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Method for preparing 4,6-diaminoresorcinol hydrochloride

A technology of diaminoresorcinol hydrochloride and dinitroresorcinol, which is applied in 4 fields, can solve the problem that the purity cannot meet the requirements of PBO fiber synthesis, and achieve the effect of reducing the generation of by-products and isomers

Active Publication Date: 2010-09-29
HEBEI JIANXIN CHEM IND CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is to provide a preparation method of 6-diaminoresorcinol hydrochloride, which overcomes the problem that the purity of the product obtained by the existing preparation technology cannot meet the requirements of PBO fiber synthesis, and improves the resorcinol hydrochloride. The low-temperature sulfonation and nitration reaction of phenol in the oleum system reduces the generation of by-products and isomers, making the purity of the intermediate 4,6-dinitroresorcinol reach 99.9%, and the yield reaches 82%, guaranteed to be able to produce high-purity 4,6-diaminoresorcinol hydrochloride

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Add 100g of 30wt% oleum into a 500ml reactor, raise the temperature to between 80°C and 90°C, start adding 11g of resorcinol slowly, and keep it warm for 4-8 hours. Cool down to 40°C~50°C with ice after the heat preservation is completed, then add 21g of 60% nitric acid dropwise to the sulfonation solution, the reaction is exothermic violently, cool down with cold water, the reaction temperature is controlled at 40°C~50°C, and the heat preservation reaction is 4~10 After the reaction is completed, slowly add the nitration reaction solution into 200g of water to dilute, and carry out the hydrolysis reaction at 100°C for 6-9 hours, the reaction gradually precipitates crystals, and 16.04g of 4,6-dinitro Resorcinol, the yield is 80.3% and the purity is 99.91%.

Embodiment 2

[0030] Add 1000g of 30wt% oleum into a 3000ml reactor, raise the temperature to between 80°C and 90°C, slowly add 110g of resorcinol, and keep warm for 4-8 hours. After the heat preservation is completed, use ice cooling to cool down to 40°C~50°C, then add 210g of 60% nitric acid dropwise to the sulfonation solution, the reaction is exothermic violently, cool down with cold water, and the reaction temperature is controlled at 40°C~50°C and keep the temperature for 4~10 hours. After the reaction, the nitration reaction solution was slowly added to 2000g of water for dilution, and hydrolyzed at 100°C for 6 to 9 hours. Crystals gradually precipitated during the reaction, and 162.4g of 4,6-dinitroisophthalic acid was obtained by filtration. Phenol, the yield is 81.2%, and the purity is 99.95%.

Embodiment 3

[0032] Add 40g of 4,6-dinitroresorcinol prepared in Example 1 or 2 in the hydrogenation kettle, add 200g of methanol, then add 0.396g of 5% palladium carbon, then replace with nitrogen 4 times, then replace with hydrogen 4 times, heat up to 50°C~60°C, then pass in hydrogen to make the reaction pressure reach 0.5~0.8Mpa, react for 2~4 hours, cool down to 20°C, pour the reactant into 5% tin chloride containing 2000ppm In the hydrochloric acid solution of tin protochloride, remove catalyst by filtration, then remove solvent with evaporator, cool down to obtain crude product 21.3g, this crude product crystal is dissolved in the hydrochloric acid solution of tin protochloride, adds activated carbon decolorization 30 minutes, removes activated carbon by filtration. 160g of 36% hydrochloric acid was added dropwise to the filtrate to obtain white crystals, which were filtered and dried under reduced pressure to obtain 19.72g of 4,6-diaminoresorcinol hydrochloride with a yield of 46.4% ...

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Abstract

The invention relates to a preparation method of 4, 6-diamino resorcinol hydrochloride, which comprises sulfonating, nitrating and hydrolyzing resorcinol to obtain intermediate 4, 6-dinitro resorcinol, processing hydrogenation reduction on the intermediate to obtain 4, 6-diamino resorcinol hydrochloride, wherein the product purity can satisfy PBO fiber synthesis. The invention avoids processing low-temperature sulfonation and nitration of resorcinol in fuming sulfuric system, thereby reducing the generation of byproduct and isomer, improving the purity of 4, 6-diamino resorcinol hydrochlorideto 99.9% and improving yield to 82%, to confirm the preparation of high-purity 4, 6-diamino resorcinol hydrochloride.

Description

technical field [0001] The invention relates to a preparation method of 4,6-diaminoresorcinol hydrochloride. Background technique [0002] 4,6-diaminoresorcinol hydrochloride is an important monomer in the synthesis of high molecular fiber polymer polybenzoxazole (PBO). [0003] In terms of the strength, elastic modulus, heat resistance and chemical resistance of PBO fibers described in Japanese Patent 501452 / 1986, PBO fibers are superior to traditional aramid fibers, and PBO fibers will be used In various fields such as structural materials and heat-resistant materials, PBO is known as "the super fiber of the 21st century". 4,6-diaminoresorcinol hydrochloride is an important monomer for PBO, so 4,6-diaminoresorcinol hydrochloride is an important raw material for the synthesis of PBO, but the current 4,6- The purity of 4,6-diaminoresorcinol hydrochloride prepared by the preparation method of diaminoresorcinol hydrochloride cannot meet the needs of PBO fiber synthesis, and ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C215/80C07C213/02
Inventor 朱秀全朱守琛马增宝
Owner HEBEI JIANXIN CHEM IND CO LTD
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