Method for preparing 4-chloro-3, 5-dimethylphenol

A technology of dimethylphenol and alkyl, which is applied in the field of organic chemical synthesis, can solve the problems of troublesome post-treatment of three wastes, low para-selectivity, heterogeneous reaction, etc., and achieve improved chlorination efficiency and para-selectivity High performance, the effect of improving para-selectivity

Active Publication Date: 2020-08-11
WANHUA CHEM GRP CO LTD
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  • Abstract
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Problems solved by technology

[0003] 4-Chloro-3,5-dimethylphenol is obtained by chlorination of 3,5-dimethylphenol. When chlorine gas is used as the chlorination reagent, the para-substituted product 4-chloro-3,5-dimethylphenol The P / O ratio of (PCMX) to the ortho-substituted product 2-chloro-3,5-dimethylphenol (OCMX) is only 1.5, and the U.S. Patent US4245127 mentions that when sulfuryl chloride is used, the reaction with P / O>6 can be achieved As a result, this method is mostly used in industry at present, but the by-products include sulfur dioxide in addition to hydrogen chloride, which brings troubles to the post-treatment of the three wastes
U.S. Patent No. 4,245,127 also introduces the use of organic sulfides and metal chlorides as co-catalysts. The yield of PCMX is 91.5%, P / O=14.4, and the para-selectivity is not high
[0004] Wu Fei introduced the method of using hydrochloric acid as the chlorination reagent and copper chloride as the catalyst in the article "Study on the Synthesis of 4-Chloro-3,5-Xylenol by Oxidation and Chlorination of 3,5-Dimethylphenol". The selectivity of PCMX can reach 95.47%, and the P / O ratio is 31.40; although this method has certain control over the reaction by-products, it involves a heterogeneous reaction and has a certain influence on the mass transfer of the reaction

Method used

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  • Method for preparing 4-chloro-3, 5-dimethylphenol

Examples

Experimental program
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Effect test

Embodiment 1

[0038] 122.16 g (1.0 mol) of 3,5-dimethylphenol, 3.05 g (2.5 wt% of 3,5-dimethylphenol) of N-methylmorpholine were dissolved in 91.62 g of tetrachloroethylene to give 3, 5-dimethylphenol solution;

[0039] Add 91.62g of tetrachlorethylene solvent into a 1L stainless steel reaction kettle equipped with a mechanical stirrer, a thermometer, and a gas line pipe connected to a tail gas separation and recovery device, replace it with a nitrogen atmosphere, start stirring and heat up to 100°C; 296.76g (3.0 mol) phosgene and 3,5-dimethylphenol solution were slowly and uniformly fed into the reactor within 0.5 h. After the feeding was completed, the reaction was carried out at a constant temperature of 100°C for 2 h, and the reaction was stopped.

[0040] Cool the reaction liquid to room temperature to crystallize and filter out the crystals to obtain 4-chloro-3,5-dimethylphenol.

[0041] According to GC, the conversion rate of 3,5-dimethylphenol in the reaction solution was 97.8%, th...

Embodiment 2

[0043]122.16 g (1.0 mol) of 3,5-dimethylphenol, 2.44 g (2.0 wt% of 3,5-dimethylphenol) of 4-cyclohexylmorpholine were dissolved in 122.16 g of tetrachloroethylene to give 3, 5-dimethylphenol solution;

[0044] Add 122.16g of tetrachlorethylene solvent into a 1L stainless steel reaction kettle equipped with a mechanical stirrer, a thermometer, and a gas line pipe connected to a tail gas separation and recovery device, replace it with a nitrogen atmosphere, start stirring and raise the temperature to 80°C, and 227.52g (2.3 mol) phosgene and 3,5-dimethylphenol solution were slowly and uniformly fed into the reactor within 0.5 h. After the feeding was completed, the reaction was carried out at a constant temperature of 80°C for 2 h, and the reaction was stopped.

[0045] Cool the reaction liquid to room temperature to crystallize and filter out the crystals to obtain 4-chloro-3,5-dimethylphenol.

[0046] According to GC, the conversion rate of 3,5-dimethylphenol in the reaction l...

Embodiment 3

[0048] 122.16g (1.0mol) 3,5-xylenol, 1.22g (1.0wt% of 3,5-xylenol) 4-(2-methoxyethyl)morpholine were dissolved in 152.7g Tetra In vinyl chloride, 3,5-dimethylphenol solution was obtained;

[0049] Add 152.7g of tetrachlorethylene solvent into a 1L stainless steel reaction kettle equipped with a mechanical stirrer, a thermometer, and a gas line pipe connected to a tail gas separation and recovery device, replace it with a nitrogen atmosphere, start stirring and heat up to 85°C, and 197.84g (2.0 mol) phosgene and 3,5-dimethylphenol solution were slowly and uniformly fed into the reactor within 1 hour. After the feeding was completed, react at a constant temperature of 85°C for 3 hours and stop the reaction.

[0050] Cool the reaction liquid to room temperature to crystallize and filter out the crystals to obtain 4-chloro-3,5-dimethylphenol.

[0051] According to GC, the conversion rate of 3,5-dimethylphenol in the reaction liquid was 98.3%, the selectivity of 4-chloro-3,5-dimet...

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Abstract

The invention discloses a method for preparing 4-chloro-3, 5-dimethylphenol. The method comprises the following step: carrying out a chlorination reaction on a 3, 5-dimethylphenol by taking phosgene as a chlorination reagent and a saturated nitrogen-oxygen heterocyclic compound as an accelerant to obtain 4-chloro-3, 5-dimethylphenol. The method has the advantages of no generation of gas sulfide, high para-position selectivity, simplicity and convenience in operation and the like.

Description

technical field [0001] The invention belongs to the field of organic chemical synthesis, and in particular relates to a method for preparing 4-chloro-3,5-dimethylphenol. Background technique [0002] 4-Chloro-3,5-dimethylphenol (p-chloro-m-xylenol, PCMX) is a high-efficiency, broad-spectrum antifungal and antibacterial agent, which is widely used in daily, medical, and industrial sterilization fields. With the prohibition of triclosan and triclocarban, and the improvement of people's quality of life, the demand for sterilization increases, 4-chloro-3,5-dimethylphenol will have greater demand for use. [0003] 4-Chloro-3,5-dimethylphenol is obtained by chlorination of 3,5-dimethylphenol. When chlorine gas is used as the chlorination reagent, the para-substituted product 4-chloro-3,5-dimethylphenol The P / O ratio of (PCMX) to the ortho-substituted product 2-chloro-3,5-dimethylphenol (OCMX) is only 1.5, and the U.S. Patent US4245127 mentions that when sulfuryl chloride is used,...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C37/62C07C37/84C07C39/28
CPCC07C37/62C07C37/84C07C39/28
Inventor 王加琦袁帅丰茂英卢福广曹娜丛鑫刘振峰刘超黄少峰崔乾余炎冰何金同黎源
Owner WANHUA CHEM GRP CO LTD
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