JPH0662866B2 - Novel styryl compound and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel styryl compound and a method for producing the same.

INDUSTRIAL APPLICABILITY The styryl compound of the present invention can be used for electrophotographic photoreceptors, fluorescent brightening dyes and the like, and is particularly useful as a material for electrophotographic photoreceptors having excellent sensitivity and durability.

[Problems to be Solved by Prior Art and Invention]

In recent years, the development of electrophotographic copying machines and printers has been remarkable, and various types and types of models have been developed according to the application, and correspondingly, a wide variety of photoconductors have been developed. It's starting.

Conventionally, inorganic compounds have been mainly used as electrophotographic photoreceptors from the viewpoint of sensitivity and durability. Examples of these inorganic compounds include zinc oxide, cadmium sulfide,
Examples include selenium. However, these often use harmful substances, and the disposal thereof becomes a problem and causes pollution. Further, when using selenium having a good sensitivity, it is necessary to form a thin film on a conductive substrate by a vapor deposition method or the like, resulting in poor productivity and high cost. In recent years, amorphous silicon has been attracting attention as a pollution-free inorganic photoconductor, and research and development thereof have been advanced. However, these are also excellent in sensitivity, but since the plasma CVD method is mainly used at the time of forming a thin film, the productivity is extremely poor, and the photoreceptor cost and the running cost are large.

On the other hand, organic photoconductors have the advantage of being incinerable and non-polluting, and many of them can be formed into a thin film by coating and are easy to mass produce. Therefore, it has an advantage that the cost can be significantly reduced and various shapes can be processed according to the application. However, with respect to the organic photoconductor, problems remain in its sensitivity and durability, and the emergence of a highly sensitive and highly durable organic photoconductor is strongly desired.

Various methods have been proposed as means for improving the sensitivity of the organic photoconductor, but at present, a function-separated photoconductor mainly having a two-layer structure in which the functions are separated into a charge generation layer and a charge transport layer has become mainstream. There is. For example, the charges generated in the charge generation layer by exposure are injected into the charge transport layer, transported through the charge transport layer to the surface, and the surface charge is neutralized to form an electrostatic latent image on the surface of the photoreceptor. To be done. Compared to the single-layer type, the function-separated type has a smaller possibility of trapping the generated charges, and each layer can efficiently transport the charges to the surface of the photoconductor without hindering the function of each layer (US Patent No. 2803541
issue).

As the organic charge generating material used in the charge generating layer, a compound that absorbs energy of irradiated light and efficiently generates charges is used. For example, an azo pigment (Japanese Patent Laid-Open No. 54-14967). ), Metal-free phthalocyanine pigments (JP-A-60-143346), metal phthalocyanine pigments (JP-A-50-16538), and squarylium salts (JP-A-SHO).
53-27033) and the like.

As the charge transport material used in the charge transport layer, it is necessary to select a compound having a high charge injection efficiency from the charge generation layer and a high charge mobility in the charge transport layer.
To do so, compounds with low ionization potential,
A compound in which radical cations are easily generated is selected, for example, a triarylamine derivative (JP-A-53-47260), a hydrazone derivative (JP-A-57-101844),
Oxadiazole derivative (JP-B-34-5466), pyrazoline derivative (JP-B-52-4188), stilbene derivative (JP-A-58-198043), triphenylmethane derivative (JP-B-45-555) Gazette) etc. have been proposed.

However, these charge mobilities are smaller than those of inorganic substances, and the sensitivity is still unsatisfactory, and further improved materials have been demanded.

One of the objects of the present invention is to provide a novel styryl compound which is a charge transport material that solves the drawbacks of conventional electrophotographic photoreceptors, and another object of the present invention is to provide the styryl compound. To provide a manufacturing method of.

[Means for Solving the Problems]

The present inventors have completed the present invention as a result of earnest research to achieve the above object.

That is, the present invention is represented by the general formula (1) (In the formula, R ₁ represents a hydrogen atom or a methyl group, (R represents a p-phenylene group, and R ₃ and R ₄ are the same or different and represent an alkyl group or a phenyl group.). The present invention further provides a styryl compound represented by the general formula (2) (Wherein R ₁ is the same as the above-mentioned general formula (1) and R ₅ is a lower alkyl group), and a benzenephosphonate ester represented by the general formula (3) (Wherein R ₂ is the same as in the general formula (1)) and a carbonyl compound represented by the general formula (1) is reacted to provide a method for producing a styryl compound represented by the general formula (1). .

R _{5 of the} benzenephosphonate represented by the general formula (2)
Is a lower alkyl group, an alkyl group having 1 to 4 carbon atoms,
Of these, a methyl group and an ethyl group are preferable. This general formula (2)
The benzenephosphonate represented by the general formula (4) (Wherein R ₁ is the same as in the general formula (1) and X represents a halogen atom.) And a trihalogenated compound can be reacted with a trialkyl phosphite.

Here, R ₁ is a hydrogen atom or a methyl group, and such a compound is easy to produce.

R _{2 of the} carbonyl compound represented by the general formula (3) is (R represents a p-phenylene group, and R ₃ and R ₄ are the same or different and represent an alkyl group or a phenyl group.). ) Is.

A styryl compound represented by the general formula (1) can be obtained by reacting the benzenephosphonate ester represented by the general formula (2) with the carbonyl compound represented by the general formula (3). The reaction can be carried out in the presence of a base in a polar solvent in the temperature range from room temperature to the boiling point of the solvent used.

Examples of the base used in the present invention include sodium hydroxide, potassium hydroxide, sodium methylate, sodium ethylate, potassium-t-butoxide, sodium amide, sodium hydride, potassium hydride, lithium diisopropylamide and the like. You can

As the reaction solvent, for example, methanol, ethanol,
Alcohol solvents such as isopropanol; ether solvents such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dioxane, tetrahydrofuran; benzene, toluene,
Aromatic solvents such as xylene; N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone and the like can be used.

The reaction is a benzenephosphonate represented by the general formula (2), an equivalent amount of a carbonyl compound represented by the general formula (3),
Equivalent or excess equivalents of a base and a solvent are mixed at the same time and reacted at a predetermined temperature, or first, the benzenephosphonate represented by the general formula (2) is dissolved in a solvent, and then the base and the general formula are used. The carbonyl compound represented by (3) is sequentially added and reacted at a predetermined temperature.

After completion of the reaction, pour in a large amount of water or a saturated aqueous solution in which a salt is dissolved, and collect the obtained solid, or dissolve the obtained solid in any organic solvent and fractionate, and distill off the organic solvent. As a result, the styryl compound represented by the general formula (1) can be obtained in high yield.

Specific examples of the styryl compound represented by the general formula (1) in the present invention obtained as described above include those represented by the following formulas, but the present invention is not limited thereto.

All of these styryl compounds are soluble in ordinary organic solvents and can be used for electrophotographic photoreceptors, fluorescent brightening dyes and the like. In particular, when it is used as a charge transporting material for an electrophotographic photosensitive member, it is possible to increase its sensitivity and durability.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

Example 1 1,2,4-Tris (β- (pN, N-diethylaminostyryl) benzene (Synthesis of Exemplified Compound (6)) 1 equipped with a stirrer, a cooling pipe, a nitrogen introducing pipe, and a thermometer
In a 4-necked flask, 5 g (9.5 mmol) of diethyl phosphonate synthesized from 1,2,4-tris (bromomethyl) benzene and 300 m of ethylene glycol dimethyl ether.
Was added and dissolved, and 3.0 g of sodium hydride was added thereto at room temperature. After stirring for 30 minutes, 50 g of an ethylene glycol dimethyl ether solution containing 5 g (28.5 mmol) of pN, N-diethylaminobenzaldehyde was added dropwise at room temperature. After the dropping was completed, the temperature was raised to 85 ° C. and the mixture was stirred at that temperature for 5 hours.

Then the reaction mixture was cooled to room temperature and poured into 2 water. Further, ethyl acetate 1 was added and mixed well, and the ethyl acetate layer was separated. The ethyl acetate solution was washed twice with water and dried over anhydrous sodium sulfate. After drying, ethyl acetate was distilled off under reduced pressure to obtain a yellow solid, which was purified once by a silica gel column (ethyl acetate) and recrystallized from isopropanol to obtain 4.7 g of yellow crystals (yield 83%).

Melting point 71-73 ° C Elemental analysis (C ₄₂ H ₅₁ N ₃ ) Calculated value (%) Measured value (%) C 84.42 84.31 H 8.54 8.50 N 7.04 7.19 Further, NMR (60 MHz) data is shown in Fig. 1.

Examples 2 to 5 Exemplified compounds (7), (8), (9) and (11) were prepared in the same manner as in Example 1 except that corresponding carbonyl compounds were used instead of pN, N-diethylaminobenzaldehyde. Was synthesized, and the melting point and elemental analysis values were measured.

The results are shown in Table-1.

Example 6 1,2,4-Tris (β- (pN, N-dimethylaminostyryl)) benzene (Synthesis of Exemplified Compound (5)) 1,2,4-Tris (bromomethyl) was placed in the same apparatus as in Example 1. ) 5 g of diethyl phosphonate synthesized from benzene (9.
5 mmol), pN, N-dimethylaminobenzaldehyde
4.25 g (28.5 mmol), dimethylformamide 500 m
, 28% methanol solution of sodium methoxide 7m
Were mixed and reacted at 40 ° C. for 6 hours with stirring. Subsequent operations were performed in the same manner as in Example 1 by performing silica gel column (ethyl acetate) and recrystallization (toluene) to obtain yellow crystals (yield 83%).

Melting point 79-80 ° C Elemental analysis (C ₃₆ H ₃₉ N ₃ ) Calculated value (%) Measured value (%) C 84.21 84.01 H 7.06 7.66 N 8.19 8.33 Example 7 Instead of pN, N-dimethylaminobenzaldehyde Exemplified compound (10) was synthesized in the same manner as in Example 6 except that the carbonyl compound was used (yield 72%), and the melting point and elemental analysis values were measured. The results are shown below.

Melting point 62.5 to 64 ° C Elemental analysis (C ₄₅ H ₅₇ N ₃ ) Calculated value (%) Measured value (%) C 84.51 84.59 H 8.92 8.80 N 6.57 6.61

[Brief description of drawings]

FIG. 1 shows the NMR spectrum of the exemplified compound (6) obtained in Example 1.

 ─────────────────────────────────────────────────── ─── Continued Front Page (56) References JP-A-62-11772 (JP, A) JP-A-2-219809 (JP, A) US Patent 3378604 (US, A) US Patent 3836602 (US, A) West Germany published 1468976 (DE, A) STSINTILL, ORG, Lyum infory Vol. 3 P. 42-50 (1974) Helv. Chim. Acta Vol. 52 No. 8 P. 2521-54 (1969) J. Chem. Soc. Perkin Trans. I Vol. 1 No. 7 P. 1900-8 (1981)

Claims (2)

[Claims] 1. A styryl compound represented by the general formula (1). (In the formula, R ₁ represents a hydrogen atom or a methyl group, (R represents a p-phenylene group, and R ₃ and R ₄ are the same or different and represent an alkyl group or a phenyl group.). ) 2. A general formula (2) (Wherein R ₁ is the same as the above-mentioned general formula (1) and R ₅ is a lower alkyl group), and a benzenephosphonate ester represented by the general formula (3) The method for producing a styryl compound according to claim 1, wherein a carbonyl compound represented by the formula (wherein R ₂ is the same as in the general formula (1)) is reacted.