JPS5936601B2 - herbicide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the general formula (where R1 and R2 represent a lower alkyl group, R3 represents a lower alkyl group or a lower alkenyl group, and X represents a hydrogen atom).

) as an active ingredient.

The object of the present invention is to provide a herbicide that is simple and reliable, by obtaining the above compounds in an advantageous manner technically.

The inventors discovered that numerous 3-acyl-4-human Ix-6
-Alkyl-α-pyrone derivatives have been synthesized and biological tests have been conducted. By reacting the compounds with 0-lower alkyl or lower alkenylhydroquinamine, compound (II) (in the formula R1, R2, R3 and X are the same as shown above, and compound (III) is a tautomer.

) was obtained in good yield.

The present inventors have found that the compound represented by the general formula CI) can be industrially advantageously obtained by further reacting the compound (II) or (III) with terephthalic acid chloride, and that the compounds can be used for soil treatment, foliage, etc. Both spraying treatments show extremely excellent herbicide activity against weeds of the weed family such as sycamore, oats, and foxtail, and are especially effective against legumes such as adzuki beans and soybeans, which are susceptible to chemical damage by many other herbicides. They discovered that it has the selectivity of being almost harmless, and after conducting further biological and physical research, they completed the present invention.

Patent Application Publication Nos. 49-30533 and 49-75
No. 724, a herbicide containing a 4-acyloxy-6-methyl-α-pyrone derivative as an active ingredient is known.
One of the drawbacks of this herbicide is that a considerably large amount of the known compound is required to completely kill off the above-mentioned weeds.

Surprisingly, the compounds of the present invention exhibit sufficient herbicidal effects against various weeds even at a considerably lower dose than known compounds.

Furthermore, the compounds of the present invention exhibit excellent herbicidal effects on 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, there was no effect on the seeds of broad-leaved crops. It has a very high safety profile against herbicide-induced damage to broad-leaved crops, 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.

In the compound represented by the above general formula, X is a hydrogen atom, R
1 and R2 are ethyl or propyl, and R3 is ethyl or allyl (has an excellent effect).

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 compound represented by the general formula [■] or (III) 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, chytyl, 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 filtration, solvent distillation, solvent extraction, alkali washing, water washing, drying, and solvent distillation.

In addition, the obtained crystals are purified by recrystallization or column chromatography, and then subjected to elemental analysis, IR spectrum, N
The structure was confirmed by analysis results such as MR spectrum.

Next, representative examples of the compounds of the present invention are shown.

Compounds used as starting materials in the method of the invention [
A typical example of (2) or (III) is as follows.

3-(1-N-ethoxyaminoethylidene)-6-ethyl-3,4-dihydro 2H-pyran-2,4-dione 3-(1-N-ethoxyaminoethylidene)-6-nityl-3,4-dihydro -2H-pyran-2,4-dione 3-(1-N-ethoxyaminobutylidene)-6-nityl-3,4-dihydro-2H-pyran-2,4-dione 3-(1-N-ethoxyaminobutylidene) glopyritene)-6-methyl-3,4-dihydro-2H-pyran-2,4-dione 3-(1-N-ethoxyaminopropylidene)-6-propyl-3,4-dihydro-2H-pyran -2,4-dione 3-(1-N-ethoxyaminobutylidene)-6-propyl-3,4-dihydro-2H-hyph 7-2,4-dione 3-(1-N~allyloxyaminoethylidene )-6-
Nithyl-3,4-dihydro-2H-pyran-2,4-dione 3-(1-N-allyloxyaminopropylidene)-6
-Nityru-3,4-dihydro-2H-pyran-2,4-
Dione 3-(1-N-allyloxyaminobutylidene)-6-
Nithyl-3,4-dihydro-2H-pyran-2,4-dione 3-(1-N-allyloxyaminopropylidene)-6
-Methyl-3,4-dihydro-2H-pyran-2,4-
Dione 3-(1-N-allyloxyaminopropylidene)-6
-Propyl-3,4-dihydro-2H-pyran-2,4
-dione 3-(1-N-allyloxyaminobutylidene)-6-
Propyl-3,4-dihydro-2H-pyran-2,4-
Dione 3-(1-N-ethoxyaminopropylidene)=5-bromo-6-nityl-3,4-dihydro-2H-pyran-
2,4-dione 3-(1-N-allyloxyaminoethylidene)-5-
Bromo-6-methyl-3,4-dihydro-2H-pyran-2,4-dione Next, examples relating to the method of the present invention will be shown.

Example 1 BisC3-(N-Enginyl-xypropionimidoyl)-
6-Ethyl-2-oxo-2H-pyran-4-yl]terephthalate 3-(1-N-ethoxyaminopropylidene)-6-nityl-3,4-dihydro-2H-pyran=2,4-dione3. Add 0.6 P of sodium hydroxide and 21 nl of water to a solution of 6-ri dissolved in 40 acetone, and add 3
Stirred for 0 minutes.

Thereafter, 1.41 g of terephthalic acid chloride was added under ice-cooling, and the mixture was stirred at room temperature for 2 hours.

After the reaction, the acetone was distilled off, the residue was dissolved in ether, the ether layer was washed with a 4% NaOH aqueous solution, and then washed with water, the ether layer was dried over anhydrous magnesium sulfate, and the ether was distilled off to obtain white crystals. Obtained.

This was recrystallized with n-hexane/benzene to obtain the desired product 3.
I got 41.

(mp124-5°C) Example 2 Bis[3-(N-allyloxypropionimidoyl)
-6-ethyl-2-oxo-2H-pyran-4-yl]
Terephthalate 3-(1-N-allyloxyaminopropylidene)-6
-Nityru-3,4-dihydro-2H-pyran-2,4-
In a solution of 4.5 ml of dione dissolved in 40 ml of acetone,
An aqueous solution of 0.7 ff of sodium hydroxide dissolved in 2 parts of water was added, and the mixture was stirred for 30 minutes.

Thereafter, 1.81 g of terephthalic acid chloride was added under water cooling, and the mixture was stirred at room temperature for 2 hours.

Thereafter, the acetone was distilled off, the residue was dissolved in ether, the ether layer was washed with a 4% NaOH aqueous solution, then water, and the chietyl layer was dried over anhydrous magnesium sulfate, the ether was distilled off, and the residue was dissolved in n-hexane. - Recrystallization from benzene gave the desired product 4.41.

(mp63-5°C) The herbicide of the present invention has the general formula [I]
It is made by containing one or more of the compounds shown in □ as an active ingredient.

The active ingredient compound is generally used by mixing an appropriate amount with a carrier and preparing it in the form of an aqueous phase preparation, 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 preparation mentioned above, but for example, in a hydrating powder, it is 5 to 80%, preferably 10 to 80%.
60%: 5-70% in emulsions, preferably 20-70%
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; the powders and granules are sprayed or mixed into the soil before the germination of weeds; Alternatively, foliar spray treatment is applied 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 101 or more, preferably 25 or more grams per 10 are.

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 3 Wettable powder The compound of Example 2 50 parts Merck 21 parts Diatomaceous earth 21 parts Sodium alkyl sulfate 8 parts or more were mixed uniformly and finely ground to obtain a wettable powder containing 50% of the active ingredient.

Example 4 Emulsion The compound of Example 1 40 parts xylene 35 parts dimethylformamide 15 parts holoxyethylene phenyl ether At least 10 parts were mixed and dissolved to obtain an emulsion containing 40% of the active ingredient.

Example 5 Granule Compound of Example 1 7 parts Talc
38 part clay
38 part bentonite
10 parts alkyl sulfate soda
After uniformly mixing 7 parts or more and pulverizing it finely, granulating it into granules with a diameter of 0.5 to LOmm to obtain the active ingredient 7.
% granules were obtained.

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

Test Example 1 A 10 x 10 Crt'L vat was filled with soil, and crabgrass, oat, sycamore, and foxtail were sown on the surface layer.

The next day, a prescribed chemical solution prepared by diluting an emulsion of each test compound with water was sprayed onto the soil surface, and the soil was left to stand in a greenhouse.

The growth status of each weed was investigated 21 days after the chemical treatment, and the growth status was expressed in 6 stages from 0 to 6, with 0 indicating the same level of growth as without treatment and 5 indicating death or failure to germinate. The droplets shown in Table 1 were obtained.

Claims (1)

[Scope of Claims] 1 One or more compounds represented by the general formula (wherein R1 and R2 represent a lower alkyl group, R3 represents a lower alkyl group or lower alkenyl group, and X represents a hydrogen atom) A herbicide characterized by containing as an active ingredient.