JPH06240163A - Production of trimethine pigment - Google Patents

Abstract

PURPOSE:To efficiently produce a trimethine pigment useful as an intermediate, etc., of an electron-donative colorless dye for a recording material from low-cost raw materials in a high yield by reacting a specified aniline compound with a tetraalkoxypropane in the presence of a Lewis acid, etc. CONSTITUTION:The pigment of formula II (X<-> is a counter ion) is produced by reacting an aniline compound of formula I (R1 and R2 are each an alkyl or an aryl; R3 to R6 are each H, an alkyl, alkoxy, aryl, aryloxy, alkylthio, arylthio, a (substituted)amino or a halogen) with a 1,1,3,3-tetraalkoxypropane in the presence of a Lewis acid such as titanium chloride and a base such as triethylamine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trimethine color former useful as a recording material using an electron-donating colorless dye and an electron-accepting compound, for example, an electron-donating colorless dye for pressure-sensitive recording materials, heat-sensitive recording materials and the like. To a method for producing a trimethine dye which is an intermediate of

[0002]

2. Description of the Related Art There are several known methods for producing trimethine dyes, but all have drawbacks such as a large number of steps and unstable raw materials. For example, a method of producing a trimethine dye by dehydrating and condensing p-substituted aminobenzaldehyde and p-substituted aminoacetophenone to form a chalcone derivative, then reducing the ketone portion, and dehydrating the formed carbinol portion with an acid, takes 3 steps. Further, in the method for producing a trimethine dye by the reaction of p-substituted aminocinnamaldehyde and p-substituted aminophenyllithium,
The lithium compound as a raw material is unstable, and there is a problem in industrial use.

[0003]

SUMMARY OF THE INVENTION The present invention is to provide a trimethine dye which is an intermediate of a trimethine color former which is useful as an electron-donating colorless dye for recording materials.

[0004]

The above object is to react an aniline compound represented by the following general formula (I) with 1,1,3,3-tetraalkoxypropane in the presence of a Lewis acid and a base. This has been achieved by a method for producing a trimethine dye represented by the following general formula (II). General formula (I)

[0005]

[Chemical 6]

In the formula, R ₁ and R ₂ are alkyl groups and aryl groups, and R _{3 to} R ₆ are hydrogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, alkylthio groups,
It represents an arylthio group, a substituted amino group or a halogen atom.
General formula (II)

[0007]

[Chemical 7]

In the formula, X ^- represents a counter anion. The alkyl group and the aryl group further include an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a halogen atom, a nitro group, a cyano group, a substituted carbamoyl group, a substituted sulfamoyl group, a substituted amino group, a substituted oxycarbonyl group and a substituted oxy group. It may have a substituent such as a sulfonyl group, an alkylthio group and an arylsulfonyl group.

Specifically, R ₁ and R ₂ have 1 to 1 carbon atoms.
An alkyl group having 8 carbon atoms and an aryl group having 6 to 12 carbon atoms are preferable, and R ₁ and R ₂ are bonded to each other to contain a 5-membered to 8-membered hetero atom including the nitrogen atom bonded to them. A ring which may be, for example, pyrrolidine, piperidine, morpholine, thiomorpholine, piperazine, caprolactam ring may be formed, and further R ₁ and R ₃ , R
₂ and R ₅ may combine with each other to form an indoline or julolidine ring.

As NR ₁ R ₂ , dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, dipentylamino group, dihexylamino group, dioctylamino group, diphenylamino group, ditolylamino group, dibenzylamino group, N -Methyl-N-ethylamino group, N-methyl-N-butylamino group, N-ethyl-
N-butylamino group, N-ethyl-N-β-methoxyethylamino group, N-ethyl-N-β-ethoxyethylamino group, N-ethyl-N-β-phenoxyethylamino group, N-methyl-N -Β-cyanoethylamino group, N-
Methyl-N-β-chloroethylamino group, N-ethyl-
N-cyclohexylamino group, N-ethyl-N-pentylamino group, N-ethyl-N-tetrahydrofurfurylamino group, N-ethyl-N-tolylamino group, N-ethyl-N-methoxyphenylamino group, N- Ethyl-N-
Benzylamino group, N-ethyl-N-chlorobenzylamino group, pyrrolidino group, piperidino group, morpholino group,
An example is a piperazino group.

Among the substituents represented by R _{3 to} R ₆ , a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group, an alkylthio group, an acyloxy group, an aryl group having 6 to 12 carbon atoms, and aryloxy. A group, an arylthio group, a chlorine atom, a bromine atom, a fluorine atom, a mono- or dialkylamino group having 1 to 12 carbon atoms, a mono- or diarylamino group having 6 to 12 carbon atoms, and an acylamino group having 1 to 12 carbon atoms. preferable.

R _{3 to} R ₆ are hydrogen atom, methyl group,
Ethyl group, propyl group, butyl group, octyl group, phenyl group, tolyl group, benzyl group, phenethyl group, methoxy group, ethoxy group, propoxy group, butoxy group, octyloxy group, benzyloxy group, phenoxyethoxy group,
Phenoxy group, methylthio group, chlorine atom, bromine atom, fluorine atom, dimethylamino group, diethylamino group, dipropylamino group, dibutylamino group, dipentylamino group, dihexylamino group, dioctylamino group, diphenylamino group, ditolylamino group, Dibenzylamino group, N-methyl-N-ethylamino group, N-methyl-N
-Butylamino group, N-ethyl-N-butylamino group,
N-ethyl-N-β-methoxyethylamino group, N-ethyl-N-β-ethoxyethylamino group, N-ethyl-
N-β-phenoxyethylamino group, N-methyl-N-
β-cyanoethylamino group, N-methyl-N-β-chloroethylamino group, N-ethyl-N-cyclohexylamino group, N-ethyl-N-pentylamino group, N-ethyl-N-tetrahydrofurfurylamino group , N-ethyl-N-tolylamino group, N-ethyl-N-methoxyphenylamino group, N-ethyl-N-benzylamino group, N
Examples include -ethyl-N-chlorobenzylamino group, pyrrolidino group, piperidino group, morpholino group, piperazino group, and acetylamino group.

The amount of the aniline compound used in the present invention is 1,
0.5 for 1,3,3-tetraalkoxypropane
It is preferable to use 5 to 5 equivalents, particularly preferably 2 to 3 equivalents. X ⁻ represents a counter anion and represents an acid residue.
Examples of the alkoxy group of 1,1,3,3-tetraalkoxypropane used in the present invention include a methoxy group, an ethoxy group and a propoxy group.

The base means a base defined by Lewis. In this production method, a Lewis base containing an N atom having an unshared electron pair can be preferably used. More preferably, at least one of the compound represented by the general formula (III), the compound represented by the general formula (IV) and the compound represented by the general formula (V) can be used. General formula (III)

[0015]

[Chemical 8]

In the formula, R _{7 to} R ₉ represent a hydrogen atom, an alkyl group, a cycloalkyl group or a phenyl group having a substituent at the p-position. However, at least one of R _{7 to} R ₉ represents a group other than a hydrogen atom. R ₇ and R ₈ may combine with each other to form a 5- to 7-membered ring which may have a substituent. Specifically, R _{7 to} R ₉ are a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, and a phenyl group having a substituent at the p-position having 7 to 20 carbon atoms. Further, R ₇ and R ₈ may combine with each other to form a substituted or unsubstituted 5 to 7 membered ring containing the nitrogen atom to which they are bonded. R _{7 to} R ₉ are hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, butyl group, octyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, p-methoxyphenyl group, p-tolyl group, p-
It is preferable that an ethylphenyl group, or R ₇ and R ₈ are bonded to each other to form a pyrrolidine ring or a piperidine ring. More specifically, triethylamine, tripropylamine, triisopropylamine, tributylamine, trioctylamine, diethylamine, diisopropylamine, dibutylamine, dioctylamine, dicyclohexylamine, diisopropylethylamine, N-isopropyl-
N-cyclohexylamine, pyrrolidine, piperidine,
N-methylpyrrolidine, N-methylpiperidine, 2,6
-Dimethylpyrrolidine, 2,2,6,6-tetramethylpyrrolidine, 2,6-dimethylpiperidine, 2,2
6,6-Tetramethylpiperidine, N, N-dimethyl-
p-toluidine, N, N-dimethyl-p-anisidine,
N, N-diethyl-p-toluidine, N, N-diethyl-p-anisidine and the like are preferable, and more preferably 2,
2,6,6-Tetramethylpiperidine, diisopropylamine, diisopropylethylamine, N, N-dimethyl-p-toluidine, N, N-dimethyl-p-anisidine, N, N-diethyl-p-toluidine, N, N- Diethyl-p-anisidine can be used. General formula (IV)

[0017]

[Chemical 9]

In the formula, R _{10 to} R ₁₄ are hydrogen atom, alkyl group, alkoxy group, aryl group, aryloxy group, alkylthio group, arylthio group, substituted amino group, hydroxy group, halogen atom, alkoxycarbonyl group, aryloxy. Carbonyl group, acyloxy group, cyano group,
Represents a nitro group. Among the substituents represented by R _{10 to} R ₁₄ ,
Hydrogen atom, alkyl group having 1 to 12 carbon atoms, alkoxy group, alkylthio group, alkoxycarbonyl group having 2 to 12 carbon atoms, acyloxy group, aryl group having 6 to 12 carbon atoms, aryloxy group, arylthio group, Aryloxycarbonyl group having 7 to 12 carbon atoms, hydroxy group, chlorine atom, bromine atom, fluorine atom, nitro group, cyano group, mono- or dialkylamino group having 1 to 12 carbon atoms, and 6 to 12 carbon atoms A mono- or diarylamino group and an acylamino group having 1 to 12 carbon atoms are preferable.

R _{10 to} R ₁₄ are hydrogen atoms, methyl groups,
Ethyl group, propyl group, butyl group, octyl group, phenyl group, tolyl group, benzyl group, phenethyl group, methoxy group, ethoxy group, propoxy group, butoxy group, octyloxy group, benzyloxy group, phenoxyethoxy group,
Phenoxy group, methylthio group, chlorine atom, bromine atom, fluorine atom, nitro group, cyano group, dimethylamino group, diethylamino group, pyrrolidino group, piperidino group, morpholino group, piperazino group, acetylamino group, acetyloxy group, methoxycarbonyl The group is raised. More specifically, pyridine, 2-picoline, 3-picoline, 4-picoline, 2,3-lutidine, 2,4-lutidine, 2,5-
Lutidine, 2,6-lutidine, 2,4,6-collidine,
2,6-diethylpyridine, 2,6-diisopropylpyridine, 2,6-diphenylpyridine, 2,6-ditolylpyridine, 2,6-bis (methoxyphenyl) pyridine, 2-cyanopyridine, 3-cyanopyridine, 4-cyanopyridine, methyl 2-nicotinate, methyl 3-nicotinate, methyl 4-nicotinate, 2-chloropyridine,
3-chloropyridine, 4-chloropyridine, 2-methoxypyridine, 3-methoxypyridine, 4-methoxypyridine, 2-fluoropyridine, 3-fluoropyridine,
4-fluoropyridine, 4-dimethylaminopyridine,
4-diethylaminopyridine, 4-piperidinopyridine and the like are preferable. General formula (V)

[0020]

[Chemical 10]

Where R₁₅~ R₁₇Is a hydrogen atom, alkyl
Represents a group, a cycloalkyl group, and an aryl group. However, R₁₅When
R₁₇Or R₁₆And R₁₇May be bonded to each other to have a substituent 5
A ~ 7-membered ring may be formed. In detail R₁₅~ R₁₇Is hydrogen
Atom, methyl group, ethyl group, propyl group, isopropyl
Group, butyl group, octyl group, cyclopropyl group, cyclo
Pentyl group, cyclohexyl group, phenyl group, tolyl
Group, methoxyphenyl group, benzyl group, or R₁₅And R
₁₇Combine to form a pyrrolidone ring and a piperidone ring,
Or R₁₆And R ₁₇Are joined to form a pyrrolidine ring, piperidine
It is preferable to form a ring or a morpholine ring. More concrete
Specifically, N, N-dimethylformamide, N, N-dimethyl
Luacetamide, N, N-diethylformamide, N,
N-diethylacetamide, N, N-dimethylpropio
Namide, N, N-dimethylbenzamide, N, N-di
Methyltoluamide, N-methyl-2-pyrrolidone, N-
Methyl-2-piperidone, N-acetylpiperidine, N
-Acetylpyrrolidine, N-acetylmorpholine, etc. are preferred.
Good The amount of base used is 1,1,3,3-tetra above.
1 to 100 equivalents based on alkoxypropane
It is preferable to use 2 to 10 equivalents.

The Lewis acid used in the present invention includes titanium (IV) chloride, aluminum chloride and tin chloride (I).
V) Compounds such as boron trifluoride diethyl ether complex, zirconium (IV) chloride, boron trichloride and trimethylsilyltrifluoromethanesulfonate can be used. It is particularly preferable to use titanium (IV) chloride or aluminum chloride. The amount of Lewis acid used is 1,
0.1 for 1,3,3-tetraalkoxypropane
It is preferable to use ˜100 equivalents, and particularly preferable to use 2 to 10 equivalents.

In the production method of the present invention, an organic solvent such as dichloromethane, 1,2-dichloroethane, benzene, toluene, xylene, chlorobenzene or dichlorobenzene may be used as an auxiliary solvent, and nitrogen gas, argon gas or the like may not be used. The reaction may be performed in an active gas atmosphere. The reaction temperature is preferably 0 to 130 ° C, particularly 10 to 5
0 ° C is preferred.

The raw materials may be added by simultaneously adding a Lewis acid and a base to a mixed solution of an organic solvent and / or an aniline compound and 1,1,3,3-tetraalkoxypropane, and adding an aniline compound to a Lewis acid. , 1, 3,
Method of adding a mixed solution of 3-tetraalkoxypropane and a base, 1,1, to a mixed solution of a Lewis acid and a base
Examples thereof include a method of adding a mixed solution of 3,3-tetraalkoxypropane and an aniline compound.

Specific examples of the trimethine dye of the present invention are shown below, but the present invention is not limited to these.

[0026]

[Chemical 11]

[0027]

[Chemical 12]

[0028]

[Chemical 13]

[0029]

[Chemical 14]

[0030]

EXAMPLES Examples will be shown below, but the present invention is not limited thereto. Unless otherwise specified,% means% by weight.

Example 1 Synthesis of Compound of Specific Example (1) In a three-necked flask equipped with a stirrer, 0.4 mol of N, N-dimethylaniline and 0.2 mol of 1,1,3,3-tetramethoxypropane. , 2,2,6,6-tetramethylpiperidine 0.4 mol, dichloromethane 150 m
l is weighed and 0.4 mol of titanium (IV) chloride is added dropwise with stirring at 15 ° C. After the dropping, stir for 30 minutes. The reaction mixture was poured into ice-water sodium hydroxide and extracted with ethyl acetate. The extract was concentrated and the residue was dissolved in 50 ml of tetrahydrofuran. 4 in this solution
0.1 mol of 2% borohydrofluoric acid and 200 ml of water were added, and the precipitated crystals were filtered, washed with water, and washed with chloroform to obtain 36.6 g of the desired product (yield 50%). Melting point 17
8-80 ° C. Absorption maximum (acetonitrile): 693n
m.

Example 2 34.4 g of the desired product (yield 47%) was obtained in the same manner as in Example 1 except that 2,2,6,6-tetramethylpiperidine of Example 1 was changed to 2,6-lutidine. Got

Example 3 The same procedure as in Example 1 was repeated except that 2,2,6,6-tetramethylpiperidine of Example 1 was changed to N, N-dimethyl-p-toluidine (34.4 g of the desired product). Rate of 47%).

Example 4 22.0 g (yield 30%) of the desired product was obtained in the same manner as in Example 1, except that the titanium (IV) chloride in Example 1 was changed to aluminum chloride.

Example 5 Synthesis Example of Compound of Concrete Example (13) The same procedure as in Example 1 except that N, N-dimethylaniline of Example 1 was replaced with N, N-dimethyl-m-toluidine. 39.4 g (yield 50%) was obtained. Absorption maximum (acetonitrile): 699 nm.

Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that 2,2,6,6-tetramethylpiperidine of Example 1 was omitted, and the target product was 7.3 g (yield 10%). Got

[0037]

Industrial Applicability According to the present invention, a trimethine dye useful as an intermediate for an electron-donating colorless dye can be industrially produced with a small number of steps and using stable and inexpensive raw materials.

Claims (2)

[Claims] 1. An aniline compound represented by the following general formula (I) and 1,1,3,3-tetraalkoxypropane are reacted in the presence of a Lewis acid and a base. ) A method for producing a trimethine dye represented by the general formula (I): In the formula, R ₁ and R ₂ are an alkyl group or an aryl group,
_{3 to} R ₆ represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group, an arylthio group, a substituted amino group, or a halogen atom. General formula (II): In the formula, X ⁻ represents a counter anion. 2. Trimethine according to claim 1, wherein at least one of the compounds represented by the following general formula (III), the following general formula (IV) or the following general formula (V) is used as a base. Method for producing dye General formula (III) In the formula, R _{7 to} R ₉ represent a hydrogen atom, an alkyl group, a cycloalkyl group, or a phenyl group having a substituent at the p-position. However, at least one of R _{7 to} R ₉ represents a group other than a hydrogen atom. R ₇ and R ₈ may combine with each other to form a 5- to 7-membered ring which may have a substituent. General formula (IV): In the formula, R _{10 to} R ₁₄ are a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group,
It represents an arylthio group, a substituted amino group, a hydroxy group, a halogen atom, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a cyano group, or a nitro group. General formula (V) In the formula, R _{15 to} R ₁₇ represent a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group. However, R ₁₅ and R ₁₇ or R
₁₆ and R ₁₇ may combine with each other to form a 5- to 7-membered ring which may have a substituent.