Method for preparing 4,4'-di(4-aminophenoxy)-3,3',5,5'-tetramethylbiphenyl

Abstract

The invention relates to a preparation method of 4, 4'-dia(4-aminophenoxy)-3, 3', 5, 5'-tetramethylbenzene, which comprises that 3, 3', 5, 5'- tetramethyl-4', 4'-biphenyl diphenol, and 4- halogenated nitrobenzene, in salt forming agents, strongly polar protonic or water insoluble organic solvent system, are heated, refluxed and divided, concentrated , cooled, and added with water, while the product is precipitated, filtered, washed, and dried to obtain 4, 4'-dia(4-aminophenoxy)-3, 3', 5, 5'-tetramethylbenzene, and the 4, 4'-dia(4-aminophenoxy)-3, 3', 5, 5'-tetramethylbenzene in the reduction system of ferric chloride / 20-85% hydrazine hydrate, the cooperation of alcohol solvent and active carbon, is reacted to obtain final product. The invention has simple and environment-friend operation, which can be used for industrialization production, while the product can reach more than 99% of purity, and the solvent can be reclaimed.

Description

technical field [0001] The invention belongs to the field of preparation of aromatic dibasic primary amines, in particular to the preparation of 4,4'-bis(4-aminophenoxy)-3,3',5,5'-tetramethylbiphenyl method. Background technique [0002] Aromatic polyimide has excellent thermal stability, nuclear radiation resistance, excellent mechanical properties, electrical properties and resistance to organic solvents, and has been widely used in aerospace, electronic microelectronics, electrical and other fields. [0003] With the development of high-performance, lightweight, thin, and refined information electronic products, higher requirements are put forward for the insulation materials of flexible copper clad laminates (FCCL), such as high heat resistance, low dielectric loss, and high strength. Wait. Therefore, polyimide materials have attracted much attention in the field of FCCL, especially thermoplastic polyimide materials used in two-layer FCCL. [0004] Aromatic primary di...

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Problems solved by technology

[0020] The shortcoming of this preparation method is: (1) organic solvent recovery is difficult in the whole preparation process, is unfavorable for environmental protection; , In the process of 5,5'-tetramethylbiphenyl, the reaction mixture is directly poured into the mixture of methanol and water to precipitate the product, resulting in serious waste water and high treatment costs, which is not conducive to environmental protection; (3) organic solvent recovery Difficulty; (4) 4,4'-bis(4-nitrophenoxy)-3,3',5,5'-tetramethylbiphenyl obtained by synthesis also needs to be recrystallized through DMF, which not only increases cost, but also additionally produced three wastes; (5) the use of 10% Pd / C in the reduction reaction leads to an increase in product cost, which is not conducive to commercial production; (6) the 4,4'-bis(4- Aminophenoxy)-3,3',5,5'-tetramethylbiphenyl also needs to be washed with water, which not only increases the cost, but also produces three wastes; (7) the first step and the second step The yield is low, resulting in a lower total yield, only 74%*72%=53.28%

[0022] The shortcoming of this preparation method is: (1) the yield of 4,4'-bis(4-nitrophenoxy)-3,3',5,5'-tetramethylbiphenyl is only 78%, which is low (2) the reduction reaction needs to be carried out under high temperature and high pressure conditions, which requires high equipment and has certain dangers; (3) the use of noble metal catalysts increases the cost of the product, which is not conducive to commercial production; (4) reduction The use of hydrogen in the reaction has certain safety risks; (5) 4,4'-bis(4-aminophenoxy)-3,3',5,5'-tetramethylbiphenyl melting point (203- 205℃) is low, indicating that the purity is low

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