JPH0371424B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is based on the general formula (In the formula, R is a lower alkyl group, and X is a hydrogen atom, a chlorine atom, or a bromine atom.) 5-tertiarybutyl-3-birazolylcarbamic acid is a new compound not described in literature, etc. The present invention relates to an ester derivative, a method for producing the same, and a herbicide containing the compound as an active ingredient. Note that the compound of the general formula has tautomers as shown in the following formula, but in the following explanation, both are represented by the formula. The compound of the present invention is characterized by having a tertiarybutyl group at the 5-position of the pyrazole ring, as shown in the general formula, and has a very significant herbicidal activity. Further, it is preferable that the 4th position of the pyrazole ring is unsubstituted or a halogen atom such as a chlorine atom or a bromine atom is introduced. 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 in 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 explanations. The melting point values in the table are uncorrected, and the NMR values were measured at 60 MHz using tetramethylsilane in deuterochloroform as a reference material, and the symbols s, d, t, q, and m have peak patterns, respectively. 1, 2, 3, 4, multiplet, or br indicates a wide peak pattern, and J represents a spin coupling constant. However, when measuring Compounds 1 and 7, some heavy dimethyl sulfoxide was added.

【table】

[Table] The compound of the present invention can be produced, for example, according to the following reaction formula (wherein R is as described above). If this reaction is carried out in the presence of a dehydrochlorination agent such as triethylamine in the solvent as usual, the nuclei will be removed.
The byproduct of the reaction between NH and chloroformic acid ester is
occurs more than a. Therefore, in a solvent such as benzene, toluene, xylene, carbon tetrachloride, chloroform, dioxane, etc., without using a dehydrochlorination agent,
It is best to do this at a temperature of around 150℃. It is easy to chlorinate or bromine the 4-position of the pyrazole ring, and chloroform, dichloromethane,
A 5-tert-butyl-3-pyrazolecarbamate derivative which is unsubstituted at the 4-position is chlorinated or Produced by bromination. The compound produced by the above reaction is generally sparingly soluble in water, but relatively easily soluble in ordinary organic solvents, and particularly well soluble in alcohols, acetone, and the like. However, it is difficult to dissolve in petroleum solvents such as hexane and pentane. Incidentally, the raw material compound used in the above reaction can be produced from cyanopinacholine and hydrazine, for example, according to the following reaction formula. 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 Production of 5-amino-3-tertiarybutylpyrazole () 125g (1 mol) of cyanopinacholine was added to ethanol.
Dissolve to 200 ml, add 55 g of hydrazine hydrate, and heat under reflux for 2 hours. After the reaction, ethanol is distilled off, alkaline water is added to the residue, extracted with 500 ml of benzene, dried over anhydrous sodium sulfate, and benzene is distilled off. The residue solidifies upon notification, and 3-amino-5
- 131 g of tertiary butylpyrazole () are obtained. Example 2 Methyl-N-(5-tertiarybutyl-
Production of 3-pyrazolyl)carbamate (1) 10 g obtained in Example 1 was dissolved in 100 ml of carbon tetrachloride, 6.8 g of methyl chloroformate was added, and the mixture was reacted under heating under reflux for 5 hours. After cooling, an aqueous potassium carbonate solution is added to form crystals. This was filtered and washed with carbon tetrachloride and water to obtain 3.8 g of Compound 1. After recrystallization with a mixed solvent of carbon tetrachloride and chloroform, the melting point was 177°C. Example 3 Ethyl-N-(5-tertiarybutyl-
Production of 3-pyrazolyl)carbamate (2) 2.8 g of pyrazoleamine was dissolved in 30 ml of dioxane, 2.2 g of ethyl chloroformate was added, and the mixture was reacted under heating under reflux for 5 hours. After the reaction, the solvent is distilled off, and hexane and an aqueous potassium carbonate solution are added to crystallize. After filtration and washing with water and hexane, 1.1 g of compound 2 was obtained. Example 4 Preparation of Compounds 3, 4, and 5 A reaction was carried out in the same manner as in Example 3 using isopropyl chloroformate, n-butyl chloroformate, and isobutyl chloroformate instead of ethyl chloroformate.
4 and 5 can be manufactured. Example 5 Methyl-N-(5-tertiarybutyl-
4-chloro-3-pyrazolyl) carbamate (6)
Preparation of 2 g of Compound 1 is suspended in 30 ml of carbon tetrachloride, and 1.4 g of sulfuryl chloride is added dropwise at 20-25°C with stirring.
After reacting for an additional 2 hours, an aqueous sodium carbonate solution is added. The organic layer was taken, and after distilling off the solvent, hexane was added to crystallize it to obtain 1.0 g of Compound 6. Example 6 Methyl-N-(5-tertiarybutyl-
4-Bromo-3-pyrazolyl)carbamate (7)
Preparation: Dissolve 2 g of compound 1 in 30 ml of acetic acid and add 1.6 g of bromine. After reacting for 2 hours at room temperature, the reaction mixture was poured into ice water and crystallized to obtain 1.5 g of Compound 7. The active compounds according to the invention can be formulated into dosage forms such as emulsions, wettable powders, pastes, flowable powders, granules, etc. 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. Next, examples of typical dosage forms will be given. "Parts" in the description indicate parts by weight. Example 1. Hydrating agent Compound 50 shown in Table 1 as an active ingredient
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 bentonite, clay
Mix 73 parts and 2 parts of sodium dodecylbenzenesulfonate, add about 20 parts of water, knead with a mixer, granulate with a granulator, and then dry and granulate to contain 5% of the active ingredient. Obtain granules. Example 3. Emulsion Compound 15 shown in Table 1 as active ingredient
parts, 40 parts of dimethylacetamide, 40 parts of xylene, and 5 parts of polyoxyethylene alkyl allyl ether.
A homogeneous solution is obtained by mixing the two parts to obtain an emulsion containing 15% of the active ingredient. When using, dilute with water to the specified concentration and spray. The novel carbamate ester 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 sprayed onto the surface of the soil or mixed into the soil, it is possible to 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, soybeans, peanuts, sunflowers, potatoes, cotton, fruit trees, etc. 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, Sagima
japonica), Chonopodium
ficifolium), Polygonum
nodosum), Purslane (Portulace oleracea),
Capsella bursapastoris, Lepidium virginicum, Porippa indica, Cardamine
Hexuosa), Abutilon avicennae, Sida spinosa, Ipomoea purpurea, Senecio vulgaris, Sonchus
asper), Bidens
frondosa), betaxa (Ambrosia
artemisiaefolia), Aster
subulatus), Hotokenoza (Lamium
amplexicavle), Oxalis
cornicolate), Amaranthus
retrotlexus), Vicia sativa (Vicia sativa)
), Gallium spurium, Solanum nigrum, Datura stramonium, etc., Poa annua, Alopeculus aequalis, Digitaria adsens, Eleusine
indica), Setaria viridis, Echinoshlor crus-galli, Agropyron tsukushiensis, 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 the 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. ), wheat (Triticum aestivum),
Sow the seeds of Phaseolus radiatus,
Immediately after covering the soil with a thickness of approximately 5 mm, prepare the compounds listed in Table 1 into a wettable powder according to Example 1, dilute this with water, and obtain the 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.

[Table] Test Example 2 Herbicidal effect on plants when subjected to foliar spray treatment Pots with a surface area of 100 cm ² were filled with volcanic ash soil. ), blueberry (Amaranthus retroflexus), corn (Zea mays), wheat (Triticum aestivum),
Sow the seeds of Phaseolus radiatus,
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 with water equivalent to 1000 kg per hectare 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 as shown in Table 3.

[Table] Test Example 3 Herbicidal effect on paddy field weeds and phytotoxicity test on paddy rice A pot with a surface area of ^120cm3 was filled with paddy soil.
Seeds of Echinochoa crus-galli and Monochoria vaginalis were mixed into a 2 cm soil pot, and the seeds of Eleocharis were mixed.
acicularis) and two-leaf stage rice weeds.
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 such as weeds, which are important weeds in paddy fields, such as Japanese grasshopper, Japanese grasshopper, and Japanese grasshopper. However, this group of compounds also affects paddy rice.

【table】

【table】

Claims (1)

[Claims] 1. General formula (In the formula, R is a lower alkyl group, X is a hydrogen atom,
5 represented by (representing a chlorine atom or a bromine atom)
-tertiarybutyl-3-pyrazolylcarbamate ester derivative. 2 3-amino-5-tertiarybutylpyrazole with the general formula ClCO ₂ R (R represents a lower alkyl group)
A general formula characterized by reacting with a compound represented by 5- represented by (wherein R is as above)
A method for producing a tertiarybutyl-3-pyrazolylcarbamate ester derivative. 3 General formula A general formula characterized by chlorinating or brominating a 5-tertiarybutyl-3-pyrazolyl carbamate ester derivative represented by (wherein R represents a lower alkyl group) (In the formula, X′ represents a chlorine atom or a bromine atom,
R is as described above). 4 General formula (In the formula, R is a lower alkyl group, X is a hydrogen atom,
5 represented by (representing a chlorine atom or a bromine atom)
- A herbicide containing a tertiarybutyl-3-pyrazolyl carbamate ester derivative as an active ingredient.