JPS5844642B2 - Cyclohexane derivative herbicide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the general formula (wherein R1 represents a lower alkyl group, and R2 represents a benzyl group, a lower alkoxycarbonyl lower alkyl group, or a lower alkoxy lower alkyl group).

) The present invention relates to a herbicide characterized by containing a novel cyclohexane-1,3-dione represented by the following as an active ingredient.

The object of the present invention is to obtain these compounds industrially advantageously and to provide a simple and highly effective herbicide.

The present inventors have synthesized a large number of cyclohexane-1,3 dione derivatives, and are currently investigating those suitable for the above-mentioned purpose.

) to the compound represented by the general formula % formula % (In the formula, R2 has the same meaning as defined above.

) was reacted with the compound represented by the general formula [
The compound represented by [I] can be obtained industrially advantageously, and it also shows extremely excellent herbicidal activity against weeds of the family Weeds, such as Psyllium japonica, Psyllium spp. They discovered that it has selectivity to be virtually harmless to broad-leaved crops, including azuki beans and soybeans, which are susceptible to chemical damage, and after conducting further biological and physicochemical research, they completed the present invention.

A herbicide containing a 4-hydroxy-6-methyl-α-pyrone derivative as an active ingredient is known from Patent Application Publication No. 46-16916, but this known compound cannot completely kill the weeds. One drawback of this herbicide is that it requires relatively high doses.

However, the compound of the present invention exhibits a sufficient herbicidal effect even in a smaller dose than known compounds.

Furthermore, the compounds of the present invention exhibit excellent herbicidal efficacy against weeds even when treated at any growth period, whether before or after germination.

The compound of the present invention can be applied to daikon radish, azuki bean, etc. even at a dose that completely kills, for example, the weed of the family Helicoptera, by foliage spraying.
No effect was observed on broad-leaved crops such as soybeans, peas, spinach, and beets, and even at a dose that completely inhibits the germination of crabgrass in the pre-emergence soil treatment of weeds, it had no effect on the seeds of broad-leaved crops. Herbicides are extremely safe against herbicide damage to broad-leaved crops, and can be applied over 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 farmed fish.

→x In the production of the compound of the present invention, the general formula CH
3-hydroxy-2-cyclohexene- represented by I)
The 1-ones and the amine represented by the general formula (III) 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.

As the reaction solvent, common organic solvents such as alcohol, acetone, ether, benzene, toluene, chloroform, acetic acid ester, dimethylformamide, acetonitrile, dimethyl sulfoxide, and tetrahydrofuran are used.

After 30 minutes to several hours of reaction, if necessary, the solvent is replaced and alkali extraction is performed, and the alkaline layer is acidified with hydrochloric acid, and the precipitated crystals or separated oil are separated by solvent extraction or one filtration to obtain the desired product.

After purification by recrystallization or column chromatography, the structure was confirmed by elemental analysis, IR spectrum, NMR spectrum, etc.

The compound of the present invention may have the following tautomeric structural formula.

Next, Table 1 shows examples of compounds produced by the method of the present invention.

Next, the method for producing the compound of the present invention will be explained in detail by giving production examples.

Production example 1 2-(1-benzyloxyaminopropylidene)-5,
5-dimethylcyclohexane-1,3-dione 78 g of 5.5-dimethyl-3-hydroxy-2-propionyl-2-cyclohexen-1-one and 8 g of benzyloxyamine hydrochloride were dissolved in 50 cc of ethanol, 15 c of aqueous ethanol containing 2.1 g of caustic soda;
c. is added dropwise at room temperature.

After reacting for 1 hour and 30 minutes at the same temperature, the precipitated Na
The Cl was filtered through once, and the ethanol was distilled off under reduced pressure.

A 5φ aqueous solution of caustic soda is added to the residue, and insoluble matter is extracted with ether.

When the alkaline layer is neutralized with hydrochloric acid, an oily substance is obtained.

This is extracted with chloroform, washed with water, dried over magnesium sulfate, and the chloroform is distilled off under reduced pressure to obtain a colorless oil.

If left for a while, it will crystallize, but if recrystallized with petroleum ether, the desired product as white crystals will be obtained.

Yield 66%, melting point 58-598C Production example 2 2-(1-ethoxycarbonylmethyloxyaminopropylidene)-5,5-dimethylcyclohexane-1,3
-dione 5.5-dimethyl-3-hydroxy-2-propionyl-2-cyclohexen-1-one 1°96 g (0.01
mol) and aminooxyacetic acid ethyl ester hydrochloride 1.
After dissolving 56 g (0.01 mol) in 3 Q cc of ethanol and adding an ethanol solution containing 0.68 g (0.01 mol) of sodium ethylate to neutralize the hydrochloride,
React overnight at room temperature.

Ethanol was distilled off from the reaction solution under reduced pressure, and the residue was dissolved in water and extracted with ether to obtain 2.8 g of a pale yellow liquid.

This is purified by silica gel column chromatography to give the desired product as a colorless transparent liquid.

Yield: 94 poly, nδ11. ．． 5019 Production Example 3 2-(1-methoxyethoxyaminopropylidene)-5
,5-dimethylcyclohexane-1,3-dione 1.96 g (0,01
mol) and methoxyethyloxyamine hydrochloride 1.2i
(0.01 mol) was dissolved in 30 cc of ethanol, an ethanol solution containing 0.68 g (0.01 mol) of sodium ethylate was added to neutralize the hydrochloride, and the mixture was allowed to react overnight at room temperature.

After the reaction is complete, ethanol is distilled off under reduced pressure, water is added to the residue to dissolve it, extracted with ether, and the solvent is distilled off to obtain 2.5 g of the desired product as a colorless transparent liquid.

Yield: 93.5%, n: 1.5100 The herbicide of the present invention contains one or two of the compounds represented by the general formula CI).
This can be achieved by containing the above as active ingredients.

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, emulsion, powder, granule, or the like.

Examples of solid carriers include talc, bentonite, clay, diatomaceous earth, 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 formulation mentioned above, but for example,
In wettable powders, 5 to 80%, preferably 10 to 60%;
In emulsions, 5 to 70%, preferably 20 to 60%;
For powders and granules, it is 0.5 to 30%, preferably 1 to 30%.
A concentration of 10% is used.

Wettable powders and emulsions obtained in this way can be diluted with water to a specified degree; diluted to a desired concentration to form a suspension or emulsion; powders and granules can be left as they are, and sprayed or mixed into the soil before weed germination. Treatment or foliar spray treatment after weed germination.

When actually applying the herbicide of the present invention, an appropriate amount of the active ingredient is applied in an amount of 10 g or more, preferably 30 g or more per 10 ares.

In addition, the herbicide of the present invention is a known bactericide, insecticide, acaricide,
It can also be used in combination with 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, and urea herbicides such as linuron and tribunyl. , heterocyclic herbicides such as pentacin, pyrazone, and renacil.

Next, some 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.

Example 1 Wettable powder compound 1 20 parts talc
Part 37 Keisou ±
37 parts alkyl sulfate soda
Mix 6 parts or more uniformly and finely crush the active ingredient 2.
A hydrating agent of 0 ratio was obtained.

Example 2 Emulsion Compound 2 40 parts xylene
35 parts dimethylformamide
15 parts polyoxyethylene phenyl ether At least 10 parts were mixed and dissolved to obtain an emulsion containing 40 qb of active ingredient.

Example 3 Granule compound 3 7 parts talc 38 parts clay
38 part bentonite
10 parts alkyl sulfate soda
After uniformly mixing 7 parts or more and pulverizing finely, the diameter is 0.
．． Granules were granulated into particles of 5 to 1.0 mm to obtain granules with an effective number of diameters of 7φ.

Next, test examples regarding the effect of the herbicide of the present invention will be shown.

Test Example 1 Flooded Soil Treatment Test A pot with a surface area of 60 cn was filled with soil, and about 60 millet seeds were sown thereon and lightly covered with soil, followed by a flooded state to the extent that the soil surface was moistened.

The emulsion of each test compound was diluted with water to prepare a predetermined concentration of drug ii*10 cc, which was poured into a pot and placed in a greenhouse.

Two weeks later, the growth status of the barnyard grass was investigated.

The growth status was expressed in 6 stages from O to 5, with O1 indicating the same level of growth as without treatment, and 5 indicating death or non-germination, and the results shown in Table 2 were obtained.

Test Example 2 Single-leaf stage treatment test A pot with a surface area of 60 cm was filled with soil, and approximately 50 grains of Japanese millet were sown thereon, lightly covered with soil, and grown in a greenhouse.

When the Japanese millet grows to the single-leaf stage, the water depth is approximately 3 cIIL.
Each pot was flooded with water, and a chemical solution of a predetermined concentration prepared by diluting an emulsion of each compound with water was poured into each pot.

Two weeks later, the growth status of the Japanese millet was investigated.

Expressing the growth state according to the same criteria as Test Example 1,
The results shown in Table 3 were obtained.

Test Example 3 Leaf Treatment Test Pots with a surface area of 100 cni were filled with soil, and seeds of crabgrass and pigweed were sown, lightly covered with soil, and grown in a greenhouse.

When the crabgrass grows to the 2-4 leaf stage, a predetermined concentration chemical solution prepared by diluting each test compound emulsion with water to 1001/1
The foliage was sprayed at a rate of 0a.

Two weeks later, the growth status of the crabgrass and pigweed was investigated, and the growth status was expressed according to the same criteria as in Test Example 1, and the results shown in Table 4 were obtained.

Claims (1)

[Scope of Claims] One or two compounds represented by the general formula 1 (wherein R1 represents a lower alkyl group, and R2 represents a benzyl group, a lower alkoxycarbonyl lower alkyl group, or a lower alkoxy lower alkyl group) A herbicide characterized by containing seeds or more as active ingredients.