Safe production device for synthesizing 2-chloro-3-pyridylamine by using high-purity chlorine

Abstract

The utility model relates to the technical field of organic synthesis, and discloses a safe production device for synthesizing 2-chloro-3-pyridylamine by using high-purity chlorine, which comprises a liquid chlorine gasification device, a chlorine condenser, a chlorination reactor and a reaction post-treatment continuous extraction device, the reaction post-treatment continuous extraction device comprises mutually connected centrifugal extractors, a chlorine pipeline between the liquid chlorine gasification device and the reaction post-treatment continuous extraction device is provided with a vertically connected part, the vertically connected part of the chlorine pipeline is provided with a chlorine condenser, and the chlorine introduction pipe comprises a main pipe and an annular pipe; dispersed air holes are evenly distributed in the annular pipe, and the centrifugal extractor is connected with the bottom of the chlorination reactor. Chlorine is uniformly released through the annular pipe and fully reacts with materials; the vertical condenser can effectively prevent nitrogen trichloride impurities in chlorine from gathering to increase safety risks, the continuous extraction device is ingeniously arranged, reaction by-product residues are effectively removed, and the wastewater output is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of organic synthesis technology, specifically a safe production device of 2-chloro-3-pyridine amine using high-purity chlorine gas to participate in synthesis. BACKGROUND

[0002] 2-chloro-3-pyridine amine is an important chemical intermediate raw material in the fields of medicine, food additive and pesticide, etc. such as haloperidol, delavirdine and chlorantraniliprole, and is widely used. It has important practical significance to produce 2-chloro-3-pyridine amine safely, efficiently and with high quality by using advanced production technology. It is prepared by chlorination reaction requiring chlorine gas. The chlorine gas generally has two sources: one is to use high-purity chlorine gas directly, and the other is to use "one-pot method" to produce chlorine gas. Due to the problems in the equipment technology of liquid chlorine gasification and high-purity gaseous chlorine, existing factories basically avoid the use of high-purity chlorine gas, and choose the latter, that is, hydrogen peroxide and hydrochloric acid are directly reacted in the chlorination reactor to produce chlorine gas, and the produced chlorine gas is directly reacted with the starting material 3-aminopyridine in the chlorination reactor. However, during the reaction, the reaction of chlorine gas in the chlorination reactor is not sufficient, resulting in waste of chlorine gas. However, the "one-pot method" reaction has many types of substrates, and the purity of the produced chlorine gas is not high, the chlorination reaction is not sufficient, the product quality and yield are greatly discounted, the related impurity treatment is difficult, and the use of hydrogen peroxide will also lead to large amount of waste water and environmental protection treatment.

[0003] Most of the existing production of 2-chloro-3-pyridine amine adopts an intermittent reaction production process device, involves frequent material turnover and use of many devices including turnover containers, and poses a great challenge to site and energy consumption demand. The corresponding safety and environmental protection risk is also great. Some manufacturers have tried to apply micro-channel reaction and continuous treatment device. CN116854633A and CN218689513U are both about continuous synthesis reaction device for "one-pot method" synthesis of 2-chloro-3-aminopyridine, including first reaction module (or first reaction zone) and second reaction module (or second reaction zone), which uses micro-channel reactor to avoid reaction heat accumulation and reduce safety risk in theory and relatively small scale production. However, in reality, there is still a bottleneck contradiction between large-scale production capacity and large amount of reaction heat safety risk and micro-channel reaction amount. Moreover, the process used by these continuous production devices still cannot overcome the above-mentioned shortcomings of "one-pot method" synthesis of 2-chloro-3-pyridine amine.

[0004] Therefore, a new technical solution is needed to solve the above technical problems. SUMMARY

[0005] In order to solve the above problems, the utility model discloses a kind of safe production device using high-purity chlorine gas to participate in synthesis 2-chloro-3-pyridylamine, by adding annular pipe in chlorination reactor, by the gas hole of evenly distributed on annular pipe release chlorine and the material in chlorination reactor fully react, chlorine pipeline between liquid chlorine gasification device and chlorination reactor is equipped with the part of vertical connection, which can effectively avoid liquefaction of chlorine, i.e. avoid nitrogen trichloride impurity in chlorine aggregation and increase safety risk, continuous extraction device is ingeniously arranged, effectively remove reaction byproduct ADCP (2,6-dichloro-3-pyridylamine) and 3-AP (3-aminopyridine) residue, also reduce the waste water output.

[0006] The technical scheme of the utility model is: a safe production device using high-purity chlorine gas to participate in synthesis 2-chloro-3-pyridylamine, comprising liquid chlorine gasification device, chlorine condenser, chlorination reactor and post-reaction continuous extraction device, the chlorination reactor is provided with chlorine inlet pipe, the post-reaction continuous extraction device comprises three centrifugal extractors connected with each other, the chlorine pipeline between the liquid chlorine gasification device and the post-reaction continuous extraction device is provided with a vertically connected part, the vertically connected part of the chlorine pipeline is provided with a chlorine condenser, the chlorine inlet pipe comprises a main pipe and an annular pipe, the annular pipe is uniformly distributed with dispersed air holes, and the centrifugal extractor is connected with the bottom of the chlorination reactor.

[0007] Preferably, the device temperature of the liquid chlorine gasification device is maintained above 85 DEG C, the chlorine pipeline of the liquid chlorine gasification device is connected with the main pipe of the chlorine inlet pipe, and the chlorine pipeline passes through the condensing pipeline in the chlorine condenser.

[0008] By adopting the above technical scheme, the temperature is always controlled above 85 DEG C, and the liquid chlorine can be completely gasified to avoid residual nitrogen trichloride, so as to reduce the safety risk and improve the safety.

[0009] Preferably, the condensing pipeline in the chlorine condenser surrounds the chlorine pipeline, and the chlorine condenser is vertically placed along with the chlorine pipeline.

[0010] By adopting the above technical scheme, the condensing pipeline follows the vertical direction of the chlorine pipeline, so that the internal material directly falls from the chlorine pipeline due to the action of gravity, and the cooled nitrogen trichloride is prevented from being accumulated in the tank, thereby reducing the safety risk.

[0011] Preferably, the annular pipe is located in the chlorination reactor, and the annular pipe is sleeved outside the stirring paddle of the chlorination reactor, and the stirring diameter of the stirring paddle is smaller than the inner diameter of the annular pipe, i.e. the annular pipe is outside the movement range of the stirring paddle.

[0012] By adopting the above technical scheme, the stirring paddle does not contact the annular pipe when working, so that the stirring paddle does not hit the annular pipe, thereby preventing the annular pipe from being broken.

[0013] Preferably, the annular pipes are sequentially arranged on the main pipe until the bottom of the main pipe, the annular pipes and the main pipe are communicated, the annular pipes are parallel to each other, the air holes on the annular pipes are uniformly distributed on the annular pipes and penetrate the annular pipes.

[0014] By adopting the above technical scheme, the annular pipes are arranged in parallel, so that the chlorine gas in the annular pipes can be uniformly released when the chlorine gas is released in the chlorination reactor. The air holes on the annular pipes are micropores with a pore size of ≤2 μm, so that the reaction substrate or product particles cannot enter the pipes to cause blockage. The part of the annular pipes where the air holes are distributed can be provided with a filter screen or other devices with a gas filtering function to avoid material blockage of the pipes. The air holes on the annular pipes are uniformly distributed, the chlorine gas in the annular pipes is uniformly released to the surroundings of the stirring paddle through the air holes, the stirring paddle uniformly disperses the reaction materials and the chlorine gas, which is beneficial to the uniform dispersion of the reaction materials and the chlorine gas, rapid and sufficient reaction, smooth diffusion and transmission of reaction heat, reduction of safety risks, avoidance of too much concentration of the reaction to cause too many side reactions, reduction of the generation of ADCP impurities and the purification difficulty of the impurities, and improvement of the yield and product quality.

[0015] Preferably, the annular pipes and the main pipe are tangent to each other, the position where the annular pipes and the main pipe are tangent to each other is communicated with the main pipe, and the annular pipe at the end of the main pipe is tangent to and communicated with the end of the main pipe.

[0016] By adopting the above technical scheme, the chlorine gas in the main pipe is transported to the annular pipe through the position where the annular pipe is tangent to the main pipe, and the chlorine gas is released from the air holes of the annular pipe.

[0017] Preferably, the post-reaction treatment continuous extraction device comprises a centrifugal extractor a, a centrifugal extractor b and a centrifugal extractor c, the bottom of the chlorination reactor is connected to the top of the centrifugal extractor a, the light phase of the centrifugal extractor a is connected to the top of the centrifugal extractor b, the heavy phase of the centrifugal extractor b is connected to the top of the centrifugal extractor c, and the heavy phase of the centrifugal extractor c is connected to the top of the centrifugal extractor a.

[0018] By adopting the above technical scheme, the three continuous post-reaction treatment continuous extraction devices continuously perform post-treatment of the reaction liquid to remove the main impurity ADCP (2,6-dichloro-3-pyridine amine) and a small amount of 3-AP impurity (residual starting material 3-pyridine amine) in the reaction liquid. The continuous extraction reduces the amount of wastewater in the subsequent reaction step, and the liquid material is continuously back-extracted to remove the residual amount of 3-AP impurity without increasing the labor and material costs, so as to avoid affecting the yield and impurity treatment in the subsequent reaction step. The heavy phase material produced by the extraction is exactly what is needed for the extraction of the centrifugal extractor a, and is recycled and used, so that the product quality is improved without generating additional waste.

[0019] The utility model discloses an advantage: 1, the utility model discloses a chlorine gas inlet pipe is equipped with annular pipe in chlorination reactor, and the annular pipe on the gas hole can evenly release the chlorine gas in the pipe, and the annular pipe is located at the periphery of the stirring paddle, and the chlorine gas is reacted evenly with the mixture in the chlorination reactor, is favorable to the reaction fast and sufficient, also is favorable to the reaction heat smooth diffusion and transmission, reduces the security risk, also avoids too much byproduct reaction from happening due to the too concentrated reaction, thereby reduces the impurity of adcp generation and the impurity purification difficulty, improves the yield and product quality.

[0020] 2, the utility model discloses the chlorine gas pipeline between liquid chlorine gasification and chlorination reactor has vertical setting portion, and installs vertical condenser at vertical pipeline position, like this can effectively prevent the nitrogen trichloride substance that is condensed from remaining aggregation in the tank, reduces the security risk.

[0021] 3, the utility model discloses the three continuous reaction post -treatment continuous extraction device, can continuously carry out the post -treatment of reaction liquid, and the material is recycled, and the product quality is improved under the condition of not generating additional waste.

[0022] 4, the utility model discloses the direct use of high -purity chlorine gas participates in the reaction, and the related impurity of hydrogen peroxide and hydrochloric acid reaction is less, and the large amount of wastewater produced by hydrogen peroxide use and treatment is less, and the extraction and back extraction process technology is applied ingeniously, and then the improved liquid chlorine gasification device, the improved reaction " chlorine " device and the continuous extraction / back extraction device after reaction are combined, and the production efficiency is greatly improved, and the challenge of traditional production device technology to manpower and material turnover is avoided. ACCURACY

[0023] Figure 1 It is the structural schematic diagram of the utility model;

[0024] Figure 2 It is the structural schematic diagram of the chlorine gas pipeline of the utility model;

[0025] Figure 3 It is the structural schematic diagram of the gas hole of the utility model Figure 2 .

[0026] Figure 4 It is the structural schematic diagram of the annular pipe of the utility model three.

[0027] Among them: 1, liquid chlorine gasification device, 2, chlorine gas condenser, 3, chlorine gas pipeline, 4, chlorine gas inlet pipe, 401, main pipe, 402, annular pipe, 4021, gas hole, 5, chlorine gas condenser, 6, chlorination reactor, 601, stirring paddle, 7, centrifugal extractor a, 8, centrifugal extractor b, 9, centrifugal extractor c. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the utility model will be clearly and completely described in connection with the drawings in the embodiments of the utility model.

[0029] As shown in the figure, Figures 1-4 The safety production device for synthesizing 2-chloro-3-pyridine amine by using high-purity chlorine includes a liquid chlorine gasification device 1, a chlorine condenser 2, a chlorination reactor 6, and a post-reaction continuous extraction device, the chlorination reactor 6 is internally provided with a chlorine inlet pipe 4, the post-reaction continuous extraction device includes three centrifugal extractors connected with each other, the chlorine pipeline 3 between the liquid chlorine gasification device 1 and the post-reaction continuous extraction device is provided with a vertically connected part, the chlorine pipeline 3 is provided with the chlorine condenser 2, the chlorine inlet pipe 4 includes a main pipe 401 and an annular pipe 402, the annular pipe 402 is uniformly distributed with dispersed air holes 4021, and the centrifugal extractor is connected with the bottom of the chlorination reactor 6.

[0030] The device temperature of the liquid chlorine gasification device 1 is kept above 85 DEG C, the chlorine pipeline 3 of the liquid chlorine gasification device 1 is connected with the main pipe 401 of the chlorine inlet pipe, the chlorine pipeline 3 passes through the condensing pipeline in the chlorine condenser 2, the temperature is always controlled above 85 DEG C, liquid chlorine can be completely gasified, so as to avoid residual nitrogen trichloride and cause safety risks, and safety is improved.

[0031] The condensing pipeline in the chlorine condenser 2 surrounds the chlorine pipeline 3, the chlorine condenser 2 is also vertically placed along the vertical direction of the chlorine pipeline 3, the condensing pipeline follows the vertical direction of the chlorine pipeline 3, the condensing area between the condensing pipeline and the chlorine pipeline 3 can be increased, the chlorine temperature in the chlorine pipeline 3 is reduced, safety risks are reduced, and the chlorine pipeline 3 is vertically placed, so that the internal materials directly fall from the chlorine pipeline due to the action of gravity, the cooled nitrogen trichloride is avoided to be accumulated in the tank, and safety risks are reduced.

[0032] The annular pipe 402 is located in the chlorination reactor 6, the annular pipe 402 is sleeved outside the stirring paddle 601 of the chlorination reactor 6, the stirring diameter of the stirring paddle 601 is smaller than the inner diameter of the annular pipe 402, that is, the annular pipe 402 is outside the movement range of the stirring paddle 601, the annular pipe 402 does not contact the stirring paddle 601 when the stirring paddle 601 works, so that the stirring paddle 601 will not hit the annular pipe 402, and the annular pipe 402 is prevented from being broken.

[0033] The annular pipes 402 are sequentially arranged on the main pipe 401 until the bottom of the main pipe 401, the number of the annular pipes 402 is more than one, the annular pipes 402 are in communication with the main pipe 401, the annular pipes 402 are parallel to each other, the air holes 4021 on the annular pipes 402 are dispersed on the annular pipes 402 and penetrate the annular pipes 402, and the annular pipes 402 are arranged in parallel. When the chlorination reactor 6 is released, the chlorine gas in the annular pipes 402 can be uniformly released. The air holes 4021 on the annular pipes 402 are micropores with a pore size of ≤2 μm, so that the reaction substrate or product particles cannot enter the pipe to cause blockage. The part of the annular pipes 402 where the air holes 4021 are distributed can be provided with a filter screen or other gas filtering device to avoid material blockage. The air holes 4021 on the annular pipes 402 are uniformly dispersed, the chlorine gas in the annular pipes 402 is uniformly released to the surroundings of the stirring paddle 601, the stirring paddle 601 uniformly disperses the reaction materials and chlorine gas, which is beneficial to the uniform dispersion of the reaction materials and chlorine gas, rapid and sufficient reaction, smooth diffusion and transmission of reaction heat, reduction of safety risk, avoidance of too much side reaction caused by too concentrated reaction, reduction of ADCP impurities and impurity purification difficulty, and improvement of yield and product quality.

[0034] The annular pipes 402 are tangent to the main pipe 401, the tangent position of the annular pipes 402 and the main pipe 401 is in communication with the main pipe 401, the annular pipe 402 at the end of the main pipe 401 is tangent to and in communication with the end of the main pipe 401, and the chlorine gas in the main pipe 401 is transported to the annular pipe 402 through the tangent position of the annular pipe 402, so that the annular pipe 402 releases chlorine gas from the air holes.

[0035] The post-treatment continuous extraction device includes a centrifugal extractor a7, a centrifugal extractor b8 and a centrifugal extractor c9. The bottom of the chlorination reactor 6 is connected to the top of the centrifugal extractor a7, the light phase of the centrifugal extractor a7 is connected to the top of the centrifugal extractor b8, the heavy phase of the centrifugal extractor b8 is connected to the top of the centrifugal extractor c9, and the heavy phase of the centrifugal extractor c9 is connected to the top of the centrifugal extractor a7. The three continuous post-treatment continuous extraction devices continuously treat the reaction liquid to remove the main impurity ADCP (2,6-dichloro-3-pyridine amine) and a small amount of 3-AP impurity (residual starting material 3-pyridine amine) in the reaction. The continuous extraction reduces the amount of wastewater in the subsequent reaction step. The liquid material is continuously stripped, and the residual amount of 3-AP impurity is removed again without increasing labor and material costs, so as to avoid affecting the yield and impurity treatment of the subsequent reaction step. The heavy phase material produced by extraction is exactly what is needed for extraction of the centrifugal extractor a, which is recycled and used, improves the product quality without generating additional waste.

[0036] Liquid chlorine is gasified in the liquid chlorine gasification device 1, and chlorine gas is generated and enters the chlorine gas inlet pipe 4 through the vertical chlorine gas pipe 3 and the chlorine gas condenser 2. The chlorine gas in the chlorine gas inlet pipe is transported to the annular pipe 402 through the main pipe 401, and then released from the air holes 4021 of the annular pipe 402 to uniformly disperse and react with the reactant in the chlorination reactor 6. The reaction liquid after the reaction is extracted by the centrifugal extractor a7 of the post-treatment continuous extraction device, the light phase material of the centrifugal extractor a7 is extracted in the centrifugal extractor b8, the waste water after acid-base neutralization is removed, the amount of waste water in the subsequent reaction step is greatly reduced, the heavy phase material in the centrifugal extractor b8 is transported to the centrifugal extractor c9 for continuous back extraction, and the residual amount of 3-DCP impurities is removed again to avoid affecting the yield and impurity treatment of the subsequent reaction step. The heavy phase material produced by extraction is exactly the required extraction of the centrifugal extractor a7, and is recycled and used, so that the product quality is improved without generating additional waste

[0037] Those skilled in the art will understand that the embodiments of the utility model shown in the above description and the drawings are only examples and do not limit the utility model, and the purpose of the utility model has been completely and effectively achieved. The function and structural principle of the utility model have been shown and explained in the embodiments, and the embodiments of the utility model can be any deformation or modification without departing from the principle.

Claims

1. A safe production device for synthesizing 2-chloro-3-pyridylamine using high-purity chlorine, comprising a liquid chlorine gasification device, a chlorine condenser, a chlorination reactor, and a post-reaction continuous extraction device, wherein the chlorination reactor is provided with a chlorine inlet pipe, and the post-reaction continuous extraction device comprises three centrifugal extractors connected with each other. The chlorine pipe between the liquid chlorine gasification device and the post-reaction continuous extraction device is provided with a vertically connected part, the vertically connected part of the chlorine pipe is provided with a chlorine condenser, the chlorine pipe includes a main pipe and a ring pipe, the ring pipe is uniformly distributed with dispersed air holes, and the centrifugal extractor is connected to the bottom of the chlorination reactor.

2. The safe production device for synthesizing 2-chloro-3-pyridylamine by using high-purity chlorine according to claim 1, characterized in that: The device temperature of the liquid chlorine gasification device is kept above 85 DEG C, the chlorine pipe of the liquid chlorine gasification device is connected to the main pipe of the chlorine pipe, and the chlorine pipe passes through the condensing pipe in the chlorine condenser.

3. The safe production device for synthesizing 2-chloro-3-pyridylamine by using high-purity chlorine according to claim 1, characterized in that: The condensing pipe in the chlorine condenser surrounds the chlorine pipe, the chlorine condenser follows the vertical direction of the chlorine pipe and is also vertically placed.

4. The safe production device for synthesizing 2-chloro-3-pyridylamine by using high-purity chlorine according to claim 1, characterized in that: The ring pipes are all located in the chlorination reactor, the ring pipes are sleeved outside the stirring paddle of the chlorination reactor, the stirring diameter of the stirring paddle is smaller than the inner diameter of the ring pipe, that is, the ring pipe is outside the movement range of the stirring paddle.

5. The safe production device for synthesizing 2-chloro-3-pyridylamine by using high-purity chlorine according to claim 1, characterized in that: The ring pipes are sequentially located on the main pipe until the bottom of the main pipe, the ring pipes and the main pipe are communicated, the ring pipes are parallel to each other, the air holes on the ring pipes are dispersed on the ring pipes and penetrate the ring pipes.

6. The safe production device for synthesizing 2-chloro-3-pyridylamine by using high-purity chlorine according to claim 1, characterized in that: The ring pipes and the main pipe are tangent to each other, the position where the ring pipes and the main pipe are tangent to each other is communicated with the main pipe, and the ring pipe at the end of the main pipe is tangent to and communicated with the end of the main pipe.

7. The safe production device for synthesizing 2-chloro-3-pyridylamine by using high-purity chlorine according to claim 1, characterized in that: The post-reaction continuous extraction device includes a centrifugal extractor a, a centrifugal extractor b and a centrifugal extractor c, the bottom of the chlorination reactor is connected to the top of the centrifugal extractor a, the light phase of the centrifugal extractor a is connected to the top of the centrifugal extractor b, the heavy phase of the centrifugal extractor b is connected to the top of the centrifugal extractor c, and the heavy phase of the centrifugal extractor c is connected to the top of the centrifugal extractor a.

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