JP5968214B2 - Method for producing dihalopolycyclic aromatic compound - Google Patents

Description

The present invention relates to a method for producing a dihalopolycyclic aromatic compound useful as an intermediate of an organic synthetic compound, particularly as an intermediate of an organic electroluminescent material.

  A useful intermediate is known in a method for synthesizing a dicarbazolyl polycyclic aromatic compound having a symmetrical form in which two carbazoyl groups are substituted. For example, in the case of dibenzofuran, 2,7-dibromodibenzofuran or 2,7-diiododibenzofuran can be used as a synthetic intermediate (see, for example, Non-Patent Document 1).

  However, when synthesizing a dicarbazolyl polycyclic aromatic compound having an asymmetric form, it is difficult to control the reaction by using these intermediates, and simultaneously with 2-carbazolyl-7-halodibenzofuran substituted with only one carbazoyl group There was a problem that a product obtained by substituting two carbazoyl groups was produced as a by-product, resulting in a significant decrease in yield, and a complicated treatment such as a column was required during purification, which was not suitable for mass production.

Kryska Anna et al. , J .; Chem. Res. Miniprint. 10; 2501-2517 (1999)

Accordingly, the present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a method for producing a dihalopolycyclic aromatic compound having a high yield and being compatible with quantitative synthesis.

  The above problem could be solved by the following configuration.

  1. A method for producing a dihalopolycyclic aromatic compound, comprising producing a compound represented by the general formula [2] by brominating a compound represented by the following general formula [3].

(Wherein, R _1, R ₂ represents a substituent, n1, n2 is .X represents an integer of 0 to 3 represents an oxygen atom, a sulfur atom or _{N-C 6 H 5, N} -CH 3.)

(Wherein, R _1, R ₂ represents a substituent, n1, n2 is .X represents an integer of 0 to 3 represents an oxygen atom, a sulfur atom or _{N-C 6 H 5, N} -CH 3.)

A dihalopolycyclic aromatic compound useful as an intermediate of an organic synthetic compound, particularly as an intermediate of an organic electroluminescent material, is obtained in a high yield by the production method of the present invention, and has quantitative synthesis compatibility.

  Hereinafter, the present invention will be described in more detail.

In the general formula [1], general formula [2], general formula [3], general formula [4] and general formula [5], examples of the substituents represented by R ₁ and R ₂ include alkyl and cycloalkyl. Alkenyl, aryl, acylamino, sulfonamido, alkylthio, arylthio, halogen atom, heterocycle, sulfonyl, sulfinyl, phosphonyl, acyl, carbamoyl, sulfamoyl, cyano, alkoxy, aryloxy, heterocyclicoxy, siloxy, acyloxy, carbamoyloxy, Examples include amino, alkylamino, imide, ureido, sulfamoylamino, alkoxycarbonylamino, alkoxycarbonylamino, aryloxycarbonylamino, alkoxycarbonyl, aryloxycarbonyl, carboxyl and the like.

  X represents an oxygen atom, a sulfur atom or an imino group. Of these, preferred is an oxygen atom.

Examples of aromatic heterocycles represented by Z ₁ and Z ₂ include furan ring, thiophene ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, benzimidazole ring, oxadiazole ring, triazole ring, imidazole Ring, pyrazole ring, thiazole ring, indole ring, benzimidazole ring, benzothiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, carbazole ring, carboline ring, diazacarbazole ring (hydrocarbons constituting carboline ring) A ring in which one of the carbon atoms of the ring is further substituted with a nitrogen atom).

Examples of the aromatic hydrocarbon ring represented by Z ₁ and Z ₂ include benzene ring, biphenyl ring, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, o-tell. Phenyl ring, m-terphenyl ring, p-terphenyl ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, naphthacene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyrene ring, pyranthrene ring, Anthraanthrene rings and the like can be mentioned.

  Any of the above groups may be further substituted with a substituent. Examples of the substituent include alkyl, cycloalkyl, alkenyl, aryl, acylamino, sulfonamido, alkylthio, arylthio, halogen atom, heterocycle, sulfonyl, Sulfinyl, phosphonyl, acyl, carbamoyl, sulfamoyl, cyano, alkoxy, aryloxy, heterocyclic oxy, siloxy, acyloxy, carbamoyloxy, amino, alkylamino, imide, ureido, sulfamoylamino, alkoxycarbonylamino, alkoxycarbonylamino, Examples include aryloxycarbonylamino, alkoxycarbonyl, aryloxycarbonyl, carboxyl and the like.

  Hereinafter, representative specific examples of the compounds represented by the general formula [1], the general formula [2], the general formula [3], the general formula [4], and the general formula [5] according to the present invention will be shown. The invention is not limited to these.

  The compound represented by the general formula [2] can be obtained by reacting the general formula [1] with an iodinating agent and a brominating agent. Although there is no restriction | limiting in particular as an order, It is preferable to brominate after iodinating.

  Examples of the iodinating agent include iodine, sodium iodide, potassium iodide, hydroiodic acid, iodobenzene diacetate, iodosylbenzene, iodoylbenzene, Dess-Martin periodinane, iodate, and the like. Of these, preferred are iodobenzene diacetate and iodate, and more preferred is iodobenzene diacetate.

  Examples of the brominating agent include bromine, bromate, perbromate, phosphorus tribromide, pyridinium perbromide, N-bromosuccinimide, 1,3-dibromo-5,5-dimethylhydantoin, and the like. . Of these, preferred are bromine and bromate, and more preferred is bromine.

  The compound represented by the general formula [5] can be obtained by the reaction of the compound represented by the general formula [2] and the compound represented by the general formula [4] in the presence of a transition metal catalyst. The amount of the compound represented by the general formula [4] is preferably used in the range of 0.8 to 11 mol with respect to 1 mol of the compound represented by the general formula [2], but 0.85 to 0.95 mol. It is particularly preferable to use in this range.

  Preferred examples of the transition metal catalyst include copper powder, cuprous oxide, cuprous acetate, cupric iodide, nickel chloride, and palladium acetate. More preferred is copper powder. The addition amount is preferably 0.1 to 10 mol with respect to 1 mol of the compound represented by the general formula [2], but particularly preferably 0.5 to 3 mol.

  Examples of the reaction solvent used include alcohol, acetone, water, and aprotic solvent. Of these, DMF and DMAc are preferred.

  The reaction temperature is usually preferably from 100 to 160 ° C, particularly preferably from 130 to 150 ° C.

  The dihalopolycyclic aromatic compound represented by the general formula [2] and the pyrrolyl polycyclic aromatic compound represented by the general formula [5] of the present invention are particularly useful as intermediates for organic electroluminescent materials. As described in claim 5, the dihalopolycyclic aromatic compound represented by the general formula [2] is also an intermediate of the pyrrolyl polycyclic aromatic compound represented by the general formula [5]. The dihalopolycyclic aromatic compound represented by the general formula [2] and the intermediate of the pyrrolyl polycyclic aromatic compound represented by the general formula [5], more specifically, the light emitting layer in the organic electroluminescent material It is useful as an intermediate of a host compound used in a hole blocking layer.

  Below, the synthesis example of the host compound which uses the pyrrolyl polycyclic aromatic compound represented by General formula [5] as an intermediate body is shown.

Example Compound 5-1, 12 g (0.0291 mol), Compound A, 10.8 g (× 1.0 mol), fine powdered potassium carbonate 6.0 g (× 1.5 mol), DMSO, 200 ml were mixed, and then the system was mixed. Replacement with nitrogen flow for 20 minutes. Subsequently, 1.19 g (× 0.05 mol) of PdCl ₂ dppf was added, and the mixture was heated and stirred for 2 hours (internal temperature: 75 to 80 ° C.). After cooling to room temperature, 4 ml of well water was added. The crystals precipitated by stirring at room temperature were filtered under reduced pressure.

  It was dissolved in 200 ml of toluene and passed through a flash column packed with silica gel to remove insoluble matters. Subsequently, the solvent was removed by distillation under reduced pressure. Ethyl acetate was added to the obtained crystals, and the suspension was refluxed for 30 minutes. The mixture was stirred for 1 hour under ice-water cooling and then filtered under reduced pressure. Further, the same operation was repeated to obtain 12.5 g of Compound B. (Yield 75.0%)

  EXAMPLES The present invention will be specifically described below with reference to examples, but the embodiments of the present invention are not limited to these examples.

Example 1
<< Synthesis of Exemplified Compound 5-1 >>: Comparison

  2,7-dibromodibenzofuran 6.29 g (0.0193 mol), carbazole 2.9 g (× 0.9 mol), potassium carbonate 4.0 g (× 1.5 mol), Cu powder 3.68 g (× 3 mol), dry DMAc 75 ml And stirred for 16 hours under a nitrogen stream (internal temperature: 135 to 137 ° C.).

The insoluble matter was filtered under reduced pressure, the filtrate was extracted with THF, and the solvent was removed by distillation under reduced pressure. Purification by column chromatography (filler: silica gel, developing solution: toluene / n-hexane) gave 1.2 g of Exemplified Compound 5-1. (Yield 15%)
<< Synthesis of Exemplary Compound 5-1 >>

Illustrative compound 2-1, 7.9 g ( 0.0212 mol ), carbazole 2.9 g (× 0.9 mol), potassium carbonate 4.0 g (× 1.5 mol), Cu powder 3.68 g (× 3 mol), dry DMAc 75 ml And stirred for 16 hours under a nitrogen stream (internal temperature: 135 to 137 ° C.).

Insoluble matter was filtered under reduced pressure. 15 ml of well water was added to the filtrate, and the precipitated crystals were filtered under reduced pressure. A mixture of 11 ml of toluene and 22 ml of acetonitrile was added to the obtained crystals, and the suspension was refluxed for 30 minutes on an oil bath. The mixture was further stirred for 1 hour under cooling with ice water and then filtered under reduced pressure to obtain 3.7 g of Exemplified Compound 5-1. (Yield 51.2%)
In the comparative production method, a product in which two carbazoyl groups are substituted is also produced, so that purification is troublesome and the synthesis yield is also low. On the other hand, in the production method of the present invention, there is no formation of two substituted carbazoyl groups, purification is easy, and the yield is high.

Example 2
<< Synthesis of Exemplary Compound 3-1 >>

Exemplary compound 1-1, 30 g (0.178 mol), acetic acid 340 ml, acetic anhydride 60 ml, iodobenzene diacetate 26.1 g (× 0.455 mol) were mixed and dissolved by stirring. To this solution, 20.6 g (× 0.455 mol) of iodine and 0.5 ml of sulfuric acid were alternately added in 10 minutes. The mixture was further stirred for 2 hours.

The precipitated crystals were filtered under reduced pressure. 100 ml of ethanol was added to the obtained crystals and suspended and refluxed for 30 minutes. After stirring at room temperature for 1 hour, filtration under reduced pressure was performed to obtain Exemplified Compound 3-1, 15.9 g. (Yield 30.4% )
<< Synthesis of Exemplary Compound 2-1 >>

  Exemplified Compound 3-1, 10 g (0.034 mol) and 200 ml of acetic acid were mixed, 10.9 g (× 2 mol) of bromine was added dropwise at around 50 ° C. over 10 minutes, and the mixture was further stirred for 16 hours. (Internal temperature 65 to 66 ° C.) The mixture was stirred at room temperature for 1 hour and filtered under reduced pressure.

The obtained crystals were added to a THF / methanol mixture and suspended and refluxed for 30 minutes. After stirring at room temperature for 1 hour, it filtered under reduced pressure and obtained Exemplified Compound 2-1, 7.9 g. (Yield 62.2%)
Each compound in the examples was identified by MASS and NMR spectra to confirm that it was the target compound. Other exemplary compounds according to the general formulas [2] and [5] can also be synthesized according to the above-described method.

Claims (1)

A method for producing a dihalopolycyclic aromatic compound, comprising producing a compound represented by the general formula [2] by brominating a compound represented by the following general formula [3].
(Wherein, R _1, R ₂ represents a substituent, n1, n2 is .X represents an integer of 0 to 3 represents an oxygen atom, a sulfur atom or _{N-C 6 H 5, N} -CH 3.)
(Wherein, R _1, R ₂ represents a substituent, n1, n2 is .X represents an integer of 0 to 3 represents an oxygen atom, a sulfur atom or _{N-C 6 H 5, N} -CH 3.)