Preparation of 4-hydroxy benzophenone

A technology of hydroxybenzophenone and trihalomethylbenzene, which is applied in the field of preparation of 4-hydroxybenzophenone, can solve problems such as low atom utilization, unsuitability for large-scale commercial preparation, and complicated steps

Inactive Publication Date: 2008-11-05
EAST CHINA UNIV OF SCI & TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The method uses copper oxide as a catalyst to hydrolyze 4-chlorobenzophenone under pressure to obtain 4-hydroxybenzophenone; U.S. Patent US 2,694,729 discloses a method using AlCl 3 As a catalyst, the method for producing hydroxybenzophenone by demethylation of p-methoxybenzophenone, but the steps of these preparation methods are relatively complicated (need to prepare halogenated benzophenone or methoxybenzophenone first) , and the atomic utilization is not high, so it is not suitable for large-scale commercial preparation

Method used

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preparation example Construction

[0019] The method for preparing 4-hydroxybenzophenone according to the present invention includes the following steps:

[0020] Under the condition of 0℃~5℃, the 1,2-dichloroethane solution of catalyst (Lewis acid), trichloromethylbenzene and phenol were added to 1,2-dichloroethane in sequence. Among them, phenol and catalyst The molar ratio of phenol is 1:(1.1-1.5), and the molar ratio of phenol to trichloromethylbenzene is 1:(1.1-1.4). After feeding, react at 20°C~25°C (thin-plate chromatography "tracks" the reaction, and reacts until the raw material point disappears),

[0021] Under stirring conditions, the reaction liquid was poured into ice / water, and solid matter was precipitated. After filtration, the obtained solid matter was recrystallized and dried to become the target (4-hydroxybenzophenone). The filtrate can be distilled to recover the reaction flux (1,2-dichloroethane), which can be recycled.

[0022] By adopting the method for preparing 4-hydroxybenzophenone accordi...

Embodiment 1

[0025] Add 1,2-dichloroethane (80ml) and anhydrous AlCl to a 250ml three-necked flask 3 (20g, 0.15mol), cooled in an ice bath to 0℃-5℃, stirred for half an hour to make anhydrous AlCl 3 Disperse into fine particles, and then add trichloromethylbenzene (15.7ml, 0.11mol) dropwise. The addition is completed within 20 minutes, and then the reaction is incubated for 20 minutes, at which time the reaction solution turns orange-red. Phenol (9.41g, 0.1mol) was dissolved in 1,2-dichloroethane (20ml), the phenol solution was added dropwise at 0°C-5°C, and the drop was completed within 20 minutes. At this time, a large amount of HCl gas is generated, which is absorbed with dilute lye through the gas absorption device. At the later stage of the reaction, when the color of the reaction mixture turns dark purple, the temperature is raised to 20°C-25°C, and the reaction is carried out for 3 hours. After the completion of the reaction, the reaction solution was poured into ice / water with stirring...

Embodiment 2

[0027] Add 1,2-dichloroethane (80ml) and anhydrous AlCl to a 250ml three-necked flask 3 (14.69g, 0.11mol), cooled in an ice bath to 0℃-5℃, stirred for half an hour to make anhydrous AlCl 3 Disperse into fine particles, add trichloromethylbenzene (15.7ml, 0.11mol) dropwise, add it in 20 minutes, keep the reaction for 20 minutes, at this time the reaction solution turns orange-red. Phenol (9.41g, 0.1mol) was dissolved in 1,2-dichloroethane (20ml), the phenol solution was added dropwise at 0°C-5°C, and the drop was completed within 20 minutes. At this time, a large amount of HCl gas is generated, which is absorbed with dilute lye through the gas absorption device. At the later stage of the reaction, when the color of the reaction mixture turns dark purple, the temperature is raised to 20°C-25°C, and the reaction is carried out for 3 hours. After the completion of the reaction, the reaction solution was poured into ice / water with stirring, and allowed to stand at 10°C for 2 hours. The...

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Abstract

The invention relates to a preparation method of 4-hydroxybenzophenone. The preparation method mainly includes the step of: preparing a target compound by using trihalo-methyl benzene to react with phenol by Friedel-Crafts. The product yield by adopting the preparation method of the 4-hydroxybenzophenone of the invention can reach 90 percent; besides, the preparation method of the 4-hydroxybenzophenone also has the advantages of simple steps and low operation cost, etc; the invention is a method which is easy for scale commercial preparation.

Description

Technical field [0001] The invention relates to a preparation method of 4-hydroxybenzophenone. Background technique [0002] 4-Hydroxybenzophenone is a key intermediate for the preparation of (ultraviolet) photoinitiators. [0003] US Patent No. 2,839,541 discloses a method for preparing 4-hydroxybenzophenone by hydrolysis of benzophenone in the presence of a special catalyst. Although the steps of this method are relatively simple, the selectivity of the reaction is not good. In addition to 4-hydroxybenzophenone, there are 2-hydroxybenzophenone and 3-hydroxybenzophenone in the product, and the mixture is Separation and purification is very difficult. [0004] US Patent 1,961,630 discloses a synthetic method for preparing 4-hydroxybenzophenone by hydrolyzing halogenated benzophenone under high temperature and high pressure. The method uses copper oxide as a catalyst to hydrolyze 4-chlorobenzophenone under pressure to obtain 4-hydroxybenzophenone; US patent US 2,694,729 discloses ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C49/83C07C45/43C07C45/00
Inventor 沈永嘉魏玲俞国华王成云
Owner EAST CHINA UNIV OF SCI & TECH
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