JPH08198856A - Phthalazinone derivative and agricultural and horticultural fungicide - Google Patents

Abstract

PURPOSE: To provide the subject new compound having high controlling effect against rice blast, sheath blight of rice, powdery mildew of fruit trees, vegetables and cereals, etc., and useful as an agricultural and horticultural fungicide. CONSTITUTION: This phthalazinone derivative is expressed by formula I (A is a phenyl or a nitrogen-containing 6-membered heterocyclic group having 1-3 substituents selected from halogen, lower alkyl, lower haloalkyl and lower alkoxy; X is O, S or NH; Y is H, a halogen, a lower alkyl, a lower haloalkyl or a lower alkoxy; (n) is an integer of 1-3), e.g. 2-(4,6-dimethyl-2- pyrimidinyl)-4-(benzyloxy)-1(2H)phthalazinone. The compound of formula I can be produced e.g. by reacting a compound of formula II with a benzyl halide derivative of formula III (Z is a halogen). For example, the exemplified compound of formula I is produced by using 2-(4,6-dimethyl-2-pyrimidyl)-4-hydroxy-1(2 H)phthalazinone as the compound of formula II.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel phthalazinone derivative. More specifically, it relates to a 4-substituted 1 (2H) -phthalazinone derivative represented by the following general formula (1) and an agricultural and horticultural fungicide containing the derivative as an active ingredient. Therefore, the present invention is useful in the chemical industry and the agricultural and horticultural fields, especially in the agrochemical manufacturing field.

[0002]

BACKGROUND OF THE INVENTION Several phthalazinone derivatives similar in chemical structure to the compounds of the present invention have been known so far.

For example, US Pat. No. 4,861,778
The specification describes that the phthalazinone derivative represented by the following general formula has a hyperlipidemic therapeutic activity.

[0004]

Embedded image (In the formula, R ¹ represents a lower alkyl group, a lower cycloalkyl group, a phenyl group, an alkyl group or a phenyl group substituted with a halogen atom, R ² represents a hydrogen atom or a lower alkyl group, and R ³ and R ⁴ Is a hydrogen atom, a halogen atom,
It represents a lower alkyl group or a lower alkoxy group. )

Also, 4-benzyloxy-2-isoamyl-1 (2H) -phthalazinone is known to
Royal Netherlands Chemical Society (J
individual of Royal Nealella
nd Chemical Society) Volume 70,
See pages 3 and 15 (1951).

However, it is not known that these compounds have bactericidal activity. Further, the 4-substituted 1 (2H) phthalazinone derivative represented by the following general formula (1) of the present invention is not described in the literature.

[0007]

The known phthalazinone derivatives have no bactericidal activity or a very low activity against diseases in the fields of agriculture and horticulture, as shown in the test examples below. On the other hand, various drugs have been used for important diseases of plants such as powdery mildew of plants, vegetables, cereals, downy mildew, rice blast, and rice blight. However, resistant bacteria have become a problem in any of the diseases, and there is a tendency that the drug cannot be used or its use is restricted. Therefore, in these fields, development of new fungicides having a skeleton different from that of conventional drugs is desired.
An object of the present invention is to provide a novel compound that meets these needs and an agricultural and horticultural fungicide containing the same.

[0008]

[Means for Solving the Problems] The inventors of the present invention have synthesized many compounds in order to achieve the above-mentioned object, and have diligently studied their usefulness as agricultural and horticultural fungicides. As a result, 4-substitution 1 (2 represented by the following general formula (1)
It was found that the H) phthalazinone derivative has a high activity as an agricultural and horticultural fungicide.

Therefore, the gist of the first aspect of the present invention lies in the following general formula (1):

[Chemical 4] (In the formula, A is 1 to 3 selected from a halogen atom, a lower alkyl group, a lower haloalkyl group and a lower alkoxy group.
Represents a phenyl group substituted with 4 groups or a nitrogen-containing hetero 6-membered ring, these substituents may be the same or different, X represents O, S or NH, Y represents a hydrogen atom, a halogen atom, It represents a lower alkyl group, a lower haloalkyl group or a lower alkoxy group, and n represents an integer of 1 to 3. )
In the phthalazinone derivative represented by.

The gist of the second aspect of the present invention is that it contains a 4-substituted 1 (2H) phthalazinone derivative of the general formula (1) as an active ingredient.
It is found in agricultural and horticultural fungicides.

In the compound represented by the general formula (1),
In the definitions of A and Y, the alkyl group portion of the lower alkyl group, lower alkoxy group, and lower haloalkyl group may be linear or branched. Also, the term “lower” here means
It has 1 to 6 carbon atoms.

Examples of lower alkyl groups include a methyl group,
Examples of lower haloalkyl groups include ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, sec-butyl group, n-pentyl group, isoamyl group, n-hexyl group, etc. Examples of the lower alkoxy group include a trifluoromethyl group, a difluoromethyl group, a trichloromethyl group, a dichloromethyl group, a fluoromethyl group, a chloromethyl group, an iodomethyl group, a bromomethyl group, a pentafluoroethyl group and a pentachloroethyl group. Examples of are methoxy group, ethoxy group, n
-Propoxy group, isopropoxy group, n-butoxy group,
sec-butoxy group, t-butoxy group, isobutoxy group, n-pentyloxy group, isopentyloxy group, n
-Hexyloxy group, isohexyloxy group and the like.

Examples of the halogen atom include chlorine atom, fluorine atom, iodine atom and bromine atom.

Further, in the definition of A, nitrogen-containing hetero 6
Examples of the member ring include a pyridyl group, a pyrimidinyl group and a triazinyl group.

Further, when the phenyl group defined by A and the nitrogen-containing hetero 6-membered ring have 1 to 3 substituents as described above and have 2 or more substituents, those substituents are mutually They may be the same or different.

Specific examples of the compound of the present invention represented by the general formula (1) are shown in Tables 1 and 2.

Compound No. Is also referred to in the following examples and test examples.

[0018]

[Table 1]

[0019]

[Table 2]

The compound of the general formula (1) of the present invention is a novel compound. And the compound of this general formula (1) acts as an active ingredient of an agricultural and horticultural fungicide.

[0021]

EXAMPLES Method for Producing Compound of the Present Invention The compound of the general formula (1) according to the present invention can be produced by either method (A) or method (B).

First, the method (A) will be specifically described.

General formula (3)

Embedded image (In the formula, A represents the same meaning as described above.) The compound of the formula (3) represented by the general formula (4)

[Chemical 6] (In the formula, Y and n have the same meanings as described above, and Z represents a halogen atom.) By reacting with a benzyl halide derivative represented by the general formula (1)

[Chemical 7] (In the formula, A, Y and n have the same meanings as described above, and X represents O.), and the compound of the present invention is obtained.

The following formula (3) which is a starting material in the method (A)

Embedded image (Wherein A represents the same meaning as described above), the compound of formula (3) is a compound of Journal of Chemical Society.
Society) p. 852-p. 855 (1955)
Method, that is, the general formula (2)

[Chemical 9] (In the formula, A has the same meaning as described above.) And phthalazine anhydride can be produced by cyclocondensation in a solvent with an acid or an alkali as a catalyst.

Specific examples of the compound of the formula (3) include 2-
(2-chlorophenyl) -4-hydroxy-1 (2H)
Phthalazinone <formula (3) -1>, 2- (3-chlorophenyl) -4-hydroxy-1 (2H) phthalazinone <formula (3) -2>, 2- (4-chlorophenyl) -4-hydroxy-1 ( 2H) phthalazinone <formula (3) -3>, 2
-(4-chlorophenyl) -4-hydroxy-1 (2
H) phthalazinone <formula (3) -4>, 2- (3-trifluoromethylphenyl) -4-hydroxy-1 (2H)
Phthalazinone <formula (3) -5>, 2- (3,5-dichlorophenyl) -4-hydroxy-1 (2H) phthalazinone <formula (3) -6>, 2- (4,6-dimethyl 2-pyrimidyl) -4-Hydroxy-1 (2H) phthalazinone <Formula (3) -7>, 2- (5-chloro 6-ethyl 3
-Pyrimidyl) -4-hydroxy-1 (2H) phthalazinone <formula (3) -8>, 2- (4,6-dimethoxy 2
-Triazyl) -4-hydroxy-1 (2H) phthalazinone <formula (3) -9>, 2- (3-methylphenyl)-
4-hydroxy-1 (2H) phthalazinone <formula (3)-
10>, 2- (4-methoxyphenyl) -4-hydroxy-1 (2H) phthalazinone <formula (3) -11>, 2-
(2,4-dichlorophenyl) -4-hydroxy-1
(2H) phthalazinone <formula (3) -12>, 2- (3,
5-dichloro 2-pyridyl) -4-hydroxy-1
(2H) phthalazinone <formula (3) -13>, 2- (4
6-dimethoxy 2-pyrimidyl) -4-hydroxy-
1 (2H) phthalazinone <formula (3) -14>, 2-
(4,6-Dimethyl 2-pyrimidyl) -4-hydroxy-1 (2H) phthalazinone <Formula (3) -15>, 2-
(5-trifluoromethyl 2-pyridyl) -4-hydroxy-1 (2H) phthalazinone <formula (3) -16>,
Is mentioned.

Formulas (3) -1 to (3) -16, which are compound numbers of specific examples of the compound of formula (3) as a raw material, are represented by formulas (1) -1 to (1)-of the target compound. 16 respectively. Therefore, for example, the compound of formula (3), which is a raw material and corresponds to “formula (1) -1” of the target compound, is meant to be “formula (3) -1”.

Next, a specific method for producing the compound of formula (1) according to method (A) will be described in detail.

In the method (A), the step of reacting the compound of the formula (3) with the compound of the formula (4) uses an equivalent amount of each reaction component, and 1 equivalent to 2 equivalents of the deionized compound to the compound of the formula (3) are used. The reaction is carried out in a suitable organic solvent in the presence of a hydrogen halide agent.

The reaction temperature is a temperature close to the boiling point of the organic solvent,
The temperature is preferably 20 to 80 ° C., and the reaction is carried out by stirring the reaction mixture for 1 to 3 hours.

As the dehydrohalogenating agent, organic bases such as triethylamine, pyridine and N, N, -diethylaniline, and inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate and potassium carbonate are used. it can.

As the organic solvent, benzene, toluene,
Hydrocarbons such as xylene, halogenated hydrocarbons such as chloroform, dichloromethane, chlorobenzene, ethers such as ethyl ether, dioxane and tetrahydrofuran, nitriles such as acetonitrile and propionitrile, amides such as dimethylformamide and dimethylacetamide. And dimethyl sulfoxide can be used.

After completion of the reaction, water and an organic solvent such as benzene, toluene and chloroform are added to the reaction liquid to separate the liquid,
After dehydration with anhydrous sodium sulfate, anhydrous magnesium sulfate, etc., a usual treatment such as distilling off the solvent is carried out, and if necessary, purification may be carried out by operations such as chromatography and recrystallization.

Next, the method (B) will be specifically described.

[0034]

Embedded image General formula (3) (In the formula, A has the same meaning as described above.) The compound of the formula (3) represented by the formula (3) is reacted with a halogenating agent to replace the OH group of the compound of the formula (3) with halogen.

[Chemical 11] (In the formula, X'represents a halogen atom.) The compound of formula (6) represented by the formula (6) is produced in the reaction solution as an intermediate, and subsequently, the compound of the general formula (5)

[Chemical 12] (In the formula, X represents S or NH, and Y and n have the same meanings as described above.) By reacting with a benzylamine derivative represented by the general formula (1)

[Chemical 13] (In the formula, A, Y and n have the same meanings as described above, and X represents S or NH.) A compound of formula (1) is obtained.

In the method (B), the compound of the formula (3) is used as a starting material, halogenated to obtain the compound of the formula (6), and subsequently reacted with the compound of the formula (5). The compound is reacted in a solvent amount of halogenating agent.

As the halogenating agent, sulfuryl chloride,
Phosphorus oxychloride, phosphorus oxybromide, phosphorus pentachloride and the like can be used.

The reaction temperature is close to the boiling point of the halogenating agent, preferably 60 to 100 ° C., and the reaction is carried out by stirring for 1 to 3 hours. Then, the halogenating agent is distilled off to obtain an oily substance. When X in the compound of the formula (5) represents NH, 1 to 10 equivalents of the compound of the formula (5) is added to the oily substance and reacted. In this reaction, when the amount of the compound of the formula (5) used is less than 2 equivalents, the reaction is carried out using 1 to 2 equivalents of the dehydrohalogenating agent and a suitable organic solvent.

When X of the compound of the formula (5) represents S, the oily substance obtained by the reaction of the compound of the formula (3) and the compound of the formula (5) is 1 to 1% of the compound of the formula (3) used. 2 equivalents of the compound of formula (5) are added and reacted with 1 to 2 equivalents of the dehydrohalogenating agent in a suitable solvent.

The reaction temperature is a temperature close to the boiling point of the organic solvent,
The temperature is preferably 80 to 120 ° C., and the reaction mixture is adjusted to 1 to 5
The reaction is carried out with stirring over time.

As the dehydrohalogenating agent, organic bases such as triethylamine, pyridine and N, N, -diethylaniline, and inorganic bases such as sodium carbonate, sodium hydrogen carbonate and potassium carbonate can be used.

Examples of the organic solvent include hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as chlorobenzene, ethers such as dioxane and tetrahydrofuran, nitriles such as acetonitrile and propionitrile, dimethylformamide and dimethylacetamide. Amides such as and dimethyl sulfoxide can be used.

After completion of the reaction, purification may be carried out in the same manner as in the method (A).

Example 1 2- (4,6-dimethyl 2-
Pyrimidinyl) -4- (benzyloxy) -1 (2H)
Production of phthalazinone (Compound No. (1) -7) <Method (A)> 2- (4,6-dimethyl 2-pyrimidyl) -4- (hydroxy) -1 was placed in a four-necked flask having a capacity of 500 ml.
(2H) phthalazinone 26.8 g, benzyl chloride 12.7 g (1 equivalent), potassium carbonate 13.8 g
(1 equivalent) and dimethylformamide (250 ml) were added, and the mixture was heated with stirring and kept at 75 ° C. for reaction. After cooling, the reaction solution was poured into water and extracted with chloroform, the organic layer was washed with water and dried over anhydrous sodium sulfate.
Then, the solvent was distilled off under reduced pressure, and silica gel column chromatography (developing solvent: toluene-acetone = 3
After purification with 0: 1) and recrystallization from a mixed solvent of n-hexane-acetone, 26.1 g of the title compound (yield 73
%) As brown crystals (mp 138 to 139 ° C.).

Example 2 2- (3-methylphenyl)-
4- (4-trifluoromethylbenzylamino) -1
Production of (2H) phthalazinone (Compound No. (1) -10) <Method (B)> 2- (3-methylphenyl) -4- (hydroxy) -1 (2H) was added to a 500 ml four-necked flask. 200 ml of phosphorus oxychloride was added to 25.2 g of phthalazinone, and the mixture was stirred at 100 ° C. for 4 hours. Then, phosphorus oxychloride was distilled off under reduced pressure, 175 g (10 equivalents) of 4-trifluoromethylbenzylamine was added, and the mixture was stirred at 150 ° C. for 17 hours. After completion of the reaction, the reaction mixture was put into water and extracted with chloroform, the organic layer was washed with water and dried over anhydrous sodium sulfate. Then, the solvent was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent: toluene-ethyl acetate = 50: 1) to give 16.3 g (yield 40%) of the title compound as a brown oil (n ²³ _D 1.
6407).

[0045]

EXAMPLES Method for Formulating Agricultural and Horticultural Fungicide In addition, the agricultural and horticultural bactericidal agent of the second invention can be used by formulating the compound of the general formula (1) by a conventional formulation. That is, the compound of the general formula (1) and a suitable carrier and auxiliary agent such as a surfactant, a binder, a stabilizer and the like can be blended to give a formulation generally used as a pesticide formulation. For example, powder, coarse powder,
DL (driftless type) powder, flow dust, fine granule, fine granule, granule, wettable powder, sol (flowable),
It can be formulated into hydrated granules, emulsions and oils.

The dosage forms that can be formulated are not limited to those listed here.

The addition amount of the compound of the present invention can be appropriately changed depending on the dosage form of the preparation and the method of use, and is generally 0.1 to 0.1%.
It is desirable to use in the formulation in the range of 90% by weight.

The method of using the agricultural / horticultural germicide of the present invention is generally as follows. That is, in the case of a wettable powder, an emulsion, a liquid agent, a sol agent (flowable agent) and an oil agent, the active ingredient is generally diluted in an amount of 50 to 2000 times with water.
The solution is adjusted to a concentration of 0000 ppm. Then, the diluted solution is sprayed onto the foliage at the disease occurrence site of the plant in an amount of 50 to 300 liters, usually 100 to 200 liters, per 10 ares.

Further, liquid solutions, emulsions and sol agents (flowable agents) are not diluted with water and remain as a concentrated solution or with water.
Dilute to within 0 times and use it as a microspraying agent (L
50 per 10 are as V spray and ULV spray)
~ 300ml is sprayed using a helicopter.

Further, powder, coarse powder, DL powder, flow dust, fine granule, fine granule and granule are 2 to 10 ares.
5 kg (about 5 to 500 g as the amount of active ingredient) is applied to the foliage of the disease occurrence site of the plant, the soil surface, the soil or the water surface.

The method of formulating the compound of the present invention represented by the general formula (1) as an agricultural and horticultural fungicide is described in Example 3 below.
~ 7.

Example 3 (Dust) Compound No. 2 parts of the compound of (1) -1, 1 part of PAP (physical property improver) and 97 parts of clay are uniformly mixed and ground to obtain a dust containing 2% of the active ingredient.

Compound No. Dusts can be similarly obtained by using the compounds shown in Table 1 and Table 2 instead of (1) -1.

Example 4 (Wettable powder) Compound No. (1) -20 parts of the compound, 3 parts of potassium alkylbenzene sulfonate, 3 parts of polyoxyethylene nonylphenyl ether and 72 parts of clay were uniformly mixed and pulverized to obtain a wettable powder containing 20% of the active ingredient. obtain.

Compound No. A wettable powder can be similarly obtained by using the compounds described in Table 1 and Table 2 instead of (1) -7.

Example 5 (Emulsion) Compound No. 30 parts of the compound of (1) -4, 40 parts of methyl ethyl ketone and 30 parts of polyoxyethylene nonylphenyl ether are mixed and dissolved to give 30% of the active ingredient.
Obtain the containing emulsion.

Compound No. Emulsions can be similarly obtained by using the compounds shown in Tables 1 and 2 in place of (1) -4.

Example 6 (sol agent) Compound No. (1) -3 compound 40 parts, lauryl sulfate 2 parts, sodium alkylnaphthalene sulfonate 2
Parts, acetoxypropyl cellulose 1 part and water 55 parts uniformly mixed to obtain a sol containing 40% of the active ingredient.

Compound No. Sol compounds can be similarly obtained by using the compounds shown in Tables 1 and 2 in place of (1) -3.

Example 7 (Granule) Compound No. (1) -10 parts of the compound, 10 parts of lauryl sulfate, 5 parts of calcium lignin sulfonate,
30 parts of bentonite and 54 parts of clay are mixed with 15 parts of water and kneaded by a kneader, then granulated by a granulator and dried by a fluid dryer to obtain a granule containing 10% of an active ingredient.

Compound No. Instead of (1) -10, Table 1
Granules can be obtained in the same manner using the compounds shown in Table 2 and Table 2.

[0062]

INDUSTRIAL APPLICABILITY The compound of the present invention shows a high control effect against rice blast, rice blight, and powdery mildew of fruit trees, vegetables and cereals, which are important diseases of plants. It is useful as an agent.

Specific examples of the usefulness of the compound of the present invention are shown in Test Examples 1 to 3.

Test Example 1 Rice Blast Control Effect Test Prepared according to Example 4 on the third leaf stage seedlings of paddy rice (cultivar: Asahi) cultivated in a greenhouse in a clay pot with a diameter of 9 cm. 10 ml of a dilute solution of the wettable powder having a predetermined concentration was sprayed per pot. In advance, rice blast fungus ( Pyricura
lia oryzae: adjusted to Pyricularia conidia exhibition oryzae) Chakuzai (polyoxyethylene 5 × 10 ⁵ spores Spore concentration at 50ppm aqueous alkyl ether) (number) / ml, which the foliage of the rice Spray inoculated. After keeping it in an inoculation box at 24 ° C. and 100% humidity overnight, it was transferred to a greenhouse at 24 ° C. to promote disease onset. Five days after the inoculation, the number of rice blast lesions per leaf of the third leaf was examined, and the control value (%) was calculated by the following formula.

This test is carried out in a system of 3 pots per concentration of chemical solution,
The average control value (%) was calculated and converted into the evaluation value of the control effect according to the following criteria. In addition, phytotoxicity to rice was investigated according to the following criteria. The results are shown in Table 3.

The evaluation value of the controlling effect and the investigation index of the chemical damage were similarly used in the following Test Examples 2 to 4.

[0067]

[Equation 1]

[0068]

[0069]

[Table 3]

[0070]

Embedded image Comparative compound A (Compounds described in US Pat. No. 4,861,778)

[0071]

Embedded image Comparative compound B [Journal of Royal Netherlands Chemical Society (Journal of Royal
Netherland ChemicalSoci
ety) Volume 70, page 3, page 15 (1951) described compound]

Test Example 2 Test for controlling rice blight disease 6 Soil cultivation was carried out in a greenhouse in a plastic pot with a diameter of 9 cm.
-10 ml of a predetermined concentration diluting solution of a wettable powder prepared according to Example 4 was added to rice seedlings (variety: Asahi) at the 7th leaf stage.
Sprayed. One day after the application, rice root blight fungus ( Rizoctonia solani : Rhizoctonia solani ) cultivated in a rice straw medium in advance was placed at the origin of the rice as an inoculum source. Then, it was allowed to stand in a greenhouse at 24 ° C. and a humidity of 100% for 5 days to cause rice blight. Five days after the inoculation, the lesion length of the diseased leaf sheath was measured, and the control value (%) was calculated by the following formula.

This test was carried out in a system of 3 pots per concentration of chemical solution,
The average control value (%) was calculated and converted into an evaluation value of the control effect. In addition, the phytotoxicity to rice was investigated and displayed according to the same criteria as in Test Example 1. The results are shown in Table 4.

[0074]

[Equation 2]

[0075]

[Table 4]

Test Example 3 Barley Powdery Mildew Control Effect Test According to Example 4, the first leaf stage seedlings of barley (variety: Azuma Golden) cultivated in a greenhouse in a clay pot with a diameter of 9 cm were cultivated. 10 ml of the diluted wettable powder having a predetermined concentration was sprayed per pot. After left overnight, barley powdery mildew ( Eris) pre-formed on barley leaf
iphe graminis : Erysiphe graminis ) conidiospores with a 50 ppm aqueous solution of a spreading agent (polyoxyethylene alkyl ether) to give a spore concentration of 5 × 10.
^The number was adjusted to ⁵ spores (ml) / ml, and this was spray-inoculated onto barley foliage. Then, after keeping it in an inoculation box at 20 ° C. and 100% humidity overnight, it was transferred to a greenhouse at 20 ° C. to promote disease onset. Seven days after the inoculation, the number of barley powdery mildew lesions was examined, and the control value (%) was calculated by the following formula.

This test was carried out in a system of 3 pots per concentration of chemical solution,
The average control value (%) was calculated and converted into the evaluation value of the control effect.

Further, phytotoxicity against barley was investigated and displayed according to the same criteria as in Test Example 1. The results are shown in Table 5.

[0079]

(Equation 3)

[0080]

[Table 5]

Front page continuation (72) Inventor Seiichi Kutsuma 3-21-13 Sabudai, Sagamihara-shi, Kanagawa Laplace Fujishin 102 (72) Inventor Yasushi Noshiro 2385 Toda, Atsugi-shi, Kanagawa Kitakogaku Dormitory

Claims (2)

[Claims] 1. A general formula: (In the formula, A is 1 to 3 selected from a halogen atom, a lower alkyl group, a lower haloalkyl group and a lower alkoxy group.
Represents a phenyl group substituted with 4 groups or a nitrogen-containing hetero 6-membered ring, these substituents may be the same or different, X represents O, S or NH, Y represents a hydrogen atom, a halogen atom, It represents a lower alkyl group, a lower haloalkyl group or a lower alkoxy group, and n represents an integer of 1 to 3. )
A phthalazinone derivative represented by. 2. A general formula: (In the formula, A is 1 to 3 selected from a halogen atom, a lower alkyl group, a lower haloalkyl group and a lower alkoxy group.
Represents a phenyl group substituted with 4 groups or a nitrogen-containing hetero 6-membered ring, these substituents may be the same or different, X represents O, S or NH, Y represents a hydrogen atom, a halogen atom, It represents a lower alkyl group, a lower haloalkyl group or a lower alkoxy group, and n represents an integer of 1 to 3. )
A fungicide for agricultural and horticultural use, comprising a phthalazinone derivative represented by as an active ingredient.