Pyrimidine compounds, as well as organic electroluminescent elements, electronic elements, and electronic devices using the same compounds.

Abstract

Provided is an organic electroluminescence (EL) device with improved light extraction efficiency compared to the prior art. [Solution] A capping layer containing a pyrimidine compound represented by the following general formula (I) is formed on an anode, a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode: TIFF2026169147000030.tif40170 In the formula, Ar 1 and Ar 2 each represent an aryl group or a heteroaryl group, and at least one of Ar 1 and Ar 2 represents a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a quinoxalinyl group, an imidazopyridyl group or an oxazolo[5,4-b]pyridyl group, Ar 3 represents a specific aryl group or heteroaryl group, L 1 and L 2 each represent a single bond or an unsubstituted arylene group or heteroarylene group, and any two of X 1 , X 2 and X 3 are nitrogen atoms, and the remaining one is a methine group.

Description

[Technical Field]

[0001] The present invention relates to pyrimidine compounds suitable for self-emitting electronic elements used in various display devices, particularly organic electroluminescent elements (hereinafter abbreviated as "organic EL elements"), and to organic EL elements, electronic elements, and electronic devices using the compound. [Background technology]

[0002] In recent years, light-emitting devices with a top-emission structure, which use a metal with a high work function as the anode and emit light from the top, have come into use. In bottom-emission light-emitting devices, which extract light from the bottom where the pixel circuit is located, the area of ​​the light-emitting part is limited. In contrast, top-emission light-emitting devices have the advantage that, because light is extracted from the top, it is not blocked by the pixel circuit, and a wide light-emitting area can be secured. On the other hand, in top-emission light-emitting devices, if the light emitted from the light-emitting layer is incident on another film at an angle greater than a certain angle, it is totally reflected at the interface between the light-emitting layer and the other film, and only a portion of the emitted light can be used. Therefore, in order to improve the light extraction efficiency, light-emitting devices have been proposed in which a capping layer with a high refractive index is provided on the outside of a translucent electrode (cathode) such as LiF / Al / Ag, Ca / Mg, or LiF / MgAg with a low refractive index (see Non-Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2014 / 009310 [Patent Document 2] International Publication No. 2013 / 179536 [Non-patent literature]

[0004] [Non-Patent Document 1] Appl.Phys.Lett., 2001, Volume 78, No. 4, p.544-546 [Non-Patent Document 2] Appl.Phys.Lett., 2003, Volume 82, Issue 3, p.466-468 [Non-Patent Document 3] Tetrahedron, 2002, Vol. 58, pp. 9633-9695 [Non-Patent Document 4] Appl.Phys.Lett., 2011, Volume 98, No. 8, Paper number 083302 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Conventionally, highly detailed metal masks have been used to form the capping layer. However, when used under high-temperature conditions, heat causes distortion in the metal mask, leading to a decrease in alignment accuracy. Therefore, ZnSe (melting point: 1100°C or higher), which is used for the capping layer in Non-Patent Literature 2, cannot be deposited in the correct position using a highly detailed metal mask, and this misalignment may adversely affect the light-emitting element. Furthermore, since film deposition by sputtering also adversely affects the light-emitting element, inorganic materials are not suitable as constituent materials for the capping layer.

[0006] Furthermore, Non-Patent Document 1 proposes using tris(8-hydroxyquinoline)aluminum (Alq3) as a constituent material for the capping layer to adjust the refractive index. However, Alq3 is a common material used as a green light-emitting material or electron transport material, and it exhibits weak absorption around 450 nm, which is close to the emission wavelength of blue light-emitting materials. Therefore, when Alq3 is used in a blue light-emitting device, there is a problem of reduced color purity and light extraction efficiency.

[0007] As described above, in order to improve the device characteristics and light extraction efficiency of organic EL elements, there is a need for a material that can be used in the capping layer, has a high refractive index, a low extinction coefficient, and excellent thin-film stability, deposition properties, and durability.

[0008] The object of the present invention is to provide a compound suitable for use as a capping layer in an organic EL element, which has a high refractive index in the wavelength range of 450 nm to 750 nm and a low extinction coefficient. Another object of the present invention is to provide an organic EL element with improved light extraction efficiency compared to conventional elements. [Means for solving the problem]

[0009] To achieve the above objectives, the inventors focused on the excellent stability and durability of pyrimidine compounds in thin films and diligently optimized the molecular design. As a result, they developed a material with a high refractive index and low extinction coefficient in the wavelength range of 450 nm to 750 nm, thereby completing the present invention. In other words, the present invention includes the following configuration.

[0010] 1) An organic electroluminescent element having an anode, a hole transport layer, a light-emitting layer, an electron transport layer, a cathode, and a capping layer in that order, wherein the capping layer contains a pyrimidine compound represented by the following general formula (I):

[0011] [ka]

[0012] Here, Ar 1 and Ar 2 Each of these independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, Ar 1 and Ar 2 At least one of these represents a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted imidazopyridyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, Ar 3represents a substituted phenyl group having only one cyano group as a substituent (unsubstituted cyanophenyl group), a substituted pyridyl group having only one cyano group as a substituent (unsubstituted cyanopyridyl group), an unsubstituted aryl group or an unsubstituted heteroaryl group, L 1 and L 2 each independently represent a single bond, or an unsubstituted arylene group or an unsubstituted heteroarylene group, X 1 , X 2 and X 3 each independently represent a nitrogen atom or an unsubstituted methine group (-CH=), and X 1 , X 2 and X 3 any two of them are nitrogen atoms, and the remaining one is a methine group.

[0013] 2) In the general formula (I), Ar 3 is the unsubstituted cyanophenyl group, unsubstituted cyanopyridyl group, unsubstituted phenyl group, unsubstituted naphthyl group, unsubstituted phenanthryl group, unsubstituted pyridyl group, unsubstituted quinolyl group, unsubstituted quinoxalinyl group or unsubstituted imidazopyridyl group, the organic electroluminescence device according to 1). 3) In the general formula (I), L 1 and L 2 each independently represent a single bond, or an unsubstituted phenylene group, unsubstituted naphthylene group, unsubstituted pyridinediyl group, unsubstituted pyrimidinediyl group, unsubstituted quinoxalinediyl group and unsubstituted oxazolopyridinediyl group, the organic electroluminescence device according to 1) or 2). 4) In the general formula (I), Ar 1 and Ar 2The organic electroluminescent element according to any one of 1) to 3), wherein each is independently a substituted pyridyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted imidazopyridyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group. 5) In the above general formula (I), Ar 1 However, it is a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted quinoxalinyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, and L 1 The organic electroluminescent element is one of the following, wherein the bond is a single bond, or an unsubstituted phenylene group or an unsubstituted biphenylene group. 6) An organic electroluminescent element according to any one of 1) to 5), wherein a film of the compound represented by the general formula (I) is deposited on a glass substrate to a thickness of 60 nm by vacuum deposition, and the refractive index measured at room temperature (25±2℃) using spectroscopic ellipsometry is 2.00 or greater in the wavelength range of 450 nm to 750 nm. 7) The organic electroluminescent element according to any one of 1) to 6), wherein the capping layer is a laminated or mixed layer containing two or more compounds including the pyrimidine compound represented by the general formula (I).

[0014] 8) An electronic element or electronic device having a pair of electrodes and at least one organic layer, wherein the organic layer contains a compound represented by the general formula (I).

[0015] 9) Pyrimidine compounds represented by the following general formula (II): [ka]

[0016] Here, Ar 1represents a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, and Ar 2 represents a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted quinoxalinyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, Ar 3 This represents a substituted phenyl group having only one cyano group as a substituent (unsubstituted cyanophenyl group), a substituted pyridyl group having only one cyano group as a substituent (unsubstituted cyanopyridyl group), an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted phenanthryl group, an unsubstituted pyridyl group, an unsubstituted quinolyl group, or an unsubstituted quinoxalinyl group. L 1 and L 2 Each of these independently represents a single bond or an unsubstituted arylene group. X 1 , X 2 and X 3 Each of these independently represents a nitrogen atom or an unsubstituted methine group (-CH=), and X 1 , X 2 and X 3 Two of them are nitrogen atoms, and the remaining one is a methine group.

[0017] 10) In the above general formula (II), L 1 and L 2 The pyrimidine compound described in 9), wherein each is independently a single bond, an unsubstituted phenylene group, an unsubstituted biphenylylene group, or an unsubstituted naphthylene group. 11) In the above general formula (II), Ar 1 is an unsubstituted oxazolo[5,4-b]pyridyl group, L 1 The pyrimidine compound according to 9) or 10), wherein is an unsubstituted phenylene group. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a compound that is suitable as a material for use in the capping layer of an organic EL element, having a high refractive index in the wavelength range of 450 nm to 750 nm and a low extinction coefficient. Furthermore, by providing a capping layer containing this compound on the outside of the electrodes of the organic EL element, the light extraction efficiency of the organic EL element can be improved compared to conventional methods. [Brief explanation of the drawing]

[0019] [Figure 1] This figure shows an example of the configuration of the organic EL element of the present invention. [Modes for carrying out the invention]

[0020] The embodiments of the present invention will be described in detail below. The following descriptions of the constituent elements may be based on representative embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples. In this specification, a numerical range represented by "~" means a range that includes the numbers written before and after "~" as the lower and upper limits. Furthermore, when a numerical range is described in steps, the upper and lower limits of each numerical range and the numbers described in the examples can be arbitrarily combined to create a new numerical range.

[0021] The isotopes of hydrogen atoms present in the molecule of the compound used in this invention are not particularly limited; for example, all hydrogen atoms in the molecule 1 H is fine, or part or all of it 2 It may also be H (deuterium D). In this specification, the term "substituted or unsubstituted" means that the group to which the term is attached may be an unsubstituted group (a group in which the hydrogen atoms are not substituted with substituents), or at least one hydrogen atom of the group to which the term is attached may be substituted with substituents.

[0022] In this specification, "organic layer" means a layer containing 70% by weight or more of an organic compound. "Transparent" means that the transmittance of visible light is 50% or more, and the transmittance of visible light is, for example, 80% or more, 90% or more, or 99% or more. The transmittance of visible light can be measured using an ultraviolet-visible spectrophotometer.

[0023] <Organic EL element> The organic EL element of the present invention comprises at least an anode, a hole transport layer, a light-emitting layer, an electron transport layer, a cathode, and a capping layer in this order.

[0024] Figure 1 is a schematic diagram showing the configuration of an organic EL element according to one embodiment of the present invention. As for the structure of the organic EL element, for example, in the case of a light-emitting element with a top emission structure, as shown in Figure 1, an anode 2, a hole transport layer 4, a light-emitting layer 5, an electron transport layer 6, a cathode 8, and a capping layer 9 are sequentially stacked on a glass substrate 1. Other examples include a hole injection layer 3 between the anode and the hole transport layer, an electron blocking layer (not shown) between the hole transport layer and the light-emitting layer, a hole blocking layer (not shown) between the light-emitting layer and the electron transport layer, and an electron injection layer 7 between the electron transport layer and the cathode. In these multilayer structures, one organic layer can perform multiple roles. That is, the organic EL element can have, for example, a configuration in which the hole injection layer and hole transport layer are combined, a configuration in which the hole transport layer and electron blocking layer are combined, a configuration in which the hole blocking layer and electron transport layer are combined, and / or a configuration in which the electron transport layer and electron injection layer are combined. Furthermore, an organic EL element may have a configuration in which two or more organic layers having the same function are stacked. Specifically, examples include a configuration with two stacked hole transport layers, a configuration with two stacked light-emitting layers, a configuration with two stacked electron transport layers, and a configuration with two stacked capping layers. The following describes each layer that constitutes the organic EL element.

[0025] [Capping layer] In the organic EL element of the present invention, the capping layer contains at least a pyrimidine compound represented by the general formula (I).

[0026] (Pyrimidine compounds represented by general formula (I)) In general formula (I), Ar 1 and Ar 2 Each of these independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. 3 This represents a substituted phenyl group having only one cyano group as a substituent (hereinafter also referred to as an "unsubstituted cyanophenyl group"), a substituted pyridyl group having only one cyano group as a substituent (hereinafter also referred to as an "unsubstituted cyanopyridyl group"), an unsubstituted aryl group, or an unsubstituted heteroaryl group.

[0027] Ar 1 and Ar 2 In the "substituted or unsubstituted aryl group" represented by Ar, the "aryl group" and Ar 3 The aromatic ring constituting the "aryl group" in the "unsubstituted aryl group" represented by may be a monoring, a fused ring formed by the fusion of two or more rings, a linked ring formed by the single bond between two or more rings, or a spiroring formed by the spiro bond between two or more rings. When the aromatic ring is a fused ring, the number of fused rings is, for example, 2 to 6, preferably 2 to 4. When the aromatic ring is a linked ring, the number of linked rings is, for example, 2 to 6, preferably 2 to 4. The number of carbon atoms constituting the aromatic ring is, for example, 6 to 30, 6 to 22, 6 to 18, 6 to 14, or 6 to 10. Specifically, the following groups can be cited as examples of the "aryl group" mentioned above: aryl groups having 6 to 30 carbon atoms, such as phenyl group, biphenylyl group, terphenylyl group, naphthyl group, anthryl group, phenanthryl group, indenyl group, pyrenyl group, perilenyl group, fluoranthenyl group, triphenylenyl group, fluorenyl group, and spirobifluorenyl group.

[0028] Ar 1 and Ar 2 In the "substituted or unsubstituted heteroaryl group" represented by , the "heteroaryl group" and Ar 3The aromatic heterocycle constituting the "heteroaryl group" in the "unsubstituted heteroaryl group" represented by may be a monocycle or a fused ring formed by the fusion of two or more rings. When the aromatic heterocycle is a fused ring, the number of fused rings is, for example, 2 to 6, preferably 2 to 4. Examples of heteroatoms constituting the aromatic heterocycle include nitrogen atoms, oxygen atoms, and sulfur atoms. The number of carbon atoms constituting the aromatic heterocycle is, for example, 2 to 40, 2 to 30, 2 to 18, or 2 to 12. Specifically, the following groups can be cited as examples of the "heteroaryl groups" mentioned above: heteroaryl groups having 2 to 40 carbon atoms, such as pyridyl group, pyrimidinyl group, triazinyl group, furyl group, pyrrolyl group, thienyl group, pyrazolyl group, quinolyl group, isoquinolyl group, quinoxalinyl group, quinazolyl group, naphthilidinyl group, benzofuranyl group, benzothienyl group, indolyl group, benzoxazolyl group, benzothiazolyl group, benzimidazolyl group, imidazopyridyl group, oxazolopyridyl group, oxazolopyradinyl group, dibenzofuranyl group, dibenzothienyl group, phenanthrolinyl group, acridinyl group, carbazolyl group, and carbolinyl group. The oxazolopyridyl group may be any of the following: oxazolo[4,5-b]pyridyl, oxazolo[5,4-b]pyridyl, oxazolo[4,5-c]pyridyl, or oxazolo[5,4-c]pyridyl. The phenanthrolinyl group may be any of the following: [4,7]phenanthrolinyl, [3,8]phenanthrolinyl, [2,9]phenanthrolinyl, or [1,10]phenanthrolinyl.

[0029] In general formula (I), L 1 and L 2Each of these independently represents a single-bonded or unsubstituted arylene group or an unsubstituted heteroarylene group. The aromatic ring constituting the "arylene group" in the "unsubstituted arylene group" may be a monoring, a fused ring formed by the fusion of two or more rings, a linked ring formed by the single bond of two or more rings, or a spiroring formed by the spiro bond of two or more rings. When the aromatic ring is a fused ring, the number of fused rings is, for example, 2 to 6, preferably 2 to 4. When the aromatic ring is a linked ring, the number of linked rings is, for example, 2 to 6, preferably 2 to 4. The number of carbon atoms constituting the aromatic ring is, for example, 6 to 30, 6 to 22, 6 to 18, 6 to 14, or 6 to 10. The "arylene group" in the "unsubstituted arylene group" is the above Ar 1 ~Ar 3 From the groups exemplified as "aryl groups" represented by , we can list groups obtained by removing one hydrogen atom from each, and specifically, the following groups can be listed: phenylene group, biphenylylene group, terphenylylene group, naphthylene group, anthrylene group, phenanthrylene group, indenylene group, pyrenylene group, peryleneylene group, fluorantheylene group, triphenylenylene group, fluorenylene group, and spirobifluorenylene group, which are arylene groups with 6 to 30 carbon atoms.

[0030] L 1 and L 2 The aromatic heterocycle constituting the "heteroarylene group" in the "unsubstituted heteroarylene group" represented by may be a monocycle or a fused ring formed by the fusion of two or more rings. When the aromatic heterocycle is a fused ring, the number of fused rings is, for example, 2 to 6, preferably 2 to 4. Examples of heteroatoms constituting the aromatic heterocycle include nitrogen atoms, oxygen atoms, and sulfur atoms. The number of carbon atoms constituting the aromatic heterocycle is, for example, 2 to 40, 2 to 30, or 2 to 18. The "heteroarylene group" in the "unsubstituted heteroarylene group" is the above Ar 1 ~Ar 3From the groups exemplified as "heteroaryl groups" represented by , we can list groups obtained by removing one hydrogen atom from each, and specifically, the following groups can be listed: heteroarylene groups with 2 to 40 carbon atoms, such as pyridinediyl group, pyrimidinediyl group, triazinediyl group, franzyl group, pyrrolediyl group, thiophenediyl group, pyrazolediyl group, quinolinediyl group, isoquinolinediyl group, quinoxalinediyl group, quinazolindiyl group, quinazolindiyl group, naphthyridinediyl group, benzofranzyl group, benzothiophenediyl group, indolediyl group, benzoxazolediyl group, benzothiazolediyl group, benzimidaldiyl group, imidazopyridinediyl group, oxazolopyridinediyl group, oxazolopyrazinediyl group, dibenzofranzyl group, dibenzothiophenediyl group, phenanthrolinediyl group, acridinediyl group, carbazolediyl group, and carbolinediyl group.

[0031] Ar 1 and Ar 2 The following atoms or groups can be specifically listed as "substituents" in the "substituted aryl group" and "substituted heteroaryl group" represented by the formula. Deuterium atoms; halogen atoms such as fluorine, chlorine, bromine, and iodine atoms; Cyano group; nitro group; silyl group such as trimethylsilyl group and triphenylsilyl group; Linear or branched alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, and propyl groups; Linear or branched alkyloxy groups with 1 to 6 carbon atoms, such as methoxy, ethoxy, and propoxy groups; Alkenyl groups such as vinyl groups and allyl groups; Aryl groups with 6 to 30 carbon atoms, such as phenyl, biphenylyl, terphenylyl, naphthyl, anthryl, phenanthryl, indenyl, pyrenyl, perilenyl, fluoranthenyl, triphenylenyl, fluorenyl, and spirobifluorenyl groups; Heteroaryl groups with 2 to 40 carbon atoms, such as pyridyl, pyrimidinyl, triazinyl, furyl, pyrrolyl, thienyl, pyrazolyl, quinolyl, isoquinolyl, quinoxalinyl, quinazolyl, naphthilidinyl, benzofuranyl, benzothienyl, indolyl, benzoxazolyl, benzothiazolyl, benzimidazolyl, imidazopyridyl, oxazolopyridyl, oxazolopyridyl, dibenzofuranyl, dibenzothienyl, phenanthrolinyl, acridinyl, carbazolyl, and carbolinyl groups; Aryloxy groups such as phenyloxy, tolyloxy, biphenylyloxy, and naphthyloxy; Aralkyloxy groups such as benzyloxy and phenethyloxy groups.

[0032] The hydrogen atoms in these substituents may be further substituted with the substituents exemplified above. Among the substituents exemplified above, atoms or groups selected from deuterium atoms, cyano groups, linear or branched alkyl groups having 1 to 6 carbon atoms, and aryl groups having 6 to 20 carbon atoms are preferred. Note that the substituents further substituted with the substituents are preferred for the parent skeleton (Ar 1 A substituent that directly substitutes for an aryl group or heteroaryl group (which is the parent skeleton) is sometimes referred to as the "first substituent," and a substituent that further substitutes for the first substituent is sometimes referred to as the "second substituent." Here, if the first substituent includes an aromatic ring, the aromatic ring may be bonded to the parent skeleton to form a cyclic structure. Also, if two or more second substituents substitute for the aromatic ring in the first substituent, adjacent second substituents may be bonded to each other to form a cyclic structure. Here, the bond between the aromatic ring in the first substituent and the parent skeleton, and the bond between the second substituents, may be a single bond or a bond via a linking group. Examples of linking groups include substituted or unsubstituted methylene groups, oxygen atoms, or sulfur atoms.

[0033] In general formula (I), Ar 1 and Ar 2At least one of these represents a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted imidazopyridyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group. 1 and Ar 2 Preferably, at least one of the groups is a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinoxalinyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, and more preferably an unsubstituted oxazolo[5,4-b]pyridyl group.

[0034] In a substituted pyrimidinyl group, the substituent on the pyrimidinyl group is preferably selected from the group consisting of a cyano group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, and an unsubstituted phenanthryl group, quinolyl group, and phenanthrolinyl group, among those exemplified above. More preferably, it is selected from the group consisting of a cyano group, an unsubstituted cyanophenyl group (i.e., a substituted phenyl group having only one cyano group as a substituent), an unsubstituted cyanonaphthyl group (i.e., a substituted naphthyl group having only one cyano group as a substituent), an unsubstituted naphthyl group, and an unsubstituted quinolyl group. Even more preferably, it is a cyano group, an unsubstituted cyanophenyl group, an unsubstituted cyanonaphthyl group, or an unsubstituted naphthyl group. The naphthyl group is preferably a 2-naphthyl group. That is, Ar 1 and / or Ar 2If is a substituted pyrimidinyl group, the substituted pyrimidinyl group is preferably a cyanopyrimidinyl group, a phenylpyrimidinyl group, a cyanophenylpyrimidinyl group, a naphthylpyrimidinyl group, a cyanonaphthylpyrimidinyl group, a phenanthrylpyrimidinyl group, a quinolylpyrimidinyl group, or a phenanthrolinylpyrimidinyl group; more preferably a cyanopyrimidinyl group, a cyanophenylpyrimidinyl group, a naphthylpyrimidinyl group, a cyanonaphthylpyrimidinyl group, or a quinolylpyrimidinyl group; and even more preferably a cyanopyrimidinyl group, a cyanophenylpyrimidinyl group, a naphthylpyrimidinyl group, or a cyanonaphthylpyrimidinyl group.

[0035] In a substituted pyridyl group, the substituents on the pyridyl group are preferably a cyano group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group, among the examples given above, with a cyano group or an unsubstituted naphthyl group being preferred. In a substituted quinoxalinyl group, the substituents on the quinoxalinyl group are preferably a cyano group, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group, among the examples given above, with a cyano group, an unsubstituted cyanophenyl group, an unsubstituted phenyl group, an unsubstituted cyanonaphthyl group, or an unsubstituted naphthyl group being more preferred, with a cyano group, an unsubstituted cyanophenyl group, an unsubstituted phenyl group, or an unsubstituted naphthyl group being even more preferred.

[0036] Ar 3 However, if the substituted phenyl group has only one cyano group as a substituent (a monosubstituted phenyl group), then this monosubstituted phenyl group can also be called an unsubstituted cyanophenyl group. Examples of cyanophenyl groups in an unsubstituted cyanophenyl group include 2-cyanophenyl, 3-cyanophenyl, or 4-cyanophenyl groups, but the 4-cyanophenyl group is preferred.

[0037] Ar 3However, if the substituted pyridyl group has only one cyano group as a substituent (a monosubstituted pyridyl group), then the monosubstituted pyridyl group can also be called an unsubstituted cyanopyridyl group. In an unsubstituted cyanopyridyl group, the cyanopyridyl group is preferably a 2-cyano-5-pyridyl group or a 3-cyano-6-pyridyl group, and more preferably a 2-cyano-5-pyridyl group.

[0038] Ar 1 and Ar 2 The substituted or unsubstituted aryl group or substituted or unsubstituted heteroaryl group represented by is preferably independently selected from the group consisting of substituted or unsubstituted phenyl group, naphthyl group, phenanthryl group, pyridyl group, pyrimidinyl group, quinolyl group, quinoxalinyl group, imidazopyridyl group and oxazolopyridyl group, more preferably selected from the group consisting of substituted pyridyl group and substituted or unsubstituted phenyl group, naphthyl group, pyrimidinyl group, quinolyl group, quinoxalinyl group, imidazopyridyl group and oxazolo[5,4-b]pyridyl group, and even more preferably an unsubstituted naphthyl group, an unsubstituted quinolyl group, an unsubstituted quinoxalinyl group, an unsubstituted imidazopyridyl group or an unsubstituted oxazolo[5,4-b]pyridyl group.

[0039] Ar 1 or Ar 2 Each group represented by and L 1 or L 2Examples of preferred configurations of the bond positions are shown below. In a substituted or unsubstituted naphthyl group (when the aryl group in a substituted or unsubstituted aryl group is a naphthyl group), the naphthyl group is preferably a 2-naphthyl group. In a substituted or unsubstituted phenanthryl group, the phenanthryl group is preferably a 9-phenanthryl group. In a substituted or unsubstituted pyridyl group, the pyridyl group is preferably a 3-pyridyl group or a 4-pyridyl group. In a substituted or unsubstituted pyrimidinyl group, the pyrimidinyl group is preferably a 2-pyridinyl group or a 4-pyridinyl group. In a substituted or unsubstituted quinolyl group, the quinolyl group is preferably a 2-quinolyl group, a 3-quinolyl group or a 6-quinolyl group. In a substituted or unsubstituted quinoxalinyl group, the quinoxalinyl group is preferably a 2-quinoxalinyl group or a 6-quinoxalinyl group. In substituted or unsubstituted imidazopyridyl groups, the imidazopyridyl group is preferably an imidazo[1,2-a]pyridyl group, and more preferably a 3-imidazo[1,2-a]pyridyl group. In substituted or unsubstituted oxazolopyridyl groups, the oxazolopyridyl group is preferably an oxazolo[5,4-b]pyridyl group, and more preferably a 2-oxazolo[5,4-b]pyridyl group or a 5-oxazolo[5,4-b]pyridyl group.

[0040] Ar 3 It is preferably selected from the group consisting of a substituted phenyl group having only one cyano group as a substituent (i.e., an unsubstituted cyanophenyl group), a substituted pyridyl group having only one cyano group as a substituent (i.e., an unsubstituted cyanopyridyl group), and an unsubstituted phenyl group, naphthyl group, phenanthryl group, pyridyl group, quinolyl group, quinoxalinyl group, and imidazopyridyl group, more preferably a substituted pyridyl group having only one cyano group as a substituent, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted quinolyl group, or an unsubstituted phenanthryl group, and even more preferably an unsubstituted phenyl group or an unsubstituted naphthyl group.

[0041] L 1 and L 2 Each of these groups is preferably independently selected from the group consisting of single-bonded and unsubstituted phenylene groups, biphenylylene groups, naphthylene groups, pyridinediyl groups, pyrimidinediyl groups, quinolinediyl groups, quinoxalindiyl groups, and oxazolopyridinediyl groups; more preferably selected from the group consisting of single-bonded and unsubstituted phenylene groups, naphthylene groups, pyridinediyl groups, pyrimidinediyl groups, quinoxalindiyl groups, and oxazolopyridinediyl groups; and even more preferably selected from the group consisting of single-bonded and unsubstituted phenylene groups, pyridinediyl groups, pyrimidinediyl groups, and quinoxalindiyl groups.

[0042] In an unsubstituted phenylene group (where the arylene group in an unsubstituted arylene group is a phenylene group), the phenylene group is preferably a 1,4-phenylene group. In an unsubstituted biphenylylene group, the biphenylylene group is preferably a 1,1'-biphenyl-4,4'-diyl group. In an unsubstituted naphthylene group, the naphthylene group is preferably a 2,6-naphthylene group. In an unsubstituted pyridinediyl group, the pyridinediyl group is preferably a pyridine-2,5-diyl group. In an unsubstituted pyrimidinediyl group, the pyrimidinediyl group is preferably a pyrimidine-2,5-diyl group. In an unsubstituted quinolinediyl group, the quinolinediyl group is preferably a 2,6-quinolinediyl group. In the unsubstituted quinoxalindiyl group, the quinoxalindiyl group is preferably a 2,6-quinoxalindiyl group. In the unsubstituted oxazolopyridinediyl group, the oxazolopyridinediyl group is preferably an oxazolo[5,4-b]pyridinediyl group, and more preferably an oxazolo[5,4-b]pyridine-2,5-diyl group.

[0043] In general formula (I), X 1 , X 2 and X 3 Each of these independently represents a nitrogen atom or an unsubstituted methine group (-CH=), and X1 , X 2 and X 3 any two of are nitrogen atoms, and the remaining one is an unsubstituted methine group. As the combination of the two nitrogen atoms, X 1 and X 2 , X 2 and X 3 and X 3 and X 1 may be any, but X 2 and X 3 or X 3 and X 1 are preferably nitrogen atoms.

[0044] In general formula (I), when Ar 1 is a group selected from the group consisting of a substituted pyridyl group, and a substituted or unsubstituted pyrimidinyl group, quinolyl group, quinoxalinyl group and oxazolo[5,4-b]pyridyl group, L 1 is preferably a single bond, an unsubstituted phenylene group or an unsubstituted biphenylene group, and further X 2 and X 3 or X 3 and X 1 are preferably nitrogen atoms.

[0045] (Pyrimidine compound represented by general formula (II)) Among the pyrimidine compounds represented by the aforementioned general formula (I) applied to the capping layer of the organic EL element of the present invention, the pyrimidine compound represented by the aforementioned general formula (II) is a novel compound and has a more characteristic structure. That is, the pyrimidine compound represented by the aforementioned general formula (I) may be the pyrimidine compound represented by the aforementioned general formula (II).

[0046] In general formula (II), Ar 1 represents a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, Ar 2 represents a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted quinoxalinyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, Ar3 This represents a substituted phenyl group having only one cyano group as a substituent (unsubstituted cyanophenyl group), a substituted pyridyl group having only one cyano group as a substituent (unsubstituted cyanopyridyl group), an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted phenanthryl group, an unsubstituted pyridyl group, an unsubstituted quinolyl group, or an unsubstituted quinoxalinyl group.

[0047] Ar 1 and Ar 2 The "substituted or unsubstituted oxazolo[5,4-b]pyridyl group" represented by Ar 2 Details regarding the "substituted pyridyl group," "substituted or unsubstituted pyrimidinyl group," "substituted or unsubstituted quinolyl group," and "substituted or unsubstituted quinoxalinyl group" represented by , and details regarding the "substituents" they may have, can be found in the explanation of general formula (I) above. Also, Ar 3 For further details regarding substituted phenyl groups (unsubstituted cyanophenyl groups) having only one cyano group as a substituent, and substituted pyridyl groups (unsubstituted cyanopyridyl groups) having only one cyano group as a substituent, please refer to the explanation in the above general formula (I) as appropriate.

[0048] In general formula (II), L 1 and L 2 Each of these independently represents a single bond or an unsubstituted arylene group. For details on the "arylene group" in "unsubstituted arylene group," refer to the explanation in general formula (I) above as appropriate.

[0049] Ar 1 The "substituted or unsubstituted oxazolo[5,4-b]pyridyl group" represented by is preferably an unsubstituted oxazolo[5,4-b]pyridyl group. 2 It is preferable that the group is selected from the group consisting of a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, and a substituted or unsubstituted oxazolo[5,4-b]pyridyl group. 3Preferably, this is a substituted phenyl group having only one cyano group as a substituent (i.e., an unsubstituted cyanophenyl group), an unsubstituted phenyl group, an unsubstituted naphthyl group, or an unsubstituted quinolyl group.

[0050] Ar 2 or Ar 3 Each group represented by and L 2 or pyrimidine ring (X 1 , X 2 and X 3 Examples of preferred configurations of the bond position between the carbon atom (including) and the oxy[5,4-b]pyridyl group are shown below. In substituted or unsubstituted pyridyl groups (including substituted pyridyl groups having only one cyano group as a substituent), the pyridyl group is preferably a 3-pyridyl group. In substituted or unsubstituted pyrimidinyl groups, the pyrimidinyl group is preferably a 2-pyridinyl group or a 4-pyridinyl group. In substituted or unsubstituted quinolyl groups, the quinolyl group is preferably a 2-quinolyl group, a 3-quinolyl group or a 6-quinolyl group. In substituted or unsubstituted quinoxalinyl groups, the quinoxalinyl group is preferably a 2-quinoxalinyl group. In substituted or unsubstituted oxazolo[5,4-b]pyridyl groups, the oxazolo[5,4-b]pyridyl group is preferably a 2-oxazolo[5,4-b]pyridyl group. In the case of an unsubstituted cyanophenyl group, it is preferable that the cyanophenyl group is a 4-cyanophenyl group. In the case of an unsubstituted naphthyl group, it is preferable that the naphthyl group is a 2-naphthyl group. In the case of an unsubstituted phenanthryl group, it is preferable that the phenanthryl group is a 9-phenanthryl group.

[0051] L 1 and L 2Each of these is preferably independently selected from the group consisting of single-bonded and unsubstituted phenylene groups, biphenylylene groups, and naphthylene groups, and more preferably a single-bonded or unsubstituted phenylene group. In the case of an unsubstituted phenylene group, the phenylene group is preferably a 1,4-phenylene group. In the case of an unsubstituted biphenylylene group, the biphenylylene group is preferably a 1,1'-biphenyl-4,4'-diyl group. In the case of an unsubstituted naphthylene group, the naphthylene group is preferably a 2,6-naphthylene group. As one of the preferred embodiments of general formula (II), Ar 1 is an unsubstituted oxazolo[5,4-b]pyridyl group, L 1 Examples of compounds in which the group is an unsubstituted phenylene group include those in which the group is unsubstituted.

[0052] In general formula (II), X 1 , X 2 and X 3 Each of these independently represents either a nitrogen atom or an unsubstituted methine group (-CH=). 1 , X 2 and X 3 Two of these are nitrogen atoms, and the remaining one is an unsubstituted methine group. The combination of two nitrogen atoms is X 1 and X 2 , X 2 and X 3 and X 3 and X 1 Either is fine, but X 2 and X 3 or X 3 and X 1 It is preferable that it is a nitrogen atom.

[0053] In general formulas (I) and (II), Ar 1 and Ar 2 These may be the same or different. Also, in general formulas (I) and (II), L 1 -Ar 1 and L 2 -Ar 2 It is preferable that at least one of the structures represented by contains two or more nitrogen atoms. Furthermore, L1 -Ar 1 and L 2 -Ar 2 It is more preferable that both structures represented by each contain two or more nitrogen atoms. Here, the nitrogen atoms include L 1 , L 2 Ar 1 , or Ar 2 This also includes nitrogen atoms contained in the cyano group as substituents that may be present. That is, as shown in the examples described later, in compounds (B-1) and (B-2) as comparative compounds, L 1 -Ar 1 or L 2 -Ar 2 The nitrogen atoms contained in the corresponding structure are one or zero. On the other hand, for example, the compound (1) according to the present invention used in Example 1 is L 1 -Ar 1 and L 2 -Ar 2 Both structures represented by these formulas have two nitrogen atoms. In other words, among the compounds represented by general formula (I) or (II), compounds that combine a pyrimidine ring with a high electron density with a structure having two or more nitrogen atoms are suggested to have a more pronounced effect in improving the light extraction efficiency when used in a capping layer.

[0054] The following are specific examples of compounds represented by general formula (I) and / or (II). However, the compounds represented by general formula (I) and / or (II) according to the present invention should not be interpreted restrictively by these specific examples. Also, in the chemical structural formulas below, hydrogen atoms ( 1 The notation H) has been omitted.

[0055] [ka]

[0056] [ka]

[0057]

change

[0058]

change

[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] The pyrimidine compounds represented by the general formula (I) or (II) can be synthesized, for example, by known coupling reactions using a palladium catalyst (see, for example, Non-Patent Document 3). Furthermore, the method for purifying the pyrimidine compounds is not particularly limited and can be purified by known methods used for purifying organic compounds, such as purification by column chromatography, adsorption purification using silica gel, activated carbon or activated clay, recrystallization or crystallization purification with a solvent, and sublimation purification. The compounds can be identified, for example, by NMR analysis.

[0076] For pyrimidine compounds, it is preferable to measure the melting point, glass transition temperature (Tg), sublimation temperature, refractive index, and extinction coefficient. The melting point and sublimation temperature serve as indicators of vapor deposition properties, while the glass transition temperature (Tg) is an indicator of the stability of the thin film state. Furthermore, the refractive index and extinction coefficient are indicators related to improving the efficiency of light extraction.

[0077] The melting point and glass transition temperature (Tg) of the powder can be measured using a high-sensitivity differential scanning calorimeter (e.g., Rigaku Holdings Corporation, product name: DSCvesta Thermó plus EV02 series). The refractive index and extinction coefficient can be measured using a spectroscopic ellipsometer (e.g., JAWoollam, model: M-2000U) for a film of pyrimidine compound deposited on a glass substrate to a thickness of 60 nm by vacuum deposition. Measurements are preferably performed at room temperature (25±2℃: i.e., in the range of 23~27℃).

[0078] In the present invention, the capping layer contains a pyrimidine compound represented by the general formula (I), but among the pyrimidine compounds represented by general formula (I), the pyrimidine compound represented by general formula (II) is more preferred. The capping layer may also be a laminated or mixed layer containing two or more compounds, including the pyrimidine compound represented by general formula (I) or (II). Examples of compounds other than the pyrimidine compound represented by general formula (I) or (II) include phthalic acid derivatives (see Patent Document 2). Of course, the capping layer may also contain two or more pyrimidine compounds represented by general formula (I) or (II).

[0079] The refractive index of the material constituting the capping layer is preferably greater than that of the material constituting the layer adjacent to the capping layer. That is, the capping layer improves the light extraction efficiency in an organic EL element, and this effect becomes more pronounced as the reflectivity at the interface between the capping layer and the layer in contact with the capping layer increases, because the effect of optical interference increases. Therefore, the refractive index of the material constituting the capping layer is preferably greater than that of the adjacent electrodes, and is preferably 1.70 or higher, more preferably 2.00 or higher, and even more preferably 2.10 or higher in the wavelength range of 450 nm to 750 nm. In this invention, the refractive index is expressed as the value obtained by rounding the corrected value, which is obtained by fitting the measured value by spectroscopic ellipsometry using analysis software (JAWoollam, product name: CompleteEASE) with a Cauchy model and then correcting it with a B-Spline model, to the third decimal place. For example, "refractive index of 1.70 or higher" means that the measured refractive index is 1.695 or higher.

[0080] [Other layers] The substrate is not particularly limited, and glass substrates, plastic substrates, etc., can be used. The substrate may be transparent or opaque. As the anode material, an electrode material with a large work function, such as ITO or gold, is used.

[0081] As materials for the hole injection layer, arylamine compounds having a structure in which two or more triphenylamine structures are linked in the molecule by single bonds or divalent groups that do not contain heteroatoms, such as starburst-type triphenylamine derivatives and various triphenylamine tetramers, porphyrin compounds represented by copper phthalocyanine, and acceptor-type heterocyclic compounds such as hexacyanoazatriphenylene, as well as coated polymer materials can be used.

[0082] As the material for the hole transport layer, benzidine derivatives such as N,N'-diphenyl-N,N'-di(m-tolyl)benzidine (TPD), N,N'-diphenyl-N,N'-di(α-naphthyl)benzidine, and N,N,N',N'-tetrabiphenylylbenzidine, as well as 1,1-bis[4-(di-4-tolylamino)phenyl]cyclohexane can be used. In particular, it is preferable to use an arylamine compound having a structure in which two triphenylamine structures are linked in the molecule by single bonds or by divalent groups that do not contain heteroatoms, such as N,N,N',N'-tetrabiphenylylbenzidine. It is also preferable to use an arylamine compound having a structure in which three or more triphenylamine structures are linked in the molecule by single bonds or by divalent groups that do not contain heteroatoms, such as various triphenylamine trimers and tetramers. Furthermore, coated polymer materials such as poly(3,4-ethylenedioxythiophene) / poly(styrene sulfonate) can be used as the material for the hole injection layer and the hole transport layer.

[0083] Furthermore, as materials for the hole injection layer and hole transport layer, materials that are P-doped with dopants such as trisbromophenylamine hexachloroantimony and radialene derivatives (see Patent Document 1) compared to materials normally used for these layers, as well as polymer compounds having a benzidine derivative structure such as TPD as a substructure, can be used.

[0084] The organic EL element of the present invention may have an electron blocking layer. As the material for the electron blocking layer, carbazole derivatives such as 4,4',4''-tri(N-carbazolyl)triphenylamine (TCTA), 9,9-bis[4-(carbazole-9-yl)phenyl]fluorene, 1,3-bis(carbazole-9-yl)benzene (mCP), and 2,2-bis(4-carbazole-9-yl-phenyl)adamantane, as well as compounds having an electron blocking effect, such as compounds having a triphenylsilyl group and a triarylamine structure, represented by 9-[4-(carbazole-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene, can be used.

[0085] As the material for the light-emitting layer, metal complexes of quinolinol derivatives such as Alq3, various metal complexes, anthracene derivatives, bis-styrylbenzene derivatives, pyrene derivatives, oxazole derivatives, and poly(p-phenylenevinylene) derivatives can be used. The light-emitting layer may also consist of a host material and a dopant material. Anthracene derivatives are preferably used as the host material. As the material for the light-emitting layer, heterocyclic compounds having an indole ring as a substructure of the fused ring, heterocyclic compounds having a carbazole ring as a substructure of the fused ring, carbazole derivatives, thiazole derivatives, benzimidazole derivatives, and polydialkylfluorene derivatives can be used as the host material. As the dopant material, quinacridone, coumarin, rubrene, perylene, pyrene and their derivatives, benzopyran derivatives, rhodamine derivatives, and aminostyryl derivatives can be used. As the dopant material, a green light-emitting material is preferably used.

[0086] Furthermore, phosphorescent materials can be used as dopant materials. As phosphorescent materials, metal complexes such as iridium and platinum can be used. Specifically, examples include green phosphorescent materials such as Ir(ppy)3, blue phosphorescent materials such as Firpic and Fir6, and red phosphorescent materials such as Btp2Ir(acac). Among these, the use of green phosphorescent materials is preferred. When using phosphorescent materials as dopant materials, hole-injecting and hole-transporting host materials such as 4,4'-di(N-carbazolyl)biphenyl, TCTA, and carbazole derivatives such as mCP, and electron-transporting host materials such as p-bis(triphenylsilyl)benzene and 2,2',2''-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) can be used.

[0087] To avoid concentration quenching, the doping of the phosphorescent material into the host material is preferably in the range of 1 to 30% by mass relative to the entire luminescent layer and is carried out by co-deposition.

[0088] Furthermore, materials that emit delayed fluorescence, such as PIC-TRZ, CC2TA, PXZ-TRZ, and CDCB derivatives like 4CzIPN, can also be used as dopant materials (see Non-Patent Literature 4).

[0089] The organic EL element of the present invention may have a hole-blocking layer. As the material for the hole-blocking layer, compounds having hole-blocking properties such as phenanthroline derivatives such as bathocuproine, metal complexes of quinolinol derivatives such as aluminum(III)bis(2-methyl-8-quinolinate)-4-phenylphenolate (BAlq), various rare earth complexes, triazole derivatives, triazine derivatives, pyrimidine derivatives, oxadiazole derivatives, and benzoazole derivatives can be used.

[0090] As materials for the electron transport layer, metal complexes of quinolinol derivatives such as Alq3 and BAlq, various metal complexes, triazole derivatives, triazine derivatives, pyrimidine derivatives, oxadiazole derivatives, pyridine derivatives, benzimidazole derivatives, benzoazole derivatives, thiadiazole derivatives, anthracene derivatives, carbodiimide derivatives, quinoxaline derivatives, pyridoindole derivatives, phenanthroline derivatives, and silole derivatives can be used.

[0091] As materials for the electron injection layer, alkali metal salts such as lithium fluoride and cesium fluoride, alkaline earth metal salts such as magnesium fluoride, metal complexes of quinolinol derivatives such as lithium quinolinol, metal oxides such as aluminum oxide, and metals such as ytterbium (Yb), samarium (Sm), calcium (Ca), strontium (Sr), and cesium (Cs) can be used. The electron injection layer can be omitted depending on the preferred selection of the electron transport layer and cathode.

[0092] Furthermore, as materials for the electron transport layer and electron injection layer, materials that are N-doped with metals such as cesium can be used in addition to the materials normally used for these layers.

[0093] Materials used for the cathode include metals with low work functions such as aluminum, alloys with even lower work functions such as magnesium-silver alloys, magnesium-calcium alloys, magnesium-indium alloys, and aluminum-magnesium alloys, as well as ITO and IZO.

[0094] In each of the layers constituting the organic EL element, various materials may be deposited individually, or they may be used as single layers deposited by mixing them with other materials. Alternatively, a laminated structure may be formed by depositing layers individually, layers deposited by mixing with other materials, or layers deposited individually and layers deposited by mixing with other materials. These materials can be deposited by known methods such as vapor deposition, spin coating, and inkjet. The total film thickness of each layer of the organic EL element is preferably 200 nm to 750 nm, and more preferably 350 nm to 600 nm. The film thickness of the capping layer is preferably, for example, 30 nm to 120 nm, and more preferably 40 nm to 80 nm. When the film thickness of the capping layer is within the above range, better light extraction efficiency can be obtained. The film thickness of the capping layer can be appropriately changed depending on the type of light-emitting material used in the light-emitting element and the film thickness of each layer other than the capping layer.

[0095] Furthermore, the organic EL element of the present invention is not limited to a top-emission structure, but can also be applied to organic EL elements having a bottom-emission structure or a dual-emission structure that emits light from both the top and bottom. In any case, the electrodes in the direction from which light is extracted from the light-emitting element are preferably transparent or semi-transparent.

[0096] The pyrimidine compounds of the present invention, represented by general formula (I) or (II), have the characteristics of a high refractive index, a low extinction coefficient, the ability to be deposited, a stable thin film state, and a high glass transition temperature. Therefore, by using such pyrimidine compounds in the capping layer, it is possible to provide an organic EL element that has high light extraction efficiency, suppresses the decrease in color purity, transmits light without change over time, and has a long lifespan.

[0097] <Electronic components or electronic devices> The electronic element or electronic device of the present invention comprises a pair of electrodes and at least one organic layer, wherein the organic layer contains a pyrimidine compound represented by the general formula (I) or (II). Preferably, at least one of the organic layers is provided on the outside of one of the electrodes, and more preferably, the organic layer provided on the outside of the electrode contains a pyrimidine compound represented by the general formula (I) or (II). [Examples]

[0098] The embodiments of the present invention will be described in detail below with reference to examples, but the present invention is not limited to the following embodiments unless it exceeds the gist of the invention.

[0099] The reagents used in the synthesis examples were manufactured by Tokyo Chemical Industry Co., Ltd., Sigma-Aldrich, or Alfa Aesar, among others. Furthermore, all reactions in the synthesis examples were carried out using reaction vessels equipped with condensers, stirrers, and thermometers. The identification of the compounds in the following synthesis examples was performed as follows: 1 H-NMR analysis (Bruker nuclear magnetic resonance spectrometer, model: Ascend) TM This was done using 400MHz.

[0100] [Synthesis Example 1: Synthesis of Compound (1)] In a reaction vessel, 3.3 g of fenchlorim, 10.4 g of 2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]oxazolo[5,4-b]pyridine (starting material 1), 6.1 g of potassium carbonate, 0.9 g of tetrakis(triphenylphosphine)palladium(0) (catalyst A), 88 mL of toluene, 22 mL of ethanol, and 44 mL of water were added, and the mixture was stirred under reflux for 6 hours. After confirming the completion of the reaction, the precipitate was filtered to obtain the crude product. The obtained crude product was dissolved in heated orthodichlorobenzene (ODB), activated clay was added, and the mixture was stirred for 30 minutes, followed by Celite filtration at 100°C. By adding n-hexane to the filtrate and filtering the resulting precipitate, compound (1) was obtained: 5.6 g (pale yellow powder, yield: 70%). In Synthesis Example 2 and subsequent examples, unless otherwise specified, after confirming the completion of the reaction, the precipitate was filtered off in the same manner as in Synthesis Example 1 to obtain the crude product. Furthermore, regarding the purification of the crude product, "purification in the same manner as in Synthesis Example 1" means that the crude product was purified using ODB in the same manner as in the present synthesis examples. However, n-hexane (acetone may be used instead) was added to the filtrate as needed, and the filtration temperature was adjusted as appropriate. 1 H-NMR (CDCl3): δ (ppm) = 8.78-7.84 (2H), 8.53-8.45 (8H), 8.42-8.40 (2H), 8.17 (1H), 8.15-8.12 (2H), 7.62-7.55 (3H), 7.42-7.39 (2H).

[0101] [Synthesis Example 2: Synthesis of Compound (7)] In a reaction vessel, 15.0 g of fenchlorim, 12.6 g of starting material 1, 19.3 g of potassium carbonate, 2.2 g of catalyst A, 150 mL of toluene, 38 mL of ethanol, and 75 mL of water were added, and the mixture was stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain 11.8 g of white powder A of 4-chloro-6-[4-(oxazolo[5,4-b]pyridine-2-yl)-phenyl]-2-phenylpyrimidine (yield: 66%).

[0102] Next, 5.0 g of the above-mentioned white powder A, 5.2 g of 3-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]quinoline (starting material 2), 3.6 g of potassium carbonate, 0.6 g of catalyst A, 50 mL of toluene, 13 mL of ethanol, and 25 mL of water were added to the reaction vessel and stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (7): 6.5 g (pale yellow powder, yield: 90%). 1 H-NMR(CDCl3): δ(ppm)=9.29-9.28(1H), 8.79-8.76(2H), 8.54-8.48(6H), 8.43-8.41(2 H), 8.19-8.12(3H), 7.96-7.93(3H), 7.79-7.75(1H), 7.65-7.54(4H), 7.42-7.39(1H).

[0103] [Synthesis Example 3: Synthesis of Compound (8)] In a reaction vessel, 5.00 g of white powder A, 5.2 g of 2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]quinoxaline, 3.6 g of potassium carbonate, 0.6 g of catalyst A, 50 mL of toluene, 13 mL of ethanol, and 25 mL of water were added, and the mixture was stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (8): 7.2 g (pale yellow powder, yield: 100%). 1 H-NMR(CDCl3): δ(ppm)=9.43(1H), 8.78-8.74(2H), 8.53-8.47(6H), 8.43-8.39(3H) , 8.23-8.20(1H), 8.17-8.11(3H), 7.85-7.77(2H), 7.61-7.54(3H), 7.41-7.38(1H).

[0104] [Synthesis Example 4: Synthesis of Compound (44)] 2,4-dichloro-6-phenylpyrimidine: 2.5 g, starting material 1: 7.9 g, potassium carbonate: 4.6 g, catalyst A: 0.5 g, toluene: 80 mL, ethanol: 20 mL, and water: 40 mL were added to a reaction vessel and stirred under reflux for 3 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (44): 6.9 g (pale yellow powder, yield: 89%). 1 H-NMR (CDCl3): δ(ppm)=8.94-8.92(2H), 8.51-8.47(6H), 8.42-8.39(2H), 8.36-8.33(2H), 8.15-8.11(3H), 7.64-7.57(3H), 7.42-7.38(2H).

[0105] [Synthesis Example 5: Synthesis of Compound (69)] 4.0 g of 2,4-dichloro-6-(naphthalene-2-yl)pyrimidine, 10.3 g of starting material 1, 6.0 g of potassium carbonate, 0.7 g of catalyst A, 80 mL of toluene, 20 mL of ethanol, and 40 mL of water were added to a reaction vessel and stirred under reflux for 4 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (69): 7.5 g (white powder, yield: 86%). 1 H-NMR (CDCl3): δ (ppm) = 8.96-8.94 (2H), 8.81 (1H), 8.55-8.39 (9H), 8.27 (1H), 8.14-8.04 (4H), 7.96-7.92 (1H), 7.61-7.57 (2H), 7.42-7.37 (2H).

[0106] [Synthesis Example 6: Synthesis of Compound (121)] In a reaction vessel, 3.0 g of fenchlorim, 9.7 g of 4,4,5,5-tetramethyl-2-(4-(quinoxaline-2-yl)phenyl)-1,3,2-dioxaborolane, 5.5 g of potassium carbonate, 0.8 g of catalyst A, 80 mL of toluene, 20 mL of ethanol, and 40 mL of water were added, and the mixture was stirred under reflux for 9 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (121): 6.1 g (pale yellow powder, yield: 81%). 1 H-NMR (CDCl3): δ (ppm) = 9.46 (2H), 8.80-8.79 (2H), 8.56-8.55 (4H), 8.46-8.45 (4H), 8.24-8.17 (5H), 7.86-7.79 (4H), 7.61-7.57 (3H).

[0107] [Synthesis Example 7: Synthesis of Compound (16)] In a reaction vessel, 4.8 g of white powder A, 4,4,5,5-tetramethyl-2-(2-(naphthalen-2-yl)-5-pyrimidyl)-1,3,2-dioxaborolane, 5.2 g of potassium carbonate, 0.6 g of catalyst A, 48 mL of toluene, 12 mL of ethanol, and 24 mL of water were added, and the mixture was stirred under reflux for 1 hour. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (16): 6.4 g (pale yellow powder, yield: 92%). 1 H-NMR(CDCl3): δ(ppm)=9.71(2H), 9.13(1H), 8.74-8.76(2H), 8.66(1H), 8.51 (4H), 8.41(1H), 8.12-8.15(2H), 7.90-8.06(3H), 7.55-7.61(5H), 7.41(1H).

[0108] [Synthesis Example 8: Synthesis of Compound (60)] 5.0 g of 2,6-dichloro-4-(naphthalene-1-yl)pyrimidine, 12.9 g of starting material 1, 7.5 g of potassium carbonate, 0.8 g of catalyst A, 50 mL of toluene, 13 mL of ethanol, and 25 mL of water were added to a reaction vessel and stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (60): 7.4 g (yellow powder, yield: 82%). 1 H-NMR (CDCl3): δ (ppm) = 8.91 (2H), 8.46-8.51 (6H), 8.35-8.42 (3H), 7.99-8.14 (5H), 7.86 (1H), 7.58-7.68 (3H), 7.39 (2H).

[0109] [Synthesis Example 9: Synthesis of Compound (62)] 6.0 g of 2-chloro-6-(naphthalene-1-yl)-4-[p-(quinoxaline-2-yl)phenyl]pyrimidine, 4.8 g of starting material 1, 3.8 g of potassium carbonate, 0.6 g of catalyst A, 60 mL of toluene, 15 mL of ethanol, and 30 mL of water were added to a reaction vessel and stirred under reflux for 3 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (62): 4.2 g (yellow powder, yield: 51%). 1 H-NMR (CDCl3): δ (ppm) = 9.45 (1H), 8.92 (2H), 8.37-8.56 (8H), 8.00-8.23 (6H), 7.78-7.88 (3H), 7.67 (1H), 7.60 (2H), 7.39 (1H).

[0110] [Synthesis Example 10: Synthesis of Compound (74)] In a reaction vessel, 6.0 g of 2-chloro-6-(naphthalene-2-yl)-4-[p-(quinoline-3-yl)phenyl]pyrimidine, 4.8 g of starting material 1, 3.8 g of potassium carbonate, 0.4 g of [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct (catalyst B), 60 mL of tetrahydrofuran (THF), and 30 mL of water were added, and the mixture was stirred under reflux for 1 hour. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (74): 6.7 g (yellow powder, yield: 82%). 1 H-NMR(CDCl3): δ(ppm)=9.29(1H), 8.97(2H), 8.82(1H), 8.39-8.53(7H), 8.27(1H), 8.05-8.19(4H), 7.94-7.97(4H), 7.75-7.80(1H), 7.58-7.65(3H), 7.37-7.41(1H).

[0111] [Synthesis Example 11: Synthesis of Compound (81)] 5.3 g of 2-chloro-2',6-bis(naphthalene-2-yl)-4,5'-bipyrimidyl, 3.8 g of starting material 1, 3.3 g of potassium carbonate, 0.4 g of catalyst B, 55 mL of THF, and 15 mL of water were added to a reaction vessel and stirred under reflux for 3 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (81): 5.6 g (yellow powder, yield: 78%). 1 H-NMR(CDCl3): δ(ppm)=9.62(2H), 9.03(1H), 8.83(2H), 8.70(1H), 8.57(1H), 8. 32-8.39(4H), 8.09(1H), 7.90-8.03(5H), 7.84(2H), 7.49-7.54(4H), 7.31(1H).

[0112] [Synthesis Example 12: Synthesis of Compound (108)] In a reaction vessel, 2.7 g of 2-chloro-6-[4-(oxazolo[5,4-b]pyridine-2-yl)-phenyl]-4-(naphthalen-2-yl)-pyrimidine, 2.3 g of 4,4,5,5-tetramethyl-2-[2-(naphthalen-2-yl)-5-pyrimidinyl]-1,3,2-dioxaborane, 1.7 g of potassium carbonate, 0.2 g of catalyst B, 30 mL of THF, and 7 mL of water were added, and the mixture was stirred under reflux for 4 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (108): 3.3 g (yellow powder, yield: 86%). 1 H-NMR(CDCl3): δ(ppm)=10.06(2H), 9.12(1H), 8.81(1H), 8.66(1H), 8.50(4H), 8.40(2 H), 8.29(1H), 8.11(1H), 7.97-8.05(4H), 7.88-7.93(2H), 7.52-7.60(4H), 7.39(1H).

[0113] [Synthesis Example 13: Synthesis of Compound (124)] In a reaction vessel, 4.0 g of 2,6-dichloro-4-(naphthalen-2-yl)pyrimidine, 10.6 g of 4,4,5,5-tetramethyl-2-[2-(naphthalen-2-yl)-5-pyrimidinyl]-1,3,2-dioxaborane, 6.0 g of potassium carbonate, 0.7 g of catalyst A, 80 mL of toluene, 20 mL of ethanol, and 40 mL of water were added, and the mixture was stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (124): 7.7 g (yellow powder, yield: 87%). 1 H-NMR (CDCl3): δ (ppm) = 10.06 (2H), 9.70 (2H), 9.14 (2H), 8.84 (1H), 8.65-8.69 (2H), 8.39 (1H), 8.26 (1H), 7.89-8.08 (9H), 7.54-7.63 (6H).

[0114] [Synthesis Example 14: Synthesis of Compound (127)] In a reaction vessel, 4.0 g of 2,4-dichloro-6-(2-naphthalenyl)pyrimidine, 7.4 g of 2-cyano-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine, 5.0 g of potassium carbonate, 0.4 g of catalyst B, 50 mL of THF, and 20 mL of water were added, and the mixture was stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (127): 4.5 g (pale yellow powder, yield: 75%). 1 H-NMR (DMSO-d6): δ(ppm)=9.89(1H), 9.81(1H), 9.16-9.09(3H), 8.95(1H), 8.59(1H), 8.26(1H), 8.21(1H), 8.13-8.01(3H), 7.67-7.64(2H).

[0115] [Synthesis Example 15: Synthesis of Compound (134)] In a reaction vessel, 3.0 g of 2-[4-(2,6-dichloropyridine-4-yl)phenyl]oxazolo[5,4-b]pyridine, 3.4 g of quinoline-3-boronic acid, 2.4 g of potassium carbonate, 0.3 g of catalyst B, 30 mL of THF, and 8 mL of water were added, and the mixture was stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (134): 4.2 g (yellow powder, yield: 90%). 1 H-NMR(CDCl3): δ(ppm)=10.24(1H), 9.85(1H), 9.46(1H), 9.09(1H), 8.57-8.51(4H), 8.42( 1H), 8.29(1H), 8.22(2H), 8.14(1H), 8.06(2H), 7.87-7.79(2H), 7.70-7.62(2H), 7.42(1H).

[0116] [Synthesis Example 16: Synthesis of Compound (135)] In a reaction vessel, 5.5 g of 2-{4-[2-chloro-6-(2-naphthalenyl)pyrimidine-4-yl]phenyl}oxazolo[5,4-b]pyridine, 4.6 g of starting material 2, 3.5 g of potassium carbonate, 0.4 g of catalyst B, 55 mL of THF, and 14 mL of water were added, and the mixture was stirred under reflux for 5 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (135): 7.6 g (pale orange powder, yield: 100%). 1 H-NMR(CDCl3): δ(ppm)=9.32(1H), 8.94(2H), 8.84(1H), 8.57-8.51(4H), 8.47-8.40(3H), 8.27(1 H), 8.18(1H), 8.13(1H), 8.09-8.05(2H), 7.96-7.94(4H), 7.77(1H), 7.64-7.58(3H), 7.41(1H).

[0117] [Synthesis Example 17: Synthesis of Compound (136)] In a reaction vessel, 1.5 g of 2,4-dichloro-6-phenylpyrimidine, 4,4,5,5-tetramethyl-2-[2-(2-naphthalenyl)pyrimidine-5-yl]-1,3,2-dioxaborolane, 2.3 g of potassium carbonate, 0.2 g of catalyst B, 50 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 4 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (136): 3.5 g (pale yellow powder, yield: 92%). 1 H-NMR (DMSO-d6): δ(ppm)=10.08(2H), 10.04(2H), 9.17(2H), 8.91(1H), 8.65-8.61(4H), 8.20(2H), 8.13(2H), 8.03(2H), 7.70-7.62(7H).

[0118] [Synthesis Example 18: Synthesis of Compound (137)] In a reaction vessel, 2.5 g of 2,4-dichloro-6-[4-(2-naphthalenyl)phenyl]pyrimidine, 3.6 g of 2-cyano-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine, 2.5 g of potassium carbonate, 0.2 g of catalyst B, 50 mL of THF, and 20 mL of water were added, and the mixture was stirred under reflux for 3 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (137): 2.0 g (pale yellow powder, yield: 56%). 1 H-NMR (DMSO-d6): δ(ppm)=9.94(1H), 9.85(1H), 9.17(2H), 8.93(1H), 8.68(2H), 8.39(1H), 8.31(1H), 8.27(1H), 8.09-7.97(6H), 7.59-7.57(2H).

[0119] [Synthesis Example 19: Synthesis of Compound (138)] In a reaction vessel, 2.0 g of 2-{4-[2-chloro-6-(2-naphthalenyl)pyrimidine-4-yl]phenyl}oxazolo[5,4-b]pyridine, 1.2 g of 2-cyano-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine, 3.8 g of potassium carbonate, 0.1 g of catalyst B, 20 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 1 hour. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (138): 1.6 g (yellow powder, yield: 67%). 1 H-NMR(CDCl3): δ(ppm)=10.06(1H), 9.15(1H), 8.81(1H), 8.54-8.49(4H), 8.43-8.31( 2H), 8.34(1H), 8.14(1H), 8.07-8.05(2H), 7.97-7.90(2H), 7.63-7.61(2H), 7.42(1H).

[0120] [Synthesis Example 20: Synthesis of Compound (139)] In a reaction vessel, 2.5 g of 2-chloro-2',6-bis(naphthalene-2-yl)-4,5'-bipyrimidinyl, 1.6 g of 5-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)pyridine-2-carbonitrile, 1.6 g of potassium carbonate, 0.1 g of catalyst B, 40 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 3 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (139): 2.4 g (yellow powder, yield: 83%). 1 H-NMR (CDCl3): δ(ppm)=10.05-10.10(1H), 9.72-9.79(2H), 9.15(2H), 8.83(1H), 8.66-8.68(1H), 7.92-8.10(8H), 7.52-7.65(5H).

[0121] [Synthesis Example 21: Synthesis of Compound (140)] In a reaction vessel, 2.0 g of 2-chloro-4,6-bis(naphthalen-2-yl)pyrimidine, 2.2 g of 4,4,5,5-tetramethyl-2-[2-(naphthalen-2-yl)pyrimidine-5-yl]-1,3,2-dioxaborane, 1.5 g of sodium bicarbonate, 0.2 g of catalyst B, 40 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (140): 2.6 g (pale yellow powder, yield: 90%). 1 H-NMR(CDCl3): δ(ppm)=10.12(2H), 9.15(1H), 8.86(2H), 8.69(1H), 8.43(2 H), 8.37(1H), 8.05-8.08(5H), 8.01(1H), 7.91-7.96(3H), 7.55-7.62(6H).

[0122] [Synthesis Example 22: Synthesis of Compound (141)] In a reaction vessel, 2.0 g of 4-[2-chloro-6-(naphthalen-2-yl)pyrimidine-4-yl]benzonitrile, 2.3 g of 4,4,5,5-tetramethyl-2-[2-(naphthalen-2-yl)pyrimidine-5-yl]-1,3,2-dioxaborane, 1.6 g of potassium carbonate, 0.1 g of catalyst B, 40 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 4 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (141): 1.3 g (pale yellow powder, yield: 43%). 1 H-NMR (CDCl3): δ(ppm)=10.02(2H), 9.11(1H), 8.79(1H), 8.65(1H), 8.35-8.42(3H), 8.21(1H), 7.87-8.05(8H), 7.54-7.62(4H).

[0123] [Synthesis Example 23: Synthesis of Compound (142)] In a reaction vessel, 2.0 g of 2-chloro-4,6-di-2-naphthalenylpyrimidine, 2.0 g of 4-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-pyrimidinyl]benzonitrile, 1.5 g of potassium carbonate, 0.1 g of catalyst B, 40 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 2 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (142): 1.8 g (pale yellow powder, yield: 63%). 1 H-NMR (CDCl3): δ (ppm) = 10.10 (2H), 8.83 (2H), 8.72 (2H), 8.73-8.39 (3H), 8.07-8.04 (4H), 7.96-7.94 (2H), 7.83 (2H), 7.62-7.60 (4H).

[0124] [Synthesis Example 24: Synthesis of Compound (143)] In a reaction vessel, 2.0 g of 2-chloro-4,6-di-(naphthalene-2-yl)pyrimidine, 2.1 g of 6-[5-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)pyrimidyl]-2-naphthalenecarbonitride, 1.5 g of potassium carbonate, 90 mg of catalyst B, 30 mL of THF, and 10 mL of water were added, and the mixture was stirred overnight under reflux. The solvent was removed by distillation, methanol and water were added, and the precipitate was filtered off to obtain the crude product. The obtained crude product was purified using activated clay in the same manner as in Synthesis Example 1. The obtained filtrate was allowed to cool to room temperature, and the precipitated solid was filtered off. Acetone was added and washed under reflux to obtain compound (143): 2.0 g (milky white powder, yield: 65%). 1 H-NMR(CDCl3): δ(ppm)=10.16(2H), 9.20(1H), 8.87(2H), 8.86-8.82(1H), 8.48-8.42(2H), 8.42(1 H), 8.31(1H), 8.16-8.11(1H), 8.11-8.05(5H), 8.01-7.93(2H), 7.72-7.66(1H), 7.66-7.59(4H).

[0125] [Synthesis Example 25: Synthesis of Compound (144)] In a reaction vessel, 2.0 g of 2-chloro-4,6-bis(naphthalene-2-yl)pyrimidine, 2.2 g of 4,4,5,5-tetramethyl-2-(2-phenylquinoxaline-6-yl)-1,3,2-dioxaborane, 1.5 g of potassium carbonate, 0.2 g of catalyst B, 40 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 19 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (144): 1.6 g (pale yellow powder, yield: 53%). 1 H-NMR(CDCl3):δ(ppm)=9.62(1H),9.44(1H),9.27(1H),8.91(2H),8.52(2H), 8.35-8.40(2H), 8.27-8.30(2H), 8.06-8.13(4H), 7.96(2H), 7.57-7.64(7H).

[0126] [Synthesis Example 26: Synthesis of Compound (145)] In a reaction vessel, 2.0 g of 4-[2-chloro-6-(naphthalene-2-yl)pyrimidine-4-yl]benzonitrile, 2.3 g of 4,4,5,5-tetramethyl-2-(2-phenylquinoxaline-6-yl)-1,3,2-dioxaborane, 1.2 g of potassium carbonate, 0.2 g of catalyst A, 50 mL of toluene, 5 mL of ethanol, and 10 mL of water were added, and the mixture was stirred under reflux for 3 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (145): 1.7 g (pale yellow powder, yield: 57%). 1 H-NMR(CDCl3):δ(ppm)=9.53(1H),9.42(1H),9.16(1H),8.84(1H),8.44-8.50 (3H), 8.23-8.33(4H), 8.04-8.09(2H), 7.95(1H), 7.89(2H), 7.57-7.64(5H).

[0127] [Synthesis Example 27: Synthesis of Compound (146)] In a reaction vessel, 2.5 g of 2-chloro-4,6-di-2-naphthalenylpyrimidine, 3.1 g of 4,4,5,5-tetramethyl-2-[2-(naphtho-2-yl)quinoxaline-6-yl]-1,3,2-dioxaborolane, 1.4 g of potassium carbonate, 0.2 g of catalyst B, 50 mL of toluene, 5 mL of ethanol, and 10 mL of water were added, and the mixture was stirred under reflux for 6 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (146): 4.0 g (pale yellow powder, yield: 100%). 1 H-NMR(CDCl3): δ(ppm)=9.64(1H), 9.60(1H), 9.29(1H), 8.92(2H), 8.76(1H), 8. 53(2H), 8.46(1H), 8.40(2H), 8.13-8.06(6H), 7.98-7.94(3H), 7.64-7.59(6H).

[0128] [Synthesis Example 28: Synthesis of Compound (147)] In a reaction vessel, 2.0 g of 2-chloro-4,6-di-2-naphthalenylpyrimidine, 2.3 g of 4-[6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2-quinoxalinyl]benzonitrile, 1.5 g of potassium carbonate, 0.1 g of catalyst B, 40 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 8 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (147): 2.5 g (pale yellow powder, yield: 81%). 1 H-NMR(CDCl3): δ(ppm)=9.62(1H), 9.43(1H), 9.29(1H), 8.89(2H), 8.50(2H), 8.42 -8.34(4H), 8.12-8.09(2H), 8.07(2H), 7.97-7.94(2H), 7.90(2H), 7.63-7.59(4H).

[0129] [Synthesis Example 29: Synthesis of Compound (148)] In a reaction vessel, 2.0 g of 2-chloro-4-[4-(naphthalene-2-yl)phenyl]-6-phenylpyrimidine, 2.0 g of 2-(4-cyanophenyl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)quinoxaline, 1.4 g of potassium carbonate, 80 mg of catalyst B, 30 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 1 hour. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (148): 2.6 g (milky white powder, yield: 86%). 1 H-NMR(CDCl3): δ(ppm)=9.58(1H), 9.44(1H), 9.27-9.21(1H), 8.55-8.46(2H), 8. 44-8.37(4H), 8.36-8.30(1H), 8.21-8.15(2H), 8.02-7.83(8H), 7.66-7.51(5H).

[0130] [Synthesis Example 30: Synthesis of Compound (149)] In a reaction vessel, 2.0 g of 2-chloro-4-[4-(naphthalene-2-yl)phenyl]-6-phenylpyrimidine, 1.3 g of 2-cyano-5-(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)pyrimidine, 1.4 g of potassium carbonate, 80 mg of catalyst B, 30 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 4 hours. The resulting crude product was dissolved in heated monochlorobenzene, activated clay was added, and the mixture was stirred for 30 minutes, after which it was filtered. n-hexane was added to the filtrate, and the precipitate obtained was collected by filtration to obtain compound (149): 0.89 g (white powder, yield: 38%). 1 H-NMR(CDCl3): δ(ppm)=10.05(2H), 8.44-8.37(2H), 8.33-8.27(2H), 8.23(1H), 8.16(1 H), 8.01-7.94(4H), 7.94-7.88(1H), 7.87-7.81(1H), 7.66-7.59(3H), 7.59-7.51(2H).

[0131] [Synthesis Example 31: Synthesis of Compound (150)] In a reaction vessel, 2.0 g of 2,4-dichloro-6-phenylpyrimidine, 6.0 g of 6-[(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl]-3-pyridinecarbonitride, 3.1 g of potassium carbonate, 0.2 g of catalyst B, 50 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 4 hours. The resulting crude product was dissolved in heated ODB, silica and activated clay were added, and the mixture was stirred for 30 minutes, after which it was filtered. After concentrating the filtrate, acetone was added and washed under reflux to obtain compound (150): 4.0 g (pale white powder, yield: 88%). 1 H-NMR(CDCl3): δ(ppm)=9.01(2H), 8.92-8.85(2H), 8.50-8.43(2H), 8.37-8.31(2 H), 8.31-8.21(4H), 8.13(1H), 8.11-8.04(2H), 8.01-7.95(2H), 7.65-7.56(3H).

[0132] [Synthesis Example 32: Synthesis of Compound (151)] In a reaction vessel, 2.0 g of 2,4-dichloro-6-(naphthalene-2-yl)pyrimidine, 4.9 g of 6-[(4,4,5,5-tetramethyl-1,3,2-dioxaboran-2-yl)phenyl]-3-pyridinecarbonitride, 2.5 g of potassium carbonate, 0.2 g of catalyst B, 50 mL of THF, and 10 mL of water were added, and the mixture was stirred under reflux for 4 hours. The resulting crude product was purified using activated clay in the same manner as in Synthesis Example 1 to obtain compound (151): 3.6 g (white powder, yield: 88%). 1 H-NMR(CDCl3): δ(ppm)=9.02(2H), 8.95-8.89(2H), 8.83(1H), 8.54-8.47(2H), 8. 47-8.40(1H), 8.33-8.23(5H), 8.11-8.03(4H), 8.01-7.92(3H), 7.65-7.56(2H).

[0133] (Measurement of melting point and glass transition temperature) The melting point and glass transition temperature (Tg) of the compounds according to the present invention obtained in Synthesis Examples 1-13 and 15-32, as well as comparative compounds (B-1) and (B-2) with the following structures, were measured using a high-sensitivity differential scanning calorimeter (manufactured by Rigaku Holdings Ltd., product name: DSCvesta Thermó plus EV02 series). The measurement results are shown in Table 1. As shown in Table 1, it was found that the pyrimidine compounds according to the present invention obtained in Synthesis Examples 1-13 and 15-32 all had high melting points and many did not have a glass transition temperature. This result indicates that the pyrimidine compounds according to the present invention are stable in a thin film state and have excellent durability.

[0134] [ka]

[0135] (Measurement of refractive index and extinction coefficient) A glass substrate was placed in a vacuum deposition machine and the pressure was reduced to 0.001 Pa or less. The compounds according to the present invention obtained in Synthesis Examples 1-13 and 15-32, as well as Alq3, compound (B-1), and compound (B-2) as comparative compounds, were deposited onto the glass substrate at a deposition temperature of 1.0 Å / sec to produce a 60 nm thick deposited film. The refractive index n and extinction coefficient k of the prepared deposited film were measured at room temperature (25 ± 2°C) at wavelengths of 450 nm and 750 nm using a spectroscopic ellipsometer (JAWoollam, model: M-2000U). The measurement results are shown in Table 1.

[0136] [Table 1]

[0137] As shown in Table 1, the extinction coefficient in the wavelength range of 450 nm to 750 nm was equivalent for the comparative compound and the compound according to the present invention. On the other hand, the refractive index in the wavelength range of 450 nm to 750 nm was equal to or greater than that of the comparative compound for all compounds according to the present invention. These results suggest that using the pyrimidine compound of the present invention as a constituent material for the capping layer contributes to improving the light extraction efficiency in organic EL devices.

[0138] [Example 1: Fabrication of an Organic EL Device] An organic EL device having the configuration shown in Figure 1 was fabricated by sequentially depositing a hole injection layer 3, a hole transport layer 4, a light-emitting layer 5, an electron transport layer 6, an electron injection layer 7, a cathode 8, and a capping layer 9 onto a glass substrate 1 on which a reflective ITO electrode was pre-formed as a transparent anode 2.

[0139] Specifically, a glass substrate 1, on which a 50 nm thick ITO film, a 100 nm thick silver alloy reflective film, and a 5 nm thick ITO film were sequentially deposited, was ultrasonically cleaned in isopropyl alcohol for 20 minutes, and then dried on a hot plate heated to 250°C for 10 minutes. After that, UV ozone treatment was performed for 2 minutes, and the resulting ITO-coated glass substrate was placed in a vacuum deposition machine and the pressure was reduced to 0.001 Pa or less. Subsequently, a hole injection layer 3 with a thickness of 10 nm was formed by binary deposition of an electron acceptor (Acceptor-1) and a compound (HTM-1) with the following structure, covering the transparent anode 2, at a deposition rate ratio of Acceptor-1:HTM-1 = 3:97. On the hole injection layer 3, the above compound (HTM-1) was deposited as a hole transport layer 4 to a thickness of 140 nm. On the hole transport layer 4, a light-emitting layer 5 with a thickness of 20 nm was formed by binary deposition of compounds (EMD-1) and (EMH-1) with the following structures at a deposition rate ratio of EMD-1:EMH-1=5:95. On the light-emitting layer 5, an electron transport layer 6 with a thickness of 30 nm was formed by binary deposition of compounds (ETM-1) and (ETM-2) with the following structures at a deposition rate ratio of ETM-1:ETM-2=50:50. On the electron transport layer 6, lithium fluoride was deposited as an electron injection layer 7 to a thickness of 1 nm. On the electron injection layer 7, a magnesium-silver alloy was deposited as a cathode 8 to a thickness of 12 nm. Finally, compound (1) from synthesis example 1 was deposited as a capping layer 9 to a thickness of 60 nm.

[0140] [ka]

[0141] [Examples 2-31 and Comparative Examples 1-3] Organic EL elements according to Examples 2-31 and Comparative Examples 1-3 were fabricated in the same manner as in Example 1, except that the capping layer was formed using the compounds obtained in Synthesis Examples 2-13 and 15-32, as well as Alq3, compound (B-1), and compound (B-2) as comparative compounds, respectively, instead of compound (1) obtained in Synthesis Example 1. The fabricated organic EL elements were subjected to a DC voltage (current density: 10 mA / cm²) in air at room temperature. 2 The luminescence characteristics were evaluated by applying ) . In addition, the device lifetime was measured using the fabricated organic EL element. In this invention, the device lifetime is defined as a current density of 10 mA / cm². 2 This value is expressed as the time it takes for the brightness to decay to 95% of the initial brightness (100%) when driven with a constant current. The measurement results are summarized in Table 2.

[0142] [Table 2]

[0143] As shown in Table 2, the current density is 10 mA / cm². 2 While the driving voltage was almost the same for the organic EL elements of Comparative Examples 1-3 and Examples 1-6, the brightness, luminous efficiency, power efficiency, and element lifespan were significantly improved in all examples compared to the organic EL elements of the comparative examples. This result indicates that the pyrimidine compound of the present invention is a suitable material for use in the capping layer, and that the light extraction efficiency of the organic EL element can be greatly improved by increasing the refractive index of the capping layer. [Industrial applicability]

[0144] The pyrimidine compounds of the present invention have a high refractive index, significantly improve light extraction efficiency, and maintain a stable thin film state, making them excellent compounds for use in the capping layer of organic EL elements. Furthermore, organic EL elements fabricated using the pyrimidine compounds of the present invention can achieve high efficiency. Moreover, using the compounds of the present invention, which do not have absorption in the blue, green, and red wavelength regions, is particularly suitable for displaying images with high color purity, sharpness, and brightness. The present invention is expected to have applications, for example, in home appliances and lighting. [Explanation of Symbols]

[0145] 1. Glass substrate 2 transparent anode 3. Hole injection layer 4. Hole transport layer 5. Emitting layer 6 Electron transport layer 7 Electron injection layer 8 cathode 9. Capping layer

Claims

1. An organic electroluminescent element having an anode, a hole transport layer, a light-emitting layer, an electron transport layer, a cathode, and a capping layer in this order, wherein the capping layer contains a pyrimidine compound represented by the following general formula (I): 【Chemistry 1】 Here, Ar １ and Ar ２ Each of these independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, Ar １ and Ar ２ At least one of these represents a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted imidazopyridyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, Ar ３ This represents a substituted phenyl group having only one cyano group as a substituent (unsubstituted cyanophenyl group), a substituted pyridyl group having only one cyano group as a substituent (unsubstituted cyanopyridyl group), an unsubstituted aryl group, or an unsubstituted heteroaryl group. L １ and L ２ Each of these independently represents a single bond, an unsubstituted arylene group, or an unsubstituted heteroarylene group. X １ , X ２ and X ３ each independently represent a nitrogen atom or an unsubstituted methine group (-CH=), and X １ , X ２ and X ３ any two of them are nitrogen atoms, and the remaining one is a methine group.

2. In the above general formula (I), Ar ３ The organic electroluminescent element according to claim 1, wherein the group is an unsubstituted cyanophenyl group, an unsubstituted cyanopyridyl group, an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted phenanthryl group, an unsubstituted pyridyl group, an unsubstituted quinolyl group, an unsubstituted quinoxalinyl group, or an unsubstituted imidazopyridyl group.

3. In the above general formula (I), L １ and L ２ The organic electroluminescent element according to claim 1, wherein each of the groups is independently a single bond or an unsubstituted phenylene group, an unsubstituted naphthylene group, an unsubstituted pyridinediyl group, an unsubstituted pyrimidinediyl group, an unsubstituted quinoxalinediyl group, and an unsubstituted oxazolopyridinediyl group.

4. In the above general formula (I), Ar １ and Ar ２ The organic electroluminescent element according to claim 1, wherein each of these groups is independently a substituted pyridyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted imidazopyridyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group.

5. In the above general formula (I), Ar １ However, it is a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted quinoxalinyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, and L １ The organic electroluminescent element according to claim 1, wherein the bond is a single bond, or an unsubstituted phenylene group or an unsubstituted biphenylylene group.

6. The organic electroluminescent element according to claim 1, wherein a film of the compound represented by the general formula (I) is deposited on a glass substrate to a thickness of 60 nm by vacuum deposition, and the refractive index measured at room temperature (25 ± 2 °C) using spectroscopic ellipsometry is 2.00 or higher in the wavelength range of 450 nm to 750 nm.

7. The organic electroluminescent element according to any one of claims 1 to 6, wherein the capping layer is a laminated or mixed layer containing two or more compounds including the pyrimidine compound represented by the general formula (I).

8. An electronic element or electronic device having a pair of electrodes and at least one organic layer, wherein the organic layer contains a compound represented by the following general formula (I): 【Chemistry 2】 Here, Ar １ and Ar ２ Each of these independently represents a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, Ar １ and Ar ２ At least one of these represents a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted imidazopyridyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, Ar ３ This represents a substituted phenyl group having only one cyano group as a substituent (unsubstituted cyanophenyl group), a substituted pyridyl group having only one cyano group as a substituent (unsubstituted cyanopyridyl group), an unsubstituted aryl group, or an unsubstituted heteroaryl group. L １ and L ２ Each of these independently represents a single bond, an unsubstituted arylene group, or an unsubstituted heteroarylene group. X １ , X ２ and X ３ Each of these independently represents a nitrogen atom or an unsubstituted methine group (-CH=), and X １ , X ２ and X ３ Two of them are nitrogen atoms, and the remaining one is a methine group.

9. Pyrimidine compounds represented by the following general formula (II): 【Transformation 3】 Here, Ar １ represents a substituted or unsubstituted oxazolo[5,4-b]pyridyl group, and Ar ２ Ar represents a substituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted quinolyl group, a substituted or unsubstituted quinoxalinyl group, or a substituted or unsubstituted oxazolo[5,4-b]pyridyl group. ３ This represents a substituted phenyl group having only one cyano group as a substituent (unsubstituted cyanophenyl group), a substituted pyridyl group having only one cyano group as a substituent (unsubstituted cyanopyridyl group), an unsubstituted phenyl group, an unsubstituted naphthyl group, an unsubstituted phenanthryl group, an unsubstituted pyridyl group, an unsubstituted quinolyl group, or an unsubstituted quinoxalinyl group. L １ and L ２ Each of these independently represents a single bond or an unsubstituted arylene group. X １ , X ２ and X ３ Each of these independently represents a nitrogen atom or an unsubstituted methine group (-CH=), and X １ , X ２ and X ３ Two of them are nitrogen atoms, and the remaining one is a methine group.

10. In the above general formula (II), L １ and L ２ The pyrimidine compound according to claim 9, wherein each is independently a single bond, an unsubstituted phenylene group, an unsubstituted biphenylylene group, or an unsubstituted naphthylene group.

11. In the above general formula (II), Ar １ is an unsubstituted oxazolo[5,4-b]pyridyl group, L １ The pyrimidine compound according to claim 9, wherein is an unsubstituted phenylene group.

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