Preparation method of p-hydroxyacetophenone

A technology of p-hydroxyacetophenone and chlorobenzene, which is applied in the field of preparation of p-hydroxyacetophenone, can solve the problems of unfavorable industrial application, complicated preparation method, and many by-products, achieve good production and application prospects, increase production volume, The effect of increasing productivity

Pending Publication Date: 2020-04-24
老河口瑞祥化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] At present, the simplest process for synthesizing p-hydroxyacetophenone mostly adopts phenol as a raw material, utilizes acetyl chloride as an acetylation reagent, and uses Lewis acid as a catalyst to generate para- and ortho-hydroxyacetophenone through Fries rearrangement reaction. The process step of this method is simple, but o-hydroxyacetophenone is not target product, in order to improve the yield of p-hydroxyacetophenone, need to reduce the yield of o-hydroxyacetophenone as far as possible, although other production methods can be to a certain extent Improve the yield, but most of the preparation methods are more complicated, or there are more by-products, and the pollution is more serious, which is not conducive to industrial application

Method used

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  • Preparation method of p-hydroxyacetophenone

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Comparison scheme
Effect test

Embodiment 1

[0026] Take a 5L three-necked bottle, weigh 1120g chlorobenzene, 1000g acetyl chloride and 10g aluminum chloride respectively, put the chlorobenzene and aluminum chloride into the three-necked bottle, and place it in a freezing tank, control the temperature below 10°C, and put 1000g Acetyl chloride was slowly added dropwise to the three-necked flask, and the dropping time was 3 hours. After the dropwise addition, the three-necked bottle was placed in a water bath, heated to 60°C, and kept for 2 hours. After the insulation was completed, the reaction system was filtered to obtain the filtrate. Alkali was configured into 10% sodium hydroxide aqueous solution, mixed sodium hydroxide aqueous solution and filtrate, transferred to a 10L three-necked flask, heated to 120°C in an oil bath, and refluxed for 4 hours. After the reaction was completed, hydrochloric acid was added dropwise to adjust the pH to 3.12. Stir and stand for stratification, take the organic layer, heat up to 125°C,...

Embodiment 2

[0028] Take a 5L three-neck bottle, weigh 1120g chlorobenzene, 1200g acetyl chloride and 20g zinc chloride respectively, put the chlorobenzene and zinc chloride into the three-necked bottle, and place them in a freezing tank, control the temperature below 10°C, and put 1200g Acetyl chloride was slowly added dropwise to the three-necked flask, and the dropping time was 3.5 hours. After the dropwise addition, the three-necked bottle was placed in a water bath, and the temperature was raised to 80°C, and the reaction was kept for 3 hours. The caustic soda is configured into a 20% sodium hydroxide aqueous solution, and the sodium hydroxide aqueous solution is mixed with the filtrate, transferred to a 10L three-necked bottle, heated to 150°C in an oil bath, and refluxed for 8 hours. After the reaction is completed, add hydrochloric acid dropwise to adjust the pH to 5.05 , stir and stand for stratification, take the organic layer, heat up to 130°C, distill, until there is no obvious ...

Embodiment 3

[0030] Take a 5L three-necked bottle, weigh 1120g chlorobenzene, 1100g acetyl chloride and 15g ferric chloride respectively, put chlorobenzene and ferric chloride into the three-necked bottle, and place them in a freezing tank, control the temperature below 10°C, and put 1100g Acetyl chloride was slowly added dropwise to the three-necked flask, and the dropping time was 3 hours. After the dropwise addition, the three-necked bottle was placed in a water bath, and the temperature was raised to 70°C, and the reaction was kept for 2.5 hours. The caustic soda is configured into a 15% sodium hydroxide aqueous solution, and the sodium hydroxide aqueous solution and the filtrate are mixed, transferred to a 10L three-necked bottle, heated to 130°C in an oil bath, and refluxed for 6 hours. After the reaction is completed, add hydrochloric acid dropwise to adjust the pH to 4.26 , stirring and standing for stratification, take the organic layer, heat up to 128°C, distill, until there is no...

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Abstract

The invention provides a preparation method of p-hydroxyacetophenone. Chlorobenzene and acetyl chloride are used as reaction substrates; a Fries rearrangement reaction; acetyl is connected to the para-position of chlorobenzene; chlorine substituents on a benzene ring are hydrolyzed to hydroxyl groups by hydrolysis reaction, and thus the target product is obtained. The preparation method provided by the invention overcomes the problem of more byproducts o-hydroxyacetophenone in a conventional technology, and has the advantages of simple process, fewer types of used raw materials, no excessive discharge of three wastes in the post-treatment process, and good production and application prospects.

Description

technical field [0001] The invention relates to the technical field of chemical synthesis, in particular to a preparation method of p-hydroxyacetophenone. Background technique [0002] p-Hydroxyacetophenone is an important chemical intermediate and raw material, which has been widely used in various fields. It can be used as a raw material for drug synthesis, and can also be used as an excellent preservative. It has excellent Mildness, so it is an important chemical raw material. [0003] At present, the simplest process for synthesizing p-hydroxyacetophenone mostly adopts phenol as a raw material, utilizes acetyl chloride as an acetylation reagent, and uses Lewis acid as a catalyst to generate para- and ortho-hydroxyacetophenone through Fries rearrangement reaction. The process step of this method is simple, but o-hydroxyacetophenone is not target product, in order to improve the yield of p-hydroxyacetophenone, need to reduce the yield of o-hydroxyacetophenone as far as po...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C45/46C07C49/807C07C45/64C07C45/78C07C45/82C07C45/81C07C49/825
CPCC07C45/46C07C45/64C07C45/78C07C45/82C07C45/81C07C49/807C07C49/825
Inventor 张旭黄春节
Owner 老河口瑞祥化工有限公司
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