A kind of preparation method of high-purity p-hydroxyacetophenone

A high-purity technology for p-hydroxyacetophenone, which is applied in the field of fine chemicals, can solve the problems of complex post-processing, affecting the yield of hydroxyacetophenone, and serious environmental pollution, so as to improve selectivity and conversion rate, simplify operation, Reduce the effect of intermediate processing

Active Publication Date: 2020-07-24
SINO HIGH CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] In the products obtained by traditional methods, there are more or less a considerable part of ortho isomers, which affects the yield of p-hydroxyacetophenone, and a large amount of AlCl is used in the reaction process 3 , the direct consequence of this is that the post-processing is complicated and the environmental pollution is serious

Method used

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  • A kind of preparation method of high-purity p-hydroxyacetophenone

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Weigh 267g of AlCl respectively 3 and 4.2g of LiCl were added to 200mL of o-dichlorobenzene, and after heating to 50°C, 86g of acetyl chloride was slowly added dropwise. After the dropwise addition, 94g of phenol was added to the reaction solution, the reaction temperature was maintained, and stirring was continued for 6 hours. The HCl tail gas generated during the reaction was absorbed by water to obtain a hydrochloric acid solution, which could be applied mechanically until deicing.

[0032] After the reaction was completed, the catalyst was removed by filtration while hot. Then, 100 mL of 10% hydrochloric acid solution was added for hydrolysis, and after stirring for 0.5 h, the organic phase was separated.

[0033] The organic phase is then washed with acid, alkali, and water to remove impurities such as metal salts. The obtained organic phase was cooled to below 0°C, crystallized and filtered to obtain crude p-hydroxyacetophenone. The crude product was recrystall...

Embodiment 2

[0035] Weigh 243g of FeCl respectively 3 and 4.2g of LiCl were added to 200mL of o-dichlorobenzene, and after heating to 70°C, 86g of acetyl chloride was slowly added dropwise. After the dropwise addition, 94g of phenol was added to the reaction solution, the reaction temperature was maintained, and stirring was continued for 5 hours. The HCl tail gas generated during the reaction was absorbed by water to obtain a hydrochloric acid solution, which could be applied mechanically until deicing.

[0036] After the reaction was completed, the catalyst was removed by filtration while hot. Then, 100 mL of 10% hydrochloric acid solution was added for hydrolysis, and after stirring for 0.5 h, the organic phase was separated.

[0037] The organic phase is then washed with acid, alkali, and water to remove impurities such as metal salts. The obtained organic phase was cooled to below 0°C, crystallized and filtered to obtain crude p-hydroxyacetophenone. The crude product was recrystall...

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Abstract

The invention discloses a preparation method of high-purity p-hydroxyacetophenone. The preparation method includes the steps of: 1) performing an esterification reaction to acetyl chloride and phenol in a solvent under effects of a catalyst A and a catalyst B; 2) after the reaction is finished, replenishing a solvent to an esterification reaction liquid to dissolve and dilute the reaction product, removing the catalyst, and adding a hydrochloric acid water solution to perform a hydrolysis reaction; 3) after the hydrolysis reaction, allowing the reaction liquid to stand to layer the reaction liquid, removing a water layer, washing an organic phase and removing impurities, reducing the temperature for crystallization, and separating the solid to obtain a crude product of the p-hydroxyacetophenone. The method employs the acetyl chloride, instead of acetic anhydride, to perform the esterification reaction with phenol, thereby producing the p-hydroxyacetophenone in a one-pot manner, so that intermediate products are unnecessary to purify and intermediate treatment process is reduced, thereby simplifying operations and improving efficiency. The side product, hydrochloric acid, can be directly used in the hydrolysis reaction, so that generation of a side product, acetic acid, is avoided. Through the oriented catalysis technology, selectivity and conversion rate of the para-position are increased. The method can prepare the p-hydroxyacetophenone being higher than 99.5% in purity.

Description

technical field [0001] The invention belongs to the field of fine chemical industry, in particular to a kind of p-hydroxyacetophenone, specifically a kind of preparation method of high-purity p-hydroxyacetophenone. Background technique [0002] As a fine chemical intermediate, p-hydroxyacetophenone can be used as a pharmaceutical intermediate, such as the synthesis of paracetamol and ractopamine hydrochloride, anti-preterm drugs, atenolol, etc. In addition, p-hydroxyacetophenone, as a cosmetic raw material, was included in the 2014 "Catalog of Names of Used Cosmetic Raw Materials" by China Food and Drug Administration (CFDA). According to literature reports, p-hydroxyacetophenone has the following characteristics in cosmetics: 1. has a certain antiseptic ability; 2. has a strong ability to kill Aspergillus niger; Chemical Industry, 2015, 45:269.). Another document reports that it is compounded with 1,2-hexanediol and a traditional Chinese medicine composition; the compound...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C07C49/825C07C45/54C07C45/78C07C45/81
CPCC07C45/54C07C45/78C07C45/81C07C67/08C07C49/825C07C69/157
Inventor严留新汤浩张海娟王大胜陈年海
OwnerSINO HIGH CHINA