JPH0526779B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the general formula (In the formula, X represents a lower alkoxy group, an allyloxy group, or a dimethylamino group. Y is an oxygen atom or an imino group, n is O or I, R are a lower alkyl group, a halogenated lower alkyl group, a lower alkenyl group, The present invention relates to a pyrazole derivative represented by a benzyl group, a phenyl group, a lower alkyl group, a lower alkoxy group, or a phenyl group substituted with a halogen atom), and a herbicide containing the compound as an active ingredient. The compound of the present invention is a new compound that has not been described in literature, patents, etc., and is characterized by having a tertiary butyl group at the 3-position of the pyrazole ring, as shown in the general formula, and has a very significant herbicidal activity. I have it too. The compound of the general formula shows strong herbicidal activity against a wide range of weeds, and if this active ingredient is applied at 0.5 to 10 kg per hectare just before the weeds germinate or at the early stage of their growth, it will take about 2 to 3 weeks. Over time, it can kill a wide range of weeds as described below. In addition, by limiting the amount of this compound applied or applying an appropriate application method, it is possible to cultivate specific crops such as corn, potatoes, sugarcane, peanuts, soybeans, sunflowers, barley, wheat, sorghum, cotton, and fruit trees. Weeds can be selectively controlled in the field. Typical examples of the compounds of the present invention include those shown in Table 1. The compounds in the table are numbered, and the compound numbers are also indicated in the following explanation. The melting point values in the table are uncorrected, and the NMR values were measured at 60 MHz using tetramethylsilane in deuterium chloroform as a reference material, and the symbols s, d, t, q, and m indicate peak patterns. 1, 2, 3, 4, multiplet, ar indicates a peak due to aromatic H, or br indicates a wide peak pattern, and J indicates a spin coupling constant.

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[Table] Among the compounds of the present invention, Y is an oxygen atom (n=1)
Alternatively, those represented by n=0 can be produced, for example, according to the following reaction formula. (In the formula, the symbol X is as described above, and Z represents a chlorine atom or a bromine atom.) This reaction usually involves benzene, toluene, xylene, carbon tetrachloride, chloroform, methylene chloride,
It is carried out in an organic solvent such as dioxane, acetonitrile, acetone, etc. at a temperature of about 0 to 120°C. A base such as pyridine, triethylamine, sodium carbonate, potassium carbonate, etc. may be present in some cases. Further, when n=0, RCOZ is used, but the reaction can also be carried out in the same manner as above using (RCO) ₂ O instead. If X and YnR are the same, they can also be produced directly from the raw material amine according to the following reaction formula. The reaction conditions in this case are the same as above. On the other hand, when Y is an imino group (n=1), it can be produced by the following reaction formula. (Symbols in the formula are as above) The reaction conditions in this case are the same as above. The compounds produced by the above reaction are generally sparingly soluble in water, but are highly soluble in most organic solvents such as alcohols, acetone, benzene, toluene, carbon tetrachloride, and chloroform, and are also compatible with hydrocarbon solvents such as hexane. It is melting. Next, synthesis examples will be shown for reference, and the method for producing the active compound of the present invention will be specifically described. Example 1 1.5 g of methyl N-(3-tertiarybutyl-5-pyrazolyl)carbamate in 30 ml of carbon tetrachloride
Add 0.9 g of ethyl chloroformate to this and react under heating and reflux for 5 hours. After cooling, the reaction solution was washed with a 5% aqueous sodium carbonate solution and water, and the organic layer was dried over anhydrous sodium sulfate, then concentrated and crystallized. This was washed with hexane and passed through the mouth to obtain 1.6 g of methyl N-(3-tertiarybutyl-1-ethoxycarbonyl-5-pyrazolyl)carbamate (Compound 14). Identification of the compound was performed by infrared, NMR and X-ray analysis. Example 2 6 g of methyl N-(3-tertiarybutyl-5-pyrazolyl) carbamate was placed in 50 ml of benzene, 3.5 g of methyl chloroformate was added, and the mixture was allowed to react under heating under reflux for 5 hours. After cooling, the same treatment as in Example 1 was carried out to obtain 6.5 g of methyl N-(3-tert-butyl-1
-methoxycarbonyl-5-pyrazolyl)carbamate (compound 13) was obtained. Example 3 1.5 g of methyl N-(3-tertiarybutyl-5-pyrazolyl) carbamate was placed in 30 ml of benzene, 1 g of triethylamine and 0.7 g of acetyl chloride were added thereto, and the mixture was heated under reflux for 3 hours. After cooling, the same treatment as in Example 1 was carried out to obtain 1.4 g of methyl N-(1-acetyl-3-tertiarybutyl-5-pyrazolyl) carbamate (Compound 1). Example 4 1.5 g of methyl N-(3-tertiarybutyl-5-pyrazolyl)carbamate in 30 ml of dioxane
Take and add 1.0g of phenyl isocyanate.
Heat to 100°C and react for 2 hours. After cooling, dioxane was distilled off, crystallized, washed with hexane, and passed through the mouth to obtain 1.6 g of methyl N-(3-tertiarybutyl-1-phenylcarbamoyl-5-pyrazolyl)carbamate (compound 19). Obtained. Example 5 2.1 ethyl N-(3-tertiarybutyl-5-pyrazolyl)carbamate in 30 ml of methylene chloride
g was added, 1.3 g of chloroacetyl chloride was added thereto, and the reaction was carried out under heating and reflux for 3 hours. After cooling, the same treatment as in Example 1 was carried out to obtain ethyl N-(3-tertiarybutyl-1-chloroacetyl-5 -pyrazolyl) carbamate (compound 22) was obtained. Example 6 N,N-dimethyl-
N'-(3-tertiarybutyl-5-pyrazolyl)
2.1 g of urea was taken, 0.8 g of acetyl chloride was added, the reaction was heated under reflux for 1 hour, the mixture was allowed to cool, and the same treatment as in Example 1 was carried out to obtain N,N-dimethyl-N'-(1-acetyl 3-tertiary chloride). 2.0 g of butyl-5-pyrazolyl)urea (compound 29) was obtained. Although some production examples have been shown above, other compounds can also be synthesized by similar methods. 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, nematicides, and fungicides. 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 of diatomaceous earth, 35 parts of clay, 3 parts of sodium polyoxyethylene alkyl acrylic ether sulfonate, and 2 parts of sodium alkylnaphthalene sulfonate are mixed and ground to obtain a wettable powder containing 50% of the active ingredient compound. When using, dilute with water to the specified concentration and spray. Example 2 Granules 5 parts of the compound in Table 1, 20 parts of pentonite, clay
Mix 73 parts 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 5% of effective ingredients. Obtain granules. Example 3 Emulsion Compound 50 shown in Table 1 as active ingredient
45 parts of xylene and 5 parts of polyoxyethylene alkyl allyl ether are mixed to form a homogeneous solution to obtain an emulsion containing 50% of the active ingredient. When using, dilute with water to the specified concentration and spray. The novel pyrazole derivative of the general formula has excellent herbicidal activity and is therefore suitable for controlling weeds growing in 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 5 kg per hectare, corn,
It can be used as a selective herbicide in cultivated fields of wheat, barley, sugarcane, soybean, peanuts, sunflowers, potatoes, cotton, or fruit trees. 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, and Sagima
japonica), Chonopodium
ficifolium), Polygomin
nodosum), Purslane (Portulaca oleracea),
Capsella bursapastoris, Lep dium virginicum, Porippa indica, Cardamine
Hexuosa), Abutilon avicennae, Sida spinosa, Ipomoes purpurea, Senecio vulgaris, So-nchus
asper), Bidens
frondosa), ragweed (A mbrosia)
artemisiaefolia) Aster
subulatus), Hotokenoza (Lamium am
plexicavle), oxalis (Oxalis cornicolate),
Amaranthus retroflexus, Vicia sativa, Galium
spurium), Solanum nigrum,
Datura stramonium, etc.
Poaceae, such as Poa
annua), AlopecuIus
aequlis), Digitaria adsendens, Eleusine indica, Setaria viridis, Echinochloa crus
-galli), Agropyron
tsukushiensis), Lolium perenne (Lolium perenne),
Bromus catharticos, oat (Avena tatua), polypogon
Higegaweri), Panicum
dichotomiflorom), Cyperaceae weeds such as Cyperus microiria, Cyperus lria, Carex
rugata) etc. The compounds of the present invention have excellent herbicidal efficacy against a wide range of weeds as described above, and are particularly effective when applied to the surface of fields or the foliage of plants just before or after weeds germinate. High pest control effect can be obtained. Also, when the compound of the present invention is mixed into soil, an extremely excellent weed control effect can be obtained. In order to demonstrate the herbicidal effect of the herbicide 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
Herbicidal effect on plants when volcanic ash soil is filled in pots with an area of 100 ^cm2 , and volcanic ash soil is poured into pots with an area of 100 cm2, and the soil is filled with volcanic ash soil. ), wheat (Triticum aestivum),
Sow the seeds of Phaseolus radiatus,
Immediately after covering the soil with a thickness of about 5 mm, prepare the compounds listed in Table 1 into a wettable powder according to Example 1, dilute this with water, and obtain the amount of active ingredients per hectare.
A dose equivalent to 10 kg was administered to the soil surface of each pot. Two weeks after treatment, the herbicidal effect on plants was investigated. The weeding effect was visually observed: 0: No effect ~
5: Displayed in Table 2 as an index of 6 levels of complete death. Test Example 2 Herbicidal effect on plants when subjected to foliar spray treatment A pot with a surface area of 100 cm ² was filled with volcanic ash soil, and a pot with a surface area of 100 cm 2 was filled with volcanic ash soil, and the following samples were applied: Sow the seeds of Amaranthus retroflexus, Zea mays, Triticum aestivum, and Phaseolus radiatus, cover with about 1 cm of soil, and leave at room temperature. When the weeds have one or two leaves, A hydrating powder of the compound of the present invention was diluted in an amount equivalent to 10 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 a 6-level index. The test results are shown in Table 3. Test Example 3 Herbicidal effect on paddy weeds and phytotoxicity test on paddy rice A pot with a surface area of 120 cm ² was filled with paddy soil.
Seeds of Echinochioa crus-gaili and Monochoria vaginalis were mixed into the soil approximately 2 cm above the surface, and
acicularis) and two-leaf stage paddy rice fungi.
Transplant to a new location and keep the water depth at about 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 dosage equivalent to 10 kg per hectare. Three weeks after chemical treatment, the herbicidal effect and chemical damage to paddy rice were investigated. The herbicidal effect and the chemical damage to crops were investigated using the same criteria as in Test Example 1, and expressed using a 6-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 paddy fields, such as weeds, grasshoppers, and grasshoppers. However, this group of compounds also affects paddy rice.

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[Table] From the above results, it is clear that the compounds of the present invention exhibit strong herbicidal activity against a wide range of weeds, and can be applied as herbicides for various crops.

Claims (1)

[Claims] 1. General formula (In the formula, X represents a lower alkoxy group, an allyloxy group, or a dimethylamino group. Y is an oxygen atom or an imino group, n is 0 or 1, and R is a lower alkyl group, a halogenated lower alkyl group, a lower alkenyl group, or a benzyl group. phenyl group, lower alkyl group, lower alkoxy group, or phenyl group substituted with a halogen atom). 2 General formula (In the formula, X represents a lower alkoxy group, an allyloxy group, or a dimethylamino group. Y is an oxygen atom or an imino group, n is 0 or 1, and R is a lower alkyl group, a halogenated lower alkyl group, a lower alkenyl group, or a benzyl group. A herbicide containing, as an active ingredient, a pyrazole derivative represented by a phenyl group, a phenyl group, a lower alkyl group, a lower alkoxy group, or a phenyl group substituted with a halogen atom.