JP2012211087A - Method of producing 3-(2-alkoxyphenyl)-5-pyrazolylamide oxime intermediate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of directly producing a 3-(2-alkoxyphenyl )-5-pyrazolylamide oxime derivative without 3-(2-alkoxyphenyl)-5-amidinyl pyrazole that is an unstable imidate intermediate.SOLUTION: The method includes: mixing acetonitrile with C1-C3 alcohol in the presence of hydrochloric acid; adding 3-(2-alkoxyphenyl)-5-amino pyrazole to the mixture of the acetonitrile with the alcohol and then stirring the resultant mixture; and adding hydroxylamine to the mixture.

Description

  The present invention relates to a method for producing a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime intermediate, and more specifically, 1H-pyrazolo [1,5-b] [1,2], which is a coupler of an azomethine dye. , 4] This invention relates to a method for producing a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime intermediate, which is a useful intermediate in the synthesis of triazole.

  The heat-sensitive sublimation transfer method uses a thermal transfer film that carries a dye layer in which a sublimable dye is dissolved or dispersed in a binder resin. The thermal transfer film is layered on the image-receiving film and is transferred to a heating device such as a thermal head. By applying energy according to the above, the sublimation dye contained in the dye layer on the thermal transfer film is transferred to the image receiving film to form an image.

  This heat-sensitive sublimation transfer method can control the amount of dye transfer in dot units according to the amount of energy applied to the thermal transfer film, so that it is excellent in forming a gradation image and has advantages such as easy formation of characters, symbols, etc. have. The image obtained by such a thermal transfer method can form a high-quality image similar to a silver salt photograph, and accordingly, there is an extremely high demand for prevention of image quality degradation due to factors such as light, heat, and humidity of the image. Development of various sublimation dyes for improving image storage stability has been made.

  For example, as a thermal transfer dye having excellent transferability and storage stability, Patent No. 3013137 (Patent Document 1) and Patent No. 3078308 (Patent Document 2) include 1H-pyrazolo [5,1-C] [1 , 2,4] An azomethine compound having a structure in which a triazole ring is a coupler and a pyridyl group is bonded to the coupler via a nitrogen atom is disclosed. Japanese Patent No. 2840901 (Patent Document 3) uses a 1H-pyrazolo [1,5-b] [1,2,4] triazole ring as a coupler, and a phenylamino group is bonded to the coupler via a nitrogen atom. An azomethine compound of structure is disclosed. Further, JP-A-5-239367 (Patent Document 4) discloses that a pyridyl group is added to a 1H-pyrazolo [1,5-b] [1,2,4] triazole ring coupler which is a combination of both. An azomethine compound having a structure bonded to a coupler via a nitrogen atom is disclosed.

  Although the azomethine dyes disclosed in the above patents 3013137 and 3078308 are excellent in light resistance, the 1H-pyrazolo [5,1-C] [1,2,4] triazole ring is used as a coupler. There is a cost problem. The azomethine dye described in Japanese Patent No. 2840901 using a 1H-pyrazolo [1,5-b] [1,2,4] triazole ring compound as a raw material coupler has a merit that it can be produced at a relatively low cost. May be insufficient.

On the other hand, the dye described in JP-A-5-239367, which is a combination of 1H-pyrazolo [1,5-b] [1,2,4] triazole ring coupler and a pyridyl group, can be produced at low cost and has light resistance. Also has the advantage of being superior. In particular, a phenyl group introduced as a substituent R ₆ of the 1H-pyrazolo [1,5-b] [1,2,4] triazole ring proposed in JP-A-5-239367 (9, (10, 11, 22, 112) is excellent in that the color tone of the pigment is close to the required color gamut.

However, the compound described in JP-A-5-239367, particularly a compound into which an unsubstituted pyridyl group is introduced as the substituent R ₆ of the triazole ring is excellent in terms of production cost and light resistance, but the reaction of the coupling reaction The rate is low, and the yield is about 20% as described in JP-A-5-239367.

Patent No. 3013137 Japanese Patent No. 3078308 Japanese Patent No. 2840901 JP-A-5-239367

  In the previous application (Japanese Patent Application No. 2009-85637, filing date: March 31, 2009), the present inventors have added nitrogen to the 1H-pyrazolo [1,5-b] [1,2,4] triazole ring. In the azomethine compound in which the pyridine ring is bonded via an atom, the azomethine compound having a specific substituent is excellent in terms of light resistance and manufacturing cost, has high purity, and has a high sensitivity and solubility when used as a dye. It also proposes to be excellent. And in that prior application, the present inventors made 2-benzoylacetonitrile by reacting benzoic acid ester compound as a starting material with acetonitrile in the presence of potassium t-butoxide, and then obtained 2-benzoylacetonitrile. Reacting benzoylacetonitrile with hydrazine to obtain 3- (2-alkoxyphenyl) -5-aminopyrazole intermediate, which was reacted with imidate hydrochloride to form an amidine compound, and then hydroxylamine was reacted with it. Then, the resulting amide oxime derivative is reacted with p-toluenesulfonic acid chloride and heated to reflux in the presence of pyridine to give 1H-pyrazolo [1,5-b] [1, It is also proposed that a 2,4] triazole coupler is obtained.

  In the above reaction, when synthesizing a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative via 3- (2-alkoxyphenyl) -5-amidinylpyrazole using acetonitrile as a starting material, Since the reaction yield of 3- (2-alkoxyphenyl) -5-amidinylpyrazole, which is a reaction intermediate, was low, purification was necessary. However, since this reaction intermediate is unstable with respect to moisture and the like, it must be handled with care when used in the next reaction step.

  Inventors of the present invention now use 3- (2-alkoxyphenyl) -5-aminopyrazole as a starting material, a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative, and 1H-pyrazolo [1, When synthesizing 5-b] [1,2,4] triazole couplers, the 3- (2-alkoxyphenyl) -5-amidinylpyrazole, which is an unstable imidate intermediate, is directly synthesized. -(2-alkoxyphenyl) -5-pyrazolylamide oxime derivative and synthesis method capable of synthesizing target compound 1H-pyrazolo [1,5-b] [1,2,4] triazole coupler I found. The present invention is based on this finding.

  Therefore, the object of the present invention is to directly produce 3- (2-alkoxyphenyl) -5-pyrazolyl without going through the unstable imidate intermediate 3- (2-alkoxyphenyl) -5-amidinylpyrazole. It is to provide a method capable of producing an amide oxime derivative.

  Another object of the present invention is an intermediate useful in synthesizing an azomethine compound, which is a dye compound, from a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative obtained by the above production method. It is to provide a method capable of synthesizing 1H-pyrazolo [1,5-b] [1,2,4] triazole couplers.

A process for producing a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative from 3- (2-alkoxyphenyl) -5-aminopyrazole according to the present invention, comprising:
Mixing acetonitrile and C1-C3 alcohol in the presence of hydrochloric acid,
3- (2-alkoxyphenyl) -5-aminopyrazole is added to the mixture of acetonitrile and alcohol and stirred, then
Hydroxylamine is added to the mixture to produce a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative.

  Moreover, in the aspect of this invention, it is preferable that the said alcohol is methanol or ethanol.

  Further, in an embodiment of the present invention, the addition of the 3- (2-alkoxyphenyl) -5-aminopyrazole is carried out by adding a triethylamine solution, anhydrous sodium acetate solution of 3- (2-alkoxyphenyl) -5-aminopyrazole, Or it is preferable to carry out as a sodium acetate trihydrate solution.

  In the embodiment of the present invention, the 3- (2-alkoxyphenyl) -5-aminopyrazole may be 3- (2-methoxyphenyl) -5-aminopyrazole, 3- (2-ethoxysiphenyl) -5. It is preferably -aminopyrazole, 3- (2-propoxyphenyl) -5-aminopyrazole, or 3- (2-isopropoxyphenyl) -5-aminopyrazole.

  In another aspect of the present invention, a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative obtained by the above production method is also provided.

（式中、Ｒ_１は炭素数Ｃ１〜３の直鎖または分枝を有するアルキル基である。） In another embodiment of the present invention, a 1H-pyrazolo [1,5-b] [1,2,4] triazole coupler is produced using a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative. How to
The 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative obtained by the above production method is reacted with p-toluenesulfonic acid chloride and heated to reflux in the presence of pyridine to obtain the following formula (I To obtain a 1H-pyrazolo [1,5-b] [1,2,4] triazole coupler represented by formula (1).

(In the formula, R ₁ is a linear or branched alkyl group having ₁ to 3 carbon atoms.)

（式中、Ｒ_２およびＲ_３はそれぞれ独立して、炭素数Ｃ２〜４のアルキル基を示す。）

（式中、Ｒ_１は、炭素数Ｃ１〜３の直鎖または分枝を有するアルキル基であり、Ｒ_２およびＲ_３は、それぞれ独立して、炭素数Ｃ２〜４のアルキル基を示す。） In another embodiment of the present invention, the method for producing an azomethine compound is a 1H-pyrazolo [1,5-b] [1] represented by the above formula (I) obtained by the above production method. , 2,4] A triazole coupler and a pyridyldiamino derivative represented by the following formula (II) are reacted with an oxidizing agent in the presence of a base to obtain an azomethine compound represented by the following formula (III). It is characterized by comprising.

(In the formula, R ₂ and R ₃ each independently represent an alkyl group having 2 to 4 carbon atoms.)

(In the formula, R ₁ is a linear or branched alkyl group having 1 to ₃ carbon atoms, and R ₂ and R ₃ each independently represents an alkyl group having ₂ to 4 carbon atoms.)

  Furthermore, in another aspect of the present invention, there is also provided a thermal transfer recording dye comprising the azomethine compound obtained by the above production method.

  In the present invention, when producing a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative from 3- (2-alkoxyphenyl) -5-aminopyrazole, acetonitrile and alcohol are added in the presence of hydrochloric acid. By adding 3- (2-alkoxyphenyl) -5-aminopyrazole to the mixture of acetonitrile and alcohol and stirring, and then adding hydroxylamine to the mixture The 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative can be directly produced without going through 3- (2-alkoxyphenyl) -5-amidinylpyrazole, which is a simple imidate intermediate.

（式中、Ｒ_１は、炭素数Ｃ１〜３の直鎖または分枝を有するアルキル基であり、Ｒ_２およびＲ_３は、それぞれ独立して、炭素数Ｃ２〜４のアルキル基を示す。） <3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative>
As described above, the 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative is 1H-pyrazolo [1,5-b] [1] which is a coupler material of an azomethine compound represented by the following formula (IV) , 2,4] is a material useful as an intermediate in the synthesis of a triazole ring coupler.

(In the formula, R ₁ is a linear or branched alkyl group having 1 to ₃ carbon atoms, and R ₂ and R ₃ each independently represents an alkyl group having ₂ to 4 carbon atoms.)

  In the present invention, 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative is prepared by mixing acetonitrile and alcohol in the presence of hydrochloric acid, and adding 3- (2-alkoxy) to the mixture of acetonitrile and alcohol. Prepared by adding phenyl) -5-aminopyrazole and stirring, then adding hydroxylamine to the mixture. In the present invention, as in the prior art, 3- (2-alkoxyphenyl) -5-aminopyrazole is allowed to act on imidate hydrochloride to produce 3- (2-alkoxyphenyl) -5-amidinylpyrazole, When 3- (2-alkoxyphenyl) -5-amidinylpyrazole is reacted with hydroxylamine to produce a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative, it is a reaction intermediate. Since the reaction yield of 3- (2-alkoxyphenyl) -5-amidinylpyrazole was low, it was necessary to allow hydroxylamine to act after purification, but 3- (2-alkoxyphenyl) -5 -Since amidinylpyrazole is unstable with respect to moisture and the like, handling was required when proceeding to the next step reaction. According to the production method of the present invention, as described above, from 3- (2-alkoxyphenyl) -5-aminopyrazole, 3- (2-alkoxyphenyl) -5-amino, which is a directly unstable imidate intermediate, is used. A 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative can be obtained directly without going through dinylpyrazole. Moreover, according to the manufacturing method of this invention, the yield of the target product 3- (2-alkoxyphenyl) -5-pyrazolyl amide oxime derivative can be improved. Rather than synthesizing the target product using the purified imidate intermediate, the target product is synthesized directly without going through the imidate intermediate as in the present invention. It was surprising that the yield of) -5-pyrazolylamide oxime derivatives was improved.

  In the above reaction step, the addition of 3- (2-alkoxyphenyl) -5-aminopyrazole to the mixture of acetonitrile and alcohol is preferably performed at an ice temperature.

  Moreover, as alcohol to be used, methanol or ethanol can be used conveniently. In addition, 3- (2-alkoxyphenyl) -5-aminopyrazole is added by dissolving 3- (2-alkoxyphenyl) -5-aminopyrazole in a suitable solvent to form a 3- (2-alkoxyphenyl) solution. It is preferable to stir the -5-aminopyrazole solution dropwise by adding a mixture of acetonitrile and alcohol at ice temperature. Although it does not restrict | limit especially as a solvent, In this invention, a triethylamine, anhydrous sodium acetate, or a sodium trihydrate solution etc. can be used conveniently.

（式中、Ｒはメチル基、プロピル基等のアルキル基であり、Ｒ_１は、炭素数Ｃ１〜３の直鎖または分枝を有するアルキル基を示す。） A 3- (2-alkoxyphenyl) -5-aminopyrazole used as a starting material for the production of a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative is, for example, as shown in the following synthesis scheme: A benzoic acid ester compound as a starting material is reacted with acetonitrile in the presence of potassium t-butoxide to synthesize a compound of the following formula (V).

(In the formula, R represents an alkyl group such as a methyl group or a propyl group, and R ₁ represents a linear or branched alkyl group having ₁ to 3 carbon atoms.)

  The hydrazine to be reacted with the 2-alkoxybenzoylacetonitrile of the above formula (V) is preferably added to the reaction system at a concentration of 1.0 to 1.1 mol / l.

（Ｒ_１は、炭素数Ｃ１〜３の直鎖または分枝を有するアルキル基を示す。） Next, by reacting 2-alkoxybenzoylacetonitrile obtained as described above with hydrazine, 3- (2-alkoxyphenyl) -5-aminopyrazole represented by the following formula (VI) can be obtained. it can.

(R ₁ represents a linear or branched alkyl group having ₁ to 3 carbon atoms.)

In the present invention, 3- (2-alkoxyphenyl) -5-aminopyrazole is 3- (2-methoxyphenyl), wherein R ₁ is a linear or branched alkyl group having ₁ to 3 carbon atoms. ) -5-aminopyrazole, 3- (2-ethoxycyphenyl) -5-aminopyrazole, 3- (2-propoxyphenyl) -5-aminopyrazole, or 3- (2-isopropoxyphenyl) -5-amino Pyrazole can be preferably used. Among these, 3- (2-ethoxysiphenyl) -5-aminopyrazole and 3- (2-propoxyphenyl) -5-aminopyrazole can be preferably used. As described later, when the 6-position of the pyrazolotriazole mother nucleus in synthesizing the azomethine dye is an ethoxyphenyl group or a propoxyphenyl group, the solubility and light resistance of the dye are further improved. More preferred R ₁ is an ethyl group.

（Ｒ_１は、炭素数Ｃ１〜３の直鎖または分枝を有するアルキル基を示す。） <1H-pyrazolo [1,5-b] [1,2,4] triazole coupler>
The 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative represented by the following formula (VII) produced as described above is reacted with p-toluenesulfonic acid chloride and heated in the presence of pyridine. By refluxing, a 1H-pyrazolo [1,5-b] [1,2,4] triazole coupler represented by the following formula (I) can be obtained.

(R ₁ represents a linear or branched alkyl group having ₁ to 3 carbon atoms.)

（式中、Ｒ_２およびＲ_３は、それぞれ独立して、炭素数Ｃ２〜４のアルキル基を示す。）

<Azomethine compound>
1H-pyrazolo [1,5-b] [1,2,4] triazole coupler represented by the above formula (I) and a pyridyldiamine derivative represented by the following formula (II) in the presence of a base, By reacting with an oxidant and coupling, 1H-pyrazolo [1,5-b] [1,2,4] triazole ring represented by the following formula (III) is bonded to pyridine via a nitrogen atom. An azomethine compound to which a ring is bonded can be synthesized. This reaction is performed, for example, within 40 ° C. under water cooling for about 1 hour. The obtained azomethine compound is excellent not only in terms of production cost and light resistance but also in terms of hue sensitivity and solubility.

(In the formula, R ₂ and R ₃ each independently represents an alkyl group having 2 to 4 carbon atoms.)

The pyridyldiamine derivative represented by the above formula (II) is prepared by, for example, dropping a dialkylamine into a solution obtained by dissolving 6-chloro-3-nitro-2-picoline and potassium carbonate in acetonitrile, and stirring the oil layer. The compound b is obtained by separating. Next, as shown in the following scheme, palladium-carbon was added to the obtained ethanol solution of compound b and reacted with hydrogen gas at 1 atm. Then, the reaction solution was filtered, and dioxane hydrochloride was added to the filtrate. In addition, the hydrochloride compound of the following formula (VIII) can be obtained by stirring. Thus, an azomethine compound synthesized using a pyridyldiamine derivative in which R ₂ and R ₃ are all ethyl, propyl, or butyl groups is not only excellent in terms of production cost and light resistance but also in hue. It is also excellent from the viewpoint of sensitivity and solubility.

  The above-mentioned azomethine compound is useful as a heat-sensitive thermal transfer material. For example, the azomethine compound represented by the above formula (III) can be used as a magenta dye for sublimation thermal transfer, and can be suitably used in combination with other known yellow dyes, cyan dyes, other dyes and the like. In addition to the magenta dye, a plurality of dye layers such as yellow, cyan, and black can be provided on the substrate in the surface order to form a thermal transfer sheet. In addition to the plurality of dye layers, a transferable protective layer may be provided in the surface order. In addition, you may provide black of a heat-meltable ink layer further. Conventionally known dyes for sublimation type thermal transfer such as yellow, cyan, and black, and heat-meltable dyes can be used.

  The present invention will be described in more detail with reference to examples, but the present invention is not limited to the examples.

Example 1
<Preparation of 3- (2-ethoxyphenyl) -5-aminopyrazole>
To a 1000 ml four-head flask, 100 g of ethyl 2-ethoxybenzoate (0.52 mol), 500 ml of toluene and 21.1 g of acetonitrile (0.52 mol) were added and stirred in an ice bath. Thereafter, 57.7 g of potassium tert-butoxide (0.52 mol) was added over about 10 minutes. The reaction solution was in a white slurry state. Thereafter, the reaction system was returned to room temperature and stirred for 1 hour. When 100 ml of water was dropped into the reaction system in the water bath over 3 minutes, the reaction solution was separated into two layers. The aqueous layer was recovered, the oil layer was washed twice with 50 ml of water, and the wash water was also recovered as an aqueous layer.
When the obtained aqueous layer was neutralized to about pH 1 with 50 ml (0.55 mol) of 11.1M concentrated hydrochloric acid in a water bath, crystals were precipitated. This was filtered and the crystals were dried at 60 ° C. overnight to obtain 57.2 g (0.32 mol) of the target compound A1. The yield was 59%, and the purity was 94% by HPLC simple area ratio. A synthesis scheme is shown below.

  Next, 89.0 g of compound A1 (0.47 mol) and 90 ml of methanol were added to a 500 ml four-head flask. At that time, the reaction system was in a slurry state although the solution was colored. Next, 0.282 g of acetic acid (0.0048 mol) was added to the reaction system, and then 23.5 g of hydrazine hydrate (0.47 mol) was dropped into the flask over 5 minutes, followed by 3 hours. Heating to reflux was performed. Thereafter, the reaction solution was recovered under reduced pressure at 50 ° C. using a rotary evaporator, dissolved in 300 ml of ethyl acetate, and separated using 100 ml of saturated sodium bicarbonate water. Then, it dried using the saturated salt solution, and concentrated the oil layer at 50 degreeC with the rotary evaporator, and obtained 3- (2-ethoxyphenyl) -5-aminopyrazole of brown oily form. When this compound was analyzed by HPLC, the purity was 95.77% (calculated by the simple area method).

<Synthesis of 3- (2-ethoxyphenyl) -5-pyrazolylamide oxime derivative>
To 3.08 g (75 mmol) of acetonitrile, 4.11 g (129 mmol) of methanol was added and cooled to 0 ° C. Then, 3.99 g (112.6 mmol) of hydrochloric acid gas was introduced into the reaction system and stirred as it was at 0 ° C. overnight. Thereafter, 10.2 ml of methanol was added to the reaction system, 18.71 g (50 mmol) of 3- (2-ethoxyphenyl) -5-aminopyrazole obtained above, 10.2 ml of methanol, and 17.08 g (168.8 mmol) of triethylamine. The reaction solution was added dropwise to a mixed solution consisting of) and stirred at room temperature overnight.
Subsequently, 5.21 g (74.97 mmol) of hydroxylamine was added to the mixed solution to which the reaction solution was dropped, and the mixture was stirred overnight at room temperature. Thereafter, 80 ml of water was added to precipitate crystals from the solution and collected by filtration to obtain the target compound, 3- (2-ethoxyphenyl) -5-pyrazolylamide oxime derivative. The obtained compound was 8.90 g, and the yield based on 3- (2-ethoxyphenyl) -5-aminopyrazole was 77%.

Example 2
A 3- (2-ethoxyphenyl) -5-pyrazolylamide oxime derivative was obtained in the same manner as in Example 1 except that triethylamine was changed to anhydrous sodium acetate (13.84 g, 168.8 mmol). The obtained compound was 7.85 g, and the yield was 68%.

Example 3
A 3- (2-ethoxyphenyl) -5-pyrazolylamide oxime derivative was obtained in the same manner as in Example 1 except that triethylamine was changed to sodium acetate trihydrate (22.96 g, 168.8 mmol). The obtained compound was 7.63 g, and the yield was 66%.

Comparative Example 1
To 3.08 g (75 mmol) of acetonitrile, 4.11 g (129 mmol) of methanol was added and cooled to 0 ° C. Then, 3.99 g (112.6 mmol) of hydrochloric acid gas was introduced into the reaction system and stirred as it was at 0 ° C. overnight. Thereafter, the crystals precipitated in the reaction system were collected by filtration to obtain an imidate compound. The obtained imidate compound was 4.93 g, and the yield was 60%.

  In a four-head flask, 94 g (0.46 mol) of 3- (2-ethoxyphenyl) -5-aminopyrazole obtained above, 500 ml of methanol, and 15.71 g (152.3 mmol) of triethylamine were added. In the reaction system, 50.39 g (0.46 mol) of the imidate compound obtained above was added to the reaction system. In the reaction system, a solid precipitated. The reaction system was stirred at room temperature for 30 minutes, and when the reaction system was monitored by HPLC, it was confirmed that 3- (2-ethoxyphenyl) -5-amidinylpyrazole was produced at a simple area ratio of 76%. It was confirmed that the starting material, 3- (2-ethoxyphenyl) -5-aminopyrazole, disappeared to a simple area ratio of about 4%.

  Next, a solution consisting of 34.5 g of hydroxylamine hydrochloride (0.46 mol), 44.4 g of 28% sodium methylate methanol solution (0.23 mol), and 350 ml of methanol prepared separately in the above reaction system was prepared. What was filtered was dripped in about 5 minutes in the water bath. Thereafter, the reaction system was stirred for 5 hours under heating and reflux (65 ° C.). The reaction was allowed to cool to room temperature and stirred overnight (12.5 hours). Thereafter, when 2.4 L of water was added to the reaction solution, a solid was precipitated from the reaction solution to form a slurry. This slurry was filtered, and the resulting crystals were suspended in 40 ml of methanol for 1 hour in a heated reflux. Thereafter, the mixture was allowed to cool while stirring. When cooled to room temperature, the mixture is stirred while cooling in an ice bath to precipitate crystals from the solution and collected by filtration to give the desired compound, 3- (2-ethoxyphenyl) -5-pyrazolylamide oxime derivative Got. The obtained compound was 8.09 g, and the yield was 70%.

  In Examples 1 to 3, the 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative was directly obtained without going through the unstable imidate intermediate, but in Comparative Example 1, the imidate intermediate was isolated. Because of this, two-step operation was required.

  In Example 1, the yield of the final product based on acetonitrile as the starting material was 51.3% (38.5 mmol / 75 mmol × 100), and the imidate intermediate was purified as in Comparative Example. It was confirmed that the yield of the final product was improved as compared with the yield of the final product (60% × 70% = 42%).

Claims (8)

A method for producing a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative from 3- (2-alkoxyphenyl) -5-aminopyrazole,
Mixing acetonitrile and C1-C3 alcohol in the presence of hydrochloric acid,
3- (2-alkoxyphenyl) -5-aminopyrazole is added to the mixture of acetonitrile and alcohol and stirred, then
A method, wherein hydroxylamine is added to the mixture to produce a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative.   The method of claim 1, wherein the alcohol is methanol or ethanol.   The addition of 3- (2-alkoxyphenyl) -5-aminopyrazole is performed as a triethylamine solution, anhydrous sodium acetate solution, or sodium acetate trihydrate solution of 3- (2-alkoxyphenyl) -5-aminopyrazole. The method according to claim 1, wherein the method is performed.   The 3- (2-alkoxyphenyl) -5-aminopyrazole is 3- (2-methoxyphenyl) -5-aminopyrazole, 3- (2-ethoxysiphenyl) -5-aminopyrazole, 3- (2- The method according to any one of claims 1 to 3, which is propoxyphenyl) -5-aminopyrazole or 3- (2-isopropoxyphenyl) -5-aminopyrazole.   The 3- (2-alkoxyphenyl) -5-pyrazolyl amide oxime derivative obtained by the manufacturing method as described in any one of Claims 1-4. A method for producing a 1H-pyrazolo [1,5-b] [1,2,4] triazole coupler using a 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative,
A 3- (2-alkoxyphenyl) -5-pyrazolylamide oxime derivative obtained by the method according to any one of claims 1 to 4 is reacted with p-toluenesulfonic acid chloride in the presence of pyridine. A method comprising: obtaining 1H-pyrazolo [1,5-b] [1,2,4] triazole coupler represented by the following formula (I) by heating under reflux:

(In the formula, R ₁ is a linear or branched alkyl group having ₁ to 3 carbon atoms.) A method for producing an azomethine compound, the 1H-pyrazolo [1,5-b] [1,2,4] triazole coupler represented by the formula (I) obtained by the production method according to claim 6 And an pyridyldiamino derivative represented by the following formula (II) with an oxidizing agent in the presence of a base to obtain an azomethine compound represented by the following formula (III) And the method.

(In the formula, R ₂ and R ₃ each independently represent an alkyl group having 2 to 4 carbon atoms.)

(In the formula, R ₁ is a linear or branched alkyl group having 1 to ₃ carbon atoms, and R ₂ and R ₃ each independently represents an alkyl group having ₂ to 4 carbon atoms.)   A dye for thermal transfer recording, comprising the azomethine compound obtained by the production method according to claim 7.