JP3117384B2 - Furobenzopyran derivatives and herbicides containing them as active ingredients - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel furobenzopyran derivative and a herbicide containing the same as an active ingredient.

[0002]

2. Description of the Related Art Very few compounds having a furobenzopyran ring are synthesized. Only the compounds described in JP-A-6-3165793 show herbicidal activity. That is, Japanese Patent Application Laid-Open No. 6-3165793 describes a furobenzopyran derivative represented by the general formula (II) (Formula 2).

[0003]

Embedded image [Wherein R ₁ represents a lower alkyl group, R ₂ represents a lower alkyl group, a lower alkoxy group, a halogen atom or a halogen-substituted lower alkyl group, and R ₃ represents a lower alkyl group, a lower alkoxy group, a halogen atom, a halogen-substituted group. Represents a lower alkyl group, a phenoxy group or a benzyloxy group,
R ₄ represents a hydrogen atom or a lower alkyl group;
Represents an integer of 0 to 4, and when m and n are 2 to 4, R ₂
And R ₃ may be the same or different. In addition, only monoserine (MONOCERIN) represented by the following structural formula (Formula 3) has been reported to exhibit a physiological activity as a furobenzopyran derivative.

[0004]

Embedded image This compound is described as an antibacterial metabolite of Helminthosporium monoceras by J.I. Chem. Soc. (C) 2598
(1970). Further, it is described in US Pat. No. 3,661,935 as an antibacterial compound.

[0005]

Many herbicides for fields or paddy fields have been developed to date, but there is no sufficient herbicidal activity or selectivity for crops. JP 6
In some cases, furobenzopyran derivatives described in JP-A-3165793 have insufficient selectivity to crops under severe water leakage conditions. Therefore, an object of the present invention is to find a compound which does not cause harm to useful crops under any conditions and has excellent herbicidal activity when used in fields and paddy fields. That is, while the present invention is sufficiently safe for paddy rice, it shows strong herbicidal activity against annual weeds such as Nobie, Tamayatsuri, Konagi, Kikushigusa and perennial weeds such as fireflies, Spodoptera striata, Krogwai, and Pineby, and is useful for rice. An object is to find a compound having excellent performance as a herbicide. In addition, by soil treatment or foliage treatment in the field, it is also effective on rice, rice, etc. Not only as a herbicide for
An object is to find a compound that is also effective as a field-acting herbicide.

[0006]

Means for Solving the Problems and Actions The present inventors have synthesized a large number of novel furobenzopyran compounds in order to solve the above-mentioned problems, and have studied variously on their herbicidal activity. As a result, they have found a compound that is not only effective as a rice herbicide but also effective as a field-acting herbicide, and completed the present invention. That is, the present invention provides a compound represented by the general formula (I)
(Formula 4)

[0007]

Embedded image [Wherein R ₁ represents a lower alkyl group, R ₂ represents a lower alkyl group, a lower alkoxy group, a halogen atom or a halogen-substituted lower alkyl group, and R ₃ represents a lower alkyl group, a lower alkoxy group, a halogen atom, a halogen-substituted group. Lower alkyl group, halogen-substituted lower alkoxy group or group -O
Represents {C (R ₆ ) ₂ } _p- O- (connecting adjacent carbon atoms on a benzene ring to form a 5- or 6-membered ring),
中 In the formula, R ₆ represents a hydrogen atom, a lower alkyl group or a halogen atom, and p represents 1 or 2. ｝ R ₄ may be substituted with a halogen atom, a hydroxyl group, a lower alkoxy group, a lower acyloxy group or a lower alkylthio group
Represents a lower alkyl group, R ₅ represents a hydrogen atom or a lower alkyl group. However, when R ₄ is a lower alkyl group, R ₅ represents a lower alkyl group.あ る い は, or R ₄ and R ₅ together represent a carbonyl group or a thiocarbonyl group, m and n represent an integer of 0 to 4, and when m and n are 2 to 4, R ₂ and R ₃ represent They may be the same or different. And a herbicide containing the same as an active ingredient.

In the compound of the present invention, a lower alkyl group,
A lower alkoxy group, a lower acyloxy group or a lower alkylthio group means an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, an acyloxy group having 1 to 4 carbon atoms or an alkylthio group having 1 to 4 carbon atoms, respectively. And halogen atom refer to fluorine atom, chlorine atom, bromine atom and iodine atom. The compound (I) of the present invention is a novel compound,
These are represented by the following general formula (I) according to the following reaction formula (1)
It can be produced by subjecting the tetrahydrofuran derivative represented by II) to an intramolecular cyclization reaction.

[0009]

Embedded image (Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , m and n represent the above-mentioned meanings, and R ₇ represents a lower alkyl group or a lower acyl). In an inert solvent such as n-hexane, nitrobenzene, chlorobenzene, methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, carbon disulfide, acetonitrile, tin tetrachloride, titanium tetrachloride, aluminum chloride, chloride Intramolecular cyclization in the presence of Lewis acids such as diiron, boron trifluoride diethyl ether complex, or mineral or organic acids such as sulfuric acid, nitric acid, hydrochloric acid, chlorosulfonic acid, phosphoric acid, benzenesulfonic acid, and trifluoromethanesulfonic acid It is obtained by reacting. The reaction temperature can be from −70 ° C. to the boiling point of the solvent, but it is more advantageous to conduct the reaction in a relatively low temperature range.
0 ° C. After completion of the reaction, post-treatment is carried out as usual, and the target compound can be obtained by recrystallization or purification by column chromatography. The compound represented by the general formula (I) of the present invention obtained here is obtained as two diastereomers when R ₄ and R ₅ are different substituents. This diastereomer mixture can be separated by silica gel chromatography or the like, and both compounds have high herbicidal activity. Thus, the present invention includes both diastereomers.

The compound represented by the general formula (I) of the present invention can be produced by another reaction route other than the step A. For example, the compound in which R ₄ is a lower alkyl group (substituted with a hydroxyl group, a lower alkoxy group, a lower acyloxy group or a lower alkylthio group) is also a compound obtained by the step A in which R ₄ is a halogen-substituted lower alkyl group. Can be manufactured. One example is shown in the following reaction formula (2) (Chem. 6).

[0011]

Embedded image (In the formula, R ₁ , R ₂ , R ₃ , R ₅ , m and n have the above-mentioned meanings, and R ₉ represents a hydrogen atom, a lower alkyl group or a lower acyl group.) In this reaction example, R ₄ is Using the compound (Ia) which is a bromomethyl group as a raw material, the compound represented by the general formula (I)
The compound represented by -b) is obtained. That is, compound (Ia) is converted into n-hexane, benzene, toluene, xylene, diethyl ether, dioxane, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide,
In an inert solvent such as chlorobenzene, methyl ethyl ketone, acetone, or acetonitrile, in the presence of an inorganic base such as potassium carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride, or sodium amide, an equivalent amount or a slight excess of the general formula The compound (Ib) is obtained by reacting with the compound represented by R ₉ OH. The reaction temperature can be from 0 ° C. to the boiling point of the solvent, but it is more advantageous to carry out the reaction preferably at room temperature to 40 ° C. By reacting with lower alkylmercaptan in step B, a compound in which R ₄ is a lower alkylthio group can be easily obtained. After completion of these reactions, post-treatments are carried out as usual, and the target compound can be purified by recrystallization or column chromatography.

Next, the compound (I) in which the 5-position is a carbonyl group
The production example of -c) other than the step A is shown in the following reaction formula (3) (Formula 7).

[0013]

Embedded image (Wherein R ₁ , R ₂ , R ₃ , m and n represent the above-mentioned meanings, R ₁₀ represents a protecting group such as a tert-butyldimethylsilyl group, and Z represents a reactivity such as a halogen atom and an ester residue. This reaction is composed of three steps C, D and E.
That is, in step C, the 5-position of compound (IV) is oxidized to give δ-
After the lactone, the substituent R ₁₀ is deprotected in Step D,
Reaction with a (substituted) benzyl derivative in step E gives compound (Ic).

In the step C, the compound (IV) is converted into an inert solvent such as n-hexane, benzene, toluene, xylene, dioxane, dimethylformamide, dimethylsulfoxide, chlorobenzene, methylene chloride, chloroform, methyl ethyl ketone, acetone, acetic acid, acetic anhydride and the like. Medium, by reacting with an oxidizing agent such as ruthenium (IV) oxide and t-butyl chromate, the 5-position is selectively oxidized to a carbonyl group. The reaction temperature can be from −30 ° C. to the boiling point of the solvent, but it is more advantageous to carry out the reaction preferably at room temperature to 40 ° C.

Next, in step D, T.W. W. Greene
and P.S. G. FIG. M. Wuts, "Protective
e Groups in Organic Synth
ess "; John Wiley & Sons, I
nc. Following the general deprotection conditions for silyl protecting groups described in books such as New York, 1991;
Deprotect. For example anhydrous conditions, tetrahydrofuran, deprotecting a substituent group R ₁₀ by the action of a solvent in a fluorine anion such as acetonitrile. The reaction temperature can be from room temperature to the boiling point of the solvent, but is preferably 10 ° C.
It is more advantageous to carry out the reaction in the range of from 30 to 30 ° C.

In the step E, n-hexane, benzene, toluene, xylene, diethyl ether, dioxane, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, chlorobenzene, methylene chloride, chloroform, methyl ethyl ketone, acetone, acetonitrile, etc. In the presence of an inorganic base such as potassium carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride, sodium amide, etc., 3-
The compound (Ic) is obtained by reacting the hydroxy form with an equal or slightly excess (substituted) benzyl halide. Alternatively, the reaction can be performed in a two-layer system of an organic solvent such as benzene or toluene and water in the presence of a phase transfer catalyst such as a quaternary ammonium salt or a phosphate. The reaction temperature can be from 0 ° C. to the boiling point of the solvent, but preferably the reaction is carried out in the range of room temperature to 60 ° C. By reacting the compound (Ic) obtained here with phosphorus pentasulfide or Lawesson's reagent, a thiocarbonyl compound at the 5-position can be easily obtained. After completion of these reactions, post-treatments are carried out as usual, and the target compound can be purified by recrystallization or column chromatography.

The compound (II) used as a starting material in Step A
Although some novel compounds are included in I), they can be generally synthesized by well-known reactions. As an example, the following two reaction routes, namely, reaction formula (4) (formula 8) and reaction formula (5)
(Formula 9) was shown.

[0018]

Embedded image

[0019]

Embedded image (Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₇ , Z, m and n represent the above-mentioned meanings, and R ₈ represents a hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms. In step F, compounds (V) and (VI) were converted to n-hexane, benzene, toluene, xylene, diethyl ether, dioxane, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, chlorobenzene, methylene chloride, chloroform, methyl ethyl ketone, acetone 70% of the catalyst amount in an inert solvent such as water and acetonitrile
Reaction with an equal or excess amount of N-chlorosuccinimide or N-bromosuccinimide in the presence of perchloric acid gives compound (III) wherein R ₄ is a halogen-substituted lower alkyl group. The reaction temperature can be from -10 ° C to the boiling point of the solvent, but it is more advantageous to carry out the reaction preferably at room temperature to 40 ° C. After completion of the reaction, post-treatment is carried out as usual, and the target compound can be purified by recrystallization or column chromatography. The compound of the formula (III) wherein R ₇ is an acyl group can be obtained from a compound of the formula (III) wherein R ₇ is an alkyl group by a known general method (for example, Chem. I).
nd. , 27 , 547 (1968)).

In the step G, the compound of the general formula (V) is
Hexane, benzene, toluene, xylene, diethyl ether, dioxane, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, chlorobenzene,
In an inert solvent such as methylene chloride, chloroform, methyl ethyl ketone, acetone and acetonitrile, in the presence of an inorganic base such as potassium carbonate, sodium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride, sodium amide, or silver oxide, The compound (III) is obtained by reacting with an equivalent amount or a slight excess of the compound of the general formula (VII). The reaction temperature can be from 0 ° C. to the boiling point of the solvent, but preferably the reaction is carried out in the range of room temperature to 60 ° C. After completion of the reaction, post-treatment is carried out as usual, and the target compound can be purified by recrystallization or column chromatography.

Compound (III) obtained in steps F and G
Are α and β in almost the same ratio as compound (V) as a raw material.
It becomes a mixture of two isomers of the anomer. These can be separated into isomers by silica gel chromatography or the like, and can be used for the next reaction after separation. The compound of the general formula (V) used as a raw material in the steps F and G is a known compound. Org. Chem. , 50 , 4786 (19
85) and US Pat. No. 4,534,785. Usually, they are obtained as a mixture of α- and β-forms, but it is also possible to separate the isomers by silica gel chromatography or the like and use them in the next reaction.

The compound of the present invention has significantly higher safety to crops than the comparative compound under water-leakage conditions in which phytotoxicity is likely to occur. That is, the compound of the general formula (I) of the present invention is
In addition to being extremely excellent in safety against paddy rice, it shows strong herbicidal activity against annual weeds such as nobies, tamayatsuri, konagi and kikashigusa, as well as perennial weeds such as fireflies, shrubs, kurogwaii and matsubayashi, and is an excellent herbicide for paddy rice. Has performance. In addition, soybean, cotton, sugar beet, corn, sugarcane, wheat and other useful crops in any of the soil treatment or foliage treatment, and has high selectivity to useful crops, such as Meechishiba, Hakobe, Tade, Inubiyu, Kogomeyatsuri, Suberihigyu, Noborogiku, Shiroza, hamasuge,
Convolvulus, clover, yamgra, sparrow,
It exhibits herbicidal activity against Poa annua, Brassica napus, Enochorogusa, etc., and is effective not only as a herbicide for paddy rice but also as a field-acting herbicide.

The compound (I) of the present invention may be used as it is for the plant to be treated, but it is generally mixed with an inert liquid or solid to prepare a generally used preparation.
For example, it is used after adjusting to powders, granules, wettable powders, emulsions, flowable preparations and the like. If necessary for the preparation, an auxiliary agent can be added.

As the carrier, any solid or liquid carrier can be used as long as it is generally used for agricultural and horticultural medicines, and it is not limited to a specific one. For example, solid carriers include mineral powders such as clay, talc, bentonite, calcium carbonate, diatomaceous earth, white carbon, etc., vegetable powders such as soybean powder, starch, petroleum resins, polyvinyl alcohol, polyalkylene glycols and the like. Molecular compounds, urea, waxes and the like. Examples of the liquid carrier include various oils, various organic solvents, water and the like. Surfactants, binders, stabilizers and the like which are usually used for agricultural and horticultural medicines can be used alone or in combination as necessary. Further, in some cases, an industrial bactericide or a bactericidal / antifungal agent can be added for bactericidal / fungal control.

As the surfactant, a nonionic, anionic, cationic or amphoteric surfactant can be used as appropriate. Preferred examples include alkyl phenols, higher alcohols, alkyl naphthols, higher fatty acids, fatty acid esters, dialkyl phosphate amines and the like, which are obtained by polymerizing ethylene oxide and propylene oxide, alkyl sulfate salts (such as sodium lauryl sulfate), and alkyl sulfonate salts. (Sodium 2-ethylhexene sulfonate, etc.), aryl sulfonates (sodium lignin sulfonate, sodium dodecylbenzene sulfonate, etc.)
Is raised. The content of the compound of the general formula (I) in the herbicide according to the present invention varies depending on the form of preparation, but is usually 1 to 20% by weight for powder and 20 to 6 for wettable powder.
0% by weight, 1-30% by weight for granules, 1-50% for emulsions
%, 10 to 50% by weight for the flowable preparation, and 20 to 90% by weight for the dry flowable preparation. The content of the adjuvant is 0 to 80% by weight, and the content of the carrier is 10%.
It is the amount obtained by subtracting the contents of the active ingredient compound and the adjuvant from 0% by weight.

The herbicide according to the present invention can be used for treating flooded soil,
It is effective in all treatment methods such as soil treatment, soil mixed layer treatment, foliage spraying treatment, and can be used in a wide range of 0.01 kg to 10 kg / ha as an active ingredient as an application rate. Is preferably used in the range of 0.05 kg / ha to 5 kg / ha. The herbicide of the present invention can be used in combination with one or more other herbicides, pesticides such as insecticides, plant growth regulators, soil improvers or fertilizers, It is also possible to prepare a mixed preparation with these, and a synergistic effect can be expected in some cases. In this case, it is particularly advantageous to use it as a mixture with other herbicides. Other herbicides include, for example, phenoxyacetic acid herbicides, benzoic acid herbicides, chlorinated carboxylic acid herbicides, carbamate herbicides, urea herbicides, sulfonylurea herbicides, acid amide herbicides, complex Cyclic herbicides (triazine herbicides, diazine herbicides, etc.), phenolic herbicides, diphenyl ether herbicides, dipyridinium herbicides, dinitroaniline herbicides, organophosphate herbicides, phosphorus-containing amino acids Herbicides, imidazolidinone herbicides, pyridine herbicides,
Examples include quinoline herbicides, sulfonamide herbicides, cyclohexanone herbicides, other organic herbicides, and inorganic herbicides.

[0027]

Next, the present invention will be described in more detail by way of examples. First, Production Examples of Compound (V) will be shown as Reference Examples. Reference Example 1 Production of methyl 5-deoxy-3-O- (2-chlorobenzyl) -5-C-methyl-D-xylofuranoside 3-O- (2-chlorobenzyl) -5-deoxy-1,
2-O-isopropylidene-5-C-methyl-α-D-
67.97 g of xylofuranoose was added to methanol (300 m
After dissolving in 1), 0.5 g of p-toluenesulfonic acid was added.
Was added and the mixture was heated under reflux for 10 hours. After cooling, the reaction solution was neutralized with an aqueous sodium hydrogen carbonate solution, and the solvent was distilled off under reduced pressure.
This was added to water, extracted with a mixed solvent of ether and ethyl acetate (1: 1), and the organic layer was washed with water. This was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to obtain an oily crude product. This was purified by silica gel chromatography (developing solvent; n-hexane: ethyl acetate = 3: 1) to obtain 54.51 g of the target compound as an anomeric mixture of α-form and β-form (yield 98.2%). . The anomeric mixture of α-form and β-form obtained here was precisely purified by silica gel chromatography (developing solvent; n-hexane: ethyl acetate = 5: 1), and separated into α-form and β-form.

Reference Example 2 Preparation of methyl 5-deoxy-3-O- (2-methylbenzyl) -D-xylofuranoside 5-deoxy-3-O- (2-methylbenzyl) -1,
After dissolving 10.68 g of 2-O-isopropylidene-α-D-xylofuranoose in methanol (100 ml), 0.5 g of p-toluenesulfonic acid was added, and the mixture was heated under reflux for 10 hours. After cooling, the same post-treatment as in Reference Example 1 was performed.
9.25 g of the target compound was obtained as an anomeric mixture of α-form and β-form (yield 95.6%). Next, a production example of the compound (I) of the present invention via the step (F) and the step (A) will be described.

Example 1 (2R, 3S, 3aS, 9bR) -3- (2-chlorobenzyloxy) -5-bromomethyl-2-ethyl-5
Preparation of methyl-3,3a, 5,9b-tetrahydro-2H-furo [3,2-c] [2] benzopyran (compound No. 17 of general formula (I)) 1) Methyl 3-O- (2-chloro Benzyl) -5-deoxy-5-C-methyl-2-O- (1-methyl-1-
Preparation of phenyl-2-bromoethyl) -D-xylofuranoside Methyl 5-deoxy-3-O- (2-
(Chlorobenzyl) -5-C-methyl-D-xylofuranoside 10.00 g, α-methylstyrene 8.30 g,
12.43 g of N-bromosuccinimide was dissolved in 100 ml of tetrahydrofuran and stirred. 0.10 ml of perchloric acid was added at room temperature, and the mixture was stirred at room temperature for 7 hours. The reaction solution was poured into ice water and extracted with ethyl acetate. The organic layer was washed with a saturated aqueous solution of sodium hydrogencarbonate and saturated saline, and then dried over anhydrous sodium sulfate. The oily crude product obtained by evaporating the solvent under reduced pressure was purified by silica gel chromatography (developing solvent; n-hexane: ethyl acetate = 9: 1) to obtain 13.28 g of the desired compound as pale yellow (Yield 78.0%). _{^{1 H-NMR (CDCl 3,}} 270MHz) δ: 0.92 (3H, t, J = 7.3Hz), 1.55~1.
69 (3H, m), 1.75-2.04 (2H, m), 3.17 & 3.38 (3H, each s), 3.5
8 to 3.74 (2H, m), 3.83 to 3.88 (1H, m), 3.92 to 3.98 (1H, m) 4.0
2 to 4.22 (2H, m), 4.52 to 4.89 (2H, m), 6.96 to 7.55 (9H, m)

2) (2R, 3S, 3aS, 9bR) -3
-(2-chlorobenzyloxy) -5-bromomethyl-
Preparation of 2-ethyl-5-methyl-3,3a, 5,9b-tetrahydro-2H-furo [3,2-c] [2] benzopyran Methyl 3-O- (2-chlorobenzyl) obtained by 1) ) -5-Deoxy-5-C-methyl-2-O (1
After dissolving 7.00 g of -methyl-1-phenyl-2-bromoethyl) -D-xylofuranoside in 50 ml of dichloromethane and stirring, 4.11 g of a boron trifluoride-diethyl ether complex was added under ice-cooling, followed by stirring for 3 hours. The mixture was poured into a saturated aqueous sodium hydrogen carbonate solution containing ice, and extracted with dichloromethane. The organic layer was washed with saturated saline, dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to obtain an oily crude product. The crude product was subjected to silica gel chromatography (developing solvent; n-hexane: ethyl acetate =
Purification was performed at 9: 1) to obtain 5.43 g of the target compound as a colorless syrup (yield: 83.0%). Next, a production example of the compound (I) by the step (B) will be described.

Example 2 (2R, 3S, 3aS, 9bR) -3- (2-chlorobenzyloxy) -2-ethyl-5-methoxymethyl-5
-Methyl-3,3a, 5,9b-tetrahydro-2H-
Flow [3,2-c] [2] benzopyran (general formula (I)
Preparation of compound No. 26) of (2R, 3S, 3a) obtained by 2) of Example 1
S, 9bR) -3- (2-Chlorobenzyloxy) -5
-Bromomethyl-2-ethyl-5-methyl-3,3a,
5,9b-tetrahydro-2H-furo [3,2-c]
[2] 2.00 g of benzopyran and 2.39 g of sodium methylate were dissolved in 30 ml of N, N-dimethylformamide and stirred at 100 ° C. for 9 hours. The mixture was poured into ice water and extracted with ethyl acetate. The organic layer was washed with water and saturated saline and dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to obtain an oily crude product. The crude product was purified by silica gel chromatography (developing solvent; n-hexane: ethyl acetate = 9: 1) to obtain 1.20 g of the desired compound as a pale yellow syrup (yield: 67.0%). Next, production examples of the compound (I) by the steps (C) to (E) will be described.

Example 3 (2R, 3S, 3aS, 9bR) -2-ethyl-3-
(2-methylbenzyloxy) -3,3a, 5,9b-
Preparation of tetrahydro-2H-furo [3,2-c] [2] benzopyran-5-one (compound No. 34 of general formula (I)) 1) (2R, 3S, 3aS, 9bR) -3- (tert)
-Butyldimethylsilyloxy) -2-ethyl-3,3
a, 5,9b-Tetrahydro-2H-furo [3,2-
c] Preparation of [2] benzopyran-5-one (2R, 3S, 3aS, 9bR) -3- (tert-butyldimethylsilyloxy) -2-ethyl-3,3a,
5,9b-tetrahydro-2H-furo [3,2-c]
[2] 6.63 g of benzopyran was dissolved and stirred in 30 ml of carbon tetrachloride, and 0.79 g of ruthenium (IV) oxide, 16.96 g of sodium metaperiodate and 50 ml of water were added, followed by stirring at room temperature for 5 hours. After filtration through celite, 50 ml of 2-propanol was added, stirred, and extracted with dichloromethane. The organic layer was washed with brine and dried over anhydrous sodium sulfate. The crude product obtained by evaporating the solvent under reduced pressure was purified by silica gel chromatography (developing solvent; n-hexane: ethyl acetate = 5: 1) to obtain the desired compound 6.
29 g were obtained as a pale yellow syrup. (Yield 91.0
%) IRν _max (film) cm ^-1 : 2956,2883,2858,1736,16 08,1463,1
363,1264,1215 ¹ H-NMR (CDCl ₃ , 270 MHz) δ: 0.16 (6H, s), 0.94 (12H, s), 1.5
8 ~ 1.78 (2H, m), 4.15 ~ 4.22 (1H, m), 4.48 (1H, m), 4.82 (1
H, br), 5.06 (1H, d, J = 3.0Hz), 7.53-7.66 (3H, m), 8.15-
8.1 8 (1H, m)

2) (2R, 3S, 3aS, 9bR) -2
Preparation of -ethyl-3-hydroxy-3,3a, 5,9b-tetrahydro-2H-furo [3,2-c] [2] benzopyran-5-one 1) (2R, 3S, 3aS, 9bR)
-3- (tert-Butyldimethylsilyloxy) -2
-Ethyl-3,3a, 5,9b-tetrahydro-2H-
Flow [3,2-c] [2] benzopyran-5-one4.
58 g was dissolved in 50 ml of tetrahydrofuran, and 15.8 ml of tetra-n-butylammonium fluoride (1.0 M solution in tetrahydrofuran) was added under ice-cooling, followed by stirring at room temperature for 2 hours. The solvent was distilled off under reduced pressure, the residue was dissolved in ethyl acetate, washed with water and saturated saline, and dried over anhydrous sodium sulfate. The crude product obtained by evaporating the solvent under reduced pressure was subjected to silica gel chromatography (developing solvent; n).
-Hexane: ethyl acetate = 2: 1) to give 2.90 g of the desired compound as white crystals (yield 94.
0%). mp.:114.8-115.8°C IRν _max (film) cm ^-1 : 3367,3039,2984,2937,29 15,1740,1
^{. 602,1460,1352,1287,1253,12 17,1128 1 H-NMR (} CDCl 3, 270MHz) δ: 1.00 (3H, t, J = 7.3 Hz), 1.65~
1.84 (2H, m), 2.23 (1H, d, J = 4.4 Hz), 4.20-4.26 (1H, m), 4.
57 ~ 4.60 (1H, m), 4.98 ~ 5.00 (1H, m), 5.14 (1H, d, J = 2.9H
z), 7.52-7.71 (3H, m), 8.16-8.19 (1H, m)

3) (2R, 3S, 3aS, 9bR) -2
-Ethyl-3- (2-methylbenzyloxy) -3,3
a, 5,9b-Tetrahydro-2H-furo [3,2-
c] Preparation of [2] benzopyran-5-one (2R, 3S, 3aS, 9bR) -2-ethyl-3-hydroxy-3,3a, 5,9b-tetrahydro-2H-furo [3] obtained in 2) , 2-c] [2] benzopyran-5
1.90 g of -one was dissolved in 20 ml of tetrahydrofuran, and 0.49 g of oily sodium hydride (product containing 40% of liquid paraffin) was gradually added with stirring. Further, 0.1 g of tetrabutylammonium iodide and α-bromo-o-
1.80 g of xylene was added, and the mixture was stirred at room temperature for 3 hours. Water was added little by little while cooling with ice, diluted hydrochloric acid was further added, and the mixture was extracted with ethyl acetate. The organic layer was washed with water, a saturated aqueous solution of sodium hydrogencarbonate and saturated saline, and dried over anhydrous sodium sulfate. The crude product obtained by evaporating the solvent under reduced pressure was purified by silica gel chromatography (developing solvent; n-hexane: ethyl acetate = 5: 1) to obtain the desired compound 2.
41 g were obtained as pale yellow crystals (yield 88.0%).

Examples 4 to 35 The compounds of the general formula (I) prepared in the same manner as in Examples 1 to 3 are shown in Table 1 (Tables 1 and 2), and their physical properties are shown in Table 2 (Tables 3 and 4).
4).

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

Formulation Examples and Test Examples Next, formulation examples and herbicidal activity test examples of the herbicides according to the present invention are 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 Daiichi Kogyo Seiyaku) Polyoxyethylene nonylphenyl ether): 1 part by weight, 10 parts by weight of white carbon, and 67 parts by weight of diatomaceous earth were sufficiently pulverized and mixed to obtain a wettable powder.

Formulation Example 2 (Wettable powder) Compound (6) of the present invention: 20 parts by weight, sodium alkylbenzenesulfonate: 2 parts by weight, polyoxyethylene alkylphenyl ether: 1 part by weight, white carbon: 10 parts by weight, and sieg Light: 67 parts by weight was well pulverized and mixed to obtain a wettable powder.

Formulation Example 3 (Wettable powder) Compound (16) of the present invention: 50 parts by weight, white carbon: 30 parts by weight, ammonium polyoxyethylene alkyl phenyl ether sulfate: 6 parts by weight, sodium lignin sulfonate: 2 parts by weight And diatomaceous earth: 12 parts by weight were pulverized and mixed well to obtain a wettable powder.

Formulation Example 4 (Floable agent) Compound (8) of the present invention: 5 parts by weight, sodium ligninsulfonate: 2 parts by weight, polyoxyethylene alkylaryl ether: 1 part by weight, water: 91.7 parts by weight Was added and mixed, and the mixture was pulverized using a sand grinder, and then 0.3 parts by weight of xanthan gum was added to obtain a flowable agent.

Formulation Example 5 (Floable agent) Compound (5) of the present invention: 30 parts by weight of sun extract P252 dissolved in 50 parts by weight of water (trade name, as described above): 10
Parts by weight were wet-pulverized and mixed, and then dissolved in 9.6 parts by weight of water, Kerzan S (trade name, manufactured by Kelco; xanthan gum): 0.2 part by weight and Deltop (trade name, manufactured by Takeda Pharmaceutical: organic iodine-based) Fungicide): 0.2 parts by weight were added and mixed to obtain a flowable agent.

Formulation Example 6 (Powder) Compound of the present invention (17): 1 part by weight, Emulgen 910
(Trade name, manufactured by Kao; polyoxyethylene nonyl phenyl ether): 0.5 part by weight and kaolin clay: 9
8.5 parts by weight were pulverized and mixed well to obtain a powder.

Formulation Example 7 (Powder) Compound (5) 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 were mixed and pulverized. A powder was obtained.

Formulation Example 8 (Water-dispersible granules) Compound (17) of the present invention: 55 parts by weight, toxanone 60P
N: 5 parts by weight, polyoxyethylene alkyl aryl ether: 5 parts by weight, and white carbon: 35 parts by weight are mixed well, then an appropriate amount of water is added to wet, and then extruded by a horizontal extrusion granulator. did. This is 30-60
After drying at 0 ° C and crushing, the granules were refined to 0.3 to 0.5 mm with a sizing machine to obtain a wettable powder for granules.

Formulation Example 9 (Granules) Compound (16) of the present invention: 3.0 parts by weight, Neoperex (trade name, as described above): 2 parts by weight, Sun extract P25
2 (trade name, manufactured by Sanyo Kokusaku Pulp; sodium ligninsulfonate): 2 parts by weight, 70.0 parts by weight of bentonite and 23 parts by weight of talc were mixed well, and then an appropriate amount of water was added to wet the mixture. And extruded by a horizontal extrusion granulator. This was air-dried at 30 to 60 ° C. and crushed, and then sized with a sizing machine to 0.3 to 1 mm to obtain granules.

Formulation Example 10 (granules) 0.5 part by weight of compound (4) of the present invention, gohsenol (Go)
senol) GL-05s (PVA manufactured by Nippon Synthetic Chemical):
2 parts by weight, sun extract P252 (sodium lignin sulfonate manufactured by Sanyo Kokusaku Pulp): 2 parts by weight, and clay: 95.
After 5 parts by weight were mixed well, an appropriate amount of water was added to wet, and then extruded and granulated by a horizontal extrusion granulator. This is air-dried at 60 to 90 ° C. and crushed, and then 0.3 to 1 with a sizing machine.
The mixture was sized to obtain a granule.

Formulation Example 11 (Emulsion) Compound (25) of the present invention: 10 parts by weight, Solpol 800
A (trade name, manufactured by Toho Chemical; 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 12 (Wettable powder) Compound (31) of the present invention: 20 parts by weight, sodium alkylbenzenesulfonate: 2 parts by weight, polyoxyethylene alkylphenyl ether: 1 part by weight, white carbon: 15 parts by weight, and sieg Light: 62 parts by weight was pulverized and mixed well to obtain a wettable powder.

Formulation Example 13 (Wettable powder) Compound (33) of the present invention: 50 parts by weight, white carbon: 30 parts by weight, ammonium polyoxyethylene alkylphenyl ether sulfate: 6 parts by weight, sodium lignin sulfonate: 2 parts by weight And diatomaceous earth: 12 parts by weight were pulverized and mixed well to obtain a wettable powder.

Formulation Example 14 (oil-in-water emulsion EW) Compound (34) of the present invention: 5 parts by weight, toxanone FW-1
0 (trade name, manufactured by Sanyo Chemical Industries; polymer-based anion): 4
Parts by weight, xanthan gum: 0.3 parts by weight, Deltop:
88.5 parts by weight of water was added to 0.2 parts by weight and 2 parts by weight of polyoxyethylene alkylaryl ether, and emulsified by a homomixer to obtain an oil-in-water emulsion EW.

Formulation Example 15 (oil in water type emulsion EW) Compound (25) of the present invention: 30 parts by weight, Gohsenol KH
-20 (trade name, manufactured by Nippon Synthetic Chemical Co .; protective colloid formation): 4 parts by weight, xanthan gum: 0.3 part by weight, Deltop (trade name, Takeda Pharmaceutical: organic iodine-based fungicide): 0.2 61.5 parts by weight of water was added to 4 parts by weight of the polyoxyethylene alkylaryl ether and 4 parts by weight of the polyoxyethylene alkylaryl ether, and the mixture was wet-pulverized and mixed to obtain an oil-in-water emulsion EW.

Formulation Example 16 (Water-dispersible granules) Compound (26) of the present invention: 50 parts by weight, toxanone 60P
N: 5 parts by weight, polyoxyethylene alkylaryl ether: 5 parts by weight, and white carbon: 40 parts by weight are mixed well, then an appropriate amount of water is added to wet, and then extruded by a horizontal extrusion granulator. did. This is 30-60
After drying at 0 ° C and crushing, the granules were refined to 0.3 to 0.5 mm with a sizing machine to obtain a wettable powder for granules.

Formulation Example 17 (granules) Compound (27) of the present invention: 3.0 parts by weight, Neoperex (trade name, as described above): 2 parts by weight, Sun extract P25
2 (trade name, manufactured by Sanyo Kokusaku Pulp; sodium ligninsulfonate): 2 parts by weight, 70.0 parts by weight of bentonite and 23 parts by weight of talc were mixed well, and then an appropriate amount of water was added to wet the mixture. And extruded by a horizontal extrusion granulator. This was air-dried at 30 to 60 ° C. and crushed, and then sized with a sizing machine to 0.3 to 1 mm to obtain granules.

Formulation Example 18 (granules) Compound (18) of the present invention: 1.0 part by weight, Gosenol GL-05s (PV manufactured by Nippon Synthetic Chemical Co., Ltd.)
A): 2 parts by weight, sun extract P252 (sodium lignin sulfonate manufactured by Sanyo Kokusaku Pulp): 2 parts by weight and clay:
After 95.0 parts by weight were mixed well, an appropriate amount of water was added to wet the mixture, and the mixture was extruded and granulated by a horizontal extrusion granulator.
This was air-dried at 60 to 90 ° C. and crushed.
A granule was obtained by sizing to 3 to 1 mm.

Test Example 1 Flooded soil treatment test (water leakage conditions,
Pre-emergence treatment) The soil was packed in a 1/5000 arel Wagner pot, and seeds of red snapper, conger, firefly, and azalea were sowed and flooded. Rice seedlings (2-
Two strains were used as one strain, and the two strains were transplanted and grown in a greenhouse. One day later (before weed development), the test compound
The particles were treated with a predetermined amount of granules (prepared according to the method described in Formulation Example 9) so that the dose was Kg / ha.
The immersion depth was maintained at 3 cm, and a water leak of 1 cm per day was given for 10 days from the day after the treatment by a method in which water in the pot was dripped out from the lower part of the pot through a glass tube. Thirty days after the treatment, the occurrence of weeds and the phytotoxicity of rice were observed and investigated. The results are shown in Table 3 (Table 5). In the table, the degree of damage to the test plant and the degree of phytotoxicity to the crop are indicated by the following criteria in comparison with the case where the growth state of the plant is untreated.表示 Indication Growth rate (%) 50 to 5 (death) 46 to 10 (Severe harm) 3 11-40 (Medium harm) 2 41-70 (Small harm) 171-90 (Slight harm) 0 91-100 (Harmless) 無───────

[0059]

[Table 5] Control drug: compound described in JP-A-6-165793 (VIII) (IX) (IX) (11)

[0060]

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[0061]

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Test Example 2 Flooded soil treatment test (water leakage conditions,
(Growing period treatment) The soil was packed in a 1/5000 arel Wagner pot, and seeds of red snapper, conger, firefly, and azalea were sown and flooded. Rice seedlings (2-
Two strains were used as one strain, and the two strains were transplanted and grown in a greenhouse. When the two-leaf flour shrimp became two leaves, a predetermined amount of granules (prepared according to the method described in Formulation Example 9) was treated so that the test compound had a dose of 3 kg / ha. The immersion depth was maintained at 3 cm, and a water leak of 1 cm per day was given for 10 days from the day after the treatment by a method in which water in the pot was dripped out from the lower part of the pot through a glass tube. Thirty days later, the occurrence of weeds and the phytotoxicity of rice were observed and investigated. The results are shown in Table 4 (Table 6). In the table, the degree of damage to the test plant and the degree of phytotoxicity to the crop are indicated in the same manner as in Test Example 1.

[0063]

[Table 6] The control drug was the same as in Test Example 1.

Test Example 3 Upland Soil Treatment Test (Pretreatment before Occurrence) A resin pot of 1/2500 ares was filled with soil, and this was filled with barnyardgrass, crabgrass, enokorogusa, chickweed, aobiu,
The soil mixed with soybeans and cotton seeds was covered with a soil of 1 to 2 cm, and grown in a greenhouse. One day later (before the emergence of weeds), a predetermined amount of wettable powder (prepared according to the method described in Formulation Example 1) was diluted with water so that the test compound had a dosage of 3 kg / ha, and 1 A spraying liquid amount equivalent to 10 L per are was sprayed uniformly on the soil surface using a pressurized micro sprayer. Thirty days after the application of the chemical, the growth of the weed and the phytotoxicity of the crop were observed and investigated. The results are shown in Table 5 (Table 7). In the table, the degree of damage to the test plant and the degree of phytotoxicity to the crop are indicated in the same manner as in Test Example 1.

[0065]

[Table 7]

Test Example 5 Upland Field Foliage Treatment (Growing Season Treatment) A 1/10000 ares resin pot was filled with soil, and this was filled with barnyardgrass, crabgrass, enokorogusa, chickweed, aobiu,
Soybeans and cotton were sown one by one and grown in a greenhouse. When each plant has 2-3 leaves, the test compound is 3 kg / ha.
A predetermined amount of a wettable powder (prepared according to the method described in Formulation Example 2) was diluted with water and adjusted to have a dosage of 1
Spraying was uniformly performed using a pressurized micro atomizer at a spraying liquid amount equivalent to 10 L per are. Thirty days after the application of the chemical, the growth of the weed and the phytotoxicity of the crop were observed and investigated. The results are shown in Table 6 (Table 8). In the table, the degree of damage to the test plant and the degree of phytotoxicity to the crop are indicated in the same manner as in Test Example 1.

[0067]

[Table 8]

[0068]

The compound of the present invention represented by the general formula (I) is a novel compound having a furobenzopyran ring,
Shows excellent herbicidal activity and selectivity. That is, when the compound of the present invention is used in a paddy field, it has excellent selectivity for paddy rice and shows a high herbicidal effect against important weeds such as foxtails, puppies, fireflies and azaleas. In addition, the compound of the present invention has high selectivity for crops such as soybeans and cotton even in upland cropping, and shows a high herbicidal effect on important weeds such as barnyardgrass, crabgrass, enokorogusa, chickweed, and bluegrass. Therefore, the compound of the present invention can be applied as a paddy and upland herbicide.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-8-268813 (JP, A) JP-A-7-188244 (JP, A) JP-A-8-268812 (JP, A) JP-A-8-68881 268814 (JP, A) JP-A-8-268815 (JP, A) JP-A-7-196412 (JP, A) JP-A-7-145010 (JP, A) JP-A-7-145007 (JP, A) JP-A-7-145008 (JP, A) JP-A-7-145009 (JP, A) JP-A-7-138111 (JP, A) JP-A-7-138260 (JP, A) JP-A-7-138110 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07D 493/04 C07D 493/14 CA (STN) REGISTRY (STN)

Claims (5)

(57) [Claims] 1. A compound of the general formula (I) [Wherein R ₁ represents a lower alkyl group, R ₂ represents a lower alkyl group, a lower alkoxy group, a halogen atom or a halogen-substituted lower alkyl group, and R ₃ represents a lower alkyl group, a lower alkoxy group, a halogen atom, a halogen-substituted group. Lower alkyl group, halogen-substituted lower alkoxy group or group -O
Represents {C (R ₆ ) ₂ } _p- O- (connecting adjacent carbon atoms on a benzene ring to form a 5- or 6-membered ring),
中 In the formula, R ₆ represents a hydrogen atom, a lower alkyl group or a halogen atom, and p represents 1 or 2. ｝ R ₄ may be substituted with a halogen atom, a hydroxyl group, a lower alkoxy group, a lower acyloxy group or a lower alkylthio group
Represents a lower alkyl group, R ₅ represents a hydrogen atom or a lower alkyl group. However, when R ₄ is a lower alkyl group, R ₅ represents a lower alkyl group.あ る い は, or R ₄ and R ₅ together represent a carbonyl group or a thiocarbonyl group, m and n represent an integer of 0 to 4, and when m and n are 2 to 4, R ₂ and R ₃ represent They may be the same or different. And a furobenzopyran derivative represented by the formula: 2. The method according to claim 1, wherein R ₂ is a lower alkyl group or a halogen atom, R ₃ is a lower alkyl group, a lower alkoxy group or a halogen atom, and R ₄ is a lower alkyl group or a halogen-substituted lower alkyl group. A compound as described. 3. R ₂ is a lower alkyl group or a halogen atom, R ₃ is a lower alkyl group, a lower alkoxy group or a halogen atom, and R ₄ and R ₅ together form a carbonyl group or a thiocarbonyl group. Certain claim 1
A compound as described. 4. The compound according to claim 2, wherein R ₄ is a methyl group, a chloromethyl group or a bromomethyl group. 5. A herbicide comprising the furobenzopyran derivative represented by the general formula (1) according to claim 1 as an active ingredient.