N,N'-bi(3-methylphenyl)-N,N'-diphenylbenzidine preparation method

Abstract

The invention relates the preparing method of N, N'- 3-methyl phenyl)-N, N' -diphenylbenzidine, belonging to organic semiconductor hole transport material preparing technique field. The method comprises the following steps: using halogeno-benzene and 3- methyl diphenylamine as raw material, using toluene as dissolvant, using cuprous iodide with N-dimethyltoluamide or diphyridyl as accelerating agent, carrying out reaction in the potassium hydrate system, decolouring, washing, drying, distilling, getting bullion, purifying with the mixture of toluene, hexane and methanol, getting the product. The invention has the advantages of reducing cost, and improving quality. The product can be used as the key material of organic photoconductive drum.

Description

technical field [0001] The invention relates to a preparation method of N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine, which belongs to the technical field of preparation of organic semiconductor hole transport materials. Background technique [0002] N,N'-bis(3-methylphenyl)-N,N'-diphenylbenzidine can be used in the preparation and industrial production of electroluminescent devices, organic photoconductive devices, etc. due to its unique free radical properties , is an important part of organic photoelectric conversion devices. [0003] According to the report of relevant literature, the preparation of N, N'-bis(3-methylphenyl)-N, N'-diphenylbenzidine mainly contains following kinds: [0004] 1. Traditional Ullmann reaction synthesis: use metal hydroxide or carbonate as the base, copper powder, copper alloy, cu(I) or cu(II) salt as the catalyst, and nitrobenzene as the solvent. Aromatic amines and aromatic halides (commonly used aromatic iodides) react. The reaction o...

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Problems solved by technology

The reaction of this system usually requires a high temperature above 200°C, a large amount of catalyst, and a reaction time of more than 20 hours to ensure a medium or higher yield. It is not suitable for the synthesis of compounds containing groups sensitive to high temperature. Under the conditions of high temperature and strong alkali, more by-products will be produced, which will cause difficulties in product separation, high cost and low efficiency

[0005] 2. Synthesis of 18-crown-6 ether as a catalyst: Gauthier et al. improved the traditional Ullmann reaction, adding crown ether (18-crown-6) as a phase transfer catalyst in the reaction system, although the yield of the reaction was greatly improved , but 18-crown-6 ether has higher solubility in water, higher price and higher toxicity

[0006] 3. Synthesis with CuI as a catalyst: Nandkumar et al. have compared the influence of different catalysts, complexes, bases, and solvents on the synthesis of triphenylamine derivatives through a large number of experiments, and finally concluded that: substituted aniline, substituted iodobenzene as Raw materials, CuI is the catalyst, 2,6-diphenylpyrimidine is the complex, KOt-Bu is the base, and toluene is the solvent. It is best to prepare triphenylamine at 115°C, but no specific raw materials are mentioned.

However, due to the disadvantages of expensive Pd, it is limited in application, and due to factors such as expensive organic palladium catalysts, narrow activity temperature range, easy deactivation, and difficulty in preparing the required special ligands, it is not suitable for product productivity. Preparation, currently can not replace the Ullmann-type reaction status

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