JP2002220389A - Pyridylbenzoxazine derivative, herbicide and its intermediate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel pyridylbenzoxazine derivative which is useful in the fields of chemical industry and agriculture, especially the manufacture of agricultural chemicals, and also provide a herbicide which contains the derivative as an active ingredient. SOLUTION: The pyridylbenzoxazine derivative is represented by formula (1) (wherein R1 is a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a (lower)haloalkyl group, a (lower)alkoxycarbonyl(lower)alkyl group, a cyano(lower)alkyl group, a (lower)alkylcarbonyl group, a (lower) cycloalkylcarbonyl group, a (lower)alkenylcarbonyl group, a (lower) haloalkylcarbonyl group or a (lower)alkylsulfonyl group; R2 is hydrogen atom or a halogen atom; R3 is a halogen atom; and R4 is a halogen atom or a halo(lower)alkyl group) and the herbicide which characteristically contains the derivative is also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to novel pyridylbenzoxazine derivatives, herbicides containing them as active ingredients, and intermediates for synthesizing the same. Therefore, the present invention is useful in the chemical industry as well as in agriculture, especially in the field of agrochemical manufacturing.

[0002]

2. Description of the Related Art Heretofore, the following compounds have been known as compounds belonging to benzoxazine derivatives.

(1) JP-A-61-215381 discloses the following general formula (A)

Embedded image (Wherein, X represents a hydrogen atom, a lower alkyl group, a halogen atom, a trifluoromethyl group, a phenoxy group or a halogen-substituted phenoxy group, n represents 0, 1, 2, or 3, and Y represents an oxygen or sulfur atom. And R ¹ and R
² represents a hydrogen atom or a lower alkyl group, but they are not both hydrogen atoms). It is described that the benzoxazine derivative has herbicidal activity.

(2) JP-A-64-34982 discloses the following general formula (B)

Embedded image (Wherein, X represents a hydrogen atom or a halogen atom, R ²
Represents a hydrogen atom, a methyl group or a trifluoromethyl group, R ¹ represents a hydrogen atom, an alkyl group having 1 to 7 carbon atoms,
Examples thereof include an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, and an acyl group having 2 to 7 carbon atoms. The benzoxazine derivative represented by
It is described as having herbicidal activity.

[0005]

The herbicide has a high herbicidal effect at a low dose and has a wide herbicidal spectrum.
Moreover, it is required to have selective herbicidal activity between useful cultivated plants and weeds. However, even if the above-mentioned known compounds have an insufficient herbicidal effect at a low dose or show a high herbicidal effect, they often cause harm to crops. Therefore, development of a herbicide free from such disadvantages is desired.

[0006] An object of the present invention is to provide a novel pyridylbenzoxazine derivative which can replace these known herbicidal compounds, and to provide a herbicide containing the same.

[0007]

Means for Solving the Problems In order to achieve the above object, the present inventors have synthesized a large number of novel pyridylbenzoxazine derivatives and studied their herbicidal effects. As a result, the novel pyridylbenzoxazine derivative represented by the following general formula (1) exhibits excellent herbicidal activity against weeds of paddy rice and field crops at a low dose without causing harm to crops. I found something.

Therefore, according to the gist of the first invention, the following general formula (1)

Embedded image (Wherein, R ¹ is a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower haloalkyl group, a lower alkoxycarbonyl lower alkyl group, a cyano lower alkyl group, a lower alkylcarbonyl group, a lower cycloalkylcarbonyl group, a lower alkenylcarbonyl group Represents a lower haloalkylcarbonyl group or a lower alkylsulfonyl group,
R ² represents a hydrogen atom or a halogen atom, R ³ represents a halogen atom, and R ⁴ represents a halogen atom or a lower haloalkyl group. The present invention provides a pyridylbenzoxazine derivative represented by the following formula:

A second aspect of the present invention is to provide a herbicide containing a pyridylbenzoxazine derivative represented by the above general formula (1) as an active ingredient.

Further, the gist of the third invention is that 6-pyridine-2 represented by the following general formula (2) which is an advantageous intermediate for synthesizing the compound of the general formula (1).
-Yl-3,4-dihydro-2H-1,4-benzoxazine derivatives.

Embedded image

The “lower alkyl group” used in the definition of the substituent for R ¹ in the general formula (1) includes, for example,
Methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, 2-methylbutyl, neopentyl, n-hexyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 3,3-dimethylbutyl, 1,1-dimethylbutyl, 1,3-dimethylbutyl, 2,3-dimethylbutyl, 1-ethylbutyl, 1-
Carbon number, such as ethyl-2-methyl-propyl, 1-methyl-1-ethylpropyl, 1-methyl-2-ethylpropyl, 2-methyl-1-ethylpropyl or 2-methyl-2-ethylpropyl group It means 1 to 6 linear or branched alkyl groups.

R ¹ and R represented by the general formula (1)
^The “lower haloalkyl group” used in the definition of ⁴ is
For example, trifluoromethyl, chloromethyl, bromomethyl, dichloromethyl, difluoromethyl, trifluoromethyl, 2-chloroethyl, 2-bromoethyl, 1,1
One or more halogen atoms, such as chlorine, bromine, fluorine, iodine, such as difluoroethyl, 2,2,2-trifluoroethyl, 3-chloropropyl or 3-iodopropyl groups bonded as substituents Shows a lower alkyl group.

The “lower alkenyl group” used in the definition of R ^{1 in} the above general formula (1) includes, for example, vinyl, 1-propenyl, 2-propenyl, 1-methyl-2
-Propenyl, 2-methyl-2-propenyl, 2-ethyl-2-propenyl, 2-butenyl, 1-methyl-2-
Butenyl, 2-methyl-2-butenyl, 1-ethyl-2
A linear or branched alkenyl group having 2 to 6 carbon atoms, such as butenyl, 3-butenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 2-hexenyl, 3-hexenyl or 4-hexenyl Means

The “lower alkynyl group” used in the definition of R ¹ shown in the general formula (1) is, for example, 2-
Propynyl, 1-methyl-2-propynyl, 2-butynyl, 1-methyl-2-butynyl, 1-ethyl-2-butynyl, 3-butynyl, 2-methyl-3-butynyl, 2-
It means a linear or branched alkynyl group having 3 to 6 carbon atoms, such as pentynyl, 4-pentynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl or 5-hexynyl group.

The term "lower alkoxycarbonyl lower alkyl group" used in the definition of R ^{1 in} the formula (1) includes, for example, methoxycarbonylmethyl, ethoxycarbonylmethyl, propoxycarbonylmethyl, isopropoxycarbonylmethyl Group, butoxycarbonylmethyl group, isobutoxycarbonylmethyl group, t
-Butoxycarbonylmethyl group, amyloxycarbonylmethyl group, isoamyloxycarbonylmethyl group, t
-Amyloxycarbonylmethyl group, 1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group, 1
-Propoxycarbonylethyl group, 1-isopropoxycarbonylethyl group, 1-butoxycarbonylethyl group, 1-isobutoxycarbonylethyl group, 1-t-butoxycarbonylethyl group, 1-amyloxycarbonylethyl group or 1-isoamyloxy And a carbonylethyl group.

The “cyano lower alkyl group” used in the definition of R ^{1 in} the general formula (1) includes, for example,
Cyanomethyl, 1-cyanoethyl, 2-cyanoethyl,
1-cyanopropyl, 2-cyanopropyl, 3-cyanopropyl, 1-cyano-2-propyl, 2-cyano-2
-Propyl, 1-cyanobutyl, 2-cyanobutyl, 3
-Cyanobutyl, 4-cyanobutyl, 1-cyano-2-
Butyl, 2-cyano-2-butyl, 1-cyano-3-butyl, 2-cyano-3-butyl, 1-cyano-2-methyl-3-propyl, 2-cyano-2-methyl-3-propyl, 3-cyano-2-methyl-3-propyl or 2
-Cyanomethyl-2-propyl group and the like.

[0017] The A used in the definition of R ¹ "lower alkyl group" represented by the general formula (1), for example, methylcarbonyl group, ethylcarbonyl group, an isopropyl group, n- butyl group, t- butyl Carbonyl group, n-pentylcarbonyl group, neopentylcarbonyl group or n-hexylcarbonyl group,
And so on.

The “lower cycloalkylcarbonyl group” used in the definition of R ^{1 in} the above general formula (1) includes, for example, a cyclopropylcarbonyl group, a cyclopentylcarbonyl group or a cyclohexylcarbonyl group,
And so on.

[0019] The A used in the definition of R ¹ "lower alkenyl group" represented by the general formula (1), for example, vinyl group, 1-propenyl group, 2-propenyl group, 1-methyl-1 -Propenylcarbonyl group, 2-methyl-1-propenylcarbonyl group, 2-butenylcarbonyl group, 3-butenylcarbonyl group, 1-pentenylcarbonyl group, 2-pentenylcarbonyl group, 1-hexenylcarbonyl group or 2-hexenyl A carbonyl group, and the like.

The “lower haloalkylcarbonyl group” used in the definition of R ¹ shown in the general formula (1) is
For example, it means a chloromethylcarbonyl group, a fluoromethylcarbonyl group, a trifluoromethylcarbonyl group, a dichloromethylcarbonyl group, a 1-chloroethylcarbonyl group, a 2-chloroethylcarbonyl group or a pentafluoropropylcarbonyl group.

[0021] The term "lower alkylsulfonyl group" used in the definition of R ¹ represented by the general formula (1), for example, methylsulfonyl, ethylsulfonyl, n- propylsulfonyl, 1-methyl-ethylsulfonyl, n- butylsulfonyl , 1-methylpropylsulfonyl, 2-methylpropylsulfonyl or 1,1-dimethylethylsulfonyl group.

The “halogen atom” used in the definition of R ² , R ³ and R ^{4 in} the general formula (1) is
It means chlorine atom, bromine atom, iodine atom or fluorine atom.

Next, as examples of the pyridylbenzoxazine derivatives of the general formula (1) according to the first present invention, the compounds listed in Examples 1 to 10 and the compounds listed in Tables 5 and 6 described below are included. And specific examples shown in Tables 1 and 2 below.

[0024]

[Table 1]

[0025]

[Table 2]

Next, a method for producing the pyridylbenzoxazine derivative of the general formula (1) according to the first invention will be described.

In general, the compound of the general formula (1) is a novel compound 6-pyridine-
It can be produced by a method comprising a condensation reaction of a 2-yl-3,4-dihydro-2H-1,4-benzoxazine derivative with a halide represented by the following general formula (3) (reaction formula 1).

[0028]

Embedded image

However, in the above reaction formula 1,
R ¹ , R ² , R ³ and R ⁴ have the same meaning as described above.

The condensation reaction in this step is carried out in a suitable organic solvent or without solvent in the presence of 6-pyridin-2-yl-3,4-dihydro-2H-1,4-benzine represented by the general formula (2). This is achieved by mixing a halide represented by the general formula (3) with an oxazine derivative together with a dehydrohalogenating agent.

Examples of the solvent used in the reaction include aromatic hydrocarbons such as benzene, toluene and xylene, aliphatic alcohols such as methyl alcohol, ethyl alcohol and tert-butyl alcohol, acetonitrile and propionitrile. Such as nitriles, ethyl acetate, esters such as ethyl propionate, diethyl ether, ethers such as tetrahydrofuran, acetone, ketones such as methyl ethyl ketone;
Amides such as N, N-dimethylformamide and N, N-dimethylacetamide, pyridine, and the like, or a mixed solvent thereof can also be used. The solvent for the reaction is preferably N, N-dimethylformamide, toluene.

Examples of the dehydrohalogenating agent used in the reaction include organic tertiary amines such as triethylamine, tributylamine, diethylisopropylamine, 4-dimethylaminopyridine, pyridine and the like, or sodium methoxide, sodium ethoxide, potassium Alkali metal alkoxides such as tertiary butoxide or alkali metal carbonates such as sodium carbonate and potassium carbonate, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, sodium hydride and potassium hydride Such alkali metal hydrides can be mentioned, but preferably, sodium hydride,
Triethylamine. The amount of the above base is 1 to 4 equivalents, preferably 1 to 2 equivalents, based on the starting material.

The reaction temperature is usually from -10 to 150 ° C, and the preferred reaction temperature is from 0 to 100 ° C. The reaction time varies depending on the reaction temperature and the reaction substrate, but is usually 30 minutes to
Complete in 24 hours.

The compound of the general formula (1), which is the desired reaction product produced by this reaction, is collected from the obtained reaction solution by a usual post-treatment. For example, an extraction solvent such as toluene and ethyl acetate and water are added to the reaction mixture, washed with water,
It is obtained by distilling off the solvent. The obtained target product can be purified, if necessary, by an operation such as column chromatography or recrystallization.

Examples of the preparation of the compound of the present invention of the general formula (1) according to the above reaction formula 1 are shown in Examples 1 to 3 below.

The halides represented by the general formula (3) used in the above reaction are known ones, and can be obtained as reagents or can be easily synthesized according to known methods.

The compound represented by the general formula (2), which is a starting material used in the reaction represented by the above reaction formula 1, is a novel compound, and is a known compound as shown in the following reaction formula 2. It can be synthesized according to the method.

[0038]

Embedded image (R ² , R ³ and R ⁴ represent the same meaning as described above.)

6- of the novel compound represented by the general formula (2)
Pyridin-2-yl-3,4-dihydro-2H-1,4
-Specific examples of the benzoxazine derivative are listed in Table 3, but the present invention is not limited thereto.

[0040]

[Table 3]

First, the compound represented by the above general formula (4) is reacted with chloroacetyl chloride in dioxane in the presence of sodium hydrogen carbonate. In this reaction, generally 1.0 mol per mol of the compound represented by the general formula (4) is used.
To 1.5 moles, preferably 1.0 to 1.2 moles of chloroacetyl chloride and 1.0 to 3.0 moles, preferably 1.0 to 2.0 moles of sodium hydrogen carbonate. The reaction is usually performed at a reaction temperature of -10C to 30C, and a preferred reaction temperature is -5C to 20C. The reaction time varies depending on the reaction substrate and the reaction temperature, but is usually 10 minutes.
Complete in minutes to 2 hours. Next, an aqueous solution of sodium hydrogen carbonate is added to the obtained reaction mixture, and the mixture is heated to close the ring, thereby obtaining a compound represented by the general formula (5).
The amount of sodium bicarbonate used here is generally from 1.0 mol to 4.0 mol, preferably from 2.0 mol to 3.0 mol. The reaction is usually performed at a reaction temperature of 40 ° C to 100 ° C, and a preferred reaction temperature is 50 ° C to 70 ° C.
The reaction time varies depending on the reaction substrate and the reaction temperature, but is usually completed in 30 minutes to 12 hours. The compound represented by the general formula (5), which is a reaction product generated in this step, is collected from the obtained reaction solution by usual post-treatment. For example, dioxane is distilled off from the reaction mixture and water is added, whereby crude crystals of the compound represented by the general formula (5) precipitate. Then, after thoroughly washing the crude crystals with water, they are sufficiently dried. The product obtained is used in the next step without further purification.

In the next step, the compound represented by the general formula (5) obtained in the previous step is reduced with sodium borohydride in dioxane in the presence of acetic acid to obtain the desired compound of general formula (5). The compound represented by the formula (2) can be produced. In this reaction, 1.0 to 5.0 mol, preferably 2.0 to 4.0 mol of sodium borohydride and 1.0 to 5.0 mol are generally used per 1 mol of the compound represented by the general formula (5). 0 mol, preferably 2.0 to 4.0
Use molar acetic acid. The reaction is usually performed at a reaction temperature of -10 ° C to 90 ° C, and a preferable reaction temperature is 0 ° C to 70 ° C.
It is. The reaction time varies depending on the reaction substrate and the reaction temperature, but is usually completed in 30 minutes to 12 hours. The compound represented by the general formula (2), which is a reaction product generated in this step, is collected from the obtained reaction mixture by usual post-treatment. For example, water can be added to the reaction mixture, and extraction and isolation can be performed using an extraction solvent such as toluene or ethyl acetate. The obtained product (2) can be purified by an operation such as column chromatography or recrystallization, if necessary.

The compound represented by the general formula (4) can be synthesized according to a known method, for example, a method described in Japanese Patent Application Laid-Open No. 9-503748.

The production of the compound represented by the general formula (2) is shown in Example 4 below.

Further, the herbicide according to the second aspect of the present invention will be specifically described. The pyridylbenzoxazine derivative represented by the general formula (1) according to the present invention has excellent herbicidal activity as shown in the test examples described below, and can be used as a herbicide for controlling weeds. Since the compound of the present invention exhibits selective herbicidal activity between the following weeds and crops, it can be used as a selective herbicide.

[0048] As the weeds of the family Gramineae, there are Alopecurus and Oats (Aven).
a), Barley (Bromus), Cyperacea (Cy)
perus), crabgrass (Digitaria), barnyardgrass (Echinochloa), kuroguwai (Eleoc)
haris), Eleusine (Eleusine), Monochoria (Monochoria), Panax (Panic)
um), Spruce (Paspalum), Pleurotus (Phleum), Poa annua (Po)
a), Omodaka (Sagittaria), Firefly (Sirpus), Enokorogosa (Setari)
a), Johnson Glass (Sorghum) and the like.

As broadleaf weeds, strawberry (Abutil)
on), Amaranthus, Ragweed (Ambrosia), Kosendangsa (Biden)
s), Chenopodium, Galium, Ipomoea, Lindenia, Persica
ria), purslane (Portulaca), stag beetle (Rotala), chickweed (Stellari)
a), Violet (Viola), Onamomi (Xanthi)
um).

Useful cultivated plants of the genus Grass in a field to which the herbicide of the present invention can be applied, ie, crops include barley (Hordeum), rice (Oryza), sugarcane (Saccharum), and wheat (Triticu).
m), corn (Zea) and the like.

Also, as a broad leaf crop, peanuts (A
rachis), sugar beet (Beta), oilseed rape
(Brassica), soybean (Glycine), cotton (Gossypium), tomato (Lycopers)
icon).

The use of the herbicide of the present invention is not limited to the weeds and crops exemplified above.

In the herbicide according to the second aspect of the present invention, the pyridylbenzoxazine derivative of the general formula (1) according to the first aspect of the present invention is used as an active ingredient, and is formulated together with a carrier and other auxiliaries.

That is, when formulated as a herbicide, the compound of the general formula (1) is mixed with at least one of a carrier or diluent, an additive, an auxiliary and the like by a known method, and is usually used as a pesticide. The formulation used, for example,
Granules, wettable powders, wettable powders for granules, emulsions, flowables, tablets, powders, microcapsules, jumbo and the like can be prepared as appropriate forms.

Other pesticides such as fungicides, insecticides,
It can be mixed or used in combination with a herbicide, acaricide, a safener (safener), a plant growth regulator, a fertilizer, a soil conditioner, and the like. In particular, by mixing and using other herbicides, not only can the amount of used drug be reduced and labor saving be achieved, but also the broadening of the herbicidal spectrum by the synergistic action of both drugs and the stronger effect by the synergistic action Can also be expected. At this time, a plurality of known herbicides and safeners can be simultaneously combined and compounded.

As the carrier used in the above-mentioned preparation, any solid or liquid carrier can be used as long as it is generally used for agricultural chemicals. The carrier is not limited to a specific one.

For example, these solid carriers include mineral powders (kaolin, bentonite, clay, montmorillonite, talc, diatomaceous earth, mica, vermiculite, quartz, calcium carbonate, apatite, white carbon, slaked lime, silica sand, ammonium sulfate, urea ), Vegetable powders (soybean flour,
Flour, wood flour, tobacco flour, starch, crystalline cellulose, etc.), high molecular compounds (petroleum resin, polyvinyl chloride, ketone resin, etc.), alumina, silicates, sugar polymers, highly dispersible silicic acid, waxes, etc. Is mentioned.

Examples of the liquid carrier that can be used include water and alcohols (methyl alcohol, ethyl alcohol, n
-Propyl alcohol, isopropyl alcohol, butanol, ethylene glycol, benzyl alcohol, etc.), aromatic hydrocarbons (toluene, benzene, xylene, ethylbenzene, methyl naphthalene, etc.), ethers (ethyl ether, ethylene oxide, dioxane, tetrahydrofuran, etc.), Ketones (acetone,
Methyl ethyl ketone, cyclohexanone, methyl isobutyl ketone, isophorone, etc., esters (ethyl acetate, butyl acetate, ethylene glycol acetate, amyl acetate, etc.), acid amides (dimethylformamide, dimethylacetamide, etc.), nitriles (acetonitrile, propionitrile) , Acrylonitrile, etc.), sulfoxides (such as dimethyl sulfoxide), alcohol ethers (ethylene glycol monomethyl ether,
Aliphatic or alicyclic hydrocarbons (eg, n-hexane, cyclohexane), industrial gasoline (eg, petroleum ether, solvent naphtha), petroleum fractions (eg, paraffins, kerosene, gas oil), And the like.

When formulated into emulsions, wettable powders, flowables and the like, various surfactants of the present invention are used for the purpose of emulsification, dispersion, solubilization, wetting, foaming, lubrication, spreading and the like. It is included in herbicides. Such surfactants include nonionic surfactants (polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan alkyl ester, etc.),
Anionic surfactants (alkylbenzene sulfonate, alkyl sulfosuccinate, alkyl sulfate, polyoxyethylene alkylalkyl sulfate, aryl sulfonate, etc.), cationic surfactants (alkyl amines (laurylamine, stearyltrimethylammonium chloride, etc.) , Polyoxyethylene alkylamines] and amphoteric surfactants [carboxylic acid (betaine type), sulfate salt, etc.] and the like, but are not limited only to those exemplified.

In addition to these, polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC),
Various adjuvants such as gum arabic, polyvinyl acetate, sodium alginate, gelatin, tragacanth gum and the like can be used.

In the second herbicide of the present invention, the compound of the present invention represented by the general formula (1) is used in an amount of 0.001% to 95% (% by weight; hereinafter the same) when the above-mentioned various preparations are produced.
Preferably, it can be formulated so as to contain in a range of 0.01% to 75%. For example, usually 0.01% to 10% for granules, jumbo and tablets, 1 to 75% for wettable powders, flowables, wettable granules, emulsions or microcapsules, 0.01% for dust
It can be contained in the range of ５5%.

In the case of granules, tablets, jumbo preparations, microcapsules, powders and flowables, the preparations thus prepared can be used as they are on the soil surface, in the soil or in water, in an amount equivalent to 10%. 2 per are
g in the range of about 300 g. In the case of a water-dispersible powder, a water-dispersible granule, an emulsion or the like, it may be diluted with water or a suitable solvent, and the obtained diluted chemical solution may be sprayed as an active ingredient in a range of about 2 g to 300 g per 10 ares.

[0061]

BEST MODE FOR CARRYING OUT THE INVENTION The production examples of the compound of the general formula (1) and the compound of the general formula (2) [intermediate of the synthesis of the general formula (1)] according to the present invention will be described below with reference to examples of the present invention. Will be further described, but the present invention is not limited to these examples.

[0062]

EXAMPLES Example 1 6- (3-chloro-5-trifluoromethyl-pyridin-2-yl) -4-propargyl-3,4-dihydro-
2H-1,4-benzoxazine (Compound No.
Production of 17) In a 100 ml four-necked flask equipped with a stirrer, a reflux condenser and a thermometer capable of measuring from 0 to 100 ° C,
3.2 g (10 mmol) of 6- (3-chloro-5-trifluoromethyl-pyridin-2-yl) -3,4-dihydro-2H-1,4-benzoxazine and N, N-
40 ml of dimethylformamide was added thereto, and the mixture was mixed with 60 ml of sodium hydride at 5 ° C. while cooling with an ice water bath while stirring well.
0.8 g (20 mmol) of a 20% oily suspension was added. After 30 minutes, 2.4 g (20 mmol) of propargyl bromide was added at 5 ° C under cooling with an ice-water bath, the ice-water bath was removed, the mixture was stirred at room temperature for 30 minutes, and heated to 80 ° C and stirred for 4 hours. After cooling to room temperature, the obtained reaction mixture was poured into ice water and transferred to a 300-ml separatory funnel.
50 ml was added for extraction. The ethyl acetate layer was further washed twice with water, and dried with 50 g of anhydrous sodium sulfate. The sodium sulfate used for this drying was filtered under reduced pressure using an aspirator using a Nutsche type 6-cm diameter product name “Kiriyama funnel”, and the filtrate was concentrated under reduced pressure using an aspirator. Then, the residue is purified by silica gel chromatography using silica gel (trade name: silica gel 60H) using toluene as a developing solvent to obtain 6- (3-chloro-5-trifluoromethyl) as the title compound. -Pyridin-2-yl) -4-propargyl-
2.5 g of 3,4-dihydro-2H-1,4-benzoxazine was obtained (yield 72%, viscous oil).

Example 2 6- (3-Chloro-5-trifluoromethyl-pyridin-2-yl) -4- (1-ethoxycarbonylethyl)
Production of -3,4-dihydro-2H-1,4-benzoxazine (Compound No. 33 in Table 1) 100 ml four-necked equipped with a stirrer, a reflux condenser and a thermometer capable of measuring from 0 to 100 ° C. In the flask,
3.2 g (10 mmol) of 6- (3-chloro-5-trifluoromethyl-pyridin-2-yl) -3,4-dihydro-2H-1,4-benzoxazine and N, N-
40 ml of dimethylformamide was added thereto, and the mixture was mixed with 60 ml of sodium hydride at 5 ° C. while cooling with an ice water bath while stirring well.
0.8 g (20 mmol) of a 20% oily suspension was added. After 30 minutes, 3.6 g of ethyl 2-bromopropionate
(20 mmol) was added. Then, the ice water bath was removed, and the mixture was stirred at room temperature for 30 minutes, heated to 90 ° C., and stirred for 6 hours.
After cooling to room temperature, the obtained reaction mixture was poured into ice water,
Transfer to a 300 ml separatory funnel and add 150 ml of ethyl acetate.
ml was added for extraction. The ethyl acetate layer was further washed twice with water, and dried with 50 g of anhydrous sodium sulfate. The sodium sulfate used for this drying was filtered under reduced pressure using an aspirator using a Nutsche type 6-cm diameter product name “Kiriyama funnel”, and the filtrate was concentrated under reduced pressure using an aspirator. Then, the residue is purified by silica gel chromatography using silica gel (trade name: silica gel 60H) using toluene as a developing solvent to obtain 6- (3-chloro-5-trifluoromethyl) as the title compound. -Pyridin-2-yl) -4- (1-ethoxycarbonylethyl) -3,4-dihydro-2H-1,4-benzoxazine 2.7 g (yield 65%, viscous oil).

Example 3 6- (3-Chloro-5-trifluoromethyl-pyridin-2-yl) -4-methylsulfonyl-3,4-dihydro-2H-1,4-benzoxazine (compound of Table 1) N
o. Production of 56) In a 100 ml four-necked flask equipped with a stirrer, a reflux condenser and a thermometer capable of measuring from 0 to 100 ° C,
6- (3-chloro-5-trifluoromethyl-pyridin-2-yl) -3,4-dihydro-2H-1,4-benzoxazine 3.2 g (10 mmol), toluene 50
ml and triethylamine 2.0 g (20 mmol)
And stirred well, and 2.3 g (20 mmol) of methanesulfonyl chloride was added thereto. Then, the reaction mixture was heated to 80 ° C. and stirred for 2 hours. After cooling the obtained reaction mixture, it was transferred to a 200-ml separating funnel, and washed by adding 50 ml of water. Then, the toluene layer was further washed once with water and dried with 20 g of anhydrous sodium sulfate. The sodium sulfate used for drying was filtered under reduced pressure using an aspirator using a Nutsche type 4 cm diameter trade name “Kiriyama funnel”, and the filtrate was concentrated under reduced pressure using an aspirator. The residue is purified by using toluene as a developing solvent and silica gel (Merck company name: silica gel 60H).
And purified by silica gel chromatography using, to give the title compound 6- (3-chloro-5-trifluoromethyl-pyridin-2-yl) -4-methylsulfonyl-3,4-dihydro-2H-. 2.7 g of 1,4-benzoxazine were obtained (yield 70%, melting point: 144).
146 ° C).

Further, a production example of the starting compound used in Examples 1 to 3 of the general formula (2) is shown in Example 4 below.

Example 4 Production of 6- (3-chloro-5-trifluoromethyl-pyridin-2-yl) -3,4-dihydro-2H-1,4-benzoxazine (No. 3 in Table 3) Compound) In a 2000 ml four-necked flask equipped with a stirrer, a reflux condenser and a thermometer capable of measuring up to 100 ° C.,
Amino-4- (3-chloro-5-trifluoromethyl-
28.9 g of pyridine-2-yl) phenol (0.1 m
ol) was dissolved in 500 ml of dioxane, and 33.6 g (0.4 mol) of sodium hydrogen carbonate was added thereto with stirring. Then, there was added 13.6 g of chloroacetyl chloride (0.
12 mol) was added dropwise over 40 minutes. After the addition, the mixture was stirred at room temperature for 1 hour. Then, the reaction mixture is mixed with 50 pieces of water.
After adding 0 ml, the mixture was heated to 60 ° C. and stirred for 6 hours. After completion of the reaction, dioxane was distilled off from the reaction mixture under reduced pressure using an aspirator, and 700 ml of water was added to precipitate crystals. The crystals were collected by filtration using a nutsche and washed well with water. Then, it was sufficiently dried and 6- (3-chloro-5-
Trifluoromethyl-pyridin-2-yl) -3,4-
30.3 g of dihydro-2H-1,4-benzoxazin-3-one was obtained. 2000 m equipped with a stirrer, a reflux condenser and a thermometer capable of measuring up to 100 ° C.
In a four-necked flask of l, 6- (3-chloro-5-trifluoromethyl-pyridin-2-yl)-obtained above
3,4-dihydro-2H-1,4-benzoxazine-
Dissolve 30.3 g of 3-one in 600 ml of dioxane,
Sodium borohydride 13.9 at 5 ° C under ice water bath cooling
g (0.368 mol) was added. Then, under cooling with an ice water bath, 22 g (0.368 mol) of acetic acid was slowly added dropwise thereto. Then, the reaction mixture is heated to 60 ° C.
Stirred for hours. After completion of the reaction, the reaction mixture was cooled to room temperature, the reaction mixture was poured into ice water, transferred to a 2,000-ml separatory funnel, and extracted with 700 ml of toluene. Then, the organic layer was washed twice with water and dried with 200 g of anhydrous sodium sulfate. The sodium sulfate used for the drying was filtered under reduced pressure using an aspirator using a Nutsche type 9.5 cm diameter product name “Kiriyama funnel”, and the filtrate was concentrated under reduced pressure using an aspirator. Then, the residue is used as a developing solvent in a toluene-acetone mixture (solvent volume ratio: toluene: acetone = 3).
5: 1) and purified by silica gel chromatography using silica gel (trade name: silica gel 60H, Merck Ltd.) to give the title compound, 6- (3-chloro-).
5-trifluoromethyl-pyridin-2-yl) -3,
4-dihydro-2H-1,4-benzoxazine20.
8 g was obtained (yield 72%, melting point: 92-94 ° C).

Further, the method for preparing a herbicide according to the second aspect of the present invention will be described specifically with reference to Examples 5 to 10 below. However, the second present invention is not limited to these Examples 5 to 10, but may be mixed with other various additives at an arbitrary ratio to form a formulation.

Compound No. Are shown in Tables 1 and 2 above, and "parts" in Examples all mean parts by weight.

Example 5 (Granules) Compound No. 17 parts of compound, 1 part of calcium ligninsulfonate, 1 part of lauryl sulfate,
Water 15 in 30 parts of bentonite and 67 parts of talc
The resulting mixture was kneaded with a kneader and granulated with an extrusion granulator. This is dried with a fluidized drier to obtain granules containing 1% of the active ingredient.

Example 6 (Floable agent) 1. 20.0 parts of compound 33, sodium salt of di-2-ethylhexyl sulfosuccinate
0 parts, polyoxyethylene nonyl phenyl ether
2.0 parts, 5.0 parts of propylene glycol, 0.5 part of an antifoaming agent and 70.5 parts of water are uniformly mixed and pulverized by a wet ball mill to obtain a flowable agent containing 20% of the active ingredient.

Example 7 (Dry flowable agent) 75 parts of 36 compound, 5 parts of sodium alkylnaphthalenesulfonate, 5 parts of polyoxyethylene styrylphenyl ether sulfate, 5 parts of white carbon and 10 parts of clay are uniformly mixed, pulverized and dry-flowable (granular hydration). ) Get the agent.

Example 8 (Wettable powder) 15 parts of 45 compounds, 15 parts of white carbon, 3 parts of calcium ligninsulfonate,
2 parts of polyoxyethylene nonylphenyl ether, 5 parts of diatomaceous earth and 60 parts of clay are uniformly mixed by a pulverizer to obtain a wettable powder containing 15% of active ingredient.

Example 9 (Emulsion) 20 parts of 56 compound, 14 parts of polyoxyethylene styryl phenyl ether, 6 parts of calcium dodecylbenzenesulfonate and 60 parts of xylene are mixed to obtain an emulsion containing 20% of the active ingredient.

Example 10 (Powder) Compound No. Dust containing 0.5% of active ingredient by uniformly mixing and pulverizing 0.5 part of 49 compound, 0.5 part of white carbon, 0.5 part of calcium stearate, 50.0 parts of clay and 48.5 parts of talc Get.

According to the above-mentioned preparation examples, the herbicides using the compound of the general formula (1) according to the present invention can be prepared as herbicides in various dosage forms.

Next, Test Examples 1 and 2 are shown to illustrate the herbicidal effect of the compound of the general formula (1) according to the present invention.

Test Example 1 Herbicidal effect test on paddy field weeds and phytotoxicity test on transplanted paddy rice Paddy field soil was filled into a 1 / 5,000 areal Wagner pot, water was added thereto, and a fertilizer (N: P: K = 17) : 1
7:17) was mixed, and the water was removed. After that, 30 seeds of each of the seeds of the foxtail, broadleaf weeds (Azena, Konagi, Kikasigusa) and firefly were sown at a depth of 1 to 2 cm. Immersed immediately after sowing, the water depth was maintained at about 2 cm. Subsequent management was performed in a glass greenhouse. Two days after sowing, two-leaf stage rice was transplanted, and one day after transplanting the rice, Example 8 was used.
The wettable powder prepared according to the above was diluted with water, and a predetermined amount of the water-diluted drug solution was dropped on the water surface.

This test was carried out twice in one chemical concentration section. Twenty-one days after the chemical treatment, the herbicidal rate (%) was determined by the following formula, and the herbicidal effect and the phytotoxicity were investigated based on the following evaluation indexes. .

[0079]

(Equation 1)

[0080]

[Table 4]

[0081]

[Table 5]

The results are as shown in Table 5.

Compound No. Are shown in Tables 1 and 2 above.

Test Example 2 Test of herbicidal effect on upland weeds and phytotoxicity test 1) Test of herbicidal effect on upland weeds Field soil (alluvial loam) was placed in a 1/5000 areal pottery pot, and Mehishiba, Enokorogusa, Ichibi, Fifty seeds of each of the weeds, i.e., oakweed and oakweed, were uniformly sowed, covered with 0.5 cm of soil, and the surface layer was lightly pressed.
Two days after sowing, the emulsion prepared according to Example 9 was diluted with water, and the diluted water solution was sprayed on the soil surface at a rate of 100 liters per 10 ares. When the application rate of the active ingredient is converted, it corresponds to 30 g per 10 ares. 30 days after the chemical treatment, the herbicidal effect was evaluated based on the same criteria as in Test Example 1.

2) Chemical Injury Test on Crops Field soil (alluvial loam) was filled in a 1 / 10,000 areal unglazed pot, and the seeds (5 soybeans, 5 corns, 5 sugar beets, 10 sugar beets) of each crop 10 grains, 5 cottons, 10 wheats and 10 barleys) were sown in separate pots, and the surface layer was lightly pressed. One day after sowing, the emulsion prepared according to Example 8 was diluted with water, and the diluted water solution was sprayed on the soil surface at a rate of 100 liters per 10 ares. The active ingredient application rate is 1
This is equivalent to 30 g per 0 ares. Thirty days after the chemical treatment, the degree of phytotoxicity on each crop was investigated based on the same criteria as in Test Example 1. Table 6 shows the results. In addition,
Compound No. Are shown in Tables 1 and 2 above.

[0086]

[Table 6]

[0087]

Industrial Applicability The novel herbicidal pyridylbenzoxazine derivative of the general formula (1) according to the present invention can control various weeds in paddy fields and fields at a low dose and has excellent selectivity to crops. Therefore, the novel compounds of the general formula (1) according to the present invention are useful as herbicides. Further, the compound of the general formula (2) is useful as a herbicide in the general formula (1)
Useful as an intermediate (raw material) for synthesizing the compound of

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takashi Takeuchi 2-chome, 3-chome, 3-chome, Iriya 3-chome, Zama City, Kanagawa Prefecture 4C063 AA01 BB01 CC54 DD12 EE03 4H011 AB01 AB02 BA01 BB10 BC03 BC06 BC07 BC18 BC19 BC20 DA02 DA15 DA16 DC05 DC06 DD01 DH03

Claims (3)

[Claims] 1. A compound of the general formula (1) (Wherein R ¹ is a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower haloalkyl group, a lower alkoxycarbonyl lower alkyl group, a cyano lower alkyl group, a lower alkylcarbonyl group, a lower cycloalkylcarbonyl group, a lower alkenylcarbonyl group A lower haloalkylcarbonyl group or a lower alkylsulfonyl group, R ² represents a hydrogen atom or a halogen atom, R ³ represents a halogen atom, and R ⁴ represents a halogen atom or a lower haloalkyl group.) Benzoxazine derivatives. 2. A herbicide comprising the pyridylbenzoxazine derivative of the general formula (1) according to claim 1 as an active ingredient. 3. A compound of the general formula (2) (Wherein R ² represents a hydrogen atom or a halogen atom;
³ represents a halogen atom, and R ⁴ represents a halogen atom or a lower haloalkyl group. 6) -Pyridin-2-yl-3,4-dihydro-2H-1,4-benzoxazine derivative represented by the formula: