Method for synthesizing 1-nitroanthraquinone by using high-speed sheet-shaped horizontal reactor

Abstract

The invention belongs to the field of organic synthesis, and particularly relates to a method for synthesizing 1-nitroanthraquinone by a high-speed sheet-shaped horizontal reactor. Specifically, anthraquinone is taken as a substrate, and 1-nitroanthraquinone is generated through nitration in a high-speed sheet-shaped horizontal reactor. The device has the beneficial effects that the heat exchange area is increased, so that the nitrification heat exchange efficiency is high, and the nitrification is thorough; the problems of blockage of a continuous flow reactor, explosion easily caused by excessive temperature accumulation of a kettle type reactor, high nitrate concentration on the surface and non-uniform reaction of upper and lower layers are avoided, and the reactor is better suitable for viscous materials; the temperature of the cooling liquid of the high-speed sheet-shaped horizontal reactor is close to the reaction temperature, so that smooth reaction is guaranteed, and explosion caused by sudden reaction due to sudden reaction caused by accumulation of reactants to a certain amount due to reaction stop caused by too low temperature of a reaction medium is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly to a method for synthesizing 1-nitroanthraquinone by a high-speed sheet horizontal reactor. Background Art

[0002] 1-Nitroanthraquinone is one of the most important anthraquinone derivatives. It is the main raw material for synthesizing 1-aminoanthraquinone, which is an important intermediate for synthesizing anthraquinone dyes. It has a wide range of uses and large consumption. It can be used not only in the production of disperse, reduction, acid, and reactive dyes, but also in the production of inks, coatings, polymer pigments, and other applications. Although there are many ways to prepare 1-aminoanthraquinone, the most competitive method at present is to prepare 1-nitroanthraquinone by nitration of anthraquinone and then produce 1-aminoanthraquinone by reduction or ammonolysis.

[0003] At present, the nitration of anthraquinone mainly includes three methods: pure nitric acid nitration method, mixed acid nitration method, and solvent nitration method. In the pure nitric acid nitration method, the molar ratio of anthraquinone to nitric acid is about 1:19, the purity is not high, and the yield is 73%. The yield of the mixed acid nitration method is 75%, and the reaction system is close to a paste state, with poor fluidity and mixing property, and a long reaction time. The pure nitric acid nitration method and the mixed acid nitration method are almost phased out due to large acid consumption, low yield, and serious waste water. The solvent method is the most widely used method in industrial production at present, and the yield is about 75%-83%. At the same time, some by-products and impurities will also be obtained, and further purification is required before further application.

[0004] The invention patent with the authorized publication number CN112300003B discloses a method for synthesizing 1-nitroanthraquinone by a continuous flow microchannel reactor. This application is research and design by this unit, and a continuous flow microchannel reactor is disclosed. However, in subsequent practical applications, this technology still has some problems and deficiencies to a certain extent:

[0005] 1. The nitration heat exchange efficiency is low, resulting in incomplete nitration.

[0006] 2. The nitrate concentration on the surface is high, and the reaction between the upper and lower layers is uneven.

[0007] 3. The continuous flow microchannel reactor is prone to blockage.

[0008] 4. The cooling area is small, and the cooling water temperature is too low, resulting in the termination of the reaction. Excessive accumulation of materials is likely to cause a sudden reaction explosion.

[0009] In order to further avoid the above technical problems, this application designs a method for synthesizing 1-nitroanthraquinone by a high-speed sheet horizontal reactor to better solve the above problems. Summary of the Invention

[0010] The object of the present invention is to provide a method for synthesizing 1-nitroanthraquinone in a high-speed sheet horizontal reactor, so as to solve the problems raised in the above-mentioned background technology.

[0011] To achieve the above object, the invention provides the following technical solution: A method for synthesizing 1-nitroanthraquinone in a high-speed sheet horizontal reactor is carried out according to the following steps:

[0012] Step 1: After preheating the anthraquinone-sulfuric acid saturated solution, mixed acid nitrating agent, and organic solvent as three streams of materials respectively, they are respectively fed into the high-speed sheet horizontal reactor through metering pumps.

[0013] Step 2: Control the flow rate of the materials through metering pumps, so that the preheated anthraquinone-sulfuric acid saturated solution, mixed acid nitrating agent, and organic solvent enter the high-speed sheet horizontal reactor synchronously at the set flow rates for mixing reaction. The reaction temperature is controlled by internal and external heat exchangers, and the heat exchange medium is heat-conducting oil. The product flows out from the outlet of the reactor and enters the product collection area for further treatment.

[0014] Step 3: Dilute the material obtained at the outlet of the high-speed sheet horizontal reactor with ice water, stand for sedimentation, and separate out the sulfuric acid mother liquor; the organic phase is recovered by distillation.

[0015] Preferably, in step 1, the mass ratio of anthraquinone to sulfuric acid in the anthraquinone-sulfuric acid saturated solution is 1:3 - 5, and the mass ratio of concentrated nitric acid to sulfuric acid in the mixed acid nitrating agent is 1:2 - 4; wherein the concentration of concentrated nitric acid is 85 - 98%, and the concentration of sulfuric acid is 90 - 98%.

[0016] Preferably, the organic solvent is selected from one or more of dichloroethane, chloroform, ethyl acetate, acetone, acetonitrile, cyclohexane, N,N-dimethylformamide, and N,N-dimethylacetamide.

[0017] Preferably, the volume ratio of the organic solvent to anthraquinone is 1 - 10∶1.

[0018] Preferably, in step 2, the set flow rate of the anthraquinone-sulfuric acid saturated solution is 10 - 20 ml / min, the flow rate of the mixed acid nitrating agent solution is 2 - 7 ml / min; the flow rate of the organic solvent in step 2 is 10 - 20 ml / min; wherein the mixing reaction time in the microchannel reactor module in step 2 is 60 s - 150 s; the reaction temperature is 45°C; the reaction pressure is 0 - 5 bar.

[0019] Preferably, an external heat exchanger is coiled around the high-speed sheet horizontal reactor, and an internal heat exchanger is installed inside the high-speed sheet horizontal reactor.

[0020] Preferably, the external heat exchanger is a spiral coil pipe.

[0021] Preferably, the internal heat exchanger is a hollow stirring paddle, which includes a hollow rotating shaft. A number of hollow rotating disks are fixed on the hollow rotating shaft at equal intervals along the length direction, and a number of hollow stirring blocks are fixed on the edge of the rotating disk along the circumferential direction.

[0022] Preferably, the hollow rotating shaft, the hollow rotating disk and the hollow stirring block are connected in a through and sealed manner.

[0023] Preferably, a number of groups of scraping columns arranged along the circumferential direction are fixed on the inner wall of the high-speed sheet horizontal reactor; each group of scraping columns is located between two adjacent hollow rotating disks.

[0024] Compared with the prior art, the beneficial effects of the invention are as follows:

[0025] 1. For the method for synthesizing 1-nitroanthraquinone by using the high-speed sheet horizontal reactor, heat exchange is carried out through the provided internal and external heat exchangers, and the internal heat exchanger adopted is a hollow stirring paddle. The heat exchange medium directly passes through the hollow stirring paddle, increasing the heat exchange area, so that the nitration heat exchange efficiency is high and the nitration is thorough.

[0026] 2. For the method for synthesizing 1-nitroanthraquinone by using the high-speed sheet horizontal reactor, the internal heat exchanger adopted is a hollow stirring paddle. The hollow stirring paddle includes a hollow rotating shaft, and a number of hollow rotating disks are fixed on the hollow rotating shaft at equal intervals along the length direction. A number of hollow stirring blocks are fixed on the edge of the rotating disk along the circumferential direction, and the hollow rotating shaft, the hollow rotating disk and the hollow stirring block are connected in a through and sealed manner, further increasing the exchange area, so that the nitration heat exchange efficiency is high and the nitration is thorough, and the problems of blockage and excessive temperature accumulation leading to explosion are avoided.

[0027] 3. For the method for synthesizing 1-nitroanthraquinone by using the high-speed sheet horizontal reactor, through the provided high-speed sheet horizontal reactor, it can be evenly mixed up and down by rotating one week, avoiding the problems of high nitrate concentration on the surface and uneven reaction between the upper and lower layers.

[0028] 4. For the method for synthesizing 1-nitroanthraquinone by using the high-speed sheet horizontal reactor, a number of groups of scraping columns arranged along the circumferential direction are fixed on the inner wall of the high-speed sheet horizontal reactor; and each group of scraping columns is located between two adjacent hollow rotating disks, which is suitable for the uniform mixing of raw materials with a relatively high concentration.

[0029] 4. For the method for synthesizing 1-nitroanthraquinone by using the high-speed sheet horizontal reactor, the temperature of the coolant of the provided high-speed sheet horizontal reactor is close to the reaction temperature, ensuring the smooth progress of the reaction and avoiding the problems that the reaction stops due to too low temperature of the reaction medium and the reactants accumulate to a certain amount and suddenly react, causing a violent reaction and explosion. Description of the Drawings

[0030] Figure 1a The enhanced mass transfer channel of the heart-shaped structure of the microchannel reactor structure used in the prior art;

[0031] Figure 1b Schematic diagram of the high-speed sheet horizontal reactor structure used in the present invention;

[0032] Figure 2 Simplified flowchart of the present invention;

[0033] Figure 3 Simplified device diagram of the present invention;

[0034] Figure 4 Chromatogram of 1-nitroanthraquinone prepared by the present invention;

[0035] Figure 5 Chromatogram of 1-nitroanthraquinone prepared by the prior art.

[0036] In the figure: Wherein 1, 2, 3, 4, and 5 are raw material tanks, 6, 7, 8, 9, and 10 are raw material weighing devices, 11, 12, and 13 are mixing and preheating devices, 14, 15, and 16 are metering pumps, 17, 18, and 19 are pressure gauges, 20 is a reaction device, 21 is a product collection area, 22 is a hollow stirring paddle, and 23 is a spiral coil. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] Example 1

[0039] (1) Refer to Figure 2 to determine the connection method. The reactor channel structure is Figure 1a , and determine the molar ratio according to the channel volume and the set flow rate. The heat exchange medium of the heat exchanger is heat-conducting oil.

[0040] (2) Mix 150 g of anthraquinone and 900 g of sulfuric acid and stir to form a saturated anthraquinone-sulfuric acid solution; prepare a mixed acid solution by mixing 92.5 g of nitric acid and 370 g of sulfuric acid, with dichloroethane as the solvent. After preheating the three systems, pump them into a microchannel reactor through metering pumps at flow rates of 14 ml / min, 3.4 ml / min, and 10 ml / min respectively. At this time, the molar ratio of anthraquinone to nitric acid is 1:1.1. Control the reaction temperature at 40 °C and the residence time at 120 s. Dilute the product with ice water, settle to absorb acid, then distill out the organic phase, wash to obtain the crude product of 1-nitroanthraquinone, and detect it by liquid chromatography. The conversion rate of anthraquinone is 99%, and the HPLC purity of 1-nitroanthraquinone is 85%.

[0041] Example 2

[0042] Refer to Figure 2 Determine the connection method. The reactor channel structure is Figure 1b , and determine the molar ratio according to the channel volume and the set flow rate. The heat exchange medium of the heat exchanger is heat-conducting oil.

[0043] Mix 150 g of anthraquinone and 600 g of sulfuric acid and stir to form a saturated anthraquinone-sulfuric acid solution; prepare a mixed acid solution by mixing 92.5 g of nitric acid and 370 g of sulfuric acid, with dichloroethane as the solvent. After preheating the three systems, pump them into a microchannel reactor through metering pumps at flow rates of 12 ml / min, 4.2 ml / min, and 10 ml / min respectively. At this time, the molar ratio of anthraquinone to nitric acid is 1:1.13. Control the reaction temperature at 40 °C and the residence time at 90 s. Dilute the product with ice water, settle to absorb acid, then distill out the organic phase, wash to obtain the crude product of 1-nitroanthraquinone, and detect it by liquid chromatography. The conversion rate of anthraquinone is 99%, and the HPLC purity of 1-nitroanthraquinone is 95%.

[0044] Example 3

[0045] Refer to Figure 2 Determine the connection method. The reactor channel structure is Figure 1a , and determine the molar ratio according to the channel volume and the set flow rate. The heat exchange medium of the heat exchanger is heat-conducting oil.

[0046] Mix 150 g of anthraquinone and 600 g of sulfuric acid and stir to form a saturated anthraquinone-sulfuric acid solution; prepare a mixed acid solution by mixing 92.5 g of nitric acid and 277.5 g of sulfuric acid, with dichloroethane as the solvent. After preheating the three systems, pump them into the microchannel reactor through metering pumps at flow rates of 14 ml / min, 4.2 ml / min, and 15 ml / min respectively. At this time, the molar ratio of anthraquinone to nitric acid is 1:1.2. Control the reaction temperature at 35 °C and the residence time at 90 s. Dilute the product with ice water, settle to absorb the acid, then distill out the organic phase, wash to obtain the crude product of 1-nitroanthraquinone, and detect it by liquid chromatography. The conversion rate of anthraquinone is 99%, and the HPLC purity of 1-nitroanthraquinone is 85%.

[0047] Example 4

[0048] Refer to Figure 2 Determine the connection method. The reactor channel structure is Figure 1b , and determine the molar ratio according to the channel volume and the set flow rate. The heat exchange medium is heat-conducting oil.

[0049] Mix 150 g of anthraquinone and 600 g of sulfuric acid and stir to form a saturated anthraquinone-sulfuric acid solution; prepare a mixed acid solution by mixing 92.5 g of nitric acid and 185 g of sulfuric acid, with dichloroethane as the solvent. After preheating the three systems, pump them into the microchannel reactor through metering pumps at flow rates of 14 ml / min, 3.2 ml / min, and 15 ml / min respectively. At this time, the molar ratio of anthraquinone to nitric acid is 1:1.23. Control the reaction temperature at 45 °C and the residence time at 60 s. Dilute the product with ice water, settle to absorb the acid, then distill out the organic phase, wash to obtain the crude product of 1-nitroanthraquinone, and detect it by liquid chromatography. The conversion rate of anthraquinone is 99%, and the HPLC purity of 1-nitroanthraquinone is 95%.

[0050] Example 5

[0051] Refer to Figure 2 Determine the connection method. The reactor channel structure is Figure 1a , and determine the molar ratio according to the channel volume and the set flow rate. The heat exchange medium of the heat exchanger is heat-conducting oil.

[0052] Mix 150 g of anthraquinone and 600 g of sulfuric acid and stir to form a saturated solution of anthraquinone-sulfuric acid; prepare a mixed acid solution by mixing 92.5 g of nitric acid and 185 g of sulfuric acid, with dichloroethane as the solvent. After preheating the three systems, pump them into the microchannel reactor through metering pumps at flow rates of 20 ml / min, 4.0 ml / min, and 20 ml / min respectively. At this time, the molar ratio of anthraquinone to nitric acid is 1:1.08. Control the reaction temperature at 40 °C and the residence time at 75 s. Dilute the product with ice water, sediment and absorb the acid, then distill out the organic phase, wash to obtain the crude product of 1-nitroanthraquinone, and detect it by liquid chromatography. The conversion rate of anthraquinone is 98%, and the HPLC purity of 1-nitroanthraquinone is 85%.

[0053] Example 6

[0054] Refer to Figure 2 Determine the connection method, and the reactor channel structure is Figure 1b , and determine the molar ratio according to the channel volume and the set flow rate. The heat transfer medium is heat-conducting oil.

[0055] Mix 150 g of anthraquinone and 600 g of sulfuric acid and stir to form a saturated solution of anthraquinone-sulfuric acid; prepare a mixed acid solution by mixing 92.5 g of nitric acid and 185 g of sulfuric acid, with dichloroethane as the solvent. After preheating the three systems, pump them into the microchannel reactor through metering pumps at flow rates of 14 ml / min, 3.2 ml / min, and 15 ml / min respectively. At this time, the molar ratio of anthraquinone to nitric acid is 1:1.23. Control the reaction temperature at 45 °C and the residence time at 150 s. Dilute the product with ice water, sediment and absorb the acid, then distill out the organic phase, wash to obtain the crude product of 1-nitroanthraquinone, and detect it by liquid chromatography. The conversion rate of anthraquinone is 99%, and the HPLC purity of 1-nitroanthraquinone is 95%.

[0056] As Figure 4 is the chromatogram of 1-nitroanthraquinone prepared by the reactor channel ( Figure 1b ) structure of the present application, and the peak value of this 1-nitroanthraquinone can be obtained as 7261, t = 1 min; as Figure 5 is the chromatogram of 1-nitroanthraquinone prepared by the reactor channel ( Figure 1a ) structure of the prior art, and the peak value of this 1-nitroanthraquinone can be obtained as 6663, t = 0.5 min; use the area normalization method to determine the content (purity) of 1-nitroanthraquinone, and it can be obtained that the purity of 1-nitroanthraquinone prepared by the present application is higher than that of 1-nitroanthraquinone prepared by the prior art.

[0057] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A method for synthesizing 1-nitroanthraquinone by a high-speed sheet horizontal reactor, characterized in that It is carried out according to the following steps: Step 1: After preheating the saturated solution of anthraquinone - concentrated sulfuric acid, the mixed acid nitrating agent, and the organic solvent as three streams of materials respectively, they are fed into a high - speed sheet - type horizontal reactor through metering pumps respectively; Step 2: Control the flow rates of the materials through metering pumps, so that the preheated saturated solution of anthraquinone - concentrated sulfuric acid, the mixed acid nitrating agent, and the organic solvent enter the high - speed sheet - type horizontal reactor synchronously at the set flow rates for mixing reaction. The reaction temperature is controlled by internal and external heat exchangers, and the heat - transfer medium is thermal oil. The product flows out from the outlet of the reactor and enters the product collection area for further treatment; Step 3: Dilute the material obtained from the outlet of the high - speed sheet - type horizontal reactor with ice - water, let it stand for sedimentation, and separate out the sulfuric acid mother liquor; the organic phase is recovered by distillation.

2. The method for synthesizing 1-nitroanthraquinone by using a high-speed sheet-type horizontal reactor as described in claim 1, wherein: In the saturated solution of anthraquinone - concentrated sulfuric acid described in Step 1, the mass ratio of anthraquinone to concentrated sulfuric acid is 1:3 - 5, and in the mixed acid nitrating agent, the mass ratio of concentrated nitric acid to concentrated sulfuric acid is 1:2 - 4; wherein the concentration of the concentrated nitric acid is 85 - 98%, and the concentration of the concentrated sulfuric acid is 90 - 98%.

3. The method for synthesizing 1-nitroanthraquinone by using a high-speed sheet horizontal reactor as claimed in claim 1, wherein: The organic solvent is selected from one or more of dichloroethane, chloroform, ethyl acetate, acetone, acetonitrile, cyclohexane, N,N - dimethylformamide, and N,N - dimethylacetamide.

4. The method for synthesizing 1-nitroanthraquinone by using a high-speed sheet horizontal reactor as claimed in claim 1, wherein: The volume ratio of the organic solvent to anthraquinone is 1 - 10∶1.

5. The method for synthesizing 1-nitroanthraquinone by using a high-speed sheet horizontal reactor as claimed in claim 1, wherein: In Step 2, the set flow rate of the saturated solution of anthraquinone - concentrated sulfuric acid is 10 - 20 ml / min, the flow rate of the mixed acid nitrating agent solution is 2 - 7 ml / min; the flow rate of the organic solvent is 10 - 20 ml / min; wherein the mixing reaction time in the micro - channel reactor module in Step 2 is 60 s - 150 s; the reaction temperature is 35 - 45 °C; the reaction pressure is 0 - 5 bar.

6. The method for synthesizing 1-nitroanthraquinone by using a high-speed sheet horizontal reactor according to claim 1, wherein: An external heat exchanger is coiled around the high - speed sheet - type horizontal reactor, and an internal heat exchanger is installed inside the high - speed sheet - type horizontal reactor.

7. The method for synthesizing 1-nitroanthraquinone by using a high-speed sheet horizontal reactor as claimed in claim 6, wherein: The external heat exchanger is a spiral coil.

8. The method for synthesizing 1-nitroanthraquinone in a high-speed sheet horizontal reactor as described in claim 6, wherein: The internal heat exchanger is a hollow stirring paddle, and the hollow stirring paddle includes a hollow rotating shaft. A number of hollow rotating disks are fixed on the hollow rotating shaft at equal intervals along the length direction, and a number of hollow stirring blocks are fixed along the circumferential direction at the edge of the rotating disk.

9. The method for synthesizing 1-nitroanthraquinone by using a high-speed sheet horizontal reactor as claimed in claim 8, wherein: The hollow rotating shaft, the hollow rotating disk, and the hollow stirring block are hermetically connected in a through - hole manner.

10. A method for synthesizing 1-nitroanthraquinone using a high-speed sheet horizontal reactor as described in claim 8, characterized in that: A number of groups of scraping columns are fixed on the inner wall of the high - speed sheet - type horizontal reactor along the circumferential direction; each group of scraping columns is located between two adjacent hollow rotating disks.

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