CN111995524A - Continuous synthesis method of 5-nitroisophthalic acid - Google Patents
Continuous synthesis method of 5-nitroisophthalic acid Download PDFInfo
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Abstract
The invention relates to a continuous synthesis method of 5-nitroisophthalic acid, which is characterized by comprising the following steps: the method comprises the following steps of taking an isophthalic acid feed liquid and a nitration reagent as raw materials, and carrying out preheating, nitration reaction and quenching to obtain 5-nitroisophthalic acid; the synthesis method is carried out in a continuous reactor, raw materials are continuously added into a feed inlet of the continuous reactor, 5-nitroisophthalic acid is continuously obtained from a discharge port of the reactor, and the total reaction time is less than or equal to 20 min; the phthalic acid feed liquid can be a solution, an emulsion, a suspension or an emulsion. The invention innovatively breaks through the limitation of the traditional process and realizes the continuous synthesis of the 5-nitroisophthalic acid; the total reaction time is greatly shortened, the material quantity in the reactor is greatly reduced, and the safety is greatly improved.
Description
Technical Field
The invention belongs to the technical field of organic chemistry, relates to a preparation process of a medical intermediate, and particularly relates to a continuous synthesis method of a compound 5-nitroisophthalic acid.
Background
5-nitroisophthalic acid is a chemical intermediate commonly used in the field of organic synthesis, mainly used as a diagnostic drug flooding (X-ray contrast agent) intermediate and used as an intermediate of disperse dyes, and a synthetic process for industrially synthesizing high-purity products is not seen so far, and the structural formula is as follows:
the synthesis of 5-nitroisophthalic acid generally comprises a nitration process and an oxidation process, and the synthesis of 5-nitroisophthalic acid is illustrated below by taking 5-nitroisophthalic acid as an example: the first is to take isophthalic acid as raw material, prepare the product by nitration, the total yield is about 88%, the reaction route is as follows:
secondly, as disclosed in the Chinese patent CN107118082, the product is prepared by using 1, 3-dimethyl-5-nitrobenzene as a raw material and oxidizing the raw material by potassium permanganate, wherein the yield is 90 percent, and the reaction route is as follows:
at present, the two routes adopt an intermittent process to produce 5-nitroisophthalic acid, for example, the technologies disclosed in the first route chinese patents CN108911987A, CN107721859A, CN101967111A, CN101219958A, CN101215244A and the like, both adopt the steps of dissolving raw materials in concentrated sulfuric acid, and adding a nitrating agent dropwise at high temperature for nitration, but the nitration reaction releases heat very violently and the concentrated sulfuric acid has extremely high viscosity, so that the situations of local over-high concentration, temperature runaway, coking and the like occur in the material mixing reaction process carelessly, and more serious the situation that the nitrating product and the organic matter cause violent oxidation reaction under the situation of local over-high concentration to flush or explode. In the second route, the Chinese patent CN107118082A needs to use a strongly oxidizing potassium permanganate reagent, so that the subsequent wastewater treatment cost is high and the reaction yield is low.
The production of 5-nitroisophthalic acid by a batch or semi-batch process has the following problems:
the intermittent batch operation has low efficiency, long reaction time, poor reaction selectivity and more byproducts.
The nitration reaction has violent heat release, and under the condition of process deviation (stirring failure, cooling failure, temperature control deviation, material proportion deviation and the like), multi-nitration impurities and easily-structured impurities are easily generated, and the reaction safety risk and the quality control risk are higher.
In the batch process, after the nitration reaction is finished, the reaction kettle keeps a large amount of nitration product 5-nitroisophthalic acid with high energy content within a certain time, and has great safety risk and great potential safety hazard.
In recent years, some methods for producing other nitro compounds by using continuous stirred tank reactor reaction have been reported, for example, chinese patents CN105017024A, CN105013418A, CN106083596A and CN210620664U disclose methods for preparing nitro compounds by multi-tank series connection, however, the material of the "continuous" reaction is still waiting in each tank, the material amount in the reaction process is still not small, and intrinsic safety cannot be realized.
The synthetic route of 5-nitroisophthalic acid has been successfully developed as early as 1940, and the product has been widely applied as an important intermediate, but is limited by the current production process, so that the production safety cannot be ensured in large-scale production. Therefore, it is required to develop a continuous synthesis process of 5-nitroisophthalic acid with high purity, which is intrinsically safe, simple to operate, efficient, and easy for mass production.
Disclosure of Invention
The invention overcomes the defects of the prior art and provides a continuous flow synthesis process of 5-nitroisophthalic acid.
The continuous flow synthesis process has continuous material feeding and continuous production of the product, and the material flow is continuous, continuous and no stay waiting, so that the product is produced continuously. When the process operation reaches a steady state, the state parameters of the composition, the temperature and the like of the materials at any position in the reactor do not change along with the time, so the production process and the product quality are stable; it has the characteristics of short time consumption, high efficiency, easy operation and the like. Compared with the traditional kettle type batch process, the continuous process has great difference; not only the control requirements of the technological process but also the selection of the condition parameters; therefore, the continuous process is a brand-new developed preparation process, and the intermittent process of the same product cannot be used for reference or transplantation and cannot be applied to the intermittent process.
In order to achieve the purpose, the invention adopts the technical scheme that: a continuous synthesis method of 5-nitroisophthalic acid is provided, which is characterized in that: the method comprises the following steps of taking an isophthalic acid feed liquid and a nitration reagent as raw materials, and carrying out preheating, nitration reaction and quenching to obtain 5-nitroisophthalic acid; the synthesis method is carried out in a continuous reactor, raw materials are continuously added into a feed inlet of the continuous reactor, 5-nitroisophthalic acid is continuously obtained from a discharge port of the reactor, and the total reaction time is less than or equal to 20 min; the isophthalic acid feed liquid can be a solution, an emulsion, a suspension or an emulsion.
Wherein: the number of the feed ports of the continuous reactor may be one or more, and the number of the discharge ports may be one or more. The raw materials can be added continuously or simultaneously.
The total reaction time is the time required from the entry of the feedstock into the reactor to the exit of the product from the reactor, and may also be referred to as residence time in the present continuous flow process. Preferably, the total reaction time is 10s-20 min; more preferably 20s-15 min; most preferably 30s-3 min.
As a preferable scheme, the continuous reactor is one or a combination of more of a continuous stirred tank reactor, a microreactor, a tubular reactor, a dynamic tubular reactor and a continuous stirred microreactor; the continuous reactor comprises four temperature zones; the nitrating reagent is selected from nitroguanidine, concentrated nitric acid, fuming nitric acid or a solution obtained by mixing the nitroguanidine, the concentrated nitric acid and the fuming nitric acid with concentrated sulfuric acid.
Wherein: the concentration of the feed solution of the nitrating agent is 5 to 100 wt%, preferably 25 to 100 wt%, more preferably 45 to 100 wt%, and most preferably 65 to 100 wt%. The nitrating agent can be a liquid nitrating agent, and can also be a nitrating agent slurry liquid, a nitrating agent suspension, an emulsion and a solution.
As a more preferable scheme, the method comprises the following steps:
preparation of nitration reagent: conveying one or more of nitroguanidine, nitric acid and concentrated sulfuric acid to a first temperature zone of the continuous reactor, flowing forward therein and forming a stable state; the temperature of the first temperature zone is as follows: 0 to 110 ℃; preferably 10-100 deg.C, more preferably 20-90 deg.C.
Preheating: the isophthalic acid feed liquid and the nitration reagent prepared in the first temperature zone respectively flow to the second temperature zone, and the isophthalic acid feed liquid and the nitration reagent flow forwards and are preheated in the second temperature zone; the temperature of the second temperature zone is as follows: 10-120 ℃; preferably from 30 to 100 deg.C, more preferably from 50 to 90 deg.C.
Nitration reaction: the preheated phthalic acid feed liquid and the nitration reagent flow to a third temperature zone, and the preheated phthalic acid feed liquid and the nitration reagent flow forwards in the third temperature zone, are mixed and react to generate 5-nitroisophthalic acid; the temperature of the third temperature zone is as follows: 20-130 ℃; preferably 50-110 deg.C, more preferably 70-100 deg.C.
Quenching: the reaction liquid flowing out of the third temperature zone flows into the fourth temperature zone and conveys water to the fourth temperature zone, and the reaction liquid and the water flow forwards in one zone and carry out quenching reaction to obtain a finished product; the temperature of the fourth temperature zone is as follows: 0 to 80 ℃; preferably 2-30 deg.C, more preferably 5-10 deg.C.
As a more preferable scheme, the time of the nitration reaction is as follows: 10s-10 min.
As a more preferred embodiment, the time for quenching the reaction is: 1s-120 min.
As a preferred embodiment, the molar ratio of the isophthalic acid to the nitrating agent is 1: 1.1-3.0; preferably 1: 1.3-2.1.
In a preferred embodiment, the concentration of the isophthalic acid feed solution is not higher than 25wt%, and the solvent is sulfuric acid, an inert agent immiscible with the sulfuric acid, or a mixture of the sulfuric acid and the inert agent.
As a more preferred version, the inert, sulfuric acid-immiscible reagent comprises dichloroethane and an alkane containing seven or more carbon atoms; dichloroethane, n-heptane, n-octane, pentadecane are preferred.
More preferably, the isophthalic acid feed solution is a 15-20wt% solution or suspension of isophthalic acid in sulfuric acid.
The invention controls the generation of nitrogen oxide gas in the reaction by controlling the concentration of a nitration reagent and a phthalic acid feed liquid, the proportion of the nitration reagent to raw materials, the temperature of the material entering a nitration reaction section and the temperature of the nitration reaction section, or by adding a solvent (such as dichloroethane and pentadecane) which is easy to recycle, inert and immiscible with sulfuric acid into a substrate; the Taylor flow of gas-liquid or liquid-liquid is formed in the system, and the generation of turbulence is avoided, so that the purposes of ensuring mixing, increasing fluidity and preventing materials from depositing or crystallizing on the tube wall are achieved, and then the feeding and the reaction in the form of emulsion, turbid liquid or emulsion can be realized.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention innovatively breaks through the limitation of the traditional process and realizes the continuous synthesis of the 5-nitroisophthalic acid; continuously adding raw materials in the process, continuously producing the product, wherein the materials (reaction mixture containing the raw materials, intermediates, products, solvent and the like) continuously flow without interruption and stay for waiting; meanwhile, as the mass and heat transfer effects are greatly improved, slow dripping operation is not needed on the reaction device; therefore, the efficiency of the process is greatly improved, and the total time of the nitration reaction is controlled within 20 minutes, compared with the traditional batch process which needs at least several hours.
2. The method realizes the nitration reaction for the first time, can not only carry out continuous reaction in the form of traditional solution, but also feed in the form of emulsion, turbid liquid or emulsion, and solves the problems that most of continuous nitration reactions can not contain solid raw materials and can only carry out reaction through a continuous stirring reaction kettle.
3. The configuration of the process nitration reagent and the nitration reaction can be finished in the integrated reactor, no additional batching device and transfer device are needed, and the operation in a closed space also avoids the harm of acid mist volatilized in the experimental process to operators and the corrosion to equipment.
4. The process realizes high purity and high yield of the product while solving the application of a reaction continuous process; the process yield of the invention is as high as 85%, even more than 90%.
5. According to the invention, each process of the process is modularized, different temperature zone divisions and temperature settings are adopted, and the temperature of each zone is combined with the matching of material concentration, material proportion and material flow rate; the method breaks through the limit of the traditional process to the nitration reaction, overcomes the potential safety hazard of the nitration reaction, can realize the reaction at higher concentration and higher temperature in short time, optimizes the reaction process, improves the fluidity of the materials and realizes the continuous flow process.
6. According to the invention, the temperature zones are divided and set, so that the reaction temperature can be accurately controlled, the safety risk caused by decomposition and explosion of nitro products due to sudden rise of local temperature is avoided, the intrinsic safety of the device operation and the production process is greatly improved, and a full-continuous production mode is realized. The division of the temperature zone can also improve the energy utilization rate in industrialization.
7. Due to the implementation of continuous flow, the reactor of the present invention tends to have a very small liquid hold-up; generally, the liquid holdup (liquid holdup refers to the total volume of reaction materials existing in the reactor at any time when the operation reaches a steady state) for completing the same annual yield is only 1/1000 of the traditional tank reactor, a large amount of high-energy nitration product 5-nitroisophthalic acid cannot be kept in the process, and the process safety is greatly improved.
8. Because the liquid holdup of the reactor is small, the equipment required by the invention has small volume and small occupied area; compared with the traditional preparation process, the method greatly saves the land cost and the construction cost of a factory workshop.
9. Compared with the traditional batch process, the process has better production safety and process stability, and can realize larger production scale than the batch process.
Drawings
The invention is further illustrated with reference to the following figures and examples.
FIG. 1 is a schematic synthesis of example 1 of the present invention.
FIG. 2 is a schematic synthesis of example 2 of the present invention.
FIG. 3 is a schematic synthesis of example 3 of the present invention.
FIG. 4 is a schematic synthesis of example 4 of the present invention.
Detailed Description
The invention is further described with reference to specific examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby. Meanwhile, it is to be noted that: unless otherwise stated, the concentrations in the examples and comparative examples are mass concentrations, and the purity of the product is measured by high performance liquid chromatography.
Example 1
As shown in fig. 1, sulfuric acid and 65% concentrated nitric acid are respectively pumped to a temperature zone 1(10 ℃), and mixed acid is formed; the flow rate of nitric acid is 2mL/min, and the flow rate of sulfuric acid is 2 mL/min. A solution of isophthalic acid in sulfuric acid (12 wt%) was pumped to zone 2 to preheat to 50 deg.C at a flow rate of 10 mL/min. Then, the sulfuric acid solution of the isophthalic acid and the mixed acid are conveyed into a tubular reactor for nitration reaction (temperature zone 3,75 ℃), and the reaction retention time is 4 min. The reaction liquid flows out and enters a continuous stirring micro-reactor to be quenched by water (temperature zone 4, 10 ℃), the flow rate of the pumped water is 15mL/min, and the quenching residence time is 5 min. After the system reached steady state, a 20 minute sample was collected. The effluent slurry was filtered, washed with water, and vacuum dried at 60 ℃ to give 47.5 g of a product with a purity of 99.2% and a yield of 90%.
Example 2
As shown in fig. 2, a sulfuric acid solution (15 wt%) of isophthalic acid is preheated to 80 ℃ through a temperature zone 2, and then pumped into a microchannel reactor together with fuming nitric acid (temperature zone 1, room temperature) respectively for nitration reaction (temperature zone 3,95 ℃); the flow rate of the sulfuric acid solution of the isophthalic acid is 40mL/min, the flow rate of the nitric acid is 5mL/min, and the reaction residence time is 50 s. The effluent reaction liquid enters a dynamic tubular reactor and is quenched by water (temperature zone 4, 10 ℃), the flow rate of pumped water is 80mL/min, and the quenching retention time is 10 min. After the system reached steady state, a 30 minute sample was collected. The effluent slurry was filtered, washed with water, and vacuum dried at 60 ℃ to give 348.1 g of product with 99.5% purity and 88% yield.
Example 3
As shown in FIG. 3, sulfuric acid slurry of isophthalic acid (20 wt%, temperature zone 2, 60 ℃) and fuming nitric acid (temperature zone 1, room temperature) were pumped into a dynamic tubular reactor respectively for nitration reaction (temperature zone 3,85 ℃); the flow rate of the isophthalic acid sulfuric acid solution is 120mL/min, the flow rate of the nitric acid is 20mL/min, and the reaction residence time is 1min after mixing. The effluent reaction solution enters a continuous stirring reaction kettle and is quenched by water ( temperature zone 4, 5 ℃), and the flow rate of pumped water is 360 mL/min. The effluent quenching liquid enters a crystallization kettle, and a sample flowing out of the crystallization kettle enters a filtering device. After the system reached steady state, 30 minutes of product was collected. The product is washed by water and dried in vacuum at 60 ℃ to obtain 1360.5 g of product with the purity of 99.6 percent and the yield of 86 percent.
Example 4
As shown in fig. 4, a sulfuric acid solution (11 wt%) of isophthalic acid is preheated to 50 ℃ through a temperature zone 2, and then pumped into a microchannel reactor together with fuming nitric acid (temperature zone 1, 80 ℃) to carry out nitration reaction (temperature zone 3,85 ℃); the flow rate of the isophthalic acid sulfuric acid solution is 20mL/min, the flow rate of the nitric acid is 2mL/min, and the reaction residence time is 0.5 min. The effluent reaction liquid enters a tubular reactor (temperature zone 3,85 ℃), and the reaction is continued for 0.5 min. The reaction solution flowed into the continuous stirred tank reactor and quenched with water ( temperature zone 4, 5 ℃), and the flow rate of pumped water was 60 mL/min. The effluent quenching liquid enters a crystallization kettle, and a sample flowing out of the crystallization kettle enters a filtering device. After the system reached steady state, 5 minutes of product was collected. The product is washed by water and dried in vacuum at 80 ℃ to obtain 21.1 g of product with the purity of 99.8 percent and the yield of 87 percent.
Examples 5 to 10
Conveying 65% concentrated nitric acid (raw material 2) and 98% concentrated sulfuric acid (raw material 3) into a temperature zone 1(15 ℃) by using a constant flow pump, and finishing the preparation of a nitration reagent (mixed acid) after flowing through the temperature zone 1. The isophthalic acid feed liquid (raw material 1) is conveyed to a temperature zone 2(50 ℃) by using a constant flow pump for preheating. The phthalic acid feed liquid and the nitrating reagent are mixed and react at a temperature zone of 3(85 ℃). Quenching the reaction mixture and water flowing into a temperature zone 4(5 ℃), cooling, crystallizing, filtering and drying to obtain the product 5-nitroisophthalic acid. The respective reaction parameters and results are shown in table 1.
TABLE 1 examples 5-10 proportions of the respective raw materialsaFlow rate, purity and yield of the product
a the concentrations of the starting materials used in the actual synthesis deviate by mass from the concentrations listed in the table by. + -. 1 percentage points.
b the flow rates of the raw materials used in the actual synthesis deviate by + -2% from the flow rates listed in the table.
c the reaction residence time in the actual synthesis deviates by + -15% from the total reaction time listed in the table.
d, after quenching the reaction, cooling the dichloroethane in a quenching kettle, and flowing out through an overflow port on the quenching kettle for recycling.
e, after quenching the reaction, the pentadecane can flow out of an overflow port on the quenching kettle and be recycled and reused; the mass ratio of the sulfuric acid to the pentadecane is 1: 18.
Examples 11 to 21
The preparation of examples 11-21 was substantially similar to that of examples 5-10, except that the starting materials and process parameters were varied, as specified in tables 2 and 3; wherein the raw material 1 is a concentrated sulfuric acid solution of isophthalic acid. T1 represents temperature zone 1, T2 represents temperature zone 2, T3 represents temperature zone 3, and T4 represents temperature zone 4.
TABLE 2 compounding ratio of each raw material in examples 11 to 16aFlow rate and equivalence ratio
aThe mass concentration of the starting material 1 in the actual synthesis was 11%, and the concentration of the starting material used was within. + -. 1% of the concentration listed in the tableDeviation of quantitative concentration.
bThe flow rates of the starting materials used in the actual synthesis deviate by + -2% from the flow rates listed in the table.
cThe total reaction time in the actual synthesis deviates by + -15% from the total reaction time listed in the table.
TABLE 3 proportioning of raw materials of examples 17 to 21aFlow rate and equivalence ratio
aThe mass concentration of the raw material 1 in the actual synthesis was 11%, and the concentration of the raw material used was deviated from the concentration listed in the table by a mass concentration of ± 1 percentage point.
bThe flow rates of the starting materials used in the actual synthesis deviate by + -2% from the flow rates listed in the table.
cThe total reaction time in the actual synthesis deviates by + -15% from the total reaction time listed in the table.
Comparative example 1
Weighing 10.6g of 65% concentrated nitric acid, controlling the temperature to be 0-5 ℃, dripping into 10.6mL of concentrated sulfuric acid, finishing dripping within about 20 minutes, and preparing mixed acid for later use.
Weighing 10g of isophthalic acid, adding the isophthalic acid into 30mL of concentrated sulfuric acid, wherein the isophthalic acid cannot be completely dissolved at room temperature, heating to 60 ℃, stirring and dissolving, slowly dropwise adding the mixed acid obtained in the previous step into a concentrated sulfuric acid solution of the isophthalic acid, finishing dropwise adding within about 15min, heating the internal temperature from 60 ℃ to 65 ℃ in the dropwise adding process, heating to 90 ℃, keeping the temperature and stirring for 40 min, after the reaction is finished, slowly dropwise adding the reaction system into 100mL of an ice-water mixture, controlling the internal temperature to be not more than 20 ℃, stirring for 30 min at room temperature, filtering, washing with 200mL of water of a filter cake, and performing vacuum drying for 12 h at 50 ℃ to obtain 10.8g of 5-nitroisophthalic acid, wherein the liquid phase purity is 99.4%. The yield thereof was found to be 84%.
Comparative example 2
Weighing 10g of isophthalic acid, adding the isophthalic acid into 30mL of concentrated sulfuric acid, not completely dissolving at room temperature, heating to 60 ℃, stirring to dissolve, slowly dropwise adding 7g of fuming nitric acid into a concentrated sulfuric acid solution of the isophthalic acid, ending dropwise adding for about 15min, heating the internal temperature from 60 ℃ to 65 ℃ in the dropwise adding process, keeping the temperature and stirring for 180 min, after the reaction is finished, slowly dropwise adding a reaction system into 100mL of an ice-water mixture, controlling the internal temperature to be not more than 20 ℃, stirring for 30 min at room temperature, filtering, washing a filter cake with 200mL of water, and drying in vacuum at 50 ℃ for 12 h to obtain 10.5g of 5-nitroisophthalic acid, wherein the liquid phase purity is 99.3%. The yield thereof was found to be 83%.
Compared with the comparative example, the embodiment of the invention can find that the total reaction time is controlled within 20 minutes, compared with the traditional intermittent process, the total reaction time (at least several hours) is greatly shortened, the reaction efficiency is greatly improved, the material quantity in the reactor is greatly reduced, and the safety is greatly improved; meanwhile, the purity and the yield of the product are slightly improved.
In light of the foregoing description of the preferred embodiment of the present invention, it is to be understood that various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.
Claims (9)
- The continuous synthesis method of 1.5-nitroisophthalic acid is characterized by comprising the following steps: the method comprises the following steps of taking an isophthalic acid feed liquid and a nitration reagent as raw materials, and carrying out preheating, nitration reaction and quenching to obtain 5-nitroisophthalic acid; the synthesis method is carried out in a continuous reactor, raw materials are continuously added into a feed inlet of the continuous reactor, 5-nitroisophthalic acid is continuously obtained from a discharge port of the reactor, and the total reaction time is less than or equal to 20 min; the phthalic acid feed liquid can be a solution, an emulsion, a suspension or an emulsion.
- 2. The continuous synthesis process of 5-nitroisophthalic acid according to claim 1, characterized in that: the continuous reactor is one or a combination of a plurality of continuous stirred tank reactors, microreactors, tubular reactors, dynamic tubular reactors and continuous stirred microreactors; the continuous reactor comprises four temperature zones; the nitrating reagent is selected from nitroguanidine, concentrated nitric acid, fuming nitric acid or a solution obtained by mixing the nitroguanidine, the concentrated nitric acid and the fuming nitric acid with concentrated sulfuric acid.
- 3. The continuous synthesis process of 5-nitroisophthalic acid according to claim 2, characterized in that: the method comprises the following steps:preparation of nitration reagent: conveying one or more of nitroguanidine, nitric acid and concentrated sulfuric acid to a first temperature zone of the continuous reactor, flowing forward therein and forming a stable state; the temperature of the first temperature zone is as follows: 0 to 110 ℃;preheating: the isophthalic acid feed liquid and the nitration reagent prepared in the first temperature zone respectively flow to the second temperature zone, and the isophthalic acid feed liquid and the nitration reagent flow forwards and are preheated in the second temperature zone; the temperature of the second temperature zone is as follows: 10-120 ℃;nitration reaction: the preheated phthalic acid feed liquid and the nitration reagent flow to a third temperature zone, and the preheated phthalic acid feed liquid and the nitration reagent flow forwards in the third temperature zone, are mixed and react to generate 5-nitroisophthalic acid; the temperature of the third temperature zone is as follows: 20-130 ℃;quenching: the reaction liquid flowing out of the third temperature zone flows into the fourth temperature zone and conveys water to the fourth temperature zone, and the reaction liquid and the water flow forwards together and carry out quenching reaction to obtain a finished product; the temperature of the fourth temperature zone is as follows: 0 to 80 ℃.
- 4. The continuous synthesis process of 5-nitroisophthalic acid according to claim 3, characterized in that: the time of the nitration reaction is as follows: 10s-10 min.
- 5. The continuous synthesis process of 5-nitroisophthalic acid according to claim 3, characterized in that: the time of the quenching reaction is as follows: 1s-120 min.
- 6. A continuous process for the synthesis of 5-nitroisophthalic acid as claimed in any of claims 1 to 5, characterized in that: the molar ratio of the isophthalic acid to the nitrating agent is 1: 1.1-3.0.
- 7. A continuous process for the synthesis of 5-nitroisophthalic acid as claimed in any of claims 1 to 5, characterized in that: the concentration of the isophthalic acid feed liquid is not higher than 25wt%, and the solvent is sulfuric acid, an inert reagent immiscible with the sulfuric acid and a mixture of the sulfuric acid and the inert reagent.
- 8. The continuous synthesis process of 5-nitroisophthalic acid according to claim 7, characterized in that: the inert reagent immiscible with sulfuric acid includes dichloroethane and alkanes containing seven or more carbon atoms.
- 9. The continuous synthesis process of 5-nitroisophthalic acid according to claim 7, characterized in that: the isophthalic acid feed liquid is 15-20wt% isophthalic acid sulfuric acid solution or suspension.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108911987A (en) * | 2018-05-25 | 2018-11-30 | 江苏道博化工有限公司 | A kind of synthesis technology of 5- nitro-isophthalic acid |
| CN111153803A (en) * | 2020-02-11 | 2020-05-15 | 浙江聚贤医药科技有限公司 | Method for synthesizing 5-nitroisophthalic acid |
-
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108911987A (en) * | 2018-05-25 | 2018-11-30 | 江苏道博化工有限公司 | A kind of synthesis technology of 5- nitro-isophthalic acid |
| CN111153803A (en) * | 2020-02-11 | 2020-05-15 | 浙江聚贤医药科技有限公司 | Method for synthesizing 5-nitroisophthalic acid |
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| CN113185418A (en) * | 2021-05-13 | 2021-07-30 | 山东师范大学实验厂 | Continuous flow production process of haematochrome B |
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| CN116023268A (en) * | 2022-12-12 | 2023-04-28 | 深圳智微通科技有限公司 | Method for preparing 5-nitroisophthalic acid by continuous nitration |
| CN117000168A (en) * | 2023-09-26 | 2023-11-07 | 天津凯莱英医药科技发展有限公司 | Continuous synthesis system and method of 2-nitro-3-methylbenzoic acid |
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