JP2001233841A - Method for producing phenylhydrazines - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently carrying out an acid decomposition while suppressing dehalogenation in an intact state of water solvent because the dehalogenation is caused when the acid decomposition is conducted in the water to lower the yield and a method for removing the water from a phenylhydrazine derivative obtained in an aqueous solution is a process extremely bad at efficiency and a long time is required in the method for carrying out the acid decomposition of the phenylhydrazine derivative and thereby providing phenylhydrazines or mineral acid salts thereof. SOLUTION: This method for producing the phenylhydrazines represented by general formula (2) or mineral acid salts thereof comprises hydrolyzing a phenylhydrazine derivative represented by general formula (1) in the presence of water using a mineral acid in an amount so as to provide >=6 mol concentration based on 1 kg of water in the reactional system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to, for example, formula (4) The following general formula (2) useful as an intermediate of pyridazin-3-one compounds having excellent herbicidal activity represented by (Wherein X represents a hydrogen atom or a halogen atom;
Represents a halogen atom, W represents a hydrogen atom or ZR, Z represents an oxygen atom or a sulfur atom, R represents a hydrogen atom, a C1-C6 alkyl group, a C1-C6 haloalkyl group, a C3-C8 cycloalkyl group, benzyl Group, C
3-C6 alkenyl group, C3-C6 haloalkenyl group, C3-C6 alkynyl group, cyano C1-C6 alkyl group, C2-C8 (alkoxyalkyl) group, C
2-C8 (alkylthioalkyl) group, carboxy C1
-C6 alkyl group, (C1-C8 alkoxy) carbonyl C1-C6 alkyl group, {(C1-C4 alkoxy)
C1-C4 alkoxy @ carbonyl C1-C6 alkyl group, (C3-C8 cycloalkoxy) carbonyl C1-
C6 alkyl group or ｛(C1-C6 alkoxy)
Carbonyl C1-C6 alkyl dioxycarbonyl C1
-Represents a C6 alkyl group. )) Or a method for producing a mineral acid salt thereof.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 9-323977 discloses a general formula (3). (In the formula, X, Y and W represent the same meaning as described above.)
Describes a method for diazotizing an aniline derivative represented by the formula (1) and then reducing it with tin chloride to obtain a phenylhydrazine represented by the formula (2).

[0003]

However, in the above-mentioned method, since the reduction is carried out using tin chloride, when filtering insoluble tin compounds which are by-produced after the reaction, the filterability is poor. In addition, since it is necessary to treat the tin compound after the reaction, it is not always industrially a preferable method, and development of a method that does not use such a metal reducing agent has been desired. The present inventors obtained a phenylhydrazine derivative represented by the following general formula (1) by a method using no metal reducing agent, and acid-decomposed the obtained derivative to obtain a phenylhydrazine represented by the general formula (2). Or a mineral acid salt thereof, but when acid decomposition is carried out in water, dehalogenation (Y is eliminated in the general formula (1)) may occur, and the yield may decrease. all right. Further, in the case of a hydrophilic phenylhydrazine derivative, a method of removing water from a phenylhydrazine derivative obtained in an aqueous solution is a very inefficient process in terms of energy, and requires a long time. It has been desired to develop a method for efficiently performing acid decomposition while suppressing dehalogenation as it is.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, the following general formula (1)
When the phenylhydrazine derivative represented by the formula is hydrolyzed in water, the desired phenylhydrazine represented by the general formula (2) can be obtained in good yield by adjusting the amount of mineral acid per water in the reaction system. The present invention led to the heading.

That is, the present invention provides a compound represented by the general formula (1) (Wherein X represents a hydrogen atom or a halogen atom;
Represents a halogen atom, W represents a hydrogen atom or ZR, Z represents an oxygen atom or a sulfur atom, R represents a hydrogen atom, a C1-C6 alkyl group, a C1-C6 haloalkyl group, a C3-C8 cycloalkyl group, benzyl Group, C
3-C6 alkenyl group, C3-C6 haloalkenyl group, C3-C6 alkynyl group, cyano C1-C6 alkyl group, C2-C8 (alkoxyalkyl) group, C
2-C8 (alkylthioalkyl) group, carboxy C1
-C6 alkyl group, (C1-C8 alkoxy) carbonyl C1-C6 alkyl group, {(C1-C4 alkoxy)
C1-C4 alkoxy @ carbonyl C1-C6 alkyl group, (C3-C8 cycloalkoxy) carbonyl C1-
C6 alkyl group or ｛(C1-C6 alkoxy)
Carbonyl C1-C6 alkyl dioxycarbonyl C1
Represents a -C6 alkyl group, and Q is the same or different and represents a hydrogen atom, an ammonium or an alkali metal atom. The phenylhydrazine derivative represented by the formula (1) was used in the presence of water to reduce the amount of mineral acid to 6 / kg of water in the reaction system.
General formula (2) characterized in that hydrolysis is carried out at a concentration of at least molar. (In the formula, X, Y and W represent the same meaning as described above.)
And a method for producing a phenylhydrazine or a mineral salt thereof.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below. In the phenylhydrazine derivative represented by the general formula (1) used in the present invention, the halogen atom represented by X and Y includes a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. As the C1-C6 alkyl group for R,
Examples include a methyl group, an ethyl group, an isopropyl group, a propyl group, an isobutyl group, a butyl group, a t-butyl group, an amyl group, an isoamyl group, and a t-amyl group. Examples of the C1-C6 haloalkyl group include a 2,2,2-trifluoroethyl group. Examples of the C3-C8 cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and the like. C3-C6
Examples of the alkenyl group include an allyl group, a 1-methyl-2-propenyl group, a 3-butenyl group, a 2-butenyl group, a 3-methyl-2-butenyl group, a 2-methyl-3-butenyl group, and the like. As the C3-C6 haloalkenyl group,
2-chloro-2-propenyl group, 3,3-dichloro-2
-Propenyl group and the like. Examples of the C3-C6 alkynyl group include a propargyl group, a 1-methyl-2-propynyl group, a 2-butynyl group, and a 1,1-dimethyl-2-propynyl group. Examples of the cyano C1-C6 alkyl group include a cyanomethyl group. C2-C8
Examples of the (alkoxyalkyl) group include a methoxyethyl group, an ethoxymethyl group, and an ethoxyethyl group. As the C2-C8 (alkylthioalkyl) group,
And a methylthioethyl group. Carboxy C1-
Examples of the C6 alkyl group include a carboxymethyl group, a 1-carboxyethyl group, a 2-carboxyethyl group, and the like. (C1-C8 alkoxy) carbonyl C1-C6
Examples of the alkyl group include a methoxycarbonylmethyl group, an ethoxycarbonylmethyl group, a propoxycarbonylmethyl group, an isopropoxycarbonylmethyl group, a butoxycarbonylmethyl group, an isobutoxycarbonylmethyl group,
t-butoxycarbonylmethyl group, amyloxycarbonylmethyl group, isoamyloxycarbonylmethyl group,
t-amyloxycarbonylmethyl group, 1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group,
1-propoxycarbonylethyl group, 1-isopropoxycarbonylethyl group, 1-butoxycarbonylethyl group, 1-isobutoxycarbonylethyl group, 1-t-butoxycarbonylethyl group, 1-amyloxycarbonylethyl group, 1-isoamyl Examples thereof include an oxycarbonylethyl group and a 1-t-amyloxycarbonylethyl group. {(C1-C4 alkoxy) C1-C4 alkoxy} carbonyl C1-C6 alkyl group includes methoxyethoxycarbonylmethyl group, 1-methoxyethoxycarbonylethyl group and the like. Examples of the (C3-C8 cycloalkoxy) carbonyl C1-C6 alkyl group include a cyclobutyloxycarbonylmethyl group, a cyclopentyloxycarbonylmethyl group, a cyclohexyloxycarbonylmethyl group, a 1-cyclobutyloxycarbonylethyl group, and a 1-cyclopentyloxycarbonylethyl group. And a 1-cyclohexyloxycarbonylethyl group. {(C1-C6 alkoxy) carbonyl C1-C6 alkyl} oxycarbonyl C1-C6
Examples of the alkyl group include a (ethoxycarbonyl) methoxycarbonylmethyl group. Examples of the alkali metal atom for Q include sodium and potassium.

The phenylhydrazine derivative (1) of the present invention
Can be obtained, for example, by reacting a diazonium salt obtained by diazotizing an aniline derivative represented by the general formula (3) with a sulfite or a hydrogen sulfite.

As the diazotizing agent, nitrites are usually used, and specific examples thereof include sodium nitrite and potassium nitrite. Although nitrites may be added in the form of a solid, they are usually used in the form of an aqueous solution. The amount of the aniline derivative (3) is usually 1 to
The range is about 1.2 mol times.

In the diazotization reaction, a mineral acid is generally used. Examples of the mineral acid include hydrochloric acid, sulfuric acid, phosphoric acid, and the like.
Nitric acid and the like, preferably hydrochloric acid and sulfuric acid,
Usually used as an aqueous solution. The amount of the mineral acid to be used is usually about 1 to 10 mol times, preferably about 2 to 6 mol times, more preferably about 2.5 to 4 mol times with respect to the aniline derivative (3). It is.

The order of addition of the reaction reagents for the diazotization reaction is not particularly limited, but is usually performed by mixing the aniline derivative (3) with a mineral acid aqueous solution and then adding a nitrite aqueous solution. The reaction temperature is usually about -20C to 20C, preferably about -10C to 10C, more preferably -5C to 5C.
Range.

The sulfites used as the reducing agent include, for example, sulfurous acid, ammonium sulfite, sodium sulfite, potassium sulfite, and the like, and the bisulfites include ammonium bisulfite, sodium bisulfite, potassium bisulfite, and the like. These may be used in a solid state, but are usually used as an aqueous solution.

The amount of the sulfite or hydrogen sulfite used is usually at least 2 mol times, preferably about 2.5 to 4 mol times, relative to the diazonium salt obtained by diazotizing the aniline derivative (3). Range. P in the reaction system
H is usually adjusted to be in the range of 5.5 to 8, preferably in the range of 6 to 7.5. The pH can be adjusted with acids such as hydrochloric acid and sulfuric acid, or an aqueous alkali solution such as sodium hydroxide, potassium hydroxide and ammonia.

The above reaction is usually carried out using an aniline derivative (3)
The diazonium salt obtained by diazotizing the sulfonate is usually adjusted to pH 5.5 to pH of an aqueous solution of sulfites or bisulfites.
Add the solution adjusted to 8 and react. The reaction temperature is usually 0
It is in the range of about -80 ° C, preferably about 10-70 ° C.

The reaction time varies depending on the type of the reaction reagent, the amount of the reagent, and the reaction temperature, and is not particularly limited, but is usually in the range of about 30 minutes to about 24 hours.

After completion of the reaction, the obtained phenylhydrazine derivative (1) is filtered to obtain a hydrophobic derivative of the reaction mixture. When the derivative is water-soluble, the derivative can be obtained by concentration or extraction with an organic solvent followed by concentration. However, these can be further purified by recrystallization or the like. After the completion of the above reaction, the obtained phenylhydrazine derivative (1) can be used in the next step of a hydrolysis reaction with a mineral acid in the presence of an aqueous solvent without necessarily isolating it.

The raw material aniline derivative (3) can be obtained, for example, from European Patent Application Publication EP-61741-A; US Patent Specification USP 4,670,046, USP
4,770,695, USP 4,709,409, U
SP 4,640,707, USP 4,720,92
7, USP 5,169,431; JP-A-63-156
It can be produced according to a method known in, for example, 787 or the like or described therein.

Hereinafter, the phenylhydrazine derivative represented by the general formula (1) is exemplified in Table 1, but the present invention is not limited to these. General formula (1) Compound represented by

[Table 1]

In the present invention, the phenylhydrazine (2) or a mineral acid salt thereof can be obtained by hydrolyzing the phenylhydrazine derivative (1) with an acid. A mineral acid is used for the hydrolysis, and such a mineral acid preferably includes hydrochloric acid and sulfuric acid, and an aqueous solution of these mineral acids may be used. In the present invention, an organic solvent can be used in combination as long as the reaction is not inhibited.

The amount of the mineral acid to be used is usually 1 mol or more, preferably 4 to 50 mol, per mol of the phenylhydrazine derivative (1).

The amount of the mineral acid used is preferably 6 mol or more per 1 kg of water contained in the reaction system from the viewpoint of the reaction yield. Here, the water contained in the reaction system is the total of the water used in preparing the phenylhydrazine derivative (1) and the water contained in the mineral acid to be reacted with the phenylhydrazine derivative (1). The water used in preparing the phenylhydrazine derivative (1) is the water used in preparing the diazonium salt from the aniline derivative (3) and the water used in preparing the phenylhydrazine derivative (1) from the diazonium salt. Is the sum of
The water used in preparing the diazonium salt from the aniline derivative (3) is specifically exemplified by a commonly used production method, for example, the water in the aniline derivative (3), the water in the mineral acid, and the water in the nitrite. Of water and the water used for diluting them. Similarly to the water used for preparing the phenylhydrazine derivative (1) from the diazonium salt, the water used in the sulfite, the water used in the acid or alkali used for adjusting the pH, and the water used for diluting the same are used. And so on. Phenylhydrazine derivative (1)
Similarly, the water contained in the mineral acid to be reacted with is the total of the water contained in the mineral acid to be reacted with the phenylhydrazine derivative (1) and the water used for diluting them. However, when the phenylhydrazine derivative (1) is obtained by purification or when the aqueous solution of the phenylhydrazine derivative (1) is concentrated, it is necessary to correct the water content each time.

The production method of the present invention is generally carried out by using the phenylhydrazine derivative (1) or an aqueous solution (or suspension) thereof.
Is added to an acid or an aqueous acid solution to cause a reaction, and the aqueous solution (or suspension) of the phenylhydrazine derivative (1) is used.
, An acid or an aqueous acid solution may be added. Alternatively, the aqueous solution of the phenylhydrazine derivative (1) may be concentrated and reacted with an acid.

[0022] The reaction temperature is usually in the range of -5 ° C to 80 ° C, preferably 0 to 50 ° C. The reaction time varies depending on the type and amount of the reaction reagent and the reaction temperature, and is not necessarily limited. However, it can be generally selected from a range of about 30 minutes to about 24 hours.

After completion of the reaction, the resulting reaction mixture is filtered as it is, or neutralized with an aqueous alkali solution such as sodium hydroxide, and then filtered to obtain phenylhydrazines (2) or a salt thereof. Further, it can be purified by recrystallization or the like.

Thus, the phenylhydrazines (2) or the mineral salts thereof obtained in the present invention are exemplified in (Table 2), but the present invention is not limited to these. General formula (2) Compound represented by

[Table 2]

[0025]

According to the present invention, the phenylhydrazine derivative (1) is hydrolyzed with a mineral acid in the presence of an aqueous solvent without using a tin compound and without necessarily isolating the phenylhydrazine derivative (1). 2) or its mineral salt can be produced efficiently.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 4-chloro-2-fluoro-5-hydroxyaniline 1 was added to 1093.8 g of 10% hydrochloric acid.
62.0 g (content 99.6%, 0.999 mol) was added at 25 ° C. with stirring, and 205.9 g of a 35% aqueous sodium nitrite solution was added dropwise at −3 ° C. to 0 ° C. over 1 hour to diazotize. 1456.7 g of the corresponding diazonium salt aqueous solution
I got Then, to 1323.2 g of water, sodium sulfite 3 was added.
98.1 g was added, and pH 7.2 with 15.1 g of 95% sulfuric acid.
The diazonium salt was quickly added to the aqueous solution of sodium sulfite adjusted at 10 ° C at 10 ° C, and the temperature was raised to 65 ° C, and kept at that temperature for 2 hours to obtain 4-chloro-2-fluoro-5-hydroxyphenylhydrazine-N, N '. 3141.5 g of an aqueous solution of sodium disulfonate were obtained. LC-IS
From analysis, the yield of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine-N, N'-disulfonate sodium salt with respect to 4-chloro-2-fluoro-5-hydroxyaniline was 96.0%. The above-obtained aqueous solution of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine-N, N'-disulfonate sodium salt was cooled at 10 ° C to 2913.8 g of 35% hydrochloric acid (21.8%).
7.97 mol) over 2.5 hours.
The reaction was carried out for an hour to obtain 6048.7 g of a reaction mixture (90.0% of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine, 3.1% of dechloro product (by-product); LC area percentage). After filtering the reaction mixture, the filtration residue is dried and dried.
438.7 g of a mixture of -chloro-2-fluoro-5-hydroxyphenylhydrazine hydrochloride (light pink solid) was obtained (95.6% of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine, Creature) 0.3
%; LC area percentage). LC-IS analysis revealed that the yield of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine based on 4-chloro-2-fluoro-5-hydroxyaniline was 89.3%. The water in the reaction system includes water contained in 10% hydrochloric acid, water contained in a 35% aqueous sodium nitrite solution, water added to sodium sulfite, water contained in 95% sulfuric acid, and 35% hydrochloric acid. The total amount of water is 4336 g, and the amount of mineral acid used in the reaction system is 6.5 mol per 1 kg of water.

Example 2-1 107.7% hydrochloric acid 437.7
g, 4-chloro-2-fluoro-5-hydroxyaniline 65.0 g (content 99.6%, 0.401 mol), 3
83.1 g of a 5% aqueous sodium nitrite solution, water 539.6
g, 159.5 g of sodium sulfite, 95% sulfuric acid 12.
Using 7 g, 4-chloro-2 was obtained in the same manner as in Example 1.
-Fluoro-5-hydroxyphenylhydrazine-N,
N'-disulfonic acid sodium salt aqueous solution 1314.1
g was obtained. The aqueous solution was distilled at 56 ° C. and 107 mmHg for 4 hours to remove water and concentrated to 865.9 g. Example 2-2 35% hydrochloric acid cooled to 10 ° C.
5 g (2.146 mol) of 4-
Chloro-2-fluoro-5-hydroxyphenylhydrazine-N, N'-disulfonic acid sodium salt aqueous solution 2
66.4 g was added dropwise over 2.5 hours and reacted at the same temperature for 9 hours to obtain 486.5 g of a reaction mixture (4-chloro-).
2-fluoro-5-hydroxyphenylhydrazine 8
1.2%, 2.7% dechlorinated product (by-product); LC area percentage). After filtering the reaction mixture, the filtration residue was dried to obtain 61.9 g of a mixture of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine hydrochloride (light pink solid).
96.5% of chloro-2-fluoro-5-hydroxyphenylhydrazine, 0.1% of dechloro product (by-product); LC
Area percentage). LC-IS analysis showed that the yield of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine based on 4-chloro-2-fluoro-5-hydroxyaniline was 89.4%. The water content in the reaction system was 31
The amount of mineral acid used in the reaction system was 6.9 mol per 1 kg of water.

Example 3 4% in 135.8 g of 10% hydrochloric acid
-Chloro-2-fluoro-5-hydroxyaniline 2
0.1 g (content 99.6%, 0.124 mol) was added at 25 ° C with stirring, and 25.9 g of 35% aqueous sodium nitrite solution was added dropwise at -3 ° C to 0 ° C over 1 hour to diazotize. 181.7 g of the corresponding diazonium salt aqueous solution was obtained. Then, a 50% aqueous solution of ammonium bisulfite 73.
8 g was added with 41.0 g of a 30% aqueous sodium hydroxide solution.
A diazonium salt was quickly added to the solution adjusted to H7.2 at 10 ° C., and after the temperature was raised to 65 ° C., the temperature was kept at that temperature for 2 hours, and 4-chloro-2-fluoro-5-hydroxyphenylhydrazine-N, N 290.5 g of an aqueous solution of ammonium '-disulfonate was obtained. The aqueous solution of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine-N, N'-disulfonate ammonium salt obtained above
The mixture was added dropwise to 361.5 g (3.470 mol) of 35% hydrochloric acid cooled to 0 ° C over 2 hours, and reacted at the same temperature for 4 hours to obtain 648.4 g of a reaction mixture (4-chloro-2-fluoro-5). -Hydroxyphenylhydrazine 93.5%, dechloro form (by-product) 0.6%; LC area percentage). After filtering the reaction mixture, the filtration residue was dried to obtain 44.4 g of a mixture of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine hydrochloride (light pink solid) (4-chloro-2-).
Fluoro-5-hydroxyphenylhydrazine 96.5
%, No dechloro product (by-product) detected; LC area percentage).
According to LC-IS analysis, the yield of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine based on 4-chloro-2-fluoro-5-hydroxyaniline was 88.0%.
Met. The amount of water in the reaction system was 440 g, and the amount of mineral acid used in the reaction system was 7.9 mol per 1 kg of water.

Example 4 896.4 g of 10% hydrochloric acid, 4
-Chloro-2-fluoro-5-hydroxyaniline 13
2.9 g (content 99.6%, 0.819 mol), 35%
169.6 g of aqueous sodium nitrite solution, 1084.5 water
g, 326.2 g of sodium sulfite, 96% sulfuric acid 14.
Using 8 g, 4-chloro-2 was obtained in the same manner as in Example 1.
-Fluoro-5-hydroxyphenylhydrazine-N,
N'-disulfonic acid sodium salt aqueous solution 2610.6
g was obtained. 4-chloro-2-fluoro- obtained above
200.0 g of an aqueous solution of sodium 5-hydroxyphenylhydrazine-N, N′-disulfonate was cooled to 10 ° C., and 178.5 g (1.747 mol) of 96% sulfuric acid was charged at the same temperature over 30 minutes, and 15 ° C. For 2 hours to obtain 377.9 g of a reaction mixture (4-chloro-2-fluoro-5-hydroxyphenylhydrazine 90.4%, dechloro form (by-product) 1.2%; LC area percentage). After filtering the reaction mixture, the filtration residue was washed with 115.7 g of a saturated saline solution and dried, and a mixture of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine sulfate (light gray solid) was obtained.
21.2 g were obtained (4-chloro-2-fluoro-5-hydroxyphenylhydrazine 96.2%, dechloro form (by-product) 0.3%; LC area percentage). LC-IS analysis revealed that the yield of 4-chloro-2-fluoro-5-hydroxyphenylhydrazine based on 4-chloro-2-fluoro-5-hydroxyaniline was 85.5%.
The water content in the reaction system was 161 g, and the amount of mineral acid used in the reaction system was 10.9 mol per 1 kg of water.

The results of the examples are shown in Table 3.

[Table 3] Note) Yield based on anilines.

Claims (3)

[Claims] 1. The general formula (1) (Wherein X represents a hydrogen atom or a halogen atom;
Represents a halogen atom, W represents a hydrogen atom or ZR, Z represents an oxygen atom or a sulfur atom, R represents a hydrogen atom, a C1-C6 alkyl group, a C1-C6 haloalkyl group, a C3-C8 cycloalkyl group, benzyl Group, C
3-C6 alkenyl group, C3-C6 haloalkenyl group, C3-C6 alkynyl group, cyano C1-C6 alkyl group, C2-C8 (alkoxyalkyl) group, C
2-C8 (alkylthioalkyl) group, carboxy C1
-C6 alkyl group, (C1-C8 alkoxy) carbonyl C1-C6 alkyl group, {(C1-C4 alkoxy)
C1-C4 alkoxy @ carbonyl C1-C6 alkyl group, (C3-C8 cycloalkoxy) carbonyl C1-
C6 alkyl group or ｛(C1-C6 alkoxy)
Carbonyl C1-C6 alkyl dioxycarbonyl C1
Represents a -C6 alkyl group, and Q is the same or different and represents a hydrogen atom, an ammonium or an alkali metal atom. The phenylhydrazine derivative represented by the formula (1) was used in the presence of water to reduce the amount of mineral acid to 6 / kg of water in the reaction system.
General formula (2) characterized in that hydrolysis is carried out at a concentration of at least molar. (In the formula, X, Y and W represent the same meaning as described above.)
And a method for producing a phenylhydrazine or a mineral acid salt thereof. 2. The general formula (3) (In the formula, X, Y and W represent the same meaning as described above.)
The diazonium salt obtained by diazotizing the aniline derivative represented by the formula is reacted with sulfites or bisulfites, and then the concentration of the mineral acid in the presence of water is at least 6 mol / kg of water in the reaction system. The method according to claim 1, wherein the hydrolysis is carried out. 3. The method according to claim 1, wherein after the hydrolysis, the phenylhydrazine represented by the general formula (2) or a mineral acid salt thereof is filtered.