CN112300029B - Preparation method of 3-hydroxypropionitrile - Google Patents

Abstract

The invention provides a preparation method of 3-hydroxypropionitrile, which comprises the following steps: reacting acrylonitrile and deionized water in the presence of an alkaline catalyst in a microchannel reactor to obtain a mixed solution containing 3-hydroxypropionitrile. The preparation method of 3-hydroxypropionitrile provided by the invention can be used for continuous production, and has the advantages of simple preparation method, short reaction time and high reaction efficiency; and the final product has high purity and is easy to remove impurities.

Description

Preparation method of 3-hydroxypropionitrile

Technical Field

The invention belongs to the technical field of organic synthesis, and relates to a preparation method of 3-hydroxypropionitrile.

Background

3-hydroxypropionitrile is an important chemical intermediate, and can be used for preparing 3-aminopropanol, and the 3-aminopropanol is a main raw material for preparing vitamin B5 (panthenol). Panthenol is a valuable additive in cosmetics, and can be used for synthesizing medicine for treating cardiovascular diseases such as propranolol and neocodeine, and preparing antitumor medicine cyclophosphamide.

The prior art currently has several methods for preparing 3-hydroxypropionitrile: (1) the reaction of chloroethanol with cyanide, and the reaction of 2-chloroethanol with cyanide can produce 3-hydroxypropionitrile, but in this method, 2-chloroethanol is expensive, the reaction exotherm is difficult to control, more solid waste is produced, and cyanide is too dangerous; (2) the method comprises the following steps of (1) reacting ethylene oxide with hydrocyanic acid, wherein a plurality of patents relate to one-step preparation of 3-hydroxypropionitrile by using the reaction of ethylene oxide and hydrocyanic acid, although the atom economy is high, the ethylene oxide used in the method is difficult to treat, and the hydrocyanic acid has high toxicity, so that the large-scale application of the hydrocyanic acid is limited; (3) the acrylonitrile hydration method is characterized in that under the alkali catalysis, acrylonitrile and water are subjected to addition reaction in a ratio of 1:1 to prepare 3-hydroxypropionitrile, but under the alkali condition, the generated 3-hydroxypropionitrile is easy to further react with another molecule of acrylonitrile to generate a mixture with more bis (cyanoethyl) ether, and the mixture needs to be catalyzed and pyrolyzed by using an alkali catalyst to generate more 3-hydroxypropionitrile, so that the process is too complex.

Therefore, it is desirable to provide a method for producing 3-hydroxypropionitrile, which is simple in process and high in yield.

Disclosure of Invention

The invention aims to provide a preparation method of 3-hydroxypropionitrile, which can be used for continuous production, and has the advantages of simple preparation method, short reaction time and high reaction efficiency; and the final product has high purity and is easy to remove impurities.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a process for the preparation of 3-hydroxypropionitrile, comprising: reacting acrylonitrile and deionized water in the presence of an alkaline catalyst in a microchannel reactor to obtain a mixed solution containing 3-hydroxypropionitrile.

The preparation method provided by the invention can realize continuous production, and has the advantages of short reaction time and high reaction efficiency.

In order to ensure the reaction efficiency of the method is high and not to cause waste of raw materials, the mass ratio of the acrylonitrile to the deionized water is 1 (0.2-6), such as 1:1, 1:2, 1:3, 1:4, 1:5 and the like.

In a preferred embodiment of the present invention, the basic catalyst is selected from tertiary trialkyl amines, and the alkyl group is a C1-C5 alkyl group, such as a methyl, ethyl, propyl, n-butyl, isobutyl, pentyl, or other linear or branched alkyl group having 1-5 carbon atoms.

As a preferred technical scheme of the invention, the alkaline catalyst is selected from trimethylamine, the boiling point of the trimethylamine is low, the trimethylamine can be removed at a low treatment temperature in the subsequent treatment process, the impurity removal is simple, and the trimethylamine is selected as the catalyst, so that the purity of the product can be improved.

In a preferred embodiment of the present invention, the mass ratio of the trialkyl tertiary amine to acrylonitrile is (0.005-0.05):1, for example, 0.008:1, 0.01:1, 0.02:1, 0.03:1, 0.04:1, and preferably 0.03: 1.

In order to make the reaction more complete and ensure that the content of impurities is lower, the reaction time of the invention is 5-25min, such as 7min, 8min, 10min, 12min, 15min, 18min, 20min, 22min and the like, preferably 10-15min, such as 11min, 12min, 13min, 14min and the like.

If the reaction time is too long, more impurities are caused, the post-treatment is difficult, and the purity of the product is reduced; if the reaction time is too short, the reaction of the raw materials cannot be ensured completely, resulting in waste of raw materials.

As a preferred technical scheme of the invention, the temperature of the microchannel reactor is 140-.

In a preferred embodiment of the present invention, the microchannel reactor has a reaction gauge pressure of 0.5 to 3.0MPa, for example, 1.0MPa, 1.5MPa, 2.0MPa, 2.1MPa, 2.2MPa, 2.3MPa, 2.4MPa, 2.5MPa, 2.8MPa, etc., preferably 2.0 to 2.5 MPa.

In a preferred embodiment of the present invention, the mixed liquid containing 3-hydroxypropionitrile is rectified to obtain the 3-hydroxypropionitrile.

The preparation method provided by the invention can obtain the 3-hydroxypropionitrile with the purity of more than 98% by simple rectification, and has simple and convenient post-treatment process and lower cost.

As a preferred embodiment of the present invention, the preparation method comprises:

(1) uniformly mixing acrylonitrile, deionized water and an alkaline catalyst in a premixer of a microchannel reactor, and then entering a constant-temperature reactor of the microchannel reactor for reaction to obtain a mixed solution containing 3-hydroxypropionitrile;

(2) and rectifying the mixed liquid containing the 3-hydroxypropionitrile to obtain the 3-hydroxypropionitrile.

Compared with the prior art, the invention has the following beneficial effects:

(1) the preparation method provided by the invention can complete the reaction within 25min in a short reaction time, thereby remarkably improving the reaction efficiency;

(2) the preparation method provided by the invention has the advantages of higher reaction conversion rate and higher economical efficiency; meanwhile, the alkaline catalyst adopted by the invention is easy to remove in the rectification process, so that the final product has higher purity;

(3) the 3-aminopropionitrile prepared by the preparation method provided by the invention has high yield of more than 94.5 percent and high purity of more than 97.5 percent.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The preparation method of the 3-aminopropionitrile comprises the following steps:

(1) simultaneously pumping acrylonitrile, trimethylamine and water into a premixer of a microchannel reactor by using flow rates, wherein the reaction gauge pressure is 2.0MPa, the flow rate of the acrylonitrile is controlled to be 60mL/h, the flow rate of the trimethylamine is controlled to be 1.8mL/h, and the flow rate of the water is controlled to be 300.0 mL/h; allowing the mixed reaction solution to enter a constant temperature reactor of the microchannel reactor for reaction at 160 ℃, wherein the retention time of the reaction solution is 15min, and obtaining a mixed solution containing 3-hydroxypropionitrile;

(2) and cooling the mixed solution by a cooling coil, and rectifying to obtain a final product.

Examples 2 to 4

The difference from example 1 is that in this example, the reaction solution residence time was 10min (example 2), 5min (example 3) and 25min (example 4).

Example 5

The preparation method of the 3-aminopropionitrile comprises the following steps:

(1) simultaneously pumping acrylonitrile, trimethylamine and water into a premixer of a microchannel reactor by using flow rates, wherein the reaction gauge pressure is 2.5MPa, the flow rate of the acrylonitrile is controlled to be 60mL/h, the flow rate of the trimethylamine is controlled to be 1.8mL/h, and the flow rate of the water is controlled to be 360.0 mL/h; allowing the mixed reaction solution to enter a constant temperature reactor of the microchannel reactor for reaction at 165 ℃ for 10min to obtain a mixed solution containing 3-hydroxypropionitrile;

(2) and cooling the mixed solution by a cooling coil, and rectifying to obtain a final product.

Example 6

The preparation method of the 3-aminopropionitrile comprises the following steps:

(1) simultaneously pumping acrylonitrile, trimethylamine and water into a premixer of a microchannel reactor by using flow rates, wherein the reaction gauge pressure is 2.8MPa, the flow rate of the acrylonitrile is controlled to be 60mL/h, the flow rate of the trimethylamine is controlled to be 1.8mL/h, and the flow rate of the water is controlled to be 350.0 mL/h; allowing the mixed reaction solution to enter a constant temperature reactor of the microchannel reactor for reaction at 176 ℃, wherein the retention time of the reaction solution is 10min, and obtaining a mixed solution containing 3-hydroxypropionitrile;

(2) and cooling the mixed solution by a cooling coil, and rectifying to obtain a final product.

Example 7

The difference from example 1 is that in this example, the basic catalyst is sodium carbonate.

Comparative example 1

The preparation method of the 3-aminopropionitrile comprises the following steps:

(1) sequentially placing 480g (9mo1) of acrylonitrile, 4.5g (45mmol,0.5 mol%) of trimethylamine and 324g (18mol) of water in an autoclave, replacing nitrogen for three times, heating to 120 ℃ within 60min under stirring at the rotating speed of 300rpm, observing the highest pressure in the autoclave to be 0.50MPa, sampling a GC in the reaction process to monitor the reaction process, keeping the temperature for about 120min, stopping heat preservation, cooling the system to 10 +/-5 ℃, and finishing the reaction;

(2) the kettle is disassembled, the materials are transferred to a 1000mL separating funnel, the water phase is separated out, 50g of water is added into the organic phase, liquid separation is carried out again after shaking up, 558g of organic phase is obtained, and the organic phase is rectified to obtain the final product.

Performance testing

The final products provided in examples 1-7 and comparative example 1 were weighed and tested for purity and yield of 3-aminopropionitrile, as shown in Table 1:

TABLE 1

Sample (I)	Yield of	Purity of
			Example 1	95.3	98.1
Example 2	95.1	98.3
			Example 3	94.5	98.1
Example 4	95.9	98.6
			Example 5	96.5	98.8
Example 6	94.6	97.8
			Example 7	82.6	86.5
Comparative example 1	74.1	93.0

The embodiment and the performance test show that the preparation method provided by the invention is simple and feasible, and the 3-aminopropionitrile prepared by the method has high yield and high purity.

As can be seen from the comparison between example 1 and examples 2-4, the reaction time defined by the preparation method provided by the invention is within the range defined by the invention, preferably 10-15min, and the obtained 3-aminopropionitrile has higher yield and purity; as is clear from the comparison between example 1 and example 7, in the present invention, a tertiary trialkylamine is preferably used as a basic catalyst, which facilitates removal of impurities and can provide a product with high purity. As can be seen from the comparison between example 1 and comparative example 1, the preparation method provided by the invention has the advantages of extremely short reaction time, high yield and high purity.

The applicant states that the present invention is illustrated by the above examples to the preparation of 3-hydroxypropionitrile according to the present invention, but the present invention is not limited to the above detailed processes, i.e. it is not meant to imply that the present invention must rely on the above detailed processes to be practiced. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims (11)

1. A method for preparing 3-hydroxypropionitrile, comprising: reacting acrylonitrile and deionized water in a microchannel reactor in the presence of an alkaline catalyst to obtain a mixed solution containing 3-hydroxypropionitrile;

the temperature of the microchannel reactor is 150-180 ℃, the reaction gauge pressure of the microchannel reactor is 2.0-3.0MPa, and the reaction time is 5-25 min.

2. The preparation method according to claim 1, wherein the mass ratio of the acrylonitrile to the deionized water is 1 (0.2-6).

3. The method according to claim 1, wherein the basic catalyst is selected from the group consisting of tertiary trialkylamines, and the alkyl group is a C1-C5 alkyl group.

4. The method according to claim 3, wherein the basic catalyst is trimethylamine.

5. The production method according to claim 3, wherein the mass ratio of the trialkyl tertiary amine to acrylonitrile is (0.005-0.05): 1.

6. The production method according to claim 5, wherein the mass ratio of the trialkyl tertiary amine to acrylonitrile is 0.03: 1.

7. The method according to claim 1, wherein the reaction time is 10 to 15 min.

8. The method as claimed in claim 1, wherein the temperature of the microchannel reactor is 150-160 ℃.

9. The process of claim 1 wherein the microchannel reactor has a reaction gauge pressure of from 2.0 to 2.5 MPa.

10. The method according to claim 1, wherein the 3-hydroxypropionitrile is obtained by rectifying the mixed solution containing 3-hydroxypropionitrile.

11. The production method according to any one of claims 1 to 10, characterized by comprising:

(1) uniformly mixing acrylonitrile, deionized water and an alkaline catalyst in a premixer of a microchannel reactor, and then entering a constant-temperature reactor of the microchannel reactor for reaction to obtain a mixed solution containing 3-hydroxypropionitrile;

(2) and rectifying the mixed liquid containing the 3-hydroxypropionitrile to obtain the 3-hydroxypropionitrile.