JP2010037212A - Method for producing asymmetric azine compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an industrially advantageous method for producing an asymmetric azine compound of high purity, with a simple operation. <P>SOLUTION: The asymmetric azine compound (I) of high purity is obtained by a process comprising washing a mixture of an azine compound (I) represented by formula (I) and an azine compound (II) represented by formula (II) or an azine compound (III), with a 1-15C alcohol. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing an asymmetric azine compound useful as an intermediate for producing a polymerizable liquid crystal compound.

  A specific asymmetric azine compound is an excellent liquid crystal material having characteristics such as a wide temperature range showing a liquid crystal phase, chemical stability and production at a low cost.

As a method for producing an asymmetric azine compound, a method is known in which hydrazine monohydrate is sequentially reacted with different types of benzaldehyde compounds (Patent Document 1).
However, the method for producing an asymmetric azine compound described in this document has a problem that disproportionation to a symmetric azine compound is likely to occur, and the target asymmetric azine compound cannot be obtained in high yield.

  In addition, it is known that the disproportionation reaction is promoted by an acid. When an asymmetric azine compound having an acidic group such as a hydroxyl group or a carboxyl group is produced, the disproportionation reaction is further facilitated. For this reason, there is a problem that the yield of the target asymmetric azine compound is further reduced due to an increase in the amount of symmetric azine compound produced.

  In order to solve such a problem, Patent Document 2 discloses an asymmetric method in which a benzaldehyde compound is reacted with hydrazine monohydrate to obtain a hydrazone compound, and then different types of benzaldehyde compounds are reacted in the presence of amines. A method for producing an azine compound has been proposed. According to this method, it is said that a high-purity asymmetric azine compound can be obtained with less by-product of the symmetric azine compound.

  However, in the example of Patent Document 2, the reaction mixture was purified by column chromatography, and then recrystallization was repeated twice to obtain the target asymmetric azine compound. Although the purity of the obtained target product was high, The operation was complicated and the yield was not necessarily high.

In addition, as a method for producing an asymmetric azine compound having an acidic group such as a hydroxyl group or a carboxyl group, it may be possible to use a benzaldehyde compound in which a hydroxyl group, a carboxyl group or the like is protected with a protective group, but the reaction selectivity is improved. This is disadvantageous in terms of cost.
Therefore, development of a method for producing an asymmetric azine compound having a high purity by a simpler method in an industrially advantageous manner is desired.
JP 54-87688 A JP-A-10-59919

  This invention is made | formed in view of the situation of this prior art, and makes it a subject to provide the method of manufacturing a highly pure asymmetric azine compound industrially advantageously by simple operation.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors obtained a reaction mixture containing an asymmetric azine compound and a symmetric azine compound by sequentially reacting hydrazine monohydrate with different types of benzaldehyde compounds, When this reaction mixture is washed with a specific alcohol solvent, the symmetrical azine compound can be selectively removed. As a result, it has been found that a highly pure asymmetric azine compound can be obtained in high yield, and the present invention has been completed.

Thus, according to the present invention, a method for producing the following asymmetric azine compounds (azine compounds (I)) (1) to (5) is provided.
(1) Formula (I)

[Wherein, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ , X ⁸ and X ⁹ may each independently have a hydrogen atom, a halogen atom or a substituent. An alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms which may have a substituent, a cyano group, a nitro group, —OR ² , —O—C (═O) —R ² , —C (═O) —OR ² , —O—C (═O) —OR ² , —NR ⁴ —C (═O) —R ² , —C (═O) —N (R ² ) (R ³ ), Or -OC (= O) -N (R < ² >) (R < ³ >) is represented. Here, R ² and R ³ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted alkenyl group having 2 to 10 carbon atoms. Represents a group. When R ² and R ³ are an alkyl group or an alkenyl group, the alkyl group and alkenyl group include —O—, —S—, —O—C (═O) —, —C (═O) —O. —, —O—C (═O) —O—, —NR ⁵ —C (═O) —, —C (═O) —NR ⁵ —, —NR ⁵ —, or —C (═O) — It may be interposed (except when two or more of —O— and —S— are adjacent to each other). R ⁴ and R ⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
R ¹ represents a hydroxyl group, a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, an alkenyloxycarbonyl group having 2 to 10 carbon atoms, an acryloyloxycarbonyl group, or a methacryloyloxycarbonyl group.
However, the following formula (X)

(Wherein X ^{1 to} X ⁵ represent the same meaning as in formula (I)), and a group represented by formula (XI)

(Wherein, R ¹ , X ^{6 to} X ⁹ represent the same meaning as in formula (I)) are not the same. An azine compound (I) represented by the formula:
Formula (II)

(Wherein X ^{1 to} X ⁵ represent the same meaning as in formula (I).)
An azine compound (II) represented by the formula (III)

(In the formula, X ^{6 to} X ⁹ and R ¹ represent the same meaning as in formula (I).) The mixture containing the azine compound (III) represented by the formula (I) is washed with an alcohol having 1 to 15 carbon atoms. The manufacturing method of azine compound (I) characterized by including the process to do.

(2) The azine compound (I), the azine compound (II), and the azine compound (III) are represented by formulas (I) to (III), respectively, X ¹ , X ² , X ⁴ , X ⁵ , X ⁶ , X ⁷ , X ⁸ and X ⁹ are hydrogen atoms, and X ³ is a halogen atom, a cyano group, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted carbon number 2 The method for producing the azine compound (I) according to the above (1), which is a compound having a -10 alkenyl group or —OR ² (R ² represents the same meaning as described above).

(3) The azine compound (I), the azine compound (II), and the azine compound (III) are represented by formulas (I) to (III), respectively, X ¹ , X ² , X ⁴ , X ⁵ , X ⁶ , X ⁷ , X ⁸ and X ⁹ are hydrogen atoms, X ³ is a fluorine atom, and R ¹ is a hydroxyl group, The method for producing azine compound (I) according to (1) above .

(4) The method for producing azine compound (I) according to (1), wherein the alcohol is an alcohol having 1 to 3 carbon atoms.
(5) A mixture containing the azine compound (I), the azine compound (II) and the azine compound (III) comprises hydrazine and the formula (1)

(Wherein X ^{1 to} X ⁵ represent the same meaning as in formula (I).)
The aldehyde compound (1) represented by formula (2),

(In the formula, X ^{6 to} X ⁹ and R ¹ represent the same meaning as in formula (I).)
The reaction mixture obtained by reacting the aldehyde compound (2) represented by the formula (wherein the aldehyde compound (1) and the aldehyde compound (2) are not the same), described in (1) above A process for producing the azine compound (I).

  According to the production method of the present invention, a high-purity asymmetric azine compound (azine compound (I)) can be obtained in a high yield by a simple operation without requiring complicated operations such as column purification and recrystallization after completion of the reaction. Obtainable.

Hereinafter, the present invention will be described in detail.
The production method of the azine compound (I) of the present invention includes the azine compound (azine compound (I)) represented by the formula (I), the azine compound (azine compound (II)) represented by the formula (II), And a step of washing the mixture containing the azine compound represented by formula (III) (azine compound (III)) with an alcohol having 1 to 15 carbon atoms.

  Examples of the alcohol having 1 to 15 carbon atoms used for washing include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butyl alcohol, amyl alcohol, 1-hexanol, 2-hexanol, 1 -Octanol etc. are mentioned. Among these, in this invention, it is preferable to use C1-C3 alcohol. Examples of the alcohol having 1 to 3 carbon atoms that are preferably used include methanol, ethanol, 1-propanol, and 2-propanol.

  The amount of alcohol used is usually 0.5 to 10 parts by weight, preferably 1.5 to 3 parts by weight, based on 1 part by weight of the mixture.

In Formula (I), Formula (II), and Formula (III), X ^{1 to} X ⁹ are each independently a hydrogen atom, a halogen atom, or a C 1-10 alkyl that may have a substituent. Group, optionally substituted alkenyl group having 2 to 10 carbon atoms, cyano group, nitro group, —OR ² , —O—C (═O) —R ² , —C (═O) —OR ² , —O—C (═O) —OR ² , —NR ⁴ —C (═O) —R ² , —C (═O) —N (R ² ) (R ³ ), or —O—C (= O) —N (R ² ) (R ³ ).

Examples of the halogen atom for X ^{1 to} X ⁹ include a fluorine atom, a chlorine atom, and a bromine atom.
Examples of the alkyl group having 1 to 10 carbon atoms which may have a substituent of X ^{1 to} X ⁹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl. Group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group and the like.

Examples of the alkenyl group having 2 to 10 carbon atoms which may have a substituent of X ^{1 to} X ⁹ include a vinyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, 1-pentenyl group, 3-pentenyl group, 1-hexenyl group and the like can be mentioned.

  Examples of the substituent of the alkyl group having 1 to 10 carbon atoms which may have the substituent and the alkenyl group having 2 to 10 carbon atoms which may have the substituent include a fluorine atom, a chlorine atom and a bromine atom. A halogen atom; an alkoxy group such as a methoxy group and an ethoxy group; and the like.

R ² and R ³ each independently represent a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted alkenyl group having 2 to 10 carbon atoms. . Examples of the alkyl group having 1 to 10 carbon atoms that may have a substituent and the alkenyl group having 2 to 10 carbon atoms that may have a substituent of R ² and R ³ include the above X ^{1 to} X ⁹ . The thing similar to what was illustrated is mentioned.

When R ² and R ³ are an alkyl group or an alkenyl group, the alkyl group and alkenyl group include —O—, —S—, —O—C (═O) —, —C (═O) —O. —, —O—C (═O) —O—, —NR ⁵ —C (═O) —, —C (═O) —NR ⁵ —, —NR ⁵ —, or —C (═O) — It may be interposed. However, the case where two or more of -O- and -S- are adjacent to each other is excluded.

R ⁴ and R ⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms of R ⁴ and R ⁵ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, t-butyl group, n -A pentyl group, n-hexyl group, etc. are mentioned.

R ¹ represents a hydroxyl group, a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, an alkenyloxycarbonyl group having 2 to 10 carbon atoms, an acryloyloxycarbonyl group, or a methacryloyloxycarbonyl group.

Examples of the alkoxycarbonyl group having 1 to 10 carbon atoms of R ¹ include a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an isopropoxycarbonyl group, an n-butoxycarbonyl group, a t-butoxycarbonyl group, and n-pentyloxy. A carbonyl group etc. are mentioned.

Examples of the alkenyloxycarbonyl group having 2 to 10 carbon atoms of R ¹ include a vinyloxycarbonyl group, an allyloxycarbonyl group, a 1-propenyloxycarbonyl group, an isopropenyloxycarbonyl group, a 1-butenyloxycarbonyl group, and 1-pentenyl. Examples thereof include an oxycarbonyl group, a 3-pentenyloxycarbonyl group, a 1-hexenyloxycarbonyl group, and a 2-ethylhexylcarbonyloxy group.

  However, the group represented by the formula (X) and the group represented by the formula (XI) are not the same.

Among these, in the present invention, the azine compound (I), the azine compound (II), and the azine compound (III) are represented by formulas (I) to (III), respectively, X ¹ , X ² , X ⁴ to X ⁹ is a hydrogen atom, X ³ is a halogen atom, a cyano group, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted alkenyl group having 2 to 10 carbon atoms. Or -OR ² (R ² represents the same meaning as described above) is preferable, X ¹ , X ² , X ^{4 to} X ⁹ are hydrogen atoms, X ³ is a fluorine atom, More preferably, R ¹ is a hydroxyl group compound.

  In the present invention, preferred specific examples of the azine compound (I) include the following.

  In the present invention, the mixture containing the azine compound (I), the azine compound (II) and the azine compound (III) comprises hydrazine and the formula (1)

(Wherein X ^{1 to} X ⁵ represent the same meaning as in formula (I)), and then reacted with aldehyde compound (1).

(Wherein X ^{6 to} X ⁹ and R ¹ represent the same meaning as in formula (I)), and is preferably a reaction mixture obtained by reacting aldehyde compound (2) represented by formula (I). However, the aldehyde compound (1) and the aldehyde compound (2) are not the same.

  The production method for obtaining the mixture of the azine compounds of the formula (I) to the formula (III) and the production method of the azine compound of the formula (I) are described in detail below.

  First, an excess of hydrazine (hydrazine monohydrate) and an aldehyde compound (1) are reacted in a solvent such as ethanol to obtain a compound of formula (IV)

(In the formula, X ^{1 to} X ⁵ represent the same meaning as in formula (I).) A reaction solution containing the hydrazone compound (IV) represented by formula (I) is obtained.
The amount of hydrazine and aldehyde compound (1) to be charged is usually 1 to 10 mol, preferably 2 to 5 mol, of hydrazine with respect to 1 mol of aldehyde compound (1).
The reaction temperature is usually from 0 ° C to the reflux temperature of the solvent, preferably from 10 to 30 ° C.
Although depending on the reaction scale, the reaction time is usually several minutes to 24 hours, preferably 1 to 10 hours.

  After completion of the reaction, a solvent insoluble in water such as dichloromethane and chloroform is added to the reaction solution, and the excess hydrazine is removed by washing with a saturated aqueous sodium bicarbonate solution and water.

Next, without isolating the hydrazone compound (IV), the reaction mixture is reacted with the aldehyde compound (2).
The charged amount of the hydrazone compound and the aldehyde compound (2) is usually 1.0 to 1.5 mol, preferably 1.0 to 1.2 mol of the aldehyde compound (1) with respect to 1 mol of the hydrazone compound (IV). It is.

  The reaction is preferably performed in the presence of amines. As amines to be used, secondary amines or tertiary amines are preferable, and tertiary amines are particularly preferable. Tertiary amines include trialkylamines such as triethylamine, trimethylamine, and tributylamine; aromatic tertiary amines such as N, N-dimethylaniline and N, N-diethylaniline; cyclic tertiary amines such as pyridine; Can be mentioned. Among these, trialkylamines such as triethylamine are particularly preferable.

The usage-amount of amines is 0.01-20 mol normally with respect to 1 mol of aldehyde compounds (1), Preferably it is 0.1-10 mol.
The amines may be added to the system when the hydrazone compound (IV) and the aldehyde compound (2) are reacted, or may be added at the stage of the post-treatment of the reaction between the hydrazine and the aldehyde compound (1). The hydrazone compound (IV) and the aldehyde compound (2) are preferably added to the system when they are reacted.

The reaction temperature is usually from 0 ° C to the reflux temperature of the solvent, preferably from 10 to 30 ° C.
Although depending on the reaction scale, the reaction time is usually 15 minutes to 24 hours, preferably 1 to 10 hours.

  After the completion of the reaction, the precipitated crystals are collected by filtration, washed with n-hexane or the like as necessary, and then washed with an alcohol having 1 to 15 carbon atoms as described later to obtain the target azine. Compound (I) can be obtained with high purity.

  As a method for washing a mixture containing azine compound (I), azine compound (II) and azine compound (III) with an alcohol having 1 to 15 carbon atoms, a predetermined amount of alcohol was added to the mixture, and the whole volume was stirred. Then, the method of filtering is mentioned.

The stirring temperature, the stirring time, the number of washings and the like depend on the type of azine compound used, the type of alcohol having 1 to 15 carbon atoms used, the reaction scale, etc., but the target azine compound (I) can be obtained with high purity and high yield. What is necessary is just to set suitably so that it may be obtained.
That is, the stirring temperature, the stirring time, and the number of washings are appropriately combined according to the type and amount of alcohol used so that only azine compound (II) and azine compound (III) can be washed and removed most selectively. do it.

The stirring temperature is usually 5 to 60 ° C, preferably 15 to 50 ° C, more preferably 20 to 45 ° C. If the stirring temperature is too low, azine compound (II) and azine compound (III) cannot be selectively removed by washing, and the content ratio of azine compound (I) cannot be increased. If the stirring temperature is too high, the azine compound (I) may be washed away and the yield may be reduced.
The stirring time is usually 1 minute to 1 hour, preferably about 5 to 40 minutes.

  The number of washings is usually 1 to 3, preferably 1 or 2 times. If the number of washings is large, the operation becomes complicated, and even the target azine compound (I) may be washed away and the yield may be reduced.

  After completion of the stirring, the target product can be obtained by filtering the crystals by suction filtration or the like, washing with a solvent such as hexane as necessary, and drying the solvent.

  The content ratio of azine compound (I), azine compound (II), and azine compound (III) can be analyzed by high performance liquid chromatography.

  According to the production method of the present invention, a high-purity asymmetric azine compound can be obtained in high yield by a simple operation without requiring complicated operations such as column purification and recrystallization after completion of the reaction.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited at all by these.
In the following, 1- (4-fluorobenzylidene) -2- (4′-hydroxybenzylidene) hydrazone is an azine compound (I-1) and 1,2-bis (4-fluorobenzylidene) hydrazone is an azine compound. (II-1) and 1,2-bis (4-hydroxybenzylidene) hydrazone are referred to as azine compound (III-1).

Example 1 Synthesis of Azine Compound (I-1) (Part 1)

  Hydrazine monohydrate 1014 g was dissolved in ethanol 1024 g to obtain a uniform solution. To this solution, 838.3 g of 4-fluorobenzaldehyde (1-1) was added dropwise at room temperature (23 ° C.) under a nitrogen stream, and the mixture was further stirred at room temperature (23 ° C.) for 30 minutes. To the reaction mixture, 2095 g of chloroform and 1255 g of saturated aqueous sodium hydrogen carbonate were added for extraction, and the organic layer was separated.

  The organic layer was washed with 1255 g of saturated sodium bicarbonate solution, 83.8 g of triethylamine was added, and 824.9 g of 4-hydroxybenzaldehyde (2-1) was added with stirring. After the addition was completed, the mixture was further heated at room temperature (23 ° C.). Stir for 2 hours. The precipitated crystals were collected by filtration and washed with 660 g of n-hexane to obtain a pale yellow solid.

  To this pale yellow solid was added 3353.3 g of ethanol, and the mixture was stirred at room temperature (23 ° C.) for 20 minutes, followed by filtration. The solid collected by filtration was washed with 660 g of n-hexane to obtain 936 g of a solid containing compound (I-1). The yield was 57.2%.

  When the obtained solid was analyzed by high performance liquid chromatography, the production ratio of azine compound (II-1), azine compound (I-1), and azine compound (III-1) was determined as azine compound (II-1). : Azine compound (I-1): Azine compound (III-1) = 2.8: 92.9: 4.3.

Example 2 Synthesis of Azine Compound (I-1) (Part 2)
In Example 1, instead of adding 3353.3 g of ethanol and stirring at room temperature (23 ° C.) for 20 minutes, 3353.3 g of ethanol was added and stirred for 20 minutes at 40 ° C., followed by filtration. Except for adding 3353.3 g and stirring at 40 ° C. for 20 minutes, the same operation as in Example 1 was performed to obtain 739 g of a solid containing the azine compound (I-1). The yield was 45.2%.

  When the obtained solid was analyzed by high performance liquid chromatography, the production ratio of azine compound (II-1), azine compound (I-1), and azine compound (III-1) was determined as azine compound (II-1). : Azine compound (I-1): Azine compound (III-1) = 1.8: 97.2: 1.0.

Comparative Example 1
In Example 1, the solid (yield 71.5%) before washing with ethanol was analyzed by high performance liquid chromatography. As a result, compound azine (II-1), azine compound (I-1), And the production ratio of azine compound (III-1) was azine compound (II-1): azine compound (I-1): compound (III-1) = 3.7: 87.3: 9.0. .
The results of Examples 1 and 2 and Comparative Example 1 are summarized in Table 1.

  Compared to Comparative Example 1 in which ethanol was not washed, Example 1 washed once with ethanol at 23 ° C. and Example 2 washed twice with ethanol at 40 ° C. gave the desired asymmetric azine compound in high purity. . Moreover, although Example 2 with many washing | cleaning frequency becomes a yield low, compared with Example 1, a desired asymmetric azine compound is obtained with higher purity.

Claims (5)

Formula (I)

[Wherein, X ¹ , X ² , X ³ , X ⁴ , X ⁵ , X ⁶ , X ⁷ , X ⁸ and X ⁹ may each independently have a hydrogen atom, a halogen atom or a substituent. An alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms which may have a substituent, a cyano group, a nitro group, —OR ² , —O—C (═O) —R ² , —C (═O) —OR ² , —O—C (═O) —OR ² , —NR ⁴ —C (═O) —R ² , —C (═O) —N (R ² ) (R ³ ), Or represents O—C (═O) —N (R ² ) (R ³ ). Here, R ² and R ³ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 10 carbon atoms, or an optionally substituted alkenyl group having 2 to 10 carbon atoms. Represents a group. When R ² and R ³ are an alkyl group or an alkenyl group, the alkyl group and alkenyl group include —O—, —S—, —O—C (═O) —, —C (═O) —O. ^{-, - O-C (=} O) -O -, - NR 5 -C (= O) -, - C (= O) -NR 5 -, - NR 5 -, or C (= O) - is interposed (However, the case where two or more of —O— and —S— are adjacent to each other is excluded). R ⁴ and R ⁵ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
R ¹ represents a hydroxyl group, a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, an alkenyloxycarbonyl group having 2 to 10 carbon atoms, an acryloyloxycarbonyl group, or a methacryloyloxycarbonyl group.
However, the following formula (X)

(Wherein X ^{1 to} X ⁵ represent the same meaning as in formula (I)), and a group represented by formula (XI)

(Wherein, R ¹ , X ^{6 to} X ⁹ represent the same meaning as in formula (I)) are not the same. An azine compound (I) represented by the formula:
Formula (I1)

(Wherein X ^{1 to} X ⁵ represent the same meaning as in formula (I).)
An azine compound (II) represented by the formula (III)

(In the formula, X ^{6 to} X ⁹ and R ¹ represent the same meaning as in formula (I).)
A mixture containing the azine compound (III) represented by
The manufacturing method of azine compound (I) characterized by including the process of wash | cleaning with C1-C15 alcohol. In the formulas (I) to (III), the azine compound (I), the azine compound (II), and the azine compound (III) are each represented by X ¹ , X ² , X ⁴ , X ⁵ , X ⁶ , X ⁷ , X ⁸ and X ⁹ are hydrogen atoms, X ³ is a halogen atom, a cyano group, an optionally substituted alkyl group having 1 to 10 carbon atoms, and an optionally substituted carbon atom having 2 to 10 carbon atoms. The method for producing an azine compound (I) according to claim 1, wherein the compound is an alkenyl group, or —OR ² (R ² represents the same meaning as in formula (I)). In the formulas (I) to (III), the azine compound (I), the azine compound (II), and the azine compound (III) are each represented by X ¹ , X ² , X ⁴ , X ⁵ , X ⁶ , X ⁷ , X ^The method for producing an azine compound (I) according to claim 1, wherein ⁸ and X ⁹ are hydrogen atoms, X ³ is a fluorine atom, and R ¹ is a hydroxyl group.   The method for producing an azine compound (I) according to claim 1, wherein the alcohol is an alcohol having 1 to 3 carbon atoms. A mixture containing the azine compound (I), the azine compound (II) and the azine compound (III) is obtained by combining hydrazine with the formula (1)

(Wherein X ^{1 to} X ⁵ represent the same meaning as in formula (I).)
The aldehyde compound (1) represented by formula (2),

(In the formula, X ^{6 to} X ⁹ and R ¹ represent the same meaning as in formula (I).)
The reaction mixture obtained by reacting aldehyde compound (2) represented by the formula (wherein aldehyde compound (1) and aldehyde compound (2) are not the same)). Production method of azine compound (I).