Preparation method of 5-nitro-2-aminophenol
By hydrolyzing halonitroaniline in an aqueous sodium hydroxide solution, the problems of long synthesis steps, low yield, and excessive waste in the synthesis of 5-nitro-2-aminophenol in the prior art are solved, providing an efficient and low-cost preparation method.
Patent Information
- Application Number
- CN202511063236.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-31
- Publication Date
- 2025-12-19
AI Technical Summary
The existing synthesis process of 5-nitro-2-aminophenol has problems such as long steps, complicated operation, low yield and generation of a large amount of waste, and the raw materials are expensive.
The reaction of halonitroaniline in an aqueous sodium hydroxide solution was carried out by controlling the reaction temperature and pressure and using catalysts such as cuprous bromide, copper oxide, and copper chloride to obtain crude 5-nitro-2-aminophenol, which was then filtered, washed with water, and dried.
This method achieves simple reaction operation, readily available raw materials, high yield, low production cost, and minimal waste, resulting in a 20% reduction in overall production costs.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the chemical technology field of amino phenol compound preparation, and particularly relates to a preparation method of 5-nitro-2-aminophenol. BACKGROUND
[0002] 2-amino-5-nitrophenol (C6H6N2O3) is a light brown needle-like crystal, slightly soluble in water, soluble in ethanol, diethyl ether and concentrated inorganic acid. It is a chemical intermediate, referred to as ANP. It is an important intermediate for the synthesis of dyes, medicines, pesticides and photoelectric materials, and has a wide range of uses. The demand for ANP in the dye and medicine industries is increasing year by year, indicating that the application prospect of ANP is very broad, and it is expected to become an important force to promote the development of the industry. However, at the same time, safety and pollution problems are increasingly worrying.
[0003] According to the literature, the current industrial synthesis process routes mainly include: (1) p-nitroaniline method; (2) o-nitrophenol method; (3) o-aminophenol-urea method; (4) o-aminophenol method. The p-nitroaniline method, the o-nitrophenol method and the o-aminophenol method have the disadvantages of long synthesis steps, complicated operation and low yield, and a large amount of three wastes are generated in the production process which are difficult to treat; although the o-aminophenol-urea method generates less three wastes, a large amount of ammonia gas is generated in the production process. Moreover, the price of the raw material for producing ANP has been high.
[0004] Therefore, a preparation method of 5-nitro-2-aminophenol is urgently needed. SUMMARY
[0005] In order to solve the defects in the prior art, the application provides a preparation method of 5-nitro-2-aminophenol.
[0006] In order to solve the above technical problems, the application provides the following technical scheme: The application provides a preparation method of 5-nitro-2-aminophenol, and the preparation route is as follows:
[0007] The specific steps are as follows: the raw material halogenated nitroaniline and the catalyst are dispersed in a sodium hydroxide aqueous solution, and the reaction is carried out at a reaction temperature of 80-120 DEG C and a pressure of 0.3-1.5 MPa for 12-22 h, the halogenated nitroaniline is hydrolyzed to obtain a crude product 5-nitro-2-aminophenol, and after the reaction is completed, the temperature is cooled to room temperature, and the product is filtered, washed with water and dried to obtain a pure product 5-nitro-2-aminophenol.
[0008] Preferably, the raw material halogenated nitroaniline has the following structure: .
[0009] Preferably, the mass fraction of the aqueous sodium hydroxide solution is 8-16%.
[0010] Preferably, the catalyst is used in an amount of 0.05-0.2% of the molar amount of the raw material halogenated nitroaniline.
[0011] Preferably, the catalyst is cuprous bromide, cupric oxide or cupric chloride.
[0012] Preferably, when X in the structural formula of the raw material halogenated nitroaniline is Cl, the reaction pressure is 0.5-1.0 MPa and the reaction temperature is 80-120 DEG C.
[0013] Preferably, when X in the structural formula of the raw material halogenated nitroaniline is Br, the reaction pressure is 0.3-1.0 MPa and the reaction temperature is 90-120 DEG C.
[0014] Preferably, when X in the structural formula of the raw material halogenated nitroaniline is I, the reaction pressure is 0.5-1.5 MPa and the reaction temperature is 100-120 DEG C.
[0015] Compared with the prior art, the present application has the following beneficial effects: The present application directly hydrolyzes and synthesizes 5-nitro-2-aminophenol from halogenated nitroaniline as a raw material. The preparation method provided by the present application has simple reaction operation, cheap and easily available raw materials, high yield, less three wastes, low production cost and 20% reduction in comprehensive production cost. DETAILED DESCRIPTION
[0016] The preferred embodiments of the present application are described below, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.
[0017] Example 1
[0018] In a 250 mL high-pressure reaction kettle, an aqueous sodium hydroxide solution, a raw material and a catalyst were added, and 0.3 MPa nitrogen was filled; the catalyst was cuprous bromide, the raw material was 2-chloro-4-nitroaniline, the catalyst was used in an amount of 0.05% of the molar amount of the raw material, and the mass fraction of the aqueous sodium hydroxide solution was 8%. After reaction at 80 DEG C for 12 h, the temperature was lowered to room temperature, and the pure product 5-nitro-2-aminophenol was obtained after filtration, water washing and drying.
[0019] Examples 2-11 and Comparative Examples 1-4 The hydrolysis method and reaction conditions of Examples 2-11 and Comparative Examples 1-4 are basically the same as those of Example 1, except for the differences shown in Table 1, wherein A represents the catalyst amount in terms of the percentage of the molar amount of the raw material, and B represents the mass fraction of the aqueous sodium hydroxide solution.
[0020] Table 1: Reaction conditions of halogenated aminophenol.
[0021]
[0022] The reactions of the above examples and comparative examples were detected by chromatography, and the test method was as follows: after the reaction was completed, the reaction solution was cooled to release the pressure, filtered, and detected on-line by liquid chromatography. According to the external standard method, the peak area of the corresponding product was calculated to obtain the yield and purity of the product. The yield and purity of the raw material after the reaction of each example are shown in Table 2.
[0023] Table 2: Detection results.
[0024]
[0025] Finally, it should be noted that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.
Claims
1. A method for preparing 5-nitro-2-aminophenol, characterized in that, The preparation route is shown below: ； The specific steps are as follows: The raw material halonitroaniline and the catalyst are dispersed in an aqueous sodium hydroxide solution and reacted for 12 to 22 h at a reaction temperature of 80 to 120 ℃ and a pressure of 0.3 to 1.5 MPa. The halonitroaniline is hydrolyzed to obtain crude 5-nitro-2-aminophenol. After the reaction is completed, the mixture is cooled to room temperature, filtered, washed with water, and dried to obtain pure 5-nitro-2-aminophenol.
2. The method for preparing 5-nitro-2-aminophenol according to claim 1, characterized in that, The structural formula of the raw material, halonitroaniline, is shown below: 。 3. The method for preparing 5-nitro-2-aminophenol according to claim 1, characterized in that, The sodium hydroxide aqueous solution has a mass fraction of 8-16%.
4. The method for preparing 5-nitro-2-aminophenol according to claim 1, characterized in that, The amount of catalyst used is 0.05 to 0.2% of the molar amount of the raw material halonitroaniline.
5. The method for preparing 5-nitro-2-aminophenol according to claim 1, characterized in that, The catalyst is cuprous bromide, copper oxide, or copper chloride.
6. The method for preparing 5-nitro-2-aminophenol according to claim 1, characterized in that, When X is selected from Cl in the structural formula of the raw material halonitroaniline, the reaction pressure is 0.5 to 1.0 MPa and the reaction temperature is 80 to 120℃.
7. The method for preparing 5-nitro-2-aminophenol according to claim 1, characterized in that, When X is selected from Br in the structural formula of the raw material halonitroaniline, the reaction pressure is 0.3 to 1.0 MPa and the reaction temperature is 90 to 120℃.
8. The method for preparing 5-nitro-2-aminophenol according to claim 1, characterized in that, When X is selected from I in the structural formula of the raw material halonitroaniline, the reaction pressure is 0.5 to 1.5 MPa and the reaction temperature is 100 to 120℃.