JPS605596B2 - Herbicide manufacturing method - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a compound having a novel chemical structure, and more specifically, the general formula (where RI and R2 represent a lower alkyl group, R3 represents a lower alkyl group or a lower alkenyl group, and X represents a hydrogen atom). This is a method for producing a compound represented by Compounds produced according to the present invention are useful as herbicides. The purpose of the present invention is to obtain the compounds industrially advantageously,
The aim is to provide a simple and effective herbicide.
The present inventors discovered a number of 3-acyl-4-hydroxy-6
-Alkyl-Q-pyrone derivatives have been synthesized and biological tests have been conducted, and it has been found that by reacting the compounds with ○-lower alkyl or lower alkenyl hydroxyamine, the compound

[0] (in the formula, R1, R2, R3 and X are the same as those shown above, and the compound [blood] is a tautomer) was obtained in a good yield. The present inventors have prepared a compound [B] or [
By further reacting terephthalic acid chloride with terephthalic acid chloride, the compound represented by the general formula [1] can be industrially advantageously obtained, and furthermore, the compounds can be used in both soil treatment and foliar spraying on sycamore, sycamore, sycamore, and oat. It exhibits extremely excellent herbicide action against regular weeds such as foxtail grass, and is particularly selective in that it is almost harmless against legume crops such as adzuki beans and soybeans, which are susceptible to chemical damage caused by many other herbicides. After discovering this, they conducted further biological and physical research and completed the present invention. Patent application published 1977-305
No. 33 and No. 49-75724 disclose herbicides containing 4-acyloxy-6-methyl-Q-pyrone derivatives as active ingredients; One drawback of this herbicide is that it requires a fairly large dose. Surprisingly, the compounds of the present invention exhibit sufficient herbicidal effects against various weeds even at considerably lower doses than known compounds. Furthermore, the compounds of the present invention exhibit excellent herbicidal effects on weeds when treated at any stage of greening, whether before or after germination. The compound of the present invention can be applied to radish, azuki beans, soybeans, peas, spinach, etc. even at a dose that completely kills, for example, the weed of the family Helicoptera by foliage spraying.
There is no effect on broad-leaved crops such as beets, and even at a dose that completely inhibits the germination of crabgrass in soil treatment before weed germination, no effect is observed on the seeds of broad-leaved crops. Herbicides are extremely safe against herbicide damage, and can be applied in a wide range of application times, locations, and concentrations. Furthermore, the compounds of the present invention can be used safely without concerns about residual toxicity in soil or plants or acute toxicity to livestock and fish. Among the compounds represented by the above general formula, those in which x represents a hydrogen atom, RI and R2 represent ethyl or propyl, and R3 represents ethyl or allyl have particularly excellent effects. Furthermore, the compound of the present invention has superior stability compared to the above-mentioned known compounds, and requires less consideration of special conditions such as temperature and humidity during production, formulation, and storage. , a certain effect can be expected when spraying. In producing the compound of the present invention, the general formula

The compound represented by [0] or [m] is dissolved in a suitable solvent, and an alkali such as caustic soda or caustic potash is added to form an alkali metal salt. This is once separated from the reaction mixture or reacted as it is with terephthalic acid dichloride. As the reaction solvent, common organic solvents such as acetone, tether, alcohol, benzene, toluene, chloroform, and ethyl acetate are used.The reaction is preferably carried out at a temperature below room temperature, and requires a reaction time of about 15 minutes to 3 hours. After the reaction, a crystalline compound of the present invention is obtained by operations such as heating in an oven, distilling off the solvent, washing with water, extracting with a solvent, washing with an alkali, washing with water, drying, and distilling off the solvent. Further, the obtained crystals were purified by recrystallization or column chromatography, and then their structures were confirmed by analysis results such as elemental analysis, m-spectrum, and NMR spectrum. Next, representative examples of the compounds of the present invention are shown. Compounds used as starting materials in the method of the invention [
Typical examples of [D] or [m] are as follows. 3-(1-N-ethoxyaminoethylidene)-6-ethyl-3,4-dihyde. -2H-pyran-2,4-dione 3-(11N-ethoxyaminopropylidene)-6-ethyl-314-dihydro-2-pyran-2,4-dione 3-(11N-ethoxyaminobutylidene)-6- Ethyl-3,4-dihydro-2H-pyran-2,4-dione 3-(1-N-ethoxyaminopropylidene)-6'-methyl-3,4-dihydro-2H-pyran-2,4-dione 3-(1- N-ethoxyamine, nopropylidene)-6-propyl-3.
4-dihydro-2-pyran-2,4-dione 3-(1
(1N-ethoxyaminobutylidene)-6-propyl-3
・4-dihydro-2day-pyran-2,4-dione 31 (
1-N-allyloxyaminoethylidene)-6-ethyl-3,4-dihydro-pan-pyran-2,4-dione 3-
(1-N-allyloxyaminopropylidene)-6-ethyl-3,4-dihydro-pyran-2,4-dione 3-(1-N-allyloxyaminobutylidene)-6-
Ethyl-3,4-dihydro 2 days-pyran-2,4-dione 3-(1-N-allyloxyaminopropyridine)
-6-methyl-3,4-dihydro-pyran-2,4
-dione 3-(1-N-allyloxyaminopropylidene)-6-propyl-314-dihydro-2H-pyran-2,4-dione 3-(1-N-allyloxyaminobutylidene)-6-propyl-3. 4-dihydro-pan-pyran-2,4-dione Next, examples relating to the method of the present invention will be shown. Example 1 Bis[3-(N-ethoxypionimidoyl)-6-ethyl-2-oxo-pyran-4-yl]terephthalate 3-(1-N-ethoxyaminopropylidene)-6-ethyl-3,4-dihydro 2 Add 0.6 parts of caustic soda and 2 parts of water to a solution of 3.6 parts of pyran-2,4-dione dissolved in 40 parts of acetone.
I added the dissolved aqueous solution and let it sit for 30 minutes. Thereafter, 1.4 hours of terephthalic acid chloride was added under ice-cooling, and the mixture was allowed to stand for 2 hours at room temperature. After the reaction was completed, the acetone was removed, the residue was dissolved in ether, and the ether layer was
%-NaOH aqueous solution, followed by water washing, the table layer was dried over anhydrous magnesium sulfate, and the ether was removed to obtain white crystals. This was recrystallized from n-hexane/benzene to obtain the desired product 3.4. (mp124-5℃) Example 2 Bis[3-(N-allyloxypropionimidoyloxy)-6-ethyl-2-oxo-2H-pyran-4-yl)phthalate 3-(1-N-allyloxyaminopropylidene)- 6-ethyl-3,4-dihydro 2
To a solution of 4.5 parts of pyran-2,4-dione dissolved in 4 parts of acetone, an aqueous solution of 0.7 parts of caustic soda dissolved in 2 parts of water was added, and the mixture was worshiped for 30 minutes. Thereafter, 1.8 g of terephthalic acid chloride was added under ice cooling, and the mixture was rinsed at room temperature for 2 hours. After that, the acetone was distilled off, the residue was dissolved in ether, and the ether layer was dissolved in 4%-Na.
After washing with an OH aqueous solution and then water, the ether layer was dried over anhydrous magnesium sulfate, the ether was removed, and the residue was recrystallized from n-hexane-benzene to obtain the desired product 4.4. (mp63-500) The herbicide of the present invention contains one or more of the compounds represented by the above general formula [1] as an active ingredient. The active ingredient compound is mixed with a carrier in an appropriate amount according to the general formula, and prepared in the form of a wettable powder, emulsion, powder, granule, etc., and used.
Examples of solid carriers include talc, bentonite, clay, diatomaceous material, etc., and examples of liquid carriers include water, alcohol, benzene, xylene, kerosene, mineral oil, cyclohexane, cyclohexanone, dimethylformamide, and the like. If necessary, a surfactant may be added in order to obtain a uniform and stable form in these preparations. 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 the case of a wettable powder, it is 5 to 80%, preferably 10%.
~60%; in emulsions 5-70%, preferably 20
~60%: For powders and granules, a concentration of 0.5 to 30%, preferably 1 to 10% is used. The wettable powders and emulsions thus obtained are diluted with water to a predetermined concentration to form a suspension or emulsion; powders and granules can be sprayed or mixed into the soil before weed germination; Alternatively, foliar spray treatment is applied after weed germination. When actually applying the herbicide of the present invention, 10 active ingredients per 10 are? An appropriate amount of the above amount, preferably 25 ta or more, is applied. In addition, the herbicide of the present invention is a known bactericide, insecticide,
It can also be used in combination with acaricides, herbicides, plant growth regulators, etc. In particular, when used in combination with herbicides, not only can the amount of chemicals used be reduced and labor-saving, but even higher effects can be expected due to the synergistic action of both chemicals. Chemicals suitable for use in combination with the herbicide of the present invention include triazine herbicides such as simazine, propazine and promethrin, carbamate herbicides such as betanal, urea herbicides such as linuron and tribunyl, and pentazone. Examples of herbicides include double ring herbicides such as Pyrazone, Pyrazone, and Renacil. Next, some reference 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 reference examples and can be varied within a wide range. Reference example 2 Compound of wettable powder Example 2
21 parts alkyl sulfate soda
At least 8 parts were uniformly mixed and finely ground to obtain a wettable powder containing 50% of the active ingredient. Reference Example 2 Emulsion Compound of Example 1 4 base xylene 35 parts dimethylformamide 15 parts polyoxyethylene phenyl ether 1 or more were mixed and dissolved to obtain an emulsion containing 40% active ingredient. Reference Example 3 Compound of Granule Example 1 7 no Miyako Talc 38 parts Clay
38 parts pentonite 1 $ part alkyl sulfate soda 7 parts or more are mixed uniformly and finely ground, with a diameter of 0.5 to 1. It was granulated into granules containing 7% of the active ingredient. Next, test examples regarding the effect of the herbicide of the present invention will be shown. Test Example 1 A 10 x 10-sized pad was filled with soil, and crabgrass, hackberry, sycamore, and foxtail were sown on the surface layer. The next day, a prescribed chemical solution prepared by diluting an emulsion of each mystery compound with water was sprayed onto the soil surface, and the soil was allowed to settle in a greenhouse. The growth status of each weed was investigated on the 21st day after the chemical treatment, and the growth status was 0 to 5, with 0 indicating the same level of growth as without treatment, and 5 indicating death or non-germination.
The growth status was expressed in 6 stages, and the results shown in Table 1 were obtained. Table 1

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 and R^2 are lower alkyl groups, R^3
represents a lower alkyl group or a lower alkenyl group, and X represents a hydrogen atom. ) is reacted with terephthalic acid dichloride. There are general formulas ▲ mathematical formulas, chemical formulas, tables, etc. ▼ (wherein R^1, R^2, R^3 and X are as shown above) method for producing a compound represented by