JPH02202878A - Production of 2-phenylbenzotriazoles - Google Patents

Abstract

PURPOSE:To produce the subject compound useful as an ultraviolet absorber in high yield at a low cost by reducing an o-nitroazobenzene derivative with an alcohol in the presence of water and a base while using a specific cyclic ketone as a catalyst and a specific aromatic compound as a cocatalyst. CONSTITUTION:The objective compound of formula II is produced by reducing an o-nitroazobenzene derivative of formula I (R1 is H, Cl, 1-4C lower alkyl, etc.; R2 is H, Cl, 1-4C lower alkyl, etc.; R3 is H, Cl, 1-12C alkyl, etc.; R4 is H, Cl, hydroxy, etc.) with at least one kind of alcohol selected from primary alcohol and secondary alcohol in the presence of water and a base using a catalyst consisting of a cyclic ketone having ketone group adjacent to an aromatic group (especially preferably 9-fluorenone, etc.) and a cocatalyst consisting of an aromatic compound having >=2 hydroxyl group (especially preferably catechol, hydroquinone, etc.).

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for producing 2-phenylbenzotriazoles represented by the following general formula (2), which are useful as ultraviolet absorbers.

[Prior art]

General formula ■ (However, R1 represents hydrogen or a chlorine atom, a lower alkyl group having 1 to 4 carbon atoms, a lower alkoxyl group having 1 to 4 carbon atoms, a carboxyl group, or a sulfonic acid group, and R2 represents a hydrogen or chlorine atom, a carbon number 1-4 lower alkyl group or 1-4 carbon atoms
4 represents a lower alkoxyl group, and R3 is a hydrogen or chlorine atom, an alkyl group having 1 to 12 carbon atoms, a lower alkoxyl group having 1 to 4 carbon atoms, a cycloalkyl group, a phenyl group, an alkyl group having 1 to 8 carbon atoms. Represents a substituted phenyl group, phenoxy group, or phenylalkyl group whose alkyl moiety has 1 to 4 carbon atoms, R4 represents a hydrogen or chlorine atom, a hydroxyl group, or an alkoxyl group having 1 to 4 carbon atoms,
R9 represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a phenylalkyl group having 1 to 4 carbon atoms in the alkyl portion. ) 2-phenylbenzotriazoles are known as ultraviolet absorbers that are added to plastics, paints, oils, etc.

It is known to reduce 0-nitroazobenzene derivatives of the general formula (1) to 2-phenylbenzotriazoles of the general formula (1) in a basic alcohol medium.

However, this reduction is characterized by the use of aromatic dihydroxy compounds or quinone compounds as catalysts, as well as the presence of further reducing agents, such as zinc, ammonium sulfide, alkali metal sulfides, hydrosulfides or hydrazine. ).

When metals, especially zinc, are used in this way, a large amount of zinc sludge is generated, which causes drainage problems, and sulfide-based reducing agents generate toxic hydrogen sulfide, and hydrosulfides generate sulfur dioxide gas, which causes air pollution. It also leads to problems. Hydrazine is indeed a strong reducing agent, but due to its high toxicity, great care must be taken in its handling.

JP-A-59-170172 filed by the present applicant uses quinones, and JP-A-63-72682 uses aromatic ketones as a catalyst in a basic medium to produce an 0-nitroazobenzene derivative of general formula I. A method for reducing with alcohols is described.

Although this method is an excellent method for solving air pollution and wastewater pollution, quinones irritate the skin and mucous membranes and may cause rashes, making them difficult to handle, and the yield is relatively good. The product has a strong yellow tinge, making it unsuitable as an additive for colorless plastics.

Although the method disclosed in JP-A-63-72682, which uses aromatic ketones, does not have any disadvantages in handling, it uses an expensive catalyst, is inferior to the former in terms of yield, and generates rapid heat generation during the reaction. However, it has drawbacks that make it unsuitable for large-scale industrial production.

This tendency is particularly strong when R3 in the general formula (2) is an alkyl group and R1, R2, R4°R3 are hydrogen atoms.

〔the purpose〕

An object of the present invention is to provide a method for producing 2-phenylbenzotriazoles that can solve all the problems inherent in the above-mentioned conventional techniques.

〔composition〕

The present inventors have investigated the above-mentioned problems in the conventional method for producing 2-phenylbenzotriazoles, and in particular,
As a result of intensive research in order to exceed the yield of No. 72682 and at the same time solve the problem of heat generation, 1) A cyclic ketone adjacent to an aromatic ring consisting of a catalytic amount of 0-nitroazobenzenes of general formula I, two or more hydroxy 2) reduction with an aromatic compound having a group and an alcohol selected from the group consisting of primary alcohols and secondary alcohols having 3 or more carbon atoms in the presence of water and a base, or 2) general A 2-phenylbenzotriazole-N-oxide represented by the formula (1) is treated in the presence of a catalytic amount of a cyclic ketone adjacent to an aromatic ring, an aromatic compound having two or more hydroxy groups, water, and a base. By reducing with alcohols selected from the group consisting of primary alcohols and secondary alcohols having 1 or more carbon atoms, the target product of general formula It has been found that the yield is much higher than that of the method of JP-A No. 63-72682, and at the same time it can be obtained without rapid heat generation.

That is, in the present invention, the presence of an aromatic compound having two or more hydroxyl groups in addition to the cyclic ketone adjacent to the aromatic ring and an appropriate amount of water are key to improving the yield.

In general, alcohols are hydrophilic and have the property of arbitrarily mixing with water when water is added, or dissolving water within a certain range. When a base is added to an alcohol of 03 or higher in which water is dissolved, it separates into two layers: an aqueous layer containing most of the base and an alcohol layer containing a small amount of the base. The present invention takes advantage of this property. There are two or more hydroxy compounds in the aqueous layer, and a large amount of cyclic ketones adjacent to aromatic rings in the alcohol layer, and the reduction reaction of the general formula It progresses slowly and without any side reactions.

Aqueous methanol and aqueous ethanol of C3 or higher do not separate into two layers even when a base is added, so even if the method of the present invention is carried out, the yield is low or the reaction does not proceed at all.

The method 1) of the present invention includes the reaction temperature, reaction time and first
The process is carried out through the following one or two steps depending on the consumption amount of primary alcohols or secondary alcohols.

(i) In the case of 1 step (step a below) In this case, the reaction temperature is 60 to 110°C, the reaction time is 3 hours to 12 hours, and the amount of primary alcohol used at that time is the same as that of the compound of formula (1). 0.9 to 1.3 per mole molecule
molar molecule, and the amount of secondary alcohol used is 1.8~
It is 2.6 mole molecules.

Reaction formula for secondary alcoholsFor alicyclic alcohols such as cyclohexanol, (
).

Reaction formula in the case of primary alcohols (R' and R' are the same or different alkyl groups) (in the formula, R represents an alkyl group) (ii) In the case of two steps (steps A and C below) In this case In the process, the reaction temperature is initially about 60-100℃, and the time is about 2-100℃.
In step C, the reaction temperature is 70 to 110°C and the time is suitable for 1 to 6 hours.

Although this method involves two steps, it may be more advantageous in terms of quality and yield than a one-step method.

The amount of alcohol used is 0.4 to 0.7 mol molecule of primary alcohol per mol molecule of the compound of formula I in the step,
The secondary alcohol is 0.8 to 1.4 mol molecule, and in step C, the compound of formula (1) is 1 mol, the primary alcohol is 0.4 to 0.7 mol molecule, and the secondary alcohol is 0. 8
~1.4 mole molecules.

(Left below) Step b R = Alkyl group Step C Step C R = Alkyl group Reaction formula for secondary alcohols In the case of alicyclic alcohols such as cyclohexanol (
).

In the method of the present invention, in order to facilitate the reaction in both (i) and (ii), alcohols used for reduction are usually used as a solvent, and in some cases, toluene, acetone,
It can also be carried out in an inert solvent such as dimethyl sulfoxide or acetonitrile. In addition, phase transfer aid,
A surfactant can also be used in combination.

General formula ■ used as a raw material in method (i) of the present invention
Specific examples of the compound include the following.

2-nitro-4-chloro-21-hydroxy-3',5
'-di-t-amyl azobenzene, 2-nitro-4-chloro-2'-hydroxy-3'-t
-Butyl-5'-methylazobenzene, 2-nitro-2'-hydroxynzene, 5'-t-amyl azobe-2-nitro-2'-hydroxyzene, 5'-methylazoben 2-nitro-4-chloro-2'- hydroxy-5'-t
-Amyl azobenzene, 2-nitro-2'-hydroxy-5'-t-octylazobenzene, 2-nitro-2'-hydroxy-3',5'-di(α,
α-dimethylbenzyl)azobenzene, 2-nitro-2'-hydroxy-5'-t-butylazobenzene, 2-nitro-4-chloro-2'-hydroxy-3', 5
'-di(α,α-dimethylbenzyl)azobenzene,
2-nitro-4-chloro-2'-hydroxy-3',5
'-di-t-butylazobenzene, 2-nitro-2'-hydroxy-3'-α-methylbenzyl-5'-methylazobenzene, 2-nitro-2'-hydroxy-3', 5'-di-t −
Amylazobenzene, 2-nitro-4-chloro-2'-hydroxy-3'-α
-Methylbenzyl-5'-methylazobenzene, 2-nitro-2'-hydroxy-3', 5'-di-t-butylazobenzene, 2-nitro-2'-hydroxy-5'-n-dodecyl azobenzene, 2 -nitro-2'-hydroxy-3'-t-butyl-5
'-Methylazobenzene, 2-nitro-4-chloro-2'-hydroxy-5'-n
-dodecyl azobenzene, 2-nitro-2',4'-dihydroxyazobenzene,
2-nitro-4-chloro-2', 4'-dihydroxyazobenzene, 2-nitro-2'-hydroxy-3', 5'-di-t-
Octylazobenzene, 2-nitro-21-hydroxy-4'-methoxyazobenzene, 2-nitro-4-chloro-2'-hydroxy-3', 5
'-di-t-octylazobenzene, 2-nitro-4 chlor2'-hydroxy-5'-t-octylazobenzene, 2-(2-hydroxy-3-t-butyl-5-methylphe2-nitro-4-methyl -2'-hydroxy-5'-
Methyl azobenzene, 2-nitro-4-methyl-2'-hydroxy-3'-t
-butyl-5-methylazobenzene, cyto, 5ee-butyl-5' -t-butylazobenzene, 2
-nitro-4-t-butyl-2'-hydroxy-3'-
5ec-butyl-5'-t-butylazobenzene, 2-
Nitro-4,6-dichloro-2'-hydroxy-5'-
t-Butylazobenzene, nyl)benzotriazole-N-oxide, 2 of the present invention
The compound of the general formula (1) used in the method (2) can be obtained, for example, by reducing the compound of the above-mentioned general formula I to an N-oxide, and specific examples thereof include the following.

nzotriazole-N-oxide, oxide, and Do.

In addition, these N-oxides of general formula (2) are 0 of general formula (I)
Although it is preferable to use the -nitroazobenzene derivative as a raw material and produce it by the method described in step (i) above, it is also possible to produce it by other known methods.

Alcohols that are reducing agents of the present invention include n-propanol, n-butanol, isobutanol, n-amyl alcohol, isoamyl alcohol, n-hexanol, cyclohexanol, 2-ethylbutanol, n-
Heptyl alcohol, n-octatool, 2-ethylhexanol, 3,5.5= trimethylhexanol,
Examples include n-decanol, dodecanol, tetradecanol, isopropyl alcohol, sec-butanol, 3-pentanol, methyl amyl alcohol, 2-to-20-butanol, 3-heptatool, 2-octatool, nonanol, undecanol, etc. .

Among them, n-propanol, n-butanol, n-amyl alcohol, isopropyl alcohol, isobutanol, sec-butanol, and 27-myl alcohol are preferred.

It is preferable to use more than a chemical equivalent of the primary or secondary alcohol, and since the solvent for the reaction is generally used, the starting material is 1 mol molecule of the O-nitroazobenzene of formula (1) or the general formula (I 3 to 50 mol molecules, preferably 6 to 2 mol molecules per 1 mol molecule of the N-oxide of [[)
Use 0 mole molecules.

Furthermore, even if two or more types of alcohols are mixed, there is no adverse effect on the reaction, and favorable results may be obtained in some cases.

The water used during the reaction is per 1 mole molecule of formula I and formula
2 to 40 mol molecules, preferably 5 to 30 mol molecules. Therefore, when an alcohol having dissolved water within this range is used as a reducing agent, it can be used without dehydration, which is very advantageous industrially.

Specific examples of the cyclic ketones adjacent to the aromatic ring that are the catalysts of the present invention include anthrones such as benzanthrone, fluorenones such as 9-fluorenone, and xanthenones such as 9-xanthenon. Among them, 9-fluorenone and benzanthrone are preferred. Two or more of these may be mixed.

In any case, the amount used is given by formula (1). - It is suitably 0.05 to 0.5 mol molecules, preferably 0.1 to 0.3 mol molecules per 1 mol molecule of the nitroazobenzene.

Also, when N-oxides of formula (III) are used as starting materials, 0.0
5 to 0.5 mol molecules, preferably 0.1 to 0.3 mol molecules.

The cyclic ketone adjacent to the aromatic ring that is the catalyst of the present invention is insoluble in water but soluble in organic solvents such as toluene, xylene, and alcohol, and has a boiling point. It can be recovered by extractive distillation and reused for the next reaction. Compared to the method of JP-A No. 63-72682, in the method of the present invention, the catalytic ability of ketones lasts for a long time, so that the reactions in Steps B and C proceed only by adding a predetermined amount at the beginning of the reaction. In the method of JP-A-63-72682, the capacity of the ketone catalyst decreases, and even in Step C, the reduction reaction may not proceed unless a ketone catalyst is added.

Aromatic compounds with two or more hydroxy groups that serve as cocatalysts (promoters) include those at the 1st and 2nd positions or the 1st and 4th positions of the aromatic ring.
Compounds having an OH group at this position are preferred. This is expected to be due to the formation of quinone bonds at the 1, 2 and 1°4 positions upon oxidation.

When the aromatic ring is anthracene, those having OH groups at the 1.2-position, 1,4-position and 9- and 10-position are preferred for the same reason. Particularly preferred are catechols, hydroquinones, naphthohydroquinones, and anthrahydroquinones.

Note that the aromatic ring can be substituted with an alkyl group, halogen, or alkoxy group.

Representative examples of these promoters include catechol, hydroquinone, chlorohydroquinone, pyrogallol, 4-methylcatechol, 1.2.4-trihydroxybenzene, 2,5-dioxy-P-xylene, 2,3
, 5,6-titramethylhydroquinone, 2,5.2'
, 5'-tetraoxybiphenyl (dihydroquinone),
1,4-dioxynaphthalene (α-naphthohydroquinone), 1,2-dioxynaphthalene (β-naphthohydroquinone), 9,10-dioxyanthracene (9,10-
anthrahydroquinone), 1,2-dioxyanthracene, 1,2,5.8-tetraoxyanthracene, etc. Among these, catechol, hydroquinone, 3
, 4-dihydroxytoluene is particularly preferred. The amount used is suitably 0.05 to 0.5 mol, preferably 0.1 to 0.5 mol, per 1 mol of the compound corresponding to formula (I) or formula (m). Although this compound after use is deteriorated and cannot be recovered, the improved yield of the expensive formula (2) is sufficiently satisfactory.

As the base, sodium hydroxide or potassium hydroxide is preferred. The amount used is suitably 1 to 12 mol molecules, preferably 2 to 8 mol molecules, per 1 mol molecule of the 0-nitroazobenzene of formula (1) or the N-oxide of formula (DI).

〔Example〕

Example 1 A mixture of 128.2 g (1.73 mole molecules) of sec-butanol, 32.1 g (1.78 mole molecules) of water, and 16.5 g (0.4 mole molecules) of 97% caustic soda was -2'Hydroxy-5'-t-octylazobenzene 35.5g (0.1 mol molecule) was added, and the temperature was raised to 65°C with stirring, then to 50°C, and 9-fluorenone 3
．． 6 g (0.02 mol molecules) and 2.2 hydroquinone
g (0.02 mol molecules) and then the boiling point (92°C)
When the temperature is raised to 100% and stirred for 3 hours, most of the azobenzene disappears and the reaction in the step is completed.

To carry out the reaction in the next step C, cool to 70°C, add 8.2g (0.2 mol molecule) of 97% caustic soda, and stir for 4 hours at the boiling point (93°C), the N-oxide will disappear. The reaction of step C is completed. Add 140mΩ of water, 62
．． Approximately 41 g of 5% sulfuric acid was used to make P old 1.0 to 11.5, and 10
℃ to below, separate the precipitated crystals, wash with a small amount of methanol, thoroughly wash with water, and dry to obtain the desired product 2.
-(2-hydroxy-5-t-octylphenyl)benzotriazole is obtained.

Yield 28.8 g Yield 89.1% Melting point lo
3-105℃ Example 2 The amount of hydroquinone used in Example 1 was (a) 1, Ig(
0.01 mol molecule), (b) 3.3 g (0.03 mol molecule), and (c) catechol 2.2 g (0.02 mol molecule) instead of hydroquinone, (d) 3. 3g
(0.03 mol molecule), (e)pyrogallol 2.5 g (
(0,02 mol molecule), (f) 2.5 g (0,02 mol molecule) of 3,4-dihydroxytoluene, (t) 1.6 g (0, oi mol molecule) of 1,4-dihydroxynaphthalene were used, The same method as in Example 1 was repeated to obtain 2-(2-hydroxy-5-t-octylphenyl)benzotriazole in the following yields.

(A) 28.0g Yield 86.7% Melting point 1
03-105°C (b) 29.0g Yield 89.
8% Melting point 103-105°C (c) 28.0g
Yield 86.7% Melting point 103-105℃ (d)
28.8g Yield 89.1% Melting point 103~
105°C (E) 27.9g Yield 86.3%
Melting point 103-105°C (f) 27.6g Yield 85.4% Melting point 103-105°C (t) 2
7.9g Yield 86.3% Melting point 103-105
°C Comparative Example 1 (The same procedure was followed as in Example 1 except that no hydroquinone was used) 128.2 g (1,73 mol molecules) of sec-butanol, 32.1 g (1,78 mol molecules) of water, and 97% caustic soda 35.5 g (0.1 mol molecule) of 2-nitro-2'-hydroxy-5'-t-octylazobenzene was added to a mixture of 16.5 g (0.4 mol molecule), and the temperature was raised to 65°C while stirring. After that, 3.6 g of 9-fluorenone (0,0
After adding 2 moles of molecules), the temperature was raised to the boiling point (92°C),
After stirring for 6 hours, most of the azobenzene disappears and the reaction in the step is completed.

In order to carry out the reaction in the next step C, the temperature was cooled to 70°C, 8.2g (0.2 mol molecules) of 97% caustic soda was added, and the boiling point (93
C), and the reaction is continued at the same temperature for 4 hours (at the beginning of this reaction there is rapid heat generation, and if it boils violently, cooling is required), the N-oxide disappears and the reaction in Step C is completed. Add 160m of water and add about 41g of 62.5% sulfuric acid to P.
After neutralizing to H11.0 to 11.5, cooling to below 10°C, separating the precipitated crystals and washing with a small amount of methanol,
When thoroughly washed with water and dried, the yield was 26.5 g.
-hydroxy-5-t-octylphenyl)benzotriazole is obtained.

Yield: 82.0% Melting point: 103-105°C The reaction in Step C takes a long time, and there is a violent exothermic reaction in Step C, making control difficult. .5 to 7.8% lower.

Comparative Example 2 2-(2-hydroxy-
The yield of 5-t-octylphenyl)benzotriazole was 20.0 g to z6. tg (yield 61.9-80.8%
), the yield was unstable.

Example 3 74.2 g (1.0 mole molecule) of sec-butanol, 22 g of water
．． 3 g (1,24 mol molecules) and 10.3 g (0,25 mol molecules) of 97% caustic soda, 35.5 g (0,1 2.2 g (0.02 mol molecule) of hydroquinone and 3.6 g (0.02 mol molecule) of 9-fluorenone were added, and the boiling point (92 mol molecule) was added. ℃) and stirred for 3 hours, most of the azobenzene disappears and the reaction in the step ends.

To carry out the reaction in the next step C, the temperature was cooled to 70°C, 8.2 g (0.20 mol molecule) of 97% caustic soda was added, and the mixture was stirred at the boiling point (94°C) for 5 hours. reaction ends. After adding 140 mQ of water, excess 2-butanol and methyl ethyl ketone produced as a by-product in the reduction reaction are recovered by distillation. Add 80mR of toluene to the residual liquid after recovery, and adjust the pH to 11 with about 30g of 62.5% sulfuric acid.
0 to 11.5.

The contents are heated to 70°C, and the toluene layer containing the target substance is collected and washed 2 to 3 times with small amounts of warm water (50 to 60°C).

This toluene layer is taken into a distillation flask and distilled to recover toluene. After recovering toluene, under a vacuum of 3 to 5 mnHg,
3.2 g of fraction at 140-160°C is collected. This is the 9-fluorenone used and can be reused as the next catalyst.

130+nQ in the residual liquid (oil) after 9-olefin recovery
of ethanol and stirred for a while at 70-75°C, crystals will precipitate, so they are separated by filtration and dried.
A yield of 9.0 g of 2-(2-hydroxy-5-t-octylphenyl)benzotriazole is obtained.

Yield 89.8% Melting point 103-105°C Example 4 n-butanol 74.2g (1.0 mol molecule), water 10
．． 6 g (0,82 mol molecules) and 97% caustic soda 1
2.4 g (0.3 mol molecules) of 2-nitro-
After adding 38.3 g (0.1 mol molecule) of 2'-hydroxy-3',5'-di-t-amyl azobenzene and raising the temperature to 65°C with stirring, 3.6 g (0,0 mol molecule) of 9-fluorenone was added.
2 mol molecules) and 2.2 g (0.02 mol molecules) of catechol were heated to 90°C, and then heated at 90-96°C for 3
After stirring for a period of time, most of the azobenzene disappears and the reaction in step S is completed.

To carry out the reaction in the next step C, cool to 70°C, add 12.4g (0.3 mol molecule) of 97% caustic soda, and then stir and react at 93-96°C for 3 hours to eliminate N-oxide. The reaction of step C is completed. Add 140 m of water, adjust the pH to 11.0-11.5 with about 30 g of 62.5% sulfuric acid, and let it stand at 60-70°C. A butanol layer containing amyl phenyl)benzotriazole is formed, and an aqueous layer is formed below.

After removing the lower aqueous layer, the upper butanol layer was heated to 80°C.
After washing with 50 mm of warm water, transfer to a distillation vessel, recover the butanol under normal pressure or light vacuum, and then reduce the vacuum level to 3 to 5 mmH.
g and 3.3 g of fraction at 140-160°C are collected. This is the catalyst 9-fluorenone used and can be reused as the next catalyst.

Add 130 mQ of ethanol to the residue after recovering the catalyst,
If you stir for a while at 70-75℃, crystals will precipitate, so if you separate them by filtration and dry them, 2-(
A yield of 20.0 g of 2-hydroxy-3,5-di-t-amylphenyl)benzotriazole was obtained.

Yield: 89.7% Melting point: 78-80°C Comparative Example 3 The same procedure as in Example 4 was carried out without using catechol, with caution being taken to prevent rapid heat generation.

Yield 28.9 g Yield 82.3% Melting point 78
~80°C Example 5 120 g of isopropyl alcohol (2.0 mol molecules),
2-nitro-4-chloro-2'-hydroxy-3',5'-di-t
- Add 39.0 g (0.1 mol molecule) of butylazobenzene and raise the temperature to 65°C with stirring, then 2.2 g of catechol.
(0,02 mol molecules) and 3.6 g of 9-fluorenone
(0.02 mol molecule) was added and reacted with stirring for 6 hours at a boiling point of 79°C, azobenzene disappeared and 2-(2-hydroxy-3,5-di-t-butylphenyl)-5-chlorobenzotriazole N- Oxide is produced and the reaction in step S is completed.

Next, in order to carry out the reaction in step C, it was cooled to 60°C and 97%
After adding 12.4 g (0.3 mol molecules) of caustic soda and reacting with stirring at the boiling point (80° C.) for 6 hours, the N-oxide disappears and the reaction of Step C is completed. After adding 140 m of water, the pH is adjusted to 11.0 to 11.5 with about 41 g of 62.5% sulfuric acid. Cool to 10° C. or below, separate the precipitated crystals by filtration, wash with a small amount of isopropyl alcohol, thoroughly wash with water, and dry. A yield of 29.7 g of 2-(2-hydroxy-3,5-di-t-butylphenyl)-5-chlorobenzotriazole is obtained.

Yield: 83.0% Melting point: 153-155°C Comparative Example 4 The same procedure as Example 5 was carried out except that catechol was not used.

Yield 27.2g Yield 76.0% Melting point 153
~155°C Example 6 Isobutanol 74.2g (1.0 mol molecule), water 18
．． 0 g (1,0 mole molecule) and 97% caustic soda 24
．． 7 g (0.6 mol molecules) of 2-nitro-4chloro-2'-hydroxy-3'-t-butyl-5
34.8 g (0.1 mol molecule) of '-methylazobenzene was heated to 65°C with stirring, and 2.2 g (2.2 g) of hydroquinone (
0.02 mol molecules) and 3.6 g of 9-fluorenone (
After adding 0.02 mol molecules), the temperature was gradually raised to 94-9
When the mixture is heated and stirred at 8° C. for 6 hours, step (c) proceeds and the reduction reaction is completed. Add 140mR of water, 62.5
Adjust the pH to 11.5 to 11.0 with about 34 g of % sulfuric acid and heat at 10°C.
After cooling, the precipitated crystals were separated, washed with a small amount of methanol, thoroughly washed with water, and dried, yielding 26.8 g of 2-(2-hydroxy-3-t-butyl-5-methylphenyl)- 5-chlorobenzotriazole was obtained.

Yield: 84.9% Melting point: 138-140°C Comparative Example 5 The same procedure as Example 6 was carried out except that hydroquinone was not used.

Yield 24.9 g Yield 78.9% Melting point 13
8-140℃ Example 7 2-butanol 74.2g (1.0 mol molecule), water 18
．． 0 g (1,0 mole molecule) and 97% caustic soda 22
．． 7 g (0,55 mol molecules) of 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-
33.2 g of chlorobenzotriazole-N-oxide (
After adding 0.1 mol molecule) and raising the temperature to 65°C with stirring, 2.2 g (0.02 mol molecule) of catechol and 9-
After adding 3.6 g (0.02 mol molecule) of fluorenone and reacting at the boiling point for 5 hours, the N-oxide disappears and the reduction reaction is completed.

Add 140 m of water, adjust the pH to 11.0 to 11.5 with about 37 g of 62.5% sulfuric acid, cool to below 10°C, separate the precipitated crystals in a furnace, wash with a small amount of methanol, thoroughly wash with water, and dry. 2-(2-hydroxy-3-t-butyl-5-methylphenyl)-5- with a yield of 29.7 g.
Chlorbenzotriazole was obtained.

Yield: 94.1% Melting point: 139-140°C Comparative Example 6 The same procedure as Example 7 was carried out except that catechol was not used.

Yield 29.4 g Yield 93.2% Melting point 13
9-140°C Example 8 2-butanol 74.2g (1.0 mol molecule), water 22
．． 3 g (1,24 mol molecules) and 97% caustic soda 1
35.5 g (0.1 mol molecule) of 2-nitro 2'-hydroxy-3',5'-di-t-butylazobenzene was added to a mixture of 0.3 g (0.25 mol molecule) and while stirring. After raising the temperature to 65°C, 2.2 g of hydroquinone (0.02
mol molecule) and benzanthrone 2.3 g (0,01
After adding mol molecule), the temperature is raised to the boiling point (92°C) and stirred for 4 hours, whereby most of the azobenzene disappears and the reaction in the step is completed.

To carry out the reaction in the next step C, cool to 70°C, add 8.2g (0.20 mol molecule) of 97% caustic soda, and stir at the boiling point (94°C) for 6 hours, the N-oxide disappears.
The reaction of step C is completed.

Add 140m of water and PH with about 30g of 62.5% sulfuric acid.
11.0 to 11.5, the crystals cooled to below 10°C are separated in a furnace, washed with a small amount of methanol, thoroughly washed with water, and dried to yield 26.5 g of 2-(2-hydroxy-3,
5-di-t-butylphenyl)benzotriazole was obtained.

Yield: 82.0% Melting point: 150-152°C Comparative Example 7 The same procedure as Example 8 was carried out except that hydroquinone was not used.

yield 25.5 g yield 79.0% melting point 150-152°C

Claims (1)

[Claims] 1. General formula I ▲ Numerical formulas, chemical formulas, tables, etc. are included ▼ I (However, R_1 is a hydrogen or chlorine atom, a lower alkyl group having 1 to 4 carbon atoms, or a lower alkoxyl group having 1 to 4 carbon atoms) , represents a carboxyl group or a sulfonic acid group, R_2 represents a hydrogen or chlorine atom, a lower alkyl group having 1 to 4 carbon atoms, or a lower alkoxyl group having 1 to 4 carbon atoms, and R_3 represents a hydrogen or chlorine atom, a sulfonic acid group having 1 to 4 carbon atoms. 12 alkyl groups, carbon number 1~
4 represents a lower alkoxyl group, a cycloalkyl group, a phenyl group, a phenyl group substituted with an alkyl group having 1 to 8 carbon atoms, a phenoxy group, or a phenylalkyl group having 1 to 4 carbon atoms in the alkyl part, and R_4 is hydrogen. or represents a chlorine atom, a hydroxyl group, or an alkoxyl group having 1 to 4 carbon atoms, and R_5 represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a phenylalkyl group having 1 to 4 carbon atoms in the alkyl portion. ) Using an o-nitroazobenzene derivative shown as a catalyst, a cyclic ketone adjacent to an aromatic ring, an aromatic compound having two or more hydroxy groups as a cocatalyst (promoter), water and a base, and three General formula II characterized by reducing with at least one alcohol selected from the group consisting of primary alcohols and secondary alcohols having the above carbon atoms ▲There are mathematical formulas, chemical formulas, tables, etc.▼ II (However, R_1, R_2, R_3, R_4, R_5 are the same as the general formula I) A method for producing 2-phenylbenzotriazoles. General formula III ▲ Numerical formulas, chemical formulas, tables, etc. R_2 represents hydrogen or a chlorine atom, a lower alkyl group having 1 to 4 carbon atoms, or a lower alkoxyl group having 1 to 4 carbon atoms; R_3 represents hydrogen or a chlorine atom, an alkyl group having 1 to 12 carbon atoms, or a lower alkyl group having 1 to 4 carbon atoms; ~
4 represents a lower alkoxyl group, a cycloalkyl group, a phenyl group, a phenyl group substituted with an alkyl group having 1 to 8 carbon atoms, a phenoxy group, or a phenylalkyl group having 1 to 4 carbon atoms in the alkyl part, and R_4 is hydrogen. or represents a chlorine atom, a hydroxyl group, or an alkoxyl group having 1 to 4 carbon atoms, and R_5 represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a phenylalkyl group having 1 to 4 carbon atoms in the alkyl portion. ) 2-phenylbenzotriazole-N-oxides as a catalyst, cyclic ketones adjacent to the aromatic ring, an aromatic compound having two or more hydroxy groups as a co-catalyst (promoter), and the presence of water and a base. Below, general formula II characterized by reduction with at least one alcohol selected from the group consisting of primary alcohols and secondary alcohols having 3 or more carbon atoms ▲Mathematical formula, chemical formula, table etc.▼II (However, R_1, R_2, R_3, R_4, R_5 are the same as the general formula I) A method for producing 2-phenylbenzotriazoles.