JPH0363248A - Selective herbicide for paddy fields - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a selective herbicide for paddy fields characterized by containing an amine salt of enol of 2-benzoyl-1,3-cyclohexanedione as an active ingredient. .

[Conventional technology]

Conventionally, 2-(2'-nitrobenzoyl)-1,3-cyclohexanedione compound has been disclosed in B1-
152842 is known to be a common type of active herbicide. However, these compounds are highly harmful to paddy rice and are difficult to use as herbicides for paddy fields. Also, substituted 3-(substituted oxy)-2
- Benzoyl-cyclohexy-2-enones are described in Japanese Patent Application Publication No. 83-2947 as being non-selective type active herbicides, but they are not only selective for paddy rice but also for use in paddy fields. No use as a herbicide is disclosed.

[Problem to be solved by the invention]

Conventional 2-(2'-nitrobenzoyl)-1,1-cyclohexanedione compounds and their enol esters have great phytotoxicity to paddy rice, or are known as gramineous plant control agents. The problem was that its use as a herbicide for rice fields was completely unknown.

An object of the present invention is to provide a selective herbicide for paddy fields that has excellent herbicidal activity against grass weeds and causes less phytotoxicity to paddy rice.

[Means to solve the problem]

In order to achieve the above object, the present inventors have formulated the following general formula (
I) [1) [wherein R is a halogen atom, an alkyl group having 1 to 2 carbon atoms, an alkoxy group having 1 to 2 carbon atoms, a nitro group, a cyano group, a haloalkyl group having 1 to 2 carbon atoms, or R8
0- (wherein m is O or 2, and Ra is an alkyl group having 1 to 2 carbon atoms), R1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R1 and R2 together are an alkylene group having 2 to 5 carbon atoms, and R3 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R4 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R3 and R4 together are an oxo group, and R5 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R6 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R5 and R6 together are an alkylene group having 2 to 5 carbon atoms, and R7 and R8 are Regardless of each other (1) hydrogen atom, (2)
a halogen atom, (3) an alkyl group having 1 to 4 carbon atoms,
(4) alkoxy group having 1 to 4 carbon atoms, (5) trifluoromethyl group, (B) cyano group, (7) nitro group, (
8> C1-4 alkyl group, Rb is an integer; Rb is (a) a C1-4 alkyl group, (
b) 1 carbon atom substituted with halogen or cyano group
-4 alkyl group, (C) phenyl group or (d) benzyl group. ), (to)-NR' Rd (however,
R and Rd are independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ) , (11)RC(0
) -(However, R8 is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms.) , (
12) Defined. ) or (it)-N (R) C
(0) Rd (He and Rd are defined as above), and R9, R10 and R11 are independently (1) a hydrogen atom, (2) a carbon substituted with a hydroxyl group in some cases an alkyl group having a number of 1 to 1B, or (3) an alkenyl group having 1 to 4 carbon atoms, or an alkyl group having 2 carbon atoms, or an alkenyl group having 1 to 4 carbon atoms, or R9 and RlO together, optionally interrupted by an oxygen atom;
~5 is an alkylene group. The application of the compound represented by ] as a herbicide for paddy fields was investigated.

As a result, the compound of general formula (I) surprisingly found a completely new use as a herbicide for paddy fields, showing excellent selectivity between paddy rice and grass weeds. , we have completed the present invention.

The present invention will be explained in detail below.

The compound of general formula (1) according to the herbicide for paddy fields of the present invention can be prepared by a known method, for example, in Japanese Patent Application No. 83-2947.
It can be manufactured by applying the method described in . That is, the corresponding compound of the general formula (1) can be obtained by reacting 2-(substituted benzoyl)-1,3-cyclohexanedione with an amine in a suitable solvent. Next, a specific manufacturing example will be given.

Production example 2-(4'-chloro-2'-nitrobenzoyl)-1,
3-Cyclohexanedione8. Og and 3.82 ml of triethylamine in 100 ml of dichloromethane at room temperature.
Stir for 0 minutes. The resulting solution was concentrated under reduced pressure, and the resulting crude product was washed with diethyl ether to give the desired product quantitatively. (Melting point 116-117°C, recrystallized from methylene chloride-hexane) Note that 2-(4'-chloro-2'-nitrobenzoyl)-1,3-cyclohexanedione (hereinafter referred to as (referred to as a comparative compound) was produced according to the following reference example.

Reference example 4-chloro-2-nitrobenzoyl chloride 32.7
．． and L3-cyclohexanedione 1B, 7 g to 240
Dissolve in ml of methylene chloride. 27 ml of triethylamine was added dropwise and the resulting solution was stirred at room temperature for 1 hour. The solution was washed successively with 2N hydrochloric acid, 5% potassium carbonate solution, and saturated brine, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was dissolved in 100 ml of acetonitrile. 21 ml of triethylamine and 3.1 ml of acetone cyanohydrin were added, and the solution was stirred at room temperature for 1 hour. When diluted with ether and acidified with 1N hydrochloric acid, a precipitate was deposited. The resulting mixture was filtered to obtain the desired product (melting point 1
58-158°C) 29g was given. (Yield 6B%) Compounds obtained by the above production method and comparative compounds are shown in Table 1, but the compounds related to the herbicide for paddy fields of the present invention are not limited to these. The following description will be made using compound numbers in the table.

The compound according to the present invention may have the following tautomers, and these isomers are included in the compound according to the present invention.

The compound according to the present invention is a novel compound not described in any known literature.

The compound of the general formula [I] of the present invention (wherein R, R' to R9 are as described in the first paragraph of the section ``Means for Solving the Problems'') forms a salt with an amine. Compared to previous compounds, such as comparative compounds, it shows a selective herbicidal effect with significantly reduced phytotoxicity on paddy rice.
Common name for the genus Hae.

An annual weed of the Poaceae family. Typical harmful grass of paddy fields), Japanese cypress (an annual weed of the Cyperaceae family, a highly harmful grass of rice fields), Cyperus japonica (an annual weed of the Cyperaceae family, a harmful grass of paddy fields), and Cyperus (a perennial grass of the Cyperaceae family).

Occurs in wetlands, waterways, and rice fields. Typical perennial harmful grass of paddy fields),
It has a remarkable herbicidal effect on annual and perennial weeds in paddy fields, such as Urikawa (Omodaceae, a perennial harmful weed that occurs in rice fields, wetlands, and ditches), firefly, and cyperus (a perennial herb that occurs in Cyperaceae, paddy fields, wetlands, and ditches). It shows the characteristic that there is little phytotoxicity to paddy rice.

General formula of the present invention [■] (wherein, R, R' to R11
is as described above. ) compounds exhibit excellent herbicidal activity against weeds before emergence and during the growing season, so they can be used, for example, in pre-transplanting soil treatment of paddy rice seedlings, post-transplanting soil treatment, crop growing season soil treatment, pre-transplanting foliage treatment, and crops. It is useful as a herbicide for treating foliage during the growing season.

By the way, the herbicide of the present invention is generally formulated into a convenient form for use according to conventional methods for agricultural chemical formulations.

That is, the above compound is dissolved in an appropriate inert carrier by blending it in an appropriate ratio together with an auxiliary agent if necessary.
They may be separated, suspended, mixed, impregnated, adsorbed, or adhered to form an appropriate dosage form, such as a suspension, emulsion, solution, wettable powder, powder, granule, or tablet.

The inert carrier that can be used in the present invention may be either solid or liquid, and examples of materials that can be used as solid carriers include soybean flour, grain flour, wood flour, bark flour, saw flour, and tobacco powder. Plant powders such as stem flour, walnut flour, mist, fiber powder, and residue after extracting plant extracts; Textile products such as paper, cardboard, and sifted; Synthetic polymers such as crushed synthetic resins; Clays (e.g. kaolin, bentonite, acid clay), talcs (e.g. talc, hyrophyllite),
Silicas (for example, diatomaceous earth, crushed sand, mica, white carbon [synthetic highly dispersed silicic acid, also known as hydrated fine powder silicon or hydrated silicic acid, and some products contain calcium silicate as a main component]), activated carbon, sulfur powder, Examples include inorganic mineral powders such as pumice, calcined diatomaceous earth, crushed bricks, fly ash, sand, calcium carbonate, and calcium phosphate; chemical fertilizers such as ammonium sulfate, ammonium phosphorous, ammonium nitrate, urea, and ammonium chloride; compost; and the like. These are used alone or in the form of a mixture of 2M or more. Materials that can serve as liquid carriers are selected from those that themselves have solvent ability, as well as those that do not have solvent ability but can disperse the active ingredient compound with the help of an auxiliary agent, such as the following: However, these can be used alone or in a mixture of two or more;
Water, alcohols (e.g. methanol, ethanol, isopropanol, butanol, ethylene glycol),
Ketones (e.g. acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone), ethers (e.g. ethyl ether, dioxane, cellosolve, dipropyl ether, tetrahydrofuran), aliphatic hydrocarbons (e.g. gasoline, mineral oil)
, aromatic hydrocarbons (e.g. benzene, toluene, xylene, solvent naphtha, alkylnaphthalene), halogenated hydrocarbons (e.g. dichloroethane, chlorinated benzene, chloroform, carbon tetrachloride), esters (e.g. ethyl acetate, dibutyl phthalate). , diisopropyl phthalate, dioctyl phthalate), acid amides (e.g. dimethylformamide, diethylformamide, dimethylacetamide), nitriles (e.g. acetonitrile), dimethyl sulfoxide, etc.

The following may be mentioned as adjuvants.

These adjuvants are used depending on the purpose. In some cases, two or more adjuvants are used together. In other cases, no adjuvant may be used at all.

Surfactants are used for the purpose of emulsifying, dispersing, solubilizing or wetting the active ingredient compounds. Examples include: polyoxyethylene alkylaryl ether, polyoxyethylene alkyl ether, polyoxyethylene higher fatty acid ester, polyoxyethylene resin acid ester, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate , alkylaryl sulfone 112 salts, naphthalene sulfonic acid condensates, lignin sulfonates, higher alcohol sulfuric esters, etc. For the purpose of dispersion stabilization, adhesion, or binding of active ingredient compounds, the following may also be used. Good: casein, gelatin, starch, alginic acid, methylcellulose, carboxymethylcellulose,
Gum arabic, polyvinyl alcohol, pine oil, bran oil,
bentonite, lignin sulfonate, etc.

For the purpose of improving the flowability of solid products, the following may also be used: waxes, etc., stearates, phosphoric acid alkyl esters, etc.

The following may also be used as peptizers for suspendable products: naphthalene sulfonic acid condensates, condensed phosphates, etc.

It is also possible to add antifoaming agents such as silicone oils.

The combination of active ingredients can be adjusted as necessary.

Usually 0.2 to 20% (by weight) when used as a powder or granule, and 0.1 to 50% when used as an emulsion or wettable powder.
% (mill) is appropriate.

Next, examples of typical dosage forms will be given, but it goes without saying that the content of the active ingredient can be varied within the above-mentioned range.

"Parts" in the description indicate parts by weight.

Example 1 Wettable powder compound Nll 50 parts, diatomaceous earth 20 parts, clay 2
2 parts of white carbon, 2 parts of sodium lignin sulfonate, and 3 parts of sodium alkylnaphthalene sulfonate are mixed and ground to obtain a wettable powder containing 50% of the active ingredient.

Example 2 Granule compound: 20 parts 5 parts, bentonite 25 parts, talc 7 parts
0. (15 parts, dodecylbenzenesulfonic acid -72
1 part and 2 parts of sodium ligninsulfonate, and add about 2 parts of water.
After kneading with a mixing machine, the mixture is granulated through a granulator, and then dried and sized to obtain granules containing 0.35% of the active ingredient.

In order to kill or suppress the growth of various weeds, the herbicide of the present invention is applied to the weeds in an effective amount to kill or suppress the growth of the weeds, either as is or in the form of dilution or suspension as appropriate with water, etc. Or, when the emergence or growth of the weed is undesirable, it is used by applying it to the foliage or soil.

The amount of the herbicide of the present invention to be used depends on various factors, such as the purpose, target weeds, weed or crop emergence/growth conditions, weed emergence trends, weather, environmental conditions, dosage form, application method, application location, and application time. fluctuate.

When the herbicide of the present invention is used, for example, as a selective herbicide for paddy rice, the compound of the present invention or its salt may be applied in the range of 10 to 500 g per hectare, preferably in the range of 20 to 200 g. Just select and process.

When the herbicide of the present invention is used in combination with other herbicides, the dosage range of the compound of the present invention is even smaller, considering that in many cases it will be effective at a lower dose than when used alone. It is also possible to select from.

The herbicide of the present invention is particularly valuable as a treatment agent for weeds in paddy rice from before their emergence to during the growth period, but it can also be used with other herbicides to expand the target weed species and the suitable period for control, or to reduce the dosage. It is also possible to use it in combination with other materials, which falls within the scope of the present invention.

[Effects of the present invention]

The herbicide of the present invention can selectively control paddy field weeds with significantly reduced phytotoxicity to paddy rice. Test examples are shown below, but it goes without saying that the present invention is not limited to these.

Test Example 1 Paddy soil was plowed into a Wagner pot of /5oooa, and the flooding method was set to 4 cm. Seeds of Japanese wildflower, Japanese cypress, Japanese cypress, and firefly are sown.
Embed the tubers of Urikawa, Mizugaya Tsuri, and Kurogwai,
Two-leaf stage rice (variety: Koshihikari) was transplanted to 6 plants per pot (3 plants of 1011 plants, 3 plants of 3 cm plants). On day 10 after transplantation, granules prepared according to Example 2 were applied to the water surface. A water leakage operation of 3 cm/day was performed on the day after the treatment and the day after. At day 0, 21 days after the treatment, observation and evaluation were performed according to the following criteria.

The results are shown in Table 2.

Claims (4)

[Claims] (1) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ [In the formula, R is a halogen atom, an alkyl group having 1 to 2 carbon atoms, an alkoxy group having 1 to 2 carbon atoms, a nitro group, a cyano group, Haloalkyl group having 1 to 2 carbon atoms or R^
aSO_m- (where m is 0 or 2 and R^
a is an alkyl group having 1 to 2 carbon atoms. ), R^1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R^2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R^1 and R^2 together represent an alkylene group having 2 to 5 carbon atoms, R^3 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R^4 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. is an alkyl group, or R^3 and R^4 together are an oxo group, and R^
5 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R^6 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, or R^5 and R^6 are combined. It is an alkylene group having 2 to 5 carbon atoms, and R^7 and R^8 are independently (1) a hydrogen atom, (
2) halogen atom, (3) alkyl group having 1 to 4 carbon atoms, (4) alkoxy group having 1 to 4 carbon atoms, (5) trifluoromethyl group, (6) cyano group, (7) nitro group , (8) haloalkyl group having 1 to 4 carbon atoms, (9) R
^bSO_n- (where n is an integer of 0, 1 or 2, and R^b is (a) an alkyl group having 1 to 4 carbon atoms, (b) 1 carbon atom substituted with a halogen or cyano group) -4 alkyl group, (c) phenyl group or (d)
It is a benzyl group. ), (10) -NR^cR^d (However, R^c and R^d are independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.), (11)
R^eC(O)- (However, R^e is an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms.), (12) SO_2NR^cR^d (However, R ^
c and R^d are defined as above. )or(
13) -N(R^c)C(O)R^d (where R^c and R^d are defined as above), and R^9, R^1^0 and R ^1^1 is independently (1) a hydrogen atom, (2) an alkyl group having 1 to 16 carbon atoms, optionally substituted with a hydroxyl group, or (3) an alkenyl group having 1 to 4 carbon atoms, or R^9 and R^1
Together with ^0, it is an alkylene group having 2 to 5 carbon atoms, optionally interrupted by an oxygen atom. ] A compound represented by (2) A selective herbicide for paddy fields, which contains the compound according to claim 1 as an active ingredient. (3) General formula according to claim 1 (R is a nitro group, R
^1 to R^6 are hydrogen atoms, R^7 is a 4-chlorine atom, R^8 is a hydrogen atom, R^9 to R
^1^1 is as defined in claim 1. ) compounds. (4) A selective herbicide for paddy fields, which contains the compound according to claim 3 as an active ingredient.