JP2009013290A - Azo compound or its salt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new azo compound exhibiting a high color concentration or its salt. <P>SOLUTION: The present invention provides the azo compound represented by formula (I) or its salt. In the formula (I), R<SP>1</SP>to R<SP>4</SP>are each independently a hydrogen atom, a saturated aliphatic hydrocarbon group or a carboxyl group. R<SP>5</SP>to R<SP>12</SP>are each independently a hydrogen atom, a halogen atom, a saturated aliphatic hydrocarbon group, an alkoxyl group, carboxyl group, sulfo group, sulfamoyl group, or an N-substituted sulfamoyl group. At least one of R<SP>13</SP>and R<SP>14</SP>is H, cyano group, carbamoyl group, or an N-substituted carbamoyl group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an azo compound useful as a dye or a salt thereof.

Conventionally, dyes such as azo compounds have been used for color display using reflected light or transmitted light in various fields (for example, fiber materials, liquid crystal display devices, etc.), and have, for example, a pyridone ring. Azo compounds are also known (Patent Documents 1 to 4, etc.). More specifically, Patent Documents 1 and 2 disclose a dye in which one biphenyl skeleton (biphenylene group) and two pyridone rings are connected by two azo groups, and Patent Document 3 discloses a phenyl group and phenylene. A dye in which a group and a pyridone ring are linked by two azo groups is disclosed, and Patent Document 4 discloses a dye in which a phenyl group and a pyridone ring are linked by an azo group. In these patent documents 1 to 3, there is no description about the color density of these pigments. On the other hand, the structure of the dye disclosed in Patent Document 4 is completely different from the azo compound of the present invention or a salt thereof described in detail below.
German Patent Application Publication No. 3416327 U.S. Pat. No. 3,979,378 JP 51-64536 Japanese Patent Publication No.7-88633

  In recent years, with respect to the color density and hue of dyed products, demands from customers have become strict, and a novel azo compound or a salt thereof having a particularly high color density has been demanded. Accordingly, an object of the present invention is to provide a novel azo compound or a salt thereof exhibiting a high color density.

  As a result of intensive studies by the present inventors to further improve the color density of an azo compound or a salt thereof, a compound having a pyridone ring connected to both ends of a biphenyl skeleton via an azo group or a salt thereof exhibits a high color density. I found out. From such knowledge, the azo compound of the present invention or a salt thereof that can achieve the above-mentioned object is represented by the formula (I). The azo compound represented by the formula (I) or a salt thereof may be abbreviated as “azo compound (I)” below. Similarly, a compound represented by another chemical formula or a salt thereof may be abbreviated.

In formula (I), R ^{1 to} R ⁴ each independently represents a hydrogen atom, a C _1-10 saturated aliphatic hydrocarbon group or a carboxyl group.
R ^{5 to} R ¹² are each independently a hydrogen atom, halogen atom, C _1-10 saturated aliphatic hydrocarbon group, halogenated C _1-10 saturated aliphatic hydrocarbon group, C _1-8 alkoxyl group, carboxyl Represents a group, a sulfo group, a sulfamoyl group, or an N-substituted sulfamoyl group.
R ¹³ and R ¹⁴ each independently represents a hydrogen atom, a cyano group, a carbamoyl group, or an N-substituted carbamoyl group.
In the present invention, C _ab means that the carbon number is a or more and b or less.

In formula (I), preferably at least one of R ^{5 to} R ¹² is an N-substituted sulfamoyl group. More preferably, at least one of R ^{5 to} R ⁸ and at least one of R ^{9 to} R ¹² is an N-substituted sulfamoyl group, and at least one of R ⁵ and R ⁸ and at least one of R ⁹ and R ¹² More preferably, one is an N-substituted sulfamoyl group. As the N- substituted sulfamoyl group, -SO ₂ NHR ¹⁵ group (R ¹⁵ is, C _1-10 saturated aliphatic hydrocarbon group, C _1-8 C _1-10 saturated aliphatic hydrocarbon alkoxyl group is substituted Group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms) is preferable. By having an N-substituted sulfamoyl group, preferably a —SO ₂ NHR ¹⁵ group, the azo compound of the present invention or a salt thereof can have both water solubility and oil solubility. In formula (I), preferably, at least one of R ¹³ and R ¹⁴ is a cyano group. The azo compound of the present invention having a cyano group or a salt thereof can exhibit a particularly high color density. And at least one of R ¹³ and R ¹⁴ is a —CON (R ¹⁶ ) R ¹⁷ group (wherein R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, a C _1-10 saturated aliphatic hydrocarbon group, A C _1-10 saturated aliphatic hydrocarbon group substituted by a C _1-8 alkoxyl group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or 2 to 10 carbon atoms Those representing an acyl group are also preferred azo compounds or salts thereof of the present invention.
The azo compound or salt thereof of the present invention includes tautomers thereof in addition to those represented by the formula (I).

  The azo compound or a salt thereof of the present invention exhibits a high color density and is useful as a pigment used in, for example, a fiber material or a liquid crystal display device.

  The azo compound or salt thereof of the present invention is characterized by having a pyridone ring via an azo group at both ends of the biphenyl skeleton as represented by the formula (I). The pyridone ring part includes not only the enol type represented by the formula (I) but also a keto type. Due to such a structure, the azo compound of the present invention or a salt thereof exhibits a high color density. Moreover, the azo compound or its salt of this invention is excellent in the solubility (especially oil solubility) to a solvent in the preferable aspect, and is very suitable also for the color display using transmitted light. The solvent has low volatility such as hydroxycarboxylic acid esters (such as ethyl lactate), hydroxyketones (such as diacetone alcohol), ethers (such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate). A water-soluble solvent is selected.

Hereinafter, the formula (I) will be described in detail. In formula (I), R < ¹ > -R < ⁴ > represents a hydrogen atom, a _C1-10 saturated aliphatic hydrocarbon group, or a carboxyl group. The saturated aliphatic hydrocarbon group for R ^{1 to} R ⁴ may be linear, branched or cyclic. The carbon number of the saturated aliphatic hydrocarbon group does not include the carbon number of the substituent. The carbon number is 1-10 normally, Preferably it is 2-8, More preferably, it is 3-6. Examples of the saturated aliphatic hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group.

In formula (I), R ^{5 to} R ¹² are each independently a hydrogen atom, a halogen atom (preferably a fluorine atom, a chlorine atom or a bromine atom), a C _1-10 saturated aliphatic hydrocarbon group (this C _{1 -10} saturated aliphatic hydrocarbon group including a halogen atom bonded thereto), C _1-8 alkoxyl group, carboxyl group, sulfo group, sulfamoyl group, or N-substituted sulfamoyl group.

As in the case of R ^{1 to} R ⁴ , the saturated aliphatic hydrocarbon group for R ^{5 to} R ¹² may be linear, branched or cyclic, and the carbon number is usually 1 to 10, preferably Is 2-8, more preferably 3-6. Specific examples of the saturated aliphatic hydrocarbon group for R ^{5 to} R ¹² are the same as those for R ^{1 to} R ⁴ . The saturated aliphatic hydrocarbon group of R ^{5 to} R ¹² may be substituted with a halogen atom, preferably a fluorine atom. Specific examples of the halogenated saturated aliphatic hydrocarbon group include a trifluoromethyl group.

Carbon number of the alkoxyl group of R < ⁵ > -R < ¹² > is 1-8 normally, Preferably it is 1-4. Examples of the alkoxyl group include a methoxy group, an ethoxy group, an isopropoxy group, an n-propoxy group, an n-butoxy group, an isobutoxy group, a sec-butoxy group, and a tert-butoxy group.

The N-substituted sulfamoyl group of R ^{5 to} R ¹² is, for example, an N-monosubstituted sulfamoyl group and can be represented by the formula —SO ₂ NHR ¹⁵ . This R ¹⁵ is a C _1-10 saturated aliphatic hydrocarbon group (including a C _1-10 saturated aliphatic hydrocarbon group bonded with a C _1-8 alkoxyl group), an aryl group having 6 to 20 carbon atoms. , An aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms.

The saturated aliphatic hydrocarbon group for R ¹⁵ may be linear, branched or cyclic. The carbon number of the saturated aliphatic hydrocarbon group does not include the carbon number of the substituent, and the number is usually 1 to 10, preferably 6 to 10. Examples of the saturated aliphatic hydrocarbon group represented by R ¹⁵ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a methylbutyl group (1, 1,3,3-tetramethylbutyl group), methylhexyl group (1,5-dimethylhexyl group etc.), ethylhexyl group (2-ethylhexyl group etc.), cyclopentyl group, cyclohexyl group, methylcyclohexyl group (2-methyl) A cyclohexyl group), a cyclohexyl alkyl group, and the like. As described above, the saturated aliphatic hydrocarbon group for R ¹⁵ may be substituted with a substituent such as a C _1-8 (preferably C _1-4 ) alkoxyl group. Examples of the substituted saturated aliphatic hydrocarbon group include a propoxypropyl group (3- (isopropoxy) propyl group and the like).

The aryl group for R ¹⁵ may be unsubstituted or may have a substituent such as a saturated aliphatic hydrocarbon group or a hydroxyl group. The carbon number of the aryl group is counted including the carbon number of the substituent, and is usually 6 to 20, preferably 6 to 10. Examples of these aryl groups include unsubstituted or substituted phenyl groups such as a phenyl group, a hydroxyphenyl group (such as 4-hydroxyphenyl group), and a trifluoromethylphenyl group (such as 4-trifluoromethylphenyl group).

The alkyl part of the aralkyl group for R ¹⁵ may be either linear or branched. The carbon number of the aralkyl group is usually 7 to 20, preferably 7 to 10. The aralkyl is typically a phenylalkyl group such as a benzyl group or a phenylbutyl group (such as 3-amino-1-phenylbutyl group).

The acyl group for R ¹⁵ may be unsubstituted or may be bonded to a substituent such as a saturated aliphatic hydrocarbon group or an alkoxyl group. Carbon number of an acyl group is counted including carbon number of a substituent, and the number is 2-10 normally, Preferably it is 6-10. Examples of the acyl group include an acetyl group, a benzoyl group, and a methoxybenzoyl group (such as a p-methoxybenzoyl group).

R ¹³ and R ¹⁴ represent a hydrogen atom, a cyano group, a carbamoyl group, or an N-substituted carbamoyl group. The carbamoyl group has a structural formula of —CON (R ¹⁶ ) R ¹⁷ (wherein R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, a C _1-10 saturated aliphatic hydrocarbon group, C _1-8 A C _1-10 saturated aliphatic hydrocarbon group substituted by an alkoxyl group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms .). Descriptions and specific examples of the saturated aliphatic hydrocarbon group, aryl group, aralkyl group, and acyl group for R ¹⁶ and R ¹⁷ are the same as those described above for R ¹⁵ . However, specific examples of the acyl group further include a benzoyl group containing a halogen atom, such as a bromobenzoyl group (such as a p-bromobenzoyl group).

R ^{1 to} R ¹⁷ may be further limited from the viewpoint of enhancing color density, water solubility, oil solubility, light resistance, and the like. For example, to increase the color density, at least one (preferably all) of R ^{1 to} R ⁴ is a saturated aliphatic hydrocarbon group having 5 or less (preferably 3 or less) carbon atoms (for example, methyl group, ethyl group). Group) or a hydrogen atom is recommended.

In order to increase color density, at least one of R ¹⁶ and R ¹⁷ (preferably both) is a saturated aliphatic hydrocarbon group having 3 or less carbon atoms (for example, a methyl group, an ethyl group, etc., particularly a methyl group). It is recommended to select a hydrogen atom. In order to increase the solubility, it is preferable to select an acetyl group for at least one of R ¹⁶ and R ¹⁷ .

Further, from the viewpoint of enhancing the color density and water solubility, one or more of R ^{5 to} R ¹² (for example, one or more (especially one) from R ^{5 to} R ⁸ ), and R ^{9 to} R ¹² to 1 are used. It is recommended that one or more (especially one) be a sulfo group and the remaining R ^{5 to} R ¹² be a hydrogen atom or a sulfo group. By increasing the water solubility, it can be widely used as a pigment in the clothing field. As a coloring matter in the clothing field, one type of azo compound (I) may be used alone, or two or more types may be used in combination.

From the viewpoint of enhancing color density and oil solubility, one or more of R ^{5 to} R ¹² (for example, one or more (especially one) from R ^{5 to} R ⁸ ) and one from R ^{9 to} R ^12. For the above (especially one), it is recommended to employ a trifluoromethyl group or an N-substituted sulfamoyl group. In particular, the azo compound (I) in which one of R ^{5 to} R ¹² is an N-substituted sulfamoyl group exhibits high oil solubility even when the remaining one of R ^{5 to} R ¹² is a hydrophilic sulfo group. Show. By increasing the oil solubility, usefulness as a pigment in the field of liquid crystal display devices is increased. As a pigment in the field of liquid crystal display devices, one kind of azo compound (I) may be used alone, or two or more kinds may be used in combination.

When two or more azo compounds (I) are used in combination, the amount dissolved in an organic solvent (oil solubility) is greater than when one of them is used alone. Therefore, from the viewpoint of oil solubility, it is also a preferred embodiment to use a combination of two or more kinds of azo compounds (I) as the dye of the liquid crystal display device. As an example of a combination with improved oil solubility, an azo compound having two N-substituted sulfamoyl groups (disulfonamide) and an azo compound having one N-substituted sulfamoyl group and one sulfo group (monosulfonamide) Combinations are mentioned. Among such combinations, one of R ^{5 to} R ⁸ and one of R ^{9 to} R ¹² is an N-substituted sulfamoyl group, and the remainder is a hydrogen atom, and R ^{5 to} R A combination with a monosulfonamide in which one of ⁸ is an N-substituted sulfamoyl group, one of R ^{9 to} R ¹² is a sulfo group, and the remainder is a hydrogen atom is preferred. Monosulfonamide is preferable to disulfonamide from the viewpoint of color density. This is because the molecular weight is low.

From the viewpoint of enhancing oil solubility, one or more of R ^{5 to} R ¹² (for example, one or more (especially one) from R ^{5 to} R ⁸ and one or more from R ^{9 to} R ¹² (particularly, particularly) 1))) or a relatively bulky group from the above examples, or one or more of R ^{5 to} R ¹² (eg, one or more (especially one) from R ^{5 to} R ⁸ ), It is also recommended that one or more (especially one) of R ^{9 to} R ^{12 be} substituted at the meta position or the ortho position relative to the azo group. By selecting a bulky group or setting the substitution position to the meta position with respect to the azo group, stacking of the biphenyl moiety can be reduced and oil solubility can be increased. Moreover, the azo group can be protected and the light resistance can be improved by selecting a bulky group or by making the substitution position ortho to the azo group. Examples of the bulky R ^{5 to} R ¹² include two or more (particularly 3) such as a branched saturated aliphatic hydrocarbon group such as a tert-butyl group (particularly a tertiary saturated aliphatic hydrocarbon group) and a trifluoromethyl group. And a saturated aliphatic hydrocarbon group to which a halogen atom is bonded) or an N-substituted sulfamoyl group.

Furthermore, R ^{15 of the} N-substituted sulfamoyl group may be further limited from the viewpoint of further enhancing the color density, oil solubility, and the like. Examples of such R ¹⁵ include a methylbutyl group (such as 1,1,3,3-tetramethylbutyl group), a methylhexyl group (such as 1,5-dimethylhexyl group), and an ethylhexyl group (2 A branched saturated aliphatic hydrocarbon group such as a methylcyclohexyl group (such as a 2-methylcyclohexyl group), a phenylbutyl group (such as a 3-amino-1-phenylbutyl group), or an aralkyl group. It is done.

Particularly preferred azo compounds (I) are one or more of R ^{5 to} R ¹² , preferably 2 or more (for example, one to one or more (especially one) from R ^{5 to} R ⁸ ), and R ^{9 to} R ¹² to 1 One or more (especially one) is an N-substituted sulfamoyl group.

  Preferred examples of formula (I) include formulas (I-1) to (I-11).

Furthermore, preferred examples of formula (I) include, as represented by formula (II), at least one of R ^{5 to} R ⁸ and at least one of R ^{9 to} R ¹² are —SO ₂ NHR ¹⁵ groups. Also included are compounds in which the remainder is a hydrogen atom.

  Preferred examples of formula (II) are formulas (II-1) to (II-8).

The present invention includes not only the compound represented by formula (I) but also a salt thereof. Examples of the salt include a sulfonate when R ^{5 to} R ¹² are sulfo groups, and a carboxylate when R ^{5 to} R ¹² are carboxyl groups. The cations forming these salts are not particularly limited, but considering solubility in solvents, alkali metal salts such as lithium salts, sodium salts and potassium salts; ammonium salts; and ethanolamine salts and alkylamine salts. Organic amine salts and the like are preferred. In particular, an alkali metal salt (preferably a sodium salt) is useful when contained in a polarizing film substrate. In addition, the organic amine salt is useful when it is contained in a resin curable compound. Furthermore, since it is a non-metallic salt, it is also useful in fields where insulation is important.

The azo compound of the present invention can be produced by coupling a diazonium salt and a pyridone, as is well known in the dye field. For example, a compound of the formula (b) obtained by diazotizing a benzidine compound (diazo component) represented by the formula (a) with nitrous acid, nitrite or nitrite can be used as the diazonium salt (formula ( In a) and (b), R ^{5 to} R ¹² represent the same meaning as described above.

Then, the azo compound (I) is produced by reacting the diazonium salt (b) with the pyridone represented by the formula (c) (coupling component) usually at 20 to 60 ° C. in an aqueous solvent. (In formula (c), R ¹⁸ represents the same as R ¹ or R ³ , R ¹⁹ represents the same as R ² or R ^4, and R ²⁰ represents R ¹³ or R 3). ^The same as ¹⁴ ).

The target compound in which at least one of R ^{5 to} R ¹² in the formula (I) is a sulfamoyl group or an N-substituted sulfamoyl group can also be produced by using the compound (a) having a sulfamoyl group or an N-substituted sulfamoyl group. After the coupling reaction using the compound (a) having a sulfo group, it is sure to produce by sulfonamidation. For example, a compound in which at least one of R ^{5 to} R ¹² in formula (I) is a sulfo group (hereinafter referred to as “azosulfonic acid (I)”) is synthesized, and a sulfo group (—SO ₃ H) is obtained by using a thionyl halide compound. ) Can be converted to a sulfohalide (—SO ₂ X; X is a halogen atom) and then reacted with an amine to sulfonamidize the sulfo group.

  Preferred examples of the azosulfonic acid (I) include the formulas (I-1) to (I-7), (I-9) and (I-10), particularly the formulas (I-1) to (I— 3), (I-9) and (I-10). Examples of the thionyl halide compound include thionyl fluoride, thionyl chloride, thionyl bromide, thionyl iodide and the like, preferably thionyl chloride, thionyl bromide and the like, particularly thionyl chloride. The amount of thionyl halide used is, for example, about 1 to 10 moles with respect to 1 mole of azosulfonic acid (I). When water is brought into the reaction system, it is preferable to use an excessive amount of the thionyl halide compound.

  The sulfonation is usually performed in a solvent. Examples of the solvent include ethers such as 1,4-dioxane (particularly cyclic ethers); chloroform, methylene chloride, carbon tetrachloride, 1,2-dichloroethane, dichloroethylene, trichloroethylene, perchloroethylene, dichloropropane, amyl chloride. Halogenated hydrocarbons such as 1,2-dibromoethane can be used. The amount of the solvent used is, for example, about 3 parts by mass (preferably 5 parts by mass or more) and 10 parts by mass or less (preferably 8 parts by mass or less) with respect to 1 part by mass of the azo compound (I).

  In sulfonation, it is recommended to use N, N-dialkylformamide (for example, N, N-dimethylformamide, N, N-diethylformamide, etc.) in combination. When N, N-dialkylformamide is used, the amount used is, for example, about 0.05 to 1 mol with respect to 1 mol of the thionyl halide. Heat generation can be suppressed by adding thionyl halide after previously mixing azosulfonic acid (I) and N, N-dialkylformamide in a solvent.

  The reaction temperature is, for example, 0 ° C. or higher (preferably 30 ° C. or higher) and 70 ° C. or lower (preferably 60 ° C. or lower). The reaction time is, for example, about 0.5 hours or more (preferably 3 hours or more) and 8 hours or less (preferably 5 hours or less).

  The sulfone halide compound prepared as described above may be isolated and then reacted with the amine, or may be reacted with the amine in the form of a reaction mixture without isolation. In the case of isolation, for example, the reaction mixture and water may be mixed, and the precipitated crystals may be collected by filtration. The obtained sulfone halide compound crystals may be washed with water and dried as necessary before the reaction with the amine.

Examples of the amine include a primary amine, and the primary amine is represented by the formula H ₂ N—R ¹⁵ (R ¹⁵ is the same as described above). Specific examples of H ₂ N—R ¹⁵ include n-propylamine, n-butylamine, n-hexylamine, dimethylhexylamine (such as 1,5-dimethylhexylamine), tetramethylbutylamine (1,1,3,3). 3-tetramethylbutylamine and the like), ethylhexylamine (such as 2-ethylhexylamine), aminophenylbutane (such as 3-amino-1-phenylbutane), and isopropoxypropylamine. The amount of amine used is usually about 3 mol or more and 10 mol or less (preferably 7 mol or less) with respect to 1 mol of the sulfone halide compound. In this specification, in order to distinguish this amine from the basic catalyst described later, hereinafter, it may be referred to as a reactive amine.

  The order of addition of the sulfone halide compound and the amine is not particularly limited, but an amine is often added (dropped) to the sulfone halide compound. The reaction between the sulfone halide compound and the amine is usually performed in a solvent. As the solvent, the same solvent as that used for preparing the sulfone halide compound can be used.

  The reaction between the sulfone halide and the reactive amine is preferably carried out in the presence of a basic catalyst. Examples of the basic catalyst include tertiary amines (particularly aliphatic tertiary amines such as triethylamine and triethanolamine), pyridine bases such as pyridine and methylpyridine, and the like. Among these, tertiary amines, particularly aliphatic tertiary amines such as triethylamine are preferable. The usage-amount of a basic catalyst is about 1.1 mol or more and 6 mol or less (preferably 5 mol or less) normally with respect to a reactive amine (the said amine reacted with a sulfone halide).

  When a reactive amine and a basic catalyst are added to the sulfone halide compound, the timing of adding the basic catalyst is not particularly limited, and may be either before or after the addition of the reactive amine, and is the same as the reactive amine. It may be added at the timing. Further, it may be added after mixing with the reactive amine in advance, or may be added separately from the reactive amine.

  The reaction temperature of the sulfone halide and the reactive amine is, for example, 0 ° C. or higher and 50 ° C. or lower (preferably 30 ° C. or lower). The reaction time is usually about 1 to 5 hours.

  The method for obtaining the target sulfonamide compound from the reaction mixture is not particularly limited, and various known methods can be employed. For example, the reaction mixture is mixed with an acid (acetic acid) and water, and the precipitated crystals are filtered. You may take it. The acid and water are often used after an aqueous acid solution is prepared in advance, and the reaction mixture is often added to the aqueous acid solution. The addition temperature of the reaction mixture is usually 10 ° C. or higher (preferably 20 ° C. or higher) and 50 ° C. or lower (preferably 30 ° C. or lower). Moreover, after addition, it is common to stir at the same temperature for about 0.5 to 2 hours. The crystal collected by filtration is usually washed with water and then dried. Moreover, you may refine | purify further by well-known methods, such as recrystallization, as needed.

  EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and appropriate modifications are made within a range that can meet the above and the following purposes. Of course, it is possible to implement them, and they are all included in the technical scope of the present invention. In the examples and comparative examples, “%” and “parts” are mass% and mass parts unless otherwise specified.

Example 1
100 parts of water was added to 10 parts of 2,2′-benzidinedisulfonic acid (containing 30% water) represented by the formula (a-1), and then adjusted to pH 7-8 with 30% aqueous sodium hydroxide solution under ice cooling. did. The following operations were performed under ice cooling. 5.6 parts of sodium nitrite was added and stirred for 30 minutes. After adding 14.8 parts of 35% hydrochloric acid little by little to give a brown solution, the mixture was stirred for 2 hours. An aqueous solution in which 3.8 parts of amidosulfuric acid was dissolved in 38.3 parts of water was added to the reaction solution and stirred to obtain a suspension containing a diazonium salt.

  After adding 47.9 parts of water to 9.6 parts of 1-ethyl-3-carbamoyl-4-methyl-6-hydroxypyrid-2-one represented by the formula (c-1), The pH was adjusted to 8-9 with a 30% aqueous sodium hydroxide solution.

  The following operations were performed under ice cooling. The aqueous alkaline solution of pyridones was stirred to give a colorless solution, and then a suspension containing a diazonium salt was added dropwise with a pump while adjusting the pH to 8 to 9 with a 30% aqueous sodium hydroxide solution. After completion of dropping, the mixture was further stirred for 3 hours to obtain a yellow suspension. The yellow solid obtained by filtration was dried at 60 ° C. under reduced pressure to obtain 15.7 parts of an azo compound represented by the formula (I-1).

The structure of the azo compound (I-1) was determined by ¹ H-NMR and ¹³ C-NMR analysis. As an analytical instrument, ECA-500 (manufactured by JEOL Ltd.) was used.
¹ H-NMR (500 MHz, δ value (ppm, TMS standard), DMSO); 1.15 (6H, t, J = 6.9 Hz), 2.25 (6H, s), 3.91 (4H, q, J = 6.9 Hz), 7.37 (2H, d, J = 8.5 Hz), 7.46 (2H, dd, J = 8.5, 2.3 Hz), 7.51 (2H, br .D, J = 1.9 Hz), 7.71 (2H, br.d, J = 1.9 Hz), 8.03 (2H, d, J = 2.3 Hz), 14.44 (2H, s)
¹³ C-NMR (125 MHz, δ value (ppm, TMS standard), DMSO); 12.9, 14.1, 33.8, 114.9, 115.1, 123.1, 125.4, 133.9 135.0, 139.6, 143.8, 146.2, 160.6, 160.7, 166.4

0.35 g of the obtained azo compound (I-1) was dissolved in N, N-dimethylformamide to a volume of 250 cm ³ , 2 cm ^{3 of} which was diluted with water to a volume of 100 cm ³ (concentration: 0.00). 028 g / L) and a spectrophotometer (quartz cell, cell length is 1 cm), the absorption spectrum was measured. The obtained absorption spectrum is shown in FIG. This compound showed an absorbance of 2.86 (arbitrary unit) at λmax = 450 nm.

Example 2
After adding 156 parts of ethanol and 52 parts of water to 10.4 parts of 2,2′-bis (trifluoromethyl) benzidine represented by the formula (a-2), the mixture was washed with a 30% aqueous sodium hydroxide solution under ice cooling. The pH was adjusted to 7-8. The following operations were performed under ice cooling. 6.7 parts of sodium nitrite was added and stirred for 30 minutes. After adding 30.4 parts of 35% hydrochloric acid little by little to give a brown suspension, the mixture was stirred for 2 hours. An aqueous solution obtained by dissolving 3.1 parts of amidosulfuric acid in 31 parts of water was added to the reaction solution and stirred to obtain a suspension containing a diazonium salt.

  After adding 15 parts of ethanol and 221 parts of water to 14.7 parts of 1-ethyl-3-carbamoyl-4-methyl-6-hydroxypyrid-2-one represented by the formula (c-1), The pH was adjusted to 8-9 with a 30% aqueous sodium hydroxide solution.

  The following operations were performed under ice cooling. After stirring the alkaline aqueous solution of pyridones to make a brown solution, a suspension containing a diazonium salt was dropped by a pump while adjusting the pH to 8 to 9 with a 30% aqueous sodium hydroxide solution. After completion of dropping, the mixture was further stirred for 3 hours to obtain a yellow suspension. The yellow solid obtained by filtration was dried at 60 ° C. under reduced pressure to obtain 19.2 parts of an azo compound represented by the formula (I-8).

0.35 g of the obtained azo compound (I-8) was dissolved in ethyl lactate to a volume of 250 cm ³ , 2 cm ^{3 of} which was diluted with ethyl lactate to a volume of 100 cm ³ (concentration: 0.028 g / L). ), And the absorption spectrum was measured using a spectrophotometer [quartz cell, cell length is 1 cm]. The obtained absorption spectrum is shown in FIG. This compound showed an absorbance of 2.42 (arbitrary unit) at λmax = 430 nm.

Example 3
After adding 1000 parts of water to 100 parts of 2,2′-benzidinedisulfonic acid (containing 30% water) represented by the formula (a-1), the pH is adjusted to 7-8 with 30% aqueous sodium hydroxide solution under ice cooling. did. The following operations were performed under ice cooling. 56.1 parts of sodium nitrite was added and stirred for 30 minutes. After adding 148 parts of 35% hydrochloric acid little by little to give a brown solution, the mixture was stirred for 2 hours. An aqueous solution in which 38.3 parts of amidosulfuric acid was dissolved in 383 parts of water was added to the reaction solution and stirred to obtain a suspension containing a diazonium salt.

  761 parts of water was added to 76.1 parts of 1-ethyl-3-cyano-4-methyl-6-hydroxypyrid-2-one represented by the formula (c-2), and then 30% under ice cooling. The pH was adjusted to 8-9 with an aqueous sodium hydroxide solution.

  The following operations were performed under ice cooling. The aqueous alkaline solution of pyridones was stirred to give a colorless solution, and then a suspension containing a diazonium salt was added dropwise with a pump while adjusting the pH to 8 to 9 with a 30% aqueous sodium hydroxide solution. After completion of dropping, the mixture was further stirred for 3 hours to obtain a yellow suspension. The yellow solid obtained by filtration was dried at 60 ° C. under reduced pressure to obtain 157 parts of an azo compound represented by the formula (I-9).

The structure of the azo compound (I-9) was determined by ¹ H-NMR and ¹³ C-NMR analysis. As an analytical instrument, ECA-500 (manufactured by JEOL Ltd.) was used.
¹ H-NMR (500 MHz, δ value (ppm, TMS standard), DMSO); 1.14 (6H, t, J = 7.1 Hz), 2.53 (6H, s), 3.89 (4H, br .Q, J = 7.1 Hz), 7.37 (2H, d, J = 8.5 Hz), 7.59 (2H, dd, J = 8.5, 2.3 Hz), 8.15 (2H, br.d, J = 2.3 Hz), 14.73 (2H, br.s)
¹³ C-NMR (125 MHz, δ value (ppm, TMS standard), DMSO); 12.8, 16.4, 34.5, 100.0, 115.3, 116.3, 116.5, 123.1 133.9, 136.5, 139.3, 146.1, 158.9, 159.9, 160.2

  0.35 g of the obtained azo compound (I-9) was measured under the same conditions as in Example 1. The obtained absorption spectrum is shown in FIG. This compound showed an absorbance of 3.31 (arbitrary unit) at λmax = 463 nm.

Example 4
A flask equipped with a condenser and a stirrer was charged with 5 parts of azo compound (I-1), 50 parts of chloroform and 2.1 parts of N, N-dimethylformamide, and while stirring, maintaining the temperature at 20 ° C. or lower, 6 parts of thionyl chloride was added dropwise. After completion of the dropwise addition, the temperature was raised to 50 ° C., maintained at the same temperature for 5 hours for reaction, and then cooled to 20 ° C. While maintaining the reaction solution after cooling at 20 ° C. or lower with stirring, a mixed solution of 4 parts of 1,5-dimethylhexylamine and 14 parts of triethylamine was added dropwise. Thereafter, the reaction was carried out by stirring overnight at the same temperature. Next, after the solvent of the obtained reaction mixture was distilled off with a rotary evaporator, a small amount of methanol was added and stirred vigorously. This mixture was added to a mixed solution of 29 parts of acetic acid and 300 parts of ion-exchanged water with stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed well with ion exchange water, and dried under reduced pressure at 60 ° C. to obtain 3.6 parts (yield 56%) of the azo compound represented by the formula (II-1).

  The absorption spectrum of the azo compound (II-1) was measured under the same conditions as in Example 2. The obtained absorption spectrum is shown in FIG. This compound showed an absorbance of 2.64 (arbitrary unit) at λmax = 451 nm.

Example 5
A flask equipped with a condenser and a stirrer was charged with 5 parts of an azo compound (I-9), 50 parts of chloroform and 2.1 parts of N, N-dimethylformamide, and while maintaining the temperature at 20 ° C. or lower with stirring, 3 parts of thionyl chloride was added dropwise. After completion of the dropwise addition, the temperature was raised to 50 ° C., maintained at the same temperature for 5 hours for reaction, and then cooled to 20 ° C. While maintaining the reaction solution after cooling at 20 ° C. or lower with stirring, a mixed solution of 4 parts of 1,5-dimethylhexylamine and 14 parts of triethylamine was added dropwise. Thereafter, the reaction was carried out by stirring overnight at the same temperature. Next, after the solvent of the obtained reaction mixture was distilled off with a rotary evaporator, a small amount of methanol was added and stirred vigorously. This mixture was added to a mixed solution of 29 parts of acetic acid and 300 parts of ion-exchanged water with stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed well with ion exchange water, and dried under reduced pressure at 60 ° C. to obtain 5.6 parts of an azo compound.

  The obtained azo compound was subjected to structural analysis by LC-MS analysis. The analytical instrument is Agilent 1100 (manufactured by Agilent Technology), the column is Sumipax ODS (manufactured by Sumika Chemical Analysis Co., Ltd.), and the elution solvent is 0.1% trifluoromethylacetic acid in a water-acetonitrile mixed solvent. % Solvent system was used. As a result, in the obtained azo compound, the azo compound represented by the formula (II-6) (disulfonamide, accurate mass 944) was present in the total solid content at 58.3% by mass, and the formula (I-11) In which the azo compound (monosulfonamide, accurate mass 833) represented by the formula (1) was present in 30.1% by mass in the total solid content.

  The absorption spectrum of the azo compound (II-6) was measured under the same conditions as in Example 2. The obtained absorption spectrum is shown in FIG. This compound showed an absorbance of 3.47 (arbitrary unit) at λmax = 452 nm.

Comparative Example 1
The absorption spectrum of the azo compound represented by the formula (III-1) (manufactured by BASF: “Neptun Yellow 075”) was measured under the same conditions as in Example 2. The obtained absorption spectrum is shown in FIG. This compound showed an absorbance of 2.46 (arbitrary unit) at λmax = 428 nm.

  The azo compounds (II-1) and (II-6) of Examples 4 and 5 and the azo compound (III-1) of Comparative Example 1 are the number of azo groups, phenyl groups, and pyridone rings per gram ( The number of moles) is almost the same. However, the absorbance (concentration: 0.028 g / L) of the azo compound (II-1) is 0.18 greater than the absorbance of the azo compound (III-1) at the same concentration. Further, in the azo compound (II-6), the absorbance at the same concentration is 1.01 larger than that of the azo compound (III-1). These results indicate that the azo compound of the present invention having a pyridone ring at both ends of the biphenyl skeleton or a salt thereof has a high color density.

Example 6
The oil solubility (solubility in propylene glycol monomethyl ether) between the azo compound (I-1) having a sulfo group and the azo compound (II-1) having an N-substituted sulfamoyl group was determined as follows:

1 g of azo compound and 9 g of propylene glycol monomethyl ether were placed in a vial and stirred for a whole day and night, and then the solid matter remaining undissolved was removed by filtration (if the azo compound was completely dissolved, the filtrate concentration was 10% by mass). . The absorption spectrum of the filtrate thus obtained was measured in the same manner as in Example 1 except that 3.5 g of the filtrate was used, and the absorbance (Int (a)) at λmax of each azo compound was determined. . Further, using 0.35 g of each azo compound, the absorbance (Int (r)) at λmax of each azo compound was determined in the same manner as in Example 1. And the following formula:
Solubility (mass%) = (Int (a) × 10) / Int (r)
From this, the solubility of each azo compound was calculated. The results are shown in Table 1.

  From the results in Table 1, it can be seen that the oil solubility of the azo compound of the present invention is improved by introducing an N-substituted sulfamoyl group.

  The azo compound or salt thereof of the present invention exhibits a very high color density. Therefore, even with a small amount of use, a dyed product having the same quality as the conventional one can be obtained from the azo compound of the present invention or a salt thereof, which is advantageous in terms of cost. In addition, when the azo compound of the present invention or a salt thereof is used in a curable resin composition for producing a liquid crystal display component, the amount used is reduced, and thus a component excellent in performance such as solvent resistance and heat resistance is produced. it can. Furthermore, the azo compound of the present invention or a salt thereof may be used alone as an excellent dye, or may be used in combination with other dyes as a toning dye. As described above, the azo compound of the present invention having a high color density or a salt thereof can be used for various purposes other than producing dyed products and liquid crystal display parts.

It is a figure which shows the absorption spectrum of the azo compound (Example 1) represented by a formula (I-1). It is a figure which shows the absorption spectrum of the azo compound (Example 2) represented by Formula (I-8). It is a figure which shows the absorption spectrum of the azo compound (Example 3) represented by Formula (I-9). It is a figure which shows the absorption spectrum of the azo compound (Example 4) represented by Formula (II-1). It is a figure which shows the absorption spectrum of the azo compound (Example 5) represented by Formula (II-6). It is a figure which shows the absorption spectrum of the azo compound (Comparative Example 1) represented by Formula (III-1).

Claims (7)

An azo compound represented by the formula (I) or a salt thereof.

[In formula (I), R ^{1 to} R ⁴ each independently represents a hydrogen atom, a C _1-10 saturated aliphatic hydrocarbon group or a carboxyl group.
R ^{5 to} R ¹² are each independently a hydrogen atom, halogen atom, C _1-10 saturated aliphatic hydrocarbon group, halogenated C _1-10 saturated aliphatic hydrocarbon group, C _1-8 alkoxyl group, carboxyl Represents a group, a sulfo group, a sulfamoyl group, or an N-substituted sulfamoyl group.
R ¹³ and R ¹⁴ each independently represents a hydrogen atom, a cyano group, a carbamoyl group, or an N-substituted carbamoyl group. ] At least one of R ⁵ to R ¹² is an azo compound or a salt thereof according to claim 1 which is N- substituted sulfamoyl group. The azo compound or a salt thereof according to claim 2, wherein at least one of R ^{5 to} R ⁸ and at least one of R ^{9 to} R ¹² is an N-substituted sulfamoyl group. The azo compound or a salt thereof according to claim 3, wherein at least one of R ⁵ and R ⁸ and at least one of R ⁹ and R ¹² is an N-substituted sulfamoyl group. The N-substituted sulfamoyl group is a —SO ₂ NHR ¹⁵ group, and R ¹⁵ is a C _1-10 saturated aliphatic group substituted with a C _1-10 saturated aliphatic hydrocarbon group or a C _1-8 alkoxyl group. The azo compound according to any one of claims 1 to 4, which represents a hydrocarbon group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms. Its salt. The azo compound or a salt thereof according to any one of claims 1 to 5, wherein at least one of R ¹³ and R ¹⁴ is a cyano group. At least one of R ¹³ and R ¹⁴ is a —CON (R ¹⁶ ) R ¹⁷ group, and each of R ¹⁶ and R ¹⁷ independently represents a hydrogen atom, a C _1-10 saturated aliphatic hydrocarbon group, C _{1 -8} alkoxyl group substituted C _1-10 saturated aliphatic hydrocarbon group, an aryl group having 6 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, or an acyl group having 2 to 10 carbon atoms The azo compound according to any one of claims 1 to 5 or a salt thereof.

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