JPH01313404A - Herbicidal composition - Google Patents

Abstract

PURPOSE: To obtain a herbicidal composition especially effective for controlling weeds in transplanted rice, comprising a mixture of a pyridinecarbothioic diester and an acetamide. CONSTITUTION: This herbicidal composition comprises a mixture of (A) 2- difluoroethyl-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinedicar bothioic S,S- dimethyl ester and (B) N-(α,α-dimethylbenzyl)-α-bromo-tert-butylacetamide in the weight ratio A/B of (0.1:1) to (0.03:1). The amounts of application of these ingredients per ha are as follows: A=0.005-0.28 (esp. 0.04-0.20)kg, B=0.1-3 (esp. 0.9-1.5)kg. High unit activity, low solubility to water and high adsorbability to soil of this composition affords reduced water pollution.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to novel herbicide combinations that are particularly effective for controlling undesirable plants in transplanted rice crops.

More specifically, the present invention relates to 2-(difluoromethyl)
-4-(2-methylpropyl)-6-(trifluoromethyl, l-3,5-pyridinedicarbothioic acid S, S-dimethyl ester and N-(α,α-dimethylbenzyl)-
It relates to a method of use in which α-bromo-tart-butylacetamide is applied separately or as a mixture.

(Conventional technology).

Herbicidal pyridine dicarboxylate derivatives are known in the patent literature. See, for example, JP-A-61-158,965 and JP-A-60-78,965.

Herbicidal N-benzylhaloacetamide compounds are likewise known. See, for example, % Application No. 53/140800, No. 53/139069 and No. 56/115588.

The inventors have discovered that 2-difluoromethyl-4-(2-methylpropyl)-6-()! 7 fluoromether, l-3,
5-Pyridinedicarbotheoic acid S,S-di)f ester and N-(α,α-dimethylbenzyl)-α-bromo-t
ert-butylacetamide, when applied as a mixture or separately, has been found to be particularly effective in controlling undesirable plants commonly found in transplanted rice crops. These compounds are each used in a ratio of about 0.1:1 to about 0.03:1, and the pyridinedicarpoteoate compound is used in a ratio of about 0.28 to about 0.00.
The N-benzylhaloacetamide compound is applied to the plant field at a rate of 5 kg/hectare from about 0.1 to about 6 to 97 hectares. A particularly suitable application rate is from about 0.20 to about 0.20 to about 0.20.
04 kg/ha and 0.9 to about 1.5 to 9/ha for N-benzylhaloacetamide compounds.

Examples are provided below to illustrate how each of these two compounds can be made from commercially available starting compounds.

Example 1 and Step A: Preparation of methyl trifluoroacetoacetate (MTFAA) (17
8,9Ii, 0.915 mol) and piperidine (0,
44 g, 5.16
15 mol) was added in 3 minutes. An exotherm occurred and the temperature rose to 108°C in 6 minutes. The reaction mixture was kept at 108°C for 2 hours and then cooled to 60°C. Furthermore, 4.45 II (0
,051 mol) of isovaleraldehyde was added and the mixture was held at 83° C. for 1.5 hours.

The reaction mixture was left at room temperature overnight (12 hours) and 80.4
g of toluene and then stirred and heated at 56° C. for 2 hours. This reaction mixture was added with ammonia gas (16,2
11,0,952 mol) was introduced in 1 hour and 40 minutes. The mixture was further diluted with 91 g toluene and added with 4.3 I
I (0,253 mol) of ammonia was introduced in 25 minutes. The mixture was cooled to 5° C. in a water bath and excess ammonia was purged by bubbling N2 gas for 20 minutes. 409 sulfuric acid was added to the reaction mixture. The temperature rose to 45°C due to exotherm.

After cooling to 65℃, continue stirring for several minutes at 65℃.
01 g of sulfuric acid was added. The reaction mixture was stirred for 20 minutes at 3°C and poured onto 1 kg of ice. The mixture was stirred with 220 g of toluene. The toluene layer was separated, and the aqueous layer was extracted once with 280 g of toluene and twice with 600 M toluene. The combined toluene layers were washed with brine and concentrated in vacuo to give 182.2 g of an oil. This oil was dissolved in 500 M of methylene chloride, washed successively with 250 M of saturated aqueous NaHCO3 solution and 600 M of brine, and dried.
) and concentrated in vacuo to give 179.4 # of dihydropyridine as an oil. The assay value of the product was 86%, MT
The total yield from FAA was 86%.

Step B A mixture of compound 23.34.9 (0.0514 mol) of Step A above, 11.11 g (0.0599 mol) of tributylamine and 50 N of toluene is kept under reflux for 1 hour and diluted with 50 parts of cooled toluene. did.

The toluene solution was mixed with water, 6 N HCl
(2×100 JIA) and brine (1001 u) and concentrated in vacuo. The residue was tube distilled at 1 Torr. First distillate (0.25 g of 74% pure product)'
After excluding t=19.17,! i' (86,2%
) product with a purity of 85.6- was collected. pot residue (
1,49 g) in ether and 50 g of saturated NaH.
Extracted with CO3. The aqueous layer was made acidic with concentrated hydrochloric acid. The oily precipitate was extracted with ether. The ether extract was dried and concentrated in vacuo to yield 1.13 g of residue, which was dissolved in DMF.
Methyl diiodide in 20M 8.49 and 2C030,4
Reacted with 7,9 to give 96% pure product 0.9511
(4,8chi) was obtained. The overall yield of product from MTFAA was 74%.

Step C Hydrolysis to diacid and conversion to diacid chloride Stirrer, condenser and temperature regulator Gold bias * In a 22 t flask, 7192 & (57,68 mol) of 45-KO
H solution and 4 tON20 were added, and then the mixture 6178.5F (16,73
mol) was added with stirring over about 5-10 minutes. The mixture was heated to reflux (94°C) and the hydrolysis was essentially complete after 21 hours of reflux. The reaction mixture was cooled to about 45° C. and divided in half (about 6 parts of salt solution in each half). Batch 1 - Diluted with 1 t of N20, stirred well for about 15 minutes, and then extracted with 5 t of methylene chloride. The phases were separated and the basic aqueous phase was acidified to ca. 2 with concentrated HC2. The material was cooled to -4°C and precipitated as a diacid brown solid. This solid was washed with water. The overall yield was 88 cm.

Add the above diacid 4374.8.9 under N2 in a 221 flask.
(12.82 mol) and 6 t'fr of toluene were added. Then, thionyl chloride 57
37. ! i'(3517N) C48, 2 mol) was added stepwise. The mixture was heated to boiling and refluxed for about 40 hours, then cooled to about 65°C and heated to 65°0°20-60°C.
torr and finally concentrated on a rotary evaporator at 45° C. and 0.2 torr.

Finally, the product is converted to about 1ki9 silica glue (60-20
0 mesh). The column was wetted with hexane, the crude diacid chloride was dissolved in the minimum amount of hexane, and the product was eluted with hexane.

Step D 221 Add newly opened tetrahydrofuran 6 to the flask.
Sodium salt of t and methyl mercaptan 1936.
1 # (27.6 mol) was added under 1 Nz. solution to 0
8, and 4295.7 g (11.36 mol) of the diacid chloride obtained from Step C was added while keeping the total temperature below 40°. The reaction was complete after one day. The flask was completely cooled, and 6 tons of ether, 11 tons of 12N HCl, and 4 tons of water were added. All layers were separated, and the organic phase was washed with 4 t of water and 4 t of saturated NaCt solution.
Washed once with t. The solvent was removed under vacuum. The crude product was diluted 2:1 with hexane and passed through a 6' length x 5' diameter silica glu column eluting with hexane.

After removing the solvent, 4021.0 g (88%) was obtained. This product was recrystallized from hexane to 6579.49 (78,5
h), a melting point of 57-62° was obtained.

Example 2 Method 1: In a 2001d four-neck flask, add benzene (100
111A), α, α-dimethylbenzylamine (9 g)
and triethylamine (7,4&) and α-bromo-tert-zoteracetelchloride (1
4,59) k, was added dropwise while stirring at room temperature. The stirring party continued for three hours. The reaction mixture was washed with sonic water to remove triethylamine hydrochloride. After drying the benzene layer over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure. The resulting residue was recrystallized from ethanol to give 15.39 N-(α, α
-dimethylbenzyl)-α-zolomotert-7”
Tylacetamide, melting point 182°-186° (ll-obtained).

Method 2: In a 5001d four-necked flask, methyl isobutyl ketone (1501d), α,α-dimethylbenzylamine (33.8 g) and trietheramine (27,
8g) Add α-bromo-tert-butylacetylbromide (64.5g) and stir at room temperature.
' was added dropwise. Stirring continued for a total of 6 hours. After the reaction was complete, water (20[ml]) was added and the reaction mixture was slowly heated to remove the methyl isobutyl ketone and then cooled to room temperature. The precipitated crystals were filtered, washed with water, dried, and recrystallized from ethanol to give N-(α,α-dimethylbenzyl).
-α-zolomo tert-butylacetamide (61,
5P) was obtained.

Method 3: In a 200 #lJ four-necked flask, add α-bromo.
Add tert-butyl acetic acid (9.8 g) and benzene (50 g) to a gold pot, stir at room temperature, then add pyridine (50 g).
M) and α,α-dimethylbenzylamine (6,9 g
) ' was added dropwise. Furthermore, dicyclohexylcarbodiimide (10.8 g)' (Il-) was added to this, and the mixture was heated at 60° to 70°
The reaction was continued for 6 hours at °C and then cooled. The solvent was removed under reduced pressure and the residue was extracted with hot benzene. The benzene extract was concentrated by distillation, and the residue was recrystallized from ethanol to give N-(α,α-dimethylbenzyl)-α-bromo-
tert-i thylacetamide (10,89) kW.

Many Japanese scientists have predicted that rice field weeds will become uncontrollable in the future. The consensus is that the following four types of weeds are the best in the future! The main reason why it was chosen as an important weed is its strong ability to regenerate in rice fields. Other weeds that are currently a problem, such as S.

pygmaea, S. trifolia,
E. kuroguwai reproduces only through whole vegetative embryos. Therefore, once effective herbicides are developed against them, it is expected that their populations will be significantly reduced within a short period of time. However, it is very difficult to completely control these four important weeds, and if only one plant survives in one paddy field,
The following year, the population increases and herbicide application becomes absolutely necessary. Several weeds other than these four major weed species are currently problematic, and new herbicides are required to control them.

However, these new herbicides must control the four weeds mentioned above. In other words, these four weeds represent a minimal number of weeds that cannot be easily controlled by newer commercial herbicides.

This current status regarding new herbicide development is summarized by E.

crus-gallj, f Compounds that can control are E,
It shows that it has great commercial potential as a mixture with herbicides to control other major weeds besides C. crus-gallj.

There is currently growing environmental concern about the use of herbicides, and one of the main concerns is herbicide contamination of rivers and tap water. The method of reducing water pollution caused by herbicides is said to be to reduce the application rate of herbicides and to prevent herbicides from migrating in the soil. Therefore, compounds with high unit activity, low water solubility and high soil adsorption could solve or alleviate this problem and at the same time serve as effective rice herbicides.

As mentioned above, the herbicide combination according to the invention is particularly effective in controlling undesirable plants in transplanted rice crops. The pyridine herbicide combination according to the present invention is effective against grass weeds (barnyard grass, crabgrass) and Mo.
On the other hand, the N-benzylhaloacetamide component of the combination according to the invention is highly effective in controlling Cyperus and 5cjrpus species, including Carex. The herbicide combination according to the invention thus provides effective, broad-spectrum weed control of unwanted noxious weeds.

In order to demonstrate the control of these undesirable plants, the pyridine compounds according to the present invention and the haloacetamides according to the present invention were tested separately for weed control in a chemical association test area,
At the same time, we also tested the use of combinations of these compounds.

During the following tests, the types of weeds are indicated by the following symbols.

E-Cyperus 5erotinus (embryo)
The herbicide was tested as follows. The variety Nihonbale was planted by mechanical transplantation in an area the size of 4 door 2. Various weeds were mixed with the soil, sown in the case of seed-propagating weeds, and scattered with embryos throughout the area in the case of embryo-propagated weeds.

After transplanting the rice and seeding the areas, each area was treated with a pyridine herbicide according to the invention, a haloacetamide according to the invention, or a combination of both. Use all three districts for each exam, and lower? , Pk is the average of these three areas.

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O) to 6°C to -6°C C > height + 11111111 C 鵠 000000 こ 00 As can be seen from the above data, the mixture according to the invention appears to be relatively safe for transplanted rice and is therefore suitable for rice crops. It can be used for selective control of common fungi.

Herbicidal compositions according to the invention, including concentrates which require dilution prior to application, contain the active ingredient and an adjuvant in liquid or solid form. The compositions can be prepared by forming the active ingredient into a finely divided particulate solid, granule, pellet, solution, dispersion, or emulsion by mixing with all adjuvants such as diluents, extenders, carriers, and conditioning agents. can be prepared,
Alternatively, the two active ingredients may be applied individually as liquids, solids, etc. Thus, the active ingredient may be used in conjunction with all adjuvants such as finely divided congeners, liquids of organic origin, water, wetting agents, dispersing agents, emulsifying agents, or any suitable combinations thereof.

Suitable wetting agents include alkylbenzenes or a/l/
jf-/l/t phthalene sulfonates, sulfated fatty alcohols, amines or acid amides, long chain esters of sodium inthionate, esters of sodium sulfoconomonophosphate, sulfated or sulfonated fatty acid esters,
petroleum sulfonates, sulfonated vegetable oils, ditertiary acetylenic glycols, polyoxyethylene derivatives of alkylphenols (such as octylphenoltononylphenol), and hexitol anhydrides (e.g.
Polyoxyethylene derivatives of monohigher fatty acid esters (sorbitan) are included. Particularly suitable dispersants are methylcellulose, polyvinyl alcohol, sodium lignin sulfonate, polymerizable alkylnaphthalene sulfonates, sodium naphthalene sulfonate, and polymethylene bisnaphthalene sulfonate.

Irrigation agents are water-dispersible compositions containing an active ingredient, an inert solid extender, and one or more wetting and dispersing agents. Inert solid extenders are of mineral origin;
For example, natural clays, diatomaceous earth, and synthetic minerals derived from silica are common. Examples of such extenders include kaolinite, attapulgite clay, and synthetic magnesium silicates. Wettable powder compositions according to the invention typically contain 0.5 to 6 active ingredients.
0 parts or more (preferably 5 to 20 parts), about 0.25 parts of wetting agent
to 25 parts (preferably 1 to 15 parts), about 0.2 parts of dispersant
5 to 25 parts (preferably 1.0 to 15 parts) and 5 to about 95 parts (preferably 5 parts) of inert solid extender.
~50 parts) Total content. All parts herein are parts by weight of the total composition. If desired, about 0.1 to 2.0 parts of the solid inert extender can be replaced with a corrosion inhibitor or antifoam agent or both.

Other formulations include dust concentrates consisting of suitable extenders and 0.1 to 60% by weight of active ingredient; these powders are applied at concentrations within the range of about 0.1 to 10% by weight. Therefore, it can be diluted.

Aqueous suspension systems can be prepared by dispersing the water-insoluble active ingredient in water with a dispersant by high shear agitation to obtain a stable suspension of very finely divided particles. The resulting thick aqueous suspension system is characterized by its extremely small particle size, so that the coating is very uniform when diluted and sprayed. Suitable concentrations for these formulations are about 0.1 to 60 g of active ingredient, preferably 5 to 50 g.

Emulsion systems can be prepared by stirring a non-aqueous solution of the water-insoluble active ingredient and emulsifier with water until homogeneous and then homogenizing to obtain a stable emulsion system of very fine non-aqueous particles. Suitable concentrations for these formulations include about 0.1-60%, preferably 10-50% by weight of active ingredient. This upper limit is determined by the solubility limit of the active ingredient in the solvent and the packing density of the emulsified particles in water.

Emulsifiable concentrates are usually solutions of the active ingredient together with an emulsifier in a water-immiscible or partially water-immiscible solvent. Examples of suitable solvents for the active ingredients according to the invention include dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, hydrocarbons, ethyl, esters, or ketones that are miscible with water. But the other ^1! Liquid concentrates can be formulated by dissolving the active ingredient in a solvent and then diluting to spray strength, for example with kerosene. Concentrated compositions generally contain about 0.1 to 95 parts (preferably 5 to 60 parts) of active ingredient;
Approximately 0.25 to 50 parts of surfactant (preferably 1 to 25 parts
parts), and optionally 4 to 94 parts of solvent. All parts are by weight based on the total weight of emulsifying oil.

Granules are physically stable particulate compositions consisting of an active ingredient distributed or adhered to a basic matrix of inert, finely divided particulate extenders. To aid in the leaching of the active ingredient from the particulate extender, a surfactant, as previously discussed, can be added to the composition. Natural clay, phyllite, illite, and vermiculite are examples of particulate mineral extenders that can be used. Particularly suitable extenders are porous absorbent preformed particles, such as preformed and sieved granular attapulgite or thermally expanded granular vermiculite, and finely ground clays, such as kaolin clay, watery attapulseite or bentonite. It is thread clay.

The granular composition of the present invention comprises from about 0.1 to about 60 parts by weight of active ingredient per 100 parts by weight of clay and from about 0.1 to about 60 parts by weight of active ingredient per 100 parts by weight of clay.
0 to about 5 parts by weight of surfactant per mm part.

The compositions of the invention may also contain other additives, such as fertilizers, other herbicides, other pest control agents, mitigation agents, etc., as adjuvants or in combination with any of the adjuvants mentioned above. Compounds that can be used in combination with the active ingredient of the present invention include, for example, triazines, ureas, dinitroanilines, carbamates, acetamides, acetanilides,
Included are uracils, acetic acid or phenol derivatives, thiol carbamates, triadols, benzoic acids, nitriles, biphenyl ethers, and the like.

Fertilizers that can be used in combination with the active ingredient include, for example, ammonium nitrate, urea, potash fertilizers and superphosphates. Other useful additives include materials for root growth of the plant, such as compost, manure, humus, sand, and the like.

Herbicidal formulations of the type described above are illustrated below with some representative examples.

■ Emulsion weight % A0 Compound of Example 1 1.0 Compound of Example 2 10.0 Phenol
5.64 Monochlorobenzene
76.96100.00 30 Compound of Example 1 1.00 Compound of Example 2 24.00 Phenol 4.75 Monochlorobenzene 63.65100.00 ■, Flow agent]i'1/A0 Compound of Example 1 2.00 Example 2
Compound of 23.00 Methylcellulose 0+6 Silica Aerol
1.5 Sodium lignosulfonate 6.5 Sodium N-methyl-N-oleyl taurate 2.0 Water
67.7100.00 30 Compound of Example 1 6.0 Example 2
Compounds of 42.0 Methylcellulose 0.6 Silica Aerodel
1.5 Sodium lignosulfonate
6.5 Sodium N-methyl-N-oleyl taurate 2.0 Water
47.
7100.00 1. Hydrating agent 1! Amount: A0 Compound i of Example 1.

Compound of Example 2 24.0 Sodium lignosulfonate 6.0 Sodium N-methyl-N-oleyl-taurate 1.0 Amorphous silica (synthetic) 71.0100
．． 00 B, Example 2 (7) Compound 80.00 Calcium Lignosulfonate 2.75 Amorphous Silica (Synthetic) 16.00 100.00 C0 Compound of Example 1 io.

Sodium lignosulfonate 6.0 Sodium N-methyl-N-oleyl-taurate 1.0 Kaolinite clay 86.0100
．． 00 B, Powder Weight % A9 Compound of Example 1 0.1 Compound of Example 2 1.9 Attapulgite 98. .

100.00 30 Compound of Example 1 3.0 Compound of Example 2 57.0 Montmorillonite 40.0100.0D C0 Compound of Example 2 30.0 Ethylene Glycol 1.0 Bentonite 69.0100.00 05 Compound of Example 1 1. 0 Diatoms ± 99.0100.00 ■, Granule ktht% A1 Compound of Example 1 1.0 Compound of Example 2 14.0 too=o.

30 Compound of Example 1 0.5 Example 2
Compound of 29.5 diatomaceous earth (
20/40) 70.0100.00 C0 Compound of Example 1 0.07 Compound of Example 2 0.93 Ethylene Glycol 5.0 Methylene Blue
0 maiden wax stone
96.9100.00 01 Compound of Example 1 0.2 Compound of Example 2 4.8 Phyllorite (20
/40) 95.0ioo, o.

When operating in accordance with the present invention, an effective amount of a compound of the present invention may be applied to the soil containing the seed-1, or fertilized embryos, or added into the soil medium using any convenient method. When applying liquid or granular solid compositions to soil, conventional methods can be used, such as dust spreaders, boom and hand spreaders, and spray dusters. They can also be applied from airplanes as powders or sprays, as these are effective at low application rates.

The exact amount of active ingredient to be used depends on a variety of factors, such as the type of plant and its stage of development, soil type and condition, precipitation, and the particular compound used. The dosage for selective pre-emergence application to soil is usually from about 0.02 to about 3.0 kl of total active ingredients according to the invention. /
hectare, preferably about 0.1 to about 1.5 kg/ha.

In some cases, lower or higher application rates may be required. A person skilled in the art will be able to readily determine from this specification, including the examples given above, the optimum application rate to be applied in a particular case.

The term "soil" is W6bster's New Inte
rnationalDj ctj onary, 2nd
It is used in its broadest sense as defined in the unedited version (1961). The term therefore refers to any material or medium in which plants can grow roots, and includes not only soil but also compost, manure, mud rich in organic matter, humus, loam, silt, bog, clay. It includes everything that supports the growth of plants, such as sand.

Although the invention has been described with particular modifications, the details are not to be considered limiting.

Claims (5)

[Claims] (1) 2-difluoroethyl-4-(2-methylpropyl)-6-(trifluoromethyl)-3,5-pyridinedicarbothioic acid S,S-dimethyl ester and N-(
α,α-dimethylbenzyl)-α-bromo-tert-
A herbicidal composition containing a mixture of butylacetamides. 2. The composition of claim 1, wherein the ratio of pyridine dicarbothioic acid diester to acetamide is from about 0.1:1 to about 0.03:1 by weight. (3) A method for suppressing the growth of undesirable plants in transplanted rice, which comprises applying the composition according to claim 1 to the plant field. (4) About 0.00 pyridine dicarbothioic acid diester
4. The method of claim 3, wherein the acetamide is applied at a rate of from 5 to about 0.28 kg/ha and the acetamide is applied at a rate of from about 0.1 to about 3 kg/ha. (5) In a method for suppressing the growth of undesirable plants in transplanted rice, 2-difluoroethyl-4-(2-methylpropyl)-6-(trifluoromethyl)-3, 5-pyridinedicarbothioic acid S,S
- dimethyl ester from about 0.005 to about 0.2 kg/ha and N-(α,α-dimethylbenzyl-α-
A control method as described above, comprising applying from about 0.1 to about 3 kg/ha of bromo-tert-butylacetamide.