Avena fatua, Polypogon Higegaweri, Panicum dichotomiflorum, Cyperaceae weeds such as Cyperus
microiria), firefly (Scirupus iuncoides),
Cyperus serotinus, Cyperus difformis, Cyperus difformis
rotundus), Cyperus lria, Eleocharis acicularis, etc. The compound of the present invention has a herbicidal effect on a wide range of weeds as described above, and when sprayed on the field soil surface, the foliage surface of plants, or in waterlogged areas, immediately before or after the weeds germinate. , or when mixed into the soil, an excellent weed control effect can be obtained. In particular, flooded soil treatment has an extremely high control effect on paddy field weeds. In order to demonstrate the herbicidal effect of the pesticide according to the present invention,
A more detailed explanation will be provided by giving some representative test examples. Test example 1 Pre-emergence soil treatment
Weeding effect on plants when using volcanic ash soil in pots with an area of ¹⁰⁰ cm2.
japonicus), Amaranthus
retroflexus), corn (Zea mays), wheat (Triticum aestivum), corn (Phaseolus)
radiatus), Chrysanthemum
sow the seeds of coronarium, cover with about 5 mm of soil,
Immediately thereafter, compounds such as those listed in Table 1 were added to Example 1.
Prepare a hydrating powder according to the following, dilute it with water,
A dose equivalent to 8 kg of active ingredient per hectare was applied to the soil surface of each pot. Two weeks after treatment, the herbicidal effect on plants was investigated. The herbicidal effect was visually observed and expressed in Table 2 using an 11-level index from 0: no effect to 10: complete death. Test Example 2 Herbicidal effect on plants when subjected to foliar spray treatment A pot with an area of 100 cm ² was filled with volcanic ash soil, and a pot of volcanic ash soil was applied to the plants.
japonicus), Amaranthus
retroflexus), corn (Zea mays), wheat (Triticum aestivum), Japanese lily (Phaseolus radiatus), and Chrysanthemum coronarium.
Cover with soil to a depth of about 1cm and place it in the greenhouse until there are 1 to 2 weeds.
When the leaves formed, a hydrating powder of the compound of the present invention was diluted in an amount equivalent to 8 kg/ha with water equivalent to 1000/ha and sprayed using a sprayer. Ten days after the chemical spraying, the results were investigated using the same criteria as in Test Example 1, and the results were expressed using an 11-level index. The test results are shown in Table 3. Test Example 3 Herbicidal effect on paddy field weeds and chemical damage to paddy rice A pot with an area of 120 cm ² was filled with paddy soil, and the pots were filled with rice field soil (Echinochoa crus-galli), bulrush (Scirpus juncoides), Ammannia multiflora, Monochoria vaginalis (Monochoria vaginalis), Approximately 2 seeds on the surface
cm of soil, and the pine beetle (Eleocharis
acicularis) and paddy rice at the two-leaf stage were transplanted to two locations each, and the water depth was maintained at approximately 3 cm. Three days later, a hydrating powder containing the compound of the present invention prepared according to Example 1 was administered into water at a dose equivalent to 8 kg per hectare. Three weeks after chemical treatment, the herbicidal effect and chemical damage to paddy rice were investigated. Herbicidal effects and chemical damage to crops were investigated using the same criteria as in Test Example 1, and expressed using an 11-level index. The test results are shown in Table 4. From Table 4, it can be seen that the compounds of the present invention are effective in killing weeds, which are important weeds in rice fields, such as grasshopper, bulrush, Japanese grasshopper, Japanese grasshopper, and Japanese grasshopper. Test Example 4 Herbicidal effect at low doses on paddy field weeds and chemical damage to paddy rice Echinochoa crus-galli, Scirpus iuncoides, Cyperus
The control effect against P. serotinus and the chemical damage to paddy rice were tested in the same manner as in Test Example 3. The test results are shown in Table 5.

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Claims (1)

[Claims] 1. General formula [In the formula, R ₁ and R ₂ are hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, alkenyloxy groups, alkynyloxy groups, aralkyloxy groups, cycloalkyl groups, aralkyl groups, or phenyl groups (halogen atoms) , or may be substituted with a methyl group), or R ₁ and R ₂ may form a carbon ring. X ₁ , X ₂ , and X ₃ represent a hydrogen atom, a chlorine atom, or a trifluoromethyl group. ] A phenoxybenzylurea derivative represented by. 2 General formula [In the formula, R ₁ and R ₂ are hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, alkoxy groups, alkenyloxy groups, alkynyloxy groups, aralkyloxy groups, cycloalkyl groups, aralkyl groups, or phenyl groups (halogen atoms) , or may be substituted with a methyl group), or R ₁ and R ₂ may form a carbon ring. X ₁ , X ₂ , and X ₃ represent a hydrogen atom, a chlorine atom, or a trifluoromethyl group. ] A herbicide containing a phenoxybenzylurea derivative as an active ingredient.