阅读说明：本技术 一种n-乙烯基咪唑的制备方法 (Preparation method of N-vinyl imidazole ) 是由 吴学敏 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种N-乙烯基咪唑的制备方法,属于乙烯基咪唑制备技术领域,其内容具体包括权1-权9所述方法；本发明N-乙烯基咪唑的制备方法,通过采用原料混合配制,并且仅对原料进行滤液后减压蒸馏的方式提取N-乙烯基咪唑,整个制备方法过程简单、安全可靠,所需使用的制备设备少,原料易得,且价格相对便宜,因而具有很大的创新性和经济,适宜大规模工业化生产和应用。(The invention discloses a preparation method of N-vinyl imidazole, belonging to the technical field of vinyl imidazole preparation, wherein the content specifically comprises the methods of claim 1-claim 9; the preparation method of the N-vinyl imidazole adopts the raw materials to mix and prepare, and extracts the N-vinyl imidazole only by carrying out reduced pressure distillation on the raw materials after filtering, the whole preparation method has simple process, safety and reliability, needs few preparation equipment, is easy to obtain the raw materials, and has relatively low price, thereby having great innovation and economy, and being suitable for large-scale industrial production and application.)

1. A preparation method of N-vinyl imidazole is characterized by comprising the following steps:

s1, sequentially adding 32-38 parts by weight of imidazole, 24-26 parts by weight of potassium hydroxide, 28-34 parts by weight of potassium carbonate and 46-58 parts by weight of deionized water into a reaction kettle, heating while stirring, keeping the pressure in the kettle at 1.3-1.5MPa when the temperature is raised to 60 ℃, and carrying out heat preservation reaction for 1.5-2 hours to obtain a reaction solution;

s2, slowly dripping the reaction solution into a four-neck flask provided with a reflux condenser, a gas absorber, a thermometer and an electric stirrer, stirring while adding, wherein the stirring speed is 120 plus 150rad/min, heating to 55 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 0.5-1h, then continuously heating to 70 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 1-1.5h, stopping heating, and continuously stirring for 0.5 h;

s3, when the temperature of the solution in the four-neck flask is reduced to 40 ℃, adding 12-16 parts by weight of potassium hydroxide into the four-neck flask, heating to 80 ℃ at a speed gradient of 8 ℃/min, keeping the reaction temperature for 2.0h, and stopping heating and stirring;

and S4, after cooling to room temperature, carrying out suction filtration, carrying out reduced pressure distillation on the filtrate for 1.0-1.5h, pouring out the fraction obtained by cooling, heating to 105 ℃ at a speed gradient of 6 ℃/min for reduced pressure distillation, and cooling by a condenser pipe to obtain the fraction which is the light yellow N-vinylimidazole.

2. The method as claimed in claim 1, wherein the stirring speed of the S1 reaction kettle for the reaction solution therein is 260-300 rad/min.

3. The method according to claim 1, wherein 22 to 26 parts by weight of dichloroethane and 8 to 12 parts by weight of absolute ethanol are preliminarily charged in the four-necked flask in S2.

4. The method of claim 1, wherein the heating device of the four-necked flask of S2, S3 and S4 is an electric heating jacket.

5. The method according to claim 1, wherein the potassium hydroxide is added in two equal amounts to the four-necked flask in S3.

6. The method for preparing N-vinylimidazole according to claim 1, wherein the vacuum degree of reduced pressure distillation in the four-necked flask in S4 is 0.05-0.06 MPa.

7. The method for preparing N-vinylimidazole according to claim 1, wherein in step S1, the reaction kettle comprises a kettle body (100) and a stirring mechanism arranged inside the kettle body (100), one side of the top of the kettle body (100) is provided with a feed inlet (150), and the bottom of the kettle body (100) is provided with a discharge outlet (130);

a jacket (160) for heating and insulating the kettle body (100) is arranged at the periphery of the kettle body (100);

the stirring mechanism comprises a stirring shaft (170) arranged at the central position in the kettle body (100) and a stirring blade (140) fixedly arranged on the stirring shaft (170), and the top of the stirring shaft (170) extends upwards to the upper part of the kettle body (100) and is connected with the rotary driving mechanism (120).

8. The method for preparing N-vinylimidazole according to claim 7, wherein heat conducting oil is introduced into the jacket (160), the jacket (160) is provided with an oil inlet (180) for supplying heat conducting oil and an oil outlet (190) for leading out heat conducting oil, and the oil inlet (180) is connected with a heater for heating the heat conducting oil and a refrigerator for cooling the heat conducting oil.

9. The method for preparing N-vinylimidazole according to claim 7 or 8, wherein a temperature sensor (210) for detecting the temperature of the reaction solution in the autoclave body (100), a pressure gauge (220) for detecting the air pressure in the autoclave body (100), and a pressure reducing valve (200) for reducing the pressure of the air in the autoclave body (100) are further installed on one side of the top of the autoclave body (100).

Technical Field

The invention belongs to the technical field of preparation of vinyl imidazole, and particularly relates to a preparation method of N-vinyl imidazole.

Background

N-vinyl imidazole is a very important imidazole derivative, is an important fine chemical raw material, is mainly used for the synthesis of medicines and pesticides and a curing agent of epoxy resin, can also be used for preparing vinyl imidazole ionic liquid, is easy to polymerize into a plastic rubber polymer, is used for a core body of a hardener photosensitive chemical reagent resin inclusion of a resin material, is also used in the petroleum industry and is used as a polymer. With the continuous upgrading of industrial technology in China, the demand of N-vinyl imidazole increases day by day, so that the preparation of N-vinyl imidazole has great economic value and social significance. At present, no mature, safe and reliable specific research report for the preparation method of the N-vinyl imidazole exists at home and abroad.

Disclosure of Invention

The present invention is directed to a method for preparing N-vinylimidazole to solve the problems set forth in the background art.

In order to achieve the purpose, the invention provides the following technical scheme: a process for the preparation of N-vinylimidazole comprising the steps of:

s1, sequentially adding 32-38 parts by weight of imidazole, 24-26 parts by weight of potassium hydroxide, 28-34 parts by weight of potassium carbonate and 46-58 parts by weight of deionized water into a reaction kettle, heating while stirring, keeping the pressure in the kettle at 1.3-1.5MPa when the temperature is raised to 60 ℃, and carrying out heat preservation reaction for 1.5-2 hours to obtain a reaction solution;

s2, slowly dripping the reaction solution into a four-neck flask provided with a reflux condenser, a gas absorber, a thermometer and an electric stirrer, stirring while adding, wherein the stirring speed is 120 plus 150rad/min, heating to 55 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 0.5-1h, then continuously heating to 70 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 1-1.5h, stopping heating, and continuously stirring for 0.5 h;

s3, when the temperature of the solution in the four-neck flask is reduced to 40 ℃, adding 12-16 parts by weight of potassium hydroxide into the four-neck flask, heating to 80 ℃ at a speed gradient of 8 ℃/min, keeping the reaction temperature for 2.0h, and stopping heating and stirring;

and S4, after cooling to room temperature, carrying out suction filtration, carrying out reduced pressure distillation on the filtrate for 1.0-1.5h, pouring out the fraction obtained by cooling, heating to 105 ℃ at a speed gradient of 6 ℃/min for reduced pressure distillation, and cooling by a condenser pipe to obtain the fraction which is the light yellow N-vinylimidazole.

Preferably, the stirring speed of the S1 reaction kettle for the reaction solution therein is 260-300 rad/min.

Preferably, the four-neck flask in the S2 is filled with 22 to 26 parts by weight of dichloroethane and 8 to 12 parts by weight of absolute ethanol in advance.

Preferably, the heating and warming device of the four-neck flask in the S2, S3 and S4 is an electric heating jacket.

Preferably, the potassium hydroxide is added into the four-neck flask in the S3 in two times in the same amount.

Preferably, the vacuum degree of the reduced pressure distillation of the four-neck flask in the S4 is 0.05-0.06 MPa.

Preferably, the reaction kettle in the step S comprises a kettle body and a stirring mechanism arranged in the kettle body, wherein a feeding hole is formed in one side of the top of the kettle body, and a discharging hole is formed in the bottom of the kettle body;

a jacket for heating and insulating the kettle body is arranged at the periphery of the kettle body;

the stirring mechanism comprises a stirring shaft arranged at the central position in the kettle body and a stirring blade fixedly arranged on the stirring shaft, and the top of the stirring shaft upwards extends to the upper part of the kettle body and is connected with a rotary driving mechanism.

Preferably, the heat conduction oil is introduced into the jacket, an oil inlet for supplying the heat conduction oil and an oil outlet for guiding the heat conduction oil are formed in the jacket, and the oil inlet is connected with a heater for heating the heat conduction oil and a refrigerator for cooling the heat conduction oil.

Preferably, one side of the top of the kettle body is further provided with a temperature sensor for detecting the temperature of the reaction solution in the kettle body, a pressure gauge for detecting the air pressure in the kettle body, and a pressure reducing valve for reducing the pressure of the air in the kettle body.

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

the preparation method of the N-vinyl imidazole adopts the raw materials to mix and prepare, and extracts the N-vinyl imidazole only by carrying out reduced pressure distillation on the raw materials after filtering, the whole preparation method has simple process, safety and reliability, needs few preparation equipment, is easy to obtain the raw materials, and has relatively low price, thereby having great innovation and economy, and being suitable for large-scale industrial production and application.

Drawings

FIG. 1 is a flow chart of a process for the preparation of N-vinylimidazole according to the present invention.

FIG. 2 is a structural diagram of a reaction kettle of the preparation method of N-vinylimidazole of the present invention.

In the figure: 100. a kettle body; 120. a rotation driving mechanism; 130. a discharge port; 140. stirring blades; 150. a feed inlet; 160. a jacket; 170. a stirring shaft; 180. an oil inlet; 190. an oil outlet; 200. a pressure reducing valve; 210. a temperature sensor; 220. and a pressure gauge.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

This example is a method for preparing N-vinylimidazole, which includes the following steps:

s1, sequentially adding 32 parts by weight of imidazole, 24 parts by weight of potassium hydroxide, 28 parts by weight of potassium carbonate and 46 parts by weight of deionized water into a reaction kettle, heating while stirring, maintaining the pressure in the kettle at 1.3MPa when the temperature is raised to 60 ℃, and carrying out heat preservation reaction for 1.5 hours to obtain a reaction solution;

s2, slowly dropwise adding the reaction solution into a four-neck flask provided with a reflux condenser, a gas absorber, a thermometer and an electric stirrer, stirring while adding, wherein the stirring speed is 120rad/min, heating to 55 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 0.5h, then continuously heating to 70 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 1h, stopping heating, and continuously stirring for 0.5 h;

s3, when the temperature of the solution in the four-neck flask is reduced to 40 ℃, adding 12 parts by weight of potassium hydroxide into the four-neck flask, heating to 80 ℃ at a speed gradient of 8 ℃/min, keeping the reaction temperature for 2.0h, and stopping heating and stirring;

and S4, after cooling to room temperature, carrying out suction filtration, carrying out reduced pressure distillation on the filtrate for 1.0h, pouring out the fraction obtained by cooling, heating to 105 ℃ at a speed gradient of 6 ℃/min for reduced pressure distillation, and cooling by a condenser pipe to obtain the fraction which is the light yellow N-vinylimidazole.

Preferably, the stirring speed of the S1 reaction kettle for the reaction solution therein is 260 rad/min.

Preferably, the four-neck flask in the S2 is filled with 22 parts by weight of dichloroethane and 8 parts by weight of absolute ethanol in advance.

Preferably, the heating and warming device of the four-neck flask in the S2, S3 and S4 is an electric heating jacket.

Preferably, the potassium hydroxide is added into the four-neck flask in the S3 in two times in the same amount.

Preferably, the vacuum degree of the reduced pressure distillation of the four-neck flask in the S4 is 0.05 MPa.

Example 2

This example is a method for preparing N-vinylimidazole, which includes the following steps:

s1, sequentially adding 38 parts by weight of imidazole, 26 parts by weight of potassium hydroxide, 34 parts by weight of potassium carbonate and 58 parts by weight of deionized water into a reaction kettle, heating while stirring, maintaining the pressure in the kettle at 1.5MPa when the temperature is raised to 60 ℃, and carrying out heat preservation reaction for 2 hours to obtain a reaction solution;

s2, slowly dropwise adding the reaction solution into a four-neck flask provided with a reflux condenser, a gas absorber, a thermometer and an electric stirrer, stirring while adding, wherein the stirring speed is 150rad/min, heating to 55 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 1h, then continuously heating to 70 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 1.5h, stopping heating, and continuously stirring for 0.5 h;

s3, when the temperature of the solution in the four-neck flask is reduced to 40 ℃, adding 16 parts by weight of potassium hydroxide into the four-neck flask, heating to 80 ℃ at a speed gradient of 8 ℃/min, keeping the reaction temperature for 2.0h, and stopping heating and stirring;

and S4, after cooling to room temperature, carrying out suction filtration, carrying out reduced pressure distillation on the filtrate for 1.5h, pouring out the fraction obtained by cooling, heating to 105 ℃ at a speed gradient of 6 ℃/min for reduced pressure distillation, and cooling by a condenser pipe to obtain the fraction which is the light yellow N-vinylimidazole.

Preferably, the stirring speed of the S1 reaction kettle for the reaction solution therein is 300 rad/min.

Preferably, the four-neck flask in the S2 is filled with 26 parts by weight of dichloroethane and 12 parts by weight of absolute ethanol in advance.

Preferably, the heating and warming device of the four-neck flask in the S2, S3 and S4 is an electric heating jacket.

Preferably, the potassium hydroxide is added into the four-neck flask in the S3 in two times in the same amount.

Preferably, the vacuum degree of the reduced pressure distillation of the four-neck flask in the S4 is 0.06 MPa.

Example 3

This example is a method for preparing N-vinylimidazole, which includes the following steps:

s1, sequentially adding 36 parts by weight of imidazole, 25 parts by weight of potassium hydroxide, 32 parts by weight of potassium carbonate and 50 parts by weight of deionized water into a reaction kettle, heating while stirring, maintaining the pressure in the kettle at 1.4MPa when the temperature is raised to 60 ℃, and carrying out heat preservation reaction for 1.8 hours to obtain a reaction solution;

s2, slowly dropwise adding the reaction solution into a four-neck flask provided with a reflux condenser, a gas absorber, a thermometer and an electric stirrer, stirring while adding, wherein the stirring speed is 150rad/min, heating to 55 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 1h, then continuously heating to 70 ℃ at a speed gradient of 5 ℃/min, carrying out heat preservation reaction for 1.5h, stopping heating, and continuously stirring for 0.5 h;

s3, when the temperature of the solution in the four-neck flask is reduced to 40 ℃, adding 16 parts by weight of potassium hydroxide into the four-neck flask, heating to 80 ℃ at a speed gradient of 8 ℃/min, keeping the reaction temperature for 2.0h, and stopping heating and stirring;

and S4, after cooling to room temperature, carrying out suction filtration, carrying out reduced pressure distillation on the filtrate for 1.0-1.5h, pouring out the fraction obtained by cooling, heating to 105 ℃ at a speed gradient of 6 ℃/min for reduced pressure distillation, and cooling by a condenser pipe to obtain the fraction which is the light yellow N-vinylimidazole.

Preferably, the stirring speed of the S1 reaction kettle for the reaction solution therein is 280 rad/min.

Preferably, the four-neck flask in the S2 is filled with 24 parts by weight of dichloroethane and 10 parts by weight of absolute ethanol in advance.

Preferably, the heating and warming device of the four-neck flask in the S2, S3 and S4 is an electric heating jacket.

Preferably, the potassium hydroxide is added into the four-neck flask in the S3 in two times in the same amount.

Preferably, the vacuum degree of the reduced pressure distillation of the four-neck flask in the S4 is 0.06 MPa.

As shown in fig. 2, in order to obtain stable performance of an N-vinylimidazole product, it is necessary to enable the ingredient reaction solution of the present invention to better react in an N-vinylimidazole system during preparation so as to avoid local differences of N-vinylimidazole due to product differences, the present invention provides a reaction kettle, the reaction kettle includes a kettle body 100 and a stirring mechanism arranged inside the kettle body 100, a feeding port 150 is arranged on one side of the top of the kettle body 100, and a discharging port 130 is arranged at the bottom of the kettle body 100;

a jacket 160 for heating and insulating the kettle body 100 is arranged at the periphery of the kettle body 100;

the stirring mechanism comprises a stirring shaft 170 arranged at the central position in the kettle body 100 and a stirring blade 140 fixedly arranged on the stirring shaft 170, wherein the top of the stirring shaft 170 extends upwards to the upper part of the kettle body 100 and is connected with the rotary driving mechanism 120.

The rotation driving mechanism 120 is a motor, and an output shaft of the motor is connected with the stirring shaft 170 through a belt transmission mechanism or a chain transmission mechanism.

The heat conducting oil is introduced into the jacket 160, an oil inlet 180 for supplying the heat conducting oil and an oil outlet 190 for leading out the heat conducting oil are arranged on the jacket 160, and the oil inlet 180 is connected with a heater for heating the heat conducting oil and a refrigerator for cooling the heat conducting oil.

And a temperature sensor 210 for detecting the temperature of the reaction solution in the kettle body 100, a pressure gauge 220 for detecting the air pressure in the kettle body 100, and a pressure reducing valve 200 for reducing the pressure of the air in the kettle body 100 are further installed on one side of the top of the kettle body 100.

In the description of the present invention, it is to be understood that the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above should not be understood to necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

The embodiments of the present invention have been described with reference to the drawings, but the present invention is not limited to the above-mentioned specific embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the spirit and scope of the present invention and the protection scope of the claims.