JPH08291110A - Salicylic acid derivative, its production and agricultural and horticultural fungicide - Google Patents

Abstract

PURPOSE: To obtain a salicylic acid derivative having low toxicity and high safety to man and beast and exhibiting excellent controlling effect on wide variety of plant blights and obtain an agricultural and horticultural fungicide containing the derivative. CONSTITUTION: This salicylic acid derivative is expressed by formula I (X is a lower alkyl, a lower alkoxy, hydroxy, a halogen, nitro, cyano, etc.; Y is a lower alkyl or a halogen; (n) is an integer of 0-5; (m) is an integer of 0-3; R<1> is H or a lower alkyl) or its salt, e.g. 2-(3-chlorobenzyloxy)-6-hydroxybenzoic acid. The compound of formula I can be produced e.g. by reacting a 2,6- dihydroxybenzoic acid derivative of formula II (R is a lower alkyl) with a substituted benzyl halide of formula III (Z is a halogen) and optionally hydrolyzing the reaction product. The agricultural and horticultural fungicide contains 0.1-95wt.%, preferably 0.5-90wt.%, more preferably 2-70wt.% of the compound of formula I as an active component.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a salicylic acid derivative, a method for producing the same, and an agricultural and horticultural fungicide containing the salicylic acid derivative as an active ingredient.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 49-7214 discloses 2- (3,4-dimethylbenzyl) oxy-6-hydroxybenzoic acid. Chem.Phram.Bull., 27 (6), 1468-72 (1979)
Describes 2-benzyloxy-6-hydroxybenzoic acid. J. Am. Chem. Soc., 94 (19), 6834-43
(1972) describes 2-benzyloxy-3,5-dibromo-4-methyl-6-hydroxybenzoic acid methyl ester. 2 in J. Med. Chem., 36 (18), 2676-88 (1993)
-Benzyloxy-6-hydroxybenzoic acid methyl ester is described. Japanese Patent Laid-Open No. 5-70400 discloses 2-
(2,5-Dimethoxybenzyl) oxy-6-hydroxybenzoic acid methyl ester is described. However,
Nothing about bactericidal activity is described in these documents.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have developed a fungicide for agricultural and horticultural use which has low toxicity to humans and animals, high safety in handling, and excellent control effect against a wide range of plant diseases. In order to do so, it was an object to synthesize the salicylic acid derivative of the formula (I · II) of Chemical formula 4 and its salt and to clarify their bactericidal properties. Therefore, an object of the present invention is to provide a salicylic acid derivative, a method for producing the same, and an agricultural / horticultural fungicide. (In the formula,
X is a lower alkyl group, a lower alkoxy group, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a lower haloalkyl group,
It represents a phenoxy group or a dimethylamino group. Y represents a lower alkyl group or a halogen atom. n represents an integer of 0 to 5. When n is 2 or more, X may be the same or different. m represents an integer of 0 to 3.
When m is 2 or more, Y may be the same or different. R ¹ represents a hydrogen atom or a lower alkyl group)

[Chemical 4]

[0004]

The present invention has the following structural features. The first invention relates to an agricultural and horticultural fungicide containing the salicylic acid derivative of the formula (I · II) of Chemical formula 5 or a salt thereof as an active ingredient. (In the formula, X is a lower alkyl group,
Lower alkoxy group, hydroxyl group, halogen atom, nitro group,
A cyano group, a lower haloalkyl group, a phenoxy group, or
Represents a dimethylamino group. Y represents a lower alkyl group or a halogen atom. n represents an integer of 0 to 5. n is 2
In the above cases, X may be the same or different. m represents an integer of 0 to 3. When m is 2 or more, Y may be the same or different. R ¹ represents a hydrogen atom or a lower alkyl group)

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A second aspect of the invention is to synthesize a salicylate ester of formula (II) by reacting a 2,6-dihydroxybenzoic acid derivative of formula (III) of formula 6 with a substituted benzyl halide of formula (IV). And then hydrolyzing the ester moiety, to a method for producing a substituted salicylic acid of formula (I). (In the formula, X represents a lower alkyl group, a lower alkoxy group, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a lower haloalkyl group, a phenoxy group or a dimethylamino group. Y represents a lower alkyl group or a halogen atom.
n represents an integer of 0 to 5. When n is 2 or more,
X may be the same or different. m is from 0
Represents an integer of 3. When m is 2 or more, Y may be the same or different. R represents a lower alkyl group. Z represents a halogen atom)

[Chemical 6]

The third invention relates to a salicylic acid derivative of the above formula (I · II) or a salt thereof. [However, 2-benzyloxy-6-hydroxybenzoic acid, 2- (3,4-dimethylbenzyl) oxy-6-hydroxybenzoic acid, 2-benzyloxy-3,5-dibromo-4-methyl-6-hydroxy Excludes methyl benzoate, 2-benzyloxy-6-hydroxybenzoic acid methyl ester, and 2- (2,5-dimethoxybenzyl) oxy-6-hydroxybenzoic acid methyl ester]

Hereinafter, the present invention will be described in detail. Among the substituents of the salicylic acid derivative (I · II) of the present invention, the substituents represented by the general concept include the following preferable substituents.
X is a lower alkyl group, a methyl group, 1,1-dimethylethyl group, a lower alkoxy group is a methoxy group, (1-methylethyl) oxy group, a halogen atom is a fluorine atom, a chlorine atom, a bromine atom, an iodine atom. , A lower haloalkyl group, a trifluoromethyl group. In the lower alkyl group of Y,
Methyl and halogen atoms are chlorine atoms. The preferred range of integer n is 0 to 2. The preferred range of integer m is 0 to 1. The lower alkyl group for R ¹ includes a methyl group, an ethyl group,
1-methylethyl group. The salicylic acid derivative (I / II) salt is a salt containing sodium, potassium, copper or 1-methylethylamine. In the lower alkyl group, lower alkoxy group and lower haloalkyl group, an alkyl group having 1 to 4 carbon atoms is preferable. The lower haloalkyl group means that at least one hydrogen atom of the lower alkyl group is substituted with a halogen atom, preferably a fluorine atom.

Next, Table 1 in Table 1 shows specific examples of salicylic acid derivatives (I · II).

[Table 1] ^A) : 3-CH in compound (I-2)₃ Indicates a methyl group bonded to the 3-position. Similarly, 3-OC in compound (I-45)₆H_Five Indicates a phenoxy group bonded to the 3-position. 2,3- (CH in compound (I-4)₃)₂Indicates that a methyl group is bonded to the 2- and 3-positions. That is, the number before the hyphen (-) indicates the bonding position, the number after the hyphen (-) indicates the substituent, and the number when there are two or more bonding positions. H in the compound (I-1) indicates that it is unsubstituted. This rule is also used for the substituent Yn.

Examples of the diluent used in the production method of the present invention include the following. water. Organic acids such as formic acid, acetic acid and propionic acid. Hydrocarbons such as benzene, toluene, xylene, petroleum ether, pentane, hexane and heptane. Halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride. Alcohols such as methanol, ethanol, isopropanol and t-butanol. Ethers such as diethyl ether, dimethoxyethane, diisopropyl ether, tetrahydrofuran, diglyme and dioxane. In addition, carbon disulfide, acetonitrile, acetone, ethyl acetate, acetic anhydride, pyridine, dimethylformamide, dimethylacetamide, 1-methyl-2-pyrrolidinone, dimethyl sulfoxide, hexamethylphosphoric amide and the like.

The following can be exemplified as the base. Alkali metal carbonates such as sodium carbonate, sodium hydrogen carbonate, potassium carbonate and potassium hydrogen carbonate. Carbonates of alkaline earth metals such as calcium carbonate and barium carbonate. Alkali metal carboxylates such as sodium acetate, potassium acetate and sodium propionate. Sodium hydroxide,
Alkali metal hydroxides such as potassium hydroxide. Oxides of alkaline earth metals such as magnesium oxide and calcium oxide. Alkali metals such as lithium, sodium and potassium, alkaline earth metals such as magnesium. Alkali metal alkoxides such as sodium methoxide, sodium ethoxide and potassium t-butoxide. Alkali metal hydrogen compounds such as sodium hydride and potassium hydride. Organometallic compounds of alkali metals such as methyllithium, ethyllithium, n-butyllithium and phenyllithium. Organic Grignard reagents such as methylmagnesium iodide, ethylmagnesium bromide and n-butylmagnesium bromide. Organometallic compounds of alkali metals and organocopper compounds that can be prepared from Grignard reagents and copper (I) salts. Alkali metal amides such as lithium diisopropylamide. Ammonium hydroxides such as aqueous ammonia, benzyltrimethylammonium hydroxide, and tetramethylammonium hydroxide. Organic amines such as methylamine, ethylamine, n-propylamine, benzylamine, ethanolamine, dimethylamine, benzylmethylamine, dibenzylamine, triethylamine, triethanolamine and pyridine.

As salts of the first transition element used in the production of the metal complex salt of salicylic acid derivative (I · II), acetate, hydrochloride, nitrate, sulfate, (the latter three kinds of salts, hydrochloride and nitrate) , When using a sulfate, it is advantageous to use an alkali metal acetate, carbonate or hydroxide simultaneously. Examples of the acid include inorganic acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, perchloric acid, nitric acid and sulfuric acid, and organic acids such as formic acid, acetic acid, butyric acid and p-toluenesulfonic acid. .

The precursor of substituted salicylic acid (I), salicylic acid ester (II), is preferably a 2,6-dihydroxybenzoic acid derivative (III) and substituted benzyl halide (IV) in the presence of a base in a diluent. Can be manufactured. To carry out the production method of the present invention, for example, a 2,6-dihydroxybenzoic acid derivative (III) dissolved in the above-mentioned diluent is added to a substituted benzyl in the presence of the above-mentioned base, if necessary. Halide (I
V) is added in an amount of 0.5 to 1.5 equivalents, or conversely, the substituted benzyl halide (IV) is dissolved in a diluent, and the 2,6-dihydroxybenzoic acid derivative (III) and a base are preferably added and reacted. The reaction temperature at this time may be any temperature from the freezing point to the boiling point of the diluent as a solvent, but in practice it is preferable to carry out the reaction at a temperature in the range of 0 to 100 ° C. The reaction time is in the range of 1 to 10 hours, and it is desirable to carry out the reaction with stirring. After the completion of the above reaction, the reaction mixture obtained by the reaction was cooled, then extracted with an organic solvent such as ethyl acetate, chloroform, benzene and the like to separate an organic layer, and then the organic layer was washed with water and dried, The solvent is distilled off under reduced pressure, and the resulting residue is subjected to purification treatment to obtain salicylic acid ester (II). The purification treatment can be performed by subjecting it to recrystallization, silica gel column chromatography or the like.

Hydrolysis of the ester portion of salicylic acid ester (II) can be carried out as follows. Salicylic acid ester (II) and alkali metal hydroxide are added to hydrous alcohol and refluxed at 20 to 100 ° C. or 20 ° C. to the reflux point of the solvent for 1 to 20 hours. After the reaction, the reaction mixture is acidified and the precipitate is collected by filtration, or the solvent is distilled off, water is added to the residue and the mixture is well stirred, and then the insoluble matter is collected by filtration. Then, the residue was recrystallized to give the substituted salicylic acid (I).
Can be obtained.

Since the substituted salicylic acid (I) thus obtained has an acidic proton, it can form a salt in which the hydrogen atom is replaced with a suitable cation. These salts are
Generally, a metal salt, especially an alkali metal salt, an alkaline earth metal salt, or a complex salt with a first transition element containing copper, or in some cases, an ammonium salt, an alkylated ammonium salt or an organic amine salt, and preferably Is
In a solvent such as water, methanol or acetone
It can be produced at a temperature of 20-100 ° C.

Next, the usefulness of the salicylic acid derivative of the above formula (I · II) according to the present invention as an active ingredient of an agricultural and horticultural fungicide will be described. Salicylic acid derivative of the present invention (I
I) exhibits a controlling effect against the following wide range of plant diseases. Rice blast (Pyricularia oryzae), rice sesame leaf blight fungus (Cochliobolus miyabeanus), rice sprouting seedling fungus (G
ibberella fujikuroi), Helminthosp
orium sigmoideum), Rhizoctonia solan
i), Gray mold disease (Botrytis cinerea) that causes various crops,
Sclerotinia sclerotiorum, watermelon vine (Fusarium oxysporum f.sp.niveum), cucumber vine (Fusarium oxysporum f.sp.cucumerinum), cucumber anthracnose (Colletotrichum lagenarium), sugar beet brown spot (Cercospora beticola), soybean purpura (Cercospoa beticola)
ra kikuchii), peach sterilizer (Sclerotinia cinerea),
Apple spot leaf spot fungus (Alternaria alternata (mali)), pear black spot fungus (Alternaria alternata (kikuchiana)), grape late rot fungus (Glomerella cingulata), cucumber downy mildew (P
seudoperonosora cubensis), tomato late blight (Phytophthra
infestans), Phytophthora capsic
i), Pythium aphanidermatum, etc.

In order to apply the salicylic acid derivative (I / II) as a fungicide for agricultural and horticultural use as described above, the compound can be used as it is, but usually, together with a formulation auxiliary agent,
It is used by formulating it into various forms such as powder, wettable powder, granules and emulsion. At this time, the formulation contains one or more salicylic acid derivatives (I · II) in an amount of 0.1 to 95% by weight, preferably 0.5 to 90% by weight, more preferably 2 to 70% by weight. To be formulated. Examples of carriers, diluents, and surfactants used as formulation aids include solid carriers such as talc, kaolin, bentonite, diatomaceous earth, white carbon, and clay. Liquid diluents include water, xylene, toluene, chlorobenzene, cyclohexane, cyclohexanone, dimethylsulfoxide, dimethylformamide, alcohol and the like. The surfactant should be used properly depending on its effect, and as an emulsifier, polyoxyethylene alkylaryl ether, polyoxyethylene sorbitan monolaurate, etc. As a dispersant, lignin sulfonate, dibutyl naphthalene sulfonate, etc.,
Examples of the wetting agent include alkyl sulfonates and alkyl phenyl sulfonates. The above-mentioned preparations include those to be used as they are and those to be used after being diluted to a predetermined concentration with a diluent such as water. The concentration of the compound of the present invention when diluted and used is preferably in the range of 0.001 to 1.0%. The amount of the compound of the present invention used is 20 to 5000 per 1 ha of agricultural and horticultural land such as fields, rice fields, orchards and greenhouses.
g, more preferably 50 to 1000 g. The concentrations and amounts of these substances used vary depending on the dosage form, the time of use, the method of use, the place of use, the target crop, etc., and therefore it is of course possible to increase or decrease without sticking to the above range. In addition, the compounds of the present invention are other active ingredients such as fungicides,
It can also be used in combination with insecticides, acaricides and herbicides. Since this compound contains a carboxylic acid, it can be used in the form of inorganic salts, organic salts, metal complex salts, or the like.

[0017]

EXAMPLES The present invention will be specifically described with reference to Production Examples, Reference Production Examples, Formulation Examples, and Test Examples. The present invention is not limited to the following production examples, formulation examples and test examples as long as the gist thereof is not exceeded. Production Example 1 2-Benzyloxy-6-hydroxybenzoic acid (I-1)
Preparation of 20 To 25 ml of anhydrous dimethylformamide, 120 mg of sodium hydride (60% oily sodium hydride washed with anhydrous hexane) was added with stirring under a nitrogen atmosphere, and then 2,6-dihydroxybenzoic acid methyl ester was added. 0.84 g was added, and the mixture was stirred under ice cooling until foaming stopped. Benzyl chloride 0.76 was added to the obtained solution.
A solution of g in 25 ml of anhydrous dimethylformamide was added dropwise, and the mixture was stirred at a temperature of 70 ° C. for 10 hours. The obtained reaction mixture was allowed to cool, then poured into ice water and extracted with ethyl acetate to obtain an organic layer. The organic layer was washed with water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. did. The obtained residue was purified by silica gel column chromatography to obtain 0.99 g of salicylic acid ester (II-1) of the title compound. The obtained salicylic acid ester (II-1) is dissolved in 30 ml of ethanol, and water 2
0 ml and 1.0 g of sodium hydroxide were added, and the mixture was heated under reflux for 6 hours. After completion of the reaction, the reaction solution was made acidic, and the precipitated solid was collected by filtration and recrystallized from hexane-ethyl acetate to give the title compound (0.91 g). The results of measuring the physical properties of this compound were as shown below. The NMR spectrum was measured using TMS as an internal standard and indicated by the following symbols (same below). Melting point: 113-117 ° C IR (KBr method, ν, cm ^-1 ): 3188, 1694, 1624, 1586,
1466, 1238, 1058 NMR (CDCl ₃ , δ, ppm): 5.20 (2H, s), 6.4 ~ 6.8 (2H, m), 7.
1 to 7.6 (5H, m), 12.2 (1H, bs) s: Single line, d: Double line, m: Multiple line, b: Broad line

Production Example 2 Production of 2- (3-chlorobenzyloxy) -6-hydroxybenzoic acid (I-15) Anhydrous dimethylformamide 100
To ml, 480 mg of sodium hydride (60% oily sodium hydride washed with anhydrous hexane) was added with stirring under a nitrogen atmosphere, and then 3.36 g of 2,6-dihydroxybenzoic acid methyl ester was added, The mixture was stirred under ice cooling until bubbling stopped. In the obtained solution, 3-
A solution of 3.86 g of chlorobenzyl bromide dissolved in 30 ml of anhydrous dimethylformamide was added dropwise, and the mixture was stirred at a temperature of 40 ° C for 6 hours. The obtained reaction mixture was allowed to cool, then poured into ice water and extracted with ethyl acetate to obtain an organic layer. The organic layer was washed with water, dried over anhydrous sodium sulfate, and then the solvent was distilled off under reduced pressure. did. The obtained residue is purified by subjecting it to silica gel column chromatography,
3.5 g of salicylic acid ester (II-15) of the title compound
Obtained. 3.5 g of the obtained salicylic acid ester (II-15)
Was dissolved in 40 ml of ethanol, 20 ml of water and 3.5 g of sodium hydroxide were added, and the mixture was heated under reflux for 7 hours. After the reaction was completed, after acidifying the reaction solution, the precipitated solid was collected by filtration,
Recrystallized from hexane-ethyl acetate to give 3.0 g of the title compound.
I got The results of measuring the physical properties of this compound were as shown below. Melting point: 125-128 ° C IR (KBr method, ν, cm ^-1 ): 3190, 1692, 1620, 1584,
1450, 1234, 1060 NMR (CDCl ₃ + d ₆ -DMSO, δ, ppm): 5.07 (2H, s), 6.3 to 6.8
(2H, m), 7.0 ~ 7.6 (5H, m), 11.3 (1H, bs)

Table 2 in Table 2 shows the melting points and NMR data of the compounds produced by the operations according to the above Production Examples 1 and 2. The compound (II-1) and the compound (II-15) are also included.

[Table 2] ^A) : The symbols in the table indicate the following contents. s: Single line, d: Double line, m: Multiple line, b: Broad line

Formulation Example 1 Is pulverized and mixed and used as a dusting powder.

Formulation Example 2 Is pulverized and mixed to obtain a wettable powder, which is diluted with water before use.

Formulation Example 3 Are evenly mixed, water is further added and kneaded, and the mixture is processed into granules by an extrusion type granulator and dried to obtain granules.

Formulation Example 4 Are uniformly mixed and dissolved to obtain an emulsion.

Test Example 1 Cucumber downy mildew control effect test Cultivation was carried out using a unglazed pot (three sized pots) with a diameter of 9 cm.
1.2 Leaf stage seedling cucumber (variety: Sagami Hanshibushiri, 1 /
1 pot, 3 pots / used in the treatment area), the chemical solution prepared to a predetermined concentration was sprayed with a spray gun at an amount of 1000 l / ha. After air-drying the sprayed leaves, a suspension of zoosporangium of cucumber downy mildew collected from the diseased leaves was spray-inoculated and kept under high humidity conditions at 20 to 23 ° C overnight. After that, it is managed in a glass greenhouse, and 6 to 8 days after the inoculation, the degree of disease is 3 per test section according to the following survey criteria.
This investigation was carried out, and the control value (%) was calculated from the average disease degree per one by the following formula. Control value = (1 − degree of disease in treated area / degree of disease in untreated area) × 10
0 The results are shown in Table 3 in Table 3.

[0025]

[Table 3]

Test Example 2 Tomato epidemic control effect test Cultivation in a unglazed pot (three sized pots) with a diameter of 9 cm 3 to 4
Seedling tomatoes in the leaf stage (cultivar: Fukuju No. 2, 1 plant / 1 pot, 3 pots / used in the treatment group) were sprayed with a spray gun at a dose of 1000 l / ha equivalent to a chemical solution prepared to a predetermined concentration. After air-drying the sprayed leaves, a suspension of zoosporangia of Tomato anchovy was collected by spraying and inoculated, and kept overnight at 20-23 ° C in a high humidity condition. After that, it is managed in a glass greenhouse, and 6 to 8 days after the inoculation, 3 disease rates are examined per test section according to the following survey criteria, and the control value (%) is calculated from the average disease rate per one by the following formula.
Was calculated. Control value = (1 − degree of disease in treated area / degree of disease in untreated area) × 10
0 The results are shown in Table 4 in Table 4.

[0027]

[Table 4]

Test Example 3 Test for controlling green mold disease of kidney bean A kidney leaf (cultivar: Honkin) at the first true leaf cultivated in a unglazed pot (3 inch pot) having a diameter of 9 cm was prepared to a predetermined concentration. The chemical was sprayed with a spray gun at an amount of 1,000 l / ha.
After air-drying the sprayed leaves, circular slices (diameter 4 mm) of Botrytis cinerea-containing agar that had been pre-cultured for 3 days at 20 ° C in sugar-added potato decoction agar were placed directly on the center of each leaf. It was attached and kept under high humidity conditions at 20-23 ° C. On the 3rd day after the inoculation, 4 points of the disease rate were investigated per test section according to the following investigation criteria, and the control value was calculated from the average disease rate per line by the following formula. The morbidity was investigated according to the following investigation criteria by comparing with the lesion area of the untreated section, and the control value (%) was calculated by the following formula.

[0029] Control value = (1 − degree of disease in treated area / degree of disease in untreated area) × 10
The results are shown in Table 5 in Table 5.

[0030]

[Table 5]

Test Example 4 Rice Blast Control Effect Test 3 seedling or 4 leaf stage rice seedlings (cultivar: Sasanishi, 16 /
1 pot, 3 pots (used in the treatment area) were sprayed with a chemical solution adjusted to a predetermined concentration in an amount of 1000 l / ha. After air-drying the sprayed leaves, the rice blast fungus spore suspension formed on the rice bran-containing agar medium was spray-inoculated and kept at 25-28 ℃ high humidity for one day. After that, it is managed in a glass greenhouse and 6-8 after inoculation
After a day, the following survey criteria (Chinese agricultural trial rice blast survey criteria)
According to the survey, the disease rate was investigated for all seedlings per test plot,
The control value (%) was calculated from the average disease degree per one by the following formula. Control value = (1 − degree of disease in treated area / degree of disease in untreated area) × 10
0 The results are shown in Table 6 in Table 6.

[0032]

[Table 6]

[0033]

INDUSTRIAL APPLICABILITY The salicylic acid derivative of the formula (I · II) and its salt can be used as an active ingredient of an agricultural / horticultural fungicide.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C07C 255/54 C07C 255/54

Claims (3)

[Claims] 1. A fungicide for agricultural and horticultural use containing a salicylic acid derivative of the formula (I · II) of Chemical formula 1 or a salt thereof as an active ingredient. (In the formula, X is a lower alkyl group, a lower alkoxy group,
It represents a hydroxyl group, a halogen atom, a nitro group, a cyano group, a lower haloalkyl group, a phenoxy group or a dimethylamino group. Y represents a lower alkyl group or a halogen atom. n
Represents an integer from 0 to 5. When n is 2 or more, X
May be the same or different. m is 0 to 3
Represents the integer. When m is 2 or more, Y may be the same or different. R ¹ represents a hydrogen atom or a lower alkyl group) 2. A salicylate ester of formula (II) is synthesized by reacting a 2,6-dihydroxybenzoic acid derivative of formula (III) of formula 2 with a substituted benzyl halide of formula (IV),
Then, a method for producing a substituted salicylic acid of the formula (I), characterized in that the ester moiety is hydrolyzed. (In the formula, X
Represents a lower alkyl group, a lower alkoxy group, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a lower haloalkyl group, a phenoxy group or a dimethylamino group. Y represents a lower alkyl group or a halogen atom. n represents an integer of 0 to 5. When n is 2 or more, X may be the same or different. m represents an integer of 0 to 3. m
However, when 2 or more, Y may be the same or different. R represents a lower alkyl group. Z represents a halogen atom) 3. A salicylic acid derivative of the formula (I · II) represented by Chemical formula 3, or a salt thereof. [In the formula, X represents a lower alkyl group, a lower alkoxy group, a hydroxyl group, a halogen atom, a nitro group, a cyano group, a lower haloalkyl group, a phenoxy group or a dimethylamino group. Y represents a lower alkyl group or a halogen atom. n represents an integer of 0 to 5. When n is 2 or more, X may be the same or different. m
Represents an integer from 0 to 3. When m is 2 or more, Y
May be the same or different. R ¹ represents a hydrogen atom or a lower alkyl group. However, 2-benzyloxy-6-hydroxybenzoic acid, 2- (3,4-dimethylbenzyl) oxy-6-hydroxybenzoic acid, 2-benzyloxy-3,5-dibromo-4-methyl-6-hydroxybenzoic acid Acid methyl ester, 2-benzyloxy-6-hydroxybenzoic acid methyl ester and 2- (2,5-dimethoxybenzyl) oxy-6-hydroxybenzoic acid methyl ester are excluded]