JPH0572901B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing an asymmetric squarerylium compound useful as a photoconductive material. [Prior Art] Many inorganic and organic substances are known as photoconductive materials for electrophotographic photoreceptors and the like. Among these, conventionally known organic photoconductive materials include bisazo pigments, trisazo pigments, phthalocyanine pigments, cyanines, and pyrylium pigments.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a method for producing a novel asymmetric squarerylium compound. [Means for solving the problem] As a result of intensive research, the present inventors have found 3.4
- Dichloro-3-cyclobutene-1,2-dione (squaric acid chloride) is reacted with an aniline derivative to obtain a chlorocyclobutenedione derivative, and this derivative is hydrolyzed to obtain a hydroxycyclobutenedione derivative; The inventors have discovered that an asymmetric squarerium compound can be easily obtained with high purity by reacting it with other aniline derivatives, and have completed the present invention. That is, the present invention is based on the general formula ()

[In the formula, R ₃ represents a hydrogen atom, a fluorine atom, a methyl group, or a hydroxyl group, and R ₁ and R ₂ represent a methyl group and _{R 2 an} ethyl group, a benzyl group, or a p-fluorobenzyl group. or p-chlorobenzyl group, or both represent an ethyl group or a benzyl group. ] The present invention provides a method for producing a squarerium compound shown in the following. Specific examples of the asymmetric squarerium compounds represented by the general formula () obtained by the production method of the present invention are shown below in terms of structural formulas.

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embedded image The production method of the present invention is shown by reaction scheme A and reaction scheme B below.

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〔Effect of the invention〕

The present invention provides a method for producing a novel asymmetric squarerium compound. According to the present invention, an asymmetric squarerium compound can be easily obtained with high purity. The squarylium compound of the present invention can be effectively used as an organic photoconductor such as an electrophotographic photoreceptor. Although various forms of electrophotographic photoreceptors can be considered, the squarerium compound of the present invention is particularly suitable for use in a charge generation layer in a functionally separated photoreceptor, that is, a photoreceptor composed of a charge generation layer and a charge transport layer. It is useful as a photoconductive material used as a photoconductive material. [Example] The present invention will be described below with reference to Examples. Example 1 3,4-dichloro-3-cyclobutene-1,2
- 3.00 g of dione and 2.65 g of aluminum chloride were stirred in 30 ml of methylene chloride while keeping the temperature below 5°C until the aluminum chloride was dissolved. To this, N, N
- 2.43 g of dimethylaniline was added dropwise over 30 minutes,
Thereafter, the mixture was kept at 5° C. or lower for 2.5 hours to react. After the reaction was completed, it was washed with 1M HCl and water, and then separated by column chromatography, and the following formula was obtained.

1.64 g (yield: 35%) of the product represented by the formula (a compound where R ₃ =H in the formula) was obtained. Next, 1.56 g of this compound was refluxed for 2 hours in a mixed solvent of 30 ml of glacial acetic acid and 6 ml of water, cooled to room temperature, separated, and the following formula

[Formula] Product (compound with R ₃ = H in the formula) 1.38
g (yield 96%) was obtained. Next, 0.45 g of this product and 0.57 g of N,N-dibenzylaniline were refluxed in 41 ml of butanol for 20.5 hours and separated to obtain blue crystals. This was washed with methanol and ether and then dried to obtain the product represented by the structural formula (6). Yield: 0.72g (yield 74%). Decomposition point: 250.5℃; Elemental analysis: C ₃₂ H ₂₈ N ₂ O ₂ C H N Calculated value (%) 81.33 5.97 5.93 Actual value (%) 81.40 5.98 5.95 Maximum absorption wavelength λ _nax : 628 nm (in CH ₂ Cl ₂ ). Example 2 3,4-dichloro-3-cyclobutene-1,2
- 3.36 g of dione and 3.20 g of aluminum chloride were stirred in 20 ml of methylene chloride while keeping the temperature below 5°C until the aluminum chloride was dissolved. Add 3.02 g of N-methyl-N-ethylaniline to this and 12 ml of methylene chloride.
was added dropwise over a period of 2 hours, followed by reaction by keeping the temperature below 5° C. for 2.5 hours. 1M after completion of response
- Washed with HCl, water. Next, it is separated by column chromatography, and the following formula is used:

1.78 g of the product represented by the formula (a compound where R ₁ = CH ₃ and R ₂ = C ₂ H ₅ in the formula)
(yield 32%). Next, 1.50 g of this compound, 30 ml of glacial acetic acid, and 4 ml of water.
After refluxing for 4 hours and cooling to room temperature, crystals were precipitated with a small amount of water, and the following formula was obtained.

1.18 g of the product represented by the formula (a compound where R ₁ = CH ₃ and R ₂ = C ₂ H ₅ in the formula)
(yield 85%). Next, 1.00 g of this product and 1.57 g of N,N-dimethylaniline were refluxed for 5 hours in 10 ml of butanol and 5 ml of toluene, and then separated to obtain blue-green crystals. After washing this with methanol and drying, the above structural formula (1) is obtained.
The product shown was obtained. Yield 1.04g (yield 72
%). Decomposition point: 228℃; Elemental analysis: C ₂₁ H ₂₂ N ₂ O ₂ C H N Calculated value (%) 75.42 6.63 8.38 Actual value (%) 75.41 6.65 8.34 Maximum absorption wavelength λ _nax : 629 nm (in CH ₂ Cl ₂ ); IR spectrum: Figure 1. Example 3 3,4-dichloro-3-cyclobutene-1,2
- 3.00 g of dione and 2.65 g of aluminum chloride were stirred in 30 ml of methylene chloride while keeping the temperature below 5°C until the aluminum chloride was dissolved. Add 2.73g of 3-dimethylaminophenol to this.
The mixture was added dropwise over 30 minutes, and then the temperature was kept below 5°C for 2.5 hours to react. After the reaction was completed, it was washed with 1M HCl and water, and then separated by column chromatography, and the following formula was obtained.

Product represented by [Formula] (compound where R ₃ =OH in the formula) 1.50
g (yield 30%) was obtained. Next, 1.50 g of this compound, 30 ml of glacial acetic acid, and 6 ml of water were refluxed for 2 hours, cooled to room temperature, and separated.

1.33 g of the product represented by the formula (compound where R ₃ =OH in the formula) (yield
96%). Next, 1.00 g of this product and 1.74 g of N-methyl-N-ethylaniline were refluxed in 85 ml of butanol for 20 hours and then separated to obtain blue-green crystals. This was washed with methanol and diethyl ether and then dried to obtain a product represented by the structural formula (19). yield
0.93g (yield 62%). Decomposition point: 243°C; Elemental analysis: C ₂₁ H ₂₂ NO ₃ Calculated value (%) 75.42 6.63 8.38 Actual value (%) 75.22 6.51 8.32 Maximum absorption wavelength λ _nax : 630 nm (in CH ₂ Cl ₂ ). Examples 4 to 24 Twenty-one types of squarylium compounds were synthesized in the same manner as in Example 1, except that the raw material aniline derivatives used were changed. Table 2 shows the synthesized squarerylium compound, its elemental analysis results, and the maximum absorption wavelength λ _nax in dichloromethane. Further, the IR spectrum of the compound (No. 22) obtained in Example 17 is shown in FIG.

【table】 [Brief explanation of the drawing]

FIGS. 1 and 2 are IR spectra of examples of the squarylium compound of the present invention.

Claims (1)

[Claims] 1 3,4-dichloro-3-cyclobutene-1,2-dione represented by the formula () [Formula] and the general formula () [Formula] (wherein R ₃ is a hydrogen atom, represents an elementary atom, methyl group or hydroxyl group) to produce chlorocyclobutenedione represented by the general formula () [Formula] (wherein R ₃ represents the same meaning as above). A derivative is obtained, and then the compound of the general formula () is hydrolyzed to obtain a hydroxycyclobutenedione derivative represented by the general formula () [Formula] (wherein R ₃ represents the same meaning as above). _A compound of the general formula () is a compound of the general formula () [Formula] (where R ₁ is a methyl group and _{R 2 is} an ethyl group, a benzyl group, a p-fluorobenzyl group, or a p-chlorobenzyl group). or both represent an ethyl group or a benzyl group). ) A method for producing a squarerium compound. 2 3,4-dichloro-3-cyclobutene-1,2-dione represented by the formula () [Formula] and the general formula () [Formula] (where R ₁ and R ₂ are R ₁ is a methyl group) R ₂ represents an ethyl group, a benzyl group, a p-fluorobenzyl group, or a p-chlorobenzyl group, or both represent an ethyl group or a benzyl group.) (In the formula, R ₁ and R ₂ have the same meanings as above.) A chlorocyclobutenedione derivative represented by the formula (wherein, R ₁ and R ₂ have the same meanings as above), and the compound of this general formula () is a compound of the general formula () [formula] (wherein, R ₃ is the same as above). Production of a squarylium compound represented by the general formula () (in which all symbols have the same meanings as above), characterized by reacting with an aniline derivative represented by Method.