Preparation method of 2,2'-bistrifluoromethyl-4,4'-diaminobiphenyl

A bistrifluoromethyl and diaminobiphenyl technology is applied in the preparation of amino compounds, the preparation of organic compounds, chemical instruments and methods, etc. It can solve problems such as difficulties in industrial production, inability to use large quantities, explosions, etc., and achieve solvent-free Effects of recycling, easy control of reaction, and simple investment

Inactive Publication Date: 2015-11-04
尚振华 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Palladium-carbon hydrogenation has certain dangers, improper operation will cause explosion, and industrial production is extremely difficult; zinc powder has strong reducing properties, and its dust and air can form an explosive mixture. When reaching a certain concentration, it will explode when it encounters sparks , cannot be used in large quantities in industrial production; tin and its organic compounds are limited to laboratory research due to their high price

Method used

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  • Preparation method of 2,2'-bistrifluoromethyl-4,4'-diaminobiphenyl

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Add 76kg of 2,2'-bistrifluoromethyl-4,4'-dinitrobiphenyl to the reaction kettle and dissolve it in 608kg of methanol, then add 32kg of anhydrous ferric chloride, and heat up to 50°C under stirring. Add dropwise 95kg of 80% hydrazine hydrate (the molar ratio is: 2,2'-bistrifluoromethyl-4,4'-dinitrobiphenyl:ferric chloride:80% hydrazine hydrate:methanol=1:1.09: 8:80), the dropping temperature remained basically unchanged, after the dropping was completed, the temperature was raised to reflux, and after the reaction of the raw materials was completed, the temperature was lowered to room temperature, filtered, the filtrate was depressurized and the solvent was recovered, and the crystal was precipitated, cooled and filtered, and dried to obtain 2,2' - Bistrifluoromethyl-4,4'-diaminobiphenyl 55.3 kg, off-white solid, yield 91%.

Embodiment 2

[0018] Add 76kg 2,2'-bistrifluoromethyl-4,4'-dinitrobiphenyl to the reaction kettle and dissolve it in 570kg methanol, then add 31.4kg anhydrous ferric chloride, and heat up to 45 ℃, drop 71kg 80% hydrazine hydrate (molar ratio: 2,2'-bistrifluoromethyl-4,4'-dinitrobiphenyl:ferric chloride:80% hydrazine hydrate:methanol=1: 1.02:6:75), the dropping temperature remains basically unchanged, after the dropwise addition is completed, the temperature is raised to reflux, and after the reaction of the raw materials is complete, the temperature is lowered to room temperature, filtered, the filtrate is decompressed and the solvent is recovered, the crystal is precipitated, and the temperature is filtered, and dried to obtain 2, 43.8 kg of 2'-bistrifluoromethyl-4,4'-diaminobiphenyl, off-white solid, yield 72%.

Embodiment 3

[0020] Add 76kg 2,2'-bistrifluoromethyl-4,4'-dinitrobiphenyl to the reaction kettle and dissolve it in 650kg of methanol, then add 35.7kg of anhydrous ferric chloride, and heat up to 50 ℃, drop 115kg 80% hydrazine hydrate (the molar ratio is: 2,2'-bistrifluoromethyl-4,4'-dinitrobiphenyl: ferric chloride: 80% hydrazine hydrate: methanol=1: 1.16:10:85), the dropping temperature remains basically unchanged, after the dropwise addition is completed, the temperature is raised to reflux, and after the reaction of the raw materials is complete, the temperature is lowered to room temperature, filtered, the filtrate is decompressed and the solvent is recovered, the crystal is precipitated, and the temperature is filtered, and dried to obtain 2, 56.1 kg of 2'-bistrifluoromethyl-4,4'-diaminobiphenyl, off-white solid, yield 92.3%.

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Abstract

The invention relates to a preparation method of 2,2'-bistrifluoromethyl-4,4'-diaminobiphenyl. The preparation method comprises the steps: dissolving 2,2'-bistrifluoromethyl-4,4'-dinitrobipheny in a polar protic solvent, then adding a catalyst, heating up to 40-60 DEG C, dropwise adding 80% hydrazine hydrate, next heating up to carry out a reflux reaction, after the raw materials are subjected to complete reaction, cooling down to room temperature, filtering, distilling a solvent out of the filtrate, and precipitating a 2,2'-bistrifluoromethyl-4,4'-diaminobiphenyl crystal. By-products of the method adopting hydrazine hydrate for reduction are nitrogen and water, and substances harmful to the environment do not produced; moreover, the method has the advantages of simple reaction device investment, easy control of the reaction, recycled solvent, high yield, repeatability and the like. In today, concerns on ecology and environment are grown, and the method can become a supplement of a catalytic hydrogenation method and replaces a partial sodium sulfide reduction method and a metal reduction method.

Description

technical field [0001] The invention relates to a preparation method of an intermediate 2,2'-bistrifluoromethyl-4,4'-diaminobiphenyl which can be used as a polyimide resin material. Background technique [0002] 2,2′-bistrifluoromethyl-4,4′-diaminobiphenyl is a key intermediate in the synthesis of polyimide monomer materials. As a special engineering material, polyimide has been widely used in aviation, microelectronics, nanometer, liquid crystal, separation membrane, laser and other fields. Because of its outstanding features in performance and synthesis, its huge application prospects, whether as structural materials or as functional materials, have been fully recognized. [0003] The most direct preparation method of 2,2′-bistrifluoromethyl-4,4′-diaminobiphenyl is the reduction of 2,2′-bistrifluoromethyl-4,4′-dinitrobiphenyl Response gets. In the literature, the reduction methods of 2,2′-bistrifluoromethyl-4,4′-diaminobiphenyl are basically divided into two categories:...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C211/52C07C209/36
Inventor 尚振华栗晓东
Owner 尚振华
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