JP7055335B2 - New pyridine compounds and their applications - Google Patents

Description

The present invention relates to a novel pyridine compound which is suitable for an ink composition used for writing tools such as ballpoint pens and markers, has high light resistance, and exhibits a bright yellow to red color, and an application thereof.

Leuco dyes are dyes that change color by reacting with electron-accepting substances (usually acidic substances), and are used for various purposes. In particular, those that change from colorless or pale to vividly colored due to changes in temperature have been applied to heat-sensitive recording materials.

Among them, pyridine-based compounds, particularly triarylpyridine-based compounds, are leuco dyes exhibiting a bright yellow color and are attracting attention, but most of these triarylpyridine-based compounds are light-resistant. It is known that when exposed to natural light or room light for a long period of time, it decomposes relatively quickly and does not exhibit the desired performance. For example, in paragraphs [0028] to [0030] of Japanese Patent Application Laid-Open No. 2016-527345 (Patent Document 1), an ink containing some triarylpyridine compounds as a dye was subjected to a UV light resistance test. As a result, it is clearly stated that the yellow color development disappeared by UV light irradiation for less than 30 minutes.

Patent Document 1 has been studied in order to improve the light resistance of such a triarylpyridine-based compound, but the sufficient light resistance currently required has not been obtained.

Japanese Unexamined Patent Publication No. 2014-218053 (Patent Document 2) proposes a leuco dye of a triarylpyridine-based compound having improved light resistance and color development density. However, since the dye of Patent Document 2 is a triarylpyridine-based compound, it basically lacks light resistance, and although it is described in Patent Document 2 as being improved, further light resistance is required. Further, the color density of the compound of Patent Document 2 is not always sufficient.

Special Table 2016-527345 Gazette Japanese Unexamined Patent Publication No. 2014-218055

The present invention has been made to solve the above problems, and an object of the present invention is to provide a novel pyridine compound having high light resistance and exhibiting a bright yellow to red color, and an application thereof.

As a result of diligent studies to solve the above problems, the inventors of the present invention have found that the novel pyridine compound of the present invention has high light resistance and excellent fluorescent color development, and completed the present invention. ..

［式（１）中、Ｒ^１およびＲ^２は、それぞれ独立して、水素原子、炭素数１～６のアルキル基、炭素数１～６のアシル基または置換もしくは無置換の炭素数６～２０のアリール基であり、Ｒ^３～Ｒ^７は、それぞれ独立して、水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基またはハロゲン原子であり、Ｒ^８～Ｒ^１２は、それぞれ独立して、水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基またはハロゲン原子である。Ａｒは置換または無置換の芳香族複素環基である。］
で表されるものである。 That is, the pyridine compound of the present invention has the following formula (1),

[In the formula (1), R ¹ and R ² are independently hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, acyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted carbon atoms of 6 to 20 carbon atoms. R ³ to R ⁷ are independently hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, alkoxy groups having 1 to 6 carbon atoms or halogen atoms, and R ⁸ to R ¹² are. , Independently, a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom. Ar is a substituted or unsubstituted aromatic heterocyclic group. ]
It is represented by.

R ¹ and R ² in the above formula (1) are preferably an alkyl group having 1 to 6 carbon atoms or an substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

R ¹ and R ² in the above formula (1) are more preferably an ethyl group or a p-tolyl group.

Ar in the above formula (1) may be a thienyl group, a frill group, a thiazolyl group or a pyridinyl group.

The present invention also provides a colorant comprising the pyridine compound described in any of the above.

The present invention further provides an ink composition containing the above colorants.

It is considered that the pyridine compound of the present invention can exhibit high light resistance by having an aromatic heterocyclic group instead of a phenyl group at the 4-position of the pyridine ring, unlike a general triphenylpyridine dye. .. Further, while a general triphenylpyridine dye shows yellow in both visible light and ultraviolet light, the pyridine compound of the present invention shows bright yellow to red, so that it can be used in ink compositions such as ballpoint pens and markers. It can be suitably used.

FIG. 1 is a diagram showing an ultraviolet-visible spectroscopic spectrum of the pyridine compound obtained in Examples 3 to 5.

［式（１）中、Ｒ^１およびＲ^２は、それぞれ独立して、水素原子、炭素数１～６のアルキル基、炭素数１～６のアシル基または置換もしくは無置換の炭素数６～２０のアリール基であり、Ｒ^３～Ｒ^７は、それぞれ独立して、水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基またはハロゲン原子であり、Ｒ^８～Ｒ^１２は、それぞれ独立して、水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基またはハロゲン原子である。Ａｒは置換または無置換の芳香族複素環基である。］ The pyridine compound of the present invention is represented by the following formula (1).

[In the formula (1), R ¹ and R ² are independently hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, acyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted carbon atoms of 6 to 20 carbon atoms. R ³ to R ⁷ are independently hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, alkoxy groups having 1 to 6 carbon atoms or halogen atoms, and R ⁸ to R ¹² are. , Independently, a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom. Ar is a substituted or unsubstituted aromatic heterocyclic group. ]

Independently, R ¹ and R ² in the formula (1) are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an acyl group having 1 to 6 carbon atoms, or an substituted or unsubstituted aryl having 6 to 20 carbon atoms. Represents a group. When R ¹ and R ² are alkyl groups having 1 to 6 carbon atoms, the solubility is improved. On the other hand, when R ¹ and R ² are substituted or unsubstituted aryl groups, the light resistance is improved and the sensitivity to color development / decolorization accompanying a change in pH is increased (or the color development is improved). Therefore, R ¹ and R ² are preferably an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted phenyl group having 6 to 20 carbon atoms, and more preferably both an ethyl group or a p-tolyl group.

Specific examples of the alkyl group having 1 to 6 carbon atoms in R ¹ and R ² of the formula (1) include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and sec. -Butyl group, t-butyl group, n-pentyl group, i-pentyl group, neo-pentyl group, n-hexyl group and the like can be mentioned. Preferably, R ¹ and R ² are alkyl groups having 1 to 4 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group and sec-butyl. Group or t-butyl group.

Specific examples of the acyl group having 1 to 6 carbon atoms in R ¹ and R ² of the formula (1) include a formyl group, an acetyl group, an n-propionyl group, an i-propionyl group and the like. Further, in the present invention, two carboxylic acids bonded to an amino group are condensed to form a cyclic structure having two acyl groups, for example, specifically, a succinimide group is also defined as an acyl group.

Examples of the substituted or unsubstituted aryl group having 6 to 20 carbon atoms in R ¹ and R ² of the formula (1) include a phenyl group and a naphthyl group.

The aryl group having 6 to 20 carbon atoms may have a substituent, and examples of the substituent include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group and sec-butyl. An alkyl group having 1 to 4 carbon atoms such as a group or a t-butyl group, a halogen atom such as F, Cl, Br or I, a nitro group, a cyano group, a hydroxyl group, a carboxylic acid group or an alkoxy group having 1 to 3 carbon atoms Can be mentioned. The substituent is preferably an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 3 carbon atoms from the viewpoint of solubility and color development.

Specific examples of the amino group substituted with R ¹ and R ² in the above formula (1) are shown in the following table. However, it is not limited to these. In the structural formula in the table below, * represents the binding site.

R ³ to R ⁷ , which are substituents of the phenyl group in the formula (1), are independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom. Specifically, the halogen atom is F, Cl, Br or I, and preferably Cl or Br. Alkyl groups having 1 to 8 carbon atoms are methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, i-pentyl group, It may be a neo-pentyl group, an n-hexyl group, an n-octyl group or a 2-ethylhexyl group. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group, an n-butoxy group, an n-pentyloxy group and an n-hexyloxy group. Preferred examples of the alkoxy group having 1 to 6 carbon atoms of R ³ to R ⁷ include a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group and the like. From the viewpoint of light resistance, dissolution stability, and fluorescence color development of the pyridine compound, at least one of R ³ to R ⁷ is preferably an alkoxy group having 1 to 6 carbon atoms. Further, it is more preferable that two of R ³ to R ⁷ are alkoxy groups having 1 to 6 carbon atoms.

R8 to ^R12 , which are substituents of the phenyl group in the formula (1), are basically the same as R3 to ^{R7 ,} and independently have a hydrogen atom, an alkyl group having 1 to ⁸ carbon atoms, and carbon. It is an alkoxy group or a halogen atom having the number 1 to 6. Specifically, the halogen atom is F, Cl, Br or I, and preferably Cl or Br. Alkyl groups having 1 to 8 carbon atoms are methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, t-butyl group, n-pentyl group, i-pentyl group, It may be a neo-pentyl group, an n-hexyl group, an n-octyl group or a 2-ethylhexyl group. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group, an n-butoxy group, an n-pentyloxy group and an n-hexyloxy group. Preferred examples of the alkoxy group having 1 to ⁶ carbon atoms of R8 to ^R12 include a methoxy group, an ethoxy group, an n-propyloxy group, an i-propyloxy group and the like. From the viewpoint of light resistance, dissolution stability, and fluorescence color development of the pyridine compound, at least one of R8 to ^R12 is preferably an alkoxy group having ¹ to 6 carbon atoms. Further, it is more preferable that two of R ⁸ to R ¹² are alkoxy groups having 1 to 6 carbon atoms.

Examples of the substituents (R ³ to R ¹² ) of the phenyl group substituting the 2-position and the 6-position of the pyridine ring in the formula (1) are shown in the following table. The compound examples do not correspond to the numbers of the pyridine compounds in the examples. Substituents are not limited to those described in Table 2.

The pyridine compound of the present invention develops a fluorescent color by adding an electron-accepting substance, and the fluorescent color-developing property is affected by the substitution position of the substituent of the phenyl group to be substituted with the pyridine ring. In the pyridine compound of the present invention, the substitution position of the substituent of the phenyl group to be substituted with the pyridine ring is preferably the 2-position and / or the 4-position.

Ar in the formula (1) represents a substituted or unsubstituted aromatic heterocyclic group. The aromatic heterocyclic group is, for example, a cyclic compound composed of two or more kinds of elements, specifically, a pyrrolyl group, a pyrazolyl group, a thienyl group, a frill group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, and an isoxazolyl group. , Pyrazineyl group, pyridadinyl group or pyrimidinyl group and the like. In the pyridine compound of the present invention, when Ar is a pyridinyl group, a pyrazinyl group, a pyridadinyl group or a pyrimidinyl group which are nitrogen-containing aromatic heterocyclic groups, the light resistance is improved. On the other hand, when Ar is an oxygen-containing or sulfur-containing aromatic heterocyclic group, for example, a thienyl group or a frill group, the maximum absorption wavelength is lengthened and the color is developed in red.

The substituent of Ar in the formula (1) is not particularly limited, but is a carbon such as a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, a sec-butyl group or a t-butyl group. Examples thereof include an alkyl group having the number 1 to 4, a halogen atom such as F, Cl, Br or I, a nitro group, a cyano group, a hydroxyl group, a carboxylic acid group or an alkoxy group having 1 to 3 carbon atoms.

Method for Producing Pyridine Compound of the Present Invention An embodiment of the method for producing a pyridine compound of the present invention will be described. The pyridine compound of the present invention is J.I. Am. Chem. Soc. , 1952, 74 (1), 200-202 and the like. More specifically, in the presence of ammonia or an ammonia generating agent, an acetphenone derivative and a benzaldehyde derivative are heat-condensed under an acid catalyst such as acetic acid to synthesize a cyclized product, and the obtained cyclized product is aminated. It can be obtained by going through an amination step. In the following description of the reaction steps, a synthetic method using a kind of acetophenone derivative will be exemplified, but the present invention is not limited thereto.

[式（２）中、Ｒ^３～Ｒ^７はそれぞれ独立して、水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基またはハロゲン原子である。] (Cyclicase synthesis step)
As an example of the above-mentioned production method, an acetophenone derivative represented by the following formula (2) and an acetophenone derivative are used.

[In the formula (2), R ³ to R ⁷ are independently hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, or halogen atoms. ]

[式（３）中、Ａｒは置換または無置換の芳香族複素環基であり、Ｘはハロゲン原子である。]
酢酸アンモニウム存在下、酢酸中で反応することにより、下記式（４）で表される環化体を合成することができる： The aldehyde derivative represented by the following formula (3) is

[In formula (3), Ar is a substituted or unsubstituted aromatic heterocyclic group, and X is a halogen atom. ]
By reacting in acetic acid in the presence of ammonium acetate, a cyclized product represented by the following formula (4) can be synthesized:

［式（４）中、Ｒ^３～Ｒ^７はそれぞれ独立して、水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基またはハロゲン原子であり、Ａｒは置換または無置換の芳香族複素環基であり、Ｘはハロゲン原子である。］

[In the formula (4), R ³ to R ⁷ are independently hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, alkoxy groups having 1 to 6 carbon atoms or halogen atoms, and Ar is substituted or unsubstituted. It is an aromatic heterocyclic group of, and X is a halogen atom. ]

［式（５）中、Ｒ^１およびＲ^２はそれぞれ独立して水素原子、炭素数１～６のアルキル基、炭素数１～６のアシル基または置換もしくは無置換の炭素数６～２０のアリール基である。］
有機溶媒中で触媒存在下反応させることにより、下記式（６）で表されるピリジン化合物を得ることができる。 (Aminization step)
The obtained cyclized product (4) and the amine compound represented by the following formula (5) were combined with each other.

[In formula (5), R ¹ and R ² are independently hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, acyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted aryls having 6 to 20 carbon atoms, respectively. It is the basis. ]
By reacting in the presence of a catalyst in an organic solvent, a pyridine compound represented by the following formula (6) can be obtained.

［式（６）中、Ｒ^１およびＲ^２はそれぞれ独立して水素原子、炭素数１～６のアルキル基、炭素数１～６のアシル基または置換もしくは無置換の炭素数６～２０のアリール基であり、Ｒ^３～Ｒ^７はそれぞれ独立して、水素原子、炭素数１～８のアルキル基、炭素数１～６のアルコキシ基またはハロゲン原子であり、Ａｒは置換または無置換の芳香族複素環基である。］

[In formula (6), R ¹ and R ² are independently hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, acyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted aryls having 6 to 20 carbon atoms, respectively. Groups, R ³ to R ⁷ are independently hydrogen atoms, alkyl groups with 1 to 8 carbon atoms, alkoxy groups or halogen atoms with 1 to 6 carbon atoms, and Ar is a substituted or unsubstituted aromatic. It is a heterocyclic group. ]

In order for the pyridine compound of the present invention to develop a fluorescent color in the presence of an electron-accepting substance, at ^least one of R3 to ^R7 in the above formula (6) must be an alkoxy group having 1 to 6 carbon atoms. Is preferable, and more preferably two are alkoxy groups having 1 to 6 carbon atoms. The substitution position of the alkoxy group is not particularly limited, but when it is substituted at the ortho-position and / or the para-position from the viewpoint of fluorescence color development and color development stability, vivid fluorescence is developed.

In the cyclized product synthesis step, the charging ratio of the acetophenone derivative represented by the formula (2) and the aldehyde derivative represented by the formula (3) is 2 to 5 mol with respect to 1 mol of the aldehyde derivative. preferable.

In the cyclized product synthesis step, the amount of ammonium acetate added is preferably 5 to 20 times mol with respect to 1 mol of the aldehyde derivative.

In the cyclized product synthesis step, the reaction is preferably carried out at 100 to 120 ° C. in a solvent such as acetic acid without particular limitation. The reaction time is not particularly limited as long as the reaction proceeds, but it is preferably carried out in 2 to 10 hours.

Examples of the catalyst in the aminization step include transition metal catalysts that can be used in the cross-coupling reaction. More specifically, metals such as copper, palladium and nickel or compounds thereof can be mentioned. For example, the copper catalyst is exemplified by copper iodide, copper chloride, copper oxide or copper bromide, and the copper complex is copper thiophen-2-carboxylate (I) or tetrakis (acelut) copper (I) hexafluoro. Phosfert and the like can be exemplified. Examples of the palladium catalyst include tris (dibenzylideneacetone) dipalladium (0), tetrakis (triphenylphosphine) palladium (0), bis (tri-tert-butylphosphine) palladium (0), and bis (triphenylphosphine) palladium. (II) dichloride or [1,1'-bis (diphenylphosphino) ferrocene] palladium (II) dichloride can be exemplified. Furthermore, precursors such as palladium (II) acetate and tris (dibenzylideneacetone) dipalladium (0) can be used by reacting them with ligands such as triphenylphosphine and tri-t-butylphosphine in the system. can. Examples of the nickel catalyst include bis (1,5-cyclooctadiene) nickel (0), bis (triphenylphosphine) nickel dicarbonyl, nickel carbonyl and the like. Although not particularly limited, precursors such as palladium (II) acetate and tris (dibenzylideneacetone) dipalladium (0) may be used as precursors such as triphenylphosphine or tri-t-butylphosphine from the viewpoint of improving reactivity and yield. A palladium catalyst obtained by reacting with a ligand in a system is preferable.

In the aminization step, the reaction is preferably carried out at 100 to 120 ° C. in a solvent such as toluene under a nitrogen stream without particular limitation. The reaction time is not particularly limited as long as the reaction proceeds, but it is preferably carried out in 2 to 10 hours.

The method for extracting the pyridine compound in the present invention is not particularly limited. For example, after neutralizing with a dilute alkaline solution, it is put into a mixed solution of water and methanol to form a slurry, which can be separated from the reaction by-product. Therefore, the easily obtained solid substance is taken out by a method such as filtration. Can be preferred. The method of this filtration is not particularly limited, and for example, a nutche, a pressurized filter, a centrifuge, a filter press, or the like can be used. Further, the obtained pyridine compound may be washed with methanol.

Compared with the conventional triarylpyridine compound, the pyridine compound of the present invention has a structure in which an aromatic heterocyclic group is substituted at the 4-position, has high light resistance and color development, and coexists with an electron-accepting substance such as an organic acid. This causes fluorescent color development. Therefore, it can be suitably used for ink compositions for writing tools such as colorants, ballpoint pens and marker pens.

(Colorant)
The colorant of the present invention contains the pyridine compound of the present invention as a dye component. Further, if necessary, a known dye may be contained. Further, the colorant can be used as a diluting medium such as a liquid medium made of an organic solvent, a liquid medium containing water as a main component, a liquid medium made of water and a hydrophilic organic solvent having an affinity for water, and a resin medium made of a synthetic resin. It can be mixed and used.

The liquid medium composed of the organic solvent or the hydrophilic organic solvent having an affinity for water is not particularly limited, but a liquid medium having high solubility of the pyridine compound of the present invention is preferable. Examples of the highly soluble organic solvent of the pyridine compound of the present invention include ketones such as methyl ethyl ketone.

The colorant is suitably used as a dye, a printing agent, an ink for writing tools, an ink for inkjet, a resin colorant, a colorant for a color filter, and the like, like a colorant containing a conventionally known triphenylpyridine dye. ..

(Ink composition for writing tools)
The ink composition for a writing instrument of the present invention contains at least a colorant containing the pyridine compound of the present invention, a liquid medium, and a resin that dissolves in the liquid medium, and is a writing tool such as a ballpoint pen, a marking pen, or a felt-tip pen. It is preferably used by being filled in. The content of the colorant is preferably 0.5 to 35% by mass, more preferably 2 to 20% by mass, based on the total amount of the ink composition for writing tools. If the content is less than 0.5% by mass, the coloring power and color-developing property of the ink composition for writing tools will be insufficient. On the other hand, if it exceeds 35% by mass, the handwriting will be blurred.

An oil-based ink containing a colorant can be formulated using this ink composition for writing tools, and the handwriting by the writing tool filled with this ink is excellent in color development and light resistance.

Examples of the liquid medium contained in the ink composition for writing tools include solvents such as alcohol-based solvents, polyhydric alcohol-based solvents, glycol ether-based solvents, diether-based solvents, ketone-based solvents and ester-based solvents. The content of the solvent is appropriately set according to the type of writing instrument and the type and content of the dyeing pigment, but is preferably 20 to 97% by mass, preferably 30 to 97% by mass, based on the total amount of the ink composition for writing instruments. It is more preferably 95% by mass.

The alcohol-based solvent is an aliphatic alcohol having 2 or more carbon atoms, and specifically, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 1-pentanol, isoamyl alcohol, s. -Amil alcohol, 3-pentanol, t-amyl alcohol, n-hexanol, methyl amyl alcohol, 2-ethylbutanol, n-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-octanol, 2-ethyl Hexanol, 3,5,5-trimethylhexanol, nonanol, n-decanol, undecanol, n-decanol, trimethylnonyl alcohol, tetradecanol, heptadecanol, cyclohexanol, 2-methylcyclohexanol, benzyl alcohol or 2-phenoxyethanol And so on.

As polyhydric alcohol-based solvents, ethylene glycol, diethylene glycol, 3-methyl-1,3-butanediol, triethylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,5-pentane Examples thereof include polyhydric alcohols having two or more carbons and two or more hydroxy groups in the molecule, such as diols, hexylene glycols or octylene glycols, or derivatives thereof.

As glycol ether-based solvents, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, Diethylene glycol monobutyl ether, Triethylene glycol monobutyl ether, Tetraethylene glycol monobutyl ether, Propylene glycol monomethyl ether, Propylene glycol monoethyl ether, Propylene glycol monopropyl ether, Propylene glycol monobutyl ether, Propylene glycol phenyl ether, Propylene glycol tertiary butyl ether , Dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, tetrapropylene glycol monobutyl ether and the like.

Examples of the diether-based solvent include ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, and dipropylene glycol dimethyl ether.

Specific examples of the ketone solvent include acetone, methyl ethyl ketone, dipropyl ketone, methyl isobutyl ketone, methyl isopropyl ketone, 2-pentanone, 2-hexanone, 2-heptanone, cyclohexanone and the like.

As ester solvents, propylene glycol methyl ether acetate, propylene glycol diacetate, 3-methyl-3-methoxybutyl acetate, propylene glycol ethyl ether acetate, ethylene glycol ethyl ether acetate, butyl formate, isobutyl formate, isoamyl formate, propyl acetate, Butyl acetate, isopropyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, propyl propionate, isobutyl propionate, isoamyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate, methyl isobutyrate, ethyl isobutyrate, iso Propyl butyrate, methyl valerate, ethyl valerate, propyl valerate, methyl isovalerate, ethyl isovalerate, propyl isovalerate, methyl trimethylacetate, ethyl trimethylacetate, propyl trimethylacetate, methyl caproate, ethyl caproate, Propyl caproate, methyl caprylate, ethyl caprylate, propyl caprylate, methyl laurate, ethyl laurate, methyl oleate, ethyl oleate, triglyceride caprylate, tributylacetate citrate, octyl oxystearate, propylene glycol monolithino Examples include rates, methyl 2-hydroxyisobutyrate, 3-methoxybutyl acetate or diesters that do not have a hydroxy group in the molecule.

The ink composition for writing tools contains a resin for improving the fixing property of the ink, preventing the show-through of handwriting, improving the solubility and dispersibility of the dyeing pigment, and adjusting the viscosity. This resin dissolves in the solvent which is the above-mentioned liquid medium. The content of the resin is preferably 0.5 to 35% by mass, preferably 1.0 to 20% by mass, based on the total amount of the ink composition for writing utensils, from the viewpoint of adjusting the viscosity and the writing taste. Is more preferable. If the content is less than 0.5% by mass, the viscosity of the ink composition for writing tools may be insufficient, causing bleeding of handwriting and wear of the pen tip of the ballpoint pen. On the other hand, if it exceeds 35% by mass, the solvent or dye pigment to be contained in the ink composition for writing tools may be insufficient, or the handwriting may be blurred, which may adversely affect the writing quality.

Such resins include ketone resins such as polyether ketones, polyether ether ketones; styrene resins such as polystyrene; polyvinyl acetal resins such as polyvinyl butyral; polyvinylpyrrolidone; rosin-modified maleic acid resins, styrene maleines. Maleic acid-based resins such as acid resins; phenolic resins such as rosin-modified phenolic resins, terpenephenolic resins, alkylphenolic resins; acrylic resins such as styrene-acrylic resins; rosin-based resins; ureaaldehyde-based resins; or cyclohexanone Examples include based resins. Of these, polyvinyl butyral resin is preferable.

The ink composition for writing tools may contain an electron accepting substance, an antioxidant, an ultraviolet absorber, an antifoaming agent and a pH adjuster, if necessary.

By adding the electron-accepting substance, it develops fluorescence when irradiated with UV light. Suitable electron-accepting substances in ink compositions for writing tools are not particularly limited, but generally include organic acids and acidic substances that act like acidic substances in a medium. Specifically, phenols such as bisphenol A, β-naphthol, 4-t-butylphenol, 4,4'-dihydroxydiphenyl sulfone, 4-hydroxy-4'-isopropoxydiphenyl sulfone, and 2,4'-dihydroxydiphenyl sulfone. Compounds, 4-hydroxybenzophenone, dimethyl 4-hydroxyphthalate, methyl 4-hydroxybenzoate, pt-butylbenzoic acid, salicylic acid, 3-t-butylsalicylic acid, 3- (α-methylbenzyl) salicylic acid or 3 , 5-Di-t-butylsalicylic acid and other aromatic carboxylic acids are exemplified. Although not particularly limited, it is preferable to add 0.1 to 3 parts by mass of the electron-accepting substance to 1 part by weight of the pyridine compound of the present invention in the ink composition.

The antioxidant is not particularly limited, but a hindered phenolic antioxidant can be exemplified. More specifically, 2,2'-ethyldenbis (4,6-di-t-butylphenol), 2,2'-ethyldenbis (4-methyl-6-t-butylphenol), 2,2'-ethylidenebis. (4-Ethyl-6-t-butylphenol) or 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane can be mentioned. In the ink composition, it is preferable to add 0.01 to 2 parts by mass of the antioxidant with respect to 1 part by weight of the pyridine compound of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention should not be construed as being limited to these Examples.

(Synthesis of pyridine compound)
(Synthesis example 1: Synthesis of cyclized body 1)
5-bromo-2-pyridinecarboxyaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.) 1.00 g (5.38 mmol) and 4'-methoxyacetophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) 1.62 g (10.8 mmol) in a 50 ml three-necked flask. , 7.17 g (93.0 mmol) of ammonium acetate, 6 g of acetic acid was added, and the mixture was stirred at 120 ° C. for 6 hours. The mixture was allowed to cool to room temperature, 15 ml of hot water at 60 ° C. was added, and the mixture was extracted with toluene. The toluene phase was washed successively with 25 ml of a 6% aqueous sodium hydroxide solution and 25 ml of hot water at 60 ° C. 10 ml of ethanol was added to the recovered toluene phase, and the mixture was allowed to cool overnight and the precipitate was collected by filtration. The precipitate was washed with 10 ml of ethanol and then dried at 60 ° C. to obtain 0.92 g (yield 38.2%) of a white solid as the cyclized body 1 represented by the following formula (7).

Elemental analyzer (EA: 2400II fully automatic elemental analyzer manufactured by Parkin Elmer Japan), 1H-nuclear magnetic resonance device (NMR: JNM-AL300 manufactured by JEOL Ltd.), differential thermal / thermal weight measurement (EA: JM-AL300 manufactured by JEOL Ltd.) TG / DTA: TG / DTA6200) manufactured by SII Nanotechnology, Inc. was measured. The results are shown below. From these results, it was confirmed that the cyclized product 1 had the structure of the chemical formula (7).

Melting point: 145.3 ° C
^{1 1} H NMR (CDCl _3,300 MHz) δ (ppm):
3.93 (6H, s), 6.55 (4H, d), 7.35 (1H, dd), 7.66 (1H, d), 8.03 (4H, d), 8.38 (2H) , S), 8.43 (1H, d)

(Synthesis Example 2: Synthesis of cyclized body 2)
In a 500 ml three-necked flask, 10.0 g (53.8 mmol) of 5-bromo-2-pyridinecarboxyaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.) and 2', 4'-diethoxyacetophenone (manufactured by SIGMA-ALDRICH) 23.9 g ( 115 mmol), 71.7 g (930 mmol) of ammonium acetate, and 60 g of acetic acid were added, and the mixture was stirred at 120 ° C. for 6 hours. The mixture was allowed to cool to room temperature, 150 ml of hot water at 60 ° C. was added, and the mixture was extracted with toluene. The toluene phase was washed successively with 250 ml of a 6% aqueous sodium hydroxide solution and 250 ml of hot water at 60 ° C. 100 ml of ethanol was added to the recovered toluene phase, and the mixture was allowed to cool overnight and the precipitate was collected by filtration. The precipitate was washed with 100 ml of ethanol and then dried at 60 ° C. to obtain 10.0 g (yield 32.9%) of a white solid as the cyclized product 2 represented by the following formula (8).

The obtained white solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the cyclized product 2 had the structure of the chemical formula (8).

Melting point: 148.1 ° C
^{1 1} H NMR (CDCl _3,300 MHz) δ (ppm):
1.49 (12H, t), 4.09 (8H, q), 6.55 (2H, d), 6.61 (2H, dd), 7.75 (1H, d), 7.93 (1H) , D), 8.05 (2H, d), 8.43 (1H, d), 8.79 (1H, d)

(Synthesis Example 3: Synthesis of cyclized body 3)
(Synthesis of 1-chloro-2,4-diethoxybenzene)
Add 12.5 g (86.5 mmol) of 4-chlororesorcinol (manufactured by Tokyo Chemical Industry Co., Ltd.) and 40 g of triethylene glycol monomethyl ether to a 300 ml flask, heat to 70 ° C., and stir until 4-chlororesorcinol is completely dissolved. gone. After visually confirming that 4-chlororesorcinol was completely dissolved, 45.1 g (225 mmol) of ethyl p-toluenesulfonate was added thereto, and then 48.5 g (242 mmol) of a 20% sodium hydroxide aqueous solution was added for 1 hour. It was slowly dropped over. After completion of the dropping, the mixture was stirred for 3 hours, further heated to 80 ° C., and stirred for 1 hour. The mixture was allowed to cool to room temperature, 100 ml of ion-exchanged water was added, and the mixture was stirred for a while. The precipitate was allowed to stand overnight in a refrigerator, the precipitate was collected by filtration, washed with 200 ml of ion-exchanged water, and dried at 40 ° C. to obtain 15.5 g (yield 89.2%) of a yellowish white solid.

(Synthesis of 1-chloro-2,4-diethoxyacetophenone)
15.5 g (77.2 mmol) of 1-chloro-2,4-diethoxybenzene obtained by the above reaction was added to a 100 ml flask, and 60 ml of dichloromethane was added to completely dissolve the mixture. Magnesium sulfate was added to this, dehydrated, and then filtered. The filtrate is added to a 100 ml flask, 10.4 g (78.0 mmol) of aluminum chloride is added with stirring, and after cooling to 10 ° C. under an ice bath, 6.12 g (78.0 mmol) of acetyl chloride is slowly added over 30 minutes. Dropped. After the completion of the dropping, the mixture was stirred for one and a half hours, then poured into 100 g of ice water, and 50.0 g of concentrated hydrochloric acid was added thereto. Further, 100 ml of dichloromethane was added, the dichloromethane phase was recovered using a separatory funnel, neutralized with 100 ml of saturated sodium hydrogen carbonate solution, dehydrated with magnesium sulfate, and the obtained dichloromethane phase was distilled off under reduced pressure using an evaporator. The mixture was removed to obtain 16.5 g (yield 88.1%) of a pale yellow solid.

(Synthesis of cyclized body 3)
5-Bromo-2-pyridinecarboxyaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.) 1.00 g (5.38 mmol) and 1-chloro-2,4-diethoxyacetophenone 2.62 g (10.8 mmol) in a 50 ml three-necked flask. 7.17 g (93 mmol) of ammonium acetate and 6 g of acetic acid were added, and the mixture was stirred at 120 ° C. for 6 hours. The mixture was allowed to cool to room temperature, 15 ml of hot water at 60 ° C. was added, and the mixture was extracted with toluene. The toluene phase was washed successively with 25 ml of a 6% aqueous sodium hydroxide solution and 25 ml of hot water at 60 ° C. 10 ml of ethanol was added to the recovered toluene phase, and the mixture was allowed to cool overnight and the precipitate was collected by filtration. The precipitate was washed with 10 ml of ethanol and then dried at 60 ° C. to obtain 1.06 g (yield 29.7%) of a pale yellow solid as the cyclized product 3 represented by the following formula (9).

The obtained pale yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the cyclized product 3 had the structure of the chemical formula (9).

Melting point: 166.3 ° C
^{1 1} H NMR (CDCl _3,300 MHz) δ (ppm):
1.50 (12H, t), 4.09 (8H, q), 6.59 (2H, s), 7.35 (1H, d), 7.66 (1H, d), 8.00 (2H) , S), 8.39 (2H, s), 8.43 (1H, s)

(Synthesis of cyclized body 4)
In a 200 ml three-necked flask, 5.0 g (26.2 mmol) of 5-bromo-2-thiophenecarboxyaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.) and 11.9 g (manufactured by SIGMA-ALDRICH) of 2', 4'-diethoxyacetophenone (manufactured by SIGMA-ALDRICH). 57.1 mmol), 34.9 g (453 mmol) of ammonium acetate, and 30 g of acetic acid were added, and the mixture was stirred at 120 ° C. for 6 hours. The mixture was allowed to cool to room temperature, 75 ml of hot water at 60 ° C. was added, and the mixture was extracted with toluene. The toluene phase was washed successively with 75 ml of a 6% aqueous sodium hydroxide solution and 75 ml of hot water at 60 ° C. 50 ml of ethanol was added to the recovered toluene phase, and the mixture was allowed to cool overnight and the precipitate was collected by filtration. The precipitate was washed with 50 ml of ethanol and then dried at 60 ° C. to obtain 5.93 g (yield 39.8%) of a pale yellow solid as the cyclized product 4 represented by the following formula (10).

The obtained pale yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the cyclized product 4 had the structure of the chemical formula (10).

Melting point: 142.0 ° C
^{1 1} H NMR (CDCl _3,300 MHz) δ (ppm):
1.47 (12H, t), 4.09 (8H, q), 6.55 (2H, d), 6.61 (2H, dd), 7.08 (1H, d), 7.25 (1H) , D), 8.01 (2H, s), 8.06 (2H, d)

(Synthesis of cyclized body 5)
In a 200 ml three-necked flask, 5.1 g (29.1 mmol) of 5-bromo-2-furancarboxyaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.) and 13.0 g (manufactured by SIGMA-ALDRICH) of 2', 4'-diethoxyacetophenone (manufactured by SIGMA-ALDRICH). 62.4 mmol), 38.8 g (503 mmol) of ammonium acetate, and 30 g of acetic acid were added, and the mixture was stirred at 120 ° C. for 6 hours. The mixture was allowed to cool to room temperature, 75 ml of hot water at 60 ° C. was added, and the mixture was extracted with toluene. The toluene phase was washed successively with 75 ml of a 6% aqueous sodium hydroxide solution and 75 ml of hot water at 60 ° C. 50 ml of ethanol was added to the recovered toluene phase, and the mixture was allowed to cool overnight and the precipitate was collected by filtration. The precipitate was washed with 50 ml of ethanol and then dried at 60 ° C. to obtain 6.01 g (yield 37.4%) of a pale yellow solid as the cyclized product 5 represented by the following formula (11).

The obtained pale yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the cyclized product 5 had the structure of the chemical formula (11).

Melting point: 134.0 ° C
^{1 1} H NMR (CDCl _3,300 MHz) δ (ppm):
1.33 (6H, t), 1.52 (6H, t), 4.07 (8H, q), 5.83 (1H, d), 6.53 (2H, d), 6.61 (2H) , Dd), 6.79 (1H, d), 8.01 (2H, s), 8.38 (2H, d)

(Synthesis of cyclized body 6)
2-Bromo-5-thiazolecarboxyaldehyde (manufactured by SIGMA-ALDRICH) 5.63 g (29.3 mmol) and 2', 4'-diethoxyacetophenone (manufactured by SIGMA-ALDRICH) 13.0 g (manufactured by SIGMA-ALDRICH) in a 300 ml three-necked flask. 62.4 mmol), 39.1 g (507 mmol) of ammonium acetate, and 30 g of acetic acid were added, and the mixture was stirred at 120 ° C. for 6 hours. The mixture was allowed to cool to room temperature, 75 ml of hot water at 60 ° C. was added, and the mixture was extracted with toluene. The toluene phase was washed successively with 75 ml of a 6% aqueous sodium hydroxide solution and 75 ml of hot water at 60 ° C. 50 ml of ethanol was added to the recovered toluene phase, and the mixture was allowed to cool overnight and the precipitate was collected by filtration. The precipitate was washed with 50 ml of ethanol and then dried at 60 ° C. to obtain 5.37 g (yield 32.2%) of a pale yellow solid as the cyclized product 6 represented by the following formula (12).

The obtained pale yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the cyclized product 5 had the structure of the chemical formula (12).

Melting point: 135.2 ° C
^{1 1} H NMR (CDCl _3,300 MHz) δ (ppm):
1.45 (12H, t), 4.09 (8H, q), 6.54 (2H, d), 6.60 (2H, dd), 7.67 (1H, s), 7.95 (2H) , S), 8.09 (2H, d)

(Example 1) Synthesis of pyridine compound 1 3.61 g (8.07 mmol) of the cyclized product obtained in Synthesis Example 1 and 0.59 g (8.07 mmol) of diethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) in a 50 ml three-necked flask. ), Toluene 17 ml, tri-t-butylphosphine 0.19 g (0.94 mmol), palladium (II) acetate 0.07 g (0.31 mmol), sodium-t-butoxide 1.09 g (11.3 mmol). , Filled with toluene. The mixture was heated to 100 ° C., stirred for 5 hours, and then allowed to cool to room temperature. 50 ml of dichloromethane was added and filtered. The solvent was distilled off under reduced pressure, and 10 ml of methanol was added to the residue in the flask to form a slurry. After filtration, the cells were washed with 20 ml of methanol. Toluene (20 ml) was added to the wet cake, heated to 100 ° C. to completely dissolve it, and filtered at hot temperature. The filtrate was allowed to stand in the refrigerator overnight and the crystals were collected by filtration. The mixture was washed with 10 ml of methanol and dried at 60 ° C. overnight to obtain 0.68 g (yield 19.2%) of a yellow solid which is the pyridine compound 1 represented by the following formula (13).

The obtained yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the pyridine compound 1 had the structure of the chemical formula (13).

Melting point: 148.2 ° C
^{1 1} H NMR (CDCl _3,300 MHz) δ (ppm):
1.12 (6H, t), 2.99 (4H, q), 3.93 (6H, s), 6.55 (4H, d), 7.35 (1H, d), 7.66 (1H) , D), 8.03 (4H, d), 8.38 (2H, s), 8.43 (1H, d)

(Measurement of maximum absorption wavelength)
The absorption spectrum of the obtained pyridine compound 1 was measured with an ultraviolet-visible spectrophotometer Pharma Spec UV-1700 (manufactured by Shimadzu Corporation) under the following measurement conditions, and the maximum absorption wavelength λ _max was measured.

As the measurement condition of the absorbance, 10 mg of the sample to be measured is dissolved in 100 ml of a mixed solution adjusted to methanol: 80% acetic acid = 80:20, further diluted 10-fold with the mixed solution, and then the pore diameter is 0.5 μm. The sample solution was obtained by filtering with a solvent-based membrane filter.

The maximum absorption wavelength λ _max of the pyridine compound 1 was as follows.
λ _max = 402.4 nm

(Light resistance test)
The light resistance test of the obtained pyridine compound 1 was performed by light irradiation with a light resistance tester Suntest CPS + (manufactured by Atlas Electric Device Co., Ltd.), and the high performance liquid chromatography Promindence LC-20AT (manufactured by Shimadzu Corporation) was used. It was calculated from the peak area before and after light irradiation.

As the measurement conditions for the light resistance test, 10 mg of the sample to be measured was dissolved in 100 ml of a mixed solution adjusted to methanol: 80% acetic acid = 80:20, further diluted 10-fold with the mixed solution, and then the pore diameter was 0. It was filtered through a 5 μm solvent-resistant membrane filter to prepare a sample solution. 10 ml of this sample solution is added to a 15 ml screw type sample tube, and the screw type sample tube is sealed with a cap. The light intensity of the screw type sample tube is assumed to be light through a window in a light resistance tester (irradiation intensity 30 w / m ² , 300-400 nm). Was irradiated for 10 hours. The sample before light irradiation and the sample after light irradiation were measured by high performance liquid chromatography, and the residual ratio of the pyridine compound was calculated by comparing the area values. The results obtained are shown in Table 18.

High performance liquid chromatography was measured under the following conditions.
Column: L-COLUMNODS2 (4.6 x 250 mm, 5 μm) manufactured by Chemicals Evaluation and Research Institute
Mobile phase: Tetrahydrofuran (HPLC grade manufactured by Wako Pure Chemical Industries, Ltd.): 25 mM ammonium acetate aqueous solution (pH 4) = 70:30
Flow rate: 1.0 ml / min
Column temperature: 40 ° C
Measurement wavelength: 365 nm

(Example 2) Synthesis of pyridine compound 2 4.56 g (8.09 mmol) of the cyclized product 2 obtained in Synthesis Example 2 and 0.59 g (8.09 mmol) of diethylamine (manufactured by Tokyo Chemical Industry Co., Ltd.) in a 50 ml three-necked flask. ), Toluene 17 ml, tri-t-butylphosphine 0.19 g (0.94 mmol), palladium (II) acetate 0.07 g (0.31 mmol), sodium-t-butoxide 1.09 g (11.3 mmol). , Filled with toluene. The mixture was heated to 100 ° C., stirred for 5 hours, and then allowed to cool to room temperature. 50 ml of dichloromethane was added and filtered. The solvent was distilled off under reduced pressure, and 10 ml of methanol was added to the residue in the flask to form a slurry. After filtration, the cells were washed with 20 ml of methanol. Toluene (20 ml) was added to the wet cake, heated to 100 ° C. to completely dissolve it, and filtered at hot temperature. The filtrate was allowed to stand in the refrigerator overnight and the crystals were collected by filtration. The mixture was washed with 10 ml of methanol and dried at 60 ° C. overnight to obtain 0.76 g (yield 21.4%) of a yellow solid which is the pyridine compound 2 represented by the following formula (14).

The obtained yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the pyridine compound 2 has the structure of the chemical formula (14).

Melting point: 150.9 ° C
^{1 1} H NMR (CDCl _3,300 MHz) δ (ppm):
1.12 (6H, t), 1.40 (12H, t), 2.99 (4H, q), 4.17 (8H, q), 6.55 (2H, d), 6.61 (2H) , Dd), 7.35 (1H, d), 7.66 (1H, d), 8.01 (2H, d), 8.38 (2H, s), 8.43 (1H, d)

For the obtained pyridine compound 2, the maximum absorption wavelength was measured in the same manner as in Example 1.
The maximum absorption wavelength λ _max was as follows.
λ _max = 409.7 nm

(Light resistance test)
The obtained pyridine compound 2 was subjected to a light resistance test in the same manner as in Example 1. The results are shown in Table 18.

(Example 3) Synthesis of pyridine compound 3 4.56 g (8.09 mmol) of the cyclized product 2 obtained in Synthesis Example 2, 1.60 g (8.11 mmol) of p, p'-ditrilamine, in a 50 ml three-necked flask. Weigh 17 ml of toluene, 0.19 g (0.94 mmol) of tri-t-butylphosphine, 0.07 g (0.30 mmol) of palladium (II) acetate, and 1.09 g (11.3 mmol) of sodium-t-butoxide, and nitrogen. Was filled. The mixture was heated to 100 ° C., stirred for 5 hours, and then allowed to cool to room temperature. 50 ml of dichloromethane was added and filtered. The solvent was distilled off under reduced pressure, and 10 ml of methanol was added to the residue in the flask to form a slurry. After filtration, the cells were washed with 20 ml of methanol. Toluene (20 ml) was added to the wet cake, heated to 100 ° C. to completely dissolve it, and filtered at hot temperature. The filtrate was allowed to stand in the refrigerator overnight and the crystals were collected by filtration. The mixture was washed with 10 ml of methanol and dried at 60 ° C. overnight to obtain 2.91 g (yield 52.9%) of a yellow solid which is the pyridine compound 3 represented by the following formula (15).

The obtained yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the pyridine compound 3 had the structure of the chemical formula (15).

Melting point: 175.6 ° C
^{1 1} H NMR (CDCl ₃ , 300 MHz) δ (ppm):
1.44 (12H, q), 2.34 (6H, s), 4.09 (8H, q), 6.55 (2H, d), 6.61 (2H, dd), 7.09 (8H) , M), 7.35 (1H, d), 7.66 (1H, d), 8.01 (2H, d), 8.38 (2H, S), 8.43 (1H, d)

For the obtained pyridine compound 3, the maximum absorption wavelength was measured in the same manner as in Example 1.
The maximum absorption wavelength λ _max was as follows. The results are shown in FIG.
λ _max = 410.3 nm

(Light resistance test)
The obtained pyridine compound 3 was subjected to a light resistance test in the same manner as in Example 1. The results are shown in Table 18.

(Example 4) Synthesis of pyridine compound 4 Example 3 except that 4.61 g (8.10 mmol) of the cyclized compound 4 was used instead of the cyclized compound 2 and the drying temperature of the crystals after washing with methanol was set to 30 ° C. The same operation as in the above was carried out to obtain 2.71 g (yield 48.8%) of a yellow solid which is the pyridine compound 4 represented by the following formula (16).

The obtained yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the pyridine compound 4 has the structure of the chemical formula (16).

Melting point: 82.5 ° C
^{1 1} H NMR (CDCl ₃ , 300 MHz) δ (ppm):
1.43 (12H, q), 2.33 (6H, s), 4.08 (8H, q), 6.53 (2H, d), 6.60 (2H, dd), 7.10 (8H) , M), 7.19 (1H, d), 7.27 (1H, d), 7.96 (2H, S), 8.03 (2H, d)

For the obtained pyridine compound 4, the maximum absorption wavelength was measured in the same manner as in Example 1.
The maximum absorption wavelength λ _max was as follows. The results are shown in FIG.
λ _max = 482.4 nm

(Light resistance test)
The obtained pyridine compound 4 was subjected to a light resistance test in the same manner as in Example 1. The results are shown in Table 18.

(Example 5) Synthesis of pyridine compound 5 The same operation as in Example 3 was carried out except that 4.46 g (8.07 mmol) of the cyclized product 5 was used instead of the cyclized product 2, and the following formula (17) was used. 2.89 g (yield 53.5%) of the represented pyridine compound 5 was obtained as a pale yellow solid.

The obtained yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the pyridine compound 5 has the structure of the chemical formula (17).

Melting point: 150.5 ° C
^{1 1} H NMR (CDCl ₃ , 300 MHz) δ (ppm):
1.29 (6H, t), 1.48 (6H, t), 2.31 (6H, s), 4.05 (8H, q), 5.85 (1H, d), 6.51 (2H) , D), 6.59 (2H, dd), 6.81 (1H, d), 7.04 (8H, m), 7.99 (2H, s), 8.03 (2H, d)

For the obtained pyridine compound 5, the maximum absorption wavelength was measured in the same manner as in Example 1.
The maximum absorption wavelength λ _max was as follows. The results are shown in FIG.
λ _max = 479.2 nm

(Light resistance test)
The obtained pyridine compound 5 was subjected to a light resistance test in the same manner as in Example 1. The results are shown in Table 18.

(Example 6) Synthesis of pyridine compound 6 The same operation as in Example 3 was performed except that 4.61 g (8.11 mmol) of the cyclized product 6 was used instead of the cyclized product 2, and the following formula (18) was used. 2.55 g (yield 45.9%) of the represented pyridine compound 6 was obtained as a yellow solid.

The obtained yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the pyridine compound 6 had the structure of the chemical formula (18).

Melting point: 152.4 ° C
^{1 1} H NMR (CDCl ₃ , 300 MHz) δ (ppm):
1.41 (12H, q), 2.35 (6H, s), 4.06 (8H, q), 6.52 (2H, d), 6.59 (2H, dd), 7.24 (8H) , M), 7.69 (1H, s), 7.89 (2H, s), 8.06 (2H, d)

For the obtained pyridine compound 6, the maximum absorption wavelength was measured in the same manner as in Example 1. The maximum absorption wavelength λ _max was as follows.
λ _max = 413.3 nm

(Light resistance test)
The obtained pyridine compound 6 was subjected to a light resistance test in the same manner as in Example 1. The results are shown in Table 18.

(Example 7) Synthesis of pyridine compound 7 The same operation as in Example 3 was carried out except that 5.14 g (8.14 mmol) of the cyclized product 3 was used instead of the cyclized product 2, and the following formula (18) was used. 2.49 g (yield 40.9%) of the represented pyridine compound 7 was obtained as a yellow solid.

The obtained yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The chlorine content was quantified with a chlorine / sulfur analyzer (manufactured by Mitsubishi Chemical Analytech Co., Ltd., product name TOX-2100H). The results are shown below. From these results, it was confirmed that the pyridine compound 7 had the structure of the chemical formula (19).

Melting point: 193.0 ° C
^{1 1} H NMR (CDCl ₃ , 300 MHz) δ (ppm):
1.41 (12H, q), 2.35 (6H, s), 4.06 (8H, q), 6.52 (2H, s), 7.08 (8H, m), 7.35 (2H) , Dd), 7.69 (1H, d), 8.00 (2H, s), 8.39 (2H, s), 8.43 (1H, s)

For the obtained pyridine compound 7, the maximum absorption wavelength was measured in the same manner as in Example 1.
The maximum absorption wavelength λ _max was as follows.
λ _max = 416.8 nm

(Light resistance test)
The obtained pyridine compound 7 was subjected to a light resistance test in the same manner as in Example 1. The results are shown in Table 18.

(Comparative synthesis example 1: Comparative cyclized body 1)
To a 100 ml three-necked flask, add 2.00 g (10.80 mmol) of p-bromobenzaldehyde, 3.24 g (21.6 mmol) of 4'-methoxyacetophenone, and 14.4 g (186 mmol) of ammonium acetate to 12 g of acetic acid, and add 6 at 120 ° C. Stirred for hours. The mixture was allowed to cool to room temperature, 30 ml of hot water at 60 ° C. was added, and the mixture was extracted with toluene. The toluene phase was washed successively with 50 ml of 6% aqueous sodium hydroxide solution and 50 ml of hot water at 60 ° C. 20 ml of ethanol was added to the recovered toluene phase, and the mixture was allowed to cool overnight and the precipitate was collected by filtration. The precipitate was washed with 20 ml of ethanol and then dried at 60 ° C. to obtain 1.75 g (yield 36.4%) of a white solid as the comparative cyclized product 1 represented by the following formula (20).

The obtained white solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the comparative cyclized product 1 had the structure of the chemical formula (20).

Melting point: 133.9 ° C
^{1 1} H NMR (CDCl ₃ , 300 MHz) δ (ppm):
3.93 (6H, s), 6.55 (4H, dd), 7.59 (4H, q), 8.03 (2H, s), 8.06 (4H, d)

(Comparative Example 1) Synthesis of Comparative Pyridine Compound 1 In a 50 ml three-necked flask, 1.75 g (3.92 mmol) of the comparative cyclized product 1 obtained in Comparative Synthesis Example 1, 0.66 g (3.92 mmol) of diphenylamine, and 10 ml of toluene. , Tri-t-butylphosphine 0.09 g (0.45 mmol), palladium (II) acetate 0.03 g (0.14 mmol), sodium-t-butoxide 0.52 g (5.42 mmol), weighed and filled with nitrogen. bottom. The mixture was heated to 100 ° C., stirred for 5 hours, and then allowed to cool to room temperature. 50 ml of dichloromethane was added and filtered. The solvent was distilled off under reduced pressure, and 10 ml of methanol was added to the residue in the flask to form a slurry. After filtration, the cells were washed with 20 ml of methanol. Toluene (20 ml) was added to the wet cake, heated to 100 ° C. to completely dissolve it, and filtered at hot temperature. The filtrate was allowed to stand in the refrigerator overnight and the crystals were collected by filtration. The mixture was washed with 10 ml of methanol and dried at 60 ° C. overnight to obtain 1.21 g (yield 57.5%) of a yellow solid which is the comparative pyridine compound 1 represented by the following formula (21).

The obtained yellow solid was subjected to elemental analysis and 1H-NMR and TG / DTA measurements in the same manner as in Synthesis Example 1. The results are shown below. From these results, it was confirmed that the comparative pyridine compound 1 had the structure of the chemical formula (21).

Melting point: 143.9 ° C
^{1 1} H NMR (CDCl ₃ , 300 MHz) δ (ppm):
3.93 (6H, s), 6.55 (4H, dd), 7.26 (12H, m), 7.57 (2H, d), 8.01 (2H, s), 8.06 (4H) , D)

For the obtained comparative pyridine compound 1, the maximum absorption wavelength was measured in the same manner as in Example 1.
The maximum absorption wavelength λ _max was as follows.
λ _max = 420.9 nm

(Light resistance test)
The obtained comparative pyridine compound 1 was subjected to a light resistance test in the same manner as in Example 1. The results are shown in Table 18.

Table 18 summarizes the light resistance test results of the pyridine compounds 1 to 7 obtained in Examples 1 to 7 and the comparative pyridine compound 1 obtained in Comparative Example 1. In Table 18, the evaluation results of light resistance are × when the residual rate of the pyridine compound after irradiation is less than 50%, Δ when 51 to 80%, and 〇, 91 to 100% when 81 to 90%. The case of is described as ◎.

(Example 8)
The ink compositions 1 to 7 for writing tools were prepared using the pyridine derivatives of Examples 1 to 7, and the ink compositions 1 for comparative writing tools were prepared using the comparative pyridine compound 1 of Comparative Example 1, respectively. The composition of each ink composition is shown in Table 19. In Table 19, numbers other than the composition number column indicate mass%.

In Table 19, polyvinyl butyral BL-1 is a polyvinyl butyral resin manufactured by Sekisui Chemical Co., Ltd., and Hirac 111 is a cyclohexanone-based ketone resin manufactured by Hitachi Kasei Kogyo Co., Ltd. Salicylic acid and 4-hydroxy-4'-isopropoxydiphenyl sulfone used as a color developer are reagents manufactured by Tokyo Chemical Industry Co., Ltd.

The ink composition for writing tools shown in Table 19 is stirred by a dissolver and dispersed, and then an appropriate amount is filled in a marking pen (manufactured by Pilot Corporation) having a felt-tip pen core, and a cap is placed so as to cover the pen core. A marking pen for evaluation was manufactured by fitting. The dry-up property and light resistance were evaluated below using a marking pen and are shown in Table 20. Table 20 also shows the hue of each ink.

(Evaluation of dry-up property of ink composition for writing tools)
The cap of the prepared marking pen was removed, and the pen was left at 25 ° C. and 65% humidity for 1 minute, and then a circle was written on PPC paper by freehand. The cassoulet of the handwriting was evaluated in the following four stages.
Cassoulet was hard to occur: ○
Some cassoulet occurred: △
Cassoulet was easy to occur: ×
It could not be evaluated because the colorant containing marking pen ink did not dissolve :-

(Evaluation of light resistance of ink composition for writing tools)
I wrote a circle on PPC paper freehand with the marking pen I made. This PPC paper was irradiated in the light resistance tester Suntest CPS + (manufactured by Atlas Electric Device Co., Ltd.) for 1 hour at a light intensity (irradiation intensity 30 w / m ² , 300-400 nm) assuming light through a window. .. Changes in writing were evaluated visually.
There is no change in the written circle: ◎
There is almost no change in the written circle: 〇 The color of the written circle is slightly lighter: △
The color of the written circle has faded or partially disappeared: ▲
The color of the written circle has changed and the circle has partially disappeared: ×

As is clear from Table 20, the writing instrument ink compositions 1 to 7 to which the present invention is applied are extremely excellent in light resistance as compared with the comparative writing instrument ink composition 1 to which the present invention is not applied. Was confirmed. Further, the ink compositions 4 and 5 for writing tools to which the present invention was applied showed red color development and fluorescent color development.

Since the pyridine compound of the present invention exhibits high light resistance and color development, it can be suitably used as a colorant used for recording material applications. Further, since the ink composition using the pyridine compound of the present invention has high light resistance, color development property and fluorescent color development property, it can be suitably used for ink compositions for writing tools such as markers.

Claims (4)

A colorant containing a pyridine compound represented by the following general formula (1).

[In the formula (1), R ¹ and R ² are independently hydrogen atoms, alkyl groups having 1 to 6 carbon atoms, acyl groups having 1 to 6 carbon atoms, or substituted or unsubstituted carbon atoms of 6 to 20 carbon atoms. R ³ to R ⁷ are independently hydrogen atoms, alkyl groups having 1 to 8 carbon atoms, alkoxy groups having 1 to 6 carbon atoms or halogen atoms, and R ⁸ to R ¹² are. , Independently, a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a halogen atom. Ar is a thienyl group, a frill group, a thiazolyl group or a pyridinyl group . ] The colorant according to claim 1, wherein R ¹ and R ² in the formula (1) are an alkyl group having 1 to 6 carbon atoms or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms. The colorant according to claim 2, wherein R ¹ and R ² in the formula (1) are an ethyl group or a p-tolyl group. An ink composition containing the colorant according to any one of claims 1 to 3 .

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