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Method for synthesizing p-hydroxyacetophenone

A technology for p-hydroxyacetophenone and a synthesis method, which is applied in the field of synthesis of p-hydroxyacetophenone, can solve the problems of complicated post-treatment, unfriendly environment, etc., and achieves the effects of being environmentally friendly, simple in method, and high in industrialized production value.

Active Publication Date: 2019-02-26
SUZHOU KAIYUAN MINSHENG SCI & TECH CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The method used 1.38 molar equivalents of acetic anhydride and a large excess of AlCl 3 , the post-processing is complex and the environment is not friendly

Method used

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  • Method for synthesizing p-hydroxyacetophenone
  • Method for synthesizing p-hydroxyacetophenone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Chlorobenzene (1125.6g) was added in a 2L four-necked flask, and aluminum trichloride (294g, 2.2mol, 1.1q) was added in batches, then the temperature was raised to 50°C, and acetic anhydride (204g, 2mol, 1.0eq) was added slowly Slowly drop it into the reactor, control the temperature of the reaction solution at 50°C to 55°C, and finish the drop in about 1.5hr. The temperature was later raised to ~75°C for 4hrs. The reaction is over. Slowly pour the reaction solution into a 1 kg ice-water bath, control the internal temperature -5 ~ 5 ° C, after adding the feed solution, warm it up to room temperature, and separate the liquids. The organic phase reclaimed 900 g of chlorobenzene, and then rectified to obtain 272 g of p-chloroacetophenone, with a yield of 88% and 18.6 g of o-chloroacetophenone, with a yield of 6% (the yield was calculated based on the chlorobenzene consumed by the reaction).

[0037] In a 2L autoclave, add 1000g of 30% sodium hydroxide solution, and then ...

Embodiment 2

[0039] Chlorobenzene (1125.6g) was added in a 5L four-necked flask, and aluminum trichloride (647g, 4.84mol, 1.2q) was added in batches, then the temperature was raised to 50°C, and acetic anhydride (408g, 4mol, 1.0eq) was slowly Slowly drop it into the reactor, control the temperature of the reaction solution at 55°C to 60°C, and finish the drop in about 1.5hr. The temperature was later raised to ~70 °C for 4 hrs. The reaction is over. Slowly pour the reaction solution into a stirred 2.5 kg 1% hydrochloric acid bath, control the internal temperature -5 ~ 5 ℃, add the feed solution, rise to room temperature, and separate the liquids. The organic phase reclaims 448g of chlorobenzene, and then rectifies to obtain 533g of p-chloroacetophenone, with a yield of 86.2% and 35g of o-chloroacetophenone, with a yield of 5.6% (the yield is calculated by the chlorobenzene consumed by the reaction).

[0040] In a 2L autoclave, 1000 g of 50% sodium hydroxide solution was added, and then 3...

Embodiment 3

[0042] Chlorobenzene (900g) was added to a 2L four-necked flask, and aluminum chloride (387.5g, 2.9mol, 1.45q) was added in batches, then the temperature was raised to 50°C, and acetic anhydride (204g, 2mol, 1.0eq) was slowly Slowly drop it into the reactor, control the temperature of the reaction solution at 55°C to 60°C, and finish the drop in about 1.5hr. The temperature was later raised to ~70°C for 5hrs. The reaction is over. Slowly pour the reaction solution into 1.5 kg of 1% ice dilute hydrochloric acid bath, raise to room temperature, and separate the layers. The organic phase reclaims chlorobenzene 674g, rectification obtains p-chloroacetophenone 259g, yield 84% and o-chloroacetophenone 18.6g, yield 6% (calculate yield with the chlorobenzene consumed by reaction).

[0043]In a 2L autoclave, 1000 g of 45% potassium hydroxide solution was added, and then 309.2 g of p-chloroacetophenone was added, and the mixture was sealed and heated to an inner temperature of 160°C. ...

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Abstract

The invention provides a method for synthesizing p-hydroxyacetophenone. The method comprises the following steps: firstly, 4'-chloroacetophenone is synthesized from chlorobenzene and acetic anhydrideas raw materials under catalysis of a Lewis acid catalyst, and the yield is 85%-91%; secondly, 4'-chloroacetophenone is hydrolyzed in an alkaline aqueous solution at high temperature and high pressure, p-hydroxyacetophenone is precipitated after acidification and cooling, and the yield is 90%-98%. The total yield of the two-step reaction is 77%-89%. Chlorobenzene is used as a starting material tosynthesize the p-hydroxyacetophenone, phenol used as the starting material in the traditional process is discarded, so that the defects that phenol is discharged with sewage and is not environmentallyfriendly as a result of incomplete reaction are avoided, and the method has high industrial production value.

Description

technical field [0001] The invention relates to a synthesis method of p-hydroxyacetophenone, which belongs to the technical field of chemical pharmacy. Background technique [0002] 4-Hydroxyacetophenone is used in the manufacture of choleretic drugs, synthetic paracetamol, ractopamine hydrochloride, anti-preterm drugs and atenolol, etc. 4-Hydroxyacetophenone is a cosmetic raw material with the following characteristics: (1) has certain (2) strong killing ability to Aspergillus niger; (3) certain inhibitory effect on Pseudomonas aeruginosa. Therefore, the application is relatively wide. [0003] Generally, p-hydroxyacetophenone adopts esterification reaction and Fries rearrangement reaction. With phenol and acetic anhydride as the main raw materials, phenol acetate can be conveniently prepared through esterification. Under Lewis acid catalysis, phenol acetate undergoes Fries rearrangement reaction to produce o-hydroxybenzophenone and p-hydroxyacetophenone. The following ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C45/46C07C49/807C07C45/64C07C49/825
CPCC07C45/455C07C45/46C07C45/64C07C49/807C07C49/825
Inventor 沈冰良赵飞黄忠林
Owner SUZHOU KAIYUAN MINSHENG SCI & TECH CORP
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