JPS6118943B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel fluoran derivative and a method for producing the same.

The fluoran compound of the present invention is particularly useful as a dye precursor for recording materials such as pressure-sensitive recording sheets, heat-sensitive recording sheets, and current-carrying heat-sensitive recording sheets. Electron beam recording sheets, electrostatic recording sheets, photosensitive printing plates, stamping materials, type ribbons,
It is a compound that can also be used in ballpoint pen inks, crayons, etc.

Conventionally, fluoran compounds have been used as dye precursors for recording materials, but they have drawbacks such as the fluoran compounds themselves being unstable in the atmosphere, and the dyes produced from them having poor fastness to light, moisture, etc. It had

In addition, as a method for producing a fluoran compound, 2-(4-dialkylamino-2
-Hydroxybenzoyl)benzoic acid [A] and an aminophenol derivative [B] are condensed in a dehydrating agent such as sulfuric acid.

(In the formula, R ₁ , R ₂ and R ₃ are the above general formula []
(R ₄ represents a hydrogen atom, an acyl group, or a lower alkyl group) However, in the above method, especially when R ₃ is a halokene-substituted alkyl group or an alkoxy-substituted alkyl group, a sub-alkyl group may be present during the reaction. Many reactions occur and the yield is very poor, making it unsuitable for industrial production.

Therefore, the first object of the present invention is to provide a novel fluoran derivative which is particularly excellent as a dye precursor for recording materials, and the second object of the present invention is to provide a novel method for producing a fluoran derivative. It is.

The present inventors have discovered that a novel fluorane derivative represented by the following general formula [] is stable in the atmosphere and is a colorless or slightly colored powder. It develops a black color almost instantaneously when it comes into close contact with a receptor substance, and has excellent performance as a dye precursor for recording materials without deteriorating its coloring performance due to coloration or decomposition during storage. I found it.

[In the formula, R ₁ and R ₂ represent an alkyl group having 5 or less carbon atoms, and R ₃ represents an alkyl group having 10 or less carbon atoms, a halogenated alkyl group, or an alkoxyalkyl group. ] Furthermore, the present inventors have discovered that the fluoran derivative represented by the general formula [] can be easily produced in high yield by reacting the fluoran derivative represented by the following general formula [] with the alkylating agent represented by the general formula []. I found out what you can get.

R ₃ -Z [] [In the formula, R ₁ and R ₂ are an alkyl group having 5 or less carbon atoms, R ₃ is an alkyl group, a halogenated alkyl group, or an alkoxyalkyl group having 10 or less carbon atoms, and Z is an alkyl group having 10 or less carbon atoms. Chlorine atom, R ₃ OSO ₃ − or R ₄ SO ₃ − (R ₄
represents a phenyl group, a paratolyl group, or an alkyl group having 5 or less carbon atoms). ] The fluoran derivative [ ] used as a raw material in the present invention is 2-(4-dialkylamino-2-
It is obtained by reacting hydroxybenzoyl)benzoic acid and an aminophenol derivative in the presence of a condensing agent.

Next, this fluoran derivative [] and the alkylating agent [] are reacted together with an additive such as a base in a suitable solvent.

In particular, the production method of the present invention is extremely useful when R ₃ is a halogen-substituted alkyl group or an alkoxy-substituted alkyl group.

Typical compounds of the fluoran derivatives used as raw materials in the present invention include 2-amino-3-chloro-6-diethylaminofluoran, 2-amino-3-chloro-6-dibutylaminofluoran, and 2-amino-3-chloro-6-dibutylaminofluoran. -3-chloro-6-dimethylaminofluorane, 2-amino-3-chloro-6-diethylaminofluorane, 2-amino-3-chloro-6-dimethylaminofluorane, 2-amino-3-bromo-6 -diethylaminofluorane, etc.

Preferred examples of the alkylating agent of the present invention include:
Dimethyl nitrate, diethyl sulfate, butyl bromide, hexyl bromide, octyl iodide, 1-chloro-3-bromopropane, 2-ethoxyethyl p-toluenesulfonate, 2-phenyloxyethyl benzenesulfonate, methane Examples include 2-butyloxyethyl sulfonate.

As the solvent used in the present invention, common organic solvents such as methanol, ethanol, isopropanol, methyl cellosolve, ethyl cellosolve, benzene, toluene, xylene, dimethylformamide, acetone, and methyl ethyl ketone are used.

The additives used in the present invention include potassium carbonate, sodium carbonate, magnesium oxide, calcium oxide, triethylamino, potassium iodide, potassium bromide, sodium iodide, sodium bromide, tetrabutylammonium iodide, and tetrabromide. Butylammonium etc.

The general method for producing the present invention is to use 1.0 to 1.0 mol of alkylating agent per 1.0 mol of fluoran derivative [].
Using 10.0 mol, the reaction is carried out in a solvent (volume 1 to 20 times the weight of the fluorane derivative) in the presence of additives at a temperature of 60 to 150°C for 4 to 40 hours. After cooling, the reactant was poured into water, and if crystals precipitated, they were removed, and if no crystals precipitated, they were extracted with a solvent, the solvent was distilled off, and then toluene, benzene-ethyl acetate, methanol, hexane were added. By recrystallizing from etc., the desired fluoran derivative represented by the general formula [] is obtained.

An example of synthesis of the fluoran derivative [] used as a raw material in the present invention will be shown.

Synthesis Example 1 Synthesis of 2-amino-3-chloro-6-diethylaminofluorane 31.3 g of 2-(4-diethylamino-2-hydroxy-benzoyl)benzoic acid and 18.6 g of 3-chloro-4-acetylaminophenol. 35ml
32-45 in the presence of 95% sulfuric acid and 35ml of 20% oleum
The reaction was carried out for 6 hours at a temperature of ℃, and the resulting reaction product was
After stirring in 350 ml of water for 1 hour at a temperature of 75-80°C, an aqueous sodium hydroxide solution (120 g of sodium hydroxide dissolved in 200 ml of water) is added while cooling. The precipitated crystals are collected and washed with dilute alkaline water, water, and methanol-water. The crystals were dried to obtain 36.8 g of deep purple 2-amino-3-chloro-6-diethylaminofluorane. Melting point 190
-194℃ Synthesis Example 2 Synthesis of 2-amino-3-chloro-6-diethylaminofluorane 31.3 g of 2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid and 22.7 g of o-acetyl-3-chloro- 4-acetylaminophenol is reacted in the presence of 100 ml of 95% sulfuric acid at a temperature of 35-55° C. for 9 hours. Next, the same treatment as in Synthesis Example 1 was carried out to obtain a deep purple 2-amino-3-chloro-6-
35.0 g of diethylaminofluorane was obtained. melting point
190-194°C Among the methods for carrying out the present invention, typical manufacturing methods are shown in the following Examples.

Example 1 (Production method of 2-γ-phenoxypropylamino-3-chloro-6-diethylaminofluoran) 4.2 g of 2-amino-3-chloro-6-diethylaminofluorane and γ-phenoxy bromide propyl
Add 5.0g to 10ml of dimethylformamide,
Furthermore, add 1.4 g of potassium carbonate. This is 100−
After reacting at a temperature of 120° C. for 8 hours with stirring, the reaction mixture was poured into 100 ml of water and extracted with ethyl acetate.
After ethyl acetate was distilled off under reduced pressure, the residue was recrystallized from benzene-n-hexane to obtain 2.7 g of almost colorless 2-γ-phenoxypropylamino-3-chloro-6-diethylaminofluorane. .
Melting point: 133-135℃ A solution of this fluoran compound in benzene is completely colorless, but when it comes into contact with an electron-accepting substance such as acid clay, zinc 3,5-di-t-butylsalicylate, or bisphenol A, it immediately turns black. It developed color.

Example 2 (Production method of 2-β-methoxyethylamino-3-chloro-6-diethylaminofluoran) 4.2 g of 2-amino-3-chloro-6-diethylaminofluoran and 6.0 g of β-methoxyethyl bromide
and into 10 ml of dimethylformamide, and then add 1.4 g of potassium carbonate. This is allowed to react under stirring at a temperature of 70-90°C for 16 hours. After cooling, the same treatment as in Example 1 was carried out to obtain almost colorless 2-β.
2.5 g of -methoxyethylamino-3-chloro-6-diethylaminofluorane was obtained. Melting point 208−
210°C This fluoran compound immediately developed a black color upon contact with an electron-accepting substance.

Example 3 (2-β-isobutyloxyethylamino-3
-Production method of chloro-6-diethylaminofluoran) Add 4.2 g of 2-amino-3-chloro-6-diethylaminofluoran and 4.2 g of β-isobutyloxyethyl bromide to 10 ml of toluene, and add 1.4 g of potassium carbonate. Add g. This is reacted at a temperature of 110° C. for 20 hours with stirring. Next, the same treatment as in Example 1 was carried out to obtain 3.1 g of almost colorless 2-β-isobutyloxyethylamino-3-chloro-6-diethylaminofluorane. Melting point 144−
146°C This fluoran compound immediately developed a black color upon contact with the electron-accepting substance.

Example 4 (Method for producing 2-β-butyloxyethylamino-3-chloro-6-diethylaminofluoran) 4.2 g of 2-amino-3-chloro-6-diethylaminofluoran and 5.4 g of β-butyloxyethyl bromide
g into 10 ml of methyl ethyl ketone, and then add 1.4 g of potassium carbonate. This is reacted at a temperature of 80-90°C for 40 hours with stirring. Next, Example 1
The same treatment as above was carried out to obtain 3.0 g of almost colorless 2-β-butyloxyethylamino-3-chloro-6-diethylaminofluorane. Melting point 114−116
℃ This fluoran compound immediately developed a black color upon contact with an electron-accepting substance.

Example 5 (Production method of 2-β-ethoxyethylamino-3-chloro-6-diethylaminofluoran) 4.2 g of 2-amino-3-chloro-6-diethylaminofluoran and para-toluenesulfonic acid-2
-8.5g of ethoxyethyl and 8.4g of ethyl cellosolve
In addition to 0.6 g of magnesium oxide,
Sodium iodide 0.7g, triethylamine 0.5g
Add. After reacting this at a temperature of 110°C for 10 hours, the reaction product was poured into 80 ml of water and the precipitated crystals were collected. The obtained crude product was recrystallized from toluene/methanol to obtain 3.8 g of almost colorless 2-β-ethoxyethylamino-3-chloro-6-diethylaminofluorane. Melting point: 188-190°C This fluoran compound immediately developed a black color upon contact with an electron-accepting substance.

Example 6 (Method for producing 2-β-phenoxyethylamino-3-chloro-6-diethylaminofluoran) 4.2 g of 2-amino-3-chloro-6-diethylaminofluoran and β-phenoxyethyl methanesulfonate Add 10g to 10ml of ethanol,
Furthermore, add 1.4 g of potassium carbonate. This was reacted under stirring for 30 hours while heating and refluxing. Next, the same treatment as in Example 1 was carried out, and almost colorless 2-
β-Phenoxyethylamino-3-chloro-6-
2.6 g of diethylaminofluorane was obtained. melting point 229
-231°C This fluoran compound immediately developed a black color upon contact with the electron-accepting substance.

Example 7 (Production method of 2-γ-chloropropylamino-3-chloro-6-diethylaminofluorane) 4.2 g of 2-amino-3-chloro-6-diethylaminofluorane and 1-chloro-3-bromopropane Add 14g of magnesium oxide to 8ml of isopropyl alcohol, and then add 0.4g of magnesium oxide. This was reacted under stirring for 15 hours while heating to reflux. Next, the same treatment as in Example 5 was carried out to obtain 3.1 g of almost colorless 2-γ-chloropropylamino-3-chloro-6-diethylaminofluorane.
Melting point: 158-160°C This fluoran compound immediately developed a black color upon contact with an electron-accepting substance.

Example 8 (2-β-chloroethylamino-3-chloro-
Method for producing 6-diethylaminofluorane) Add 4.2 g of 2-amino-3-chloro-6-diethylaminofluoran and 4.2 g of 1-chloro-2-bromoethane to 10 ml of ethanol, and then add 0.3 g of calcium oxide. . This was reacted under stirring for 30 hours while heating and refluxing. Next, the same treatment as in Example 5 was carried out to obtain almost colorless 2-β-
2.5 g of chloroethylamino-3-chloro-6-diethylaminofluorane was obtained. Melting point: 149-151°C This fluoran compound immediately developed a black color upon contact with an electron-accepting substance.

Example 9 (Production method of 2-butylamino-3-chloro-6-diethylaminofluoran) 4.2 g of 2-amino-3-chloro-6-diethylaminofluoran and 6.5 g of butyl p-toluenesulfonate were added to ethyl cellosolve. Add to 9ml,
Plus 0.6g of magnesium oxide, potassium iodide
Add 0.8 g and 0.3 g of tetrabutylammonium iodide. This is allowed to react at a temperature of 110°C for 27 hours. Next, the same treatment as in Example 5 was carried out to obtain 3.2 g of almost colorless 2-butylamino-3-chloro-6-diethylaminofluorane. Melting point 152−154
℃ This fluoran compound came into contact with an electron-accepting substance and immediately developed a black color.

Example 10 (Production method of 2-hexylamino-3-chloro-6-diethylaminofluorane) 4.2 g of 2-amino-3-chloro-6-diethylaminofluorane and 16.0 g of hexyl bromide were dissolved in 10 ml of dimethylformamide. Add 1.4g of potassium carbonate. This is reacted at a temperature of 110° C. for 10 hours with stirring. Next, the same treatment as in Example 1 was carried out to obtain almost colorless 2-hexylamino-3-
3.0 g of chloro-6-diethylaminofluorane was obtained. Melting point: 190-191°C This fluoran compound immediately developed a black color upon contact with an electron-accepting substance.

Next, a comparative example of synthesis using reaction formula (a) will be given.

Comparative Example 1 (Synthesis of 2-β-butyloxyethylamino-3-chloro-6-diethylaminofluorane) 3.1 g of 2-14-diethylamino-2-hydroxybenzoyl)benzoic acid and 3-chloro-4-β-
Butyloxyethylaminophenol 2.4g and
Add to 10 ml of 95% sulfuric acid, and add this to 10 ml of 95% sulfuric acid at a temperature of 65°C.
Allow to react under stirring for an hour.

Pour the reaction mixture into 50 ml of water and add an aqueous sodium hydroxide solution (12 g of sodium hydroxide dissolved in 20 ml of water). After performing ethyl acetate extraction, ethyl acetate is distilled off under reduced pressure. Recrystallization was performed with benzene-n-hexane to obtain 0.4 g of the same compound as that obtained in Example 7.

Comparative Example 2 (Synthesis of 2-β-ethoxyethylamino-3-chloro-6-diethylaminofluorane) 3.1 g of 2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid and 3-chloro-4-β
-2.2g of ethoxyethylaminophenol and 5
ml of 95% sulfuric acid and 5 ml of 20% oleum are added to react at a temperature of 18-35° C. for 30 hours with stirring. Next, the same treatment as in Comparative Example 1 was performed, and Example 8
1.6 g of the same compound as obtained was obtained.

Comparative Example 3 (Synthesis of 2-γ-chloropropylamino-3-chloro-6-diethylaminofluorane) 3.1 g of 2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid and 3-chloro-4-γ
-2.3g of chloropropylaminoanisole and 5
ml of 95% sulfuric acid and 5 ml of 20% fuming sulfuric acid, and the mixture was reacted with stirring at a temperature of 30°C for 6 hours.
The reaction is carried out at a temperature of 100° C. for 9 hours with stirring.

Next, the same treatment as in Comparative Example 1 was performed to obtain 1.8 g of the same compound as that obtained in Example 10.

Comparative Example 4 (Synthesis of 2-γ-chloropropylamino-3-chloro-6-diethylaminofluorane) 3.1 g of 2-(4-diethylamino-2-hydroxybenzoyl)benzoic acid and 3-chloro-4-γ
-2.2 g of chloropropylaminophenol,
The mixture was added to 4 ml of 95% sulfuric acid and 3 ml of 30% fuming sulfuric acid and reacted at a temperature of 40 to 45° C. for 6 hours with stirring. Next, the same treatment as in Comparative Example 1 was carried out to obtain 2.0 g of the same compound as that obtained in Example 10.

As is clear from the results of the comparative examples, the production method of the present invention is extremely advantageous.

Claims (1)

[Claims] 1. Fluorane derivative represented by the following general formula [] [In the formula, R ₁ and R ₂ represent an alkyl group having 5 or less carbon atoms, and R ₃ represents an alkyl group having 10 or less carbon atoms, a chlorinated alkyl group, or an alkoxyalkyl group. ] 2. A method for producing a fluoran derivative represented by the general formula [], which comprises reacting a fluoran derivative represented by the following general formula [] with an alkylating agent represented by the general formula []. R ₃ −Z [] [In the formula, R ₁ and R ₂ are an alkyl group having 5 or less carbon atoms, R ₃ is an alkyl group having 10 or less carbon atoms, a chlorinated alkyl group, or an alkoxyalkyl group, Z
is a chlorine atom, R ₃ OSO ₃ - or R ₄ SO ₃ - (R ₄ represents a phenyl group, a paratolyl group, or an alkyl group having 5 or less carbon atoms.)