JPS6042201B2 - 2-cyclohexen-1-one derivatives and herbicides - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula σ-C-R, where R1 is a C1-5 alkyl group, R2 is a C1-3 alkyl group, or a C2-4 alkenyl group. , R3 is C
, ~0 alkyl group, R is a C1-a alkyl group, phenyl group, or phenyl group substituted with a halogen atom, x is a different or similar C substituted with a hydrogen atom of the cyclohexene ring, ~0 alkyl group, In the alkyl group, n represents 1 or 2.

) is a herbicide characterized by containing a novel cyclohexen-1-one derivative 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 cyclohexen-1-one derivatives, and while searching for one suitable for the above purpose, the general formula '(wherein Rl, R2, R3, X and n are the same as shown above) represents the meaning of

) to the compound represented by the general formula Y-C-R or (RCO)20 [■] (wherein R represents the same meaning as shown above, and Y represents a halogen atom.

) The cyclohexen-1-one derivative represented by the general formula [1] can be industrially advantageously obtained by reacting an aliphatic or aromatic acyl halide or an acid anhydride represented by the formula [1]. The present invention was completed based on the discovery that compounds exhibit strong herbicidal activity against certain types of weeds.

In producing the compound of the present invention, the compound represented by the above general formula [■] is dissolved in an appropriate solvent, and therefore, in the method of the present invention, the compound represented by the above general formula [■] is alkoxycarbonyl Although it can undergo a dehydrochlorination reaction with the hydroxyl group at the 2- and 4-positions of the group, due to steric hindrance of the alkoxycarbonyl group, it reacts with the hydroxyl group at the 4-position located at a distant position rather than at the adjacent position. However, a small amount of alkali such as 2-position isomer* caustic soda or caustic potash is added to form an alkali metal salt. Once this is separated from the reaction mixture, or as it is, it is reacted with an aliphatic or aromatic acyl halide or acid anhydride represented by the general formula [■]. Common organic solvents such as acetone, ether, alcohol, benzene, toluene, chloroform, and ethyl acetate are used as reaction solvents, and the reaction temperature is -2
The reaction is carried out at a temperature from 0° C. to the boiling point of the solvent used, preferably below room temperature. After a reaction time of about 1 hour to 1 hour, if necessary, after treatment such as solvent replacement or solvent extraction, washing with alkali, then water, drying, and distilling off the solvent under reduced pressure produces a crystalline or The desired compound represented by the general formula [1] is obtained as a liquid.

In addition, the product is purified by recrystallization or column chromatography, and then subjected to elemental analysis, IR spectrum, NMR analysis, etc.
The structure was confirmed by analysis results such as spectra.

The compound represented by the general formula [■] can have the following isomeric structural formula based on tautomerism.

It can also be produced by the body.

Next, a production example using the method of the present invention will be shown.

Production Example 1 2-(N-7toxypropionimidoyl-3-acetoxy5,5-dimethyl-6-ethoxycarbonyl-2-cyclohexen-1-one 3.1V of 2-(1-ethoxyaminopropylidene)-4 -Ethoxycarbonyl-5,5-dimethylcyclohexane-1,3-dione was suspended in 50 TrLL of acetone, 0.8 y of acetyl chloride was added at room temperature, and the suspension was kept under stirring.

After 3 hours, stirring was stopped, and the reaction mixture was poured into ice water and extracted with chloroform. The chloroform layer was washed with IN caustic soda solution and dried over magnesium sulfate. Chloroform was removed under reduced pressure to obtain 1.2y of the target product as an oil. Refractive index Nb8l. 4848 Production Example 2 2-(N-allyloxypropionimidoyl)-3-
(p-chlorobenzoyloxy)-5,5-dimethyl-6-ethoxycarbonyl-2-cyclohexen-1-one 3.2y of 2-(1-allyloxyaminopropylidene)-4-ethoxycarbonyl-5,5- Dimethylcyclohexane-1,3-dione was dissolved in 50 ml of acetone, and 0 of caustic soda was added while stirring at room temperature.

1 ml of a caustic soda aqueous solution containing 4y and then 1.7y of P-chlorobenzoyl chloride were added dropwise.

After stirring for 5 hours, the reaction mixture was poured into ice water and treated in the same manner as in Production Example 1 to obtain the target product 2.3y in the form of an oil. Refractive index n: 21.5348 Production example 3 2-(N-ethoxybutylimidoyl)-3-benzoyloxy5,5-dimethyl-6-methoxycarbonyl-2-cyclohexen-1-one 3.1y 2-( N-ethoxyaminobutylidene)-4-methoxycarbonyl-5,5-dimethylcyclohexane-1,3-dione 5
The solution was dissolved in 0 mL of acetone, and while stirring at room temperature, 1 ml of an aqueous solution of caustic soda containing 0.4 V of caustic soda was added dropwise, followed by 1.4 q of benzoyl chloride.

After stirring for 5 hours, the reaction mixture was poured into ice water and treated in the same manner as in Production Example 1 to obtain 2.8q of the target product in the form of an oil.
I got it. Refractive index n 4.51.5165 Production example 42-(
N-allyloxypropionimidoyl)-3-benzoyloxy-6-ethoxycarbonyl-6-ethyl-2
-Cyclohexen-1-one 1.6y of 2-(1-allyloxyaminopropylidene)-4-ethoxycarbonyl-4-ethyl cyclohexane-1,3-dione was dissolved in 30ml of acetone and stirred at room temperature. While doing so, 1 ml of a caustic soda aqueous solution containing 0.3 y of caustic soda and then 0.7 q of benzoyl chloride were each added dropwise.

After continuing to stir for 3 hours, the reaction mixture was poured into ice water and treated in the same manner as in Production Example 1 to obtain an oily target product 1.
I got 3q.

Refractive index NL4l. 5225 Table 1 shows representative examples of the compounds of the present invention. The compound of the present invention obtained by the above method exhibits an extremely excellent selective herbicidal effect on weeds of the family Weeds, such as Psyllium annuus, Psyllium spp. It has the property of being almost harmless to legumes such as azuki beans and soybeans, as well as broad-leaved crops such as heat, which are susceptible to chemical damage caused by pesticides.

A herbicide containing a 4-acetoxy-6-methyl-α-pyrone derivative as an active ingredient has already been made known by the present inventors as Patent Application Publication No. 30533/1983.
One of the drawbacks of this herbicide is that a considerably large amount of the herbicide is required in order to completely kill off the above-mentioned weeds.

That is, according to the description in the above-mentioned publication and the follow-up tests conducted by the present inventors, in actual use, the expected effect can be obtained with a dose of 500 y of active ingredient per 10 are;
If the dosage is less than 50q, it will not be possible to kill all the weeds, and the complete effect will not be obtained. Surprisingly, the compound of the present invention has a molecular weight of 112 to
There are some that exhibit sufficient herbicidal effects even at dosages of 115 or less.

Furthermore, the present invention exhibits excellent herbicidal effects without causing chemical damage to cultivated crops even when treated against weeds at any growth period, whether before or after germination. The compound of the present invention has almost no effect on broad-leaved crops such as daikon radish, adzuki beans, soybeans, peas, spinach, and heat, even if the compound of the present invention is sprayed on the leaves at a dose that completely kills the grasshopper weed. In addition, in pre-emergence soil treatment for weeds, even at doses that completely inhibit the germination of crabgrass, there is almost no effect on the seeds of broad-leaved crops, indicating that herbicides are extremely safe against damage caused by herbicides to broad-leaved crops. The application also depends on the application time, application location, and application concentration. It can be used extremely widely.

In addition, since the compound of the present invention is used at a low concentration, there is no concern about residual toxicity in plants or acute toxicity to livestock and fish, and it can be used safely. The herbicide of the present invention can be used in the form of a commonly used concentration, such as a wettable powder, by mixing an appropriate amount of one or more of the compounds represented by the general formula [1] with a carrier. It is used in the form of emulsions, powders, granules, etc.

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 preparation method is similar to that of ordinary agricultural chemicals, but for example, for wettable powders, appropriate amounts of active ingredients and solids are uniformly mixed by adding a surfactant if necessary. It is obtained by finely pulverizing it.

The active ingredient content in the wettable powder is about 5-80%, preferably 1
0 to 60% is appropriate. The emulsion is obtained by sufficiently dissolving an appropriate amount of the active ingredient in the above-mentioned liquid carrier with or without the addition of a surfactant, and the active ingredient content is preferably about 5 to 70%, particularly 20 to 60%. . For granules, appropriate amounts of the active ingredient and a solid carrier are uniformly mixed with a surfactant if necessary, finely pulverized, and then granulated using a granulator with a diameter of 0.1 to 1.5 T. A method of forming granules with a Rml, preferably 0.5 to 1.0 wrm is carried out.
A powder is also obtained by a method similar to the preparation of wettable powders. The amount of active ingredient in granules and powders is approximately 0.5 to 30%, preferably 1 to 10%. The wettable powders and emulsions thus obtained are diluted with water to a predetermined concentration to form a suspension or emulsion, and the powders and granules are subjected to soil surface treatment or soil mixing treatment before weed germination. Alternatively, foliar spray treatment is applied after weed germination.

When actually applying the herbicide of the present invention, an appropriate amount of 10q or more of the active ingredient per 10 ares, preferably 25f or more of the active ingredient is applied. In addition, the herbicide of the present invention is a known fungicide,
It can also be used in combination with insecticides, 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. Known herbicides suitable for use in combination with the herbicide of the present invention include triazine herbicides such as simazine, propasin, and promethrin, carpamate herbicides such as petanal, and urea herbicides such as linyuron and tribunyl. Heterocyclic herbicides such as Bentazone, Pyrazone, Renacyl, etc. 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 Emulsion compound 15(2) xylene
4z■Polyoxyethylene phenyl ether 8
An emulsion containing 50% of the active ingredient was obtained by mixing and dissolving more than 100% of the active ingredients.

Example 2 Wettable powder compound 23C8 Silica earth 56 parts Higher alcohol sulfate ester 8 parts White carbon 6 parts or more are mixed uniformly,
The powder was finely ground to obtain a wettable powder containing 30% of the active ingredient.

Example 3 Granules: 33 parts of the compound, 97 parts or more of the compound were uniformly mixed and pulverized, and the diameter was 0.5 to 1.0 TWL using a granulator.
The mixture was granulated to obtain granules containing 3% of the active ingredient.

Next, test examples will be shown to demonstrate the effectiveness of the herbicide of the present invention.
Test Example 1 Flooded Soil Treatment A test pot is filled with soil, and approximately 6 @1. After sowing and lightly covering the soil, the soil was flooded with water to the extent that the soil surface was moistened.

10 cc of a chemical solution of a predetermined concentration prepared by diluting an emulsion of each test compound with water was poured into the pot. Two weeks later, the growth status of the barnyard grass was investigated.

The growth status was expressed in 6 stages from 0 to 5, with 0 being the same growth level as without treatment, and 5 being dead or non-germinated, and the results shown in Table 2 were obtained. JP-A-49-30533 as a control compound
3-(N-ethoxyacetimidoyl)-4-acetoxy6-methyl-α-pyrone described in No.

Test Example 2 Stem and Leaf Treatment A test pot was filled with soil, and seeds of crabgrass were sown, lightly covered with soil, and grown in a greenhouse.

When the crabgrass grows to the 2-4 leaf stage, 100 e
The foliage was sprayed at a rate of /103**. Three weeks later, the growth status of the crabgrass was investigated, and the growth status was expressed according to the same criteria as Test Example 1, and the results shown in Table 3 were obtained.

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 represents an alkyl group of C_1_-_5,
is an alkyl group of C_1_-_3 or an alkenyl group of C_2_-_4, R^3 is an alkyl group of C_1_-_4, R is an alkyl group of C_1_-_3, a phenyl group, or a phenyl group substituted with a halogen atom , X is a different or similar C substituted for the hydrogen atom of the cyclohexene ring
In the alkyl group of _1_ to _4, n represents 1 or 2. A herbicide characterized by containing one or more of the compounds shown in ) as an active ingredient.