JPH0524143B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a carbamate derivative, a method for producing the same, and a herbicide containing the compound as an active ingredient. [Prior Art] A large number of herbicides for rice cultivation have already been developed, but there is still a strong demand in the market for improved performance, safety, and reduced chemical damage. In addition, labor shortages due to a decrease in the number of agricultural workers have become serious in recent years, and labor saving in the agricultural field has become a major issue. As one of the countermeasures, paddy rice cultivation using flooded direct sowing, which eliminates the need for complicated operations such as puddling, seedling raising (or seedling raising), and rice transplanting, is becoming popular in Japan as well. The biggest problem with flooded, direct-seeded rice cultivation is traditional weeding techniques. This makes it difficult to apply weed control methods that involve spraying herbicides before and after rice planting. Traditionally, weeding in paddy fields has been done either by taking advantage of differences in drug resistance due to the different growth periods of weeds and rice, and controlling weeds that have just germinated without harming the rice that has grown, or by controlling the weeds that have just germinated without harming the paddy rice that has advanced in growth. By adsorbing to the topsoil and forming a chemical treatment layer,
Weeding has been carried out using a physical selection method, which inhibits the germination or young shoots of weeds and avoids damaging the paddy rice roots located below the chemically treated layer. Therefore, it has been extremely difficult to apply these herbicides to flooded and directly sown rice. JP-A-48-49925 and JP-A-Sho. 48- as a herbicide for direct sowing cultivation of paddy rice in paddy fields.
No. 56825 proposes and discloses that specific aryl N-aryl carbamate compounds can be used. [Problems to be Solved by the Invention] Known aryl N-aryl carbamate compounds have problems in terms of drug toxicity or efficacy. In other words, it strongly inhibits the rooting of directly sown paddy rice during germination, resulting in growth problems due to insufficient nutrient absorption from the soil, or phytotoxicity such as lodging of stems and leaves due to weak root support, or It shows almost no herbicidal activity when treating flooded soil. The present inventors have developed a plant that has a sufficient herbicidal effect and can be safely used even on soft rice such as flooded direct-seeded rice.
The present invention was completed as a result of intensive research to develop a compound with a high degree of selective activity. [Means for Solving the Problems] The compound of the present invention does not show any phytotoxicity in practical use not only in transplanted paddy rice but also in flooded and directly sown paddy rice, and has excellent herbicidal effects against many paddy weeds including field weeds. It has the effect of showing. That is, the present invention provides (1) General formula () (In the formula, A represents a halogen atom or a lower alkyl group, and B represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group having 2 or more carbon atoms.) (2) General formula () (In the formula, Y represents a hydrogen atom or a halocarbonyl group, and A represents a halogen atom or a lower alkyl group.) A phenol derivative represented by the general formula () (In the formula, Z is a halocarbonyl group when Y in the formula () is a hydrogen atom, and is a hydrogen atom when Y in the formula () is a halocarbonyl group. B is a lower alkyl group having 2 or more carbon atoms, a lower General formula (), which is characterized by reacting with an aniline derivative represented by an alkenyl group or a lower alkynyl group. (In the formula, A represents a halogen atom or a lower alkyl group, and B represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group having 2 or more carbon atoms.) A method for producing a carbamate derivative represented by the following formula. (3) General formula () (In the formula, A represents a halogen atom or a lower alkyl group, and B represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group having 2 or more carbon atoms.) It provides herbicides. The compound of the present invention is a new compound that has not been described in any literature. [Function] The carbamate derivative represented by the general formula () of the present invention can be produced according to the following reaction formula. (In the formula, A represents a halogen atom or a lower alkyl group, B represents a lower alkyl group having 2 or more carbon atoms, a lower alkenyl group, or a lower alekynyl group,
Y represents a hydrogen atom or a halocarbonyl group, and Z
is a halocarbonyl group when Y is a hydrogen atom,
When Y is a halocarbonyl group, it is a hydrogen atom. ) The above reaction is carried out in the presence of a dehydrohalogenating agent,
Further, the reaction usually proceeds in the presence or absence of a reaction solvent at a reaction temperature of 0°C to 150°C, and the reaction time is about several minutes to 48 hours. Examples of dehydrohalogenation agents include alkali hydroxides such as sodium hydroxide and calcium hydroxide, alkaline earth hydroxides such as calcium hydroxide, and alkali carbonates such as sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate. , metal hydrides such as sodium hydride, and tertiary amines such as triethylamine, dimethylaniline, and pyridine. In the above reaction formula, when Z is a hydrogen atom,
The raw material aniline derivative can be used as a dehydrohalogenating agent. Reaction solvents include water, alcohols such as methanol, ethanol, and isopropanol, ketones such as acetone and methyl ethyl ketone, aromatic hydrocarbons such as benzene, toluene, and xylene, ethers such as ethyl ether, tetrahydrofuran, and dioxane, and chlorobenzene. , halogenated hydrocarbons such as chloroform, carbon tetrachloride, and dichloroethane, and polar solvents such as dimethylformamide and dimethyl sulfoxide. In addition, when the compound of the present invention is used as a herbicide, an appropriate amount of one or more compounds represented by the above general formula () is mixed with an inert carrier, and a wettable powder, which is a usual form of agricultural chemical use, is prepared. It is used in the form of emulsions, granules, powders, etc. Examples of solid carriers include talc, clay, diatomaceous earth, bentonite, kaolin, acid clay, white carbon, pumice powder, etc. Examples of liquid carriers include water, alcohol, benzene, toluene, xylene, kerosene, cyclohexane, cyclohexanone, Isophorone, butyl cellosolve, benzyl acetate, dimethylformamide, mineral oil, etc. can be used. Furthermore, surfactants, stabilizers, etc. may be added if necessary for the formulation. Furthermore, the herbicide of the present invention can be applied in combination with other agricultural chemicals used in the same field, such as insecticides, fungicides, herbicides, plant growth regulators, or fertilizers. In particular, it may be appropriate to add and mix other herbicides for the purpose of reducing the spraying effort or for the purpose of widening the range of grass species that can be effectively controlled. Examples of herbicides that can be added include triazine herbicides such as cymetrin and promethrin, carbamate herbicides such as bentiocarb and molinate, urea herbicides such as Daimeron, 2,4-D, MCP,
Phenoxy herbicides such as MCPB and naproanilide, diphenyl ether herbicides such as nitrophene, chlornitrophene, chromethoxynil, and biphenylnox, heterocyclic herbicides such as oxadiazone, pyrazolate, pyrazoxyfen, and pentazone, butachlor, and bretyl. Amide herbicides such as chlor, bromobutide, propanil,
Examples include quinone herbicides such as ACN. By skillfully combining one or more of these herbicides, it is possible to provide a mixture that is effective against many grass species. The compound of the present invention is suitable as a herbicide active ingredient, especially for paddy field flooding treatment before weed germination. The trial amount of the compound of the present invention varies depending on the application situation, application period, application method, target grass species, etc., but generally the amount of active ingredient is 50 to 1000 g/10a, preferably 100 to 500 g/10a.
A range of g/10a is suitable. The herbicidal properties of the compounds of the present invention are that they act particularly strongly during the germination of weeds, strongly inhibiting their elongation after germination, and have an extremely long residual effect within the weeds. That is, by killing weeds, stopping their growth, or significantly inhibiting and delaying their growth, weeds lose their ability to compete with crops. Herbicidal Spectrum is highly effective against the major pests in rice fields, such as the grasshopper and the Japanese cyperus, and is also highly effective against the Japanese grasshopper and the grasshopper. On the other hand, in flooded rice cultivation, the safety of directly sown rice and transplanted rice from young seedlings is extremely high;
No effect was observed even with 10a, and it has extremely excellent selective herbicidal activity. [Example] Next, the present invention will be explained in more detail with reference to Examples. Example 1 Method for producing 4-ethylphenyl N-(3-ethoxyphenyl)-N-methylcarbomate (invention compound No. 3) 2.14 g of N-(3-ethoxyphenyl)-N-methylcarbamoyl chloride, 1.22 g of 4-ethylphenol and 1.38 g of anhydrous potassium carbonate were added to 50 ml of methyl ethyl ketone, and the mixture was heated under reflux for 48 hours. After the reaction mixture was cooled to room temperature, it was poured into cold water and the product was extracted with benzene. The benzene solution was washed with a 5% aqueous sodium hydroxide solution, water, and a saturated aqueous sodium chloride solution in this order, dried over anhydrous magnesium sulfate, and then benzene was distilled off under reduced pressure. The residue was purified by calchromatography (silica gel, developed with benzene) to obtain 2.27 g (yield 76%) of 4-ethylphenyl N-(3-ethoxyphenyl)-N-methylcarbamate. (Oil) Example 2 Method for producing 4-tert-butylphenyl N-(3-isopropoxyphenyl)-N-methylcarbamate (Compound No. 9 of the present invention) 3-isopropoxy-N-methylaniline 1.65
g and 1.38 g of anhydrous potassium carbonate in 20 ml of acetone.
2.13 g of 4-tert-butylphenyl chloroformate was added to 20 g of acetone while stirring under ice-cooling.
ml and added. After that, the mixture was stirred at room temperature for 30 minutes, and then heated under reflux for 2 hours. After the reaction mixture was cooled to room temperature, it was poured into cold water and the product was extracted with benzene. The benzene solution was washed with dilute hydrochloric acid, water, and a saturated aqueous sodium chloride solution in this order, dried over anhydrous magnesium sulfate, and then benzene was distilled off under reduced pressure. The residue was purified by column chromatography (silica gel, developed with benzene) to give 4-tert-butylphenyl N-(3-isopropoxyphenyl).
2.46 g (yield 72%) of -N-methyl carbamate was obtained. A part of this product was recrystallized from ethanol to obtain colorless crystals with a melting point of 69-70°C. Next, representative examples of the compounds of the present invention represented by the general formula () and their physical properties are shown in Table 1 below.

【table】

【table】

[Table] Next, examples of specific formulations using the compounds of the present invention will be described. In the examples, "parts" are parts by weight. Example 3 (Wettable powder) Compound No. 1 of the present invention, 10 parts was prepared as a carrier material.
87.3 parts of Clyte [trade name, manufactured by Kokofeng Kogyo Co., Ltd.], 1.35 parts of Neopellex [trade name, manufactured by Kao Atlas Co., Ltd.] as a surfactant, and 1.35 parts of Solpol 800A [trade name, manufactured by Toho Chemical Industry Co., Ltd.] The mixture was mixed and ground to obtain a 10% hydrating powder. Example 4 (Emulsion) 25 parts of Compound No. 7 of the present invention, 65 parts of benzene, and 10 parts of Solpol 800A as a surfactant were mixed and dissolved to obtain a 25% emulsion. Example 5 (Granules) Compound No. 10 of the present invention, 10 parts, bentonite 50 parts,
After mixing and pulverizing 35 parts of Kunilite [trade name, manufactured by Kokofeng Kogyo Co., Ltd.] and 5 parts of Solhole 800A as a surfactant, 10 parts of water was added and stirred uniformly.
After extrusion through a 0.7 mm sieve hole and drying, the mixture was cut into 1 to 2 mm lengths to obtain 10% granules. Next, the herbicidal effects of the compounds of the present invention will be explained using Examples and Comparative Examples. Example 6 Paddy soil made by adding water to a paddy field was poured into a directly connected 9 cm porcelain pot, various weed seeds were sown on the soil surface layer, and germinated paddy rice seeds (variety: Nipponbare, hereinafter the same) were placed on the soil surface for 50 minutes. After placing the grains, two paddy rice seedlings at the two-leaf stage were planted at a depth of 1 cm. The next day, the pots were flooded with water to a depth of 2 cm, and predetermined doses of hydrating powders of the compounds of the present invention and comparative compounds prepared according to Example 3 were diluted in 10 ml of water per pot and dropped onto the water surface. Thereafter, it was left to stand at room temperature and watered at appropriate times. Three weeks after the chemical solution treatment, the herbicidal effect and the effect on paddy rice were investigated. The herbicidal effect and phytotoxicity were determined according to the following criteria, and the results are shown in Table 2. Weeding effect judgment criteria Display of chemical damage judgment criteria Herbicidal effect display Chemical damage 5: 100% control -: No harm 4: 80% control ±: Minor damage 3: 60% control +: Small damage 2: 40% control: Medium damage 1: 20% control: Severe damage 0: 0% control 〓: Severe damage to withering

【table】

【table】

[Table] Example 7 Paddy soil that had been plowed with water was put into a porcelain pot with a diameter of 9 cm, and two paddy rice seedlings at the two-leaf stage (variety: Nipponbare, hereinafter the same) were placed at a depth of 1 cm. In addition, two paddy rice seedlings at the two-leaf stage were placed in a row so that the roots were about 1/2 buried in the soil surface layer. Subsequently, five germinated rice seeds were placed on the soil surface. The next day, the pots were flooded with water to a depth of 2 cm, and predetermined doses of wettable powders of the present invention and comparative compounds prepared according to Example 3 above were diluted in 10 ml of water per pot and dropped onto the water surface. Then leave it in the greenhouse,
Water was sprinkled in a timely manner. Three weeks after the chemical solution treatment, the effects on paddy rice were evaluated in the same manner as in Example 6, and harmful symptoms were investigated. The results are shown in Table 3.

【table】

【table】

〔Effect of the invention〕

As is clear from Tables 2 and 3, the compound of the present invention shows no phytotoxicity at all when treated at 1000 g/10a, not only to paddy rice transplanted to young seedlings, but also to paddy rice directly sown under water at the time of germination. In addition, weeds such as weeds can be effectively controlled. In this way, the compound of the present invention can be used in flooded direct-seeded rice cultivation,
Alternatively, it can be used as a highly selective herbicide without chemical damage in flooded rice cultivation.
It has extremely high utility value. Furthermore, it exhibits high herbicidal activity over a long period of time and can control many weeds. As described above, the compound of the present invention has many excellent characteristics as a herbicide and is highly practical.

Claims (1)

[Claims] 1 General formula () (In the formula, A represents a halogen atom or a lower alkyl group, and B represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group having 2 or more carbon atoms.)
A carbamate derivative represented by 2 General formula () (In the formula, Y represents a hydrogen atom or a halocarbonyl group, and A represents a halogen atom or a lower alkyl group.) A phenol derivative represented by the general formula () (In the formula, Z is a halocarbonyl group when Y in the formula () is a hydrogen atom, and is a hydrogen atom when Y in the formula () is a halocarbonyl group. B is a lower alkyl group having 2 or more carbon atoms, a lower General formula (), which is characterized by reacting with an aniline derivative represented by an alkenyl group or a lower alkynyl group. (In the formula, A represents a halogen atom or a lower alkyl group, and B represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group having 2 or more carbon atoms.)
A method for producing a carbamate derivative represented by 3 General formula () (In the formula, A represents a halogen atom or a lower alkyl group, and B represents a lower alkyl group, a lower alkenyl group, or a lower alkynyl group having 2 or more carbon atoms.)
A herbicide characterized by containing a carbamate derivative represented by: