Synthesizing process of 2, 5-dichlorophenol

A technology for dichlorophenol and synthesis process, which is applied in the field of synthesis process of 2,5-dichlorophenol, can solve the problems of high industrialized production cost, environmental pollution, equipment corrosion, etc., and achieves reduction of the three-waste disposal amount and production cost. , the effect of short synthetic route

Inactive Publication Date: 2016-08-24
SICHUAN FOURSTAR BIOTECH RANDD CORP
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The process route is simple, but the separation of mixed dichlorophenol is difficult, and the industrial production cost is high; the patent US4326882 proposes to use 2,5-dichloroaniline as raw material, and prepare 2,5-dichloroaniline through diazotization and hydrolysis Phenol, this process is currently relatively mature 2,5-dichlorophenol synthesis process, its biggest disadvantage is serious environmental pollution, and the use of a lar

Method used

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  • Synthesizing process of 2, 5-dichlorophenol

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Example Embodiment

[0034] Example 1

[0035] A synthesis process of 2,5-dichlorophenol, including the following steps:

[0036] A. Halogenation

[0037] Dissolve 1,4-dichlorobenzene in an organic solvent. After adding the catalyst, add bromine at 30°C. After reacting for 10 hours, remove the residual bromine from the system, separate the organic phase, and concentrate and rectify the organic phase to obtain 2,5 -Dichlorobromobenzene; the ratio of bromine to 1,4-dichlorobenzene is 0.5:1, and the conversion rate of 2,5-dichlorobromobenzene is 92.5%;

[0038] B. Hydrolysis

[0039] Dissolve the 2,5-dichlorobromobenzene obtained in step A in an organic solvent, add copper salt catalyst, inorganic alkali and water, and after reacting for 1 hour at a temperature of 150°C and a pressure of 1MPa, the reaction solution is subjected to alkali After washing, acidification, extraction, and desolvation treatment, 2,5-dichlorophenol is obtained; the amount ratio of the inorganic base and the 2,5-dichlorobromobenzene ...

Example Embodiment

[0041] Example 2

[0042] A synthesis process of 2,5-dichlorophenol, including the following steps:

[0043] A. Halogenation

[0044] 1,4-Dichlorobenzene was dissolved in an organic solvent, after adding the catalyst, bromine was added at 50°C, and the remaining bromine was removed after 6 hours of reaction. The organic phase was separated into layers, and the organic phase was concentrated and rectified to obtain 2,5- Dichlorobromobenzene; the ratio of bromine to 1,4-dichlorobenzene is 0.7:1, and the conversion rate of 2,5-dichlorobromobenzene is 95.3%;

[0045] B. Hydrolysis

[0046] Dissolve the 2,5-dichlorobromobenzene obtained in step A in an organic solvent, add a copper salt catalyst, an inorganic base and water, and after reacting for 3 hours at a temperature of 210°C and a pressure of 2MPa, the reaction solution is subjected to alkali After washing, acidification, extraction, and desolventizing treatment, 2,5-dichlorophenol is obtained; the amount ratio of the inorganic base ...

Example Embodiment

[0049] Example 3

[0050] A synthesis process of 2,5-dichlorophenol, including the following steps:

[0051] A. Halogenation

[0052] 1,4-Dichlorobenzene was dissolved in an organic solvent. After adding the catalyst, iodine was added at 40°C. After 9 hours of reaction, the residual iodine was removed. The organic phase was separated into layers. The organic phase was concentrated and rectified to obtain 2,5- Dichloroiodobenzene; the substance ratio of iodine to 1,4-dichlorobenzene is 0.6:1, and the conversion rate of 2,5-dichloroiodobenzene is 93.8%;

[0053] B. Hydrolysis

[0054] Dissolve the 2,5-dichlorobromobenzene obtained in step A in an organic solvent, add a copper salt catalyst and an inorganic base, and after reacting for 3 hours at a temperature of 180°C and a pressure of 1.5MPa, the reaction solution is washed with alkali , Acidification, extraction, and desolventizing treatment to obtain 2,5-dichlorophenol; the amount ratio of the inorganic base to 2,5-dichloroiodobenzen...

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Abstract

The invention discloses synthesizing process of 2, 5-dichlorophenol and belongs to the technical field of fine chemical industry. The synthesizing process includes halogenation and hydrolysis. The synthesizing process has the advantages that bromine or iodine which can be substituted more easily than chlorine is used, the bromine or iodine substituent group is hydrolyzed into hydroxyl after dichlorobenzene is halogenated, and halogenation depth is controlled by controlling the adding amount of the bromine or iodine so as to reduce the content of 2, 5-dichloro-1, 4-dihalogen benzene in the halogenation product; the conversion rate of 2, 5-dichloro halobenzene reaches above 92.0%, and the synthesizing process is short in synthetic route, simple, low in cost, few in produced three wastes and suitable for large-scale production.

Description

technical field [0001] The invention relates to a synthesis process of 2,5-dichlorophenol, which belongs to the technical field of fine chemicals. Background technique [0002] 2,5-Dichlorophenol is an important intermediate of pesticides, medicines, dyes, nitrogen fertilizer synergists and leather antifungal agents. The pure product of 2,5-dichlorophenol is a white needle-like crystal with a special odor, and is currently mostly used in the synthesis of the herbicide 3,6-dichloro-2-methoxybenzoic acid (dicamba). 3,6-dichlorosalicylic acid was synthesized from 2,5-dichlorophenol, followed by O-alkylation to prepare 3,6-dichloro-2-methoxybenzoic acid. 3,6-Dichloro-2-methoxybenzoic acid is a benzoic acid-based herbicide with the trade name of Dicamba, which is mainly used for the control of annual or perennial broad-leaved weeds in grass crop fields such as wheat. With the continuous deepening of research on dicamba-resistant biotechnology and dicamba mixed herbicides, its m...

Claims

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Application Information

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IPC IPC(8): C07C39/30C07C37/02
CPCC07C37/02C07C17/12
Inventor 何路涛李舟卢刚唐昊肖彦玲张华王蕾
Owner SICHUAN FOURSTAR BIOTECH RANDD CORP
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