JPH0313227B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel compound, a method for producing the compound, and its use, and more specifically, the general formula {In the formula, R ₁ is a hydrogen atom, a lower alkyl group or a lower alkylcarbamoyl group, R ₂ is a lower alkyl group, R ₃ is a lower alkyl group or a lower alkenyl group, and X is an oxygen atom or a formula S(O) n (however, n
indicates 0, 1, or 2. ) is shown. }, a metal salt thereof, a method for producing the same, and a selective herbicide containing the compound as an active ingredient. It has already been reported that 5-phenylcyclohexenone compounds similar to the compounds of the present invention have herbicidal activity against grass weeds in Japanese Patent Publication No. 55-2001 and Japanese Patent Application Laid-open No. 51-1989.
Described in No. 13756. However, the compounds of _the present invention in which the phenyl group is substituted with an R ₁ Although the herbicidal efficacy against grass weeds is at the same level, it
It has excellent selectivity. That is, all of the above-mentioned known compounds are suitable for controlling grass weeds such as crabgrass, oat, and sycamore in broad-leaved crops such as azuki beans, soybeans, cucumbers, and radish; It has been extremely difficult to apply this method to other crops, as it has extremely strong effects on other crops as well as grass weeds. However, while the compound of the present invention exhibits high weed activity against gramineous weeds (particularly oats, etc.) like known compounds, it has a specifically small effect on crops such as wheat and barley.
It shows high selectivity between crops such as wheat and barley and weeds of the grass family, and has characteristics different from already known agents specifically for grass family weeds. The present compound can be used to treat weeds before they emerge or to be sprayed on the foliage after they emerge, but the latter treatment method is more desirable in terms of herbicidal activity. The compound of the present invention has the general formula (wherein, R ₁ R ₂ and X have the same meanings as above) and the general formula R ₃ ONH ₂ () (wherein, R ₃ has the same meanings as above). The represented oxyamines are reacted in an inert solvent. The reaction temperature is from room temperature to the boiling point of the solvent used, preferably at room temperature or under mild heating conditions. Alcohol as a reaction solvent,
Common inert solvents such as ether, benzene, toluene, and chloroform are used. After 30 minutes to several hours of reaction, if necessary, the solvent is replaced, alkali extraction is performed, the alkali layer is made acidic with hydrochloric acid, and the precipitated crystals are separated to obtain the compound of the present invention. In producing the metal salt of the compound of the present invention, the compound represented by the general formula () and a caustic alkali such as caustic soda or caustic potash are mixed in water or an organic solvent such as acetone, methanol, ethanol, dimethylformamide, etc. A sodium salt or a potassium salt is obtained by mixing and reacting with heating if necessary. Next, the desired metal salt can be obtained by reacting the sodium salt or potassium salt with a salt of the desired metal in the same manner. Metal salts often precipitate or crystallize out in the above-mentioned solvents. Examples of metal salts that form metal salts with the compound represented by the general formula () include Ca, Mg, Ba,
Monovalents such as Ni, Mn, Co, Zn, Fe, Ag, Na, K, etc.
Salts of divalent or trivalent metals are used, such as chlorides, hydroxides, sulfates, nitrates, acetates, etc., which are soluble in water or the organic solvents mentioned above. Note that Ca ²⁺ salt can also be obtained by reacting the compound represented by the above general formula () with calcium hydroxide. Some of the metal salts of the present invention produced in this way do not show a clear melting point due to some chemical changes or decomposition at high temperatures, but they do not show a clear melting point due to a chemical change or decomposition at high temperatures. The formation of metal salts can be determined by changes in absorption intensity. That is, the raw material compound represented by the general formula () exhibits carbonyl group absorption at wave numbers of 1655 and 1605 cm ^-1 , while the metal salt exhibits absorption at longer wavelengths. Note that the obtained metal salt may retain water of crystallization, or may have an anion such as OH coordinating with the metal atom. The compound of the present invention was purified by recrystallization from an appropriate organic solvent if necessary, and the structure was determined from the results of measurements such as IR spectrum, NMR spectrum, and MASS spectrum. The compound of the present invention represented by the general formula () can have the tautomeric structure shown below. Next, the present invention will be explained in more detail with reference to Examples. Example 1 (Compound No. 4) 2-[1-(ethoxyimino)butyl]-3-hydroxy-5-[4-(methylthio-methyl)phenyl]-2-cyclohexen-1-one: 2-butyryl-3 -Hydroxy-5-[4-(methylthiomethyl)phenyl]-2-cyclohexen-1-one (1.2 g) was dissolved in methanol (10 ml) and ethoxyamine (0.5 g) was added at room temperature.
After standing overnight, the reaction solution was poured into ice water to make it acidic with hydrochloric acid, and extracted with chloroform. The chloroform solution was dried over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and the residue was reconsolidated with methanol to obtain 1 g of white crystals of the target product. mp 59-60℃ Example 2 (Compound No. 6) 2-[1-(ethoxyimino)butyl]-3-hydroxy-5-[4-(methylsulfonylmethyl)phenyl]-2-cyclohexen-1-one: 2-Butyryl-3-hydroxy-5-[4-(methylsulfonylmethyl)phenyl]-2-cyclohexen-1-one (1 g) was dissolved in chloroform (10
ml) and methanol (5 ml), and ethoxyamine (0.5 g) was added at room temperature. After standing overnight, the reaction solution was poured into ice water to make it acidic with hydrochloric acid, and the precipitated crystals were separated. By recrystallizing the crude crystals from methanol, 0.9 g of white crystals of the target product were obtained.
mp 121-123℃ Example 3 (Compound No. 8) 2-[1-(ethoxyimino)propyl]-3-
Hydroxy-5-[4-(hydroxymethyl)phenyl]-2-cyclohexen-1-one: 3-hydroxy-5-[4-(hydroxymethyl)phenyl]-2-propionyl-2-cyclohexen-1-one ( 4.4g) in methanol (10
ml) and added ethoxyamine (1.5 g) at room temperature. After standing overnight, the reaction solution was poured into ice water to make it aqueous with hydrochloric acid, and the precipitated crystals were separated. By recrystallizing the crude crystals from methanol, 2.5 g of white crystals of the target product were obtained. mp 104-105°C Table 1 shows representative examples of the compounds of the present invention.

[Table] The herbicide of the present invention contains one or more of the compounds represented by the above general formula () as an active ingredient,
It has a similar form to ordinary pesticides. That is, the active ingredient compound is generally used by mixing an appropriate amount with a carrier and preparing it in the form of a wettable powder, an aqueous solution, an emulsion, a flowable preparation, or the like. Examples of solid carriers include talc, white carbon, bentonite, clay, diatomaceous earth, and the like, and examples of liquid carriers include water, alcohol, benzene, xylene, kerosene, mineral oil, cyclohexane, cyclohexanone, dimethylformamide, and the like. In these formulations,
If necessary, a surfactant may be added to obtain a uniform and stable form. The concentration of the active ingredient in the herbicide of the present invention varies depending on the form of the preparation mentioned above, but for example, in a wettable powder it is 5 to 80%, preferably 30 to 60%; in an aqueous solution it is 70%. ~95%, preferably 80-90%: 5-70%, preferably 20-40% in emulsions: 10-70 in flowables
%, preferably from 20 to 50%. The wettable powders, aqueous solutions, and emulsions obtained in this way can be diluted with water to a predetermined concentration to form a suspension or emulsion, and the flowable agent can be diluted as it is or diluted with water to a predetermined concentration and suspended. It is treated as a suspension before or after weed germination. When actually applying the herbicide of the present invention, an appropriate amount of 5 g or more of the active ingredient is applied per 10 ares. The herbicide of the present invention can also be used in combination with known bactericides, insecticides, acaricides, herbicides, plant growth regulators, and the like. In particular, when used in combination with a herbicide, not only the amount of chemicals used can be reduced and labor savings can be achieved, but even higher effects can be expected due to the synergistic action of both chemicals. Agents suitable for use in combination with the herbicide of the present invention include atrazine agents,
Triazine herbicides such as terbutrin agents, urea herbicides such as Ipron agents and tribunyl agents, heterocyclic herbicides such as Bentazon agents, 2,4-D, MCPP
Examples include phenoxyalkane carboxylic acid herbicides such as , benzonitrile herbicides such as Ioxynil, and sulfonamide herbicides such as Green. Next, some formulation examples regarding the herbicide of the present invention will be shown, but the active ingredient compounds, additives, and addition ratios are not limited to these examples and can be varied within a wide range. Formulation example 1 Wettable powder Compound No. 3 50 parts White carbon 12 parts Diatomaceous earth 30 parts Sodium alkyl sulfate 8 parts The above are mixed uniformly and finely ground to form the active ingredients.
A 50% hydrating powder was obtained. Formulation Example 3 Emulsion Compound No. 7 20 parts Xylene 40 parts Dimethylformamide 30 parts Polyoxyethylene phenyl ether 10 parts The above ingredients were mixed and dissolved to obtain an emulsion containing 20% active ingredient. Next, test examples regarding the effect of the herbicide of the present invention will be shown. Test example 1 ^Two 100cm pots were filled with soil, and the surface layer was covered with crabgrass,
Wild oats, goldenrod and pigweed were sown separately and grown in a greenhouse. When the weeds reach a height of 5 to 10 cm, a chemical solution of a predetermined concentration (in this case 400,
200ppm) was sprayed onto the stems and leaves of each weed at a ratio of 100/10a and left in a greenhouse. On the 28th day after the chemical treatment, the growth status of each weed was inspected according to the following criteria, and the results shown in the second table were obtained. Investigation criteria Damage rate index 0: 0% 2: 20-29% 4: 40-49〃 6: 60-69〃 8: 80-89〃 10: 100〃 Also, the numbers 1, 3, 5, 7, 9 are 0 and 2 respectively,
Indicates intermediate values between 2 and 4, 4 and 6, 6 and 8, and 8 and 10.

【table】

Claims (1)

[Claims] 1. General formula {In the formula, R ₁ is a hydrogen atom, a lower alkyl group or a lower alkylcarbamoyl group, R ₂ is a lower alkyl group, R ₃ is a lower alkyl group or a lower alkenyl group, and X is an oxygen atom or a formula S(O) n (however, n
indicates 0, 1, or 2. ) is shown. } and its metal salt. 2 General formula {In the formula, R ₁ is a hydrogen atom, a lower alkyl group or a lower alkylcarbamoyl group, R ₂ is a lower alkyl group, and X is an oxygen atom or a compound of the formula S(O)n (where n
indicates 0, 1 or 2. ) is shown. } and a compound represented by the general formula R ₃ ONH ₂ (in the formula, R ₃ represents a lower alkyl group or a lower alkenyl group). A method for producing a compound represented by the formula (wherein R ₁ , R ₂ , R ₃ and X have the same meanings as above). 3 General formula {In the formula, R ₁ is a hydrogen atom, a lower alkyl group or a lower alkylcarbamoyl group, R ₂ is a lower alkyl group, R ₃ is a lower alkyl group or a lower alkenyl group, and X is an oxygen atom or a formula S(O) n (however, n
indicates 0, 1, or 2. ) is shown. } A selective herbicide characterized by containing a compound represented by and a metal salt thereof as active ingredients.