Sulfadimidine sodium production method and microchannel reactor thereof
Through multi-step reaction and microchannel reactor technology, the low yield and instability of the sulfamide sodium production method in the prior art are solved, and an efficient and stable production process and high-quality products are achieved.
Patent Information
- Application Number
- CN202510157834.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-13
- Publication Date
- 2025-05-23
AI Technical Summary
There is a lack of effective production methods for sodium sulfamethrin in the prior art, resulting in low yields and unstable quality.
A production method including a multi-step reaction is adopted, firstly by reacting p-aminobenzenesulfonamide and acetic anhydride to form acesulfonamide, then reacting with halogen to form ap-halogenated acesulfonamide, then condensation with 2,4-dimethylpyrimidine, and finally a mixture reaction of sodium hydroxide solution and sulfadimethylpyrimidine in a microchannel reactor to produce sodium sulfadimethylpyrimidine.
The high yield, high quality and good stability of sodium sulfamethrin is achieved, and the efficiency of the reaction and the purity of the product are improved through the use of the microchannel reactor.
Smart Images
Figure CN120022823A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fine chemical industry, and in particular to a method for producing sulfadimethoxine sodium and a microchannel reactor thereof. Background Art
[0002] Sulfadimethoxine sodium is a white or milky white crystalline powder, odorless or almost odorless, easily soluble in water and slightly soluble in ethanol. It is an antibacterial sulfonamide. Sulfadimethoxine sodium is used to treat infections caused by meningitis, pneumococci, hemolytic streptococci and certain Gram-negative bacilli. The specific preparation method of sulfadimethoxine hydrogen sulfate has not been disclosed.
[0003] Based on this, the present invention provides a method for producing sulfadimethoxine sodium and a microchannel reactor thereof. Summary of the invention
[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a method for producing sulfadimethazine sodium and a microchannel reactor thereof.
[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A method for producing sulfadimethoxine sodium comprises the following steps: Step 1: p-aminobenzenesulfonamide reacts with acetic anhydride in the presence of a catalyst at a temperature of 50-60° C. for 1-3 hours to generate acetylsulfonamide; Step 2: adding acetylsulfonamide to chloroform, and then contacting with halogen to react under the action of light or an initiator, the reaction temperature is 30-60° C., the time is 2-6 hours, and p-halogenated acetylsulfonamide is generated; Step 3: adding p-haloacetylsulfonamide and 2,4-dimethylpyrimidine to an organic solvent, and then adding an alkaline substance, and carrying out a condensation reaction under alkaline conditions at a reaction temperature of 80-120° C. for 4-8 hours to obtain a condensation product; Step 4: adding an alkaline substance to the condensation product, hydrolyzing the acetyl group in the condensation product to regenerate the amino group, then mixing the sulfadimethazine with a sodium hydroxide solution, and then entering the microchannel reactor for reaction, wherein the temperature in the microchannel reactor is 78-82° C., the residence time is 20-30 seconds, and the pressure is lower than 2.0 MPa to generate sulfadimethazine sodium; Step 5: The finished product of sulfadimethazine sodium is obtained by crystallization, filtration and drying.
[0006] Preferably, the catalyst is pyridine.
[0007] Preferably, the halogen is bromine or chlorine.
[0008] Preferably, the alkaline substance is one or more of potassium carbonate and sodium carbonate.
[0009] A microchannel reactor used in a method for producing sulfadimethoxine sodium, wherein the microchannel reactor is the microchannel reactor in step 4, and the microchannel reactor comprises a shell: Circular baffles are fixedly connected to both ends of the inner wall of the shell, and multiple groups of heat transfer tubes are fixedly connected between the circular baffles; The left and right ends of the shell are respectively fixedly connected with a first outer cover and a second outer cover, and the upper and lower ends of the second outer cover are respectively fixedly connected with a material inlet pipe for feeding and a circular partition for discharging; A material partition is fixedly connected to the middle end of the inner wall of the second outer cover, and the material partition is fixedly connected to the circular partition near the end of the second outer cover; A buffer component for stabilizing flow is fixedly connected to the side wall of the second outer cover, and the buffer component is located above the material partition plate; The inner wall of the shell is provided with a flow guide component for cleaning the outer wall of the heat transfer tube and guiding the heating medium in an S-shaped trajectory; the flow guide component is fitted and slidably connected with the outer wall of the heat transfer tube; The end of the first outer cover is fixedly connected with a flow disturbance cleaning component for driving the flow guide component to move back and forth and for disturbing the inner wall of the heat transfer tube and the material in the heat transfer tube. The flow disturbance cleaning component is slidably connected with the inner wall of the heat transfer tube; The spoiler cleaning component is fixedly connected to the guide component, and the portion of the guide component close to the spoiler cleaning component is slidably connected to the sliding hole formed in the circular partition on the left side; A heating medium inlet pipe for the heating medium to enter is fixedly connected to the top of one end of the shell, and a heating medium outlet pipe for the heating medium to flow out is fixedly connected to the bottom of the other end of the shell.
[0010] Preferably, the buffer assembly includes a third outer cover, a slide rod, a spring and a piston. The third outer cover is communicated with and fixedly connected to the second outer cover, and the third outer cover is located above the material partition. The outer end of the third outer cover is slidably connected to the slide rod through a slide hole, and the inner end of the slide rod is fixedly connected to the piston. A spring is fixedly connected between the side wall of the piston close to the slide rod and the inner wall of the end of the third outer cover away from the shell, and the outer wall of the piston is slidably connected to the inner wall of the third outer cover.
[0011] Preferably, the guide assembly includes an upper semicircular plate, a second cross bar, an upper scraper, a lower scraper and a lower semicircular plate, the bottom of the upper semicircular plate is fixedly connected to multiple groups of lower scrapers, the top of the lower semicircular plate is fixedly connected to multiple groups of upper scrapers, the upper semicircular plate, the upper scraper, the lower scraper and the lower semicircular plate are all slidably connected to the outer wall of the heat transfer tube through the sliding holes opened, and the upper semicircular plate and the lower semicircular plate are staggered, the upper semicircular plate is slidably connected to the upper inner wall of the shell, the lower semicircular plate is slidably connected to the lower half of the inner wall of the shell, the upper semicircular plate, the upper scraper, the lower scraper and the lower semicircular plate are all fixedly connected to the second cross bar, the second cross bar is slidably connected to the sliding holes opened in the circular partition on the left, and the second cross bar is fixedly connected to the spoiler cleaning assembly.
[0012] Preferably, the spoiler cleaning assembly includes a cylinder, a first cross bar, a circular plate, an annular scraper and a spoiler assembly. The cylinder is fixedly connected to the first outer cover, and the output end of the cylinder passes through the first outer cover and is fixedly connected to the circular plate. The outer wall of the circular plate is fitted and slidably connected to the inner wall of the first outer cover. The circular plate is fixedly connected to multiple groups of first cross bars near the inner wall of the shell. Multiple groups of spoiler assemblies are evenly spaced on the first cross bar. The multiple groups of spoiler assemblies are spirally arranged along the axial direction of the first cross bar. The annular scraper is fitted and slidably connected to the inner wall of the heat transfer tube. The annular scrapers are arranged at equal intervals, and the annular scraper is fixedly connected to the spoiler assembly.
[0013] Preferably, the circular plate is fixedly connected to the second cross bar.
[0014] Preferably, the spoiler assembly includes a plurality of groups of oblique spoilers, the outer wall of the first cross bar is fixedly connected with the oblique spoilers at equal intervals along the circumferential direction, and the annular scraper is fixedly connected to the oblique spoilers.
[0015] The beneficial effects are: 3. The sulfamethazine sodium of the present invention has high yield, good quality and good stability.
[0016] The heating medium of the heating device of the present invention enters the shell through the heating medium inlet pipe and then flows back to the heating device through the heating medium outlet pipe. The heating medium heats the heat transfer tube in the shell. The product of the condensation reaction enters the heat transfer tube on the upper side of the material partition through the material inlet pipe and the material partition. The buffer component controls the material above the material partition to perform constant pressure control, reduces the pulsating flow generated by the logistics entering the second outer cover, is conducive to the stability of the fluid in the heat transfer tube, is conducive to stable reaction, and then enters the heat transfer tube below the material partition through the first outer cover. The heated heat transfer tube heats the material in the heat transfer tube. During heating, the reacted materials are discharged through the circular partition. During heating, the turbulence cleaning component turbules the materials in the heat transfer tube, which is beneficial to the full mixing of the materials in the heat transfer tube, and is beneficial to the efficient reaction, and can also reduce the adhesion and blockage of high-viscosity materials. In addition, the turbulence cleaning component moves in the heat transfer tube, and can scrape off the materials adhered to the inner wall of the heat transfer tube, and further scrape off the materials adhered to the inner wall of the heat transfer tube. The movement of the turbulence cleaning component drives the movement of the guide component, and the guide component scrapes off the impurities adhered to the outer wall of the heat transfer tube, so as to avoid the impurities affecting the heat transfer of the heat transfer tube and ensure the heat transfer performance of the heat transfer tube. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 The microchannel reactor structure proposed by the present invention is Figure 1 ; Figure 2 A front view of the microchannel reactor structure proposed by the present invention; Figure 3 It is a right view of the microchannel reactor structure proposed by the present invention; Figure 4The microchannel reactor structure proposed by the present invention is Figure 2 ; Figure 5 For along Figure 2 AA direction cross-sectional view; Figure 6 For along Figure 3 BB direction cross-sectional view; Figure 7 It is a schematic diagram of the structure of the microchannel reactor of the present invention after removing part of the shell; Figure 8 Schematic diagram of the first cross bar and its connection structure.
[0018] In the figure: 1. shell 2. first outer cover 3. second outer cover 4. spoiler cleaning assembly 41. cylinder 42. first cross bar 43. circular plate 44. annular scraper 45. oblique spoiler 5. heating medium inlet pipe 6. material inlet pipe 7. heating medium outlet pipe 8. buffer assembly 81. third outer cover 82. slide bar 83. spring 84. piston 9. flow guide assembly 91. upper semicircular plate 92. second cross bar 93. upper scraper 94. lower scraper 95. lower semicircular plate 10. heat transfer tube 11. material partition 12. circular partition. DETAILED DESCRIPTION
[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Example
[0020] A method for producing sulfadimethoxine sodium comprises the following steps: Step 1: p-aminobenzenesulfonamide reacts with acetic anhydride in the presence of a catalyst at a temperature of 50° C. for 3 hours to generate sulfacetamide; Step 2: adding acetylsulfonamide to chloroform, and then contacting with halogen to react under the action of light or an initiator, the reaction temperature is 45° C., the time is 4 hours, and p-halogenated acetylsulfonamide is generated; Step 3: adding halogenated acetyl sulfonamide and 2,4-dimethylpyrimidine to an organic solvent, and then adding an alkaline substance, and carrying out a condensation reaction under alkaline conditions at a reaction temperature of 90° C. for 7 hours to obtain a condensation product; Step 4: adding an alkaline substance to the condensation product, hydrolyzing the acetyl group in the condensation product to regenerate the amino group, then mixing the sulfadimethazine with a sodium hydroxide solution, and then entering the microchannel reactor for reaction, the temperature in the microchannel reactor is 80° C., the residence time is 25 seconds, and the pressure is 1.8 MPa to generate sulfadimethazine sodium; Step 5: The finished product of sulfadimethazine sodium is obtained by crystallization, filtration and drying.
[0021] The catalyst is pyridine.
[0022] Halogen is bromine or chlorine.
[0023] The alkaline substance is one or more of potassium carbonate and sodium carbonate. Example
[0024] A method for producing sulfadimethoxine sodium comprises the following steps: Step 1: p-aminobenzenesulfonamide reacts with acetic anhydride in the presence of a catalyst at a temperature of 55° C. for 2 hours to generate sulfacetamide; Step 2: adding acetylsulfonamide to chloroform, and then contacting with halogen to react under the action of light or an initiator, the reaction temperature is 30° C., the time is 6 hours, and p-halogenated acetylsulfonamide is generated; Step 3: adding halogenated acetyl sulfonamide and 2,4-dimethylpyrimidine to an organic solvent, and then adding an alkaline substance, and carrying out a condensation reaction under alkaline conditions at a reaction temperature of 80° C. for 4 hours to obtain a condensation product; Step 4: adding an alkaline substance to the condensation product, hydrolyzing the acetyl group in the condensation product to regenerate the amino group, then mixing the sulfadimethazine with a sodium hydroxide solution, and then entering the microchannel reactor for reaction, the temperature in the microchannel reactor is 78° C., the residence time is 30 seconds, and the pressure is 1.6 MPa to generate sulfadimethazine sodium; Step 5: The finished product of sulfadimethazine sodium is obtained by crystallization, filtration and drying.
[0025] The catalyst is pyridine.
[0026] Halogen is bromine or chlorine.
[0027] The alkaline substance is one or more of potassium carbonate and sodium carbonate. Example
[0028] A method for producing sulfadimethoxine sodium comprises the following steps: Step 1: p-aminobenzenesulfonamide reacts with acetic anhydride in the presence of a catalyst at a temperature of 60° C. for 1 h to generate acetylsulfonamide; Step 2: adding acetylsulfonamide to chloroform, and then contacting with halogen to react under the action of light or an initiator, the reaction temperature is 60° C., the reaction time is 3 hours, and p-halogenated acetylsulfonamide is generated; Step 3: adding halogenated acetyl sulfonamide and 2,4-dimethylpyrimidine to an organic solvent, and then adding an alkaline substance, and carrying out a condensation reaction under alkaline conditions at a reaction temperature of 120° C. for 8 hours to obtain a condensation product; Step 4: adding an alkaline substance to the condensation product, hydrolyzing the acetyl group in the condensation product to regenerate the amino group, then mixing the sulfadimethazine with a sodium hydroxide solution, and then entering the microchannel reactor for reaction, the temperature in the microchannel reactor is 82° C., the residence time is 20 seconds, and the pressure is 1.85 MPa to generate sulfadimethazine sodium; Step 5: The finished product of sulfadimethazine sodium is obtained by crystallization, filtration and drying.
[0029] The catalyst is pyridine.
[0030] Halogen is bromine or chlorine.
[0031] The alkaline substance is one or more of potassium carbonate and sodium carbonate.
[0032] The sulfamethazine sodium provided by the invention has high yield, good quality and good stability. Example
[0033] Reference Figure 1-8 As shown, a microchannel reactor used in a method for producing sulfadimethazine sodium, the microchannel reactor is the microchannel reactor in step 4, and the microchannel reactor includes a housing 1: Circular baffles 12 are fixedly connected to both left and right ends of the inner wall of the shell 1, and multiple groups of heat transfer tubes 10 are fixedly connected between the circular baffles 12; The left and right ends of the shell 1 are respectively fixedly connected with a first outer cover 2 and a second outer cover 3, and the upper and lower ends of the second outer cover 3 are respectively fixedly connected with a material inlet pipe 6 for feeding and a circular partition plate 12 for discharging; A material partition plate 11 is fixedly connected to the middle end of the inner wall of the second outer cover 3, and the material partition plate 11 is fixedly connected to a circular partition plate 12 close to the end of the second outer cover 3; The side wall of the second outer cover 3 is connected and fixedly connected with a buffer component 8 for stabilizing the flow, and the buffer component 8 is located above the material partition plate 11; The inner wall of the shell 1 is provided with a flow guide component 9 for cleaning the outer wall of the heat transfer tube 10 and guiding the heating medium in an S-shaped track; the flow guide component 9 is fitted and slidably connected with the outer wall of the heat transfer tube 10; The end of the first outer cover 2 is fixedly connected with a flow disturbance cleaning component 4 for driving the flow guide component 9 to move back and forth and for disturbing the inner wall of the heat transfer tube 10 and the material in the heat transfer tube 10. The flow disturbance cleaning component 4 is slidably connected with the inner wall of the heat transfer tube 10; The spoiler cleaning component 4 is fixedly connected to the guide component 9, and the portion of the guide component 9 close to the spoiler cleaning component 4 is slidably connected to the sliding hole opened in the circular partition 12 on the left side; A heating medium inlet pipe 5 for the heating medium to enter is fixedly connected to the top of one end of the shell 1, and a heating medium outlet pipe 7 for the heating medium to flow out is fixedly connected to the bottom of the other end of the shell 1; The heating medium inlet pipe 5 is connected to the output end of the heating device, and the heating medium outlet pipe 7 is connected to the input end of the heating device; The material inlet pipe 6 is connected to the output end of the equipment for condensation reaction, and the circular partition plate 12 is connected to the input end of the equipment for crystallization; The heating medium of the heating device enters the shell 1 through the heating medium inlet pipe 5 and then flows back to the heating device through the heating medium outlet pipe 7. The heating medium heats the heat transfer tube 10 in the shell 1. The product of the condensation reaction enters the heat transfer tube 10 on the upper side of the material partition 11 through the material inlet pipe 6 and the material partition 11. The buffer component 8 controls the material above the material partition 11 to have a constant pressure, thereby reducing the pulsating flow generated when the logistics enters the second outer cover 3, which is beneficial to the stability of the fluid in the heat transfer tube 10 and the stable reaction. Then, the product enters the heat transfer tube 10 below the material partition 11 through the first outer cover 2. The heated heat transfer tube 10 heats the material in the heat transfer tube 10. During heating, the reacted materials are discharged through the circular partition 12. During heating, the turbulent cleaning component 4 turbules the materials in the heat transfer tube 10, which is beneficial to the full mixing of the materials in the heat transfer tube 10, which is beneficial to the efficient reaction and can reduce the adhesion and blockage of high-viscosity materials. In addition, the turbulent cleaning component 4 moves in the heat transfer tube 10 to scrape off the materials adhered to the inner wall of the heat transfer tube 10. The materials adhered to the inner wall of the heat transfer tube 10 are further scraped off. The movement of the turbulent cleaning component 4 drives the flow guide component 9 to move. The flow guide component 9 scrapes off the impurities adhered to the outer wall of the heat transfer tube 10 to prevent the impurities from affecting the heat transfer of the heat transfer tube 10 and ensure the heat transfer performance of the heat transfer tube 10. The buffer assembly 8 includes a third outer cover 81, a slide bar 82, a spring 83 and a piston 84. The third outer cover 81 is connected to the second outer cover 3 and is fixedly connected. The third outer cover 81 is located above the material partition 11. The outer end of the third outer cover 81 is slidably connected to the slide bar 82 through a slide hole. The inner end of the slide bar 82 is fixedly connected to the piston 84. A spring 83 is fixedly connected between the side wall of the piston 84 close to the slide bar 82 and the inner wall of the end of the third outer cover 81 away from the shell 1. The outer wall of the piston 84 is slidably connected to the inner wall of the third outer cover 81. The outer wall of the piston 84 is in close contact and sliding connection with the third outer cover 81 through an embedded sealing ring; When the material flow rate in the material inlet pipe 6 is at the set flow rate, the spring 83 is in a compressed state; When the material flow rate in the material inlet pipe 6 is at the set flow rate, the pressure value formed by the material above the material partition 11 is constant, and the pressure is in the set state, the spring 83 is in a compressed state, and when the material inlet pipe 6 flow rate decreases, the pressure above the material partition 11 decreases, and the restoring force of the spring 83 drives the piston 84 to move toward the shell 1, and the piston 84 pushes the material to flow into the shell 1, and the material pressure above the material partition 11 increases to the set state; when the material inlet pipe 6 flow rate increases, the pressure above the material partition 11 increases, and the material above the material partition 11 pushes the piston 84 to move away from the shell 1, and the material above the material partition 11 flows into the third outer cover 81, and the material pressure above the material partition 11 is reduced to the set state, so as to realize constant pressure control of the material above the material partition 11, reduce the pulsating flow generated by the logistics entering the second outer cover 3, and facilitate the stability of the fluid in the heat transfer tube 10 and the stable reaction; The flow guide assembly 9 includes an upper semicircular plate 91, a second cross bar 92, an upper scraper plate 93, a lower scraper plate 94 and a lower semicircular plate 95. The bottom of the upper semicircular plate 91 is fixedly connected to multiple groups of lower scrapers 94, and the top of the lower semicircular plate 95 is fixedly connected to multiple groups of upper scrapers 93. The upper semicircular plate 91, the upper scraper plate 93, the lower scraper plate 94 and the lower semicircular plate 95 are all slidably connected to the outer wall of the heat transfer tube 10 through the sliding holes opened therein, and the upper semicircular plate 91 and the lower semicircular plate 95 are arranged alternately. The upper semicircular plate 91 is slidably connected to the upper part of the inner wall of the shell 1, and the lower semicircular plate 95 is slidably connected to the lower half of the inner wall of the shell 1. The upper semicircular plate 91, the upper scraper plate 93, the lower scraper plate 94 and the lower semicircular plate 95 are all fixedly connected to the second cross bar 92. The second cross bar 92 is slidably connected to the sliding hole opened in the circular partition 12 on the left side, and the second cross bar 92 is fixedly connected to the spoiler cleaning assembly 4. A sealing ring is installed in the sliding hole where the circular partition 12 on the left side contacts the second cross bar 92; The heating medium enters the housing 1 through the heating medium inlet pipe 5, and the staggered upper semicircular plates 91 and lower semicircular plates 95 guide the heating medium, so that the heating medium heats the heat transfer pipe 10 and is then discharged from the heating medium outlet pipe 7; When not heating, the turbulent cleaning assembly 4 drives the second crossbar 92 to move, and the second crossbar 92 drives the upper semicircular plate 91, the upper scraper 93, the lower scraper 94 and the lower semicircular plate 95 to move, and the upper semicircular plate 91, the upper scraper 93, the lower scraper 94 and the lower semicircular plate 95 move along the outer wall of the heat transfer tube 10, and the upper semicircular plate 91, the upper scraper 93, the lower scraper 94 and the lower semicircular plate 95 clean and scrape away the impurities adhered to the outer wall of the heat transfer tube 10, so as to avoid the impurities affecting the heat transfer of the heat transfer tube 10 and ensure the heat transfer performance of the heat transfer tube 10; The spoiler cleaning assembly 4 includes a cylinder 41, a first cross bar 42, a circular plate 43, an annular scraper 44 and a spoiler assembly. The cylinder 41 is fixedly connected to the first outer cover 2. The output end of the cylinder 41 passes through the first outer cover 2 and is fixedly connected to the circular plate 43. The outer wall of the circular plate 43 is fitted and slidably connected to the inner wall of the first outer cover 2. The circular plate 43 is fixedly connected to multiple groups of first cross bars 42 near the inner wall of the shell 1. The first cross bars 42 are provided with multiple groups of spoiler assemblies at equal intervals. The multiple groups of spoiler assemblies are spirally arranged along the axial direction of the first cross bars 42. The annular scraper 44 is fitted and slidably connected to the inner wall of the heat transfer tube 10. The annular scrapers 44 are arranged at equal intervals and are fixedly connected to the spoiler assembly. The circular plate 43 is fixedly connected to the second cross bar 92; The spoiler assembly includes a plurality of groups of oblique spoilers 45, the outer wall of the first cross bar 42 is fixedly connected with oblique spoilers 45 at equal intervals along the circumferential direction, and the annular scraper 44 is fixedly connected to the oblique spoilers 45; The spacing between adjacent annular scrapers 44 is greater than the spacing between adjacent spoiler components, the spacing between the upper semicircular plate 91 and the lower semicircular plate 95 is the same as the spacing between adjacent annular scrapers 44, and the spacing between adjacent annular scrapers 44 is the stroke of the cylinder 41.
[0034] A sealing ring is provided at the contact portion between the circular plate 43 and the first outer cover 2 for sealing; During heating, the material flows in the heat transfer tube 10, and the oblique spoiler 45 of the spoiler assembly improves the material disturbance. Multiple groups of spoiler assemblies are spirally arranged along the axial direction of the first cross bar 42 to achieve the staggered arrangement of the oblique spoiler 45 of adjacent spoiler assemblies, which further improves the spoiler effect, is conducive to the full mixing of the material in the heat transfer tube 10, is conducive to efficient reaction, and can reduce the adhesion and clogging of high-viscosity materials; When not heating, the cylinder 41 drives the circular plate 43 to move, the circular plate 43 drives the first cross bar 42 to move, the first cross bar 42 drives the annular scraper 44 to move, the annular scraper 44 moves in the heat transfer tube 10, the annular scraper 44 can scrape off the material adhered to the inner wall of the heat transfer tube 10, and further scrape off the material adhered to the inner wall of the heat transfer tube 10. The movement of the circular plate 43 drives the guide component 9 to move, and the guide component 9 scrapes off the impurities adhered to the outer wall of the heat transfer tube 10, so as to avoid the impurities affecting the heat transfer of the heat transfer tube 10 and ensure the heat transfer performance of the heat transfer tube 10.
[0035] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.
Claims
1. A method for producing sulfadimethoxine sodium, characterized in that: The method comprises the following steps: Step 1: p-aminobenzenesulfonamide reacts with acetic anhydride in the presence of a catalyst at a temperature of 50-60° C. for 1-3 hours to generate acetylsulfonamide; Step 2: adding acetylsulfonamide to chloroform, and then contacting with halogen to react under the action of light or an initiator, the reaction temperature is 30-60° C., the time is 2-6 hours, and p-halogenated acetylsulfonamide is generated; Step 3: adding p-haloacetylsulfonamide and 2,4-dimethylpyrimidine to an organic solvent, and then adding an alkaline substance, and carrying out a condensation reaction under alkaline conditions at a reaction temperature of 80-120° C. for 4-8 hours to obtain a condensation product; Step 4: adding an alkaline substance to the condensation product, hydrolyzing the acetyl group in the condensation product to regenerate the amino group, then mixing the sulfadimethazine with a sodium hydroxide solution, and then entering the microchannel reactor for reaction, wherein the temperature in the microchannel reactor is 78-82° C., the residence time is 20-30 seconds, and the pressure is lower than 2.0 MPa to generate sulfadimethazine sodium; Step 5: The finished product of sulfadimethazine sodium is obtained by crystallization, filtration and drying.
2. The method for producing sulfadimethoxine sodium according to claim 1, wherein The catalyst is pyridine.
3. The method for producing sulfadimethoxine sodium according to claim 1, wherein Halogen is bromine or chlorine.
4. The method for producing sulfadimethoxine sodium according to claim 1, wherein The alkaline substance is one or more of potassium carbonate and sodium carbonate.
5. A microchannel reactor used in the method for producing sulfadimethazine sodium according to any one of claims 1 to 4, wherein the microchannel reactor is the microchannel reactor in step 4, and the microchannel reactor comprises a housing (1), characterized in that: Circular partitions (12) are fixedly connected to both left and right ends of the inner wall of the shell (1), and multiple groups of heat transfer tubes (10) are fixedly connected between the circular partitions (12); The left and right ends of the shell (1) are respectively fixedly connected to a first outer cover (2) and a second outer cover (3); the upper and lower ends of the second outer cover (3) are respectively fixedly connected to a material inlet pipe (6) for feeding and a circular partition plate (12) for discharging; A material partition plate (11) is fixedly connected to the middle end of the inner wall of the second outer cover (3), and the material partition plate (11) is fixedly connected to a circular partition plate (12) near the end of the second outer cover (3); A buffer component (8) for stabilizing flow is fixedly connected to the side wall of the second outer cover (3), and the buffer component (8) is located above the material partition plate (11); The inner wall of the shell (1) is provided with a flow guide component (9) for cleaning the outer wall of the heat transfer tube (10) and guiding the heating medium in an S-shaped trajectory; the flow guide component (9) is fitted and slidably connected to the outer wall of the heat transfer tube (10); The end of the first outer cover (2) is fixedly connected to a flow disturbance cleaning component (4) for driving the flow guide component (9) to move back and forth and for disturbing the inner wall of the heat transfer tube (10) and the material in the heat transfer tube (10); the flow disturbance cleaning component (4) is slidably connected to the inner wall of the heat transfer tube (10); The spoiler cleaning component (4) is fixedly connected to the guide component (9), and the portion of the guide component (9) close to the spoiler cleaning component (4) is slidably connected to a sliding hole formed in the circular partition (12) on the left side; A heating medium inlet pipe (5) for the heating medium to enter is fixedly connected to the top of one end of the shell (1), and a heating medium outlet pipe (7) for the heating medium to flow out is fixedly connected to the bottom of the other end of the shell (1).
6. The microchannel reactor according to claim 2, characterized in that: The buffer assembly (8) comprises a third outer cover (81), a slide rod (82), a spring (83) and a piston (84). The third outer cover (81) is connected to the second outer cover (3) and is fixedly connected. The third outer cover (81) is located above the material partition plate (11). The outer end of the third outer cover (81) is slidably connected to the slide rod (82) through a slide hole. The inner end of the slide rod (82) is fixedly connected to the piston (84). The spring (83) is fixedly connected between the side wall of the piston (84) close to the slide rod (82) and the inner wall of the end of the third outer cover (81) away from the housing (1). The outer wall of the piston (84) is slidably connected to the inner wall of the third outer cover (81).
7. The microchannel reactor according to claim 6, characterized in that: The flow guide assembly (9) comprises an upper semicircular plate (91), a second cross bar (92), an upper scraper (93), a lower scraper (94) and a lower semicircular plate (95); the bottom of the upper semicircular plate (91) is fixedly connected to a plurality of groups of lower scrapers (94); the top of the lower semicircular plate (95) is fixedly connected to a plurality of groups of upper scrapers (93); the upper semicircular plate (91), the upper scraper (93), the lower scraper (94) and the lower semicircular plate (95) are all slidably connected to the outer wall of the heat transfer tube (10) through sliding holes provided therein; and the upper semicircular plate (91) is fixedly connected to the outer wall of the heat transfer tube (10) through sliding holes provided therein. ) and the lower semicircular plates (95) are arranged alternately, the upper semicircular plate (91) is fitted and slidably connected to the upper inner wall of the shell (1), the lower semicircular plate (95) is fitted and slidably connected to the lower half of the inner wall of the shell (1), the upper semicircular plate (91), the upper scraper plate (93), the lower scraper plate (94) and the lower semicircular plate (95) are all fixedly connected to the second cross bar (92), the second cross bar (92) is fitted and slidably connected to the sliding hole opened in the circular partition plate (12) on the left side, and the second cross bar (92) is fixedly connected to the spoiler cleaning component (4).
8. The microchannel reactor according to claim 7, characterized in that: The spoiler cleaning assembly (4) comprises a cylinder (41), a first cross bar (42), a circular plate (43), an annular scraper (44) and a spoiler assembly. The cylinder (41) is fixedly connected to the first outer cover (2). The output end of the cylinder (41) passes through the first outer cover (2) and is fixedly connected to the circular plate (43). The outer wall of the circular plate (43) is fitted and slidably connected to the inner wall of the first outer cover (2). The inner wall of the circular plate (43) close to the shell (1) is fixedly connected to multiple groups of first cross bars (42). Multiple groups of spoiler assemblies are arranged at equal intervals on the first cross bars (42). The multiple groups of spoiler assemblies are spirally arranged along the axial direction of the first cross bars (42). The annular scraper (44) is fitted and slidably connected to the inner wall of the heat transfer tube (10). The annular scrapers (44) are arranged at equal intervals. The annular scrapers (44) are fixedly connected to the spoiler assembly.
9. The microchannel reactor according to claim 8, characterized in that: The circular plate (circular plate (43) is fixedly connected to the second cross bar (92).
10. The microchannel reactor according to claim 1, characterized in that: The spoiler assembly comprises a plurality of groups of oblique spoiler blades (45), the outer wall of the first crossbar (42) is fixedly connected with the oblique spoiler blades (45) at equal intervals along the circumferential direction, and the annular scraper (44) is fixedly connected to the oblique spoiler blades (45).