1. The preparation process of o-aminophenyl ethyl ether is characterized by comprising the following steps:

(1) catalytic hydrogenation: adding a mixture of nitrobenzene, sulfuric acid and ethanol serving as raw materials into a reaction kettle, adding a catalyst and introducing hydrogen, wherein the nitrobenzene in the mixture and the hydrogen and the ethanol undergo a hydrogenation reduction reaction to generate phenylethoxyamine, and performing sulfuric acid transposition to generate o-aminophenylethyl ether sulfate;

(2) solid-liquid separation: carrying out solid-liquid separation on the mixed material in the step (1), enabling the solid mixture to enter the next step, and returning liquid ethanol to the step (1) for reuse;

(3) dissolving: adding water to dissolve the solid obtained in the step (2);

(4) and (3) filtering: filtering the material dissolved in the step (3), separating out the solid catalyst, recycling the solid catalyst to the step (1), and allowing the filtered mother liquor to enter the next step;

(5) acid-base neutralization: introducing ammonia gas to neutralize the mother liquor in the step (4) to be neutral, and separating out o-aminophenyl ethyl ether; refining after oil-water separation to obtain o-aminophenyl ethyl ether;

(6) liquid-solid separation: and (4) concentrating and separating the mother liquor separated in the step (5) to obtain solid sulfate and water, and returning the water to the step (3) for reuse.

2. The process according to claim 1, wherein in the step (1), the catalyst is Pt-C, and the equivalent diameter of the catalyst particles is 0.01-10.0 mm.

3. The process according to claim 1, wherein in the step (1), the reaction temperature is 95-105 ℃ and the hydrogen pressure is 0.3-0.5 MPa.

4. The process for preparing o-aminophenylethyl ether according to claim 1, wherein in the step (1), the molar ratio of the nitrobenzene to the sulfuric acid to the ethanol is 1:1.05 (20-30).

5. The process according to claim 1, wherein in step (1), the reaction kettle is a self-priming reaction kettle.

Background

The o-aminophenyl ethyl ether is an important fine chemical intermediate, and is mainly used for preparing medicines and dyes. Because the product can prevent fat and protein from oxidative deterioration in the storage process, and is often used for preserving feed, food, vitamin A, vitamin E and other medicines, the product has wide application and great domestic and foreign requirements, and therefore, the research and development of the synthesis process of o-aminophenylethyl ether are more and more paid attention to.

The traditional synthetic route of o-aminophenylethyl ether is as follows: the method comprises the steps of taking o-nitrochlorobenzene as a raw material, placing a mixture of the o-nitrochlorobenzene, ethanol and sodium hydroxide in a closed container, preparing o-nitrophenyl ether at high temperature and high pressure, and simultaneously preparing o-nitrophenol sodium, an azo compound and sodium chloride as byproducts. Then catalytic hydrogenation reduction (high temperature and high pressure) is carried out to obtain the o-aminoanisole product. The process comprises the following steps: on one hand, the reaction process is carried out under the conditions of high temperature and high pressure, so that the danger is high; secondly, the raw materials contain organic chlorine, and a certain amount of byproducts are generated in the reaction process, so that the environmental protection problem is difficult to treat.

The process uses o-nitrochlorobenzene and ethanol as raw materials, adopts a phase transfer catalyst, adds sodium hydroxide to generate o-nitrophenyl ether, and then reduces the o-nitrophenyl ether to obtain the o-aminophenyl ether. And is not suitable for the development requirement of green industry.

Disclosure of Invention

The invention aims to solve the defects of the prior art and provides a preparation process of o-aminophenyl ethyl ether, which comprises the following steps:

(1) catalytic hydrogenation: adding a mixture of nitrobenzene, sulfuric acid and ethanol serving as raw materials into a reaction kettle, adding a catalyst and introducing hydrogen, wherein the nitrobenzene in the mixture and the hydrogen and the ethanol undergo a hydrogenation reduction reaction to generate phenylethoxyamine, and performing sulfuric acid transposition to generate o-aminophenylethyl ether sulfate;

(2) solid-liquid separation: carrying out solid-liquid separation on the mixed material in the step (1), enabling the solid mixture to enter the next step, and returning liquid ethanol to the step (1) for reuse;

(3) dissolving: adding water to dissolve the solid obtained in the step (2);

(4) and (3) filtering: filtering the material dissolved in the step (3), separating out the solid catalyst, recycling the solid catalyst to the step (1), and allowing the filtered mother liquor to enter the next step;

(5) acid-base neutralization: introducing ammonia gas to neutralize the mother liquor in the step (4) to be neutral, and separating out o-aminophenyl ethyl ether; refining after oil-water separation to obtain o-aminophenyl ethyl ether;

(6) liquid-solid separation: and (4) concentrating and separating the mother liquor separated in the step (5) to obtain solid sulfate and water, and returning the water to the step (3) for reuse.

Preferably, in step (1), the catalyst is Pt-C, and the equivalent diameter of the catalyst particles is 0.01-10.0 mm.

Preferably, in the step (1), the reaction temperature is 95-105 ℃ and the hydrogen pressure is 0.3-0.5 MPa.

Preferably, in the step (1), the dosage molar ratio of nitrobenzene to sulfuric acid to ethanol is 1:1.05 (20-30).

Preferably, in the step (1), the reaction kettle is a self-suction reaction kettle.

Has the advantages that:

(1) the o-aminophenylethyl ether synthesized by the process is obtained by utilizing nitrobenzene through low-pressure hydrogenation reduction, does not need high temperature and high pressure, and has high safety;

(2) the reaction time is short, about 5 hours are spent from feeding to finishing of the reaction, the productivity is high, the reaction can be completely and directionally converted into a target product by controlling three aspects of hydrogen pressure, the use amount of sulfuric acid and the type selection of a catalyst in the reaction process, a byproduct is basically not contained, the product yield is high, the purity reaches more than 99 percent, the raw material does not contain organic chlorine, the product quality is relatively stable, and all the obtained products reach the drug grade standard;

(3) the ethanol, the catalyst and the water produced in the production process are all used mechanically, and the obtained product is completely marketized without the problem of three-waste discharge.

Drawings

FIG. 1 is a gas chromatogram of nitrobenzene as a starting material;

FIG. 2 is a gas chromatogram of the product o-aminophenylethyl ether.

Detailed Description

For the purpose of enhancing the understanding of the present invention, the present invention will be further described in detail with reference to the following examples and the accompanying drawings, which are only used for explaining the present invention and are not to be construed as limiting the scope of the present invention.

The main process equipment of the invention is as follows: the device comprises a self-suction reaction kettle, a catalyst recovery device, neutralization equipment, a product filtering device, an ammonium sulfate refining device and the like.

Example 1

A preparation process of o-aminophenyl ethyl ether comprises the following steps:

(1) catalytic hydrogenation: adding a mixture of nitrobenzene, sulfuric acid and ethanol serving as raw materials into a reaction kettle, adding a catalyst Pt-C, wherein the equivalent diameter of catalyst particles is 0.01-10.0mm, introducing hydrogen, carrying out hydrogenation reduction reaction on the nitrobenzene and the hydrogen in the mixture and the ethanol to generate phenylethoxyamine, and carrying out sulfuric acid transposition to generate o-aminophenylethyl ether sulfate; the reaction temperature is 95-105 ℃, the hydrogen pressure is 0.3-0.5MPa, and the molar ratio of the dosages of nitrobenzene, sulfuric acid and ethanol is 1:1.05: 26;

(2) solid-liquid separation: carrying out solid-liquid separation on the mixed material in the step (1), enabling the solid mixture to enter the next step, and returning liquid ethanol to the step (1) for reuse;

(3) dissolving: adding water to dissolve the solid obtained in the step (2);

(4) and (3) filtering: filtering the material dissolved in the step (3), separating out the solid catalyst, recycling the solid catalyst to the step (1), and allowing the filtered mother liquor to enter the next step;

(5) acid-base neutralization: introducing ammonia gas to neutralize the mother liquor in the step (4) to be neutral, and separating out o-aminophenyl ethyl ether; refining after oil-water separation to obtain o-aminophenyl ethyl ether;

(6) liquid-solid separation: and (4) concentrating and separating the mother liquor separated in the step (5) to obtain solid sulfate and water, and returning the water to the step (3) for reuse.

The purity of the obtained o-aminophenylethyl ether product is 99.12 percent by gas chromatography detection.

Example 2

A preparation process of o-aminophenyl ethyl ether comprises the following steps:

(1) catalytic hydrogenation: adding a mixture of nitrobenzene, sulfuric acid and ethanol serving as raw materials into a reaction kettle, adding a catalyst Pt-C, wherein the equivalent diameter of catalyst particles is 0.01-10.0mm, introducing hydrogen, carrying out hydrogenation reduction reaction on the nitrobenzene and the hydrogen in the mixture and the ethanol to generate phenylethoxyamine, and carrying out sulfuric acid transposition to generate o-aminophenylethyl ether sulfate; the reaction temperature is 95-105 ℃, the hydrogen pressure is 0.3-0.5MPa, and the molar ratio of the dosages of nitrobenzene, sulfuric acid and ethanol is 1:1.05: 20;

(2) solid-liquid separation: carrying out solid-liquid separation on the mixed material in the step (1), enabling the solid mixture to enter the next step, and returning liquid ethanol to the step (1) for reuse;

(3) dissolving: adding water to dissolve the solid obtained in the step (2);

(4) and (3) filtering: filtering the material dissolved in the step (3), separating out the solid catalyst, recycling the solid catalyst to the step (1), and allowing the filtered mother liquor to enter the next step;

(5) acid-base neutralization: introducing ammonia gas to neutralize the mother liquor in the step (4) to be neutral, and separating out o-aminophenyl ethyl ether; refining after oil-water separation to obtain o-aminophenyl ethyl ether;

(6) liquid-solid separation: and (4) concentrating and separating the mother liquor separated in the step (5) to obtain solid sulfate and water, and returning the water to the step (3) for reuse.

The purity of the obtained o-aminophenylethyl ether product is 99.10 percent by gas chromatography detection.

Example 3

A preparation process of o-aminophenyl ethyl ether comprises the following steps:

(1) catalytic hydrogenation: adding a mixture of nitrobenzene, sulfuric acid and ethanol serving as raw materials into a reaction kettle, adding a catalyst Pt-C, wherein the equivalent diameter of catalyst particles is 0.01-10.0mm, introducing hydrogen, carrying out hydrogenation reduction reaction on the nitrobenzene and the hydrogen in the mixture and the ethanol to generate phenylethoxyamine, and carrying out sulfuric acid transposition to generate o-aminophenylethyl ether sulfate; the reaction temperature is 95-105 ℃, the hydrogen pressure is 0.3-0.5MPa, and the molar ratio of the dosages of nitrobenzene, sulfuric acid and ethanol is 1:1.05: 30;

(2) solid-liquid separation: carrying out solid-liquid separation on the mixed material in the step (1), enabling the solid mixture to enter the next step, and returning liquid ethanol to the step (1) for reuse;

(3) dissolving: adding water to dissolve the solid obtained in the step (2);

(4) and (3) filtering: filtering the material dissolved in the step (3), separating out the solid catalyst, recycling the solid catalyst to the step (1), and allowing the filtered mother liquor to enter the next step;

(5) acid-base neutralization: introducing ammonia gas to neutralize the mother liquor in the step (4) to be neutral, and separating out o-aminophenyl ethyl ether; refining after oil-water separation to obtain o-aminophenyl ethyl ether;

(6) liquid-solid separation: and (4) concentrating and separating the mother liquor separated in the step (5) to obtain solid sulfate and water, and returning the water to the step (3) for reuse.

The purity of the obtained o-aminophenylethyl ether product is 99.22 percent by gas chromatography detection.

Table 1 shows the feed factor for example 1; tables 2 and 3 show the results of analysis of the starting nitrobenzene and the product o-aminophenylethyl ether;

TABLE 1

TABLE 2

TABLE 3

By combining the data in figures 1-2 and tables 1 and 2, the purity of the product o-aminophenylethyl ether reaches over 99 percent, and the product purity is relatively stable, which indicates that the invention provides a reliable new idea for the production of o-aminophenylethyl ether.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.