COMPOUND HAVING BENZAZOLE RING STRUCTURE, AND ORGANIC ELECTROLUMINESCENT DEVICE

Abstract

An object of the present invention is to provide, as a material for a highly efficient and highly durable organic EL element, an organic compound that has excellent properties, including excellent electron-injecting/transporting capability, hole-blocking capability, and high stability in the form of a thin film. Another object of the present invention is to provide a highly efficient and highly durable organic EL element by using this compound. The present invention focuses on the properties of the benzazole ring, which has affinity for electrons, and specifically focuses on the capability of its nitrogen atom to coordinate to a metal and also on excellent heat resistance. The inventors have thus designed and chemically synthesized various compounds having a benzazole ring structure, and then experimentally produced organic EL elements including the compounds, followed by thoroughly evaluating the characteristics thereof. As a result, it has been found that it is possible to obtain an organic EL element having excellent properties by using a specific compound having a benzazole ring structure.

Claims

1. A compound having a benzazole ring structure and represented by the general formula (a-1): ##STR00070## where a plurality of R are the same or different, and represent a group represented by the structural formula (b-1) below, a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a cyano group, a nitro group, a trimethylsilyl group, a triphenylsilyl group, a diphenylphosphinyl group, a diphenylphosphine oxide group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group, a linear or branched alkyl group having 1 to 6 carbon atoms and optionally having a substituent, a cycloalkyl group having 5 to 10 carbon atoms and optionally having a substituent, a linear or branched alkenyl group having 2 to 6 carbon atoms and optionally having a substituent, a linear or branched alkyloxy group having 1 to 6 carbon atoms and optionally having a substituent, or a cycloalkyloxy group having 5 to 10 carbon atoms and optionally having a substituent, X represents an oxygen atom or a sulfur atom, a plurality of Y are the same or different, and represent a carbon atom having R, or a nitrogen atom, and at least one R is a group represented by the structural formula (b-1):
- - - L.sub.1-L.sub.2-(CN).sub.n  (b-1) where L.sub.1 and L.sub.2 are the same or different, and represent a single bond, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, or a substituted or unsubstituted fused polycyclic aromatic group, n is an integer 1 or 2, and the dashed line indicates a binding site.

2. The compound having a benzazole ring structure as set forth in claim 1, represented by the general formula (a-2): ##STR00071## where R and Y are as defined in the general formula (a-1).

3. The compound having a benzazole ring structure as set forth in claim 2, represented by the general formula (a-3): ##STR00072## where R is as defined in the general formula (a-1).

4. The compound having a benzazole ring structure as set forth in claim 3, represented by the general formula (a-4): ##STR00073## where R is as defined in the general formula (a-1).

5. The compound having a benzazole ring structure as set forth in claim 4, represented by the general formula (a-5): ##STR00074## where R is as defined in the general formula (a-1).

6. The compound having a benzazole ring structure as set forth in claim 1, represented by the general formula (a-6): ##STR00075## where R is as defined in the general formula (a-1).

7. The compound having a benzazole ring structure as set forth in claim 6, represented by the general formula (a-7): ##STR00076## where R is as defined in the general formula (a-1).

8. The compound having a benzazole ring structure as set forth in claim 1, wherein n in the structural formula (b-1) is an integer 1.

9. The compound having a benzazole ring structure as set forth in claim 1, wherein L.sub.2 in the structural formula (b-1) is a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenylene group.

10. An organic electroluminescent element comprising a pair of electrodes and one or more organic layers sandwiched therebetween, wherein the compound having a benzazole ring structure as set forth in claim 1 is included in at least one of the organic layers.

11. The organic electroluminescent element as set forth in claim 10, wherein the organic layer including the compound having a benzazole ring structure is an electron-transporting layer.

12. The organic electroluminescent element as set forth in claim 10, wherein the organic layer including the compound having a benzazole ring structure is a hole-blocking layer.

13. The organic electroluminescent element as set forth in claim 10, wherein the organic layer including the compound having a benzazole ring structure is a light-emitting layer.

14. The organic electroluminescent element as set forth in claim 10, wherein the organic layer including the compound having a benzazole ring structure is an electron-injecting layer.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0078] FIG. 1 shows the structures of Compounds 1 to 15 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0079] FIG. 2 shows the structures of Compounds 16 to 33 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0080] FIG. 3 shows the structures of Compounds 34 to 51 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0081] FIG. 4 shows the structures of Compounds 52 to 69 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0082] FIG. 5 shows the structures of Compounds 70 to 84 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0083] FIG. 6 shows the structures of Compounds 85 to 96 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0084] FIG. 7 shows the structures of Compounds 97 to 107 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0085] FIG. 8 shows the structures of Compounds 108 to 124 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0086] FIG. 9 shows the structures of Compounds 125 to 139 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0087] FIG. 10 shows the structures of Compounds 140 to 154 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0088] FIG. 11 shows the structures of Compounds 155 to 169 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0089] FIG. 12 shows the structures of Compounds 170 to 184 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0090] FIG. 13 shows the structures of Compounds 185 to 200 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0091] FIG. 14 shows the structures of Compounds 201 to 204 as examples of the compound having a benzazole ring structure represented by the general formula (a-1).

[0092] FIG. 15 shows the configuration of organic EL elements of Examples 58 to 112 and Comparative Examples 1 and 2.

DESCRIPTION OF EMBODIMENTS

[0093] In the present invention, X in the general formula (a-1) above is preferably an oxygen atom in view of hole-blocking capability and electron-transporting capability. That is to say, the compound of the present invention is preferably the compound having a benzazole ring structure and represented by the general formula (a-2) above.

[0094] Furthermore, Y is preferably a carbon atom having R. In other words, the compound of the present invention is more preferably the compound having a benzazole ring structure and represented by the general formula (a-3) above.

[0095] In view of stability in the form of a thin film, R in the general formula (a-1) above is preferably a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted fused polycyclic aromatic group, or a group represented by the structural formula (b-1) above.

[0096] Specifically, the compound of the present invention is preferably the compound having a benzazole ring structure and represented by the general formula (a-4) above, and more preferably the compound having a benzazole ring structure represented by the general formula (a-5) above.

[0097] In view of hole-blocking capability and electron-transporting capability, L.sub.1 and L.sub.2 in the structural formula (b-1) above are preferably a group selected from a substituted or unsubstituted phenylene group, a substituted or unsubstituted biphenylene group, a substituted or unsubstituted terphenylene group, a substituted or unsubstituted naphthylene group, and a substituted or unsubstituted fluorenylene group. Furthermore, L.sub.2 in the structural formula (b-1) above is preferably a substituted or unsubstituted phenylene group, or a substituted or unsubstituted biphenylene group.

[0098] Preferable examples of the group represented by the structural formula (b-1) above include groups represented by the structural formulae below:

##STR00008##

[0099] where the dashed lines each indicate a binding site.

[0100] In view of hole-blocking capability and electron-transporting capability, the substituted or unsubstituted aromatic hydrocarbon group, the substituted or unsubstituted aromatic heterocyclic group, and the substituted or unsubstituted fused polycyclic aromatic group represented by R in the general formula (a-1) are preferably a phenyl group, a naphthyl group, a phenanthrenyl group, a spirobifluorenyl group, a pyridyl group, a substituted or unsubstituted fluorenyl group, or a substituted or unsubstituted triazinyl group, or a group obtained by combining any of these groups with a phenylene group.

[0101] Preferable examples of the group represented by R in the general formula (a-1) include groups represented by the structural formulae below:

##STR00009##

[0102] where the dashed lines each indicate a binding site.

[0103] Specific preferred examples of the compound having a benzazole ring structure represented by the general formula (a-1) above, which is favorably used for the organic EL element of the present invention, are shown in FIGS. 1 to 14, but the present invention is not limited to these compounds.

[0104] The compound having a benzazole ring structure of the present invention is a novel compound. These compounds can be synthesized, for example, according to known methods as in the following manner (see Patent Literatures 5 and 6, and Non-Patent Literatures 6 and 7, for example).

##STR00010##

[0105] The compounds having a benzazole ring structure represented by the general formulae (a-1) to (a-7) can be purified using a purification method such as column chromatography, adsorption using silica gel, activated carbon, activated clay, or others, recrystallization or crystallization from a solvent; or sublimation. The compound can be identified by NMR analysis. The physical properties can be measured in terms of melting point, glass transition point (Tg), work function, and the like. The melting point is a measure of vapor deposition properties, the glass transition point (Tg) is a measure of stability in the form of a thin film, and the work function is a measure of hole-transporting capability and hole-blocking capability.

[0106] The melting point and the glass transition point (Tg) can be measured on the compound in the form of a powder using a high-sensitivity differential scanning calorimeter (DSC3100SA manufactured by Bruker AXS K.K.), for example.

[0107] The work function can be measured on the compound in the form of a thin film with a thickness of 100 nm formed on an ITO substrate using an ionization potential measuring device (PYS-202 manufactured by Sumitomo Heavy Industries, Ltd.), for example.

[0108] The organic EL element of the present invention may have a structure in which an anode, a hole-injecting layer, a hole-transporting layer, a light-emitting layer, an electron-transporting layer, an electron-injecting layer, and a cathode sequentially are sequentially provided on a substrate; and the structure may further include an electron-blocking layer between the hole-transporting layer and the light-emitting layer; and also may further include a hole-blocking layer between the light-emitting layer and the electron-transporting layer. In these multilayer structures, a single organic layer may perform the functions of some layers. For example, a single organic layer may serve as both the hole-injecting layer and the hole-transporting layer, and a single organic layer may serve as both the electron-injecting layer and the electron-transporting layer. Moreover, it is possible to stack two or more organic layers having the same function. Specifically, two hole-transporting layers may be stacked; two light-emitting layers may be stacked; and two electron-transporting layers may be stacked.

[0109] An electrode material having a high work function, such as ITO or gold, is used for the anode of the organic EL element of the present invention.

[0110] Examples of a material used for the hole-injecting layer of the organic EL element of the present invention include porphyrin compounds typified by copper phthalocyanine, starburst triphenylamine derivatives; arylamine compounds having a structure containing two or more triphenylamine structures or carbazolyl structures in the molecule, the triphenylamine or carbazolyl structures being linked to each other via a single bond or a divalent group having no heteroatom; heterocyclic compounds of acceptor type, such as hexacyanoazatriphenylene; and polymer materials of coating type.

[0111] Examples of a material used for the hole-transporting layer of the organic EL element of the present invention include benzidine derivatives such as N,N′-diphenyl-N,N′-di(m-tolyl)-benzidine (hereinafter abbreviated as “TPD”), N,N′-diphenyl-N,N′-di(α-naphthyl)-benzidine (hereinafter abbreviated as “NPD”), and N,N,N′,N′-tetrabiphenylyl benzidine, 1,1-bis[(di-4-tolylamino)phenyl] cyclohexane (hereinafter abbreviated as “TAPC”); and arylamine compounds having a structure containing two or more triphenylamine structures or carbazolyl structures in the molecule, the triphenylamine or carbazolyl structures being linked to each other via a single bond or a divalent group containing no heteroatom.

[0112] It is also possible to use, as a material for the hole-injecting layer or the hole-transporting layer, polymer materials of coating type, such as poly(3,4-ethylenedioxythiophene) (hereinafter abbreviated as “PEDOT”)/poly(styrene sulfonate) (hereinafter abbreviated as “PSS”).

[0113] Furthermore, other examples of the material used for the hole-injecting layer or the hole-transporting layer include those obtained by p-doping a material normally used for these layers with trisbromophenylamine hexachloroantimony or a radialene derivative (see Patent Literature 7, for example); and a polymer compound having the structure of a benzidine derivative, such as TPD, as a partial structure thereof.

[0114] Examples of a material used for the electron-blocking layer of the organic EL element of the present invention include compounds having an electron blocking effect, such as carbazole derivatives such as 4,4′,4″-tri(N-carbazolyl)triphenylamine (hereinafter abbreviated as “TCTA”), 9,9-bis[4-(carbazole-9-yl)phenyl]fluorene, 1,3-bis(carbazole-9-yl)benzene (hereinafter abbreviate as “mCP”), and 2,2-bis(4-carbazole-9-ylphenyl)adamantane (hereinafter abbreviate as “Ad-Cz”), and compounds having a triphenylsilyl group and a triarylamine structure and typified by 9-[4-(carbazole-9-yl)phenyl]-9-[4-(triphenylsilyl)phenyl]-9H-fluorene.

[0115] Examples of a material used for the light-emitting layer of the organic EL element of the present invention include the compound having a benzazole ring structure of the present invention, and also metal complexes of quinolinol derivatives such as Alq.sub.3, various types of metal complexes, an anthracene derivative, a bisstyrylbenzene derivative, a pyrene derivative, an oxazole derivative, and a poly(p-phenylene vinylene) derivative. The light-emitting layer may include a host material and a dopant material. As the host material, an anthracene derivative is preferably used. Other examples of the host material include the above-listed light emitting materials including the compound having a benzazole ring structure of the present invention, and also a heterocyclic compound having an indole ring as a partial structure of a fused ring; a heterocyclic compound having a carbazole ring as a partial structure of a fused ring; a carbazole derivative; a thiazole derivative; a benzimidazole derivative; and a polydialkylfluorene derivative. Examples of the dopant material include quinacridone, coumarin, rubrene, perylene, and derivatives thereof, a benzopyran derivative; a rhodamine derivative; and an aminostyryl derivative.

[0116] A phosphorescent emitter can also be used as the material for the light-emitting layer. The phosphorescent emitter may be a metal complex of iridium, platinum, or the like, and examples thereof include a green phosphorescent emitter such as Ir(ppy).sub.3, a blue phosphorescent emitter such as FIrpic or FIr6, and a red phosphorescent emitter such as Btp.sub.2Ir (acac). As a host material in this case, a host material having hole-injecting/transporting capability may be used, including carbazole derivatives such as 4,4′-di(N-carbazolyl)biphenyl (hereinafter abbreviated as “CBP”), TCTA, and mCP, and also the compound having a benzazole ring structure of the present invention, and also, a host material having electron-transporting capability may be used, including p-bis(triphenylsilyl)benzene (hereinafter abbreviated as “UGH2”) and 2,2′,2″-(1,3,5-phenylene)-tris(1-phenyl-1H-benzimidazole) (hereinafter abbreviated as “TPBI”). Use of these materials enables production of a high-performance organic EL element.

[0117] In order to avoid concentration quenching, doping of the host material with a phosphorescent material is preferably performed by co-deposition in an amount within a range of 1 to 30 wt % based on the entire light-emitting layer.

[0118] As the light emitting material, a material that emits delayed fluorescence can also be used, including CDCB derivatives such as PIC-TRZ, CC2TA, PXZ-TRZ, and 4CzIPN (see Non-Patent Literature 3, for example).

[0119] Examples of a material used for the hole-blocking layer of the organic EL element of the present invention include the compound having a benzazole ring structure of the present invention, and also compounds exhibiting a hole-blocking effect, including a phenanthroline derivative, such as bathocuproine (hereinafter abbreviated as “BCP”); a metal complex of a quinolinol derivative, such as BAlq; various types of rare-earth complexes; an oxazole derivative; a triazole derivative; and a triazine derivative. These materials may also serve as the material for the electron-transporting layer.

[0120] Examples of a material used for the electron-transporting layer of the organic EL element of the present invention include the compound having a benzazole ring structure of the present invention, and also metal complexes of quinolinol derivatives, such as Alq.sub.3 and BAlq; various types of metal complexes; a triazole derivative; a triazine derivative; an oxadiazole derivative; a pyridine derivative; a benzimidazole derivative; a thiadiazole derivative; an anthracene derivative; a carbodiimide derivative; a quinoxaline derivative; a pyridoindole derivative; a phenanthroline derivative; a silole derivative.

[0121] Examples of a material used for the electron-injecting layer of the organic EL element of the present invention include the compound having a benzazole ring structure of the present invention, and also 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). The electron-injecting layer can however be omitted when the electron-transporting layer and a cathode are suitably selected.

[0122] Furthermore, a material obtained by n-doping a material normally used for an electron-injecting layer or an electron-transporting layer with a metal such as cesium can be used as the material for the electron-injecting layer or the electron-transporting layer.

[0123] Examples of an electrode material used for the cathode of the organic EL element of the present invention include an electrode material having a low work function, such as aluminum; and an alloy having an even lower work function, such as a magnesium-silver alloy, a magnesium-indium alloy, and an aluminum-magnesium alloy.

[0124] The above-described materials for the layers constituting the organic EL element can be formed into a thin film using a known method such as vapor deposition, spin coating, or inkjet printing.

[0125] These materials may be used singly for film formation, or two or more of these materials may be mixed and used for film formation. In each case, a single layer may be formed. Any layer may have a layered structure composed of different layers each formed of a single kind of material, a layered structure composed of different layers each formed of a mixture of materials, or a layered structure composed of a layer formed of a single kind of material and a layer formed of a mixture of two or more of materials.

EXAMPLES

[0126] Hereinafter, embodiments of the present invention will be described in greater detail by way of examples. However, the present invention is not limited to Examples below unless the gist thereof is exceeded.

Example 1

Synthesis of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(4′-cyano-biphenyl-4-yl)-benzoxazole (Compound-2)

[0127] First, 8.8 g of 2-(4-chlorophenyl)-4,6-bis(4-naphthalene-1-yl-phenyl)-benzoxazole, 3.2 g of 4-cyanophenylboronic acid, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), 0.4 g of tricyclohexylphosphine, and 5.4 g of tripotassium phosphate were place in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of monochlorobenzene/acetone to thereby obtain 7.2 g (yield: 83%) of a pale yellow powder of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(4′-cyano-biphenyl-4-yl)-benzoxazole (Compound-2).

##STR00011##

[0128] The structure of the obtained pale yellow powder was identified using NMR.

[0129] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0130] δ (ppm)=8.52 (2H), 8.33 (2H), 8.13 (1H), 8.05 (1H), 8.04 (1H), 8.01-7.88 (7H), 7.85-7.78 (6H), 7.75 (2H), 7.70 (2H), 7.65-7.47 (8H)

Example 2

Synthesis of 4,6-bis(phenanthrene-9-yl)-2-(4′-cyano-biphenyl-4-yl)-benzoxazole (Compound-10)

[0131] First, 10.0 g of 2-(4-chloro-phenyl)-4,6-bis(phenanthrene-9-yl)-benzoxazole, 3.0 g of 4-cyanophenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 7.3 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 4.0 g (yield: 36%) of a white powder of 4,6-bis(phenanthrene-9-yl)-2-(4′-cyano-biphenyl-4-yl)-benzoxazole (Compound-10).

##STR00012##

[0132] The structure of the obtained white powder was identified using NMR.

[0133] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0134] δ (ppm)=8.85 (2H), 8.79 (2H), 8.35 (2H), 8.17 (1H), 8.05 (1H), 8.04 (1H), 7.98 (2H), 7.91 (2H), 7.80-7.58 (12H), 7.65 (2H), 7.59 (1H)

Example 3

Synthesis of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4,6-di(naphthalene-1-yl)-benzoxazole (Compound-22)

[0135] First, 8.0 g of 4,6-bis(naphthalene-1-yl)-2-(4-chloro-phenyl)-benzoxazole, 6.1 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.8 g of tris(dibenzylideneacetone)dipalladium(0), 0.9 g of tricyclohexylphosphine, and 10.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 9.3 g (yield: 90%) of a white powder of 4,6-bis(naphthalene-1-yl)-2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole (Compound-22).

##STR00013##

[0136] The structure of the obtained white powder was identified using NMR.

[0137] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0138] δ (ppm)=8.36 (2H), 8.14 (1H), 8.03 (1H), 7.98 (3H), 7.94 (1H), 7.85 (1H), 7.84-7.69 (11H), 7.68 (2H), 7.61 (2H), 7.54 (3H), 7.48 (1H)

Example 4

Synthesis of 4,6-bis(biphenyl-4-yl)-2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole (Compound-23)

[0139] First, 11.4 g of 4,6-bis(biphenyl-4-yl)-2-(4-chloro-phenyl)-benzoxazole, 7.8 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 1.0 g of tris(dibenzylideneacetone)dipalladium(0), 1.2 g of tricyclohexylphosphine, and 13.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol and water were added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 13.7 g (yield: 95%) of a yellow powder of 4,6-bis(biphenyl-4-yl)-2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole (Compound-23).

##STR00014##

[0140] The structure of the obtained yellow powder was identified using NMR.

[0141] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0142] δ (ppm)=8.45 (2H), 8.26 (2H), 7.92 (1H), 7.90-7.67 (21H), 7.52 (4H), 7.42 (2H)

Example 5

Synthesis of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(4″-cyano-[1,1′,4′,1″ ]terphenyl-4-yl)-benzoxazole (Compound-24)

[0143] First, 8.0 g of 2-(4-chlorophenyl)-4,6-bis(4-naphthalene-1-yl-phenyl)-benzoxazole, 4.6 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), 0.4 g of tricyclohexylphosphine, and 5.4 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene to thereby obtain 3.2 g (yield: 32%) of a pale yellow powder of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(4″-cyano-[1,1′,4′,1,″ ]terphenyl-4-yl)-benzoxazole (Compound-24).

##STR00015##

[0144] The structure of the obtained pale yellow powder was identified using NMR.

[0145] In .sup.1H-NMR (CDCl.sub.3), the following signals of 36 hydrogens were detected.

[0146] δ (ppm)=8.50 (2H), 8.34 (2H), 8.13 (1H), 8.06 (2H), 8.02-7.91 (7H), 7.89 (2H), 7.84 (4H), 7.81-7.72 (6H), 7.70 (2H), 7.65-7.47 (8H)

Example 6

Synthesis of 2-[4-{4-(4′-cyano-biphenyl-4-yl)-naphthalene-1-yl}-phenyl]-4,6-diphenyl-benzoxazole (Compound-27)

[0147] First, 6.8 g of 2-(4-chloro-phenyl)-4, 6-diphenyl-benzoxazole, 8.1 g of 4′-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-naphthalene-1-yl}-biphenyl-4-carbonitrile, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 7.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, dichloromethane and water were added to the system, followed by extraction and separation to obtain an organic layer, and the organic layer was concentrated. The obtained concentrate was purified through column chromatography (carrier: silica gel, eluent: dichloromethane/n-heptane) to thereby obtain 7.3 g (yield: 63%) of a pale yellow powder of 2-[4-{4-(4′-cyano-biphenyl-4-yl)-naphthalene-1-yl}-phenyl]-4,6-diphenyl-benzoxazole (Compound-27).

##STR00016##

[0148] The structure of the obtained pale yellow powder was identified using NMR.

[0149] In .sup.1H-NMR (CDCl.sub.3), the following signals of 30 hydrogens were detected.

[0150] δ (ppm)=8.50 (2H), 8.17 (2H), 8.06 (2H), 7.88-7.66 (14H), 7.64-7.41 (10H)

Example 7

Synthesis of 2-(4′-cyano-biphenyl-4-yl)-6-{4-(4,6-diphenyl-[1,3,5]triazine-2-yl)-phenyl}-4-phenyl-benzoxazole (Compound-75)

[0151] First, 10.0 g of 2-(4-chlorophenyl)-6-{4-(4,6-diphenyl-[1,3,5]triazine-2-yl)-phenyl}-4-phenyl-benzoxazole, 2.6 g of 4-cyanophenylboronic acid, 0.8 g of tris(dibenzylideneacetone)dipalladium(0), 0.9 g of tricyclohexylphosphine, and 10.4 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, H.sub.2O was added for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through column chromatography (carrier: silica gel, eluent: dichloromethane/ethyl acetate) to thereby obtain 7.0 g (yield: 63%) of a pale yellow powder of 2-(4′-cyano-biphenyl-4-yl)-6-{4-(4,6-diphenyl-[1,3,5]triazine-2-yl)-phenyl}-4-phenyl-benzoxazole (Compound-75).

##STR00017##

[0152] The structure of the obtained pale yellow powder was identified using NMR.

[0153] In .sup.1H-NMR (CDCl.sub.3), the following signals of 29 hydrogens were detected.

[0154] δ (ppm)=8.91 (2H), 8.83 (4H), 8.45 (2H), 8.17 (2H), 7.93 (2H), 7.91 (2H), 7.79 (4H), 7.77 (2H), 7.70-7.57 (8H), 7.51 (1H)

Example 8

Synthesis of 2-(4′-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-77)

[0155] First, 10.6 g of 2-(4-chloro-phenyl)-4-phenyl-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole, 7.4 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.4 g of tricyclohexylphosphine, and 9.8 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, ethyl acetate and water were added to the system, followed by extraction and separation to obtain an organic layer, and the organic layer was concentrated. The obtained concentrate was purified through column chromatography (carrier: silica gel, eluent: dichloromethane/ethyl acetate) to thereby obtain 2.1 g (yield: 15%) of a pale yellow powder of 2-(4′-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-77).

##STR00018##

[0156] The structure of the obtained pale yellow powder was identified using NMR.

[0157] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0158] δ (ppm)=8.97 (1H), 8.66 (1H), 8.44 (2H), 8.16 (2H), 7.98 (1H), 7.90-7.71 (16H), 7.61 (2H), 7.49 (1H), 7.44 (1H)

Example 9

Synthesis of 2-(4′-cyano-biphenyl-4-yl)-6-{4-(4,6-diphenyl-[1,3,5]triazine-2-yl)-phenyl}-benzoxazole (Compound-84)

[0159] First, 15.0 g of 2-(4-chloro-phenyl)-6-{4-(4,6-diphenyl-[1,3,5]triazine-2-yl)-phenyl}-benzoxazole, 4.5 g of 4-cyanophenylboronic acid, 1.3 g of tris(dibenzylideneacetone)dipalladium(0), 1.6 g of tricyclohexylphosphine, and 17.8 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol and water were added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 5.3 g (yield: 31%) of a yellow powder of 2-(4′-cyano-biphenyl-4-yl)-6-{4-(4,6-diphenyl-[1,3,5] triazine-2-yl)-phenyl}-benzoxazole (Compound-84).

##STR00019##

[0160] The structure of the obtained yellow powder was identified using NMR.

[0161] In .sup.1H-NMR (CDCl.sub.3), the following signals of 25 hydrogens were detected.

[0162] δ (ppm)=8.93 (2H), 8.84 (4H), 8.44 (2H), 7.97 (1H), 7.92 (3H), 7.85-7.75 (7H), 7.68-7.59 (6H)

Example 10

Synthesis of 4-(biphenyl-4-yl)-6-(4′-cyano-biphenyl-4-yl)-2-([1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole (Compound-104)

[0163] First, 6.0 g of 6-chloro-4-(biphenyl-4-yl)-6-([1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole, 4.1 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), 0.3 g of tricyclohexylphosphine, and 4.8 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from mixed a solvent of monochlorobenzene/acetone to thereby obtain 2.1 g (yield: 28%) of a pale yellow powder of 4-(biphenyl-4-yl)-6-(4′-cyano-biphenyl-4-yl)-2-([1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole (Compound-104).

##STR00020##

[0164] The structure of the obtained pale yellow powder was identified using NMR.

[0165] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0166] δ (ppm)=8.44 (2H), 8.26 (2H), 7.91-7.66 (22H), 7.52 (4H), 7.42 (2H)

Example 11

Synthesis of 4,6-bis(4′-cyano-biphenyl-4-yl)-2-(biphenyl-4-yl)-benzoxazole (Compound-105)

[0167] First, 6.0 g of 4-bromo-6-chloro-2-(biphenyl-4-yl)-benzoxazole, 8.0 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.7 g of tris(dibenzylideneacetone)dipalladium(0), 0.7 g of tricyclohexylphosphine, and 10.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 4.5 g (yield: 58%) of a pale yellow powder of 4,6-bis(4′-cyano-biphenyl-4-yl)-2-(biphenyl-4-yl)-benzoxazole (Compound-105).

##STR00021##

[0168] The structure of the obtained pale yellow powder was identified using NMR.

[0169] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0170] δ (ppm)=8.41 (2H), 8.29 (2H), 7.90-7.67 (20H), 7.52 (2H), 7.45 (1H)

Example 12

Synthesis of 6-(4′-cyano-biphenyl-4-yl)-2-(4′-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole (Compound-106)

[0171] First, 14.0 g of 6-chloro-2-(4-chloro-phenyl)-4-phenyl-benzoxazole, 23.3 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 2.0 g of tris(dibenzylideneacetone)dipalladium(0), 2.0 g of tricyclohexylphosphine, and 23.2 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, ethyl acetate and water were added to the system, followed by extraction and separation to obtain an organic layer, and the organic layer was concentrated. The obtained concentrate was purified through column chromatography (carrier: silica gel, eluent: dichloromethane/ethyl acetate) to thereby obtain 4.6 g (yield: 20%) of a pale yellow powder of 6-(4′-cyano-biphenyl-4-yl)-2-(4′-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole (Compound-106).

##STR00022##

[0172] The structure of the obtained pale yellow powder was identified using NMR.

[0173] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0174] δ (ppm)=8.46 (2H), 8.15 (2H), 7.90-7.72 (20H), 7.61 (2H), 7.50 (1H)

Example 13

Synthesis of 4,6-bis(biphenyl-4-yl)-2-(4′-cyano-biphenyl-3-yl)-benzoxazole (Compound-108)

[0175] First, 10.5 g of 4,6-bis(biphenyl-4-yl)-2-(3-chloro-phenyl)-benzoxazole, 3.0 g of 4-cyanophenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 8.3 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 9.6 g (yield: 81%) of a white powder of 4,6-bis(biphenyl-4-yl)-2-(4′-cyano-biphenyl-3-yl)-benzoxazole (Compound-108).

##STR00023##

[0176] The structure of the obtained white powder was identified using NMR.

[0177] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0178] δ (ppm)=8.57 (1H), 8.41 (1H), 8.23 (2H), 7.92 (1H), 7.88-7.65 (17H), 7.52 (4H), 7.42 (2H)

Example 14

Synthesis of 4,6-bis(biphenyl-4-yl)-2-(3′-cyano-biphenyl-3-yl)-benzoxazole (Compound-109)

[0179] First, 9.6 g of 4,6-bis(biphenyl-4-yl)-2-(3-chloro-phenyl)-benzoxazole, 5.3 g of 3-cyanophenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 7.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 2.6 g (yield: 24%) of a white powder of 4,6-bis(biphenyl-4-yl)-2-(3′-cyano-biphenyl-3-yl)-benzoxazole (Compound-109).

##STR00024##

[0180] The structure of the obtained white powder was identified using NMR.

[0181] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0182] δ (ppm)=8.55 (1H), 8.41 (1H), 8.24 (2H), 8.02 (1H), 7.96 (1H), 7.92 (1H), 7.88 (1H), 7.86-7.60 (14H), 7.52 (4H), 7.42 (2H)

Example 15

Synthesis of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(3′-cyano-biphenyl-4-yl)-benzoxazole (Compound-110)

[0183] First, 7.0 g of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(4-chloro-phenyl)-benzoxazole, 1.8 g of 3-cyanophenylboronic acid, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), 0.3 g of tricyclohexylphosphine, and 7.0 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, toluene and water were added to the system, followed by extraction and separation to obtain an organic layer, and the organic layer was concentrated. The obtained concentrate was purified through column chromatography (carrier: silica gel, eluent: toluene/n-heptane) to thereby obtain 5.5 g (yield: 71%) of a pale yellow powder of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(3′-cyano-biphenyl-4-yl)-benzoxazole (Compound-110).

##STR00025##

[0184] The structure of the obtained pale yellow powder was identified using NMR.

[0185] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0186] δ (ppm)=8.51 (2H), 8.33 (2H), 8.13 (1H), 8.06 (1H), 8.04 (1H), 8.01-7.84 (9H), 7.77 (3H), 7.71 (3H), 7.66-7.41 (10H)

Example 16

Synthesis of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(3′-cyano-biphenyl-3-yl)-benzoxazole (Compound-111)

[0187] First, 12.0 g of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(3-chloro-phenyl)-benzoxazole, 3.3 g of 3-cyanophenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 8.0 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from toluene as solvent to thereby obtain 10.0 g (yield: 76%) of a white powder of 4,6-bis(4-naphthalene-1-yl-phenyl)-2-(3′-cyano-biphenyl-3-yl)-benzoxazole (Compound-111).

##STR00026##

[0188] The structure of the obtained white powder was identified using NMR.

[0189] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0190] δ (ppm)=8.58 (1H), 8.45 (1H), 8.32 (2H), 8.13 (1H), 8.05 (1H), 8.04 (2H), 7.98 (3H), 7.95 (2H), 7.91 (3H), 7.81-7.65 (8H), 7.62 (2H), 7.59-7.48 (6H)

Example 17

Synthesis of 4,6-bis(phenanthrene-9-yl)-2-(3′-cyano-biphenyl-4-yl)-benzoxazole (Compound-115)

[0191] First, 10.0 g of 2-(4-chloro-phenyl)-4,6-bis(phenanthrene-9-yl)-benzoxazole, 3.0 g of 3-cyanophenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 7.3 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from toluene as solvent to thereby obtain 8.4 g (yield: 75%) of a white powder of 4,6-bis(phenanthrene-9-yl)-2-(3′-cyano-biphenyl-4-yl)-benzoxazole (Compound-115).

##STR00027##

[0192] The structure of the obtained white powder was identified using NMR.

[0193] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0194] δ (ppm)=8.84 (2H), 8.79 (2H), 8.35 (2H), 8.18 (1H), 8.06 (1H), 8.05 (1H), 7.98 (2H), 7.92 (3H), 7.86 (1H), 7.78 (1H), 7.77-7.65 (9H), 7.62 (2H), 7.58 (1H)

Example 18

Synthesis of 2-(3′-cyano-biphenyl-3-yl)-6-(9,9′-spirobi[9H]fluorene-2-yl)-benzoxazole (Compound-117)

[0195] First, 10.5 g of 2-(3-chloro-phenyl)-6-(9,9′-spirobi[9H]fluorene-2-yl)-benzoxazole, 3.0 g of 3-cyanophenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 8.2 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, ethyl acetate and water were added to the system, followed by extraction and separation to obtain an organic layer, and the organic layer was concentrated. The obtained concentrate was purified through column chromatography (carrier: silica gel, eluent: dichloromethane/n-heptane) to thereby obtain 5.0 g (yield: 48%) of a pale yellow powder of 2-(3′-cyano-biphenyl-3-yl)-6-(9,9′-spirobi[9H]fluorene-2-yl)-benzoxazole (Compound-117).

##STR00028##

[0196] The structure of the obtained pale yellow powder was identified using NMR.

[0197] In .sup.1H-NMR (CDCl.sub.3), the following signals of 26 hydrogens were detected.

[0198] δ (ppm)=8.45 (1H), 8.27 (1H), 7.98 (1H), 7.97 (1H), 7.91 (4H), 7.72 (4H), 7.69 (1H), 7.64 (1H), 7.60 (1H), 7.49 (1H), 7.42 (3H), 7.16 (3H), 7.03 (1H), 6.83 (2H), 6.78 (1H)

Example 19

Synthesis of 6-(9,9-diphenyl-9H-fluorene-3-yl)-2-(3′-cyano-biphenyl-3-yl)-benzoxazole (Compound-118)

[0199] First, 10.5 g of 2-(3-chloro-phenyl)-6-(9,9-diphenyl-9H-fluorene-3-yl)-benzoxazole, 3.0 g of 3-cyanophenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 8.2 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 6.4 g (yield: 54%) of a white powder of 6-(9,9-diphenyl-9H-fluorene-3-yl)-2-(3′-cyano-biphenyl-3-yl)-benzoxazole (Compound-118).

##STR00029##

[0200] The structure of the obtained white powder was identified using NMR.

[0201] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0202] δ (ppm)=8.53 (1H), 8.35 (1H), 8.03 (2H), 7.97 (1H), 7.90 (2H), 7.88 (1H), 7.76 (2H), 7.72 (2H), 7.65 (1H), 7.56 (2H), 7.45 (2H), 7.38-7.22 (11H)

Example 20

Synthesis of 6-(9,9-diphenyl-9H-fluorene-4-yl)-2-(3′-cyano-biphenyl-3-yl)-benzoxazole (Compound-119)

[0203] First, 10.5 g of 2-(3-chloro-phenyl)-6-(9,9-diphenyl-9H-fluorene-4-yl)-benzoxazole, 3.0 g of 3-cyanophenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 8.2 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of toluene/acetone to thereby obtain 6.4 g (yield: 54%) of a white powder of 6-(9,9-diphenyl-9H-fluorene-4-yl)-2-(3′-cyano-biphenyl-3-yl)-benzoxazole (Compound-119).

##STR00030##

[0204] The structure of the obtained white powder was identified using NMR.

[0205] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0206] δ (ppm)=8.55 (1H), 8.38 (1H), 8.03 (1H), 7.98 (1H), 7.94 (1H), 7.79 (2H), 7.74 (1H), 7.72 (1H), 7.65 (1H), 7.58 (1H), 7.50 (1H), 7.42 (1H), 7.35 (2H), 7.32-7.23 (10H), 7.20 (1H), 7.03 (1H), 6.92 (1H)

Example 21

Synthesis of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4,6-diphenyl-benzoxazole (Compound-120)

[0207] First, 8.8 g of 2-(4-chloro-phenyl)-4, 6-diphenyl-benzoxazole, 8.4 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 1.1 g of tris(dibenzylideneacetone)dipalladium(0), 1.3 g of tricyclohexylphosphine, and 14.7 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 11.5 g (yield: 95%) of a pale yellow powder of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4,6-diphenyl-benzoxazole (Compound-120).

##STR00031##

[0208] The structure of the obtained pale yellow powder was identified using NMR.

[0209] In .sup.1H-NMR (CDCl.sub.3), the following signals of 24 hydrogens were detected.

[0210] δ (ppm)=8.41 (2H), 8.16 (2H), 7.89-7.67 (14H), 7.65-7.38 (6H)

Example 22

Synthesis of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-6-(9,9′-spirobi[9H]fluorene-4-yl)-benzoxazole (Compound-123)

[0211] First, 6.5 g of 2-(4-chloro-phenyl)-6-(9,9′-spirobi[9H]fluorene-4-yl)-benzoxazole, 4.0 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), 0.3 g of tricyclohexylphosphine, and 7.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of monochlorobenzene/acetone to thereby obtain 7.5 g (yield: 91%) of a pale yellow powder of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-6-(9,9′-spirobi[9H]fluorene-4-yl)-benzoxazole (Compound-123).

##STR00032##

[0212] The structure of the obtained pale yellow powder was identified using NMR.

[0213] In .sup.1H-NMR (CDCl.sub.3), the following signals of 30 hydrogens were detected.

[0214] δ (ppm)=8.46 (2H), 8.00 (1H), 7.90 (2H), 7.89 (2H), 7.85 (3H), 7.80 (4H), 7.76 (2H), 7.68 (1H), 7.42 (2H), 7.30 (1H), 7.19 (3H), 7.05 (3H), 6.86 (2H), 6.79 (1H), 6.74 (1H)

Example 23

Synthesis of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-3-yl)-4,6-diphenyl-benzoxazole (Compound-127)

[0215] First, 7.1 g of 2-(3-chloro-phenyl)-4,6-diphenyl-benzoxazole, 6.2 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 7.9 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 5.3 g (yield: 54%) of a white powder of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-3-yl)-4,6-diphenyl-benzoxazole (Compound-127).

##STR00033##

[0216] The structure of the obtained white powder was identified using NMR.

[0217] In .sup.1H-NMR (CDCl.sub.3), the following signals of 24 hydrogens were detected.

[0218] δ (ppm)=8.60 (1H), 8.36 (1H), 8.14 (2H), 7.89-7.71 (13H), 7.67 (1H), 7.63-7.40 (6H)

Example 24

Synthesis of 4,6-bis(biphenyl-4-yl)-2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-3-yl)-benzoxazole (Compound-128)

[0219] First, 8.0 g of 4,6-bis(biphenyl-4-yl)-2-(3-chloro-phenyl)-benzoxazole, 4.8 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.4 g of tris(dibenzylideneacetone)dipalladium(0), 0.4 g of tricyclohexylphosphine, and 6.4 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 7.2 g (yield: 71%) of a white powder of 4,6-bis(biphenyl-4-yl)-2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-3-yl)-benzoxazole (Compound-128).

##STR00034##

[0220] The structure of the obtained white powder was identified using NMR.

[0221] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0222] δ (ppm)=8.64 (1H), 8.38 (1H), 8.25 (2H), 7.92 (1H), 7.89-7.81 (8H), 7.81-7.64 (13H), 7.52 (4H), 7.42 (2H)

Example 25

Synthesis of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-3-yl)-4,6-di(naphthalene-1-yl)-benzoxazole (Compound-130)

[0223] First, 9.1 g of 2-(3-chloro-phenyl)-4,6-di(naphthalene-1-yl)-benzoxazole, 6.1 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 8.0 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 1.8 g (yield: 15%) of a white powder of 2-(4″-cyano-[1,1′;4′,1″ ]terphenyl-3-yl)-4,6-di(naphthalene-1-yl)-benzoxazole (Compound-130).

##STR00035##

[0224] The structure of the obtained white powder was identified using NMR.

[0225] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0226] δ (ppm)=8.53 (1H), 8.28 (1H), 8.15 (1H), 8.03 (1H), 7.97 (3H), 7.94 (1H), 7.86 (1H), 7.84-7.73 (8H), 7.68 (4H), 7.65-7.42 (7H) Example 26

Synthesis of 2-(4′″-cyano-[1,1′;4′,1″;4″,1′″]quaterphenyl-4-yl)-6-(phenanthrene-9-yl)-benzoxazole (Compound-136)

[0227] First, 10.0 g of 2-(4-chloro-phenyl)-6-(phenanthrene-9-yl)-benzoxazole, 11.3 g of 4-(4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-[1,1′;4′,1″ ]terphenyl-4″-carbonitrile, 0.7 g of tris(dibenzylideneacetone)dipalladium(0), 0.7 g of tricyclohexylphosphine, and 10.5 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 13.1 g (yield: 85%) of a yellow powder of 6-(phenanthrene-9-yl)-2-(4′″-cyano-[1,1′;4′,1″;4″,1′″]quaterphenyl-4-yl)-benzoxazole (Compound-136).

##STR00036##

[0228] The structure of the obtained yellow powder was identified using NMR.

[0229] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0230] δ (ppm)=8.84 (1H), 8.79 (1H), 8.44 (2H), 7.97 (2H), 7.94 (1H), 7.88 (2H), 7.86-7.77 (12H), 7.75 (3H), 7.67 (2H), 7.60 (2H)

Example 27

Synthesis of 2-(4′″-cyano-[1,1′;4′,1″;4″,1′″]quaterphenyl-4-yl)-6-(phenanthrene-9-yl)-4-phenyl-benzoxazole (Compound-137)

[0231] First, 10.0 g of 2-(4-chloro-phenyl)-6-(phenanthrene-9-yl)-4-phenyl-benzoxazole, 9.5 g of 4-(4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-[1,1′;4′,1″ ]terphenyl-4″-carbonitrile, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 8.8 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 11.9 g (yield: 82%) of a yellow powder of 2-(4′″-cyano-[1,1′;4′,1″;4″,1′″]quaterphenyl-4-yl)-6-(phenanthrene-9-yl)-4-phenyl-benzoxazole (Compound-137).

##STR00037##

[0232] The structure of the obtained yellow powder was identified using NMR.

[0233] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0234] δ (ppm)=8.85 (1H), 8.80 (1H), 8.48 (2H), 8.19 (2H), 8.07 (1H), 7.96 (1H), 7.86 (4H), 7.81 (6H), 7.78 (5H), 7.73 (4H), 7.69 (1H), 7.63 (1H), 7.58 (2H), 7.46 (1H)

Example 28

Synthesis of 2-[4-{4-(4′-cyano-biphenyl-4-yl)-naphthalene-1-yl}-phenyl]-6-(phenanthrene-9-yl)-benzoxazole (Compound-138)

[0235] First, 8.0 g of 2-(4-chloro-phenyl)-6-(phenanthrene-9-yl)-benzoxazole, 10.2 g of 4′-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-naphthalene-1-yl}1-biphenyl-4-carbonitrile, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 12.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 11.3 g (yield: 85%) of a yellow powder of 2-[4-{4-(4′-cyano-biphenyl-4-yl)-naphthalene-1-yl}-phenyl]-6-(phenanthrene-9-yl)-benzoxazole (Compound-138).

##STR00038##

[0236] The structure of the obtained yellow powder was identified using NMR.

[0237] In .sup.1H-NMR (CDCl.sub.3), the following signals of 30 hydrogens were detected.

[0238] δ (ppm)=8.85 (1H), 8.79 (1H), 8.50 (2H), 8.07 (2H), 8.01 (1H), 7.97 (2H), 7.87-7.75 (10H), 7.72 (4H), 7.67 (1H), 7.62 (2H), 7.59 (2H), 7.55 (2H)

Example 29

Synthesis of 4-(biphenyl-4-yl)-6-(4-cyano-phenyl)-2-([1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole (Compound-143)

[0239] First, 6.0 g of 6-chloro-4-(biphenyl-4-yl)-6-([1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole, 2.0 g of 4-cyanophenylboronic acid, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), 0.3 g of tricyclohexylphosphine, and 4.8 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 3.5 g (yield: 52%) of a pale yellow powder of 4-(biphenyl-4-yl)-6-(4-cyano-phenyl)-2-([1,1′;4′,1″ ]terphenyl-4-yl)-benzoxazole (Compound-143).

##STR00039##

[0240] The structure of the obtained pale yellow powder was identified using NMR.

[0241] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0242] δ (ppm)=8.44 (2H), 8.24 (2H), 7.89-7.65 (18H), 7.52 (4H), 7.42 (2H)

Example 30

Synthesis of 6-(4-cyano-phenyl)-4-(phenanthrene-9-yl)-2-{4-(phenanthrene-9-yl)-phenyl}-benzoxazole (Compound-144)

[0243] First, 15.7 g of 6-chloro-4-(phenanthrene-9-yl)-2-{4-(phenanthrene-9-yl)-phenyl}-benzoxazole, 4.2 g of 4-cyanophenylboronic acid, 0.7 g of tris(dibenzylideneacetone)dipalladium(0), 0.8 g of tricyclohexylphosphine, and 11.5 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 12.6 g (yield: 72%) of a white powder of 6-(4-cyano-phenyl)-4-(phenanthrene-9-yl)-2-{4-(phenanthrene-9-yl)-phenyl}-benzoxazole (Compound-144).

##STR00040##

[0244] The structure of the obtained white powder was identified using NMR.

[0245] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0246] δ (ppm)=8.87 (1H), 8.81 (2H), 8.75 (1H), 8.37 (2H), 8.00 (1H), 7.99-7.60 (19H), 7.56 (2H)

Example 31

Synthesis of 2-(biphenyl-4-yl)-6-(4-cyano-phenyl)-4-(phenanthrene-9-yl)-benzoxazole (Compound-147)

[0247] First, 10.5 g of 2-(biphenyl-4-yl)-6-chloro-4-(phenanthrene-9-yl)-benzoxazole, 3.8 g of 4-cyanophenylboronic acid, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 9.2 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from toluene as solvent to thereby obtain 7.2 g (yield: 60%) of a white powder of 2-(biphenyl-4-yl)-6-(4-cyano-phenyl)-4-(phenanthrene-9-yl)-benzoxazole (Compound-147).

##STR00041##

[0248] The structure of the obtained white powder was identified using NMR.

[0249] In .sup.1H-NMR (CDCl.sub.3), the following signals of 24 hydrogens were detected.

[0250] δ (ppm)=8.86 (1H), 8.81 (1H), 8.28 (2H), 7.97 (2H), 7.93 (1H), 7.91-7.61 (13H), 7.54 (1H), 7.49 (2H), 7.41 (1H)

Example 32

Synthesis of 2-(biphenyl-4-yl)-6-(4′-cyano-biphenyl-4-yl)-4-(phenanthrene-9-yl)-benzoxazole (Compound-148)

[0251] First, 10.5 g of 2-(biphenyl-4-yl)-6-chloro-4-(phenanthrene-9-yl)-benzoxazole, 8.0 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 9.2 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 11.4 g (yield: 84%) of a white powder of 2-(biphenyl-4-yl)-6-(4′-cyano-biphenyl-4-yl)-4-(phenanthrene-9-yl)-benzoxazole (Compound-148).

##STR00042##

[0252] The structure of the obtained white powder was identified using NMR.

[0253] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0254] δ (ppm)=8.87 (1H), 8.82 (1H), 8.30 (2H), 8.00 (3H), 7.94 (1H), 7.88 (2H), 7.84 (1H), 7.78 (4H), 7.77-7.63 (9H), 7.55 (1H), 7.49 (2H), 7.41 (1H)

Example 33

Synthesis of 6-(4′-cyano-biphenyl-4-yl)-2-{4-(phenanthrene-9-yl)-phenyl}-4-phenyl-benzoxazole (Compound-149)

[0255] First, 13.0 g of 2-(4-chloro-phenyl)-6-(4′-cyano-biphenyl-4-yl)-4-phenyl-benzoxazole, 6.0 g of 9-phenanthreneboronic acid, 0.7 g of tris(dibenzylideneacetone)dipalladium(0), 0.8 g of tricyclohexylphosphine, and 11.4 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 12.0 g (yield: 71%) of a white powder of 6-(4′-cyano-biphenyl-4-yl)-2-{4-(phenanthrene-9-yl)-phenyl}-4-phenyl-benzoxazole (Compound-149).

##STR00043##

[0256] The structure of the obtained white powder was identified using NMR.

[0257] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0258] δ (ppm)=8.82 (1H), 8.78 (1H), 8.50 (2H), 8.18 (2H), 7.98 (1H), 7.95 (1H), 7.88 (4H), 7.81-7.71 (11H), 7.68 (1H), 7.64 (1H), 7.60 (2H), 7.50 (1H)

Example 34

Synthesis of 6-(4′-cyano-biphenyl-4-yl)-2-{4-(9,9′-spirobi[9H]fluorene-4-yl)-phenyl}-benzoxazole (Compound-150)

[0259] First, 11.3 g of 2-(4-chloro-phenyl)-6-(4′-cyano-biphenyl-4-yl)-benzoxazole, 11.0 g of 9,9′-spirobi[9H]fluorene-4-yl-boronic acid, 0.8 g of tris(dibenzylideneacetone)dipalladium(0), 0.8 g of tricyclohexylphosphine, and 11.8 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 12.6 g (yield: 66%) of a pale yellow powder of 6-(4′-cyano-biphenyl-4-yl)-2-{4-(9,9′-spirobi[9H]fluorene-4-yl)-phenyl}-benzoxazole (Compound-150).

##STR00044##

[0260] The structure of the obtained pale yellow powder was identified using NMR.

[0261] In .sup.1H-NMR (CDCl.sub.3), the following signals of 30 hydrogens were detected.

[0262] δ (ppm)=8.51 (2H), 7.94 (1H), 7.92 (1H), 7.91 (1H), 7.88 (2H), 7.84 (3H), 7.80 (2H), 7.79 (3H), 7.75 (1H), 7.73 (1H), 7.42 (2H), 7.27 (1H), 7.22-7.14 (4H), 7.07 (2H), 6.85 (2H), 6.79 (1H), 6.74 (1H)

Example 35

Synthesis of 6-(4′-cyano-biphenyl-4-yl)-4-phenyl-2-{4-(9,9′-spirobi[9H]fluorene-4-yl)-phenyl}-benzoxazole (Compound-151)

[0263] First, 12.1 g of 2-(4-chloro-phenyl)-6-(4′-cyano-biphenyl-4-yl)-4-phenyl-benzoxazole, 6.0 g of 9,9′-spirobi[9H]fluorene-4-yl-boronic acid, 0.7 g of tris(dibenzylideneacetone)dipalladium(0), 0.7 g of tricyclohexylphosphine, and 10.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 8.2 g (yield: 43%) of a pale yellow powder of 6-(4′-cyano-biphenyl-4-yl)-4-phenyl-2-{4-(9,9′-spirobi[9H]fluorene-4-yl)-phenyl}-benzoxazole (Compound-151).

##STR00045##

[0264] The structure of the obtained pale yellow powder was identified using NMR.

[0265] In .sup.1H-NMR (CDCl.sub.3), the following signals of 34 hydrogens were detected.

[0266] δ (ppm)=8.55 (2H), 8.19 (2H), 7.94-7.85 (7H), 7.85-7.74 (6H), 7.63 (2H), 7.51 (1H), 7.42 (2H), 7.27 (1H), 7.28 (1H), 7.18 (4H), 7.07 (2H), 6.86 (2H), 6.79 (1H), 6.75 (1H)

Example 36

Synthesis of 2-(biphenyl-4-yl)-6-{4-(4-cyano-phenyl)-naphthalene-1-yl}-4-phenyl-benzoxazole (Compound-154)

[0267] First, 13.2 g of 2-(biphenyl-4-yl)-6-bromo-4-phenyl-benzoxazole, 11.5 g of 4-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-naphthalene-1-yl}-phenyl-carbonitrile, 0.7 g of tetrakis(triphenylphosphine)dipalladium (0), and 7.3 g of potassium carbonate were placed in a reaction vessel, and stirred in a mixed solvent of toluene/ethanol/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of tetrahydrofuran/acetone to thereby obtain 15.8 g (yield: 89%) of a white powder of 2-(biphenyl-4-yl)-6-{4-(4-cyano-phenyl)-naphthalene-1-yl}-4-phenyl-benzoxazole (Compound-154).

##STR00046##

[0268] The structure of the obtained white powder was identified using NMR.

[0269] In .sup.1H-NMR (CDCl.sub.3), the following signals of 26 hydrogens were detected.

[0270] δ (ppm)=8.46 (2H), 8.18 (2H), 8.14 (1H), 7.91 (1H), 7.86 (2H), 7.81 (2H), 7.76 (2H), 7.72 (4H), 7.65 (1H), 7.62-7.40 (9H)

Example 37

Synthesis of 6-[4-{4-(4′-cyano-biphenyl-4-yl)-naphthalene-1-yl}-phenyl]-2,4-diphenyl-benzoxazole (Compound-155)

[0271] First, 4.0 g of 6-chloro-2,4-diphenyl-benzoxazole, 5.9 g of 4′-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-naphthalene-1-yl}-biphenyl-4-carbonitrile, 0.4 g of tris(dibenzylideneacetone)dipalladium(0), 0.4 g of tricyclohexylphosphine, and 5.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 3.2 g (yield: 43%) of a white powder of 6-[4-{4-(4′-cyano-biphenyl-4-yl)-naphthalene-1-yl}-phenyl]-2,4-diphenyl-benzoxazole (Compound-155).

##STR00047##

[0272] The structure of the obtained white powder was identified using NMR.

[0273] In .sup.1H-NMR (CDCl.sub.3), the following signals of 26 hydrogens were detected.

[0274] δ (ppm)=8.40 (1H), 8.38 (1H), 8.17 (2H), 8.13 (1H), 8.07 (1H), 7.83 (5H), 7.77 (3H), 7.72 (2H), 7.67-7.51 (9H), 7.47 (1H)

Example 38

Synthesis of 2-(biphenyl-4-yl)-6-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole (Compound-156)

[0275] First, 13.2 g of 2-(biphenyl-4-yl)-6-bromo-4-phenyl-benzoxazole, 12.4 g of 4-(4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-[1,1′;4′,1″ ]terphenyl-4″-carbonitrile, 0.7 g of tetrakis(triphenylphosphine)dipalladium (0), and 7.3 g of potassium carbonate were placed in a reaction vessel, and stirred in a mixed solvent of toluene/ethanol/H.sub.2O under refluxed overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 7.2 g (yield: 39%) of a white powder of 2-(biphenyl-4-yl)-6-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole (Compound-156).

##STR00048##

[0276] The structure of the obtained white powder was identified using NMR.

[0277] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0278] δ (ppm)=8.42 (2H), 8.16 (2H), 7.86 (3H), 7.84 (2H), 7.81 (4H), 7.78 (5H), 7.74 (2H), 7.71 (2H), 7.60 (2H), 7.52 (2H), 7.49 (1H), 7.45 (1H)

Example 39

Synthesis of 2-{4-(phenanthrene-9-yl)-phenyl}-6-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole (Compound-157)

[0279] First, 12.8 g of 2-(4-chloro-phenyl)-6-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole, 5.3 g of 9-phenanthreneboronic acid, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 9.7 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 5.3 g (yield: 33%) of a white powder of 2-{4-(phenanthrene-9-yl)-phenyl}-6-(4″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole (Compound-157).

##STR00049##

[0280] The structure of the obtained white powder was identified using NMR.

[0281] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0282] δ (ppm)=8.84 (1H), 8.78 (1H), 8.50 (2H), 8.19 (2H), 7.97 (2H), 7.91-7.66 (20H), 7.61 (3H), 7.49 (1H)

Example 40

Synthesis of 2-(biphenyl-4-yl)-6-(3″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole (Compound-158)

[0283] First, 11.0 g of 2-(biphenyl-4-yl)-6-chloro-4-phenyl-benzoxazole, 11.5 g of 4-(4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-[1,1′;4′,1″ ]terphenyl-3″-carbonitrile, 0.8 g of tris(dibenzylideneacetone)dipalladium(0), 0.8 g of tricyclohexylphosphine, and 12.2 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 15.4 g (yield: 89%) of a pale yellow powder of 2-(biphenyl-4-yl)-6-(3″-cyano-[1,1′;4′,1″ ]terphenyl-4-yl)-4-phenyl-benzoxazole (Compound-158).

##STR00050##

[0284] The structure of the obtained pale yellow powder was identified using NMR.

[0285] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0286] δ (ppm)=8.42 (2H), 8.17 (2H), 7.96 (1H), 7.90 (1H), 7.88-7.76 (10H), 7.74-7.66 (5H), 7.60 (3H), 7.54 (2H), 7.45 (2H)

Example 41

Synthesis of 2-(biphenyl-4-yl)-6-{4-(4′-cyano-biphenyl-4-yl)-naphthalene-1-yl}-4-phenyl-benzoxazole (Compound-159)

[0287] First, 13.2 g of 2-(biphenyl-4-yl)-6-bromo-4-phenyl-benzoxazole, 14.0 g of 4′-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-naphthalene-1-yl}-biphenyl-4-carbonitrile, 0.7 g of tetrakis(triphenylphosphine)dipalladium (0), and 7.3 g of potassium carbonate were placed in a reaction vessel, and stirred in a mixed solvent of toluene/ethanol/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of tetrahydrofuran/acetone to thereby obtain 13.0 g (yield: 65%) of a white powder of 2-(biphenyl-4-yl)-6-{4-(4′-cyano-biphenyl-4-yl)-naphthalene-1-yl}-4-phenyl-benzoxazole (Compound-159).

##STR00051##

[0288] The structure of the obtained white powder was identified using NMR.

[0289] In .sup.1H-NMR (CDCl.sub.3), the following signals of 30 hydrogens were detected.

[0290] δ (ppm)=8.46 (2H), 8.19 (2H), 8.15 (1H), 8.08 (1H), 7.87-7.77 (10H), 7.72 (4H), 7.66 (1H), 7.62-7.41 (9H)

Example 42

Synthesis of 2-(biphenyl-4-yl)-6-{2-(4′-cyano-biphenyl-4-yl)-naphthalene-6-yl}-4-phenyl-benzoxazole (Compound-160)

[0291] First, 13.2 g of 2-(biphenyl-4-yl)-6-chloro-4-phenyl-benzoxazole, 15.7 g of 4′-{2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-naphthalene-6-yl}-biphenyl-4-carbonitrile, 0.9 g of tris(dibenzylideneacetone)dipalladium(0), 1.0 g of tricyclohexylphosphine, and 14.7 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 17.0 g (yield: 72%) of a pale yellow powder of 2-(biphenyl-4-yl)-6-{2-(4′-cyano-biphenyl-4-yl)-naphthalene-6-yl}-4-phenyl-benzoxazole (Compound-160).

##STR00052##

[0292] The structure of the obtained pale yellow powder was identified using NMR.

[0293] In .sup.1H-NMR (CDCl.sub.3), the following signals of 30 hydrogens were detected.

[0294] δ (ppm)=8.43 (2H), 8.22 (2H), 8.18 (2H), 8.08 (2H), 7.97 (2H), 7.93 (3H), 7.88 (1H), 7.85-7.77 (7H), 7.75 (2H), 7.70 (1H), 7.61 (2H), 7.52 (3H), 7.45 (1H) Example 43

Synthesis of 2-(biphenyl-4-yl)-6-{2-(4′-cyano-biphenyl-4-yl)-naphthalene-7-yl}-4-phenyl-benzoxazole (Compound-161)

[0295] First, 13.2 g of 2-(biphenyl-4-yl)-6-chloro-4-phenyl-benzoxazole, 15.7 g of 4′-{2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-naphthalene-7-yl}-biphenyl-4-carbonitrile, 0.9 g of tris(dibenzylideneacetone)dipalladium(0), 1.0 g of tricyclohexylphosphine, and 14.7 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 17.3 g (yield: 77%) of a pale yellow powder of 2-(biphenyl-4-yl)-6-{2-(4′-cyano-biphenyl-4-yl)-naphthalene-7-yl}-4-phenyl-benzoxazole (Compound-161).

##STR00053##

[0296] The structure of the obtained pale yellow powder was identified using NMR.

[0297] In .sup.1H-NMR (CDCl.sub.3), the following signals of 30 hydrogens were detected.

[0298] δ (ppm)=8.42 (2H), 8.23 (2H), 8.19 (2H), 8.03 (2H), 7.94 (2H), 7.92 (3H), 7.84 (2H), 7.82-7.76 (6H), 7.73 (2H), 7.70 (1H), 7.61 (2H), 7.52 (2H), 7.51 (1H), 7.45 (1H) Example 44

Synthesis of 2-(biphenyl-4-yl)-4-(4-cyano-phenyl)-6-(phenanthrene-9-yl)-benzoxazole (Compound-164)

[0299] First, 9.4 g of 2-(4-chloro-phenyl)-4-(4-cyano-phenyl)-6-(phenanthrene-9-yl)-benzoxazole, 2.4 g of phenylboronic acid, 0.5 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 7.9 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of toluene/acetone to thereby obtain 5.3 g (yield: 51%) of a white powder of 2-(biphenyl-4-yl)-4-(4-cyano-phenyl)-6-(phenanthrene-9-yl)-benzoxazole (Compound-164).

##STR00054##

[0300] The structure of the obtained white powder was identified using NMR.

[0301] In .sup.1H-NMR (CDCl.sub.3), the following signals of 24 hydrogens were detected.

[0302] δ (ppm)=8.86 (1H), 8.80 (1H), 8.45 (2H), 8.33 (2H), 8.01 (1H), 7.96 (1H), 7.90-7.65 (12H), 7.61 (1H), 7.54 (2H), 7.46 (1H)

Example 45

Synthesis of 2-(biphenyl-4-yl)-4-(3-cyano-phenyl)-6-(phenanthrene-9-yl)-benzoxazole (Compound-165)

[0303] First, 9.1 g of 2-(biphenyl-4-yl)-6-chloro-4-(3-cyano-phenyl)-benzoxazole, 6.0 g of 9-phenanthreneboronic acid, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 9.5 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 10.4 g (yield: 85%) of a white powder of 2-(biphenyl-4-yl)-4-(3-cyano-phenyl)-6-(phenanthrene-9-yl)-benzoxazole (Compound-165).

##STR00055##

[0304] The structure of the obtained white powder was identified using NMR.

[0305] In .sup.1H-NMR (CDCl.sub.3), the following signals of 24 hydrogens were detected.

[0306] δ (ppm)=8.86 (1H), 8.79 (1H), 8.59 (1H), 8.45 (2H), 8.38 (1H), 8.02 (1H), 7.97 (1H), 7.84 (2H), 7.83 (2H), 7.79-7.53 (9H), 7.54 (2H), 7.45 (1H)

Example 46

Synthesis of 2-(biphenyl-4-yl)-4-(4-cyano-phenyl)-6-{4-(phenanthrene-9-yl)-phenyl}-benzoxazole (Compound-166)

[0307] First, 9.0 g of 2-(biphenyl-4-yl)-6-chloro-4-(4-cyano-phenyl)-benzoxazole, 7.9 g of 4-(phenanthrene-9-yl)phenylboronic acid, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 9.4 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 11.7 g (yield: 85%) of a white powder of 2-(biphenyl-4-yl)-4-(4-cyano-phenyl)-6-{4-(phenanthrene-9-yl)-phenyl}-benzoxazole (Compound-166).

##STR00056##

[0308] The structure of the obtained white powder was identified using NMR.

[0309] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0310] δ (ppm)=8.85 (1H), 8.78 (1H), 8.44 (2H), 8.34 (2H) 8.05 (1H), 7.96 (3H), 7.89 (4H), 7.83 (2H), 7.79 (1H), 7.77-7.68 (6H), 7.66 (1H), 7.62 (1H), 7.53 (2H), 7.45 (1H)

Example 47

Synthesis of 2-(biphenyl-4-yl)-4-(3-cyano-phenyl)-6-{4-(phenanthrene-9-yl)-phenyl}-benzoxazole (Compound-167)

[0311] First, 9.1 g of 2-(biphenyl-4-yl)-6-chloro-4-(3-cyano-phenyl)-benzoxazole, 8.0 g of 4-(phenanthrene-9-yl)phenylboronic acid, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.6 g of tricyclohexylphosphine, and 9.5 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene solvent to thereby obtain 11.9 g (yield: 85%) of a white powder of 2-(biphenyl-4-yl)-4-(3-cyano-phenyl)-6-{4-(phenanthrene-9-yl)-phenyl}-benzoxazole (Compound-167).

##STR00057##

[0312] The structure of the obtained white powder was identified using NMR.

[0313] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0314] δ (ppm)=8.84 (1H), 8.78 (1H), 8.56 (1H), 8.43 (3H), 8.05 (1H), 7.97 (1H), 7.96 (1H), 7.90 (2H), 7.85 (2H), 7.82-7.68 (10H), 7.63 (2H), 7.53 (2H), 7.45 (1H)

Example 48

Synthesis of 2-(biphenyl-4-yl)-4-(4′-cyano-biphenyl-4-yl)-6-(phenanthrene-9-yl)-benzoxazole (Compound-168)

[0315] First, 9.4 g of 2-(4-chloro-phenyl)-4-(4′-cyano-biphenyl-4-yl)-6-(phenanthrene-9-yl)-benzoxazole, 2.1 g of phenylboronic acid, 0.4 g of tris(dibenzylideneacetone)dipalladium(0), 0.5 g of tricyclohexylphosphine, and 6.8 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent thereby obtain 5.2 g (yield: 51%) of a white powder of 2-(biphenyl-4-yl)-4-(4′-cyano-biphenyl-4-yl)-6-(phenanthrene-9-yl)-benzoxazole (Compound-168).

##STR00058##

[0316] The structure of the obtained white powder was identified using NMR.

[0317] In .sup.1H-NMR (CDCl.sub.3), the following signals of 28 hydrogens were detected.

[0318] δ (ppm)=8.86 (1H), 8.80 (1H), 8.46 (2H), 8.32 (2H), 8.07 (1H), 7.96 (1H), 7.88-7.77 (11H), 7.77-7.65 (5H), 7.61 (1H), 7.53 (2H), 7.45 (1H).

Example 49

Synthesis of 2-(biphenyl-4-yl)-6-(4′-cyano-biphenyl-4-yl)-4-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-173)

[0319] First, 7.5 g of 2-(biphenyl-4-yl)-6-chloro-4-{4-(pyridine-3-yl)-phenyl}-benzoxazole, 5.5 g of 4′-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)biphenyl-4-carbonitrile, 0.8 g of tris(dibenzylideneacetone)dipalladium(0), 0.9 g of tricyclohexylphosphine, and 10.4 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of N-methylpyrrolidone/acetone to thereby obtain 6.5 g (yield: 66%) of a pale yellow powder of 2-(biphenyl-4-yl)-6-(4′-cyano-biphenyl-4-yl)-4-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-173).

##STR00059##

[0320] The structure of the obtained pale yellow powder was identified using NMR.

[0321] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0322] δ (ppm)=9.00 (1H), 8.67 (1H), 8.43 (2H), 8.29 (2H), 8.01 (1H), 7.92-7.73 (14H), 7.72 (2H), 7.53 (2H), 7.44 (2H)

Example 50

Synthesis of 6-(4′-cyano-biphenyl-4-yl)-4-phenyl-2-{4′-(pyridine-3-yl)-biphenyl-4-yl}-benzoxazole (Compound-175)

[0323] First, 16.3 g of 2-(4-chloro-phenyl)-6-(4′-cyano-biphenyl-4-yl)-4-phenyl-benzoxazole, 7.1 g of 4-(pyridine-3-yl)phenylboronic acid, 0.6 g of tris(dibenzylideneacetone)dipalladium(0), 0.4 g of tricyclohexylphosphine, and 12.2 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 19.4 g (yield: 96%) of a pale yellow powder of 6-(4′-cyano-biphenyl-4-yl)-4-phenyl-2-{4′-(pyridine-3-yl)-biphenyl-4-yl}-benzoxazole (Compound-175).

##STR00060##

[0324] The structure of the obtained pale yellow powder was identified using NMR.

[0325] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0326] δ (ppm)=8.95 (1H), 8.66 (1H), 8.44 (2H), 8.15 (2H), 7.92 (1H), 7.89-7.70 (16H), 7.61 (2H), 7.49 (1H), 7.43 (1H)

Example 51

Synthesis of 2-(biphenyl-4-yl)-4-(4′-cyano-biphenyl-4-yl)-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-179)

[0327] First, 11.8 g of 2-(biphenyl-4-yl)-6-chloro-4-(4′-cyano-biphenyl-4-yl)-benzoxazole, 5.1 g of 4-(pyridine-3-yl)phenylboronic acid, 0.7 g of tris(dibenzylideneacetone)dipalladium(0), 0.7 g of tricyclohexylphosphine, and 10.3 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of monochlorobenzene/acetone to thereby obtain 10.5 g (yield: 72%) of a pale yellow powder of 2-(biphenyl-4-yl)-4-(4′-cyano-biphenyl-4-yl)-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-179).

##STR00061##

[0328] The structure of the obtained pale yellow powder was identified using NMR.

[0329] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0330] δ (ppm)=8.97 (1H), 8.66 (1H), 8.41 (2H), 8.28 (2H), 7.97 (1H), 7.91-7.66 (16H), 7.52 (2H), 7.44 (2H)

Example 52

Synthesis of 2-(biphenyl-4-yl)-4-(4′-cyano-biphenyl-3-yl)-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-180)

[0331] First, 5.0 g of 2-(biphenyl-4-yl)-6-chloro-4-(4′-cyano-biphenyl-3-yl)-benzoxazole, 2.3 g of 4-(pyridine-3-yl)phenylboronic acid, 0.2 g of tris(dibenzylideneacetone)dipalladium(0), 0.3 g of tricyclohexylphosphine, and 6.6 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from 1,2-dichlorobenzene as solvent to thereby obtain 5.4 g (yield: 87%) of a pale yellow powder of 2-(biphenyl-4-yl)-4-(4′-cyano-biphenyl-3-yl)-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-180).

##STR00062##

[0332] The structure of the obtained pale yellow powder was identified using NMR.

[0333] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0334] δ (ppm)=8.96 (1H), 8.67 (1H), 8.41 (1H), 8.39 (2H), 8.19 (1H), 7.98 (1H), 7.92-7.74 (11H), 7.71 (5H), 7.53 (2H), 7.44 (2H)

Example 53

Synthesis of 2-(biphenyl-4-yl)-4-(3′-cyano-biphenyl-4-yl)-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-181)

[0335] First, 6.0 g of 2-(biphenyl-4-yl)-6-chloro-4-(3′-cyano-biphenyl-4-yl)-benzoxazole, 3.0 g of 4-(pyridine-3-yl)phenylboronic acid, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), 0.4 g of tricyclohexylphosphine, and 7.9 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of monochlorobenzene/acetone to thereby obtain 5.2 g (yield: 70%) of a pale yellow powder of 2-(biphenyl-4-yl)-4-(3′-cyano-biphenyl-4-yl)-6-{4-(pyridine-3-yl)-phenyl}-benzoxazole (Compound-181).

##STR00063##

[0336] The structure of the obtained pale yellow powder was identified using NMR.

[0337] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0338] δ (ppm)=8.92 (1H), 8.67 (1H), 8.43 (2H), 8.29 (2H), 8.00 (1H), 7.95 (2H), 7.88 (3H), 7.84-7.73 (6H), 7.70 (3H), 7.64 (2H), 7.53 (2H), 7.45 (2H)

Example 54

Synthesis of 2-(biphenyl-4-yl)-4-(4′-cyano-biphenyl-4-yl)-6-{4-(pyridine-2-yl)-phenyl}-benzoxazole (Compound-182)

[0339] First, 6.0 g of 2-(biphenyl-4-yl)-6-chloro-4-(4′-cyano-biphenyl-4-yl)-benzoxazole, 4.2 g of 2-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-phenyl}-pyridine, 0.3 g of tris(dibenzylideneacetone)dipalladium(0), 0.4 g of tricyclohexylphosphine, and 7.9 g of tripotassium phosphate were placed in a reaction vessel, and stirred in a mixed solvent of 1,4-dioxane/H.sub.2O under reflux overnight. After allowing to cool, water was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through crystallization from a mixed solvent of monochlorobenzene/acetone to thereby obtain 5.4 g (yield: 72%) of a pale yellow powder of 2-(biphenyl-4-yl)-4-(4′-cyano-biphenyl-4-yl)-6-{4-(pyridine-2-yl)-phenyl}-benzoxazole (Compound-182).

##STR00064##

[0340] The structure of the obtained pale yellow powder was identified using NMR.

[0341] In .sup.1H-NMR (CDCl.sub.3), the following signals of 27 hydrogens were detected.

[0342] δ (ppm)=8.77 (1H), 8.42 (2H), 8.30 (2H), 8.18 (2H), 7.92-7.73 (13H), 7.70 (3H), 7.52 (2H), 7.45 (1H), 7.31 (1H)

Example 55

Synthesis of 2-[4-{7-(4′-cyano-biphenyl-4-yl)-9,9-diphenyl-9H-fluorene-2-yl}-phenyl]-benzoxazole (Compound-201)

[0343] First, 2.8 g of 2-{4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolane-2-yl)-phenyl}-benzoxazole, 4.5 g of 4′-(7-bromo-9,9-diphenyl-9H-fluorene-2-yl)-biphenyl-4-carbonitrile, 0.5 g of tetrakis(triphenylphosphine)dipalladium (0), and 1.6 g of potassium carbonate were placed in a reaction vessel, and stirred in a mixed solvent of toluene/ethanol/H.sub.2O under reflux overnight. After allowing to cool, methanol was added to the system for dispersing and washing, and the resulting system was filtered to obtain a crude product. The obtained crude product was purified through recrystallization from monochlorobenzene as solvent to thereby obtain 5.0 g (yield: 93%) of a yellow powder of 2-[4-{7-(4′-cyano-biphenyl-4-yl)-9,9-diphenyl-9H-fluorene-2-yl}-phenyl]-benzoxazole (Compound-201).

##STR00065##

[0344] The structure of the obtained yellow powder was identified using NMR.

[0345] In .sup.1H-NMR (CDCl.sub.3), the following signals of 32 hydrogens were detected.

[0346] δ (ppm)=8.33 (2H), 7.93 (2H), 7.84-7.59 (16H), 7.44-7.23 (12H)

Example 56

[0347] The melting point and the glass transition point of each of the compounds having a benzazole ring structure obtained in Examples 1 to 55 above were measured using a high-sensitivity differential scanning calorimeter (DSC3100SA manufactured by Bruker AXS K.K.). Table 1 shows the results.

TABLE-US-00001 TABLE 1 Compound Melting point Glass transition point Compound of Ex. 1  —° C. 142° C. Compound of Ex. 2 288° C. 169° C. Compound of Ex. 3 315° C. 135° C. Compound of Ex. 4 253° C. 137° C. Compound of Ex. 5 282° C. 150° C. Compound of Ex. 6 252° C. 118° C. Compound of Ex. 7 329° C.  —° C. Compound of Ex. 8 276° C.  —° C. Compound of Ex. 9 341° C.  —° C. Compound of Ex. 10 283° C. 138° C. Compound of Ex. 11  —° C. 143° C. Compound of Ex. 12 361° C.  —° C. Compound of Ex. 13 243° C. 127° C. Compound of Ex. 14 218° C. 102° C. Compound of Ex. 15  —° C. 130° C. Compound of Ex. 16  —° C. 113° C. Compound of Ex. 17  —° C. 156° C. Compound of Ex. 18 278° C. 131° C. Compound of Ex. 19 263° C. 123° C. Compound of Ex. 20 243° C. 124° C. Compound of Ex. 21 234° C. 100° C. Compound of Ex. 22 321° C. 153° C. Compound of Ex. 23 244° C.  96° C. Compound of Ex. 24 292° C. 127° C. Compound of Ex. 25 259° C. 132° C. Compound of Ex. 26 302° C.  —° C. Compound of Ex. 27 308° C. 146° C. Compound of Ex. 28 250° C. 121° C. Compound of Ex. 29 236° C. 125° C. Compound of Ex. 30  —° C. 170° C. Compound of Ex. 31 253° C. 143° C. Compound of Ex. 32 278° C. 155° C. Compound of Ex. 33 265° C. 138° C. Compound of Ex. 34 288° C. 154° C. Compound of Ex. 35 295° C. 182° C. Compound of Ex. 36 254° C. 120° C. Compound of Ex. 37 274° C. 116° C. Compound of Ex. 38 282° C.  —° C. Compound of Ex. 39 274° C. 143° C. Compound of Ex. 40 267° C.  — ° C. Compound of Ex. 41 267° C. 126° C. Compound of Ex. 42 290° C. 119° C. Compound of Ex. 43 255° C. 138° C. Compound of Ex. 44  —° C. 130° C. Compound of Ex. 45 258° C. 116° C. Compound of Ex. 46 304° C. 137° C. Compound of Ex. 47 251° C. 124° C. Compound of Ex. 48  —° C. 149° C. Compound of Ex. 49  —° C. 125° C. Compound of Ex. 50 309° C.  —° C. Compound of Ex. 51 237° C. 125° C. Compound of Ex. 52 262° C. 109° C. Compound of Ex. 53  —° C. 110° C. Compound of Ex. 54  —° C. 126° C. Compound of Ex. 55 336° C.  —° C.

[0348] The compounds having a benzazole ring structure obtained in Examples 1 to 55 above had a glass transition point of 98° C. or higher, which means that these compounds are stable in the form of a thin film.

Example 57

[0349] A vapor-deposited film (thickness: 100 nm) of the compound having a benzazole ring structure obtained in Examples 1 to 55 above was formed on an ITO substrate, and the work function was measured using an ionization potential measuring device (PYS-202 manufactured by Sumitomo Heavy Industries, Ltd.). Table 2 shows the results.

TABLE-US-00002 TABLE 2 Compound Work function Compound of Ex. 1 6.38 eV Compound of Ex. 2 6.42 eV Compound of Ex. 3 6.40 eV Compound of Ex. 4 6.31 eV Compound of Ex. 5 6.35 eV Compound of Ex. 6 6.37 eV Compound of Ex. 7 6.40 eV Compound of Ex. 8 6.36 eV Compound of Ex. 9 6.46 eV Compound of Ex. 10 6.31 eV Compound of Ex. 11 6.46 eV Compound of Ex. 12 6.38 eV Compound of Ex. 13 6.24 eV Compound of Ex. 14 6.41 eV Compound of Ex. 15 6.38 eV Compound of Ex. 16 6.40 eV Compound of Ex. 17 6.41 eV Compound of Ex. 18 6.39 eV Compound of Ex. 19 6.49 eV Compound of Ex. 20 6.69 eV Compound of Ex. 21 6.39 eV Compound of Ex. 22 6.53 eV Compound of Ex. 23 6.52 eV Compound of Ex. 24 6.41 eV Compound of Ex. 25 6.51 eV Compound of Ex. 26 6.30 eV Compound of Ex. 27 6.41 eV Compound of Ex. 28 6.38 eV Compound of Ex. 29 6.40 eV Compound of Ex. 30 6.45 eV Compound of Ex. 31 6.44 eV Compound of Ex. 32 6.38 eV Compound of Ex. 33 6.38 eV Compound of Ex. 34 6.52 eV Compound of Ex. 35 6.51 eV Compound of Ex. 36 6.46 eV Compound of Ex. 37 6.38 eV Compound of Ex. 38 6.29 eV Compound of Ex. 39 6.47 eV Compound of Ex. 40 6.35 eV Compound of Ex. 41 6.37 eV Compound of Ex. 42 6.19 eV Compound of Ex. 43 6.36 eV Compound of Ex. 44 6.43 eV Compound of Ex. 45 6.40 eV Compound of Ex. 46 6.40 eV Compound of Ex. 47 6.38 eV Compound of Ex. 48 6.42 eV Compound of Ex. 49 6.38 eV Compound of Ex. 50 6.36 eV Compound of Ex. 51 6.41 eV Compound of Ex. 52 6.40 eV Compound of Ex. 53 6.38 eV Compound of Ex. 54 6.39 eV Compound of Ex. 55 6.31 eV

[0350] The compounds having a benzazole ring structure obtained in Examples 1 to 55 above had a work function larger than 5.5 eV, whereas the work function of common hole-transporting materials such as NPD and TPD is generally 5.5 eV. This means that the compounds having a benzazole ring structure obtained in Examples have good hole-blocking capability.

Example 58

[0351] An organic EL element as shown in FIG. 15 was prepared by vapor-depositing, on an ITO electrode as a transparent anode 2 that had been formed on a glass substrate 1, a hole-injecting layer 3, a hole-transporting layer 4, a light-emitting layer 5, a hole-blocking layer 6, an electron-transporting layer 7, an electron-injecting layer 8, and a cathode (aluminum electrode) 9 in this order.

[0352] Specifically, a glass substrate 1 having an ITO film with a thickness of 50 nm as a transparent anode 2 was ultrasonically cleaned in isopropyl alcohol for 20 minutes, and then dried for 10 minutes on a hot plate heated to 200° C. After that, UV/ozone treatment was performed for 15 minutes. Then, the glass substrate with ITO was set inside a vacuum vapor deposition machine, and the pressure was reduced to 0.001 Pa or less. Subsequently, an electron acceptor (Acceptor-1) having the structural formula below and a compound (HTM-1) having the structural formula below were vapor-deposited so as to coat the transparent anode 2 through binary vapor deposition at vapor deposition rates such that the ratio of the vapor deposition rate of Acceptor-1 to that of HTM-1 was 3:97, to thereby form a hole-injecting layer 3 with a thickness of 10 nm.

[0353] On this hole-injecting layer 3, a hole-transporting layer 4 (thickness: 60 nm) made of the compound (HTM-1) having the structural formula below was formed.

[0354] A compound (EMD-1) having the structural formula below and a compound (EMH-1) having the structural formula below were vapor-deposited on the hole-transporting layer 4 through binary vapor deposition at vapor deposition rates such that the ratio of the vapor deposition rate of EMD-1 to that of EMH-1 was 5:95, to thereby form a light-emitting layer 5 with a thickness of 20 nm.

[0355] The compound of Example 1 (Compound-2) and a compound (ETM-1) having the structural formula below were vapor-deposited on this light-emitting layer 5 through binary vapor deposition at vapor deposition rates such that the ratio of the vapor deposition rate of Compound-2 to that of ETM-1 was 50:50, to thereby from a layer (thickness: 30 nm) serving as both a hole-blocking layer 6 and an electron-transporting layer 7.

[0356] On this layer serving as both the hole-blocking layer 6 and the electron-transporting layer 7, an electron-injecting layer 8 (thickness: 1 nm) made of lithium fluoride was formed. Finally, aluminum was vapor-deposited to a thickness of 100 nm to thereby form a cathode 9.

[0357] The prepared organic EL element were characterized in the atmosphere at normal temperature. Tables 3 and 4 collectively show the measurement results of light emission characteristics when a DC voltage was applied to the prepared organic EL element.

##STR00066## ##STR00067##

Examples 59 to 112

[0358] Organic EL elements were prepared under the same conditions as in Example 58, except that, instead of the compound of Example 1 (Compound-2), the compounds of Examples 2 to 55, respectively, were used as the material for the layer serving as both the hole-blocking layer 6 and the electron-transporting layer 7, and that binary vapor deposition was performed at vapor deposition rates such that the ratio of the vapor deposition rate of the compounds of Examples 2 to 55 to that of ETM-1 was 50:50. The prepared organic EL elements were characterized in the atmosphere at normal temperature. Tables 3 and 4 collectively show the measurement results of light emission characteristics when a DC voltage was applied to the prepared organic EL element.

Comparative Example 1

[0359] For comparison, an organic EL element was prepared under the same conditions as in Example 58, except that, instead of the compound of Example 1 (Compound-2), a compound (ETM-2) having the structural formula below (see Patent Literature 8, for example) was used as the material for the layer serving as both the hole-blocking layer 6 and the electron-transporting layer 7, and that binary vapor deposition was performed at vapor deposition rates such that the ratio of the vapor deposition rate of ETM-2 to that of ETM-1 was 50:50. The prepared organic EL element was characterized in the atmosphere at normal temperature. Tables 3 and 4 collectively show the measurement results of light emission characteristics when a DC voltage was applied to the prepared organic EL element.

##STR00068##

Comparative Example 2

[0360] For comparison, an organic EL element was prepared under the same conditions as in Example 58, except that, instead of the compound of Example 1 (Compound-5), a compound (ETM-3) having the structural formula below (see Patent Literature 9, for example) was used as the material for the layer serving as both the hole-blocking layer 6 and the electron-transporting layer 7, and that binary vapor deposition was performed at vapor deposition rates such that the ratio of the vapor deposition rate of ETM-3 to that of ETM-1 was 50:50. The prepared organic EL element was characterized in the atmosphere at normal temperature. Tables 3 and 4 collectively show the measurement results of light emission characteristics when a DC voltage was applied to the prepared organic EL element.

##STR00069##

[0361] The element lifespan of the organic EL elements prepared in Examples 58 to 112 and Comparative Examples 1 and 2 was measured. Tables 3 and 4 collectively show the results. The element lifespan was defined as follows: the organic EL element was driven by constant current to emit light at an initial luminance (luminance when light emission started) of 2,000 cd/m.sup.2, and the time taken for the luminance to decay to 1,900 cd/m.sup.2 (corresponding to 95% based on the initial luminance (100%): 95% decay) was determined and defined as the element lifespan.

TABLE-US-00003 TABLE 3 Layer serving as both Power hole-blocking layer and Voltage Luminance Luminous efficiency Element electron-transporting [V] [cd/m.sup.2] efficacy [cd/A] [lm/W] lifespan layer (@10 mA/cm.sup.2) (@10 mA/cm.sup.2) (@10 mA/cm.sup.2) (@10 mA/cm.sup.2) (95% decay) Ex. 58 Compound-2/ETM-1 3.54 873 8.73 7.75 294 hours Ex. 59 Compound-10/ETM-1 3.50 876 8.77 7.89 248 hours Ex. 60 Compound-22/ETM-1 3.43 894 8.95 8.21 287 hours Ex. 61 Compound-23/ETM-1 3.41 883 8.84 8.14 267 hours Ex. 62 Compound-24/ETM-1 3.43 879 8.80 8.06 288 hours Ex. 63 Compound-27/ETM-1 3.51 866 8.67 7.77 247 hours Ex. 64 Compound-75/ETM-1 3.68 886 8.87 7.58 249 hours Ex. 65 Compound-77/ETM-1 3.38 887 8.87 8.25 261 hours Ex. 66 Compound-84/ETM-1 3.49 866 8.68 7.81 246 hours Ex. 67 Compound-104/ETM-1 3.48 823 8.22 7.42 288 hours Ex. 68 Compound-105/ETM-1 3.67 893 8.94 7.65 263 hours Ex. 69 Compound-106/ETM-1 3.43 877 8.78 8.05 258 hours Ex. 70 Compound-108/ETM-1 3.48 892 8.94 8.08 280 hours Ex. 71 Compound-109/ETM-1 3.53 875 8.77 7.80 270 hours Ex. 72 Compound-110/ETM-1 3.70 884 8.85 7.52 256 hours Ex. 73 Compound-111/ETM-1 3.50 879 8.80 7.91 288 hours Ex. 74 Compound-115/ETM-1 3.44 892 8.93 8.16 251 hours Ex. 75 Compound-117/ETM-1 3.47 859 8.60 7.78 281 hours Ex. 76 Compound-118/ETM-1 3.35 888 8.89 8.34 266 hours Ex. 77 Compound-119/ETM-1 3.52 880 8.81 7.87 246 hours Ex. 78 Compound-120/ETM-1 3.47 900 9.01 8.15 271 hours Ex. 79 Compound-123/ETM-1 3.55 898 8.99 7.97 247 hours Ex. 80 Compound-127/ETM-1 3.53 852 8.53 7.59 284 hours Ex. 81 Compound-128/ETM-1 3.61 847 8.48 7.38 278 hours Ex. 82 Compound-130/ETM-1 3.46 894 8.95 8.14 249 hours Ex. 83 Compound-136/ETM-1 3.50 882 8.82 7.93 251 hours Ex. 84 Compound-137/ETM-1 3.42 877 8.77 8.06 267 hours

TABLE-US-00004 TABLE 4 Layer serving as both Power hole-blocking layer and Voltage Luminance Luminous efficiency Element electron-transporting [V] [cd/m.sup.2] efficacy [cd/A] [lm/W] lifespan layer (@10 mA/cm.sup.2) (@10 mA/cm.sup.2) (@10 mA/cm.sup.2) (@10 mA/cm.sup.2) (95% decay) Ex. 85 Compound-138/ETM-1 3.53 879 8.80 7.83 246 hours Ex. 86 Compound-143/ETM-1 3.46 893 8.94 8.13 268 hours Ex. 87 Compound-144/ETM-1 3.56 848 8.48 7.49 271 hours Ex. 88 Compound-147/ETM-1 3.53 839 8.39 7.47 300 hours Ex. 89 Compound-148/ETM-1 3.38 898 8.98 8.34 241 hours Ex. 90 Compound-149/ETM-1 3.53 892 8.93 7.95 240 hours Ex. 91 Compound-150/ETM-1 3.52 875 8.76 7.83 256 hours Ex. 92 Compound-151/ETM-1 3.56 891 8.91 7.87 279 hours Ex. 93 Compound-154/ETM-1 3.56 893 8.94 7.89 255 hours Ex. 94 Compound-155/ETM-1 3.39 874 8.74 8.10 251 hours Ex. 95 Compound-156/ETM-1 3.63 896 8.97 7.77 280 hours Ex. 96 Compound-157/ETM-1 3.51 887 8.89 7.97 276 hours Ex. 97 Compound-158/ETM-1 3.56 873 8.71 7.68 277 hours Ex. 98 Compound-159/ETM-1 3.40 900 9.00 8.31 308 hours Ex. 99 Compound-160/ETM-1 3.71 843 8.40 7.13 296 hours Ex. 100 Compound-161/ETM-1 3.42 879 8.80 8.08 260 hours Ex. 101 Compound-164/ETM-1 3.58 890 8.91 7.81 241 hours Ex. 102 Compound-165/ETM-1 3.53 883 8.84 7.88 272 hours Ex. 103 Compound-166/ETM-1 3.48 893 8.94 8.08 289 hours Ex. 104 Compound-167/ETM-1 3.51 864 8.66 7.76 267 hours Ex. 105 Compound-168/ETM-1 3.38 890 8.91 8.29 294 hours Ex. 106 Compound-173/ETM-1 3.59 849 8.49 7.43 241 hours Ex. 107 Compound-175/ETM-1 3.69 888 8.89 7.59 251 hours Ex. 108 Compound-179/ETM-1 3.50 909 9.10 8.19 298 hours Ex. 109 Compound-180/ETM-1 3.47 857 8.58 7.78 261 hours Ex. 110 Compound-181/ETM-1 3.53 882 8.83 7.87 277 hours Ex. 111 Compound-182/ETM-1 3.47 894 8.95 8.11 292 hours Ex. 112 Compound-201/ETM-1 3.44 874 8.75 8.00 285 hours Com.Ex. 1 ETM-2/ETM-1 3.82 805 8.05 6.62 165 hours Com.Ex. 2 ETM-3/ETM-1 4.01 659 6.59 5.16 203 hours

[0362] As shown in Tables 3 and 4, a current of 10 mA/cm.sup.2 in terms of a current density was passed through the organic EL elements, and at that time, while the organic EL elements of Comparative Examples 1 and 2 including the compounds ETM-2 and ETM-3 of the structural formulas shown above, respectively, had a driving voltage of 3.82 to 4.01 V, the organic EL elements of Examples 58 to 112 had a lower driving voltage of 3.35 to 3.71 V. While the organic EL elements of Comparative Examples 1 and 2 had a luminous efficacy of 6.59 to 8.05 cd/A, the organic EL elements of Examples 58 to 112 had an improved luminous efficiency of 8.22 to 9.10 cd/A. While the organic EL elements of Comparative Examples 1 and 2 had a power efficiency of 5.16 to 6.62 lm/W, the organic EL elements of Examples 58 to 112 had a significantly improved power efficiency of 7.13 to 8.34 lm/W. While the organic EL elements of Comparative Examples 1 and 2 had an element lifespan (95% decay) of 165 to 203 hours, the organic EL elements of Examples 58 to 112 had a significantly longer lifespan of 240 to 308 hours.

[0363] It can be seen from the above that the organic EL elements of the present invention have excellent luminous efficacy and power efficiency as well as a longer lifespan, compared with elements including the compounds ETM-2 and ETM-3 having the structural formulae shown above.

INDUSTRIAL APPLICABILITY

[0364] The compound having a specific benzazole ring structure of the present invention has good electron-injecting properties and hole-blocking capability, and is stable in the form of a thin film, and the compound of the present invention is therefore an excellent compound for an organic EL element. An organic EL element prepared by using this compound can achieve high efficiency and also achieve a reduced driving voltage and hence improved durability. Thus, the organic EL element can be applied to uses such as home electric appliances and lighting equipment, for example.