JP2012144454A - Imidazole compound, imidazole-based compound, organometallic complex, material for organic electroluminescence element, organic electroluminescence element, display device, and illumination device - Google Patents

Abstract

The present invention provides an imidazole compound that has a sharp emission spectrum and can be used as a light emitting material capable of emitting light on the short wavelength side.
In the following general formula (1), an imidazole compound in which R ₁ represents a substituent having a steric parameter (Es) value of -2.0 or less.

(In General Formula (1), Z ₁ represents an atomic group of a hydrocarbon ring group or a heterocyclic group, and Z ₂ represents an atomic group of a 5-membered or 6-membered hydrocarbon ring or heterocyclic ring together with C—C. )
[Selection figure] None

Description

  The present invention relates to an imidazole compound, an imidazole compound, an organometallic complex, a material for an organic electroluminescence element, an organic electroluminescence element, a display device, and a lighting device.

Conventionally, imidazole compounds have been used in various applications, but in recent years, they have also been used as materials for organic electroluminescence devices. For example, an imidazole compound is used as a ligand of a metal complex.
Patent Document 1 and Patent Document 2 describe N-phenyl-2-phenylimidazole derivatives in which substituents are introduced at the 2-position and the 6-position of the N-position phenyl group. Examples of this substituent include a methyl group, an isopropyl group, a phenyl group, a 4-isopropylphenyl group, and a 3,5-dimethylphenyl group. In Patent Document 2, the bulkiness of the substituent is defined by a steric parameter (Es value).
Patent Documents 1 and 2 describe that metal complexes having imidazole compounds into which a bulky substituent is introduced at the 2-position and 6-position of the N-position phenyl group have a short emission wavelength. The emission spectrum becomes sharper and the emission spectrum becomes sharper, so that it is useful as a blue light-emitting material with excellent color purity.

Special table 2008-542203 gazette JP 2008-303150 A

  However, in the synthesis methods disclosed in Patent Document 1 and Patent Document 2, the yield decreases as the bulk of the substituent of the imidazole compound increases (as the Es value decreases), and further, the synthesis cannot be performed. For example, if the substituent is a methyl group, it can be synthesized, but the yield of an imidazole compound having an isopropyl group or a phenyl group is very low, not at a practical level, and a carbazole group that is a bulky substituent. It is not possible to synthesize imidazole compounds having Patent Documents 1 and 2 disclose synthesis examples of imidazole compounds having an isopropyl group or a phenyl group, but do not disclose synthesis examples of imidazole compounds having a bulky substituent. Therefore, it can be said that it cannot be provided at a practical level.

  Under such circumstances, in order to obtain a light emitting material having a sharp emission spectrum and capable of emitting light on the short wavelength side, an imidazole compound having a bulky substituent introduced at the 2nd and 6th positions of the phenyl group at the N position is desired. It is rare.

  An object of the present invention is to provide an imidazole compound useful for obtaining a light-emitting material having a sharp emission spectrum and capable of emitting light on a short wavelength side, an imidazole compound having this imidazole compound as a partial structure, an organometallic complex, and an organic electroluminescence containing them. It is providing the element material, the organic electroluminescent element using this organic electroluminescent element material, a display apparatus provided with this organic electroluminescent element, and an illuminating device.

The imidazole compound of the present invention is characterized in that, in the following general formula (1), R ₁ represents a substituent having a steric parameter (Es) value of −2.0 or less.

(However, in the general formula (1),
Z ₁ represents an atomic group necessary for forming a hydrocarbon ring group or a heterocyclic group, and the hydrocarbon ring group or the heterocyclic group formed in Z ₁ represents one or more of R ₁ Have
R ₂ and R ₃ represent a bond, a hydrogen atom or an aromatic hydrocarbon group, and are bonded to each other to form a 5-membered hydrocarbon ring, a 6-membered hydrocarbon ring, a 5-membered heterocycle or a 6-membered heterocycle. A ring may be formed, and these rings may have a substituent,
Z ₂ represents an atomic group necessary to form a 5-membered hydrocarbon ring, a 6-membered hydrocarbon ring, a 5-membered heterocyclic ring or a 6-membered heterocyclic ring together with C—C;
R ₄ represents a hydrogen atom or a substituent,
m represents an integer of 1 to 5. )

In the imidazole compound of the present invention,
R ₁ preferably represents a substituent having a steric parameter (Es) value of −2.5 or less.

In the imidazole compound of the present invention,
R ₁ preferably represents a substituent having a steric parameter (Es) value of −3.0 or less.

In the imidazole compound of the present invention,
R ₁ preferably represents a substituent having a steric parameter (Es) value of −5.0 or less.

In the imidazole compound of the present invention,
R ₁ preferably represents a substituent having a molecular weight of 42 or more.

In the imidazole compound of the present invention,
R ₁ preferably represents a substituent having a molecular weight of 76 or more.

In the imidazole compound of the present invention,
R ₁ preferably represents a substituent having a molecular weight of 115 or more.

In the imidazole compound of the present invention,
R ₁ preferably represents a substituent having a molecular weight of 166 or more.

The imidazole compound of the present invention is
It has the imidazole compound of the present invention as a partial structure.

The organometallic complex of the present invention is
It has the imidazole compound of the present invention as a partial structure.

In the organometallic complex of the present invention,
It is preferable to include at least one metal element selected from the group 8 to group 11 metal elements of the periodic table.

The material for an organic electroluminescence element of the present invention is
It contains at least one of the imidazole compound of the present invention, the imidazole compound of the present invention, and the organometallic complex of the present invention.

The organic electroluminescence element of the present invention is
Having a plurality of organic compound layers including a light emitting layer between an anode and a cathode;
At least one layer of the organic compound layers includes the material for an organic electroluminescence element of the present invention.

The display device of the present invention includes:
The organic electroluminescence element of the present invention is provided.

The lighting device of the present invention is
The organic electroluminescence element of the present invention is provided.

  According to the present invention, an imidazole compound useful for obtaining a luminescent material having a sharp emission spectrum and capable of emitting light on a short wavelength side, an imidazole compound having the imidazole compound as a partial structure, an organometallic complex, and an organic electroluminescence containing them It is possible to provide an element material, an organic electroluminescence element using the organic electroluminescence element material, a display device including the organic electroluminescence element, and a lighting device.

It shows a ¹ H-NMR spectrum of the imidazole compound. ¹ H-NMR enlarged view of a part of the spectrum of FIG. The figure which shows a high performance liquid chromatography analysis result.

[Imidazole compound]
The imidazole compound of the present invention is represented by the general formula (1).
In the general formula (1), Z ₁ represents an atomic group necessary for forming a hydrocarbon ring group or a heterocyclic group. These hydrocarbon ring groups or heterocyclic groups have one or more substituents represented by R ₁ described below. The number is preferably one of 1, 2, 3, 4, and 5. When the number of R ₁ is plural, each R ₁ may be the same or different. Of the imidazole compounds represented by the general formula (1), imidazole compounds each having R ₁ at the ortho position of the hydrocarbon ring group or heterocyclic group are preferred.

In the general formula (1), R ₁ represents a substituent having a steric parameter (Es) value of −2.0 or less. Preferably, it is a substituent having an Es value of −2.5 or less, more preferably a substituent having an Es value of −3.0 or less, and still more preferably a substituent having an Es value of −5.0 or less. It is a group.
The Es value is a steric parameter derived from chemical reactivity, and it can be said that the smaller this value is, the sterically bulky substituent. Therefore, the smaller the Es value, the better.
Regarding the Es value, for example, “Structure Activity Relationship of Drugs, Guidelines for Drug Design and Action Mechanism Research (Chemistry Domain Extra Number 122)” (Nanedo 1979) p124-126, Unger, S. H. Hansch, C .; , Prog. Phys. Org. Chem. 12, 91 (1976), “American Chemical Society Reference Book, 'Exploring QSAR' p. 81 Table 3-3”.

The Es value in the present invention is a value represented by assuming that the Es value of a hydrogen atom is 0.
Examples of the substituent having an Es value of −2.0 or less include —CF ₃ (trifluoromethyl group), 9-H-fluorene group (Es value = −2.34), and a carbazolyl group. Examples of the substituent having a value of −2.5 or less include —tC ₄ H ₉ (tert-butyl group), and examples of the substituent having an Es value of −3.0 or less include —CH ( C ₂ H ₅ ) ₂ (3- (n-pentyl) group), —CHBr ₂ (dibromomethyl group), —CCl ₃ (trichloromethyl group), —CBr ₃ (tribromomethyl group), and Es value Examples of the substituent having a value of −5.0 or less include —C (C ₆ H ₅ ) ₃ (triphenylmethyl group). Substituent Y described later may be further substituted with respect to these substituents. The Es value of the carbazolyl group is presumed to be within the range of -2.0 to -2.5 because the 9-H-fluorene group and the carbazolyl group are similar in structure.

In the general formula (1), R ₁ satisfies the range of the Es value and is preferably a substituent having a molecular weight of 43 or more, more preferably a substituent having a molecular weight of 77 or more, and a molecular weight of 116. The above substituents are more preferable, the molecular weight is more preferably 127 or more, and the molecular weight is more preferably 166 or more. Examples of the substituent having a molecular weight of 43 or more include an isopropyl group (molecular weight: 43), and examples of the substituent having a molecular weight of 77 or more include a phenyl group (molecular weight: 77), and a molecular weight of 116 or more. Examples of the substituent include, for example, an indole group (molecular weight: 116). Examples of the substituent having a molecular weight of 127 or more include a naphthyl group (molecular weight: 127), and examples of the substituent having a molecular weight of 166 or more. Is, for example, a carbazole group (molecular weight: 166).

· As hydrocarbon ring group mentioned above, in the general formula (1), Z ₁ is representative of the atomic group necessary to form a hydrocarbon ring group, As the hydrocarbon ring group, a cycloalkyl group Or an aryl group (aromatic ring group) is mentioned. These groups may have a substituent Y described later.

-Cycloalkyl group Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclododecyl group, and a norbornyl group. The cycloalkyl group preferably has 5 to 10 carbon atoms, and more preferably 5 to 7 carbon atoms.

Aryl group As the aryl group, phenyl group, 1-naphthyl group, 2-naphthyl group, 1-anthryl group, 2-anthryl group, 9-anthryl group, 1-phenanthryl group, 2-phenanthryl group, 3-phenanthryl group 4-phenanthryl group, 9-phenanthryl group, 1-naphthacenyl group, 2-naphthacenyl group, 9-naphthacenyl group, 1-pyrenyl group, 2-pyrenyl group, 4-pyrenyl group, biphenyl-2-yl group, biphenyl- 3-yl group, biphenyl-4-yl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl Group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-tolyl group, m-tolyl group, p-tolyl group, pt-butylphenyl group P- (2-phenylpropyl) phenyl group, 3-methyl-2-naphthyl group, 4-methyl-1-naphthyl group, 4-methyl-1-anthryl group, 4′-methylbiphenyl-4-yl group, Examples thereof include a 4 ″ -t-butyl-p-terphenyl-4-yl group, a fluorenyl group, etc. The aryl group preferably has 6 to 18 carbon atoms, more preferably 6 to 12 carbon atoms. It is as follows.

· As heterocyclic groups described above, in the general formula (1), Z ₁ is representative of even atomic group necessary to form a heterocyclic group, the heterocyclic group, aliphatic heterocyclic group, an aromatic Group heterocyclic group and the like.

Aliphatic heterocyclic group As the aliphatic heterocyclic group, epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring , Tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, 1,3-dioxane ring , 1,4-dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine-1, 1-dioxide ring, pyranose ring, diazabicyclo [2,2,2] -octane ring Name the origin It is possible. The aliphatic heterocyclic group preferably has 5 to 10 ring atoms, and more preferably 5 to 7 ring atoms.

Aromatic heterocyclic group As the aromatic heterocyclic group, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazole) -1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group Dibenzofuryl group, benzothienyl group, dibenzothienyl group, indolyl group, carbazolyl group, carbolinyl group, diazacarbazolyl group (one in which one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom) Quinoxalinyl group, pyridazinyl group, triazini Group, quinazolinyl group, phthalazinyl group and the like. The aromatic heterocyclic group preferably has 5 to 18 ring atoms, and more preferably 5 to 13 ring atoms.

These hydrocarbon ring groups or heterocyclic groups may further have a substituent in addition to the substituent represented by R ₁ . Hereinafter, this substituent is referred to as a substituent Y.
Examples of the substituent Y include alkyl groups (for example, methyl group, ethyl group, propyl group, isopropyl group, tert-butyl group, pentyl group, hexyl group, octyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group). Group), cycloalkyl group (eg, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (eg, vinyl group, allyl group, etc.), alkynyl group (eg, ethynyl group, propargyl group, etc.), aromatic hydrocarbon group ( Also called aromatic hydrocarbon ring group, aromatic carbocyclic group, aryl group, etc., for example, phenyl group, p-chlorophenyl group, mesityl group, tolyl group, xylyl group, naphthyl group, anthryl group, azulenyl group, acenaphthenyl group, Fluorenyl group, phenanthryl group, indenyl group, pyrenyl group, biphenylyl group, etc.) An aromatic heterocyclic group (for example, pyridyl group, pyrimidinyl group, furyl group, pyrrolyl group, imidazolyl group, benzoimidazolyl group, pyrazolyl group, pyrazinyl group, triazolyl group (for example, 1,2,4-triazol-1-yl group, 1,2,3-triazol-1-yl group, etc.), oxazolyl group, benzoxazolyl group, thiazolyl group, isoxazolyl group, isothiazolyl group, furazanyl group, thienyl group, quinolyl group, benzofuryl group, dibenzofuryl group, benzo A thienyl group, a dibenzothienyl group, an indolyl group, a carbazolyl group, a carbolinyl group, a diazacarbazolyl group (indicating that one of the carbon atoms constituting the carboline ring of the carbolinyl group is replaced by a nitrogen atom), a quinoxalinyl group, Pyridazinyl group, triazinyl group, quinazoly Group, phthalazinyl group, etc.), heterocyclic group (eg, pyrrolidyl group, imidazolidyl group, morpholyl group, oxazolidyl group, etc.), alkoxy group (eg, methoxy group, ethoxy group, propyloxy group, pentyloxy group, hexyloxy group) Octyloxy group, dodecyloxy group, etc.), cycloalkoxy group (eg, cyclopentyloxy group, cyclohexyloxy group etc.), aryloxy group (eg, phenoxy group, naphthyloxy group etc.), alkylthio group (eg, methylthio group, etc.) Ethylthio group, propylthio group, pentylthio group, hexylthio group, octylthio group, dodecylthio group, etc.), cycloalkylthio group (eg, cyclopentylthio group, cyclohexylthio group, etc.), arylthio group (eg, phenylthio group, naphthylthio group, etc.) , Alkoxycarbonyl groups (for example, methyloxycarbonyl group, ethyloxycarbonyl group, butyloxycarbonyl group, octyloxycarbonyl group, dodecyloxycarbonyl group, etc.), aryloxycarbonyl groups (for example, phenyloxycarbonyl group, naphthyloxycarbonyl group) ), Sulfamoyl group (for example, aminosulfonyl group, methylaminosulfonyl group, dimethylaminosulfonyl group, butylaminosulfonyl group, hexylaminosulfonyl group, cyclohexylaminosulfonyl group, octylaminosulfonyl group, dodecylaminosulfonyl group, phenylaminosulfonyl) Group, naphthylaminosulfonyl group, 2-pyridylaminosulfonyl group, etc.), acyl group (for example, acetyl group, ethylcarbonyl group, propylcarbon) Nyl group, pentylcarbonyl group, cyclohexylcarbonyl group, octylcarbonyl group, 2-ethylhexylcarbonyl group, dodecylcarbonyl group, phenylcarbonyl group, naphthylcarbonyl group, pyridylcarbonyl group, etc.), acyloxy group (for example, acetyloxy group, ethylcarbonyl group) Oxy group, butylcarbonyloxy group, octylcarbonyloxy group, dodecylcarbonyloxy group, phenylcarbonyloxy group, etc.), amide group (for example, methylcarbonylamino group, ethylcarbonylamino group, dimethylcarbonylamino group, propylcarbonylamino group, Pentylcarbonylamino group, cyclohexylcarbonylamino group, 2-ethylhexylcarbonylamino group, octylcarbonylamino group, dodecylcarbonylamino , Phenylcarbonylamino group, naphthylcarbonylamino group, etc.), carbamoyl group (for example, aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, propylaminocarbonyl group, pentylaminocarbonyl group, cyclohexylaminocarbonyl group, octylaminocarbonyl group) Group, 2-ethylhexylaminocarbonyl group, dodecylaminocarbonyl group, phenylaminocarbonyl group, naphthylaminocarbonyl group, 2-pyridylaminocarbonyl group, etc.), ureido group (for example, methylureido group, ethylureido group, pentylureido group, cyclohexyl) Ureido group, octylureido group, dodecylureido group, phenylureido group naphthylureido group, 2-pyridylaminoureido group), sulfinyl group ( For example, methylsulfinyl group, ethylsulfinyl group, butylsulfinyl group, cyclohexylsulfinyl group, 2-ethylhexylsulfinyl group, dodecylsulfinyl group, phenylsulfinyl group, naphthylsulfinyl group, 2-pyridylsulfinyl group, etc.), alkylsulfonyl group (for example, Methylsulfonyl group, ethylsulfonyl group, butylsulfonyl group, cyclohexylsulfonyl group, 2-ethylhexylsulfonyl group, dodecylsulfonyl group, etc.), arylsulfonyl group or heteroarylsulfonyl group (for example, phenylsulfonyl group, naphthylsulfonyl group, 2-pyridyl group) Sulfonyl group, etc.), amino group (for example, amino group, ethylamino group, dimethylamino group, butylamino group, cyclopentylamino group, 2-ethyl) Xylamino group, dodecylamino group, anilino group, naphthylamino group, 2-pyridylamino group, etc.), halogen atom (eg, fluorine atom, chlorine atom, bromine atom etc.), fluorinated hydrocarbon group (eg, fluoromethyl group, trimethyl group) Fluoromethyl group, pentafluoroethyl group, pentafluorophenyl group, etc.), cyano group, nitro group, hydroxy group, mercapto group, silyl group (for example, trimethylsilyl group, triisopropylsilyl group, triphenylsilyl group, phenyldiethylsilyl group) Etc.), and phosphono groups.

In the general formula (1), R ₂ and R ₃ represent a bond, a hydrogen atom or an aromatic hydrocarbon group, and are bonded to each other to form a 5-membered hydrocarbon ring, a 6-membered hydrocarbon ring, a 5-membered hydrocarbon ring, A heterocycle or a 6-membered heterocycle may be formed. Further, these rings may have the substituent Y.
Examples of the 5-membered or 6-membered hydrocarbon ring include a cyclopentane ring, a cyclopentadiene ring, a cyclohexane ring, a cyclohexadiene ring, and a benzene ring.
As the 5-membered or 6-membered heterocyclic ring, a 5-membered or 6-membered aromatic heterocyclic ring (for example, oxazole ring, oxadiazole ring, oxatriazole ring, isoxazole ring, tetrazole ring, thiadiazole ring, thiatriazole) Ring, isothiazole ring, thiophene ring, furan ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, imidazole ring, pyrazole ring, triazole ring), 5-membered to 6-membered non-aromatic heterocycle Ring (for example, pyrrolidine ring, piperazine ring, pyrazolidine ring, imidazolidine ring, isoxazolidine ring, isothiazolidine ring).

In the general formula (1), Z ₂ represents an atomic group necessary for forming a 5-membered hydrocarbon ring, a 6-membered hydrocarbon ring, a 5-membered heterocyclic ring or a 6-membered heterocyclic ring together with C—C. To express.
The 5-membered hydrocarbon ring, 6-membered hydrocarbon ring, 5-membered heterocycle or 6-membered heterocycle is the same as described for R ₂ and R ₃ above.

In the general formula (1), R ₄ represents a hydrogen atom or a substituent. Examples of the substituent include the substituent Y.
In general formula (1), m represents an integer of 1 to 5. When the number of R ₄ is 2 or more, each R ₄ may be the same or different.

In the general formula (1), the hydrocarbon ring group formed by Z ₁ is preferably an aryl group, more preferably a phenyl group.
Further, R ₁ is preferably substituted at the 2-position and 6-position of the phenyl group.

  Specific examples of the structure of the imidazole compound of the present invention include the following. However, the present invention is not limited to imidazole compounds having these structures.

[Method for producing imidazole compound]
The imidazole compound represented by the general formula (1) of the present invention is produced by the method described below.
The imidazole compound represented by the general formula (1) is a compound represented by the following general formulas (2) and (3), if necessary, at least one of an inorganic basic compound and an organic basic compound It can be produced by reacting in an organic solvent in the presence of a metal catalyst in the presence of the metal catalyst (hereinafter, this reaction is referred to as reaction 1).

In the general formula (2), X represents a halogen atom, and Z ₂ , R ₄ , and m are respectively synonymous with the general formula (1).

In General Formula (3), M represents a boron atom, a magnesium atom, a silicon atom, a tin atom, or a zinc atom that may have a substituent, and Z ₁ , R ₁ , R ₂ , and R ₃ are Each is synonymous with Formula (1).

Examples of the inorganic basic compound used as necessary during the reaction 1 include sodium carbonate, potassium carbonate, cesium carbonate, and potassium phosphate.
Examples of the organic basic compound used as necessary in the reaction 1 include sodium acetate, potassium acetate, sodium tert-butoxide, potassium tert-butoxide and the like.

As the metal catalyst used in the reaction 1, a palladium catalyst, a nickel catalyst, or the like is preferably used.
As the palladium catalyst, a palladium compound having a phosphine ligand is preferably used, and examples thereof include Pd (PPh ₃ ) ₄ , PdCl ₂ (PPh ₃ ) _{2 and the} like. Pd (OAc) ₂ , Pd (dba) ₂ , Pd ₂ (dba) _{3 and} other palladium compounds not containing a phosphine ligand, and PPh ₃ , tricyclohexylphosphine, tri-tert-butylphosphine, dppe, dppp, dppf and other phosphine ligands in the reaction system The palladium compound which has a phosphine ligand can also be prepared in the said reaction system by mixing by.
In addition to these, palladium catalysts used for carbon-carbon (CC) bond formation known to those skilled in the art are suitably used.
As the nickel catalyst, a nickel compound having a phosphine ligand is preferably used, and examples thereof include NiCl ₂ (dppe), NiCl ₂ (dppf), and NiCl ₂ (PPh ₃ ) ₂ . In addition to these, nickel catalysts used for CC bond formation known to those skilled in the art are preferably used.

As the organic solvent used in the reaction 1, an ether solvent, an aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, or the like is preferably used.
In the reaction system of Reaction 1, it is preferable that the amount of the ether solvent having 5 or less carbon atoms is small. Specifically, in carrying out the reaction 1, the total volume V _A [liter] of the number of moles N _f2 [mol] of the compound represented by the general formula (2) and the ether solvent having 5 or less carbon atoms in the reaction system. Preferably satisfies the relationship of the following formula (1), more preferably satisfies the relationship of the following formula (2), and more preferably satisfies the relationship of the following formula (3). V _A is the sum of these when a plurality of types of ether solvents having 5 or less carbon atoms are contained in the reaction system.

[Equation 1]
V _A / N _f2 ≦ 3 (1)

[Equation 2]
V _A / N _f2 ≦ 2 (2)

[Equation 3]
V _A / N _f2 ≦ 1 (3)

  In order to satisfy any one of the formulas (1) to (3), the amount of the ether solvent having 5 or less carbon atoms added when the reaction 1 is charged can be adjusted. In addition, when the relationship of the following mathematical formula (4) is established before the reaction 1 due to the solubility of the reagent used in the reaction 1 or the convenience of the process before the reaction 1, the reaction system includes On the other hand, a solvent removal process is performed, and the amount of the ether solvent having 5 or less carbon atoms is adjusted so as to satisfy any one of the formulas (1) to (3).

[Equation 4]
V _A / N _f2 > 3 (4)

Examples of the ether solvent having 5 or less carbon atoms include tetrahydrofuran, tetrahydropyran, 1,4-dioxane, 1,3-dioxane, diethyl ether, and 1,2-dimethoxyethane.
Solvent removal methods include solvent distillation under reduced pressure using a solvent trap vessel and various vacuum pumps cooled by various cooling systems, and solvent under normal pressure using a Dean-Stark trap. An atmospheric distillation method for removing water can be used.

In addition, when the reaction system contains at least one solvent selected from an ether solvent having 6 or more carbon atoms, an aliphatic hydrocarbon solvent having 7 or more carbon atoms, and an aromatic hydrocarbon solvent, an ether having 5 or less carbon atoms Even more preferable than the case of carrying out only with a solvent.
In this case, when performing the reaction 1, the total volume V _B [of the at least one solvent selected from an ether solvent having 6 or more carbon atoms, an aliphatic hydrocarbon solvent having 7 or more carbon atoms, and an aromatic hydrocarbon solvent in the reaction system. Liter] and the number of moles N _f2 [mol] of the compound represented by the general formula (2) preferably satisfy the relationship of the following formula (5), and more preferably satisfy the relationship of the following formula (6). .

[Equation 5]
V _B / N _f2 ≧ 0.1 (5)

[Equation 6]
10 ≧ V _B / N _f2 ≧ 0.1 (6)

Preferred examples of the ether solvent having 6 or more carbon atoms include dipropyl ether, dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, methoxybenzene, ethoxybenzene, methylanisole, ethylanisole, dimethoxybenzene, and methoxyethoxybenzene.
Preferred examples of the aliphatic hydrocarbon solvent having 7 or more carbon atoms include n-heptane, n-octane, n-nonane and n-decane.
The aromatic hydrocarbon solvent is preferably selected from aromatic hydrocarbon solvents having 6 to 20 carbon atoms, and preferred examples include benzene, toluene, xylene, ethylbenzene, trimethylbenzene, and tetramethylbenzene.

By performing the reaction 1 under such conditions, a hydrocarbon ring in which R ₁ , which is a bulky substituent that cannot be synthesized by the synthesis method disclosed in the prior art, is formed by Z _{1 is used} . An imidazole compound existing in a group or heterocyclic group can be synthesized.

[Imidazole compounds]
The imidazole compound of the present invention has an imidazole compound represented by the general formula (1) as a partial structure. In other words, even if the compound has a structure represented by the general formula (1) even if partially, it corresponds to the imidazole compound of the present invention. Therefore, for example, polysubstituted compounds such as L-76 to L-91 exemplified as imidazole compounds also correspond to the imidazole compounds of the present invention.
Although the specific example is further added and shown next about the imidazole type compound of this invention, it is not limited to these.

[Organic metal complex]
The organometallic complex of the present invention has an imidazole compound represented by the general formula (1) as a partial structure.
The organometallic complex of the present invention preferably contains at least one metal selected from metal elements from Group 8 to Group 11 of the Periodic Table. The metal is preferably platinum or iridium.
The organometallic complex of the present invention includes, for example, those having an imidazole compound represented by the general formula (1) as a ligand for the metal elements from Group 8 to Group 11 of the Periodic Table. . The organometallic complex of the present invention can be synthesized by a known method.
The organometallic complex of the present invention has an imidazole compound represented by the general formula (1) as a ligand, so that it can be used as a light emitting material having a sharp emission spectrum and capable of emitting light on a short wavelength side. Therefore, it is particularly useful as a blue light emitting organic EL device material.

  Specific examples of the organometallic complex having the imidazole compound of the present invention in its partial structure are shown below, but the invention is not limited thereto.

[Materials for organic electroluminescence elements]
The material for an organic electroluminescence device of the present invention preferably contains at least one of the imidazole compound represented by the general formula (1), the organic compound, and the organometallic complex. Hereinafter, the organic electroluminescence element is referred to as an organic EL element, and the organic electroluminescence element material is referred to as an organic EL element material.

[Organic EL elements, display devices, lighting devices]
The organic EL device of the present invention has an organic compound layer between the cathode and the anode, and the organic compound layer includes at least one layer composed of the organic compound. The organic compound layer may contain an inorganic compound.
In the organic EL element of the present invention, at least one layer of the organic compound layers contains the organic EL element material. The organic compound layer has at least one light emitting layer. Therefore, the organic compound layer may be composed of, for example, a single light emitting layer, and is used in known organic EL elements such as a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. The layers to be stacked may be laminated via the light emitting layer.
As the structure of the multilayer organic EL element, for example,
(A) Anode / hole injection / transport layer / light emitting layer / cathode,
(B) Anode / light emitting layer / electron injection / transport layer / cathode,
(C) Anode / hole injection / transport layer / light emitting layer / electron injection / transport layer / cathode,
(D) Anode / hole injection / transport layer / light emitting layer / hole barrier layer / electron injection / transport layer / cathode,
The thing laminated | stacked by the multilayer structure of these is mentioned.
The “hole injection / transport layer” means “at least one of a hole injection layer and a hole transport layer”, and “electron injection / transport layer” means “electron injection layer and electron transport layer”. It means “at least one of the layers”.

The organic EL device material containing the imidazole compound of the present invention or the imidazole compound of the present invention can also be used as a host of the light emitting layer, and the organic EL device material containing the organometallic complex of the present invention is used as a dopant of the light emitting layer. It can also be used.
In the latter case, the organometallic complex of the present invention has a sharp emission spectrum as described above and emits light on the short wavelength side, so that it is particularly useful for forming a blue light emitting layer.
Not only an organic EL element having a blue light emitting layer but also an organic EL element having a red light emitting layer and an organic EL element having a green light emitting layer can be arranged side by side to constitute a display device or a lighting device capable of color display.
Alternatively, a red light emitting layer and a green light emitting layer may be separately laminated on the blue light emitting layer to constitute a white light emitting organic EL element. In this case, a so-called tandem element structure is preferable. An organic EL element that emits white light can also be suitably used for a display device and a lighting device.

  In the organic EL device of the present invention, in addition to the organic EL device material of the present invention, any material can be selected and used from known materials used in conventional organic EL devices.

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

[Example 1] Synthesis of imidazole compound (Synthesis Example 1) Synthesis of Compound 1 (2-Fluoro-1,3-diiodobenzene)

Under a nitrogen atmosphere, 2-Fluoroiodobenzene (75.0 g, 338 mmol) and tetrahydrofuran (676 ml) were added to a three-necked flask and cooled to −70 ° C., and diisopropylamine (41.0 g, 405.6 mmol) and an n-BuLi hexane solution were previously added thereto. (228.1 ml, number of moles of n-BuLi in solution: 371.8 mmol, mole concentration (number of moles of n-BuLi / volume of solution): 1.63 M), and 20 ml of lithium diisopropylamide / tetrahydrofuran solution prepared from tetrahydrofuran (300 ml) It was added dropwise over a period of minutes. After stirring at −70 ° C. for 1 hour, iodine (94.4 g, 371.8 mmol) was added, the temperature was slowly returned to room temperature, and the mixture was stirred for 12 hours.
After completion of the reaction, the reaction mixture was deactivated by adding a small amount of water, and then concentrated with an evaporator. Residual iodine was deactivated by adding sodium thiosulfate / sodium hydroxide aqueous solution, and the sample was transferred to a separatory funnel and extracted three times with dichloromethane. The extract was dried over anhydrous magnesium sulfate, filtered and concentrated. This was purified by silica gel chromatography (hexane) and recrystallized from hexane (150 ml) at −10 ° C. to obtain a white solid (compound 1. 2-Fluoro-1,3-diiodobenzene).
This compound 1 was identified by ¹ H-NMR and FD-MS.
Yield 62.0g
Yield 53%

Synthesis Example 2 Synthesis of Compound 2

Under a nitrogen atmosphere, in a three-necked flask, 2-Fluoro-1,3-diiodobenzene (61.9 g, 178 mmol), carbazole (71.4 g, 427.2 mmol), K ₃ PO ₄ (151.14 g, 712 mmol), CuI (6.78 g, 35.6 mmol) ), Trans-1,2-diaminocyclohexane (12.8 ml, 106.8 mmol) and 1,4-dioxane (178 ml) were added and refluxed for 16 hours.
After completion of the reaction, the reaction mixture was cooled to room temperature, and then the sample was dissolved in toluene (500 ml) and filtered using Celite to separate inorganic salts, and the filtrate was concentrated. Methanol was added to the filtrate to precipitate a sample, and dispersion washing was performed. The sample was collected by filtration and dried in vacuo (50 ° C., 8 hours) to obtain a white solid (Compound 2).
Compound 2 was identified by ¹ H-NMR and FD-MS.
Yield 42.57 g
Yield 56%

Synthesis Example 3 Synthesis of Compound 3

In a nitrogen atmosphere, put potassium hydride (3.0 g, 75 mmol) and N, N-dimethylformamide (50 ml) in a three-necked flask, cool to 0 ° C., and add N, N-dimethylformamide (50 ml) there. A solution of dissolved imidazole (6.81 g, 100 mmol) was added over 20 minutes while paying attention to the hydrogen gas evolution rate, and then stirred at room temperature for 1 hour. Compound 2 (21.32 g, 50 mmol) was then added and refluxed for 6 hours.
After completion of the reaction, water (200 ml) was added and the precipitated sample was collected by filtration. The sample was dissolved in dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. This was purified by silica gel chromatography (dichloromethane: ethyl acetate = 9: 1 (volume ratio)), then dispersed and washed with hexane, filtered and dried in vacuo (50 ° C., 8 hours) to give a white solid (compound 3 )
Compound 3 was identified by ¹ H-NMR and FD-MS.
Yield 17.79 g
Yield 75%

(Synthesis Example 4) Synthesis of Compound 4

Under a nitrogen atmosphere, compound 3 (5.69 g, 12 mmol) and tetrahydrofuran (72 ml) were placed in a three-necked flask, and then at room temperature, n-BuLi hexane solution (7.2 ml, moles of n-BuLi in the solution: 12 mmol, moles) Concentration (number of moles of n-BuLi / amount of solution): 1.67M) was added and stirred for 30 minutes. Next, a solution of zinc chloride (2.04 g, 15 mmol) dissolved in tetrahydrofuran (15 ml) was added over 5 minutes. n-Hexane was used as a solvent for the n-BuLi hexane solution. The same applies to comparative examples described later.
Compound 4 was directly used in the next reaction without purification.

Synthesis Example 5 Synthesis of Compound 5

After synthesizing Compound 4 in Synthesis Example 4, an oil rotary pump was connected to the three-necked flask containing Compound 4 as it was through a solvent trap cooled with a dry ice / acetone refrigerant under reduced pressure. The three-necked flask was heated to about 40 ° C. to remove the solvent (90 ml) from the reaction system (solvent removal step). Here, the removal amount of the solvent is the amount collected in the solvent trap.
Then, after cooling to room temperature, nitrogen was introduced into the system to return to normal pressure, toluene (30 ml) was added (toluene addition), then iodobenzene (2.04 g, 10 mmol), and Pd (PPh ₃ ) ₄ ( 231 mg, 0.2 mmol) was added, and the mixture was reacted at 120 ° C. for 16 hours under a nitrogen atmosphere.

Here, the relationship of the amount of solvent in the reaction system in Synthesis Example 5 is summarized in Table 1.
In addition, n-butane has n-BuLi (molecular weight MW = 64.06) changed by the reaction of Synthesis Example 4. Specifically, n-BuLi (12 mmol) becomes n-butane (molecular weight MW = 58.12, n-butane mole number: 12 mmol, n-butane mass: 0.697 g, n-butane specific gravity: 0.60) to 1.2 ml changed.
The volume of n-hexane is calculated by calculating the solution mass (4.896g) from the specific gravity (0.68) of the n-BuLi hexane solution and subtracting the mass of n-BuLi (0.769g) from the solution mass. (4.127 g) was calculated, and converted into a volume by the specific gravity of n-hexane (0.66). The same applies to the following cases.

As shown in Table 1, since the total amount of the solvent remaining in the flask after the solvent removal step was 4.4 ml, the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, was 4.4 ml. It can be said that it was the following.
Therefore, the relationship between the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, and the number of moles N _f2 [mol] of iodobenzene is as shown in Table 1.
V _A / N _f2 ≦ 0.44
Thus, the relationship of the mathematical formula (3) was satisfied.
Furthermore, as shown in Table 1, the relationship between the volume V _B [liter] of toluene which is an aromatic hydrocarbon solvent having 7 carbon atoms and the number of moles N _f2 [mol] of iodobenzene is shown in Table 1.
V _B / N _f2 = 3.0
Thus, the relationship of the formula (6) was satisfied.
Note that the reaction system in Synthesis Example 5 may contain n-hexane, which is an aliphatic hydrocarbon solvent having 6 carbon atoms, even after the solvent removal step. However, since the volume of n-hexane after the solvent removal step is smaller than the volume of toluene added thereafter, even if n-hexane is taken into account, the relationship of the formula (6) is still satisfied. This also applies to Reference Example 2 and Example 3 described later.
Therefore, the reaction conditions of Synthesis Example 5 were performed under the conditions satisfying the relations of Equation (3) and Equation (6).

After completion of the reaction, the reaction was deactivated by adding a small amount of water to the sample. This is diluted with dichloromethane (200 ml), and an aqueous solution of tetrasodium ethylenediaminetetraacetate dihydrate (8.32 g, 20 mmol) is added thereto, shaken well in a separatory funnel, and the pH of the aqueous phase becomes 10 or more. A sodium hydroxide aqueous solution was added to adjust. The dichloromethane phase was recovered, further extracted from the aqueous phase with dichloromethane several times, dried over anhydrous magnesium sulfate, filtered, concentrated and dried. This was purified by silica gel chromatography (toluene: ethyl acetate = 90: 10 (volume ratio)), and then dispersed and washed with methanol to obtain a white solid (compound 5).
Compound 5 was identified by ¹ H-NMR and FD-MS. 1 and 2 show the ¹ H-NMR spectrum of Compound 5.
Yield 2.3g
Yield 42%

[Comparative Example 1]
Synthesis Example 6 Synthesis of Compound 5

In the same manner as in Synthesis Example 4, compound 3 (5.69 g, 12 mmol), tetrahydrofuran (72 ml), and n-BuLi hexane solution (7.2 ml, the number of moles of n-BuLi in the solution: 12 mmol, molar concentration (n- Compound 4 was prepared from a solution containing 1.67 M) and zinc chloride (2.04 g, 15 mmol) dissolved in tetrahydrofuran (15 ml). After the preparation, iodobenzene (2.04 g, 10 mmol) and Pd (PPh ₃ ) ₄ (231 mg, 0.2 mmol) were added to the three-necked flask containing compound 4 and refluxed for 16 hours under a nitrogen atmosphere. That is, in Comparative Example 1, the solvent removal step was not performed, and toluene was not added.

The relationship of the amount of solvent in the reaction system in Synthesis Example 6 is summarized in Table 1.
As shown in Table 1, the relationship between the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, and the number of moles N _f2 [mole] of iodobenzene was calculated in the same manner as in Synthesis Example 5. ,
V _A / N _f2 = (72 + 15) × 10 ⁻³ / 10 × 10 ⁻³ = 8.7
Thus, the relationship of the mathematical formula (1) was not satisfied.

  After completion of the reaction, the reaction was deactivated by adding a small amount of water to the sample. This is diluted with dichloromethane (200 ml), and an aqueous solution of tetrasodium ethylenediaminetetraacetate dihydrate (8.32 g, 20 mmol) is added thereto, shaken well in a separatory funnel, and the pH of the aqueous phase becomes 10 or more. A sodium hydroxide aqueous solution was added to adjust. The dichloromethane phase was collected, extracted from the aqueous phase several times with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. From the result of the high performance liquid chromatography analysis described later, in Synthesis Example 14, Compound 5 was not confirmed.

[Liquid chromatography analysis]
Prior to silica gel chromatography purification, the samples obtained in the synthesis of Example 5 and Compound 5 of Comparative Example 1 were each prepared in 100 ml tetrahydrofuran solution using a 100 ml graduated cylinder, and then 1 / 10th. The process of diluting to a concentration (specifically, extracting 1 ml of the solution and preparing it in a 10 ml tetrahydrofuran solution using a 10 ml graduated cylinder) is repeated three times, and the sample is substantially dissolved in 100 L of tetrahydrofuran. 10 ml of a solution having a concentration corresponding to the concentration of the solution was prepared.
The results of high performance liquid chromatography analysis using this solution are shown in FIG.
-High-performance liquid chromatography analysis conditions High-performance liquid chromatography was performed under the following conditions using an Agilent 1100 series (model: binary pump G1312A) manufactured by Agilent Technologies.
Column: Inertsil ODS3V (φ4.6mm × 250mm, 5μm)
Mobile phase: 0.1% by mass HCOOH + 0.1% by mass HCOONH ₄ aqueous solution / acetonitrile = 30/70 (v / v) (volume ratio)
Flow rate: 1000μl / min
Injection volume: 5.0 μl
UV detection wavelength: 254nm

(Mass spectrometry)
Mass spectrometry was also performed, and it was confirmed that each peak component on the chart was compound 3 as a raw material and compound 5 as a target product.

Table 2 shows the yield of Compound 5 in Examples and Comparative Examples.
From the results of Table 2, yield, high performance liquid chromatography analysis, and mass spectrometry, compound 5 having a bulky substituent can be synthesized in a relatively good yield. Then, it turns out that the compound 5 cannot be synthesized.

[Reference example]
Further, synthesis examples and yields of compounds having an isopropyl group (Es value: -1.71) in which the Es value of R ₁ in the general formula (1) is larger than −2.0 are described below as reference examples. Show.

Reference Example 1 Synthesis of Imidazole Compound (Compound 8) (Synthesis Example 7) Synthesis of Compound 6

Methanol (100 ml), glyoxal aqueous solution (40% by mass) (11.4 ml, 100 mmol), and 2,6-diisopropylaniline (17.73 g, 100 mmol) were placed in a three-necked flask and stirred at room temperature for 16 hours. Thereafter, methanol (400 ml), ammonium chloride (6.42 g, 120 mmol), and an aqueous formaldehyde solution (37% by mass) (16.2 ml, 200 mmol) were added and refluxed for 8 hours.
After completion of the reaction, the mixture was concentrated with an evaporator and adjusted to pH 10 with an aqueous sodium hydroxide solution. The sample was transferred to a separatory funnel, extracted with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. This was purified by silica gel chromatography (dichloromethane: ethyl acetate = 9: 1 (volume ratio)), and recrystallized from hexane to obtain a white solid (Compound 6).
Compound 6 was identified by ¹ H-NMR and FD-MS.
Yield 9.2g
Yield 40%

Synthesis Example 8 Synthesis of Compound 7

Under a nitrogen atmosphere, Compound 5 (27.4 g, 60 mmol) and tetrahydrofuran (60 ml) were placed in a three-necked flask and dissolved. The solution was cooled to 0 ° C., and n-BuLi hexane solution (35.9 ml, mole number of n-BuLi in the solution: 60 mmol, mole concentration (number of moles of n-BuLi / amount of solution): 1.67 M) over 10 minutes The mixture was further stirred at 0 ° C. for 30 minutes. Next, a solution of zinc chloride (13.6 g, 100 mmol) dissolved in tetrahydrofuran (100 ml) was added over 10 minutes. The solution was then returned to room temperature. n-Hexane was used as a solvent for the n-BuLi hexane solution. The same applies to other examples and comparative examples described later.
Compound 7 was directly used in the next reaction without purification.

Synthesis Example 9 Synthesis of Compound 8

After preparing Compound 7 in Synthesis Example 8, an oil rotary pump was connected to the three-necked flask containing Compound 7 as it was through a solvent trap cooled with a dry ice / acetone refrigerant under reduced pressure. The three-necked flask was heated to about 40 ° C. to remove the solvent (150 ml) from the reaction system (solvent removal step). Here, the removal amount of the solvent is the amount collected in the solvent trap.
Thereafter, nitrogen was introduced into the system to return to normal pressure, and 2-tert-butyl-5-Bromopyrimidine (10.8 g, 50 mmol) and Pd (PPh ₃ ) ₄ (2.89 g, 2.5 mmol) were added to the reaction system. In addition, the mixture was reacted at 90 ° C. for 16 hours under a nitrogen atmosphere.

The relationship of the amount of solvent in the reaction system in Synthesis Example 9 is summarized in Table 1.
In addition, n-butane was produced by changing n-BuLi (molecular weight MW = 64.06) by the reaction of Synthesis Example 8. Specifically, n-BuLi (60 mmol) was changed to n-butane (60 mmol, 5.8 ml). The volume of n-butane was calculated based on the molecular weight of n-butane (MW = 58.12) and the specific gravity of n-butane (0.60).
Moreover, the volume of n-hexane was calculated | required as follows. First, the solution mass (24.4 g) is calculated from the specific gravity (0.68) of the n-BuLi hexane solution, and then the mass of n-hexane (20.56 g) is subtracted from the mass of the solution by subtracting the mass of n-BuLi (3.84 g). It calculated and calculated | required by converting into the volume with the specific gravity (0.66) of n-hexane.
These calculations are the same in the following reference examples.

As shown in Table 1, since the total amount of the solvent remaining in the flask after the solvent removal step was 47.0 ml, the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, was 47.0 ml. It can be said that it was the following.
Therefore, the relationship between the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, and the number of moles N _f2 [mol] of 2-tert-butyl-5-Bromopyrimidine is as shown in Table 1. ,
V _A / N _f2 ≦ 0.94
Thus, the relationship of the mathematical formula (3) was satisfied.

After completion of the reaction, the reaction was deactivated by adding a small amount of water to the sample. This is diluted with dichloromethane (200 ml), and an aqueous solution of tetrasodium ethylenediaminetetraacetate dihydrate (62.43 g, 150 mmol) is added thereto, shaken well in a separatory funnel, and the pH of the aqueous phase becomes 10 or more. A sodium hydroxide aqueous solution was added to adjust. The dichloromethane phase was collected, extracted from the aqueous phase several times with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. This was purified by silica gel chromatography (dichloromethane: acetone = 95: 5 (volume ratio)), and then recrystallized from a hexane / ethyl acetate mixed solvent to obtain a white solid (compound 8).
Compound 8 was identified by ¹ H-NMR and FD-MS.
Yield 15.2 g
Yield 84%

Reference Example 2 Synthesis of Imidazole Compound (Compound 9) (Synthesis Example 10) Synthesis of Compound 9

In the same process as in Synthesis Example 8, compound 6 (28.5 g, 125 mmol), tetrahydrofuran (125 ml), n-BuLi hexane solution (74.9 ml, number of moles of n-BuLi in the solution: 125 mmol, molar concentration (n Compound 7 was prepared from a solution containing 1.67M) and zinc chloride (28.4 g, 208 mmol) dissolved in tetrahydrofuran (208 ml). After the preparation, an oil rotary pump was connected to the three-necked flask containing Compound 7 through a solvent trap cooled with a dry ice / acetone refrigerant, and the three-necked flask was heated to about 40 ° C. under reduced pressure. The solvent (310 ml) was removed from the reaction system (solvent removal step). Here, the removal amount of the solvent is the amount collected in the solvent trap.
Thereafter, nitrogen was introduced into the system to return to normal pressure, and toluene (104 ml) was added to the reaction system (toluene addition), then iodobenzene (21.3 g, 104 mmol), and Pd (PPh ₃ ) ₄ (2.89 g 2.5 mmol), and the mixture was reacted at 120 ° C. for 16 hours under a nitrogen atmosphere.

Table 1 summarizes the relationship of the amount of solvent in the reaction system in Synthesis Example 10.
At this time, the relationship between the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, and the number of moles N _f2 [mol] of iodobenzene was calculated by the same calculation as in (Synthesis Example 5). As shown in 1,
V _A / N _f2 ≦ 0.96
Thus, the relationship of the mathematical formula (3) was satisfied.
Furthermore, as shown in Table 1, the relationship between the toluene volume V _B [liter] and the number of moles of iodobenzene N _f2 [mol] is as follows:
V _B / N _f2 = 1
Thus, the relationship of the formula (6) was satisfied.
Therefore, the reaction of Synthesis Example 10 was performed under the conditions satisfying the relations of Equation (3) and Equation (6).

After completion of the reaction, the reaction was deactivated by adding a small amount of water to the sample. This is diluted with dichloromethane (300 ml), an aqueous solution of tetrasodium ethylenediaminetetraacetate dihydrate (129.9 g, 312 mmol) is added thereto, shaken well in a separatory funnel, and the pH of the aqueous phase becomes 10 or more. A sodium hydroxide aqueous solution was added to adjust. The dichloromethane phase was collected, extracted from the aqueous phase several times with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. This was purified by silica gel chromatography (toluene: ethyl acetate = 95: 5 (volume ratio)), and then recrystallized from a hexane / ethyl acetate mixed solvent to obtain a white solid (compound 9).
The compound 9 was identified by ¹ H-NMR and FD-MS.
Yield 24.7g
Yield 78%

Reference Example 3 Synthesis of Imidazole Compound (Compound 10) (Synthesis Example 11) Synthesis of Compound 10

In the same process as in Synthesis Example 8, compound 6 (15.98 g, 70 mmol), tetrahydrofuran (140 ml), and n-BuLi hexane solution (41.9 ml, number of moles of n-BuLi in the solution: 70 mmol, molar concentration (n -BuLi mole number / solution amount): 1.67M) and a compound 7 was prepared from a solution containing zinc chloride (13.6 g, 100 mmol) dissolved in tetrahydrofuran (100 ml). After the preparation, an oil rotary pump was connected to the three-necked flask containing Compound 7 through a solvent trap cooled with a dry ice / acetone refrigerant, and the three-necked flask was heated to about 40 ° C. under reduced pressure. The solvent (250 ml) was removed from the reaction system (solvent removal step). Here, the removal amount of the solvent is the amount collected in the solvent trap.
Thereafter, nitrogen was introduced into the system to return to normal pressure, and toluene (50 ml) was added to the reaction system (toluene addition), and then 2-Bromodibenzofuran (12.35 g, 50 mmol), and Pd (PPh ₃ ) ₄ (2.89 g, 2.5 mmol) was added, and the mixture was reacted at 120 ° C. for 18 hours under a nitrogen atmosphere.

Table 1 summarizes the relationship of the amount of solvent in the reaction system in Synthesis Example 11.
As shown in Table 1, the relationship between the total volume V _A [liter] of tetrahydrofuran which is an ether solvent having 5 or less carbon atoms and the number of moles N _f2 [mol] of 2-Bromodibenzofuran is the same as in Synthesis Example 5. By calculation
V _A / N _f2 ≦ 0.66
Thus, the relationship of the mathematical formula (3) was satisfied.
Further, the relationship between the volume V _B [liter] of toluene and the number of moles N _f2 [mol] of 2-Bromodibenzofuran is as shown in Table 1.
V _B / N _f2 = 1
Thus, the relationship of the formula (6) was satisfied.
Therefore, the reaction of Synthesis Example 11 was performed under the conditions satisfying the relations of Equation (3) and Equation (6).

After completion of the reaction, the reaction was deactivated by adding a small amount of water to the sample. This is diluted with dichloromethane (300 ml), to which is added an aqueous solution of tetrasodium ethylenediaminetetraacetate dihydrate (62.4 g, 150 mmol), shaken well in a separatory funnel, and the pH of the aqueous phase becomes 10 or more. A sodium hydroxide aqueous solution was added to adjust. The dichloromethane phase was collected, extracted from the aqueous phase several times with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. This was purified by silica gel chromatography (dichloromethane: ethyl acetate = 95: 5 (volume ratio)), and then recrystallized from a mixed solvent of hexane / ethyl acetate to obtain a white solid (compound 10).
Compound 10 was identified by ¹ H-NMR and FD-MS.
Yield 15.8g
Yield 80%

Reference Example 4 Synthesis of Imidazole Compound (Compound 7) (Synthesis Example 12)

In the same process as in Synthesis Example 8, compound 6 (27.4 g, 60 mmol), tetrahydrofuran (60 ml), n-BuLi hexane solution (35.9 ml, number of moles of n-BuLi in the solution: 60 mmol, molar concentration (n -BuLi mole number / solution amount): 1.67M) and a compound 7 was prepared from a solution containing zinc chloride (13.6 g, 100 mmol) dissolved in tetrahydrofuran (100 ml). After the preparation, add 2-tert-butyl-5-Bromopyrimidine (10.8 g, 50 mmol) and Pd (PPh ₃ ) ₄ (2.89 g, 2.5 mmol) to the three-necked flask containing compound 7 as it is under a nitrogen atmosphere. And reacted at 90 ° C. for 16 hours. That is, in Reference Example 4, the solvent removal step was not performed, and toluene was not added.

Table 1 summarizes the relationship of the amount of solvent in the reaction system in Synthesis Example 12.
As shown in Table 1, the relationship between the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, and the number of moles N _f2 [mol] of 2-tert-butyl-5-Bromopyrimidine is By the same calculation as in Example 5,
V _A / N _f2 = 3.2
Thus, the relationship of the mathematical formula (1) was not satisfied.

After completion of the reaction, the reaction was deactivated by adding a small amount of water to the sample. This is diluted with dichloromethane (200 ml), and an aqueous solution of tetrasodium ethylenediaminetetraacetate dihydrate (62.43 g, 150 mmol) is added thereto, shaken well in a separatory funnel, and the pH of the aqueous phase becomes 10 or more. A sodium hydroxide aqueous solution was added to adjust. The dichloromethane phase was collected, extracted from the aqueous phase several times with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. This was purified by silica gel chromatography (dichloromethane: acetone = 95: 5 (volume ratio)) to obtain a white solid (compound 8).
Compound 8 was identified by ¹ H-NMR and FD-MS.
Yield 0.72g
Yield 4%

[Reference Example 5] Synthesis of imidazole compound (Compound 9) (Synthesis Example 13)

In the same process as in Synthesis Example 8, compound 6 (28.5 g, 125 mmol), tetrahydrofuran (125 ml), and n-BuLi hexane solution (74.9 ml, number of moles of n-BuLi in the solution: 125 mmol, molar concentration (n Compound 7 was prepared from a solution containing 1.67M) and zinc chloride (28.4 g, 208 mmol) dissolved in tetrahydrofuran (208 ml). After the preparation, iodobenzene (21.3 g, 104 mmol) and Pd (PPh ₃ ) ₄ (2.89 g, 2.5 mmol) were added to the three-necked flask containing Compound 7 as it was, and the mixture was refluxed for 16 hours under a nitrogen atmosphere. That is, in Reference Example 5, the solvent removal step was not performed, and toluene was not added.

Table 1 summarizes the relationship of the amount of solvent in the reaction system in Synthesis Example 12.
As shown in Table 1, the relationship between the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, and the number of moles N _f2 [mole] of iodobenzene was calculated in the same manner as in Synthesis Example 5. ,
V _A / N _f2 = 3.2
Thus, the relationship of the mathematical formula (1) was not satisfied.

  After completion of the reaction, the reaction was deactivated by adding a small amount of water to the sample. This is diluted with dichloromethane (300 ml), an aqueous solution of tetrasodium ethylenediaminetetraacetate dihydrate (129.9 g, 312 mmol) is added thereto, shaken well in a separatory funnel, and the pH of the aqueous phase becomes 10 or more. A sodium hydroxide aqueous solution was added to adjust. The dichloromethane phase was collected, extracted from the aqueous phase several times with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. However, the presence of the target product could not be confirmed by thin layer chromatography.

[Reference Example 6] Synthesis of imidazole compound (Compound 10) (Synthesis Example 14)

In the same process as in Synthesis Example 8, compound 6 (15.98 g, 70 mmol), tetrahydrofuran (140 ml), and n-BuLi hexane solution (41.9 ml, number of moles of n-BuLi in the solution: 70 mmol, molar concentration (n -BuLi mole number / solution amount): 1.67M) and a compound 7 was prepared from a solution containing zinc chloride (13.6 g, 100 mmol) dissolved in tetrahydrofuran (100 ml). After the preparation, 2-Bromodibenzofuran (12.35 g, 50 mmol) and Pd (PPh ₃ ) ₄ (2.89 g, 2.5 mmol) were added to the three-necked flask containing Compound 7 as it was, and the mixture was refluxed for 18 hours under a nitrogen atmosphere. . That is, in Reference Example 6, the solvent removal step was not performed, and toluene was not added.

The relationship of the amount of solvent in the reaction system in Synthesis Example 13 is summarized in Table 1.
As shown in Table 1, the relationship between the total volume V _A [liter] of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, and the number of moles N _f2 [mol] of 2-Bromodibenzofuran is calculated in the same manner as in Synthesis Example 5. By
V _A / N _f2 = 4.8
Thus, the relationship of the mathematical formula (1) was not satisfied.

  After completion of the reaction, the reaction was deactivated by adding a small amount of water to the sample. This is diluted with dichloromethane (300 ml), to which is added an aqueous solution of tetrasodium ethylenediaminetetraacetate dihydrate (62.4 g, 150 mmol), shaken well in a separatory funnel, and the pH of the aqueous phase becomes 10 or more. A sodium hydroxide aqueous solution was added to adjust. The dichloromethane phase was collected, extracted from the aqueous phase several times with dichloromethane, dried over anhydrous magnesium sulfate, filtered and concentrated. However, the presence of the target product could not be confirmed by thin layer chromatography.

  Table 3 compares the yields of the compounds 8 to 10 synthesized in Reference Examples 1 to 6 above.

  As shown in the yields of Reference Examples 1 to 3 in Table 3, even for the same target compound, the solvent removal step is performed to reduce the total volume of tetrahydrofuran, which is an ether solvent having 5 or less carbon atoms, and further the carbon number. By adding toluene which is an aromatic hydrocarbon solvent of No. 7, the target compound can be synthesized in high yield. On the other hand, in the synthesis methods of Reference Examples 4 to 6, the yield of the target compound is very low or cannot be synthesized.

[Relationship between the present invention and the prior art]
As described above, the present invention can provide an imidazole compound that cannot be synthesized by a conventional method.
The imidazole compound which cannot be synthesized by the synthesis methods disclosed in Patent Document 1 and Patent Document 2 is described so that it can be clearly produced even by a person skilled in the art taking into account the common general knowledge at the time of filing this application. Therefore, the imidazole compound which cannot be synthesized described in Patent Document 1 and Patent Document 2 cannot be a “cited invention” for the present invention.
In addition, according to a judicial example (Heisei 11 (Gyo-ke) 285), "... If the invention is incomplete or cannot be implemented for some reason, it is assumed that it already exists. As a matter of course, it cannot be used as a criterion for judging novelty. In that sense, in order to become “an invention described in a distributed publication”, the invention can be carried out by those skilled in the art. It can be said that it needs to be something. ... "is judged. Even when considered based on this judicial example, the imidazole compound described in Patent Document 1 and Patent Document 2 that cannot be synthesized cannot be a “cited invention”.
A similar judgment exists in the United States (In re WIGGINS, CCPA 1973), and a similar judgment exists in Europe (T206 / 83 (0J1987, 5)).

Claims (15)

In the following general formula (1), an imidazole compound wherein R ₁ represents a substituent having a steric parameter (Es) value of −2.0 or less.

(However, in the general formula (1),
Z ₁ represents an atomic group necessary for forming a hydrocarbon ring group or a heterocyclic group, and the hydrocarbon ring group or the heterocyclic group formed in Z ₁ represents one or more of R ₁ Have
R ₂ and R ₃ represent a bond, a hydrogen atom or an aromatic hydrocarbon group, and are bonded to each other to form a 5-membered hydrocarbon ring, a 6-membered hydrocarbon ring, a 5-membered heterocycle or a 6-membered heterocycle. A ring may be formed, and these rings may have a substituent,
Z ₂ represents an atomic group necessary to form a 5-membered hydrocarbon ring, a 6-membered hydrocarbon ring, a 5-membered heterocyclic ring or a 6-membered heterocyclic ring together with C—C;
R ₄ represents a hydrogen atom or a substituent,
m represents an integer of 1 to 5. ) In the imidazole compound according to claim 1,
R ₁ represents a substituent having a steric parameter (Es) value of −2.5 or less. An imidazole compound, wherein: In the imidazole compound according to claim 1,
R ₁ represents a substituent having a steric parameter (Es) value of −3.0 or less. An imidazole compound, wherein: In the imidazole compound according to claim 1,
The R ₁ represents a substituent having a steric parameter (Es) value of −5.0 or less. In the imidazole compound according to any one of claims 1 to 4,
R ₁ represents a substituent having a molecular weight of 43 or more. An imidazole compound. In the imidazole compound according to any one of claims 1 to 4,
R ₁ represents a substituent having a molecular weight of 77 or more. In the imidazole compound according to any one of claims 1 to 4,
The R ₁ represents a substituent having a molecular weight of 116 or more. In the imidazole compound according to any one of claims 1 to 4,
R ₁ represents a substituent having a molecular weight of 166 or more. It has the imidazole compound as described in any one of Claim 1 to 8 as a partial structure. The imidazole compound characterized by the above-mentioned. It has the imidazole compound as described in any one of Claim 1 to 8 as a partial structure. The organometallic complex characterized by the above-mentioned. The organometallic complex according to claim 10,
An organometallic complex comprising at least one metal element selected from the group 8 to group 11 of the periodic table. It contains at least one of the imidazole compound according to any one of claims 1 to 8, the imidazole compound according to claim 9, and the organometallic complex according to claim 10 or 11. An organic electroluminescent element material characterized by the above. Having a plurality of organic compound layers including a light emitting layer between an anode and a cathode;
At least 1 layer of the said organic compound layer contains the organic electroluminescent element material of Claim 12. The organic electroluminescent element characterized by the above-mentioned. A display device comprising the organic electroluminescence element according to claim 13. An illuminating device comprising the organic electroluminescence element according to claim 13.