JPH07285964A - 1,3-oxazin-4-one derivative and herbicide containing the same - Google Patents

Abstract

PURPOSE:To obtain a new derivative capable of providing a selective herbicide not damaging rice, having herbicidal spectrum in a wide range at a low dose, capable of using over wide period before or after occurrence of weeds and free from the change of effect, phytotoxicity, etc. even by leakage, etc., of water. CONSTITUTION:6-Methyl-3-[1-methyl-1-(benzothiazol-2-yl)ethyl]-5-(subst ituted phenyl)-2,3-dihydro-4H-1,3-oxazin-4-one derivative of formula I (X is H or F). The derivative is obtained by reacting a 2,2-dimethyl-1,3-dioxin-4-one derivative of formula II with a compound of formula III in an inert solvent such as toluene at 20-160 deg.C (or boiling point of the solvent normally for 1-150min. Furthermore, a ratio of the compound of formula III to the compound of formula II is preferably 0.6-2 equivalent (especially 0.9-1.1 equivalent).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is a novel 6-methyl-3-
[1-Methyl-1- (benzothiazol-2-yl) ethyl] -5- (substituted phenyl) -2,3-dihydro-4
The present invention relates to H-1,3-oxazin-4-one derivatives and herbicides containing these as active ingredients.

[0002]

2. Description of the Related Art 1,3 having herbicidal activity so far
Several oxazin-4-one derivatives have been disclosed. For example, WO-93 / 15064 describes the following general formula (Formula 3)

[0003]

[Chemical 3] A compound represented by the formula (R ₃ represents an alkyl group, an optionally substituted aralkyl group, or an optionally substituted aryl group) is disclosed as a herbicide, but contains a hetero atom as the aryl group. No compound disclosed.

The oxazine compounds disclosed in WO-93 / 15064 have extremely high activity when used in paddy fields and exhibit a broad herbicidal spectrum. However, if there is some kind of external factor, for example, downward movement of water due to water leakage or the like, it causes significant phytotoxicity to paddy rice, which makes it difficult to use in actual fields.

[0005]

In recent years, there has been a strong demand for a highly selective herbicide that does not harm crops and kills only weeds. Further, in paddy fields, effective herbicides that can reliably control difficult-to-control weeds such as millet, firefly, eel, and cypress are desired. Furthermore, there is a strong demand for the development of a herbicide which can be used for any period from the time of emergence of weeds to the growing season and has a long-lasting effect.

Under such a situation, there is a problem in the actual paddy field that there are various external factors that affect the effects of herbicides, phytotoxicity and the like. For example, the external factors are soil quality of paddy fields, weather conditions such as temperature and light, inundation depth, water leakage, water movement due to inflow and outflow, and sometimes differences in rice planting depth. Are singly or intricately intertwined,
The effect of a drug on weeds, phytotoxicity on crops, or stability of the effect greatly varies. One of the most important of these variables is the effect of water leakage. In many leaky fields, water,
In addition, the use of herbicides must be significantly restricted due to the occurrence of phytotoxicity due to the downward movement of the drug or the fluctuation of the effect.

Therefore, the present invention does not harm rice in paddy fields, has a wide spectrum of weeding with a low dose, and can be used for a wide period from before the emergence of weeds to the growing season after emergence, Another object of the present invention is to provide a selective herbicide that does not show changes in effects and phytotoxicity due to external factors such as water leakage.

[0008]

Means and Actions for Solving the Problems In order to solve the above problems, the present inventors have conducted research on 1,3-oxazin-4-one derivatives, and as a result, the aforementioned WO-93 /
6-Methyl-3- [1 not disclosed in 15064
-Methyl-1- (benzothiazol-2-yl) ethyl] -5- (substituted phenyl) -2,3-dihydro-4H
The -1,3-oxazin-4-one derivative is extremely excellent as a herbicide and does not cause phytotoxicity to rice, which is a useful crop, and it is possible to see changes in efficacy and phytotoxicity due to external factors such as water leakage. It has been found that it has excellent characteristics that cannot be obtained. That is, the present invention has the general formula (I)

[0009]

[Chemical 4]

(In the formula, X represents a hydrogen atom or a fluorine atom.) 6-methyl-3- [1-methyl-1]
-(Benzothiazol-2-yl) ethyl] -5- (substituted phenyl) -2,3-dihydro-4H-1,3-oxazin-4-one derivatives, and herbicides containing the same Is.

6-Methyl-3- [1-methyl-of the present invention
1- (benzothiazol-2-yl) ethyl] -5-
(Substituted phenyl) -2,3-dihydro-4H-1,3-
The oxazin-4-one derivative is a novel compound, and can be produced by the method represented by the reaction formula (1).

[0012]

[Chemical 5]

That is, 2,2-represented by the general formula (II) (in the formula, X represents a hydrogen atom or a fluorine atom).
The dimethyl-1,3-dioxin-4-one derivative can be produced by reacting the compound represented by the general formula (III) with a suitable solvent or no solvent.

The suitable solvent used in this reaction is not particularly limited as long as it is inert, but it is desirable to use a high boiling organic solvent such as toluene, xylene or mesitylene. The reaction temperature can be 20 to 160 ° C. or a temperature between the boiling points of the solvents used. The reaction time varies depending on the reaction conditions used, but generally it can be completed in 1 to 150 minutes. The ratio of the compound of the formula (III) to the compound of the formula (II) is also not strictly limited, but it is convenient to use it in the range of 0.6 to 2 equivalents, particularly 0.9 to 1.1 equivalents. .

In the above reaction, the compound of the above formula (II) used as a starting material can be prepared by a known method, for example, C
hem. Pharm. Bull. , 31 (6), 189
5 (1983).

Further, the compound (I) of the above reaction formula (1)
Of the formula (II
N-methylene-1-methyl-1- (benzothiazol-2-yl) ethylamine of I) is a novel compound which has not been previously described in the literature.

The compound of the above formula (III) can be produced by the method represented by the reaction formula (2).

[0018]

[Chemical 6]

That is, it is produced by reacting the amine represented by the general formula (IV) with formalin.

The reaction time can be completed in about 0.1 to 5 hours. The reaction temperature is 0 ° C to 100 ° C, preferably about room temperature.

In the above reaction, the compound of the above formula (IV) used as a starting material can be prepared by a known method, for example,
It can be produced by the method described in JP-A-6-25160.

The herbicide containing the compound of the present invention thus obtained as an active ingredient has, as its action characteristics, harmful weeds which are problematic in most paddy fields, for example, grass weeds such as Nobie, Cyperaceae such as Cyperaceae and Firefly. It has an excellent herbicidal effect on annual broadleaf weeds such as weeds and eels, and perennial weeds such as Urikawa. On the other hand, it is not harmful to rice, which is a useful crop. Further, the herbicides relating to the compound of the present invention, in all treatment methods such as water-resisting soil treatment, soil treatment, soil admixture treatment, from the generation period of weeds to the growth period after generation, over a wide period,
It can be used effectively.

The invention compound of the present application is the oxazine ring 3-
The above-mentioned prior art (WO-93 / 15064) in which a 1,3-oxazin-4-one derivative is disclosed in that a benzothiazol-2-yl group is present as a substituent at the position
Different from the compound described in. In improving the performance as a herbicide, the presence of a benzothiazol-2-yl group in the substituent at the 3-position of the oxazine ring is significant, and when the compound of the present invention is treated as a herbicide, it is clear from the test examples described below. As described above, even if there is water leakage, there is almost no phytotoxicity, and fluctuations in the effect are hardly observed, and it can be safely used with high effect even in a water leakage field. In addition, the phytotoxicity usually seen when paddy rice is planted shallowly is small.

When the compound represented by the general formula (I) according to the present invention is used as a herbicide, it is generally mixed with an inert liquid carrier or a solid to prepare a powder, granule, Used as a wettable powder, emulsion, flowable agent, etc. Further, an auxiliary agent can be added if necessary for formulation.

The carrier may be either solid or liquid as long as it is usually used for agricultural and horticultural chemicals, and is not limited to a particular carrier. For example, solid carriers include clay, talc, bentonite,
Examples thereof include mineral powders such as calcium carbonate, diatomaceous earth, and white carbon, vegetable powders such as soybean powder and starch, polymer compounds such as petroleum resin, polyvinyl alcohol and polyalkylene glycol, urea and waxes. Examples of the liquid carrier include various organic solvents such as xylene, methylnaphthalene, and alkylbenzene, various oils such as vegetable oil, and water.

As the auxiliary agent, a surfactant, a binder (eg, lignin sulfonic acid, alginic acid, polyvinyl alcohol, gum arabic, CMC sodium, etc.) usually used for agricultural and horticultural agents, a stabilizer (eg, antioxidant) For example, a phenolic compound, a thiol compound or a high fatty acid ester may be used, a phosphate may be used as a pH adjuster, and a light stabilizer may be used), or the like, if necessary, and these may be used alone or in combination. Further, in some cases, an industrial bactericidal agent, an antibacterial and antifungal agent, etc. may be added for antibacterial and antifungal agents.

As examples of the surfactant, nonionic, anionic, cationic and amphoteric surfactants can be used alone or as a mixture. As the nonionic, those obtained by adding alkylphenol, higher alcohol, alkylnaphthol, higher fatty acid, fatty acid ester or the like to ethylene oxide (such as X-77 or Neugen EA80) or propylene oxide are preferable. Examples of anionic compounds include alkylphenols, alkylnaphthols, higher alcohols, higher fatty acids, fatty acid esters, etc., which have been converted to alkyl sulfonates (such as neoperex), alkyl sulfate ester salts, phosphate ester salts, etc. preferable. Further, lignin sulfonate (such as sun extract) is one of the preferable examples.

The content of the compound represented by the general formula (I) in the herbicide according to the present invention varies depending on the formulation form, but is usually 0.01 to 20% by weight for powders and 1 to 50% by weight for wettable powders. , 0.01 to 10% by weight for granules, 0.1 to 50% by weight for emulsions, 0.1 to 50% by weight for flowable formulations, 1 to 5 for dry flowable formulations
0% by weight, preferably 0.1 to 3% by weight for powders, 10 to 40% by weight for wettable powders, 0.1 to 0.1% for granules.
5% by weight, 1-30% by weight for emulsion, 1-30% by weight for flowable formulation, 10-4 for dry flowable formulation
It is 0% by weight.

The content of the auxiliary agent is 0 to 80% by weight,
The content of the carrier is 100% by weight minus the contents of the active ingredient compound and the auxiliary agent.

The herbicides of the present invention represented by the general formula (I) are one or more of the other herbicides, or pesticides such as fungicides, insecticides and plant growth regulators, fertilizers, soil conditioners, etc. Of course, it can be used mixed with
A mixed preparation with these is also possible, and a synergistic effect can be expected in some cases.

[0031]

EXAMPLES Next, the production method of the compound of the present invention will be specifically explained with reference to examples. Example 1 6-Methyl-3- [1-methyl-1- (benzothiazol-2-yl) ethyl] -5-phenyl-2,3-dihydro-4H-1,3-oxazin-4-one [compound Production of No. 1] 1-Methyl-1- (benzothiazol-2-yl) ethylamine (1.76 g) was added with 35% formalin aqueous solution and reacted at room temperature for 1 hour. After the reaction was completed, 30 ml of water was added and the mixture was extracted with methylene chloride. After drying over anhydrous magnesium sulfate, it was concentrated with an evaporator to give N-methylene-1.
-Methyl-1- (benzothiazol-2-yl) ethylamine (1.87 g) was obtained. The obtained N-methylene-
1-Methyl-1- (benzothiazol-2-yl) ethylamine was dissolved in xylene (20 ml) and 5-phenyl-2,2,6-trimethyl-2H, 4H-1,3-dioxin-4-one was added. The mixture was added at room temperature and reacted for 30 minutes while heating under reflux. The reaction mixture was concentrated with an evaporator,
By performing silica gel column chromatography, 6-methyl-3- [1-methyl-1- (benzothiazol-2-yl) ethyl] -5-phenyl-2,3 of the present invention is obtained.
-Dihydro-4H-1,3-oxazin-4-one (1.97g) was obtained. The physical properties are described below. ¹ H NMR (270 MHz, CDCl ₃ ) δppm: 1.95 (9H, s), 5.41 (2H, s), 7.
18〜7.46 (7H, m), 7.79 (1H, d, J = 7.3Hz), 7.94 (1H, d, J = 8.1H
z) mp: 110-116 ℃ IRν film (cm ^-1 ): 1661

In the same manner as in Example 1, 6-methyl-3- [1-methyl-1- (benzothiazol-2-yl) ethyl] -5- (2-fluorophenyl) -2 according to the present invention was used. , 3-Dihydro-4H-1,3-oxazine-
4-one [Compound No.-2] was produced. The physical properties are described below. ¹ H NMR (270 MHz, CDCl ₃ ) δppm: 1.94 (9H, s), 5.40 (2H, s), 7.
00 ~ 7.50 (6H, m), 7.78 (1H, d, J = 7.2Hz), 7.93 (1H, d, J = 8.0H
z) IR ν film (cm ^-1 ): 1668

Formulation Examples and Test Examples Next, formulation examples and herbicidal activity test examples of the herbicide according to the present invention will be shown. Formulation Example 1 (Wettable powder) Compound (1) of the present invention: 20 parts by weight, neoperex (trade name, manufactured by Kao; sodium dodecylbenzenesulfonate): 2 parts by weight, Neugen EA80 (trade name, manufactured by Sanyo Kasei; poly Oxyethylene nonyl phenyl ether): 1
Parts by weight, white carbon: 5 parts by weight and diatomaceous earth 72
A wettable powder was obtained by thoroughly pulverizing and mixing parts by weight.

Formulation Example 2 (Wettable powder) Compound (2) of the present invention: 20 parts by weight, sodium alkylbenzene sulfonate: 2 parts by weight, polyoxyethylene alkylphenyl ether: 1 part by weight and syclite:
A wettable powder was obtained by thoroughly pulverizing and mixing 77 parts by weight.

Formulation Example 3 (Wettable powder) Compound (1) of the present invention: 50 parts by weight, white carbon:
5 parts by weight, polyoxyethylene alkylphenyl ether ammonium sulfate salt: 6 parts by weight, sodium lignin sulfonate: 2 parts by weight and diatomaceous earth: 37 parts by weight
The wettable powder was obtained by pulverizing and mixing using an et-O-mizer.

Formulation Example 4 (Dust) The compound (1) of the present invention: 3 parts by weight, sodium ligninsulfonate: 3 parts by weight, polyoxyethylene alkylaryl ether: 2 parts by weight and clay: 92 parts by weight are mixed and ground. A powder was obtained.

Formulation Example 5 (Granule) Compound (2) of the present invention: 0.3 part by weight, Neoperex (trade name, the same as above): 2 parts by weight, Sun Extract P25
2 (trade name, manufactured by Sanyo Kokusaku Pulp; sodium lignin sulfonate): 2 parts by weight, bentonite: 72.7 parts by weight and talc: 23 parts by weight, were mixed well, and then an appropriate amount of water was added to moisten the mixture. It was extruded and granulated with a small injection molding machine. This was air-dried at 30 to 60 ° C. and crushed, and then granulated to 0.3 to 2 mm with a granulator to obtain granules.

Formulation Example 6 (Granule) Compound (1) of the present invention: 0.5 part by weight, Gohsenol (G
Osenol) GL-05s (PV from Nippon Synthetic Chemical Industry)
A): 2 parts by weight, Sun Extract P252 (Sanyo Kokusaku Pulp Sodium Benzenesulfonate): 2 parts by weight and clay:
After thoroughly mixing 95.5 parts by weight, an appropriate amount of water was added to wet the mixture, and the mixture was extruded and granulated by an injection molding machine. This is air-dried at 60 to 90 ° C and crushed, and then 0.3 to 1 by a sizing machine.
The particle size was adjusted to mm to obtain a granule.

Formulation Example 7 (Emulsion) Compound (2) of the present invention: 10 parts by weight, Solpol 800A
(Trade name, manufactured by Toho Kagaku Co., Ltd .: a mixture of a nonionic surfactant and an anionic surfactant): 10 parts by weight and o-xylene: 80 parts by weight were mixed and dissolved to obtain an emulsion.

Formulation Example 8 (Flowable Agent) The compound (1) of the present invention: 5 parts by weight, sodium ligninsulfonate: 2 parts by weight, xanthan gum: 0.3 part by weight and polyoxyethylene alkylaryl ether: 1 part by weight, Water: 91.7 parts by weight was added and mixed, and then finely pulverized using a sand grinder to obtain a flowable agent.

Formulation Example 9 (Dry flowable) Finely ground compound (1) of the present invention: 60 parts by weight, sodium alkylbenzenesulfonate: 5 parts by weight and polypropylene glycol polyethylene glycol ether: 3
5 parts by weight were mixed to obtain a dry flowable agent.

Test Example 1 Flooded soil treatment (pre-emergence treatment) 1/500000 hectares Wagner pots were filled with soil, watered and dewatered, and then sea bream, firefly,
Seeds of eels and azaleas were sown to establish a submerged state. Two rice seedlings (2 to 3 leaf stage) that had been raised in advance were used as one strain, and the two strains were transplanted and grown in a greenhouse. One day later (before the emergence of weeds), a prescribed amount of the test compound was treated with a wettable powder prepared according to the method described in Formulation Example 1 above. The submersion depth was kept at 3 cm, and from the day after the treatment, 1 cm of water leakage was given for 10 days by a method in which water in the pot was dripped out from the bottom of the pot through a glass tube. Processing 30
After a day, we observed and investigated the occurrence of weeds and the damage to rice plants. The results are shown in Table 1 (Table 1). In the table, the degree of damage to the test plant and the degree of chemical damage to paddy rice are shown based on the following criteria in comparison with the wind dry weight in the case of no treatment.

Growth rate (%) shown by air dry weight ratio vs. label vs. untreated plot 100 0 to 5 9 6 to 10 8 11 to 20 7 21 to 30 6 31 to 40 5 41 to 60 4 61 to 70 3 71 to 80 2 81 to 90 1 91 to 95 0 96 to 100

Comparative compounds A and B represent the following compounds. (Same for Test Example 2) A: 6-methyl-3- [1-methyl-1- (3,5-dichlorophenyl) ethyl] -5-phenyl-2,3-dihydro-4H-1,3-oxazine- 4-one B: 6-methyl-3- [1-methyl-1- (3-chlorophenyl) ethyl] -5-phenyl-2,3-dihydro-4H-1,3-oxazin-4-one (Comparative compound A and B are the compounds described in WO-93 / 15064.)

[0045]

[Table 1]

In this test, the herbicide according to the present invention is
It showed a high herbicidal effect on the paddy field weeds tested at low dosage, and showed excellent safety against paddy rice. Comparative compounds A and B showed phytotoxicity to paddy rice at the dose that completely killed weeds.

Test Example 2 Flooded Soil Treatment (Growth Stage Treatment) 1/500000 hectare Wagner pots were filled with soil, watered and dewatered, and then sea bream, firefly,
Seeds of eels and azaleas were sown to establish a submerged state. Two rice seedlings (2 to 3 leaf stage) that had been raised in advance were used as one strain, and the two strains were transplanted and grown in a greenhouse. When the leaf-latch was in the 2 leaf stage, it was treated with a wettable powder prepared by adjusting a predetermined amount of the test compound according to the method described in the above Preparation Example 2. Keep the submersion depth at 3 cm, and from the day after the treatment,
A method of allowing water in the pot to drip out from the bottom of the pot with a glass tube was supplied with 1 cm of water leakage per day for 10 days.
Thirty days after the treatment, the occurrence of weeds and the chemical damage to paddy rice were observed and investigated. The results are shown in Table 2 (Tables 2 to 3).
It was shown to. In the table, the degree of damage to the test plant and the degree of chemical damage to paddy rice are shown in the same manner as in Test Example 1.

[0048]

[Table 2]

[0049]

[Table 3]

In this test, the herbicide according to the present invention is
Even in the low-dose treatment, it showed a high herbicidal effect against the paddy field weeds tested and showed excellent safety against paddy rice. Comparative compounds A and B showed phytotoxicity to paddy rice at the doses for killing weeds.

Test Example 3 Chemical damage test according to depth of rice planting 1/50000 hectare Wagner pots were filled with soil, and water was admitted and puddled. Two rice seedlings (2 to 3 leaf stage) that had been raised in advance are used as one strain, and the transplantation depth is 1c.
Two strains each were transplanted at m and 2 cm and grown in a greenhouse. One day later, a prescribed amount of the test compound was added to the above-mentioned Preparation Example 2
Treatment was performed using a wettable powder prepared according to the method described in 1. The submerged depth was kept at 3 cm, and the plant was then grown in a greenhouse. Thirty days after the treatment, the phytotoxicity of paddy rice was observed and investigated. The results are shown in Table 3 (Table 4). In the table, the degree of phytotoxicity to paddy rice is indicated as in Test Example 1.

[0052]

[Table 4]

In this test, the herbicide according to the present invention is
It showed excellent safety even for paddy rice planted with 1 cm. Comparative compounds A and B show 1c even in low dose treatment.
It showed strong phytotoxicity to rice planted in m.

[0054]

EFFECTS OF THE INVENTION 6-Methyl-3- [1-methyl-1- (benzothiazol-2-yl) ethyl] -5- (substituted phenyl) -2 represented by the general formula (I) according to the present invention. ，
The 3-dihydro-4H-1,3-oxazin-4-one derivative is a novel compound, and a herbicide containing the compound of the present invention is effective against various weeds that are problematic in paddy fields before and after the outbreak. It shows herbicidal activity at a low dose until the growing season. In addition, it shows excellent selectivity to rice, and it shows stable selectivity to leaked rice fields and shallowly planted rice, so it can be used safely.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Sadafumi Eda 1144, Togo, Mobara-shi, Chiba Mitsui Toatsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. General formula (I) (Chemical formula 1) (In the formula, X represents a hydrogen atom or a fluorine atom.) 6-methyl-3- [1-methyl-1- (benzothiazol-2-yl) ethyl] -5- (substituted phenyl)
-2,3-Dihydro-4H-1,3-oxazine-4-
On derivative. 2. The general formula (I) (Chemical Formula 2) (In the formula, X represents a hydrogen atom or a fluorine atom.) 6-methyl-3- [1-methyl-1- (benzothiazol-2-yl) ethyl] -5- (substituted phenyl)
-2,3-Dihydro-4H-1,3-oxazine-4-
A herbicide containing an on derivative.