JPH07179394A - Oxadiazole compound and its production - Google Patents

Abstract

PURPOSE:To obtain a new compound useful as a material for organic electroluminescent devices such as a luminescent material or electron transfer material, having stable film formability, and hard to crystallize even if stored for a long period of time. CONSTITUTION:This compound is represented by formula I [A1-A4 each is a (substituted) aromatic hydrocarbon or a (substituted) aromatic heterocycle; X is H or F; R1 and R2 are each H, a halogen, a (substituted) alkyl or an alkoxyl] and is obtained by reaction between an acid chloride compound of formula II and a tetrazole compound of formula III [A is a (substituted) aromatic hydrocarbon or a (substituted) aromatic heterocycle, corresponding to A1 or A2, respectively].

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel oxadiazole compound useful as a material for an organic electroluminescence device, a novel acid chloride compound which is a synthetic intermediate thereof, and a method for producing them.

[0002]

Various oxadiazole compounds are known as materials for organic electroluminescence devices. For example, the Chemical Society of Japan, 1991, (11), p. 1540-154
8 describes an example using an oxadiazole compound as a light emitting material and an electron transporting material. However, there are still problems with the stability of the thin film, and high brightness,
No highly reliable organic electroluminescent device has been obtained. Crystallization of organic materials is mentioned as the cause. In particular, the oxadiazole compounds used up to now have a large defect in the stability of the film, because an amorphous film cannot be obtained or even if it is obtained, it is crystallized by long-term storage. Therefore, there has been a demand for a material having a better film forming property and less likely to be crystallized.

[0003]

The present invention has a stable film-forming property as a material for an organic electroluminescence device, is useful as a light emitting material, an electron transporting material and the like, and is particularly difficult to crystallize even after long-term storage. New oxadiazole compounds,
It is an object to provide a novel acid chloride which is a synthetic intermediate thereof and a method for producing them.

[0004]

According to the present invention, the following general formula (I)

[Chemical 1] (In the formula, A _{1 to} A ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, which may be the same or different. X is a hydrogen atom. Or a fluorine atom, and R ₁ and R _{2 each} represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group). The following general formula (II) (Chemical formula 2)

[Chemical 2] (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. ) And an acid chloride compound represented by the following general formula (III)
Or general formula (IV)

[Chemical 3]

[Chemical 4] (In the formula, A represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, and corresponds to A ¹ and A ² in the following general formula (I)). Reaction with a tetrazole compound represented by the following general formula (I)

[Chemical 1] (In the formula, A _{1 to} A ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, which may be the same or different. X is a hydrogen atom. Or a fluorine atom, and R ₁ and R _{2 each} represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group). A method for producing an oxadiazole compound is provided, and thirdly, the following general formula (I
I) (Chemical formula 2)

[Chemical 2] (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. And an acid chloride compound represented by the following general formula (V)

[Chemical 5] (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. ) Is treated with a halogenating agent, the following general formula (II) (Chemical formula 2)

[Chemical 2] (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. The method for producing the acid chloride compound represented by

As a result of intensive studies to solve the above problems, the present inventors have found that an oxadiazole compound having a specific structure is effective, and have completed the present invention. In the general formula (I), the aromatic hydrocarbon group or aromatic heterocyclic group applied to A ^{1 to} A ⁴ is styryl, phenyl, biphenyl, terphenyl, naphthyl, anthryl, acenaphthenyl, fluorenyl, phenanthryl. , Indenyl, pyrenyl, pyridyl, pyrimidyl, furanyl, pyronyl, thiophenyl, quinolyl, benzofuranyl, benzothiophenyl,
Examples thereof include indolyl, carbazolyl, benzoxazolyl, quinoxalyl, benzimidazolyl, pyrazolyl, dibenzofuranyl, dibenzothiophenyl, oxazolyl and oxadiazolyl groups.

These aromatic hydrocarbon groups or aromatic heterocyclic groups further include one or more halogen atom, hydroxyl group, cyano group, nitro group, amino group, trifluoromethyl group,
An alkyl group having 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms,
C1-C12, preferably C1-C6 alkoxy, aryloxy, phenyl, styryl, naphthyl, thiophenyl, aralkyl, biphenyl, bithiophenyl, furanyl, bifuranyl, pyronyl, bipyronyl It may have a substituent such as a group.

The oxadiazole compound of the present invention represented by the general formula (I) can be produced by the following method. That is, the formula (II) (Formula 2)

[Chemical 2] (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. ) And an acid chloride compound represented by the following general formula (III) (formula 3) or general formula (IV) (formula 4)

[Chemical 3]

[Chemical 4] (In the formula, A represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, and corresponds to A ¹ and A ² in the general formula (I)). Obtained by reacting with the represented tetrazole compound.

The tetrazole compound represented by the general formula (III) (formula 3) and the general formula (IV) (formula 4) used here can be produced by a conventionally known method. For example, S
It can be synthesized by the method described in synthesis 71 (1973). In addition, the general formula (II) (formula 2) and the general formula (II
I) (Chemical Formula 3) or the reaction with the general formula (IV) (Chemical Formula 4) is described in R.I. D. It is performed according to the oxadiazole synthesis method of Huisgen et al. For example, Angew. Che
m. , 72, 366 (1960), Chem. Be
r. , 93, 2106 (1960), Tetrahed.
ron, 11, 241 (1960), Chem. Be
r. , 98, 2966 (1965).

The acid chloride compound represented by the general formula (II) (Chemical formula 2) is novel, and as described above, it is an intermediate compound for the synthesis of the oxadiazole compound represented by the general formula (1) (Chemical formula 1). It is useful as a body. The synthesis is carried out by the following general formula (V)

[Chemical 5] (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. ) Is treated with a halogenating agent. As the halogenating agent used in the present invention, phosphorus pentachloride, phosgene, etc. are used.

The oxadiazole compound represented by the general formula (I) of the present invention is particularly excellent as a constituent component of an organic electroluminescent device. For example, a thin film is formed by a vacuum vapor deposition method, a solution coating method or the like, and an anode and a cathode are formed. The element can be obtained by directly or indirectly sandwiching with.

Specific examples of the oxadiazole compound represented by the general formula (I) according to the present invention are shown in Table 1.

[Table 1]

[0012]

【Example】

Example 1 Synthesis of 4,4 ′-(hexafluoroisopropylidene) diphthalic acid chloride {formula (VI) (formula 6)}

[Chemical 6] 10 g of 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride, 10.5 g of phosphorus pentachloride and 6 ml of phosphorus oxychloride were placed in a reaction flask and heated under reflux for 25 hours to change to a solution state. After that, phosphorus oxychloride produced by the reaction and unreacted phosphorus pentachloride are removed by distillation, 30 ml of dichloromethane is added, insoluble matters are removed by filtration, and then the solvent is removed to obtain a crude product 1
1 g was obtained in oil form. Then cyclohexane 30m
It was dissolved in 1 liter by heating, 50 ml of n-hexane was added, and the mixture was allowed to stand, then the oily precipitate was taken out by decantation, washed with n-hexane, and then dried to obtain 6.8 g of the desired product (yield 55%. ) Got. This is a colorless oily substance, and its infrared absorption spectrum was measured by applying it to a salt plate, which was 1790 cm ^-1 and 1745 cm ^-1.
Had a peak of CO stretching vibration due to acid chloride.

Example 2 Compound No. Synthesis of 1, 4,4 '-(hexafluoroisopropylidene) diphthalic acid chloride obtained in Example 1 4.23 g, 5-phenyl-1H tetrazole 7.31 g, and 45 ml of dry pyridine as a solvent were used in a reaction flask. The mixture was heated under reflux for 45 hours. After allowing to cool, 160 ml of water was added, and the precipitate was filtered and washed with water to obtain 3.7 g of a crude product. Further, using chloroform / THF = 19/1 (vol) as a developing solvent, purification was performed by column chromatography, and chloroform / THF = 33/1 (vo) as a developing solvent.
The product was purified twice by column chromatography using l) to obtain 2.5 g of the desired product (yield 34%). This product is colorless, and cyclohexane / toluene = 1/1 (vo
The melting point of the product recrystallized from l) was 133 ° C. The infrared absorption spectrum (KBr tablet method) is shown in FIG.

[Table 2] From the above, the compound No. It was confirmed that 1 was obtained.

Example 3 (Synthesis of Compound No. 4) 1.32 g of 4,4 '-(hexafluoroisopropylidene) diphthalic acid chloride obtained in Example 1
(Biphenyl-4-yl) -1H tetrazole 3.18
g and 30 ml of dry pyridine as a solvent were used, and the mixture was heated under reflux in the reaction flask for 45 hours. After cooling down, methanol 7
0 ml was added, and the precipitate was filtered and washed with methanol to obtain 0.59 g of a crude product. Further, using chloroform / THF = 19/1 (vol) as a developing solvent, purification was carried out twice by column chromatography, and further using chloroform / THF = 33/1 (vol) as a developing solvent, purification was carried out by column chromatography, Target 0.51
g (yield 18%) was obtained. This product was colorless and the product recrystallized from cyclohexane / toluene = 1/1 (vol) did not show a clear melting point. The infrared absorption spectrum (KBr tablet method) is shown in FIG.

[Table 3] From the above, the compound No. It was confirmed that 4 was obtained.

Example 4 (Synthesis of compound No. 8) 1.29 g of 4,4 ′-(hexafluoroisopropylidene) diphthalic acid chloride obtained in Example 1
(Naphthyl-2-yl) -1H tetrazole 2.28
g, and 30 ml of dry pyridine as a solvent, the mixture was heated under reflux in the reaction flask for 73 hours. After cooling, it was evaporated to dryness to obtain 3.77 g of a crude product. This was purified by column chromatography using the developing solvent chloroform / THF = 19/1 (vol). Further, the product was purified by column chromatography twice using chloroform / THF = 33/1 (vol) as a developing solvent to obtain the desired product 0.67.
g (yield 27%) was obtained. This product was colorless and the product recrystallized from cyclohexane / toluene = 1/1 (vol) did not show a clear melting point. The infrared absorption spectrum (KBr tablet method) is shown in FIG.

[Table 4] From the above, the compound No. It was confirmed that 8 was obtained.

(Evaluation of Stability of Evaporated Film) Compound No. 1, No. 4, No. 8 and the following compounds (VII) to (X) (Chemical formula 7) to (Chemical formula 1)
Each of the oxadiazole compounds represented by 0) was formed on a glass substrate by a vacuum vapor deposition method to form a 500 Å film. Immediately after the production of this film and after storing it at room temperature for 6 months, it was observed visually or by an electron microscope.

[Chemical 7]

[Chemical 8]

[Chemical 9]

[Chemical 10] As a result, those using the compounds represented by the general formula (VII) and the general formula (VIII) were crystallized films immediately after vapor deposition, and became extremely cloudy after storage. The compounds using the compounds represented by the general formulas (IX) and (X) formed a uniform amorphous film immediately after vapor deposition, but after storage, they crystallized and became cloudy. On the other hand, the compound No. 1, N
O. 4, No. All of 8 formed an amorphous film, which was a transparent film even after storage, and it was confirmed by observation with an electron microscope that the film was a uniform amorphous film.

Application Example An anode made of indium tin oxide (ITO) having a size of 2 mm × 2 mm and 15 Ω / □ is formed on a glass substrate, and a diamine derivative represented by the following formula (XI) (Formula 11) is formed thereon. The hole transporting layer 400Å, the hole emitting layer 150Å made of a diamine derivative represented by the following formula (XII) (Formula 12), the compound No. Electron transport layer 40 consisting of 1
An MgAg electrode having a ratio of 0Å and 10: 1 was 2000Å, and each of the electrodes was formed by vacuum vapor deposition to manufacture an electroluminescent device. The degree of vacuum during vapor deposition is 1 × 10 ⁻⁶ Torr, and the substrate temperature is room temperature. When a direct current power supply was connected to the anode and cathode of the element thus manufactured through a lead wire, the applied voltage was 9 V at a current density of 30 mA / cm ² .
The clear blue-white luminescence was confirmed over a long period of time. In addition, clear luminescence was confirmed in this device even after storage for 3 months.

[Chemical 11]

[Chemical 12]

[0014]

EFFECTS OF THE INVENTION The oxadiazole compound of the present invention can easily form a stable amorphous film by vapor deposition or solvent coating, is hard to be crystallized, and has very good storage stability and reliability. It is useful as a material for a high organic electroluminescence device. Moreover, according to this invention, the novel acid chloride compound which is a synthetic intermediate of this oxadiazole compound, and the advantageous manufacturing method of these oxadiazole compounds and acid chloride compounds can be provided.

[0015]

[Brief description of drawings]

1 shows the compound NO. 1 in Table 1 obtained in Example 2. FIG. 1 is an infrared absorption spectrum chart of the oxadiazole compound of the present invention of No. 1 (KBr tablet method).

FIG. 2 shows the compound No. 1 in Table 1 obtained in Example 3. FIG. 4 is an infrared absorption spectrum chart of the oxadiazole compound of the present invention of No. 4 (KBr tablet method).

FIG. 3 shows compound No. 1 in Table 1 obtained in Example 4. 8 is an infrared absorption spectrum chart of the oxadiazole compound of the present invention of No. 8 (KBr tablet method).

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication C07D 413/04 213 // C09K 11/06 Z 9159-4H (72) Inventor Nozomu Tamoto Tokyo Ricoh Co., Ltd. 1-3-3 Nakamagome, Ota-ku

Claims (4)

[Claims] 1. The following general formula (I) (Chemical formula 1) (In the formula, A _{1 to} A ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, which may be the same or different. X is a hydrogen atom. Or a fluorine atom, and R ₁ and R _{2 each} represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group). 2. The following general formula (II) (Chemical formula 2) (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. ) And an acid chloride compound represented by the following general formula (III)
Or general formula (IV) (Chemical formula 4) [Chemical 4] (In the formula, A represents a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, and corresponds to A ¹ and A ² in the following general formula (I)). Reaction with a tetrazole compound represented by the following general formula (I) (In the formula, A _{1 to} A ₄ each represent a substituted or unsubstituted aromatic hydrocarbon group or a substituted or unsubstituted aromatic heterocyclic group, which may be the same or different. X is a hydrogen atom. Or a fluorine atom, and R ₁ and R _{2 each} represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group). Process for producing oxadiazole compound. 3. The following general formula (II) (Chemical Formula 2) (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. ) An acid chloride compound represented by: 4. The following general formula (V) (Chemical formula 5) (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. ) Is treated with a halogenating agent, the following general formula (II) (Chemical Formula 2) (In the formula, X represents a hydrogen atom or a fluorine atom.
R ₁ and R ₂ represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group or an alkoxy group. The manufacturing method of the acid chloride compound represented by these.