Production device of 3-acetamino phthalic acid

Abstract

The utility model discloses a production device of 3-acetamino phthalic acid, and belongs to the technical field of chemical production devices. The device comprises an acylation reaction device, an acidification device and a solid-liquid filtering device. The acylation reaction device comprises an acylation reaction kettle with a stirring device, an acetic anhydride high-position metering tank with a first rotor flow meter, a solid feeding hole and a first conveying pump; the acidification device comprises an acidification reaction kettle with a stirring device, a hydrochloric acid high-position metering tank with a second rotor flow meter, an online pH meter and a second delivery pump; and the solid-liquid filtering device comprises solid-liquid separation equipment, a filtrate receiving tank and a product collecting tank. All the devices of the device are connected through pipelines and stop valves. According to the utility model, the dosage of hydrochloric acid is reduced by adjusting the dosage of acetic anhydride and controlling the acidification pH value, so that the production cost is reduced, and the quality and yield of the product 3-acetamino phthalic acid are improved.

Description

Technical Field

[0001] This utility model relates to a production apparatus for 3-acetamidophthalic acid, specifically belonging to the technical field of chemical production equipment. Background Technology

[0002] 3-Acetaminophthalic acid is a white, crystalline powder, soluble in hot water and slightly soluble in cold water. This compound is commonly used as a dye intermediate and can also be used to synthesize 3-acetaminophthalic anhydride. This pharmaceutical intermediate has wide applications in many drug synthesis fields, such as the synthesis of aprexa. This drug can be used to treat psoriatic arthritis, relieving symptoms such as tendon swelling, stiffness, and pain. In March 2014, Celgene Biotechnology developed this drug, which received FDA approval in the United States. The drug is currently in clinical trials for the treatment of rheumatoid arthritis.

[0003] Currently, a synthetic process for apraxin and its intermediates mainly involves: using 3-nitrophthalic acid as the starting material and ethanol as the solvent, 3-aminophthalic acid is prepared by palladium-catalyzed hydrogenation. This is followed by reflux in acetic anhydride, followed by cooling and crystallization to obtain 3-acetamidophthalic anhydride. The resulting product is then subjected to further reactions to obtain apraxin. In this synthetic process, the reflux reaction of 3-aminophthalic acid in acetic anhydride to generate 3-acetamidophthalic anhydride uses acetic anhydride as the solvent, which poses a significant health risk to operators. Furthermore, the acetic acid and acetic anhydride subsequently produced are difficult to separate and recover. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model provides a production apparatus for 3-acetaminophthalic acid. By optimizing the process, the direct heating and reflux reaction of acetic anhydride is avoided, the amount of acetic anhydride and hydrochloric acid used is reduced, the production cost is significantly reduced, and the product quality and yield are improved.

[0005] The specific technical solution to achieve the above objectives is as follows: A production apparatus for 3-acetamidophthalic acid includes an acylation reaction apparatus, an acid precipitation apparatus, and a solid-liquid filtration apparatus; the acylation reaction apparatus includes an acylation reactor, an acetic anhydride high-level metering tank, and a solid feed inlet; the acid precipitation apparatus includes an acid precipitation reactor and a hydrochloric acid high-level metering tank; the solid-liquid filtration apparatus includes a solid-liquid separation device, a filtrate receiving tank, and a product collection tank; the acetic anhydride high-level metering tank is connected to the acylation reactor via a shut-off valve and a first rotor flow meter; the outlet of the acylation reactor is connected to the inlet of the acid precipitation reactor; the hydrochloric acid high-level metering tank is connected to the acid precipitation reactor via a shut-off valve and a second rotor flow meter; the outlet of the acid precipitation reactor is connected to the inlet of the solid-liquid separation device; and the outlet of the solid-liquid separation device is connected to the filtrate receiving tank and the product collection tank, respectively.

[0006] Furthermore, the online pH meter inside the acid precipitation reactor and the shut-off valve at the bottom of the hydrochloric acid high-level metering tank are linked to the DCS control system.

[0007] Furthermore, the acylation reactor is equipped with a jacketed cooling device, and the cooling medium of the jacketed cooling device is cold brine. The device is filled with cold water and uses chilled brine for cooling.

[0008] Furthermore, the solid-liquid separation equipment is one of a filter press, a centrifuge, or a vacuum filter tank.

[0009] Furthermore, the bottom of the acylation reactor is connected to the acid precipitation reactor via a shut-off valve and a first feed pump, and the acid precipitation reactor is connected to a solid-liquid separation device via a shut-off valve and a second feed pump.

[0010] Furthermore, the acylation reactor and the acid precipitation reactor are equipped with a stirring device.

[0011] The beneficial effects of this invention are as follows: This production apparatus reacts sodium 3-aminophthalate with acetic anhydride at low temperature in an acylation reactor to produce sodium 3-acetaminophthalate; then, acid precipitation is performed in an acid precipitation apparatus to obtain 3-acetaminophthalic acid. Subsequently, 3-acetaminophthalic acid is dehydrated intramolecularly by high-temperature reflux in a solvent to generate 3-acetaminophthalic anhydride. This avoids the harsh conditions of using acetic anhydride as a solvent for reflux in existing processes, reducing harm to operators and solving the problem of difficult separation and recovery of acetic acid and acetic anhydride. Simultaneously, the production apparatus reduces hydrochloric acid usage by adjusting the amount of acetic anhydride and controlling the pH value of the acid precipitation, lowering production costs and improving the quality and yield of the product 3-acetaminophthalic acid. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] The markings in the diagram have the following meanings: 1. Acetic anhydride high-level metering tank; 2. First rotor flow meter; 3. Solid feed inlet; 4. Acylation reactor; 5. First feed pump; 6. Hydrochloric acid high-level metering tank; 7. Second rotor flow meter; 8. Acid precipitation reactor; 9. Online pH meter; 10. DCS control system; 11. Second feed pump; 12. Solid-liquid separation equipment; 13. Filtrate receiving tank; 14. Raw material liquid feed inlet; 15. Product collection tank. Detailed Implementation

[0014] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0015] Please see Figure 1 A production apparatus for 3-acetamidophthalic acid includes an acylation reaction unit, an acid precipitation unit, and a solid-liquid filtration unit. The acylation unit is used for the acylation reaction and includes an acylation reactor 4 with a stirring device, an acetic anhydride high-level metering tank 1 with a first rotor flow meter 2, a solid feed inlet 3, and a first feed pump 5. The acid precipitation unit is used for the acid precipitation reaction of the material after the acylation reaction. This unit includes an acid precipitation reactor 8 with a stirring device, a hydrochloric acid high-level metering tank 6 with a second rotor flow meter 7, an online pH meter 9, a DCS control system 10, and a second feed pump 11. The solid-liquid filtration unit is used to separate the product and further dry it. This unit includes a solid-liquid separation device 12, a filtrate receiving tank 13, and a product collection tank 15. The specific structure is as follows: the acetic anhydride high-level metering tank 1 is connected to the acylation reactor 4 through a shut-off valve and the first rotor flow meter 2. The bottom of the acylation reactor 4 is connected to the acid precipitation reactor 8 through a shut-off valve and the first feed pump 5. The hydrochloric acid high-level metering tank 6 is connected to the acid precipitation reactor 8 through a shut-off valve and the second rotor flow meter 7. The online pH meter 9 in the acid precipitation reactor 8 and the shut-off valve at the bottom of the hydrochloric acid high-level metering tank 6 are linked with the DCS control system 10. The acid precipitation reactor 8 is connected to the solid-liquid separation equipment through a shut-off valve and the second feed pump 11. The solid-liquid separation equipment is equipped with a product outlet and a filtrate outlet, which are respectively connected to the filtrate receiving tank 13 and the product collection tank 15 through pipelines.

[0016] The acylation reaction pathway in this application is as follows: sodium 3-aminophthalate reacts with acetic anhydride at low temperature to generate sodium 3-acetaminophthalate, which is then acid-precipitated to obtain 3-acetaminophthalic acid. Subsequently, 3-acetaminophthalic acid undergoes intramolecular dehydration in a solvent under high-temperature reflux to generate 3-acetaminophthalic anhydride.

[0017] When operating using the above technical solution: The sodium 3-aminophthalate solution after reduction reaction is pumped into the acylation reactor 4 through the raw material inlet 14. The stirring device is turned on, and sodium hydrosulfite is added through the solid inlet 3. The mixture is stirred and dissolved. The acylation reactor 4 is cooled down, and anhydrous sodium carbonate is added through the solid inlet 3. Cooling continues. The lower shut-off valve of the acetic anhydride high-level metering tank 1 is opened. The acetic anhydride feeding rate is controlled by the first rotor flowmeter 2 and the shut-off valve. After feeding is complete, the reaction is maintained at a constant temperature. The lower shut-off valve of the acylation reactor 4 is opened, and the reaction solution is pumped into the acid precipitation tank through the first feed pump 5. In the reaction vessel 8, the shut-off valve at the bottom of the hydrochloric acid high-level metering tank 6 is opened. The hydrochloric acid feeding speed is controlled by the second rotor flow meter 7 and the shut-off valve. The pH value of the reaction solution is adjusted by the online pH meter 9 and the shut-off valve at the bottom of the hydrochloric acid high-level metering tank 6 in conjunction with the DCS control system 10. After the acid precipitation reaction, 3-acetaminophthalic acid is obtained. The shut-off valve at the bottom of the acid precipitation reaction vessel 8 is opened, and the solution is pumped into the solid-liquid separation device 12 by the second feed pump 11. After solid-liquid separation, 3-acetaminophthalic acid is obtained and enters the product collection tank 15. The acid precipitation filtrate enters the filtrate receiving tank 13 through the discharge valve.

[0018] A DCS (Distributed Control System) is an automated system that connects distributed control nodes through a network to achieve centralized management and decentralized control of industrial production processes. It belongs to existing technology.

[0019] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, all variations intended to fall within the meaning and scope of equivalents of the claims are encompassed within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0020] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for producing 3-acetamidophthalic acid, comprising an acylation reaction device, an acid precipitation device and a solid-liquid filtration device; the acylation reaction device comprises an acylation reaction kettle (4), an acetic anhydride high-level metering tank (1) and a solid feed inlet (3), the acid precipitation device comprises an acid precipitation reaction kettle (8) and a hydrochloric acid high-level metering tank (6), and the solid-liquid filtration device comprises a solid-liquid separation device (12), a filtrate receiving tank (13) and a product collection tank (15), characterized in that: The acetic anhydride high-level metering tank (1) is connected with the acylation reactor (4) through a stop valve and a first rotameter (2), the outlet of the acylation reactor (4) is connected with the inlet of the acid precipitation reactor (8), the hydrochloric acid high-level metering tank (6) is connected with the acid precipitation reactor (8) through a stop valve and a second rotameter (7), the outlet of the acid precipitation reactor (8) is connected with the inlet of the solid-liquid separation equipment (12), and the outlet of the solid-liquid separation equipment (12) is connected with the filtrate receiving tank (13) and the product collecting tank (15) respectively. ​ 2. The production apparatus according to claim 1, characterized by: The on-line pH meter (9) in the acid precipitation reactor (8) and the stop valve at the bottom of the hydrochloric acid high-level metering tank (6) are linked with the DCS control system (10).

3. The production apparatus according to claim 2, characterized in that: The acylation reactor (4) is provided with a jacket cooling device, and the cooling medium of the jacket cooling device is cold brine.

4. The production apparatus according to claim 3, characterized by: The solid-liquid separation equipment (12) is one of a filter press, a centrifuge and a suction filter tank.

5. The production apparatus according to claim 4, characterized in that: The bottom of the acylation reactor (4) is connected with the acid precipitation reactor (8) through a stop valve and a first feed pump (5), and the acid precipitation reactor (8) is connected with the solid-liquid separation equipment (12) through a stop valve and a second feed pump (11).

6. The production apparatus according to claim 5, characterized in that: The acylation reactor (4) and the acid precipitation reactor (8) are provided with stirring devices.

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