6-Hydroxy-5,6-dihydrouracil compound and herbicidal composition containing thereof

A 5,6-dihydrouracil compound given by the formula [I]: wherein, R1 represents C1-C2 haloalkyl group and Q represents Q1 of the formula below, etc.: wherein, R3 is hydrogen atom or halogen atom, R15 is C3-C6 alkynyl group, etc., Z is oxygen atom, sulfur atom or NH group, and T is direct bond or methylene group, has an excellent herbicidal efficacy.

FIELD OF THE INVENTION

The present invention relates to a 5,6-dihydrouracil compound, a herbicidal composition comprising it as an active ingredient, a process for producing it and an intermediate compound for producing it.

BACKGROUND ARTS

At the present time, numerous herbicides are commercially available and they are used. There are, however, many species of weeds to be controlled and their growth extends over a long time. For this reason, requested are herbicides with higher herbicidal activity, wide herbicidal spectrum, and without causing a phytotoxicity problem to crops.

Japanese laid-open patent publication No. Hei06-092943 and U.S. Pat. No. 4,927,451 specification describe a sort of 5,6-dihydrouracil compounds below having a herbicidal activity.

However, the compounds described thereof do not always have sufficient character.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a compound having excellent character as a herbicide.

The present inventors intensively studied to find out compounds having excellent character for herbicides. As a result, they have found that the 5,6-dihydrouracil compounds given by the formula I below have excellent character for herbicides, and completed the present invention. Namely, the present invention provides the 5,6-dihydrouracil compound hereinafter, referred to as the present compound(s) given by the formula I :

wherein R 1 represents C1-C2 haloalkyl group and Q represents any group of Q1 to Q8 represented by the formulae below:

wherein Z represents oxygen atom, sulfur atom or NH group; T represents direct bond or methylene group;

R 3 represents hydrogen atom or halogen atom; R 4 represents hydrogen atom, halogen atom, cyano group, nitro group, ethynyl group or a group given by the formula:

DETAILED DESCRIPTION OF THE INVENTION

The typical examples of the present compound are the compounds given by the formula I , wherein Q is a group given by Q5, Z is oxygen atom or sulfur atom, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 4 is chlorine atom and R 6 is C1-C6 alkyl group, C3-C8 cycloalkyl group, C3-C6 alkenyl group or C3-C6 alkynyl group or (C1-C6 alkoxy)carbonyl C1-C3 alkyl group; wherein Q is a group given by Q6, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 4 is chlorine atom and R 7 is C1-C6 alkoxy group; wherein Q is a group given by Q1, Z is sulfur atom, T is direct bond, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 15 is C1-C6 alkyl group, C3-C8 cycloalkyl group, C3-C6 alkenyl group or C3-C6 alkynyl group; and wherein Q is a group given by Q1, Z is oxygen atom, T is methylene group, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 15 is C1-C6 alkyl group, C3-C8 cycloalkyl group, C3-C6 alkenyl group or C3-C6 alkynyl group. The specific examples of the present compound are the compounds given by the formula I , wherein Q is a group given by Q5, Z is oxygen atom, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 4 is chlorine atom and R 6 is 1-ethoxycarbonylethyl group; wherein Q is a group given by Q5, Z is oxygen atom, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 4 is chlorine atom and R 6 is ethoxycarbonyl group; wherein Q is a group given by Q5, Z is sulfur atom, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 4 is chlorine atom and R 6 is methoxycarbonylmethyl group; wherein Q is a group given by Q6, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 4 is chlorine atom and R 7 is isopropoxy group; wherein Q is a group given by Q5, Z is oxygen atom, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 4 is chlorine atom and R 6 is 1-methoxycarbonylethyl group; wherein Q is a group given by Q1, Z is sulfur atom, T is direct bond, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 15 is isopropyl group; wherein Q is a group given by Q5, Z is oxygen atom, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 4 is chlorine atom and R 6 is propargyl group; and wherein Q is a group given by Q1, Z is oxygen atom, T is methylene group, R 1 is trifluoromethyl group, R 3 is fluorine atom and R 15 is propargyl group.

For the present compounds, there exist optical isomers based on the presence of asymmetric carbon atom, and all of these optical isomers and mixtures thereof are included within the scope of the present invention.

In the present compounds, preferable substituents for herbicidal effect are exemplified by trifluoromethyl group as R 1 and a group given by general formula Q1 as Q. Examples of preferable substituents for Q1 include hydrogen atom and fluorine atom as R 3 , oxygen atom and sulfur atom as Z, and propargyl group and allyl group as R 15 .

The process for producing the present compounds is explained in detail below.

The present compounds can be produced by the production process below:

The production process by allowing the amide compound given by the formula II

wherein R 1 and Q have the same meanings mentioned above, to react with a cyanate salt in the presence of a protonic acid.

In the present invention, the cyanate salt includes not only cyanate salts of the narrow meaning but also isocyanate salts. Such cyanate salts of the narrow meaning are exemplified by alkali cyanates (e.g., sodium cyanate, potassium cyanate and so on). Examples of the isocyanate salt include silver isocyanate and so on.

The reaction temperature is in the range of 20 C. to 50 C., preferably 10 C. to 45 C.

The amount of the reagents to be used is usually 1 to 10 mols, preferably 1 to 2 mols of the cyanate salt based on 1 mol of the amide compound given by the formula II . The amount of the protonic acid is usually 1 mol to a large excess amount, preferably 1 to 10 mols based on 1 mol of the cyanate salt.

Examples of the protonic acid include aliphatic carboxylic acids such as acetic acid, propionic acid and butyric acid; aromatic carboxylic acids such as benzoic acid and 4-nitrobenzoic acid; sulfonic acids such as p-toluenesulfonic acid and methanesulfonic acid; and inorganic acids such as hydrochloric acid and sulfuric acid.

In the present reaction, solvents, which are inert in the present reaction condition, may be used. Examples of the solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, cyclopentane and cyclohexane; halogenated aliphatic hydrocarbons such as dichloromethane, chloroform and 1,2-dichloroethane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated aromatic hydrocarbons such as chlorobenzene and m-dichlorobenzene; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone; ethers such as diethyl ether, tert-butyl methyl ether, diethylene glycol dimethyl ether, 1,4-dioxane and tetrahydrofuran; alcohols such as methanol, ethanol, 2-propanol and propanol; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; sulfur-containing compounds such as dimethyl sulfoxide and sulfolane; nitro compounds such as nitromethane, nitroethane and 2-nitropropane; aliphatic nitriles such as acetonitrile; and mixtures thereof.

After completion of the reaction, the reaction mixture is usually poured into water and optionally neutralized. Thereafter, precipitated crystals are collected by filtration, or the reaction mixture is extracted with an organic solvent, dried and concentrated to give the objective compound. The compound can be purified by a technique such as recrystallization, column chromatography or the like.

Further, in the present process, it is also possible to allow the amide compound given by the formula II to react with cyanic acid in an inert solvent in place of allowing the amide compound given by formula II to react with a cyanate salt in the presence of a protonic acid. Cyanic acid can be obtained by the method described in J. Org. Chem., 28, p. 586 (1963) or the method allowing alkali metal cyanate to react with a protonic acid.

The amide compound given by the formula II can be prepared by the following process:

The production process by allowing an aniline compound given by the formula III :

H 2 N Q III

wherein Q has the same meaning defined above, to react with an acetate ester compound given by the formula IV :

wherein R 1 has the same meaning defined above and R 32 represents methyl group or ethyl group, in a solvent or without solvent.

The reaction temperature in said process is usually in the range of room temperature to 150 C., or room temperature to boiling point of a solvent when the solvent is utilized. Further, by-produced alcohol (methanol or ethanol) may be distilled away from the reaction mixture or a small amount of an acid or a base may be added for the purpose of speeding up the reaction.

The amount of the acetate ester compound given by the formula IV is usually at the rate of 1 to 5 mols based on 1 mol of the aniline compound given by the formula III .

Examples of the acid used for speeding up the reaction include protonic acids such as p-toluenesulfonic acid and methanesulfonic acid, and the used amount is at the rate of 0.05 to 1 mol based on 1 mol of the aniline compound given by the formula III . Examples of the base include tertiary amines such as triethylamine, tributylamine and N,N-dimethylaniline; pyridines such as pyridine and picoline; and inorganic bases such as potassium carbonate and sodium hydride, and the used amount is at the rate of 0.05 to 1 mol based on 1 mol of the aniline compound given by the formula III .

Examples of the solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, cyclopentane and cyclohexane; halogenated aliphatic hydrocarbons such as dichloromethane, chloroform and 1,2-dichloroethane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated aromatic hydrocarbons such as chlorobenzene and m-dichlorobenzene; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone and cyclohexanone; ethers such as diethyl ether, tert-butyl methyl ether, diethylene glycol dimethyl ether, 1,4-dioxane and tetrahydrofuran; amides such as N,N-dimethylformamide and N,N-dimethylacetamide: sulfur-containing compounds such as dimethyl sulfoxide and sulfolane; nitro compounds such as nitromethane, nitroethane and 2-nitropropane; aliphatic nitrites such as acetonitrile; and mixtures thereof.

After the rection is ended, usual work-up procedures described below can give the objective compound.

(1) To concentrate the reaction solution directly, wash it with water and/or an organic solvent and dry it.

(2) To pour the reaction solution into water, neutralize with aqueous saturated sodium bicarbonate and the like, extract with an organic solvent, dry and concentrate it.

(3) To pour the reaction solution into water, collect precipitated crystals by filtration and dry them.

The compound may be purified by procedures such as recrystallization, column chromatography and so on.

The aniline compounds given by the formula III are known in Japanese laid-open patent publication Nos. Sho62-221677, Sho62-158280 and so on, and can be produced according to the procedures described therein.

The process for preparing the amide compound given by the formula II may give a hydrate compound of the amide compound given by the formula II or a mixture thereof. However, the hydrate compound can be utilized for producing the present compound by the same way as the amide compound given by the formula II . The hydrate compound may have the chemical structure as follows:

wherein R 1 and Q have the same meanings as defined above.

The present compounds have excellent herbicidal activity and some of them exhibit excellent selectivity between crops and weeds. Namely, the present compounds have herbicidal activity against various troublesome weeds listed below by foliar treatment or soil treatment in upland fields.

Furthermore, some of the present compounds exhibit no significant phytotoxicity on the main crops such as corn ( Zea mays ), wheat ( Triticum aestivum ), barley ( Hordeum vulgare ), rice ( Oryza saliva ), sorghum ( Sorghum bicoloi ), soybean ( Glycine max ), cotton ( Gossypium spp. ), sugar beet ( Beta vulgaris ), peanut ( Arachis hypogaea ), sunflower ( Helianthus annuus ), and canola ( Brassica napus ); horticultural crops such as flowers and ornamental plants; and vegetable crops. The present compounds can also attain the effective control of various weeds which may cause some trouble in the no-tillage cultivation of soybean, corn, wheat and other crops. Furthermore, some of the present compounds exhibit no significant phytotoxicity on the crops.

The present compounds also have herbicidal activity against various weeds which may cause some trouble in the flooding treatment on paddy fields, such as listed below.

Furthermore, some of the present compounds exhibit no significant phytotoxicity on transplanted paddy rice.

The present compounds can also attain the control of weeds which are growing or will grow in the non-cultivated lands such as embankments; riverbanks; roadsides; railways; parks; grounds; parking places; airports; industrial facilities including factories, warehouses and so on; unused farms and unused lands in the city, and in the orchards, grasslands, lawns and forests. The present compounds also have herbicidal activity against various aquatic weeds, such as water hyacinth ( Eichhornia crassipes ), which are growing or will grow in the rivers, waterways, canals, ponds and so on.

The present compounds have the same properties as those of the herbicidal compounds described in the international patent publication WO95/34659. In the case of cultivating crops wherein tolerance is bestowed to the said crops by introducing a herbicide tolerance gene described in the said specification, the present compound can be used at larger amount than those used when ordinary crops without tolerance are cultivated, thus making it possible to control other unfavorable weeds more effectively.

When the present compound is used as the active ingredient of a herbicide, the present compound is usually mixed with solid or liquid carriers, surfactants, and other auxiliary agents to give emulsifiable concentrates, wettable powders, flowables, granules, concentrated emulsions, water-dispersible granules, or other formulations.

These formulations may comprise a compound of present invention as an active ingredient at an amount from 0.001% to 80% by weight, preferably from 0.005% to 70% by weight.

The solid carrier may include, for example, mineral fine powders such as kaolin clay, attapulgite clay, bentonite, acid clay, pyrophyllite, talc, diatomaceous earth, and calcite; organic fine powders such as walnut shell powder; water-soluble organic fine powders such as urea; inorganic salts fine powders such as ammonium sulfate; and fine powders of synthetic hydrated silicon oxide. The liquid carrier may include, for example, aromatic hydrocarbons such as methylnaphthalene, phenylxylylethane, and alkylbenzene (e.g., xylene); alcohols such as 2-propanol, ethylene glycol and 2-ethoxyethanol; esters such as dialkyl phthalate; ketones such as acetone, cyclohexanone, and isophorone; mineral oils such as machine oil; vegetable oils such as soybean oil and cottonseed oil; dimethylsulfoxide; N,N-dimethylformamide; acetonitrile; N-methylpyrrolidone; and water. As the surfactant used for emulsifying, dispersing or spreading; anionic surfactants such as alkylsulfate salts, alkylsulfonate salts, alkylarylsulfonate salts, dialkylsulfosuccinate salts and polyoxyethylenealkyl aryl ether phosphate salts and nonionic surfactants such as polyoxyethylenealkyl ethers, polyoxyethylenealkyl aryl ethers, polyoxyethylene polyoxypropylene block copolymers, sorbitan fatty acid esters and polyoxyethylene sorbitan fatty acid esters are set forth.

Ligninsulfonates, alginates, polyvinyl alcohol, gum arabic, CMC (carboxymethylcellulose), and PAP (isopropyl acid phosphate) and the like are set forth as the possible auxiliary agents, for example.

The present compound is usually formulated and then used for soil treatment before or after the emergence of weeds. The soil treatment may be include a soil surface treatment and a soil incorporation treatment. The foliar treatment may be include application over the plants and directed application in which it is applied only to weeds so as to keep off the crop plants.

Furthermore, by intermixing other herbicides, there are situations wherein an enhanced the herbicidal efficasy is confirmed. Furthermore, the present compound may be used in admixture with insecticides, acaricides, nematocides, fungicides/bactericides, plant growth regulators, fertilizers, and soil improvements.

The above compounds are disclosed in the catalog of Farm Chemicals Handbook, 1995 (published by Meister Publishing Company); AG CHEM NEW COMPOUND REVIEW, VOL. 13, 1995 (published by AG CHEM INFORMATION SERVICES); AG CHEM NEW COMPOUND REVIEW, VOL. 15, 1997 (published by AG CHEM INFORMATION SERVICES); AG CHEM NEW COMPOUND REVIEW, VOL. 16, 1998 (published by AG CHEM INFORMATION SERVICES); AG CHEM NEW COMPOUND REVIEW, VOL. 17, 1999 (published by AG CHEM INFORMATION SERVICES); and Josouzai Kenkyu Souran (published by Hakuyu-sha).

In the case when the present compound is utilized as an active ingredient of an herbicide, the application dosage may vary with the weather conditions, formulation types, application timing, application method, soil conditions, objective crops and objective weeds, but is usually applied at 0.01 g to 20,000 g, preferably 1 g to 12,000 g per hectare. When the present compound is formulated into emulsifiable concentrates, wettable powders, flowables, concentrated emulsions, water-dispersible granules, or the like, the said formulations are applied by diluting the present compound usually in 10 L to 1000 L of water (if necessary, the water may include an adjuvant such as a spreading agent) so the prescribed amount of the active ingredient can be applied to each hectare. Granules and some types of flowables are usually applied without diluting. The adjuvant which can be used herein, if necessary, may include, in addition to the surfactants as described above, polyoxyethylene resin acids (esters), ligninsulfonates, abietates, dinaphthylmethanedisulfonates, crop oil concentrates, and vegetable oils such as soybean oil, corn oil, cottonseed oil, and sunflower oil.

The present compounds can also be used as the active ingredients of harvesting aids such as defoliants and desiccants for cotton, and desiccants for potato ( Solanum tuberosum ). In these cases, the present compounds are usually formulated in the same manner as the case where they are used as the active ingredients of herbicides, and may be used alone or in admixture with other harvesting aids for foliar treatment before harvesting the crops.

EXAMPLES

Hereinafter, the present invention is explained more specifically by means of the examples, but the said examples do not limit the present invention in any way.

The production examples of the present compounds are given below, wherein the compound numbers of the present compounds are the same numbers as given in the tables 1-10.

Production Example 1

To a solution obtained by dissolving 3.56 g of Compound 1b in 14.5 mL of acetic acid, 1.04 g of sodium cyanate was added and stirred for 2.5 hours at room temperature. Then, water was added to the reaction solution, and the reaction solution was extracted with ethyl acetate. The organic layer was washed with aqueous sodium hydroxide and saturated brine successively, dried over anhydrous magnesium sulfate and concentrated to give a residue, which was subjected to column chromatography (hexane:ethyl acetete 4:1-2:1) to give 3.72 g of Compound 2b (the present compound 5-25).

Production Example 2

To a solution obtained by dissolving 2.72 g of Compound 1c in 10 mL of acetic acid, 0.79 g of potassium cyanate was added and stirred for 2 hours at room temperature. Then, to the concentrated reaction solution, water and hexane were added and allowed to stand. The precipitated crystals were collected by filtration, washed with water and hexane successesively and dried to give 2.73 g of Compound 2c (the present compound 5-68).

Production Example 3

To a solution obtained by dissolving 2.50 g of Compound 1d in 10 mL of acetic acid, 0.70 g of potassium cyanate was added and stirred for 2 hours at room temperature. Then, water was added to the concentrated reaction solution, and the reaction solution was extracted with ethyl acetate. The organic layer was washed with aqueous saturated sodium bicarbonate and saturated brine successively, dried over anhydrous magnesium sulfate and concentrated to give a residue, which was subjected to column chromatography (hexane: ethyl acetete 3:1-1:1) to give 2.68 g of Compound 2d (the present compound 5-71).

Production Example 4

To a solution obtained by dissolving 2.65 g of Compound 1e in 10 mL of acetic acid, 0.78 g of potassium cyanate was added and stirred for 10.5 hours at room temperature. Then, water was added to the concentrated reaction solution, and the reaction solution was extracted with ethyl acetate. The organic layer was washed with aqueous saturated sodium bicarbonate and saturated brine successively, dried over anhydrous magnesium sulfate and concentrated to give crystals, which were washed with hexane to give 2.61 g of Compound 2e (the present compound 6-19).

Production Example 5

To a solution obtained by dissolving 2.68 g of Compound 1f in 10 mL of acetic acid, 0.75 g of potassium cyanate was added and stirred for 3.5 hours at room temperature. Then, water was added to the concentrated reaction solution, and the reaction solution was extracted with ethyl acetate. The organic layer was washed with aqueous saturated sodium bicarbonate and saturated brine successively, dried over anhydrous magnesium sulfate and concentrated to give a residue, which was subjected to column chromatography (hexane: ethyl acetete 3:1-1:1) to give 2.84 g of Compound 2f (the present compound 5-24).

Production Example 6

To a solution obtained by dissolving 2.87 g of Compound 1g in 12 mL of acetic acid, 0.89 g of potassium cyanate was added and stirred for 4.5 hours at room temperature. Then, water was added to the concentrated reaction solution, and the reaction solution was extracted with ethyl acetate. The organic layer was washed with aqueous saturated sodium bicarbonate and saturated brine successively, dried over anhydrous magnesium sulfate and concentrated to give crystals, which were washed with hexane to give 3.14 g of Compound 2g (the present compound 3-16).

Production Example 7

To a solution obtained by dissolving 2.51 g of Compound 1h in 10 mL of acetic acid, 0.80 g of potassium cyanate was added and stirred for 3.5 hours at room temperature. Then, the reaction solution was concentrated to give crystals, which were washed with hexane to give 2.25 g of Compound 2h (the present compound 5-14).

Production Example 8

To 150 mL of toluene, 33.0 g of Compound 1a and 30.3 g of ethyl 4,4,4-trifluoroacetoacetate were added and stirred with heating under reflux for 4 hours. Then, the reaction solution was concentrated under a reduced pressure. The obtained residue was dissolved in ethyl acetate. The ethyl acetate solution was washed with conc. HCl and water successively, dried over anhydrous magnesium sulfate and concentrated under a reduced pressure to give 35.7 g of Compound 2a .

To 30 mL of acetic acid, 7.16 g of Compound 2a and 1.8 g of potassium cyanate were added and stirred at room temperature overnight (for about 12 hours). Then, the reaction solution was poured into water and extracted with ethyl acetate. The organic layer was washed with aqueous saturated sodium bicarbonate, dried over anhydrous magnesium sulfate and concentrated under a reduced pressure to give 7.17 g of Compound 3a present compound 3-3).

Some of the present compounds which are obtainable according to Production examples 1-8 are listed below, but the present invention should not be limited to them.

Formulation Example 1

Fifty parts of each of the present compounds 3-3, 3-16 and 6-5, 3 parts of calcium ligninsulfonate, 2 parts of sodium laurylsulfate, and 45 parts of synthetic hydrated silicon oxide are well pulverized and mixed to give a wettable powder for each compound.

Formulation Example 2

Ten parts of each of the present compounds 3-3, 3-16 and 6-5, 14 parts of polyoxyethylene styryl phenyl ether, 6 parts of calcium dodecylbenzene-sulfonate, 35 parts of xylene, and 35 parts of cyclohexanone are well mixed to an emulsifiable concentrate for each compound.

Formulation Example 3

Two parts of each of the present compounds 3-3, 3-16 and 6-5, 2 parts of synthetic hydrated silicon oxide, 2 parts of calcium ligninsulfonate, 30 parts of bentonite, and 64 parts of kaolin clay are well pulverized and mixed, and the mixture is well kneaded with water, followed by granulation and drying, to give a granule for each compound.

Formulation Example 4

Twenty-five parts of each of the present compounds 3-3, 3-16 and 6-5, 50 parts of 10% aqueous polyvinyl alcohol solution, and 25 parts of water are mixed and pulverized until the mean particle size reaches 5 m or smaller to give a flowable for each compound.

Formulation Example 5

Five parts of each of the present compounds 3-3, 3-16 and 6-5 is added to 40 parts of 10% aqueous polyvinyl alcohol solution, and the mixture is emulsified by dispersion with a homogenizer until the mean particle size reaches 10 m or smaller, followed by addition of 55 parts of water, to give a concentrated emulsion for each compound.

The following are Test Examples for demonstrating that the present compounds are useful as active ingredients of herbicides. The herbicidal activity and phytotoxicity are evaluated at 11 levels with indices of 0 (no effect) to 10 (died completely or their germination or growth was completely inhibited), and the herbicidal activity is judged to be excellent when ranked at 7 or more. The present compounds are designated by their compound numbers shown in Tables 1 to 10.

Test Example 1

Foliar Treatment on Upland Fields

Cylindrical plastic pots each having a diameter of 10 cm and a depth of 10 cm were filled with soil, and then seeded with ivyleaf morningglory ( Ipomoea hederacea ). The test plant was grown in a greenhouse for 14 days. Each of the present compounds 3-3, 3-16 and 6-5 was formulated into an emulsifiable concentrate according to Formulation Example 2, and then diluted in its prescribed amount with water containing a spreading agent. The dilution was uniformly sprayed over the foliage of the test plants with a sprayer at a rate of 1000 liters per hectare. After the application, the test plant was grown in the greenhouse for 12 days, and the herbicidal activity was examined. As a result, all the present compounds 3-3, 3-16 and 6-5 showed excellent activity against ivyleaf morningglory at a dosage of 20 g/are.

Test Example 2

Soil Surface Treatment on Upland Fields

Cylindrical plastic pots each having a diameter of 10 cm and a depth of 10 cm were filled with soil, and then seeded with ivyleaf morningglory ( Ipomoea hederacea ). Each of the present compounds 3-3 and 3-16 was formulated into an emulsifiable concentrate according to Formulation Example 2, and then diluted in its prescribed amount with water. The dilution was uniformly sprayed over the soil surface in the pots with a sprayer at a rate of 1000 liters per hectare. After the application, the test plant were grown in a greenhouse for 12 days, and the herbicidal activity was examined. As a result, both of the present compounds 3-3 and 3-16 showed excellent inhibition of germination against ivyleaf morningglory at a dosage of 80 g/are.