Cyclic azine compound, material for organic electroluminescent element, electron transport material for organic electroluminescent element, and organic electroluminescent element

Abstract

The object of the present invention is to provide a cyclic azine compound having both excellent driving voltage characteristics and current efficiency characteristics. The target cyclic azine compound is a cyclic azine compound having a specific structure represented by formula (1). [Chemical 1]

Description

Technical Field

[0001] The present disclosure relates to a cyclic azine compound, a material for an organic electroluminescent element, an electron transport material for an organic electroluminescent element, and an organic electroluminescent element. Background Art

[0002] Organic electroluminescent elements are being actively developed for use not only in small displays but also in large televisions and lighting.

[0003] For example, Patent Document 1 discloses a cyclic azine compound having a specific substituent as a material for an organic electroluminescent element, which contributes to providing an organic electroluminescent element having excellent heat resistance, low driving voltage, and long life.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-280330 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, in recent years, market demands for organic electroluminescent elements have become increasingly stringent, and there is a demand for the development of materials having both excellent driving voltage characteristics and excellent current efficiency characteristics.

[0009] Here, although the organic electroluminescent device using the cyclic azine compound disclosed in Patent Document 1 exhibits excellent long life characteristics and current efficiency characteristics, further improvement in driving voltage characteristics is required.

[0010] One embodiment of the present disclosure is to provide a cyclic azine compound, an organic electroluminescent device material, and an electron transport material for an organic electroluminescent device, which have both excellent driving voltage characteristics and current efficiency characteristics.

[0011] Furthermore, another aspect of the present disclosure is to provide an organic electroluminescent element having both excellent driving voltage characteristics and excellent current efficiency characteristics.

[0012] Means for solving problems

[0013] According to one embodiment of the present disclosure, a cyclic azine compound represented by formula (1) is provided:

[0014] [Chemistry 1]

[0015]

[0016] In formula (1),

[0017] Ar 1is phenyl or 4-biphenyl;

[0018] Ar 2 is any one of the groups represented by formula (2-1) to (2-3);

[0019] [Chemistry 2]

[0020]

[0021] Ar 3 is a group represented by formula (3);

[0022] [Chemistry 3]

[0023]

[0024] In formula (3),

[0025] Ar 31 represents a hydrogen atom or any of the groups represented by formulae (2-1) to (2-3).

[0026] According to another aspect of the present disclosure, there is provided a material for an organic electroluminescent device including the cyclic azine compound.

[0027] According to another aspect of the present disclosure, there is provided an electron transport material for an organic electroluminescent device including the cyclic azine compound.

[0028] According to another aspect of the present disclosure, an organic electroluminescent device including the cyclic azine compound is provided.

[0029] Effects of the Invention

[0030] According to one embodiment of the present disclosure, a cyclic azine compound, an organic electroluminescent device material, and an electron transport material for an organic electroluminescent device having both excellent driving voltage characteristics and current efficiency characteristics can be obtained.

[0031] According to another aspect of the present disclosure, an organic electroluminescent element having both excellent driving voltage characteristics and excellent current efficiency characteristics can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent element including a cyclic azine compound according to one embodiment of the present disclosure.

[0033] Figure 2 This is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent element including a cyclic azine compound according to one embodiment of the present disclosure (Element Example-1).

[0034] Figure 3This is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent element including a cyclic azine compound according to one embodiment of the present disclosure (Element Example-2). DETAILED DESCRIPTION

[0035] Hereinafter, the cyclic azine compound according to one embodiment of the present disclosure will be described in detail.

[0036] <Cyclic Azine Compounds>

[0037] The cyclic azine compound according to one embodiment of the present disclosure is represented by formula (1):

[0038] [Chemistry 4]

[0039]

[0040] In formula (1),

[0041] Ar 1 is phenyl or 4-biphenyl;

[0042] Ar 2 is a group represented by any one of formulas (2-1) to (2-3);

[0043] [Chemistry 5]

[0044]

[0045] Ar 3 is a group represented by formula (3);

[0046] [Chemistry 6]

[0047]

[0048] In formula (3), Ar 31 represents a hydrogen atom or a group represented by any one of formulae (2-1) to (2-3).

[0049] Hereinafter, the cyclic azine compound represented by the formula (1) may be referred to as a cyclic azine compound (1). The definitions and preferred specific examples of the substituents in the cyclic azine compound (1) are as follows.

[0050] [Ar 2 ]

[0051] Ar 2 It is a group represented by any one of formulae (2-1) to (2-3).

[0052] [Chemistry 7]

[0053]

[0054] Considering the excellent driving voltage characteristics and current efficiency characteristics, Ar 2 More preferably, it is a group represented by formula (2-1), (2-2a), (2-2b), (2-3a) or (2-3b).

[0055] [Chemistry 8]

[0056]

[0057] [About Ar 3 ]

[0058] Ar 3 is a group represented by formula (3);

[0059] [Chemistry 9]

[0060]

[0061] Ar 31 represents a hydrogen atom or a group represented by any one of formulae (2-1) to (2-3).

[0062] Considering the excellent driving voltage characteristics and current efficiency characteristics, Ar 3 Preferred is a group represented by any one of formulae (3-1) to (3-9).

[0063] [Chemistry 10]

[0064]

[0065] When the cyclic azine compound (1) is used as a part of the constituent components of an organic light emitting diode (OLED), effects such as increased current efficiency and lowered driving voltage can be obtained. These effects are further exhibited when the cyclic azine compound (1) is used as an electron transport layer.

[0066] [Preferred examples of the cyclic azine compound (1)]

[0067] From the viewpoint of having both excellent driving voltage characteristics and excellent current efficiency characteristics, a cyclic azine compound represented by any one of the compounds (1-1) to (1-90) shown in Tables 1 to 3 is more preferred.

[0068] [Table 1]

[0069]

[0070] [Table 2]

[0071]

[0072] [Table 3]

[0073]

[0074] Among the cyclic azine compounds shown in Tables 1 to 3, cyclic azine compounds represented by formula (1-6), formula (1-15), formula (1-48), formula (1-49), formula (1-51), formula (1-52), formula (1-54), formula (1-64), formula (1-65), formula (1-66), formula (1-67), formula (1-71), formula (1-73) or formula (1-82) are preferred, especially from the perspective of having both excellent driving voltage characteristics and current efficiency characteristics of the element.

[0075] [Chemistry 11]

[0076]

[0077] Next, the use of the cyclic azine compound (1) will be described.

[0078] <Materials for organic electroluminescent elements, electron transport materials for organic electroluminescent elements>

[0079] The cyclic azine compound (1) is not particularly limited, and can be used, for example, as a material for an organic electroluminescent device. In addition, the cyclic azine compound (1) can be used, for example, as an electron transport material for an organic electroluminescent device.

[0080] That is, an organic electroluminescent element material according to one embodiment of the present disclosure contains a cyclic azine compound (1). In addition, an organic electroluminescent element electron transport material according to one embodiment of the present disclosure contains a cyclic azine compound (1). An organic electroluminescent element material and an organic electroluminescent element electron transport material containing a cyclic azine compound (1) contribute to the production of an organic electroluminescent element having both excellent driving voltage characteristics and current efficiency characteristics.

[0081] <Organic electroluminescent element>

[0082] An organic electroluminescent device according to one embodiment of the present disclosure includes a cyclic azine compound (1).

[0083] The structure of the organic electroluminescent element is not particularly limited, and examples thereof include the structures (i) to (vii) shown below.

[0084] (i): anode / light-emitting layer / cathode

[0085] (ii): anode / hole transport layer / light-emitting layer / cathode

[0086] (iii): anode / light-emitting layer / electron transport layer / cathode

[0087] (iv): anode / hole transport layer / light-emitting layer / electron transport layer / cathode

[0088] (v): anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode

[0089] (vi): anode / hole injection layer / charge generation layer / hole transport layer / light-emitting layer / electron transport layer / cathode

[0090] (vii): anode / hole injection layer / hole transport layer / electron blocking layer / luminescent layer / hole blocking layer / electron transport layer / electron injection layer / cathode

[0091] Below, taking the above-mentioned structure (vi) as an example, refer to Figure 1 The organic electroluminescent element according to one embodiment of the present disclosure will be described in more detail. Figure 1 This is a schematic cross-sectional view showing an example of a layered structure of an organic electroluminescent element including a cyclic azine compound according to one embodiment of the present disclosure.

[0092] It should be noted that Figure 1 The organic electroluminescent element shown has a so-called bottom emission type element structure, but the organic electroluminescent element of one embodiment of the present disclosure is not limited to the bottom emission type element structure. That is, the organic electroluminescent element of one embodiment of the present disclosure may be a top emission type element structure or other known element structures.

[0093] The organic electroluminescent element 100 sequentially comprises a substrate 1, an anode 2, a hole injection layer 3, a charge generation layer 4, a hole transport layer 5, a light emitting layer 6, an electron transport layer 7, and a cathode 8. However, some of these layers may be omitted, and conversely, other layers may be added. For example, an electron injection layer may be provided between the electron transport layer 7 and the cathode 8, or the charge generation layer 4 may be omitted and the hole transport layer 5 may be provided directly on the hole injection layer 3.

[0094] In addition, a structure having a single layer having the functions of two or more layers, such as an electron injection / transport layer having both the functions of an electron injection layer and an electron transport layer, may be used instead of the two or more layers. Furthermore, for example, a single-layer hole transport layer 5 and a single-layer electron transport layer 7 may each be composed of two or more layers.

[0095] [Layer containing the cyclic azine compound represented by formula (1)]

[0096] The organic electroluminescent element contains a cyclic azine compound represented by the above formula (1) in one or more layers selected from the group consisting of a light-emitting layer and a layer between the light-emitting layer and a cathode. Figure 1In the structural example shown, the organic electroluminescent element 100 contains the cyclic azine compound (1) in at least one layer selected from the group consisting of the light-emitting layer 6 and the electron transport layer 7. In particular, it is preferred that the electron transport layer 7 contains the cyclic azine compound (1).

[0097] The cyclic azine compound (1) may be contained in two or more layers of the organic electroluminescent device. When an electron injection layer is provided between the electron transport layer and the cathode, the electron injection layer may also contain the cyclic azine compound (1).

[0098] Hereinafter, an organic electroluminescent device 100 in which the electron transport layer 7 includes the cyclic azine compound (1) will be described.

[0099] [Substrate 1]

[0100] The substrate is not particularly limited, and examples thereof include a glass plate, a quartz plate, a plastic plate, etc. In the case of a structure in which light emission is extracted from the substrate 1 side, the substrate 1 is transparent with respect to the wavelength of light.

[0101] Examples of light-transmitting plastic films include films made of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like.

[0102] [Anode 2]

[0103] An anode 2 is provided on the substrate 1 (on the hole injection layer 3 side).

[0104] In the case of an organic electroluminescent element having a structure in which light emission is extracted through an anode, the anode is formed of a material that allows the light emission to pass through or substantially pass through.

[0105] There are no particular limitations on the transparent material used for the anode, and examples thereof include indium-tin oxide (ITO; Indium Tin Oxide), indium-zinc oxide (IZO: Indium Zinc Oxide), tin oxide, aluminum-doped tin oxide, magnesium-indium oxide, nickel-tungsten oxide, other metal oxides, metal nitrides such as gallium nitride, metal selenides such as zinc selenide, and metal sulfides such as zinc sulfide.

[0106] It should be noted that, in the case of an organic electroluminescent element having a structure in which light is extracted only from the cathode side, the transmission characteristics of the anode are not important. Therefore, examples of materials used for the anode in this case include gold, iridium, molybdenum, palladium, platinum, and the like.

[0107] A buffer layer (electrode interface layer) may also be provided on the anode.

[0108] [Hole injection layer 3, hole transport layer 5]

[0109] Between the anode 2 and the light-emitting layer 6 described later, a hole injection layer 3 , a charge generation layer 4 described later, and a hole transport layer 5 are provided in this order from the anode 2 side.

[0110] The hole injection layer and the hole transport layer have the function of transferring holes injected from the anode to the light-emitting layer. By interposing the hole injection layer and the hole transport layer between the anode and the light-emitting layer, a large number of holes can be injected into the light-emitting layer in a lower electric field.

[0111] In addition, the hole injection layer and the hole transport layer also function as electron barrier layers. That is, the electrons injected from the cathode and transported from the electron injection layer and / or the electron transport layer to the hole injection layer and / or the hole transport layer leak to the hole injection layer and / or the hole transport layer. The barrier of the electrons at the interface between the light-emitting layer and the hole injection layer and / or the hole transport layer is suppressed. As a result, the electrons are accumulated at the interface in the light-emitting layer, bringing about the effects of improving current efficiency, and an organic electroluminescent element with excellent luminescent performance can be obtained.

[0112] The material of the hole injection layer and the hole transport layer has at least one of hole injection property, hole transport property and electron barrier property. The material of the hole injection layer and the hole transport layer may be any of organic and inorganic substances.

[0113] Specific examples of materials for the hole injection layer and the hole transport layer include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline copolymers, conductive high molecular oligomers (especially thiophene oligomers), porphyrin compounds, aromatic tertiary amine compounds, styrylamine compounds, etc. Among them, porphyrin compounds, aromatic tertiary amine compounds, and styrylamine compounds are preferred, and aromatic tertiary amine compounds are particularly preferred.

[0114] Specific examples of the aromatic tertiary amine compound and the styrylamine compound include N,N,N',N'-tetraphenyl-4,4'-diaminophenyl, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-〔1,1'-biphenyl〕-4,4'-diamine (TPD), 2,2-bis(4-di-p-tolylaminophenyl)propane, 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane, N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl, 1,1-bis(4-di-p-tolylaminophenyl)-4-phenylcyclohexane, bis(4-dimethylamino-2-methylphenyl)phenylmethane, bis(4-di-p-tolylaminophenyl)phenylmethane, N,N'-diphenyl- N,N'-bis(4-methoxyphenyl)-4,4'-diaminobiphenyl, N,N,N',N'-tetraphenyl-4,4'-diaminodiphenyl ether, 4,4'-bis(diphenylamino)tetraphenyl, N,N,N-tri(p-tolyl)amine, 4-(di-p-tolylamino)-4'-〔4-(di-p-tolylamino)phenylvinyl〕stilbene, 4-N,N-diphenylamino-(2-diphenylvinyl)benzene, 3-methoxy-4'-N,N-diphenylaminostilbene, N-phenylcarbazole, 4,4'-bis〔N-(1-naphthyl)-N-phenylamino〕biphenyl (NPD), 4,4',4"-tri〔N-(3-methylphenyl)-N-phenylamino〕triphenylamine (MTDATA), etc.

[0115] Inorganic compounds such as p-type-Si and p-type-SiC can also be cited as examples of the material of the hole injection layer and the material of the hole transport layer.

[0116] The hole injection layer and the hole transport layer may have a single layer structure composed of one or two or more materials, or may have a laminated structure composed of two or more layers of the same composition or different compositions.

[0117] [Charge Generation Layer 4]

[0118] The charge generation layer 4 may be provided between the hole injection layer 3 and the hole transport layer 5 .

[0119] The material of the charge generating layer is not particularly limited, and examples thereof include dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN).

[0120] The charge generating layer may have a single layer structure composed of one or two or more materials, or may have a stacked structure composed of two or more layers of the same composition or different compositions.

[0121] [Luminous layer 6]

[0122] The light-emitting layer 6 is provided between the hole transport layer 5 and the electron transport layer 7 described later.

[0123] Examples of the material of the light-emitting layer include phosphorescent materials, fluorescent materials, and thermally activated delayed fluorescent materials. In the light-emitting layer, electron-hole pairs recombine, resulting in emission of light.

[0124] The light-emitting layer can be composed of a single low-molecular material or a single polymer material, or more generally, a host material doped with a guest compound. The light emission is mainly generated by the dopant and can have any color.

[0125] Examples of the host material include compounds having biphenyl, fluorenyl, triphenylsilyl, carbazole, pyrenyl, and anthracene groups. More specifically, DPVBi (4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl), BCzVBi (4,4'-bis(9-ethyl-3-carbazole vinyl)-1,1'-biphenyl), TBADN (2-tert-butyl-9,10-di(2-naphthyl)anthracene), ADN (9,10-di(2-naphthyl)anthracene), CBP (4,4'-bis(carbazole-9-yl)biphenyl), CDBP (4,4'-bis(carbazole-9-yl)-2,2'-dimethylbiphenyl), 2-(9-phenylcarbazole-3-yl)-9-[4-(4-phenylphenylquinazolin-2-yl)carbazole, and 9,10-bis(biphenyl)anthracene.

[0126] Examples of fluorescent dopants include anthracene, pyrene, tetracene, xanthene, perylene, rubrene, coumarin, rhodamine, quinacridone, dicyanomethylenepyran compounds, thiopyran compounds, polymethine compounds, pyrylium, thiopyranium compounds, fluorene derivatives, diindenoperylene derivatives, indenoperylene derivatives, bis(azinyl)amine boron compounds, bis(azinyl)methane compounds, quinolone compounds, etc. The fluorescent dopant may be a substance obtained by combining two or more selected from these.

[0127] Examples of the phosphorescent dopant include metal complexes such as iridium complexes, platinum complexes, palladium complexes, and osmium complexes.

[0128] Specific examples of fluorescent dopants and phosphorescent dopants include Alq3 (tris(8-hydroxyquinoline)aluminum), DPAVBi (4,4'-bis[4-(di-p-tolylamino)phenylvinyl]biphenyl), perylene, bis[2-(4-n-hexylphenyl)quinoline](acetylacetonate)iridium(III), Ir(PPy)3 (tris(2-phenylpyridine)iridium(III)), and FIrPic (bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III))).

[0129] The thermally activated delayed fluorescent luminescent material can be used as any of the above-mentioned host materials or guest materials. In addition, the thermally activated delayed fluorescent luminescent material itself does not emit light, but can also effectively transfer excitation energy to the fluorescent dopant that forms the luminescent layer simultaneously with the thermally activated delayed fluorescent luminescent material.

[0130] Specific examples of thermally activated delayed fluorescence include 4Cz-IPN (2,4,5,6-tetrakis(9-carbazolyl)-isophthalonitrile), 5Cz-BN (2,3,4,5,6-penta(9-carbazolyl)-benzonitrile), and DACTII (2-[3,6-bis(diphenylamino)carbazol-9-ylphenyl]-4,6-diphenyl-1,3,5-triazine).

[0131] In addition, the light-emitting material is not limited to being contained only in the light-emitting layer. For example, the layer adjacent to the light-emitting layer (hole transport layer 5 or electron transport layer 7) may also contain the light-emitting material. In this way, the current efficiency of the organic electroluminescent element can be further improved.

[0132] The light-emitting layer may have a single-layer structure composed of one or two or more materials, or may have a stacked structure composed of two or more layers of the same composition or different compositions.

[0133] [Electron transport layer 7]

[0134] An electron transport layer 7 is provided between the light emitting layer 6 and a cathode 8 described later.

[0135] The electron transport layer has the function of transferring electrons injected from the cathode to the light-emitting layer. By placing the electron transport layer between the cathode and the light-emitting layer, electrons can be injected into the light-emitting layer at a lower electric field.

[0136] As described above, the electron transport layer preferably contains the cyclic azine compound represented by the above formula (1).

[0137] In addition to the cyclic azine compound (1), the electron transport layer may contain a conventionally known electron transport material. Examples of conventionally known electron transport materials include 8-hydroxyquinoline lithium (Liq), bis(8-hydroxyquinoline) zinc, bis(8-hydroxyquinoline) copper, bis(8-hydroxyquinoline) manganese, tris(8-hydroxyquinoline) aluminum, tris(2-methyl-8-hydroxyquinoline) aluminum, tris(8-hydroxyquinoline) gallium, bis(10-hydroxybenzo[h]quinoline) beryllium, bis(10-hydroxybenzo[h]quinoline) zinc, bis(2-methyl-8-hydroxyquinoline) gallium chloride, bis(2-methyl-8-hydroxyquinoline)(o-cresol) gallium, bis(2-methyl-8-hydroxyquinoline)-1-naphthoate aluminum, or bis(2-methyl-8-hydroxyquinoline) gallium. )-2-naphthoate gallium, 2-[3-(9-phenanthrenyl)-5-(3-pyridyl)phenyl]-4,6-diphenyl-1,3,5-triazine, and 2-(4,"-di-2-pyridyl[1,1':3',1"-terphenyl]-5-yl)-4,6-diphenyl-1,3,5-triazine, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), BAlq (bis(2-methyl-8-hydroxyquinolinolato)-4-(phenylphenoxy)aluminum), and bis(10-hydroxybenzo[h]quinolinolato)beryllium), etc.

[0138] The electron transport layer may have a single layer structure composed of one or two or more materials, or may have a stacked structure composed of two or more layers of the same composition or different compositions.

[0139] When the electron transport layer has a two-layer structure in which the light-emitting layer side is a first electron transport layer and the cathode side is a second electron transport layer, the second electron transport layer preferably contains a cyclic azine compound (1).

[0140] [Cathode 8]

[0141] A cathode 8 is provided on the electron transport layer 7 .

[0142] In the case of an organic electroluminescent element having a structure in which only light emitted through an anode is extracted, the cathode may be formed of any conductive material.

[0143] Examples of materials for the cathode include sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixtures, magnesium / silver mixtures, magnesium / aluminum mixtures, magnesium / indium mixtures, aluminum / aluminum oxide (Al2O3) mixtures, indium, lithium / aluminum mixtures, and rare earth metals.

[0144] A buffer layer (electrode interface layer) may be provided on the cathode (on the electron transport layer side).

[0145] [Method for forming each layer]

[0146] Each layer other than the electrodes (anode, cathode) described above can be formed by thin-filming the material of each layer (together with a material such as a binder resin and a solvent as necessary) using a known method such as vacuum deposition, spin coating, casting, and LB (Langmuir-Blodgett method).

[0147] The film thickness of each layer formed in this way is not particularly limited and can be appropriately selected depending on the situation, but is usually in the range of 5 nm to 5 μm.

[0148] The anode and cathode can be formed by thinning the electrode material by evaporation or sputtering. During evaporation or sputtering, a pattern can be formed by a mask of a desired shape, or a pattern of a desired shape can be formed by photolithography after a thin film is formed by evaporation or sputtering.

[0149] The thickness of the anode and the cathode is preferably 1 μm or less, more preferably 10 nm or more and 200 nm or less.

[0150] The organic electroluminescent element of one mode of the present disclosure can be used as a lamp such as a light source for lighting or exposure, and can also be used as a projection device for projecting images, a display device (display) for directly visually confirming still images or dynamic images. When used as a display device for reproducing moving images, the driving method can be a simple matrix (passive matrix) method or an active matrix method. In addition, by using two or more organic electroluminescent elements of this mode with different luminescent colors, a full-color display device can be produced.

[0151] In addition, the cyclic azine compound (1) of one embodiment of the present disclosure can be synthesized by appropriately combining known reactions (for example, Suzuki-Miyaura cross-coupling reaction, etc.).

[0152] For example, the cyclic azine compound (1) according to one embodiment of the present disclosure can be synthesized according to the production method shown in any one of the following reaction formulas (a) to (f), but the invention is not to be construed as being limited to these examples.

[0153] [Chemistry 12]

[0154] Reaction (a)

[0155]

[0156] [Chemistry 13]

[0157] Reaction (b)

[0158]

[0159] [Chemistry 14]

[0160] Reaction (c)

[0161]

[0162] [Chemistry 15]

[0163] Reaction (d)

[0164]

[0165] [Chemistry 16]

[0166] Reaction (e)

[0167]

[0168] [Chemistry 17]

[0169] Reaction (f)

[0170]

[0171] In reaction formulas (a) to (f), Ar 1 ,Ar 2 and Ar 3 It is the same definition as that of formula (1).

[0172] X 2 and X 3 Respectively independently represent leaving groups. As leaving groups, there is no particular limitation, for example, chlorine atom, bromine atom, iodine atom, trifluoromethanesulfonyloxy etc. can be cited. Wherein, from the aspect of good reaction yield, preferably bromine atom or chlorine atom. However, from the availability of raw materials, it is sometimes preferred to use trifluoromethanesulfonyloxy.

[0173] Y 2 and Y 3 Each independently represents ZnR as a metal-containing group 1 MgR 2 , or Sn(R 3 )3; or B(OR 4 )2; where R 1 and R 2 Each independently represents a chlorine atom, a bromine atom or an iodine atom; R 3 represents an alkyl group or a phenyl group having 1 to 4 carbon atoms; R 4 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group; B(OR 4 )2 of 2 R 4 can be the same or different. 4 The oxygen atom and the boron atom may be integrated to form a ring.

[0174] As ZnR 1 MgR 2 , examples include ZnCl, ZnBr, ZnI, MgCl, MgBr, MgI, and the like.

[0175] As Sn(R 3 )3, examples include Sn(Me)3, Sn(Bu)3, etc.

[0176] As B(OR 4 )2, examples include B(OH)2, B(OMe)2, B(O i Pr)2, B(OBu)2, etc. In addition, as two R 4 When B(OR 4 The examples of )2 are not particularly limited, and the following groups (I) to (VI) can be exemplified. From the viewpoint of good yield, the group represented by (II) is preferred.

[0177] [Chemistry 18]

[0178]

[0179] The methods shown in reaction formulas (a) to (d) are described in more detail by taking the method shown in reaction formula (a) as an example. The method shown in reaction formula (a) indicates that: in the presence of a palladium catalyst, Y 2 -Ar 2 and Y 3 -Ar 3 The cyclic azine compound (1) is obtained by sequentially using the reaction. 2 -Ar 2 and Y 3 -Ar 3 Can be used at the same time to react, in addition, use Y 2 -Ar 2 The intermediate product obtained by the reaction is separated once, and then, in the presence of a palladium catalyst, Y 3 -Ar 3 Alternatively, by first reacting Y 3 -Ar 3 By using it for the reaction, a cyclic azine compound (1) can also be obtained.

[0180] The methods shown in reaction formulas (e) and (f) are described below by taking the method shown in reaction formula (e) as an example. The method shown in reaction formula (e) represents the step of reacting X 3 -Ar 3The cyclic azine compound (1) is obtained by reaction. In addition, the cyclic azine compound as a raw material used in the production methods shown in reaction formulas (e) and (f) can be produced according to International Publication No. 2017 / 025164, for example. In addition, commercially available products can also be used.

[0181] Among the production methods represented by reaction formulae (a) to (f), the production method represented by reaction formulae (e) or (f) is preferred because the purity of the obtained cyclic azine compound (1) is high.

[0182] [Method for producing cyclic azine compound]

[0183] A production method according to one embodiment of the present disclosure is a method for producing a cyclic azine compound represented by formula (1), comprising the step of reacting a compound represented by formula (4) with a compound represented by formula (5):

[0184] [Chemistry 19]

[0185] Reaction formula (g)

[0186]

[0187] In the formula,

[0188] Ar 1 is phenyl or 4-biphenyl;

[0189] Ar 2 is a group represented by any one of formulas (2-1) to (2-3);

[0190] [Chemistry 20]

[0191]

[0192] Ar 3 is a group represented by formula (3);

[0193] [Chemistry 21]

[0194]

[0195] Ar 31 represents a hydrogen atom, or a group represented by any one of formulae (2-1) to (2-3);

[0196] X 4 is the leaving group;

[0197] Y 4 is a halogen atom, a metal-containing group, or a boron-containing group.

[0198] Here, the leaving group in formula (4) has the same definition as the leaving group in the above reaction formulas (a) to (f). In addition, the metal-containing group or boron-containing group in formula (5) has the same definition as the leaving group in the above reaction formulas (a) to (f).

[0199] According to the present aspect described above, it is possible to provide a method for producing a cyclic azine compound capable of producing a cyclic azine compound having both excellent driving voltage characteristics and excellent current efficiency characteristics.

[0200] [Pyridine compounds]

[0201] The pyridine compound according to one embodiment of the present disclosure is a pyridine compound represented by formula (5):

[0202] [Chemistry 22]

[0203]

[0204] In the formula, Ar 2 is a group represented by any one of formulas (2-1) to (2-3);

[0205] [Chemistry 23]

[0206]

[0207] Ar 3 is a group represented by formula (3);

[0208] [Chemistry 24]

[0209]

[0210] Ar 31 represents a hydrogen atom, or a group represented by any one of formulae (2-1) to (2-3);

[0211] Y 4 is a halogen atom, a metal-containing group, or a boron-containing group.

[0212] Here, the metal-containing group or boron-containing group in formula (5) has the same definition as the leaving group in the above reaction formulas (a) to (f).

[0213] The pyridine compound represented by formula (5) is preferably a pyridine compound represented by formula (5-1), (5-2) or (5-3):

[0214] [Chemistry 25]

[0215]

[0216] In the formula,

[0217] Ar 2and Y 4 Same as formula (5);

[0218] Ar 31 Synonymous with formula (3).

[0219] According to the present aspect described above, it is possible to provide a pyridine compound that contributes to the production of a cyclic azine compound having both excellent driving voltage characteristics and excellent current efficiency characteristics.

[0220] Example

[0221] Hereinafter, the present disclosure will be described in further detail based on Examples, but the present disclosure is not to be construed as being limited to these Examples.

[0222] 1 The H-NMR spectrum was measured using Gemini 200 (manufactured by Varian) or Bruker ASCEND 400 (400 MHz; manufactured by Bruker).

[0223] The light emission characteristics of the organic electroluminescent element were evaluated by applying a direct current to the produced element at room temperature using a luminance meter (product name: BM-9, manufactured by TOPCON TECHNOHOUSE CORPORATION).

[0224] Synthesis Example-1

[0225] [Chemistry 26]

[0226]

[0227] Under argon atmosphere, 2-(4-biphenyl)-4-phenyl-6-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-biphenyl-3-yl]-1,3,5-triazine (2.60 g, 4.4 mmol), 6-(2-biphenyl)-3-chloropyridine (1.25 g, 4.9 mmol), 2M-potassium phosphate aqueous solution (6.6 mL), palladium acetate (30 mg, 0.13 mmol) and 2-dicyclohexylphosphino-2',6'-diisopropoxybiphenyl (RuPhos, 124 mg, 0.27 mmol) were suspended in diethylene glycol dimethyl ether (diglyme, 40 mL) and stirred at 150°C for 27 hours. After cooling, water was added to the reaction mixture, and the solid was filtered and washed with water and methanol. The obtained solid was dissolved in hot toluene, and activated carbon was added to filter through diatomaceous earth. The resulting solution was cooled to room temperature, and the precipitated white solid was collected to obtain 2-(4-biphenylyl)-4-phenyl-6-{5-[6-(2-biphenylyl)-pyridin-3-yl]-biphenyl-3-yl}-1,3,5-triazine (1-6) (yield 2.62 g, yield 85%).

[0228] 1 H-NMR (400MHz, CDCl3): δ9.14 (dd, J=2.3, 0.7Hz, 1H), 9.01 (dd, J=1.8, 1.5Hz, 2H), 8.8 6(d,J=8.9Hz,2H),8.81(d,J=6.5Hz,2H),8.02(dd,J=1.8,1.5Hz,1H),7.84-7.86(m,2H ),7.83(d,J=8.6Hz,2H),7.80(d,J=8.4Hz,2H),7.72(d,J=7.1Hz,2H),7.46-7.65(m,11 H),7.43(t,J=7.3Hz,1H),7.28-7.33(m,4H),7.08-7.14(m,1H),7.06(d,J=8.1Hz,1H).

[0229] Synthesis Example-2

[0230] [Chemistry 27]

[0231]

[0232] Under argon atmosphere, 2M potassium phosphate aqueous solution (3.8 mL) was added to a solution of 2-(4-biphenyl)-4-phenyl-6-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)-1,1':4',1"-terphenyl-3-yl]-1,3,5-triazine, 2-(2-biphenyl)-5-chloropyridine (731 mg, 2.8 mmol), palladium acetate (17 mg, 0.075 mmol), and RuPhos (70 mg, 0.15 mmol) in diethylene glycol dimethyl ether (25 mL), and the mixture was stirred at 150°C for 3 hours. After cooling to room temperature, water was added to the reaction solution. , methanol to filter out the solid, and wash it with water and then with methanol. The obtained solid was dried under reduced pressure, dissolved in toluene (450 mL) under reflux, activated carbon (0.4 g) was added, the activated carbon was filtered from the suspension, and washed with hot toluene (150 mL). Toluene was distilled off from the filtrate, and the obtained solid was dried and solidified under reduced pressure, and then purified by recrystallization (xylene) to obtain 2-(4-biphenyl)-4-{5-[6-(2-biphenyl)pyridin-3-yl]-1,1':4',1"-terphenyl-3-yl}-6-phenyl-1,3,5-triazine (1-15) (1.66 g, 96%) as a white solid.

[0233] 1H-NMR(CDCl3): δ9.14(d,J=1.7Hz,1H),9.05(dd,J=1.5,1.5Hz,1H),9.00(dd,J=1.5,1.5Hz,1H),8.86(d,J=8.4 Hz,2H),8.81(dd,J=8.2,1.7Hz,2H),8.06(dd,J=1.5,1.5Hz,1H),7.88(d,J=8.4Hz,2H),7.79-7.83(m,2H),7.82 (d,J=8.2Hz,2H),7.79(d,J=8.2Hz,2H),7.72(d,J=7.3Hz,2H),7.70(d,J=7.3Hz,2H),7.59-7.63(m,3H),7.42- 7.59(m,7H),7.42(dd,J=7.3,7.3Hz,1H),7.40(dd,J=7.3,7.3Hz,1H),7.26-7.38(m,5H),7.06(d,J=8.2Hz,1H).

[0234] Synthesis Example-5

[0235] [Chemistry 28]

[0236]

[0237] Under an argon atmosphere, 2,4-bis(4-biphenylyl)-6-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-biphenyl-3-yl]-1,3,5-triazine (1.99 g, 3.0 mmol), 2-(2-biphenylyl)-3-chloropyridine (0.88 g, 3.3 mmol), palladium acetate (20 mg, 0.09 mmol) and a toluene solution of tricyclohexylphosphine (0.6 M, 0.3 mL, 0.18 mmol) were suspended in N,N-dimethylformamide (DMF, 30 mL). A 2M potassium phosphate aqueous solution (4.5 mL) was added to the suspension, and the mixture was heated under reflux for 22 hours. After cooling, water and methanol were added to the reaction mixture, and the precipitated solid was filtered out. The obtained solid was purified by recrystallization (toluene) to obtain the target 2,4-bis(4-biphenylyl)-6-{5-[2-(2-biphenylyl)pyridin-3-yl]-biphenyl-3-yl}-1,3,5-triazine (1-50) (1.74 g, 2.3 mmol, 76%).

[0238] 1H-NMR (CDCl3): δ8.78-8.82(m,6H),7.91(s,1H),7.90(dd,J=8.8,0.9Hz,1H),7.83(d,J=8.8Hz,4H),7.71-7.75(m,4H),7.52(dd,J=7.6Hz,4H),7. 37-7.48(m,9H),7.15(dd,J=7.6,0.9Hz,4H),6.99(t,J=3.5Hz,1H),6.94 (dt,J=7.3,1.3Hz,1H),6.87(t,J=7.4Hz,1H),6.55(dd,J=8.3,1.6Hz,2H)

[0239] Synthesis Example-6

[0240] [Chemistry 29]

[0241]

[0242] Under an argon atmosphere, 2M potassium phosphate aqueous solution (13.5 mL) was added to a solution of 2,4-bis(4-biphenylyl)-6-{5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)biphenyl-3-yl}-1,3,5-triazine (5.97 g, 9.0 mmol), 2-(2-biphenylyl)-5-chloropyridine (2.63 g, 9.9 mmol), palladium acetate (61 mg, 0.27 mmol), and RuPhos (252 mg, 0.54 mmol) in diethylene glycol dimethyl ether (90 mL), and the mixture was stirred at 150° C. for 3 hours. After cooling to room temperature, water and methanol were added to the reaction solution, and the solid was filtered out and washed with water and then methanol. The obtained solid was dried under reduced pressure, dissolved in toluene (500 mL) under reflux, activated carbon (2.0 g) was added, and the activated carbon was filtered from the suspension and washed with toluene (200 mL). The low boiling components were removed from the filtrate by distillation under reduced pressure, and then purified by recrystallization (xylene), thereby obtaining 2,4-bis(4-biphenylyl)-6-{5-[6-(2-biphenylyl)pyridin-3-yl]biphenyl-3-yl}-1,3,5-triazine (1-51) (4.76 g, 69%) as a white solid.

[0243] 1H-NMR(CDCl3): δ9.13(d,J=1.8Hz,1H),9.02(dd,J=1.6,1.6Hz,1H),9.00(dd,J=1.6,1.6Hz,1H),8.8 6(d,J=8.4Hz,4H),8.01(dd,J=1.6,1.6Hz,1H),7.88-7.80(m,2H),7.82(d,J=8.4Hz,4H),7.80(d,J=7 .2Hz,2H),7.72(d,J=7.2Hz,4H),7.56(dd,J=7.3,7.3Hz,2H),7.47-7.54(m,3H),7.51(dd,J=7.3,7.3 Hz,4H),7.47(d,J=7.5Hz,1H),7.42(dd,J=7.3,7.3Hz,2H),7.26-7.36(m,5H),7.05(d,J=8.1Hz,1H).

[0244] Synthesis Example-9

[0245] [Chemistry 30]

[0246]

[0247] Under argon atmosphere, 2,4-bis(4-biphenyl)-6-{5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,1':2',1"-terphenyl-3-yl}-1,3,5-triazine (2.22 g, 3.0 mmol), 4-chloro-3-phenylpyridine (853 mg, 4.5 mmol) and palladium acetate (14 mg, 0.06 mmol) were suspended in DMF (30 mL). To the suspension was added a toluene solution of tricyclohexylphosphine (0.6 M, 0.2 mL, 0.12 mM). mol) and 2M-potassium phosphate (4.5 mL), and stirred at 130°C overnight. After cooling to room temperature, water and methanol were added, and the precipitated solid was filtered out, washed with water and then with methanol, and low boiling components were removed by distillation under reduced pressure. The obtained solid was purified by column chromatography (hexane: chloroform = 3: 1) and then recrystallized from toluene to obtain the target 2,4-bis(4-biphenyl)-6-{5-(3-phenylpyridin-4-yl)-1,1':2',1"-terphenyl-3-yl}-1,3,5-triazine (1-65) (1.49 g, 64%).

[0248] 1H-NMR(CDCl3): δ8.69-8.71(m,5H),8.62(d,J=5.0Hz,1H),8.52(t,J=1.6Hz,1H),8.36(t,J=1.6Hz,1H),7.80 (d,J=8.5Hz,4H),7.72(dd,J=7.1,1.4Hz,4H),7.41-7.54(m,9H),7.21-7.39(m,12H),7.12(d,J=4.6Hz,1H).

[0249] Synthesis Example-10

[0250] [Chemistry 31]

[0251]

[0252] Under nitrogen atmosphere, 2,4-bis(4-biphenyl)-6-{5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1,1':2',1"-terphenyl-3-yl}-1,3,5-triazine (85 g, 115 mmol), 4-bromopyridine hydrochloride (33.5 g, 172 mmol) and tetrakis(triphenylphosphine)palladium (5.3 g, 4.6 mmol) were suspended in THF. (1.15L). To the suspension was added 2M potassium phosphate aqueous solution (345mL) and heated to reflux for 5 hours. After cooling, water and methanol were added and the precipitate was filtered. The filtrate was purified by recrystallization from toluene to obtain the target 2,4-bis(4-biphenyl)-6-{5-(4-pyridyl)-1,1':2',1"-terphenyl-3-yl}-1,3,5-triazine (1-64) (59.8g, 75%).

[0253] Synthesis Example-11

[0254] [Chemistry 32]

[0255]

[0256] Under an argon atmosphere, 2,4-bis(4-biphenyl)-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(4-pyridyl)phenyl]-1,3,5-triazine (3.00 g, 4.5 mmol), 1-bromo-4-phenylnaphthalene (1.66 g, 5.9 mmol) and tetrakis(triphenylphosphine)palladium (156 mg, 0.13 mmol) were suspended in THF (45 mL). 2M-potassium carbonate aqueous solution (6.7 mL) was added to the suspension and heated under reflux for 22 hours. After cooling, water and methanol were added to the reaction mixture, and the precipitated solid was filtered out. The obtained solid was purified by recrystallization (toluene) to obtain the target 2,4-bis(4-biphenylyl)-6-[3-(4-phenyl-naphthalen-1-yl)-5-(4-pyridyl)phenyl]-1,3,5-triazine (1-73) (2.67 g, 80%).

[0257] 1 H-NMR(CDCl3)δ9.17(t,J=1.6Hz,1H),9.05(t,J=1.6Hz,1H),8.87(dt,J=8.6,1.8Hz,4H),8.78(dd,J=4.6,1.6Hz,2H),8.04-8.07(m,3H),7.82(dt, J=8.6,1.8Hz,4H),7.77(dd,J=4.6,1.6Hz,2H),7.71(dt,J=7.0,2.0Hz,4H ),7.68(d,J=7.2Hz,1H),7.47-7.62(m,12H),7.42(tt,J=7.3,2.1Hz,2H).

[0258] Synthesis Example-12

[0259] [Chemistry 33]

[0260]

[0261] Under argon atmosphere, 2,4-bis(4-biphenyl)-6-[3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(4-pyridyl)phenyl]-1,3,5-triazine (3.50 g, 5.3 mmol), 6-phenyl-2-trifluoromethanesulfonyloxynaphthalene (2.41 g, 6.8 mmol), palladium acetate (60 mg, 0.27 mmol) and 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos, 252 mg, 0.53 mmol) were suspended in THF (55 mL). 2M-potassium carbonate aqueous solution (7.7 mL) was added to the suspension, and the mixture was heated under reflux for 15 hours. After cooling to room temperature, water and methanol were added to the reaction mixture, and the precipitated solid was filtered out. The obtained solid was purified by recrystallization (toluene) to obtain the target 2,4-bis(4-biphenylyl)-6-[3-(6-phenyl-naphthalen-2-yl)-5-(4-pyridyl)phenyl]-1,3,5-triazine (1-92) (3.21 g, 4.3 mmol, 83%).

[0262] 1 H-NMR(CDCl3): δ9.22(t,1.5Hz,1H),9.08(t,1.5Hz,1H),8.91(d,J=8.4Hz,4H),8 .81(dd,J=3.1,1.5Hz,2H),8.29(s,1H),8.23(t,J=1.5Hz,1H),8.15(s,1H),8.10 (t,J=8.3Hz,2H),7.98(dt,J=8.9,1.7Hz,1H),7.86(dt,J=8.3,1.9Hz,4H),7.78( t,J=6.3Hz,4H),7.73(dd,J=8.4,1.4Hz,4H)7.56-7.50(m,7H),7.46-7.41(m,3H).

[0263] Synthesis Example-13

[0264] [Chemistry 34]

[0265]

[0266] Under nitrogen atmosphere, 3-bromo-5-chlorobiphenyl (50 g, 186.9 mmol), 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)-2-phenylpyridine (63 g, 224.3 mmol), and tetrakis(triphenylphosphine)palladium (4.3 g, 3.7 mmol) were suspended in THF (370 mL) at 60°C. 4M-potassium phosphate (140 mL) was added to the suspension, and the mixture was heated under reflux for 10 hours. After cooling to room temperature, toluene was added to the reaction mixture, and the organic layer was extracted. Magnesium sulfate and activated carbon were added to the organic layer, and the insoluble components were filtered out. After the filtrate was concentrated, it was purified by recrystallization from ethanol to obtain the target 3-chloro-5-(2-phenylpyridin-3-yl)biphenyl (5-1) (45.5 g, 71%).

[0267] 1 H-NMR(CDCl3): δ8.73(dd,4.8,1.7Hz,1H),7.79(dd,tt,1.7Hz,1H),7.46(t,1.8Hz, 1H),7.42-7.30(m,9H),7.27(d,1.8Hz,1H),7.25-7.24(m,2H),7.18(t,1.6Hz,1H).

[0268] Under nitrogen atmosphere, compound 5-1 (197.8 g, 578.7 mmol), bispinacolatodiboron (154.3 g, 607.7 mmol) and potassium acetate (170.4 g, 1736 mmol) were suspended in THF (1.16 L) at 60°C. Palladium acetate (1.3 g, 5.8 mmol) and a THF solution (30 mL) of 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos, 5.5 mg, 11.6 mmol) were added to the suspension and heated under reflux for 6 hours. After cooling to room temperature, activated carbon was added to the reaction mixture and stirred, and the insoluble components were filtered out. The filtrate was concentrated and purified by recrystallization from hexane to obtain the target 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(2-phenylpyridin-3-yl)biphenyl (5-2) (178 g, 71%).

[0269] 1 H-NMR(CDCl3): δ8.70(dd,4.8,1.7Hz,1H),7.92(dd,1.8,1.0Hz,1H),7.86(dd,7.7,1.7Hz,1H),7 .79(dd,1.8,1.0Hz,1H),7.41-7.38(m,2H),7.36-7.27(m,8H),7.23-7.21(m,2H),1.36(s,12H).

[0270] Synthesis Example-14

[0271] [Chemistry 35]

[0272]

[0273] Under nitrogen atmosphere, 2-chloro-4,6-di(4-biphenyl)triazine (176.2 g, 420 mmol), compound 5-2 (200 g, 462 mmol) and tetrakis(triphenylphosphine)palladium (4.9 g, 4.2 mmol) were suspended in THF (4.2 L). A 2M-potassium phosphate aqueous solution (0.6 L) was added to the suspension and heated under reflux for 6 hours. After cooling to room temperature, methanol was added and the precipitate was filtered. The filtrate and activated carbon were suspended in toluene at 80 degrees and the insoluble components were filtered out. After concentrating the filtrate, it was purified by recrystallization from toluene to obtain the target 4,6-di(4-biphenyl)-2-[5-(2-phenylpyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (1-48) (182 g, 63%).

[0274] 1 H-NMR(CDCl3): δ9.02(t,1.6Jz,1H),8.90(d,8.6Hz,4H),8.80(t,1.6Hz,1H),8.77(dd,4.7,1.7Hz,1H),8.09(dd,7.7, 1.7Hz,1H),7.93(d,8.6Hz,4H),7.82(d,8.2Hz,4H),7.77(t,1.8Hz,1H),7.62-7.32(m,16H),7.29(tt,7.3,1.4Hz,1H).

[0275] Synthesis Example-15

[0276] [Chemistry 36]

[0277]

[0278] Under argon atmosphere, 4,6-bis(4-biphenylyl)-2-{3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)biphenyl-5-yl}-1,3,5-triazine (3.0 g, 4.52 mmol), 2-chloro-3-phenylpyridine (943 mg, 4.97 mmol), palladium acetate (51 mg, 0.23 mmol), 2-dicyclohexylphosphino-2',6'-diisopropoxybiphenyl (202 mg, 0.45 mmol) were suspended in THF (46 mL). 2.0 M potassium phosphate aqueous solution (7 mL) was added to the suspension, and the mixture was heated under reflux for 24 hours. After cooling, water and methanol were added to the reaction mixture. The generated solid was collected by filtration and washed with hexane to obtain the target 4,6-bis(4-biphenylyl)-2-{5-(3-phenyl-pyridin-2-yl)biphenyl-3-yl}-1,3,5-triazine (1-54) (2.92 g, 4.23 mmol, 94%).

[0279] 1 H-NMR(CDCl3)δ7.36-7.55(m,17H),7.01-7.75(m,4H),7.80-7.88(m,6H),8 .79-8.84(m,5H),8.87(dd,J=1.6,1.5Hz,1H),8.93(dd,J=1.7,1.6Hz,1H).

[0280] In addition, the cyclic azine compounds represented by formula (1-49), (1-52), (1-66), (1-67) and (1-71) were synthesized by the same method as the production method shown in Synthesis Examples-1 to 15.

[0281] The structural formulas and abbreviations of compounds used in the preparation and performance evaluation of organic electroluminescent devices containing the cyclic azine compound (1) as a constituent component are shown below.

[0282] [Chemistry 37]

[0283]

[0284] Element Example-1 (refer to Figure 2 )

[0285] (Preparation of substrate 101 and anode 102)

[0286] As a substrate having an anode on its surface, a glass substrate with an ITO transparent electrode having a 2 mm wide indium tin oxide (ITO) film (thickness 110 nm) patterned into stripes was prepared. Next, the substrate was cleaned with isopropyl alcohol and then surface treated by ozone ultraviolet cleaning.

[0287] (Preparation for vacuum deposition)

[0288] On the cleaned and surface-treated substrate, each layer is vacuum-deposited by vacuum deposition to form each layer in a stacked manner.

[0289] First, the glass substrate was introduced into a vacuum deposition tank and the pressure was reduced to 1.0×10 -4 Pa. Then, the following procedures were followed to prepare the films according to the film forming conditions of each layer.

[0290] (Fabrication of Hole Injection Layer 103)

[0291] The sublimation purified HTL and NDP-9 were deposited into a film of 10 nm at a rate of 0.15 nm / sec to form the hole injection layer 103 .

[0292] (Fabrication of the First Hole Transport Layer 1051)

[0293] The HTL purified by sublimation was formed into a film with a thickness of 85 nm at a rate of 0.15 nm / sec to prepare the first hole transport layer 1051 .

[0294] (Fabrication of Second Hole Transport Layer 1052)

[0295] The sublimated and purified EBL-3 was deposited into a film with a thickness of 5 nm at a rate of 0.15 nm / sec to form the second hole transport layer 1052 .

[0296] (Fabrication of Light Emitting Layer 106)

[0297] BH-1 and BD-2 purified by sublimation were formed into a 20 nm film at a ratio of 95:5 (mass ratio) to form the light emitting layer 106. The film formation rate was 0.18 nm / sec.

[0298] (Fabrication of First Electron Transport Layer 1071)

[0299] The HBL-1 purified by sublimation was deposited into a film with a thickness of 6 nm at a rate of 0.05 nm / sec to form the first electron transport layer 1071 .

[0300] (Fabrication of Second Electron Transport Layer 1072)

[0301] Compound 1-48 and Liq were deposited into a 25 nm film at a ratio of 50:50 (mass ratio) to form the second electron transport layer 1072. The film deposition rate was 0.15 nm / sec.

[0302] (Manufacturing of cathode 108)

[0303] Finally, a metal mask was arranged to be orthogonal to the ITO stripes on the substrate to form a cathode 108. As for the cathode, silver / magnesium (mass ratio 1 / 10) and silver were formed into films of 80 nm and 20 nm in this order, respectively, to form a two-layer structure. The film formation rate of silver / magnesium was 0.5 nm / sec, and the film formation rate of silver was 0.2 nm / sec.

[0304] Thus, the Figure 2 The light emitting area shown is 4mm 2 The organic electroluminescent element 100. The film thicknesses of the respective films were measured by a stylus film thickness meter (DEKTAK, manufactured by Bruker).

[0305] Furthermore, the device was sealed in a nitrogen atmosphere glove box with an oxygen and water concentration of 1 ppm or less. The sealing was performed on the glass sealing cap and the film-forming substrate (device) using bisphenol F epoxy resin (manufactured by Nagase ChemteX).

[0306] A direct current was applied to the organic electroluminescent element prepared as described above, and the light emission characteristics were evaluated using a brightness meter (product name: BM-9, manufactured by TOPCON TECHNOHOUSE CORPORATION). As the light emission characteristics, a current density of 10 mA / cm 2 The current efficiency (cd / A) at the time of driving voltage is shown in Table 4. It should be noted that the driving voltage is a relative value when the result in the element reference example 3 described later is taken as the reference value (100).

[0307] Component Comparison Example-1

[0308] The obtained measurement results are shown in Table 4. An organic electroluminescent device was prepared and evaluated in the same manner as in Device Example-1 except that ETL-1 was used instead of Compound 1-48.

[0309] Component Reference Example-1

[0310] The obtained measurement results are shown in Table 4. An organic electroluminescent device was prepared and evaluated in the same manner as in Device Example 1, except that ETL-2 described in Patent Document 1 was used instead of Compound 1-48.

[0311] Component Reference Example-2

[0312] The obtained measurement results are shown in Table 4. An organic electroluminescent device was prepared and evaluated in the same manner as in Device Example 1, except that ETL-3 described in Patent Document 1 was used instead of Compound 1-48.

[0313] Component Reference Example-3

[0314] In Element Example-1, an organic electroluminescent element was prepared and evaluated by the same method as Element Example-1, except that ETL-4 described in Japanese Patent Laid-Open No. 2017-105717 was used instead of Compound 1-48. The obtained measurement results are shown in Table 4.

[0315] [Table 4]

[0316] Compound Driving voltage Current efficiency Component Example-1 1-48 98 104 Component Comparison Example-1 ETL-1 100 89 Component Reference Example-1 ETL-2 100 95 Component Reference Example-2 ETL-3 103 96 Component Reference Example-3 ETL-4 100 100

[0317] Element Example-2 (refer to Figure 3 )

[0318] (Preparation of substrate 101 and anode 102)

[0319] As a substrate having an anode on its surface, a glass substrate with an ITO transparent electrode having a 2 mm wide indium tin oxide (ITO) film (thickness 110 nm) patterned into stripes was prepared. Next, the substrate was cleaned with isopropyl alcohol and then surface treated by ozone ultraviolet cleaning.

[0320] (Preparation for vacuum deposition)

[0321] On the cleaned and surface-treated substrate, each layer is vacuum-deposited by vacuum deposition to form each layer in a stacked manner.

[0322] First, the glass substrate was introduced into a vacuum deposition tank and the pressure was reduced to 1.0×10 -4 Pa. Then, the following procedures were followed to prepare the films according to the film forming conditions of each layer.

[0323] (Fabrication of Hole Injection Layer 103)

[0324] The HIL purified by sublimation was deposited into a film of 50 nm at a rate of 0.15 nm / sec to form the hole injection layer 103 .

[0325] (Fabrication of Charge Generation Layer 104)

[0326] The HAT-CN purified by sublimation was formed into a film with a thickness of 5 nm at a rate of 0.15 nm / sec to form the charge generation layer 104 .

[0327] (Fabrication of the First Hole Transport Layer 1051)

[0328] The HTL purified by sublimation was deposited into a film with a thickness of 10 nm at a rate of 0.15 nm / sec to form the first hole transport layer 1051 .

[0329] (Fabrication of Second Hole Transport Layer 1052)

[0330] The sublimated and purified EBL-2 was deposited into a film with a thickness of 5 nm at a rate of 0.15 nm / sec to form the second hole transport layer 1052 .

[0331] (Fabrication of Light Emitting Layer 106)

[0332] BH-2 and BD-1 purified by sublimation were formed into a 25 nm film at a ratio of 95:5 (mass ratio) to form the light emitting layer 106. The film formation rate was 0.18 nm / sec.

[0333] (Fabrication of First Electron Transport Layer 1071)

[0334] The HBL-2 ​​purified by sublimation was deposited into a film with a thickness of 5 nm at a rate of 0.05 nm / sec to form the first electron transport layer 1071 .

[0335] (Fabrication of Second Electron Transport Layer 1072)

[0336] Compound 1-48 and Liq were deposited into a 25 nm film at a ratio of 50:50 (mass ratio) to form the second electron transport layer 1072. The film deposition rate was 0.15 nm / sec.

[0337] (Manufacturing of cathode 108)

[0338] Finally, a metal mask was arranged to be orthogonal to the ITO stripes on the substrate to form a cathode 108. As for the cathode, silver / magnesium (mass ratio 1 / 10) and silver were formed into films of 80 nm and 20 nm in this order, respectively, to form a two-layer structure. The film formation rate of silver / magnesium was 0.5 nm / sec, and the film formation rate of silver was 0.2 nm / sec.

[0339] Thus, the Figure 3 The light emitting area shown is 4mm 2 The organic electroluminescent element 100. The film thicknesses of the respective films were measured by a stylus film thickness meter (DEKTAK, manufactured by Bruker).

[0340] Furthermore, the device was sealed in a nitrogen atmosphere glove box with an oxygen and water concentration of 1 ppm or less. The sealing was performed on the glass sealing cap and the film-forming substrate (device) using bisphenol F epoxy resin (manufactured by Nagase ChemteX).

[0341] A direct current was applied to the organic electroluminescent element prepared as described above, and the light emission characteristics were evaluated using a brightness meter (product name: BM-9, manufactured by TOPCON TECHNOHOUSE CORPORATION). As the light emission characteristics, a current density of 10 mA / cm 2The current efficiency (cd / A) at the time of driving voltage is shown in Table 5. It should be noted that the driving voltage is a relative value when the result in the element reference example 4 described later is taken as the reference value (100).

[0342] Component Example-3

[0343] The obtained measurement results are shown in Table 5. In Element Example-2, an organic electroluminescent element was prepared and evaluated by the same method as in Element Example-2, except that Compound 1-49 was used instead of Compound 1-48.

[0344] Component Example-4

[0345] An organic electroluminescent device was prepared and evaluated in the same manner as in Device Example 2, except that Compound 1-50 synthesized in Synthesis Example 5 was used instead of Compound 1-48.

[0346] Component Example-5

[0347] An organic electroluminescent device was prepared and evaluated in the same manner as in Device Example 2, except that Compound 1-51 synthesized in Synthesis Example 6 was used instead of Compound 1-48.

[0348] Component Example-6

[0349] The obtained measurement results are shown in Table 5. In Element Example-2, an organic electroluminescent element was prepared and evaluated by the same method as in Element Example-2, except that Compound 1-52 was used instead of Compound 1-48.

[0350] Component Example-7

[0351] The obtained measurement results are shown in Table 5. In Element Example-2, an organic electroluminescent element was prepared and evaluated by the same method as in Element Example-2, except that Compound 1-64 was used instead of Compound 1-48.

[0352] Component Example-8

[0353] The obtained measurement results are shown in Table 5. In Element Example-2, an organic electroluminescent element was prepared and evaluated by the same method as in Element Example-2, except that Compound 1-65 was used instead of Compound 1-48.

[0354] Component Reference Example-4

[0355] In Element Example-2, an organic electroluminescent element was prepared and evaluated by the same method as Element Example-2, except that ETL-4 described in Japanese Patent Laid-Open No. 2017-105717 was used instead of Compound 1-48. The obtained measurement results are shown in Table 5.

[0356] [Table 5]

[0357] Compound Driving voltage Current efficiency Component Example-2 1-48 98 110 Component Example-3 1-49 99 115 Component Example-4 1-50 97 101 Component Example-5 1-51 97 106 Component Example-6 1-52 96 104 Component Example-7 1-64 97 109 Component Example-8 1-65 97 110 Component Reference Example-4 ETL-4 100 100

[0358] Component Example-9

[0359] In Element Example-1, EBL-4 was used instead of EBL-3, BD-3 was used instead of BD-2, and Compound 1-67 was used instead of Compound 1-48. As the cathode, ytterbium, silver / magnesium (mass ratio 9 / 1) and silver were formed into films of 2 nm, 12 nm and 90 nm in this order to form a three-layer structure. In addition, an organic electroluminescent element was prepared and evaluated in the same manner as Element Example-1. Here, the film formation rate of ytterbium was 0.02 nm / sec, the film formation rate of silver / magnesium was 0.5 nm / sec, and the film formation rate of silver was 0.2 nm / sec. The obtained measurement results are shown in Table 6.

[0360] Component Reference Example-5

[0361] The obtained measurement results are shown in Table 6. In Element Example-9, an organic electroluminescent element was prepared and evaluated by the same method as in Element Example-9, except that ETL-4 was used instead of Compound 1-67.

[0362] [Table 6]

[0363] Compound Driving voltage Current efficiency Component Example-9 1-67 98 104 Component Reference Example-5 ETL-4 100 100

[0364] Component Example-10

[0365] In Element Example-1, EBL-4 was used instead of EBL-3, BD-3 was used instead of BD-2, and as the cathode, ytterbium, silver / magnesium (mass ratio 9 / 1) and silver were formed into films of 2 nm, 12 nm and 90 nm in this order to form a three-layer structure. The same method as Element Example-1 was used to prepare an organic electroluminescent element and evaluate it. Here, the film formation speed of ytterbium was 0.02 nm / sec, the film formation speed of silver / magnesium was 0.5 nm / sec, and the film formation speed of silver was 0.2 nm / sec. The obtained measurement results are shown in Table 7.

[0366] Component Example-11

[0367] The obtained measurement results are shown in Table 7. In Element Example-10, an organic electroluminescent element was prepared and evaluated by the same method as in Element Example-10, except that Compound 1-66 was used instead of Compound 1-48.

[0368] Component Example-12

[0369] The obtained measurement results are shown in Table 7. In Element Example-10, an organic electroluminescent element was prepared and evaluated by the same method as in Element Example-10, except that Compound 1-62 was used instead of Compound 1-48.

[0370] Component Comparison Example-2

[0371] The obtained measurement results are shown in Table 7. An organic electroluminescent device was prepared and evaluated in the same manner as in Device Example 10, except that ETL-1 was used instead of Compound 1-48.

[0372] [Table 7]

[0373] Compound Driving voltage Current efficiency Component Example-10 1-48 97 105 Component Example-11 1-66 96 108 Component Example-12 1-62 97 108 Component Comparison Example-2 ETL-1 100 100

[0374] According to Tables 4 to 7, the cyclic azine compound (1) according to one embodiment of the present disclosure can provide an organic electroluminescent device having both excellent driving voltage characteristics and current efficiency characteristics compared to conventionally known cyclic azine compounds.

[0375] In addition, the cyclic azine compound (1) of one embodiment of the present disclosure is used as an electron transport material for an organic electroluminescent device having both excellent driving voltage characteristics and current efficiency characteristics. Furthermore, the cyclic azine compound (1) can provide an organic electroluminescent device with low power consumption.

[0376] In addition, a thin film composed of the cyclic azine compound (1) of one embodiment of the present disclosure is useful as a material for an organic electroluminescent element, and is useful as an electron transport material, a hole block material, a light-emitting host material, etc., because it is excellent in electron transport performance, hole block performance, redox resistance, water resistance, oxygen resistance, electron injection characteristics, etc. It is particularly useful when used as an electron transport material.

[0377] Furthermore, the cyclic azine compound (1) according to one embodiment of the present disclosure has a wide band gap and a high triplet excitation energy level, and therefore can be applied not only to conventional fluorescent devices but also to organic electroluminescent devices utilizing phosphorescent devices and thermally activated delayed fluorescence (TADF).

[0378] While the present invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the present invention.

[0379] It should be noted that the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2019-139746 filed on July 30, 2019 are cited herein and introduced as a disclosure of the specification of the present invention.

[0380] Explanation of symbols

[0381] 1,101 substrate

[0382] 2,102 Anode

[0383] 3,103 Hole injection layer

[0384] 4,104 Charge generation layer

[0385] 5,105 Hole transport layer

[0386] 6,106 light-emitting layer

[0387] 7,107 Electron transport layer

[0388] 8,108 cathode

[0389] 51,1051 First hole transport layer

[0390] 52,1052 Second hole transport layer

[0391] 71,1071 First electron transport layer

[0392] 72,1072 Second electron transport layer

[0393] 100 Organic electroluminescent elements

Claims

1. A cyclic azine compound represented by formula (1), wherein: In formula (1), Ar 1 is phenyl or 4-biphenyl; Ar 2 is a group represented by any one of formulas (2-1) to (2-3); Ar 3 A group represented by any one of the formulae (3-2), (3-3), (3-5) to (3-7), and (3-9); 2. The cyclic azine compound according to claim 1, wherein Ar 2 is a group represented by formula (2-1), (2-2a), (2-2b), (2-3a) or (2-3b), 3. The cyclic azine compound according to claim 1 or 2, wherein The cyclic azine compound is a cyclic azine compound represented by formula (1-6), (1-15), (1-48), (1-51), (1-52), (1-54), (1-65) or (1-66), 4 . A material for an organic electroluminescent device, comprising the cyclic azine compound according to claim 1 . 5 . An electron transport material for an organic electroluminescent device, comprising the cyclic azine compound according to claim 1 . 6 . An organic electroluminescent device comprising the cyclic azine compound according to claim 1 .

7. A method for producing a cyclic azine compound according to any one of claims 1 to 3, comprising reacting a compound represented by formula (4) with a compound represented by formula (5); Reaction formula (g) In the formula, Ar 1 is phenyl or 4-biphenyl; Ar 2 is a group represented by any one of formulas (2-1) to (2-3); Ar 3 A group represented by any one of the formulae (3-2), (3-3), (3-5) to (3-7), and (3-9); X 4 is the leaving group; Y 4 is a halogen atom, a metal-containing group, or a boron-containing group.

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