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Method for preparing o-hydroxyacetophenone and p-hydroxyacetophenone

A technology for p-hydroxyacetophenone and o-hydroxyacetophenone, which is applied in the field of preparation of o-hydroxyacetophenone and p-hydroxyacetophenone, can solve the problems of complicated post-treatment, serious environmental pollution and the like, and achieves mild experimental conditions, The effect of high experimental yield and good promotion and application value

Active Publication Date: 2011-06-15
曹日庆 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method uses chlorobenzene or 1,2-dichloroethane as a solvent, and the reaction temperature is 60-90°C, but a large excess of AlCl is used. 3 , complex post-processing, serious environmental pollution

Method used

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  • Method for preparing o-hydroxyacetophenone and p-hydroxyacetophenone
  • Method for preparing o-hydroxyacetophenone and p-hydroxyacetophenone

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] (1) Preparation of ethyl phenol phenol ester

[0023] Mix 9.1g of phenol and 107g of acetic anhydride in a flask evenly, place in a cold bath, and add 1 drop of concentrated sulfuric acid dropwise. Shake and cool down to room temperature, distill acetic acid under normal pressure, and then collect fractions at 194-196°C to obtain ethyl phenol phenol ester with a yield of 98% (calculated as phenol).

[0024] (2) preparation of p-hydroxyacetophenone and o-hydroxyacetophenone

[0025] Mix 74.8g of aluminum trichloride and 30.5g of phenol acetate, slowly heat to 160°C in an oil bath, and keep it warm for 2 hours. When cooled to 40-50°C, add glacial hydrochloric acid solution (220mL, 3.2mol / L) for hydrolysis, separate the organic phase, freeze, and filter to obtain crude p-hydroxyacetophenone.

[0026] The filtrate was steam distilled, and the organic phase separated from the distillate was distilled under reduced pressure to obtain a light yellow oily liquid o-hydroxyacet...

Embodiment 2

[0028] (1) Preparation of ethyl phenol phenol ester

[0029] Mix 94g of phenol with 110g of acetic anhydride, heat to reflux for 30 minutes, remove acetic acid by fractional distillation, and collect fractions at 194-196°C to obtain phenol acetate with a yield of 95% (calculated as phenol).

[0030] (2) preparation of p-hydroxyacetophenone and o-hydroxyacetophenone

[0031] Put 74.8g of aluminum trichloride in 80mL of carbon disulfide, control the speed of dropping phenol acetate (68g) under stirring, and keep the system in a slightly boiling state. After the dropwise addition, the mixture was heated under reflux in a water bath for 2 hours, then the solvent was evaporated, heated in an oil bath, and stirred at 175°C for 3 hours. After cooling to room temperature, hydrochloric acid solution (220 mL, 3.2 mol / L) was added for hydrolysis, and the organic phase was separated and subjected to steam distillation to obtain o-hydroxyacetophenone (24.5 g, 36%). The residue was extrac...

Embodiment 3

[0033] (1) Preparation of ethyl phenol phenol ester

[0034] Mix 94g of phenol with 110g of acetic anhydride, heat to reflux for 30 minutes, remove acetic acid by fractional distillation, and collect fractions at 194-196°C to obtain phenol acetate with a yield of 95% (calculated as phenol).

[0035] (2) preparation of p-hydroxyacetophenone and o-hydroxyacetophenone

[0036] Mix 60g of sodium chloride and 136g of powdered aluminum trichloride in a bottle evenly, heat to 230°C and keep for 1 hour. Add 100 g of phenol acetate dropwise within 30 minutes at about 200°C, and react at 240°C for 10 minutes after the dropwise addition is complete. Cool to room temperature, add hydrochloric acid solution (300mL, 10%) for hydrolysis, steam distillation, extract the distillate with ether, dry the extract to recover ether, then distill under reduced pressure, collect fractions at 101-105°C / 2KPa to obtain o-hydroxybenzene Ethyl ketone (42 g, 42%). The steam distillation residue was extra...

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Abstract

The invention discloses a method for preparing o-hydroxyacetophenone and p-hydroxyacetophenone. The method comprises the following steps of: reacting phenol and acetic anhydride to obtain acetic phenate, adding Lewis acid into the acetic phenate, hydrolyzing the obtained product by adopting glacial hydrochloric acid, separating an organic layer by standing, freezing and filtering the organic layer, re-crystallizing the obtained filter cakes by using water, decolorizing the crystal by using active carbon to obtain the p-hydroxyacetophenone, distilling the filtrate obtained by freezing and filtering the organic layer through water vapor, and performing reduced pressure rectification to obtain the o-hydroxyacetophenone. The method has the advantages of low raw material price, mild experiment condition and high experiment yield; the ratio of the o-hydroxyacetophenone to the p-hydroxyacetophenone can reach 1.4:1; and the method has good popularization and application values.

Description

technical field [0001] The invention relates to a preparation method of o-hydroxyacetophenone and p-hydroxyacetophenone. Background technique [0002] O-hydroxyacetophenone and p-hydroxyacetophenone are important pharmaceutical and fine chemical intermediates. For example, o-hydroxyacetophenone can be used in the synthesis of class Ia antiarrhythmic drug propafenone hydrochloride, and p-hydroxyacetophenone can be used in paracetamol And the synthesis of ractopamine hydrochloride, etc. [0003] Esterification and Fries rearrangement are classic reactions in organic synthesis. 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 generate o-hydroxyacetophenone and p-hydroxyacetophenone. [0004] The following are several existing methods for preparing p-hydroxyacetophenone and o-hydroxyacetophenone: [0005] (1) Trad...

Claims

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Application Information

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IPC IPC(8): C07C49/825C07C45/54
Inventor 曹日庆王国喜
Owner 曹日庆
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