A refining device and method for a key intermediate diketone of isoxaflutole

Abstract

This invention discloses a purification device and method for the key intermediate diketone of isoxaflutole, belonging to the field of pesticide synthesis technology. It solves the problem that existing condensation reaction solutions are strongly alkaline and at high temperatures, leading to localized overheating that easily causes the decomposition of the imine intermediate or side reactions, reducing the conversion efficiency of subsequent oxidation reactions. The device includes a neutralization reactor and a pre-cooling mechanism. The pre-cooling mechanism includes a coolant guiding component, a feed extension section, and a linkage jacket assembly. The linkage jacket assembly includes a telescopic drive component, a telescopic linkage section, a hollow jacket section, and a variable-range mixing section. In this invention, the telescopic drive component drives the hollow jacket section and the spiral turbulence propeller to rotate through the telescopic linkage section. This allows the variable-range translation seat and the upper driving groove and lower positioning groove of the variable-range extension rod in the variable-range mixing section to adaptively adjust the mixing range under the linkage constraint of the variable-range translation seat and the upper driving groove and lower positioning groove, effectively avoiding the decomposition of the imine intermediate or side reactions caused by localized overheating.

Description

Technical Field

[0001] This invention belongs to the field of pesticide synthesis technology, specifically relating to a purification device and method for a key intermediate of isoxazoline, a diketone. Background Technology

[0002] Isoxaflutole is an important pre- and post-emergence herbicide, belonging to the class of p-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors. It is characterized by its broad spectrum, high efficiency, low toxicity, and environmental friendliness, and is widely used for weed control in fields of crops such as corn and sugarcane. In the synthetic route of isoxaflutole, the diketone compound is a key precursor, and the purity of this intermediate directly affects the yield of the final product, isoxaflutole, and the quality of the technical grade herbicide.

[0003] Currently, the industrial methods for preparing diketone intermediates typically involve acylation or condensation reactions. However, in existing production processes, the reaction system is often quite complex. Under alkaline conditions (sodium tert-butoxide), a condensation reaction occurs with cyclopropyl ketone to generate an imine intermediate (1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propanone-1-one). Subsequently, this imine intermediate needs to undergo an oxidative hydrolysis reaction under acidic conditions to convert it into the target diketone product.

[0004] In the transition from condensation to oxidation, the neutralization process is a crucial step. Existing technologies suffer from insufficient temperature control precision and a high risk of side reactions. Current condensation reaction solutions are strongly alkaline and at high temperatures; if directly transferred to an acidic environment without effective pre-cooling, localized overheating can easily lead to the decomposition of the imine intermediate or other side reactions, reducing the conversion efficiency of the subsequent oxidation reaction. To address these issues, we propose a purification device and method for the key intermediate diketone of isoxazolam. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a purification device and method for the key intermediate diketone of isoxazolidinone. This solves the problem that existing condensation reaction solutions are strongly alkaline and at high temperatures, which can easily lead to local overheating, causing the imine intermediate to decompose or undergo side reactions, thus reducing the conversion efficiency of subsequent oxidation reactions.

[0006] This invention is implemented as follows: a purification apparatus for the key intermediate diketone of isoxaflutole, the purification apparatus for the key intermediate diketone of isoxaflutole comprising: The neutralization reactor is fixedly installed on the equipment support, and the top of the neutralization reactor is equipped with a synthesis feeding pipe, while the bottom is connected to the oxidation reactor through an oxidation guide pipe. A pre-cooling mechanism is installed inside the neutralization reactor and is used to pre-cool the synthesis reaction liquid. The extended flow precooling mechanism includes a coolant guiding component, a feed extended flow section, and a linkage jacket assembly. The linkage jacket assembly is installed inside the neutralization reactor and is used to extend flow precool the synthesis reaction liquid and assist in mixing the synthesis reaction liquid. The linkage jacket assembly includes a telescopic drive component, a telescopic linkage part, a hollow jacket part, and a variable range mixing part. The variable range mixing part is sleeved inside the hollow jacket part. The hollow jacket part is rotatably connected to the neutralization reactor. The hollow jacket part is also connected to the telescopic drive component through the telescopic linkage part.

[0007] Preferably, the telescopic linkage part includes: The linkage gear seat is slidably installed inside the equipment bracket, and one end of the linkage gear seat is fixedly connected to the telescopic end of the telescopic drive component; The linkage gear is embedded in the linkage gear seat and meshes with the linkage gear seat for transmission. The linkage gear is fixedly sleeved on the outer wall of the hollow jacket.

[0008] Preferably, the feed extension section includes a feed extension plate, which is fixedly installed on the inner wall of the neutralization reactor, and a feed extension groove is provided in the feed extension plate. The feed extension section is used to cooperate with the coolant guiding assembly to pre-cool and extend the reaction liquid.

[0009] Preferably, the coolant guiding assembly includes: A coolant injection pipe is fixedly installed on the top of the neutralization reactor; A first spiral precooling pipe connected to the coolant injection pipe is fixedly embedded in the neutralization reactor and is used to work with the feed plate to cool the synthesis reaction liquid. The second spiral precooling tube is fixedly installed on the inner wall of the neutralization reactor. It is used to perform secondary cooling on the pre-treated synthesis reaction liquid and to delay the flow of the synthesis reaction liquid. The coolant discharge seat is fixedly sleeved on the outer wall of the neutralization reactor, and the coolant discharge seat is connected to the second spiral precooling pipe.

[0010] Preferably, the hollow jacket portion includes: A hollow jacketed tube is rotatably installed inside the neutralization reactor, and the bottom of the hollow jacketed tube is fixedly connected to the linkage gear. A U-shaped guide tube is embedded in the hollow jacket tube, with one end of the U-shaped guide tube connected to the coolant injection pipe and the other end connected to the coolant discharge seat. The U-shaped guide tube is rotatably connected to the inner wall of the hollow jacket tube. The spiral turbulence propeller is fixedly sleeved on the top of the hollow jacket tube and is used to spiral turbulence the synthesis reaction liquid and assist in mixing the synthesis reaction liquid.

[0011] Preferably, the variable-range mixing section includes: The lower positioning plate is rotatably sleeved on the outer wall of the hollow jacket tube, and the lower positioning plate is detachably connected to the inner wall of the synthesis reactor. At least one set of lower positioning slots is formed within the lower positioning plate; The upper drive plate is fixedly sleeved on the outer wall of the hollow jacket tube, and at least one set of upper drive grooves are opened in the upper drive plate. The variable range slider is slidably fitted into the upper drive groove and the lower positioning groove.

[0012] A variable-range flow extension section is disposed inside the neutralization reactor, and the variable-range flow extension section is detachably connected to the variable-range slider.

[0013] Preferably, the variable range extension section includes: A flow-extending support bracket is fixedly installed on the variable-range slider. A variable-range translation seat fixedly connected to a flow-extending support frame, the variable-range translation seat being used for the flow-extending mixing of the synthesis reaction liquid; At least one set of variable-range guide channels is formed within the variable-range translation seat; At least one set of variable-range flow extension rods is detachably installed in the flow extension support frame.

[0014] Preferably, the oxidation reactor is fixedly mounted on the equipment support, and an oxidation reaction chamber is provided inside the oxidation reactor. An auxiliary oxidation mechanism is also provided inside the oxidation reaction chamber. The auxiliary oxidation mechanism includes: An auxiliary drive motor is fixedly installed inside the oxidation reaction chamber. An auxiliary drive rod is fixedly connected to the output shaft of the auxiliary drive motor. A heat insulation jacket is fixedly connected to the end of the auxiliary drive rod away from the auxiliary drive motor. The heat insulation jacket is rotatably connected to the inner wall of the oxidation reaction vessel. At least one set of auxiliary stirring paddles is fixedly installed on the outer wall of the insulation jacket; The heating guide section includes a heating guide pipe and a heating liquid discharge pipe. The heating guide pipe is fixedly installed inside the oxidation reactor, and the heat preservation jacket is rotatably sleeved on the outside of the heating guide pipe. One end of the heating guide pipe is connected to the heating liquid discharge pipe. A nitrogen supply unit is provided inside the oxidation reactor, and the nitrogen supply unit includes a nitrogen injection tank, an annular uniform distribution pipe and at least one set of nitrogen injection pipes. The annular uniform distribution pipe and the nitrogen injection pipes are respectively fixedly installed inside the oxidation reaction chamber. The annular uniform distribution pipe and the nitrogen injection pipes are connected to each other, and the annular uniform distribution pipe is connected to the nitrogen injection tank. A splash-proof protection section is installed inside the oxidation reaction chamber and is fixedly connected to the heat insulation jacket. The splash-proof protection section is used to prevent the oxidation reaction liquid from overflowing or being entrained by mist. The integrated condensation cyclone trap, which works in conjunction with the splash protection unit, is located inside the oxidation reaction chamber and is connected to the auxiliary drive rod.

[0015] Preferably, the splash-proof protection includes: A splash-proof protective plate is fixedly sleeved on the top of the insulation jacket, and at least one set of defoaming grooves is provided inside the splash-proof protective plate; At least one set of demister cones is fixedly installed at the bottom of the splash-proof protective plate; At least one set of rotating discrete hammers are rotatably mounted on the side wall of the splash-proof protective disk, and discrete friction strips are fixedly mounted on the side wall of the rotating discrete hammers.

[0016] Preferably, the integrated condensation cyclone trap includes: A rotary sealing seat is fixedly sleeved on the outer wall of the auxiliary drive rod, and a drive gear is fixedly installed at the bottom of the rotary sealing seat; At least one set of negative pressure vortex seats are rotatably installed inside the solid-liquid separation condenser, and negative pressure spiral grooves are embedded in the negative pressure vortex seats. The solid-liquid separation condenser is fixedly installed on the top of the oxidation reaction chamber. At least one set of solid-liquid separation chambers are embedded in the solid-liquid separation condenser. An organic phase reflux pipe is fixedly connected to one side of the solid-liquid separation chamber, and the end of the organic phase reflux pipe away from the solid-liquid separation chamber extends into the oxidation reaction chamber. At least one set of driven gears is fixedly installed at the bottom of the negative pressure vortex seat, and the driven gears mesh with the driving gears for transmission.

[0017] On the other hand, the present invention also provides a method for purifying a key intermediate diketone of isoxazolidinone, wherein the method for purifying the key intermediate diketone of isoxazolidinone specifically includes: S10, under nitrogen protection and alkaline conditions, 3-methylthio-4-cyanotrifluorotoluene, methyl tert-butyl ether, and sodium tert-butoxide were added to a synthesis reactor. The temperature was raised to 40°C, and cyclopropyl ketone was added dropwise to the synthesis reactor. The temperature was controlled below 55°C and the reaction was stirred. The addition was completed in 1 hour, and the temperature was maintained for another 1 hour. The methyl tert-butyl ether was removed under normal pressure to obtain the synthesis reaction solution. S20, add methyl tert-butyl ether and water to the neutralization reactor, freeze and cool to below 20°C, transfer the synthesis reaction solution to the neutralization reactor, control the temperature within 30°C, add 60% concentrated sulfuric acid dropwise, adjust the pH to 3, neutralize the synthesis reaction solution through the neutralization reactor, stir for 20 minutes and retest, let stand and separate into layers, wastewater is treated, continue to add 60% concentrated sulfuric acid to the reactor, and then transfer to the oxidation reactor; S30, the oxidation reactor is heated to 53-55℃ under micro-reflux and reacted for 4 hours. After passing the test, the temperature is lowered to 45℃ to obtain the oxidation reaction solution. S40, the oxidation reaction solution was allowed to stand and separate into layers to remove acidic wastewater. It was then washed with water and separated into layers twice. The final water wash was adjusted to pH=7 with a saturated sodium bicarbonate solution. The mixture was stirred for 20 minutes and allowed to stand and separate into layers. The temperature of the above operations was controlled at around 45℃. The upper organic phase in the neutralized reaction solution was transferred to a desolventizing vessel. Methyl tert-butyl ether was first distilled under normal pressure and then under reduced pressure. To ensure that the water in the vessel was clean, a small amount of toluene was added to remove water from the system under reduced pressure until no fraction was distilled off. The temperature was lowered to 70℃, and acetic anhydride was pumped into the desolventizing vessel to dissolve the ether, thus obtaining 1-cyclopropyl-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propane-1,3-dione.

[0018] Compared with the prior art, the embodiments of this application have the following main advantages: In this embodiment of the invention, the synergistic effect of layer-by-layer flow extension, gradient precooling, and dynamic mixing of the synthesis reaction liquid is achieved by integrating a flow extension and precooling mechanism in the neutralization reactor: after the synthesis reaction liquid is guided by the feed flow extension groove of the feed flow extension plate, it is initially cooled by contact with the first spiral precooling tube, and then undergoes secondary cooling under the delaying and guiding effect of the second spiral precooling tube. At the same time, the telescopic drive component drives the hollow jacket and the spiral turbulence propeller to rotate through the telescopic linkage part, so that the mixing range is adaptively adjusted under the linkage constraint of the upper drive groove and lower positioning groove of the variable range translation seat and the variable range flow extension rod in the variable range mixing part. Thus, while ensuring that the reaction liquid is fully precooled to below 20°C, efficient heat exchange and uniform mixing between the cooling medium and the reaction liquid are achieved, effectively avoiding the decomposition of imine intermediates or side reactions caused by local overheating. In addition, the auxiliary oxidation mechanism installed inside the oxidation reactor ensures the stable progress of the micro-reflux oxidation reaction and prevents flooding and mist entrainment through precise temperature control of the insulation jacket and heating guide section, uniform gas distribution of the nitrogen supply section, and coordinated collection of the splash protection section and the integrated condenser cyclone collector. Ultimately, it significantly improves the oxidation conversion efficiency of 1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propanone-1-one to the target diketone, reduces production energy consumption and material loss, and improves product purity and process safety.

[0019] In this embodiment of the invention, the feed extension channel on the feed extension plate extends the flow of the synthesis reaction liquid, greatly increasing the heat exchange area. At the same time, the feed extension plate, together with the first spiral precooling tube and the second spiral precooling tube, forms a stepped counter-current cooling channel, realizing precise temperature control of the reaction liquid from the initial heat exchange to the secondary deep cooling. The synergistic cooperation of the feed extension plate, the first spiral precooling tube and the second spiral precooling tube not only ensures that the reaction liquid is rapidly and uniformly cooled to below 20°C during the extension process, effectively avoiding the risk of accidental precipitation caused by overcooling, but also ensures the stability of the system temperature field by delaying the flow.

[0020] In this embodiment of the invention, the hollow jacket consists of a hollow jacket tube, a U-shaped guide tube, and a spiral turbulence propeller. The U-shaped guide tube forms an independent closed-loop cooling channel inside the hollow jacket tube, which, together with the external coolant guiding assembly, achieves a highly efficient heat exchange mode of internal cooling and external guidance. At the same time, the spiral turbulence propeller driven by the linkage gear rotates synchronously with the hollow jacket tube, forcibly spiral-cutting and radially ejecting the reaction liquid, forcing the liquid flow to form a complex turbulent path inside the vessel. This not only significantly improves the cooling rate by increasing the heat exchange area and turbulence intensity, but also effectively destroys the liquid film boundary layer by utilizing mechanical shear force, fundamentally preventing crystallization and pipeline blockage caused by local supercooling under low-temperature conditions.

[0021] In this embodiment of the invention, a variable-range mixing section is provided. When the pre-cooled synthesis reaction liquid falls into the bottom of the reactor, it is blocked by the wedge-shaped surface on the variable-range translation seat and guided by the variable-range guide groove, forcing it to undergo multi-directional splitting and merging. Combined with the shearing action of the variable-range extension rod, the synthesis reaction liquid is controlled from violent turbulent mixing to stable extension delivery, effectively avoiding side reactions caused by sudden changes in local pH value.

[0022] In this embodiment of the invention, the auxiliary oxidation mechanism utilizes a closed-loop heat medium circulation formed by a heating guide pipe in conjunction with an insulation jacket to achieve precise constant temperature control of the reaction system, avoiding side reactions caused by local overheating. Simultaneously, multi-point uniform bubbling of the nitrogen supply unit creates an oxygen-free inert protective environment and utilizes nitrogen as a stripping medium to efficiently remove the water generated in the reaction, promoting the forward reaction. Furthermore, a splash guard is fixedly connected to the top of the insulation jacket to intercept large droplets generated by vigorous stirring. The integrated condenser-cyclone collector, linked to an auxiliary drive rod via a transmission mechanism, centrifugally separates and condenses the rising gas flow while rotating with the shaft, effectively suppressing mist entrainment and boiling over during vacuum distillation, thereby significantly improving the safety, conversion rate, and product purity of the oxidation reaction. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the purification equipment for the key intermediate diketone of isoxazolidin provided by the present invention.

[0024] Figure 2 This is a three-dimensional structural schematic diagram of the purification equipment for the key intermediate diketone of isoxazolidin provided by the present invention.

[0025] Figure 3 This is a side view of the purification equipment for the key intermediate diketone of isoxazolidin provided by the present invention.

[0026] Figure 4 yes Figure 3 A sectional view along the AA direction.

[0027] Figure 5 This is a schematic diagram of the extended flow precooling mechanism provided by the present invention.

[0028] Figure 6 This is a three-dimensional structural schematic diagram of the extended flow precooling mechanism provided by the present invention.

[0029] Figure 7 This is a top view of the extended flow precooling mechanism provided by the present invention.

[0030] Figure 8 yes Figure 7 BB-direction sectional view.

[0031] Figure 9 This is a schematic diagram of the structure of the feed extension section provided by the present invention.

[0032] Figure 10 This is an isometric view of the feed extension section provided by the present invention.

[0033] Figure 11 This is a top view of the feed extension section provided by the present invention.

[0034] Figure 12 This is a schematic diagram of the structure of the variable range mixing section provided by the present invention.

[0035] Figure 13 This is a front view of the variable range mixing section provided by the present invention.

[0036] Figure 14 This is a top view of the variable range mixing section provided by the present invention.

[0037] Figure 15 This is a schematic diagram of the structure of the oxidation reactor provided by the present invention.

[0038] Figure 16 This is a front view of the oxidation reactor provided by the present invention.

[0039] Figure 17 yes Figure 16 CC-direction sectional view.

[0040] Figure 18 This is a schematic diagram of the auxiliary oxidation mechanism provided by the present invention.

[0041] Figure 19 This is a front view of the auxiliary oxidation mechanism provided by the present invention.

[0042] Figure 20 yes Figure 19 DD section view.

[0043] Figure 21 This is a schematic diagram of the splash-proof protection part provided by the present invention.

[0044] Figure 22 This is a bottom view of the splash-proof protection part provided by the present invention.

[0045] Figure 23 This is a schematic diagram of the integrated condenser cyclone trap provided by the present invention.

[0046] In the diagram: 1-Equipment support, 2-Neutralization reactor, 21-Synthesis feed pipe, 22-Oxidation reactor, 221-Oxidation reaction chamber, 222-Replenishment port, 223-Oxidation liquid outlet, 23-Feeding extension section, 231-Feeding extension plate, 232-Feeding extension groove, 3-Linkage jacket assembly, 31-Telescopic drive component, 32-Telescopic linkage section, 321-Linkage gear seat, 322-Linkage gear, 33-Hollow jacket section. 331-Hollow jacketed tube, 332-U-shaped guide tube, 333-Helical turbulence propeller, 4-Coolant guide assembly, 41-Coolant injection pipe, 42-First spiral precooling tube, 43-Second spiral precooling tube, 44-Coolant discharge seat, 5-Variable range mixing section, 51-Lower positioning plate, 52-Upper drive plate, 53-Lower positioning groove, 54-Upper drive groove, 55-Variable range slider, 56-Variable range flow extension section, 561-Flow extension bearing Bracket, 562-Variable Range Translation Seat, 563-Variable Range Guide Channel, 564-Variable Range Flow Extension Rod, 6-Auxiliary Oxidation Mechanism, 61-Auxiliary Drive Motor, 62-Auxiliary Drive Rod, 63-Nitrogen Supply Unit, 631-Nitrogen Injection Tank, 632-Annular Distribution Pipe, 633-Nitrogen Injection Pipe, 64-Heating Guide Unit, 641-Heating Guide Pipe, 642-Heating Liquid Discharge Pipe, 65-Splash Protection Unit, 651-Splash Protection Protective plate, 652- Demister tank, 653- Demister cone, 654- Rotary discrete hammer, 655- Discrete friction strip, 66- Condensation cyclone integrated trap, 661- Driving gear, 662- Driven gear, 663- Negative pressure cyclone seat, 664- Negative pressure spiral groove, 665- Solid-liquid separation condenser, 666- Solid-liquid separation chamber, 667- Organic phase reflux pipe, 67- Auxiliary stirring paddle, 68- Insulation jacket, 69- Rotary sealing seat. Detailed Implementation

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] The existing condensation reaction solution is strongly alkaline and at a high temperature. If it is directly transferred to an acidic environment without effective pre-cooling, local overheating can easily lead to the decomposition of the imine intermediate or side reactions, reducing the conversion efficiency of subsequent oxidation reactions. To address the above problems, we propose a purification device and method for the key intermediate diketone of isoxazolam. In short, the device consists of a neutralization reactor 2 and a pre-cooling mechanism. The pre-cooling mechanism includes a coolant guiding component 4, a feed pre-cooling section 23, and a linkage jacket assembly 3. The linkage jacket assembly 3 includes a telescopic drive component 31, a telescopic linkage section 32, a hollow jacket section 33, and a variable-range mixing section 5. During operation, the synthesis reaction liquid after condensation reaction enters the neutralization reaction vessel 2 through the synthesis feed pipe 21. Then, the telescopic drive component 31 is activated, which drives the telescopic linkage part 32 to move. This causes the telescopic linkage part 32 to rotate the hollow jacket part 33, which in turn drives the variable range mixing part 5 to move. Through the coordinated action of the time-varying range mixing part 5, the coolant guide component 4, and the feed extension part 23, the extension and pre-cooling of the synthesis reaction liquid is achieved. This ensures effective pre-cooling of the synthesis reaction liquid, avoids local overheating that could lead to the decomposition of the imine intermediate or side reactions, and improves the oxidation reaction conversion efficiency of the key intermediate diketone of isoxazolidinone. In this embodiment of the invention, the integrated pre-cooling mechanism within the neutralization reactor 2 achieves the synergistic effect of layer-by-layer pre-cooling, gradient pre-cooling, and dynamic mixing of the synthetic reaction liquid. After being guided by the feed pre-cooling groove 232 of the feed pre-cooling plate 231, the synthetic reaction liquid undergoes initial contact cooling with the first spiral pre-cooling tube 42. Subsequently, it completes secondary cooling under the delayed guiding effect of the second spiral pre-cooling tube 43. Simultaneously, the telescopic drive 31 drives the hollow jacket 33 and the spiral turbulence propeller 333 to rotate through the telescopic linkage part 32. This causes the mixing range to be adaptively adjusted under the linkage constraint of the upper drive groove 54 and lower positioning groove 53 of the variable range translation seat 562 and the variable range pre-cooling rod 564 in the variable range mixing part 5. Thus, while ensuring that the reaction liquid is fully pre-cooled to below 20°C, efficient heat exchange and uniform mixing between the cooling medium and the reaction liquid are achieved, effectively avoiding the decomposition of imine intermediates or side reactions caused by local overheating. Furthermore, the auxiliary oxidation mechanism 6 installed inside the oxidation reactor 22 ensures the stable progress of the micro-reflux oxidation reaction and prevents flooding and mist entrainment through precise temperature control by the insulation jacket 68 and the heating guide section 64, uniform gas distribution by the nitrogen supply section 63, and coordinated collection by the anti-splash protection section 65 and the condenser cyclone collector 66. Ultimately, it significantly improves the oxidation conversion efficiency of 1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)acetone-1-one to the target diketone, reduces production energy consumption and material loss, and improves product purity and process safety.

[0050] This invention provides a purification apparatus for the key intermediate diketone of isoxazolidin, such as... Figures 1-4As shown, the purification equipment for the key intermediate diketone of isoxazolidin specifically includes: The neutralization reactor 2 is fixedly installed on the equipment support 1, and the top of the neutralization reactor 2 is provided with a synthesis feeding pipe 21, and the bottom is connected to the oxidation reactor 22 through an oxidation guide pipe; wherein, the neutralization reactor 2 can be a hollow cylindrical tank or cylindrical structure, and the neutralization reactor 2 is fixedly installed on the equipment support 1 by welding or snap-fit.

[0051] The end of the synthesis feed pipe 21, away from the neutralization reactor 2, is connected to the synthesis reactor. A condensation reaction takes place within the synthesis reactor. Specifically, under nitrogen protection and alkaline conditions, 3-methylthio-4-cyanotrifluorotoluene, methyl tert-butyl ether, and sodium tert-butoxide are added to the synthesis reactor. The temperature is raised to 40°C, and cyclopropyl ketone is added dropwise. The reaction is carried out with stirring at a temperature below 55°C for 1 hour. After the addition is completed, the temperature is maintained for another 1 hour. The methyl tert-butyl ether is then removed under normal pressure to obtain the synthesis reaction solution. The condensation reaction formula for the synthesis of 1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propanone-1-one is as follows: A pre-cooling mechanism is installed inside the neutralization reactor 2 to pre-cool the synthesis reaction liquid. Among them, such as Figures 5-8 As shown, the extended flow precooling mechanism includes a coolant guiding component 4, a feed extended flow section 23, and a linkage jacket component 3. The linkage jacket component 3 is disposed in the neutralization reaction vessel 2. The linkage jacket component 3 is used to extend flow precool the synthesis reaction liquid and assist in mixing the synthesis reaction liquid. The linkage jacket assembly 3 includes a telescopic drive component 31, a telescopic linkage part 32, a hollow jacket part 33, and a variable range mixing part 5. The variable range mixing part 5 is sleeved inside the hollow jacket part 33. The hollow jacket part 33 is rotatably connected to the neutralization reactor 2. The hollow jacket part 33 is also connected to the telescopic drive component 31 through the telescopic linkage part 32.

[0052] In this embodiment, the telescopic drive component 31 can be a hydraulic cylinder, a pneumatic cylinder, or an electric push rod. The telescopic drive component 31 is fixedly installed in the equipment bracket 1 by means of fastening bolts or snap-fit.

[0053] In this embodiment of the invention, the integrated pre-cooling mechanism within the neutralization reactor 2 achieves the synergistic effect of layer-by-layer pre-cooling, gradient pre-cooling, and dynamic mixing of the synthetic reaction liquid. After being guided by the feed pre-cooling groove 232 of the feed pre-cooling plate 231, the synthetic reaction liquid undergoes initial contact cooling with the first spiral pre-cooling tube 42. Subsequently, it completes secondary cooling under the delayed guiding effect of the second spiral pre-cooling tube 43. Simultaneously, the telescopic drive 31 drives the hollow jacket 33 and the spiral turbulence propeller 333 to rotate through the telescopic linkage part 32. This causes the mixing range to be adaptively adjusted under the linkage constraint of the upper drive groove 54 and lower positioning groove 53 of the variable range translation seat 562 and the variable range pre-cooling rod 564 in the variable range mixing part 5. Thus, while ensuring that the reaction liquid is fully pre-cooled to below 20°C, efficient heat exchange and uniform mixing between the cooling medium and the reaction liquid are achieved, effectively avoiding the decomposition of imine intermediates or side reactions caused by local overheating. Furthermore, the auxiliary oxidation mechanism 6 installed inside the oxidation reactor 22 ensures the stable progress of the micro-reflux oxidation reaction and prevents flooding and mist entrainment through precise temperature control by the insulation jacket 68 and the heating guide section 64, uniform gas distribution by the nitrogen supply section 63, and coordinated collection by the anti-splash protection section 65 and the condenser cyclone collector 66. Ultimately, it significantly improves the oxidation conversion efficiency of 1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)acetone-1-one to the target diketone, reduces production energy consumption and material loss, and improves product purity and process safety.

[0054] In a further preferred embodiment of the present invention, such as Figures 1-2 As shown, the telescopic linkage part 32 includes: The linkage gear seat 321 is slidably installed in the equipment bracket 1, and one end of the linkage gear seat 321 is fixedly connected to the telescopic end of the telescopic drive member 31. The linkage gear seat 321 is slidably connected to the equipment bracket 1 through a slide rail or slide groove, while one side of the linkage gear seat 321 is fixedly connected to the telescopic end of the telescopic drive member 31 by a buckle or bolt. The linkage gear 322 is embedded in the linkage gear seat 321, and the linkage gear 322 meshes and drives the linkage gear seat 321. The linkage gear 322 is fixedly sleeved on the outer wall of the hollow jacket part 33.

[0055] In this embodiment, the linkage gear 322 is a one-third or one-quarter incomplete gear, and the linkage gear 322 is riveted or inserted into the outer wall of the hollow jacket tube 331.

[0056] In a further preferred embodiment of the present invention, such as Figures 9-11As shown, the feed extension section 23 includes a feed extension plate 231, which is fixedly installed on the inner wall of the neutralization reactor 2. A feed extension groove 232 is provided in the feed extension plate 231. The feed extension section 23 is used to cooperate with the coolant guiding assembly 4 to pre-cool and extend the reaction liquid. It should be noted that the feed extension plate 231 is arranged in an inclined or spiral shape, and a hollow feed extension groove 232 is opened inside it; the surface of the feed extension groove 232 is provided with at least one set of overflow weirs distributed along the flow direction, which are used to receive and spread the synthesis reaction liquid from the synthesis feed pipe 21 to form a thin liquid film to achieve initial heat exchange and extension. The number of feed extension plates 231 can be 3-8 sets, and one end of the feed extension plate 231 is fixedly installed in the inner wall of the neutralization reactor 2 by plugging or welding.

[0057] The coolant guiding assembly 4 includes: The coolant injection pipe 41 is fixedly installed on the top of the neutralization reactor 2 and is used to connect to the low-temperature cooling medium. In this embodiment, the low-temperature cooling medium includes, but is not limited to, frozen brine, ethylene glycol aqueous solution, and low-temperature methanol. One end of the coolant injection pipe 41 is connected to the cooling medium source through a water pump. A first spiral precooling tube 42, which is connected to the coolant injection pipe 41, is fixedly embedded in the neutralization reactor 2. It is used to work with the feed extension plate 231 to cool the synthesis reaction liquid. The first spiral precooling tube 42 has a spiral structure with 3-8 spiral turns. The bottom of the first spiral precooling tube 42 is connected to the top of the second spiral precooling tube 43. The first spiral precooling tube 42 is embedded between the inner wall and the outer wall of the neutralization reactor 2 and does not directly contact the synthesis reaction liquid, thereby avoiding the phenomenon of precipitation caused by overcooling of the synthesis reaction liquid. The second spiral precooling tube 43 is fixedly installed on the inner wall of the neutralization reactor 2. It is used to perform secondary cooling on the pre-treated synthesis reaction liquid and to delay the flow of the synthesis reaction liquid. The second spiral precooling tube 43 has a spiral structure that is wider at the top and narrower at the bottom. The second spiral precooling tube 43 is used to perform secondary spiral flow and deep cooling on the synthesis reaction liquid that has been pre-cooled by the first spiral precooling tube 42. The coolant discharge seat 44 is fixedly sleeved on the outer wall of the neutralization reactor 2, and the coolant discharge seat 44 is connected to the second spiral precooling pipe 43.

[0058] In this embodiment of the invention, the feed extension groove 232 provided on the feed extension plate 231 is used to extend the flow of the synthesis reaction liquid, which greatly increases the heat exchange area. At the same time, the feed extension plate 231, together with the first spiral precooling tube 42 and the second spiral precooling tube 43, forms a stepped counter-current cooling channel, which realizes precise temperature control of the reaction liquid from the initial heat exchange to the secondary deep cooling. The feed extension plate 231, the first spiral precooling tube 42 and the second spiral precooling tube 43 work together to ensure that the reaction liquid is rapidly and uniformly cooled to below 20°C during the extension process, effectively avoiding the risk of accidental precipitation caused by overcooling, and also ensuring the stability of the system temperature field by delaying the flow.

[0059] In a further preferred embodiment of the present invention, such as Figures 5-8 As shown, the hollow jacket portion 33 includes: A hollow jacketed tube 331 is rotatably installed inside the neutralization reactor 2, and the bottom of the hollow jacketed tube 331 is fixedly connected to the linkage gear 322. The hollow jacketed tube 331 can be a hollow cylinder or tube structure. The hollow jacketed tube 331 is rotatably connected to the neutralization reactor 2 through a bearing. The lower outer wall of the hollow jacketed tube 331 is circumferentially fixed to the linkage gear 322 through a rigid connector or spline structure, so as to achieve synchronous rotation under the drive of the telescopic linkage part 32. A U-shaped guide tube 332 is embedded in the hollow jacket tube 331, with one end of the U-shaped guide tube 332 connected to the coolant injection pipe 41 and the other end connected to the coolant discharge seat 44. The U-shaped guide tube 332 is rotatably connected to the inner wall of the hollow jacket tube 331. The U-shaped guide tube 332 can be a round tube or a spiral tube structure. One end of the U-shaped guide tube 332 is connected to the coolant injection pipe 41 through a sealing flange. The spiral turbulence propeller 333 is fixedly sleeved on the top of the hollow jacket tube 331. It is used to spiral turbulence the synthesis reaction liquid and assist in mixing the synthesis reaction liquid. When the equipment is working, as the hollow jacket tube 331 rotates, the spiral turbulence propeller 333 performs forced spiral cutting and radial ejection on the falling synthesis reaction liquid, forcing the liquid flow to impact the first spiral precooling tube 42 or the feed extension plate 231, thereby achieving the triple effect of heat exchange, turbulence and mixing at the same time, effectively preventing pipeline blockage caused by local supercooling crystallization.

[0060] In this embodiment of the invention, the hollow jacket 33 is composed of a hollow jacket tube 331, a U-shaped guide tube 332, and a spiral turbulence propeller 333. The U-shaped guide tube 332 forms an independent closed-loop cooling channel inside the hollow jacket tube 331, which, together with the external coolant guide assembly 4, achieves a highly efficient heat exchange mode of internal cooling and external guidance. At the same time, the spiral turbulence propeller 333, driven by the linkage gear 322, rotates synchronously with the hollow jacket tube 331, forcibly spiral-cutting and radially ejecting the reaction liquid, forcing the liquid flow to form a complex turbulent path in the reactor. This not only significantly improves the cooling rate by increasing the heat exchange area and turbulence intensity, but also effectively destroys the liquid film boundary layer by using mechanical shear force, fundamentally preventing crystallization and pipeline blockage caused by local overcooling under low-temperature conditions.

[0061] In a further preferred embodiment of the present invention, such as Figures 12-14 As shown, the variable range mixing unit 5 includes: The lower positioning plate 51 is rotatably sleeved on the outer wall of the hollow jacket tube 331, and the lower positioning plate 51 is detachably connected to the inner wall of the synthesis reactor. At least one set of lower positioning grooves 53 are formed within the lower positioning disk 51; The upper drive disk 52 is fixedly sleeved on the outer wall of the hollow jacket tube 331, and at least one set of upper drive grooves 54 are formed inside the upper drive disk 52. The lower positioning disk 51 is rotatably sleeved on the outer wall of the hollow jacket tube 331 through a bearing or spline structure, and its outer edge is detachably connected to the inner wall of the neutralization reactor 2 through fasteners or snap-fit ​​structures. At least one set of radially distributed lower positioning grooves 53 are formed on the upper surface of the lower positioning disk 51. Correspondingly, the upper drive disk 52 is fixedly sleeved and welded to the outer wall of the hollow jacket tube 331, and at least one set of spiral or involute distributed upper drive grooves 54 are formed on the lower surface of the upper drive disk 52. The number of upper drive grooves 54 and lower positioning grooves 53 are the same. The variable range slider 55 is slidably embedded in the upper drive groove 54 and the lower positioning groove 53. The variable range slider 55 is slidably embedded in the intersection area of ​​the upper drive groove 54 and the lower positioning groove 53, so that when the upper drive disk 52 and the lower positioning disk 51 rotate relative to each other, it can perform radial displacement along a predetermined trajectory. A variable-range flow extension section 56 is disposed inside the neutralization reactor 2, and the variable-range flow extension section 56 is detachably connected to the variable-range slider 55.

[0062] In this embodiment, the variable range extension section 56 includes: The flow-extending support bracket 561 is fixedly installed on the variable-range slider 55; A variable-range translation seat 562 is fixedly connected to the flow support frame 561. The variable-range translation seat 562 is used for the flow mixing of the synthesis reaction liquid. The variable-range translation seat 562 is fixedly connected to the flow support frame 561 by welding or snap-fit. The flow-facing surface of the variable-range translation seat 562 is designed as a wedge-shaped or streamlined structure. At least one set of through variable-range guide grooves 563 are opened inside. The guide grooves are used to guide and change the direction of liquid flow. At least one set of variable range guide channels 563 are formed within the variable range translation seat 562; At least one set of variable range flow extension rods 564 are detachably installed in the flow extension support frame 561. The variable range flow extension rods 564 are fixedly connected to the flow extension support frame 561 by means of snaps or bolts, and the variable range flow extension rods 564 can be arc-shaped, "L"-shaped or "S"-shaped structures.

[0063] During operation, when the pre-cooled synthesis reaction liquid falls into the bottom of the neutralization reactor 2, the hollow jacket tube 331 rotates in both directions, which drives the upper drive disk 52 to rotate. This causes the upper drive disk 52 to drive the upper drive groove 54 to rotate, and the upper drive groove 54 to drive the variable range slider 55 to move along the lower positioning groove 53. As a result, the variable range slider 55 drives the flow extension support 561, the variable range translation seat 562, the variable range guide groove 563, and the variable range flow extension rod 564 to move inside and outside along the inner diameter extension line of the lower positioning disk 51, thereby realizing the flow extension and mixing of the synthesis reaction liquid.

[0064] In this embodiment of the invention, a variable-range mixing section 5 is provided. When the pre-cooled synthesis reaction liquid falls into the bottom of the reactor, it is blocked by the wedge-shaped surface on the variable-range translation seat 562 and guided by the variable-range guide groove 563, forcing it to undergo multi-directional splitting and merging. Combined with the shearing action of the variable-range extension rod 564, the synthesis reaction liquid is controlled from violent turbulent mixing to stable extension delivery, effectively avoiding side reactions caused by sudden changes in local pH value.

[0065] In a further preferred embodiment of the present invention, such as Figures 15-17 As shown, the oxidation reactor 22 is fixedly mounted on the equipment support 1. An oxidation reaction chamber 221 is provided inside the oxidation reactor 22. An oxidation liquid outlet 223 is provided at the bottom of the oxidation reactor 22, and the outlet 223 is connected to the oxidation reaction chamber 221. The outlet 223 can be a conical groove or a frustum-shaped groove structure. At least one set of replenishment ports 222 are provided on the side wall of the oxidation reactor 22. The oxidation reactor 22 is fixedly mounted on the equipment support 1 by a buckle or support arm. An auxiliary oxidation mechanism 6 is provided inside the oxidation reactor 22, and the auxiliary oxidation mechanism 6 is located inside the oxidation reaction chamber 221. Among them, such as Figures 18-20 As shown, the auxiliary oxidation mechanism 6 includes: An auxiliary drive motor 61 is fixedly installed inside the oxidation reaction chamber 221. An auxiliary drive rod 62 is fixedly connected to the output shaft of the auxiliary drive motor 61. An insulation jacket 68 is fixedly connected to the end of the auxiliary drive rod 62 away from the auxiliary drive motor 61. The insulation jacket 68 is rotatably connected to the inner wall of the oxidation reaction vessel 22. The auxiliary drive motor 61 is fixedly installed by welding or riveting. A sealing heat insulation cover is fixedly fitted on the outer wall of the auxiliary drive motor 61. The output shaft of the auxiliary drive motor 61 is fixedly connected to the auxiliary drive rod 62 by interference fit. The other end of the auxiliary drive rod 62 is fixedly connected to the insulation jacket 68 by snap-fit ​​or riveting. At least one set of auxiliary stirring paddles 67 is fixedly installed on the outer wall of the insulation jacket 68. The auxiliary stirring paddles 67 are evenly arranged on the outer wall of the insulation jacket 68 in a circumferential manner, and the number of auxiliary stirring paddles 67 is 3-6 sets. The heating guide section 64 includes a heating guide pipe 641 and a heating liquid discharge pipe 642. The heating guide pipe 641 is fixedly installed inside the oxidation reactor 22, and the insulation jacket 68 is rotatably sleeved on the outside of the heating guide pipe 641. One end of the heating guide pipe 641 is connected to the heating liquid discharge pipe 642. The heating guide pipe 641 is spirally or coiled and fixedly embedded in the insulation jacket 68, without direct contact with the oxidation reaction liquid inside the reactor. One end of the heating guide pipe 641 is connected to the outlet of an external heat source (thermal oil furnace), and the other end is connected to the heating liquid discharge pipe 642, thus forming a closed-loop heat medium circulation circuit. During operation, high-temperature thermal oil flows through the heating guide pipe 641, heating the reaction liquid inside the reactor non-contactly through radiation and convection. Combined with the insulation effect of the insulation jacket 68, the system temperature is stably maintained within the 53-55℃ range required for micro-reflux.

[0066] A nitrogen supply unit 63 is disposed within the oxidation reactor 22. The nitrogen supply unit 63 includes a nitrogen injection tank 631, an annular uniform distribution pipe 632, and at least one set of nitrogen injection pipes 633. The annular uniform distribution pipe 632 and the nitrogen injection pipes 633 are respectively fixedly installed within the oxidation reaction chamber 221, and are interconnected. The annular uniform distribution pipe 632 is connected to the nitrogen injection tank 631. The annular uniform distribution pipe 632 is fixedly embedded in the inner side of the reactor lid or reactor wall, with its inlet end connected to the nitrogen injection tank 631 and its outlet end connected to the radially distributed array of nitrogen injection pipes 633. By providing the nitrogen injection pipes 633, nitrogen can be bubbled into the reaction liquid at multiple points and uniformly, providing both an inert protective atmosphere and serving as a stripping medium to assist in removing the water generated during the reaction.

[0067] A splash protection part 65 is disposed in the oxidation reaction chamber 221 and is fixedly connected to the heat insulation jacket 68. The splash protection part 65 is used to prevent the oxidation reaction liquid from overflowing or being entrained by mist. The condensation cyclone trap 66, which works in conjunction with the splash protection unit 65, is located inside the oxidation reaction chamber 221 and is connected to the auxiliary drive rod 62.

[0068] In this embodiment, the splash protection unit 65 and the condenser-cyclone integrated collector 66 constitute a gas-liquid separation system. The splash protection unit 65 is fixedly connected to the top of the insulation jacket 68 to intercept large droplets generated by vigorous stirring. The condenser-cyclone integrated collector 66 is linked to the auxiliary drive rod 62 via a transmission mechanism, and while rotating with the shaft, it centrifugally separates and condenses the rising airflow, effectively preventing material loss and blockage of the vacuum system.

[0069] In this embodiment of the invention, the auxiliary oxidation mechanism 6 utilizes a closed-loop heat medium circulation formed by the heating guide pipe 641 in conjunction with the insulation jacket 68 to achieve precise constant temperature control of the reaction system, avoiding side reactions caused by local overheating. Simultaneously, through multi-point uniform bubbling of the nitrogen supply unit 63, an oxygen-free inert protective environment is constructed, and nitrogen is used as a stripping medium to efficiently carry out the water generated in the reaction, promoting the forward reaction. In addition, the splash protection unit 65 is fixedly connected to the top of the insulation jacket 68 to intercept large-sized droplets generated by violent stirring. The integrated condenser-cyclone collector 66 is linked to the auxiliary drive rod 62 through a transmission mechanism, and while rotating with the shaft, it centrifugally separates and condenses the rising gas flow, effectively curbing mist entrainment and boiling phenomena during the vacuum distillation process, thereby significantly improving the safety, conversion rate, and product purity of the oxidation reaction.

[0070] In a further preferred embodiment of the present invention, such as Figures 21-22 As shown, the splash-proof protection part 65 includes: A splash-proof protective plate 651 is fixedly sleeved on the top of the insulation jacket 68, and at least one set of defoaming grooves 652 are provided inside the splash-proof protective plate 651. The splash-proof protective plate 651 is fixedly connected to the insulation jacket 68 by plugging or snapping, and the defoaming grooves 652 are evenly arranged in the circumference. The defoaming grooves 652 can be arc-shaped grooves, conical grooves, or rectangular grooves, thereby achieving effective interception of large-diameter droplets. At least one set of demister cones 653 are fixedly installed at the bottom of the splash-proof protection plate 651. The demister cones 653 are fixedly installed in a conical array at the bottom center area of ​​the splash-proof protection plate 651, with their tips facing the reaction liquid surface, to break up large bubbles in the center of the rising airflow and guide them to the edge of the plate. At least one set of rotating discrete hammers 654 are rotatably mounted on the side wall of the splash-proof protective disk 651, and discrete friction strips 655 are fixedly mounted on the side wall of the rotating discrete hammers 654.

[0071] In this embodiment, the rotating discrete hammer 654 is rotatably mounted on the side wall edge of the splash-proof protective disk 651 via a pin or bearing; a wear-resistant discrete friction strip 655 is fixed to the outer edge of the rotating discrete hammer 654. During operation, as the insulation jacket 68 rotates, the rotating discrete hammer 654 is thrown out by centrifugal force and undergoes periodic or non-contact frictional vibration with the inner wall of the vessel, thereby shaking off the liquid film and crystals adhering to the vessel wall and preventing heat transfer deterioration caused by material accumulation.

[0072] In a further preferred embodiment of the present invention, such as Figure 23 As shown, the integrated condensation cyclone trap 66 includes: A rotary sealing seat 69 is fixedly sleeved on the outer wall of the auxiliary drive rod 62, and a drive gear 661 is fixedly installed at the bottom of the rotary sealing seat 69. The rotary sealing seat 69 is rotatably connected to the inner wall of the oxidation reactor 22 by means of bearings or sealing flanges. At least one set of negative pressure cyclone seats 663 are rotatably installed inside a solid-liquid separation condenser 665, and a negative pressure spiral groove 664 is embedded in the negative pressure cyclone seat 663. The solid-liquid separation condenser 665 is fixedly installed on the top of the oxidation reaction chamber 221, and at least one set of solid-liquid separation chambers 666 are embedded in the solid-liquid separation condenser 665. An organic phase reflux pipe 667 is fixedly connected to one side of the solid-liquid separation chamber 666, and the end of the organic phase reflux pipe 667 away from the solid-liquid separation chamber 666 extends... Extending into the oxidation reaction chamber 221, the negative pressure vortex seat 663 is rotatably connected to the solid-liquid separation condenser 665 via a bearing. The negative pressure vortex seat 663 has a hollow conical or frustum-shaped structure. The inner wall of the negative pressure vortex seat 663 is machined with spiral upward or downward negative pressure spiral grooves 664 to induce the airflow to generate high-speed rotational motion. It should be noted that the solid-liquid separation condenser 665 can be a vertical or columnar condenser of the prior art. Its condensation and organic phase separation methods will not be described in detail here. At least one set of driven gears 662 are fixedly installed at the bottom of the negative pressure vortex seat 663, and the driven gears 662 mesh with the driving gear 661 for transmission.

[0073] In this embodiment, during operation, the oxidation reaction liquid enters the oxidation reaction chamber 221, and then the auxiliary drive motor 61 is turned on. The start of the auxiliary drive motor 61 drives the auxiliary drive rod 62 to rotate, which in turn drives the insulation jacket 68 to rotate. The insulation jacket 68 drives the auxiliary stirring paddle 67 to rotate. Simultaneously, the heating guide section 64 and the nitrogen supply section 63 are turned on. Through the multi-point uniform bubbling of the nitrogen supply section 63, an oxygen-free inert protective environment is constructed, and nitrogen is used as a stripping medium to efficiently carry out the water generated in the reaction, promoting the forward reaction. At the same time, the auxiliary drive rod 62 drives the rotating sealing seat 69 and the drive gear 661 to rotate, and so on. The driven gear 662 and the negative pressure vortex seat 663 are driven by gear meshing to rotate at high speed in the solid-liquid separation condenser 665. The rising organic vapor and the entrained tiny droplets are first mechanically intercepted and dispersed by the splash protection part 65, removing most of the large droplets. Then, the remaining liquid-containing gas enters the solid-liquid separation condenser 665 and undergoes strong centrifugal swirling motion under the guidance of the negative pressure spiral groove 664. Under the dual action of centrifugal force and condensation wall, the tiny droplets are captured, aggregated and slide down the wall to the solid-liquid separation chamber 666, and finally return to the oxidation reactor 22 through the organic phase return pipe 667, while the non-condensable gas that has been de-dropped is discharged from the top.

[0074] On the other hand, embodiments of the present invention also provide a method for purifying the key intermediate diketone of isoxazolidinone, wherein the method for purifying the key intermediate diketone of isoxazolidinone specifically includes: S10, under nitrogen protection and alkaline conditions, 3-methylthio-4-cyanotrifluorotoluene, methyl tert-butyl ether, and sodium tert-butoxide were added to a synthesis reactor. The temperature was raised to 40°C, and cyclopropyl ketone was added dropwise to the synthesis reactor. The temperature was controlled below 55°C and the reaction was stirred. The addition was completed in 1 hour, and the temperature was maintained for another 1 hour. The methyl tert-butyl ether was removed under normal pressure to obtain the synthesis reaction solution. S20, add methyl tert-butyl ether and water to neutralization reactor 2, freeze and cool to below 20°C, transfer the synthesis reaction solution to neutralization reactor 2, control the temperature within 30°C, add 60% concentrated sulfuric acid dropwise, adjust pH=3, neutralize the synthesis reaction solution through neutralization reactor 2, stir for 20 minutes and retest, let stand and separate into layers, wastewater go to treatment, continue to add 60% concentrated sulfuric acid to the reactor, and then transfer to oxidation reactor 22; The reaction formula between concentrated sulfuric acid and the synthesis reaction solution (1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)acetone-1-one) in oxidation reactor 22 is as follows: S30, the oxidation reactor 22 is heated to 53-55℃ under micro-reflux and reacted for 4 hours. After passing the test, the temperature is lowered to 45℃ to obtain the oxidation reaction solution. S40, the oxidation reaction solution was allowed to stand and separate into layers to remove acidic wastewater. It was then washed with water and separated into layers twice. The final water wash was performed with a saturated sodium bicarbonate solution to adjust the pH to 7. The mixture was stirred for 20 minutes and allowed to stand for further separation. The temperature was controlled at approximately 45℃. The upper organic phase in the neutralized reaction solution was transferred to a desolventizing vessel. Methyl tert-butyl ether was first distilled under normal pressure, then under reduced pressure. To ensure the cleanliness of the water in the vessel, a small amount of toluene was added to remove water from the system under reduced pressure until no more distillate was produced. The temperature was lowered to 70℃, and acetic anhydride was added to the desolventizing vessel to dissolve the ether, yielding 1-cyclopropyl-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propane-1,3-dione. Ultimately, the conversion rate of 1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propanone-1-one was 97.56%.

[0075] In this embodiment of the invention, the purification method for the key intermediate diketone of isoxazolam involves processes such as condensation reaction, pre-cooling and neutralization, oxidation reaction, washing and layering, and solvent removal and dehydration. This achieves efficient and stable preparation of the diketone intermediate. During the condensation stage, nitrogen protection and precise temperature control effectively suppress raw material decomposition and side reactions, resulting in a conversion rate of over 97.85% for 3-methylthio-4-cyanotrifluorotoluene. In the neutralization stage, a pre-cooling, pre-cooling, gradient cooling, and dynamic mixing strategy is employed. The pre-cooling mechanism pre-cools the high-temperature alkaline synthesis reaction solution to below 20°C before it is transferred to an acidic environment. The synergistic effect of the two-stage spiral pre-cooling tube and the variable-range mixing section 5 ensures that the temperature is consistently controlled below 30°C and the pH is precisely stable at 3 during the addition of 60% concentrated sulfuric acid, thus avoiding localized over-cooling. The heat-induced decomposition of the imine intermediate significantly improved its stability. During the oxidation stage, enhanced mass transfer and temperature control through micro-reflux control (53-55℃) and auxiliary oxidation mechanism 6 resulted in a conversion rate of over 97.56% for 1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propane-1-one to the target diketone. Subsequent processes, including multiple water washing and layering, precise pH adjustment to 7 with a saturated sodium bicarbonate solution, vacuum dehydration with toluene, and dissolution with acetic anhydride, ultimately yielded a high-purity 1-cyclopropyl-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propane-1,3-dione solution. The overall process demonstrated strong continuity, high precision in temperature and acidity control, and low material loss, significantly improving the production efficiency and product quality stability of isoxazolidinone intermediates.

[0076] In summary, this invention provides a purification device and method for the key intermediate diketone of isoxazolidinone. In this embodiment, by integrating a pre-cooling mechanism within the neutralization reactor 2, the synergistic effect of layer-by-layer pre-cooling, gradient pre-cooling, and dynamic mixing of the synthetic reaction liquid is achieved: after the synthetic reaction liquid is guided by the feed pre-cooling groove 232 of the feed pre-cooling plate 231, it undergoes initial contact cooling with the first spiral pre-cooling tube 42, and then completes secondary cooling under the delayed guiding effect of the second spiral pre-cooling tube 43. At the same time, the telescopic drive 31 drives the hollow jacket 33 and the spiral turbulence propeller 333 to rotate through the telescopic linkage part 32, so that the mixing range is adaptively adjusted under the linkage constraint of the upper drive groove 54 and lower positioning groove 53 of the variable range translation seat 562 and the variable range pre-cooling rod 564 in the variable range mixing part 5. Thus, while ensuring that the reaction liquid is fully pre-cooled to below 20°C, efficient heat exchange and uniform mixing between the cooling medium and the reaction liquid are achieved, effectively avoiding the decomposition of the imine intermediate or the occurrence of side reactions due to local overheating. Furthermore, the auxiliary oxidation mechanism 6 installed inside the oxidation reactor 22 ensures the stable progress of the micro-reflux oxidation reaction and prevents flooding and mist entrainment through precise temperature control by the insulation jacket 68 and the heating guide section 64, uniform gas distribution by the nitrogen supply section 63, and coordinated collection by the anti-splash protection section 65 and the condenser cyclone collector 66. Ultimately, it significantly improves the oxidation conversion efficiency of 1-cyclopropyl-3-imino-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)acetone-1-one to the target diketone, reduces production energy consumption and material loss, and improves product purity and process safety.

[0077] It should be noted that, for the sake of simplicity, the foregoing embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0078] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

Claims

1. A purification apparatus for the key intermediate diketone of isoxazolidinone, characterized in that, The device includes: The neutralization reactor is fixedly installed on the equipment support, and the top of the neutralization reactor is equipped with a synthesis feeding pipe, while the bottom is connected to the oxidation reactor through an oxidation guide pipe. A pre-cooling mechanism is installed inside the neutralization reactor and is used to pre-cool the synthesis reaction liquid. The extended flow precooling mechanism includes a coolant guiding component, a feed extended flow section, and a linkage jacket assembly. The linkage jacket assembly is installed inside the neutralization reactor and is used to extend flow precool the synthesis reaction liquid and assist in mixing the synthesis reaction liquid. The linkage jacket assembly includes a telescopic drive component, a telescopic linkage part, a hollow jacket part, and a variable range mixing part. The variable range mixing part is sleeved inside the hollow jacket part. The hollow jacket part is rotatably connected to the neutralization reactor. The hollow jacket part is also connected to the telescopic drive component through the telescopic linkage part.

2. The purification equipment for the key intermediate diketone of isoxazolidin as described in claim 1, characterized in that: The telescopic linkage unit includes: The linkage gear seat is slidably installed inside the equipment bracket, and one end of the linkage gear seat is fixedly connected to the telescopic end of the telescopic drive component; The linkage gear is embedded in the linkage gear seat and meshes with the linkage gear seat for transmission. The linkage gear is fixedly sleeved on the outer wall of the hollow jacket.

3. The purification equipment for the key intermediate diketone of isoxazolidin as described in claim 1, characterized in that: The feed extension section includes a feed extension plate, which is fixedly installed on the inner wall of the neutralization reactor, and a feed extension groove is provided in the feed extension plate. The feed extension section is used to cooperate with the coolant guiding assembly to pre-cool and extend the reaction liquid. The coolant guiding assembly includes: A coolant injection pipe is fixedly installed on the top of the neutralization reactor; A first spiral precooling pipe connected to the coolant injection pipe is fixedly embedded in the neutralization reactor and is used to work with the feed plate to cool the synthesis reaction liquid. The second spiral precooling tube is fixedly installed on the inner wall of the neutralization reactor. It is used to perform secondary cooling on the pre-treated synthesis reaction liquid and to delay the flow of the synthesis reaction liquid. The coolant discharge seat is fixedly sleeved on the outer wall of the neutralization reactor, and the coolant discharge seat is connected to the second spiral precooling pipe.

4. The purification equipment for the key intermediate diketone of isoxazolidin as described in claim 3, characterized in that: The hollow jacket portion includes: A hollow jacketed tube is rotatably installed inside the neutralization reactor, and the bottom of the hollow jacketed tube is fixedly connected to the linkage gear. A U-shaped guide tube is embedded in the hollow jacket tube, with one end of the U-shaped guide tube connected to the coolant injection pipe and the other end connected to the coolant discharge seat. The U-shaped guide tube is rotatably connected to the inner wall of the hollow jacket tube. The spiral turbulence propeller is fixedly sleeved on the top of the hollow jacket tube and is used to spiral turbulence the synthesis reaction liquid and assist in mixing the synthesis reaction liquid.

5. The purification equipment for the key intermediate diketone of isoxazolidin as described in claim 4, characterized in that: The variable-range mixing unit includes: The lower positioning plate is rotatably sleeved on the outer wall of the hollow jacket tube, and the lower positioning plate is detachably connected to the inner wall of the synthesis reactor. At least one set of lower positioning slots is formed within the lower positioning plate; The upper drive disk is fixedly sleeved on the outer wall of the hollow jacket tube, and at least one set of upper drive grooves are opened in the upper drive disk. A variable-range slider is slidably fitted into the upper drive groove and the lower positioning groove; A variable-range flow extension section is disposed inside the neutralization reactor, and the variable-range flow extension section is detachably connected to the variable-range slider.

6. The purification equipment for the key intermediate diketone of isoxazolidin as described in claim 5, characterized in that: The variable-range extension section includes: A flow-extending support bracket is fixedly installed on the variable-range slider. A variable-range translation seat fixedly connected to a flow-extending support frame, the variable-range translation seat being used for the flow-extending mixing of the synthesis reaction liquid; At least one set of variable-range guide channels is formed within the variable-range translation seat; At least one set of variable-range flow extension rods is detachably installed in the flow extension support frame.

7. The purification equipment for the diketone, a key intermediate of isoxazolidin, as described in any one of claims 2-6, is characterized in that: The oxidation reactor is fixedly mounted on the equipment support. An oxidation reaction chamber is provided inside the oxidation reactor, and an auxiliary oxidation mechanism is also provided inside the oxidation reaction chamber. The auxiliary oxidation mechanism includes: An auxiliary drive motor is fixedly installed inside the oxidation reaction chamber. An auxiliary drive rod is fixedly connected to the output shaft of the auxiliary drive motor. A heat insulation jacket is fixedly connected to the end of the auxiliary drive rod away from the auxiliary drive motor. The heat insulation jacket is rotatably connected to the inner wall of the oxidation reaction vessel. At least one set of auxiliary stirring paddles is fixedly installed on the outer wall of the insulation jacket; The heating guide section includes a heating guide pipe and a heating liquid discharge pipe. The heating guide pipe is fixedly installed inside the oxidation reactor, and the heat preservation jacket is rotatably sleeved on the outside of the heating guide pipe. One end of the heating guide pipe is connected to the heating liquid discharge pipe. A nitrogen supply unit is provided inside the oxidation reactor, and the nitrogen supply unit includes a nitrogen injection tank, an annular uniform distribution pipe and at least one set of nitrogen injection pipes. The annular uniform distribution pipe and the nitrogen injection pipes are respectively fixedly installed inside the oxidation reaction chamber. The annular uniform distribution pipe and the nitrogen injection pipes are connected to each other, and the annular uniform distribution pipe is connected to the nitrogen injection tank. A splash-proof protection section is installed inside the oxidation reaction chamber and is fixedly connected to the heat insulation jacket. The splash-proof protection section is used to prevent the oxidation reaction liquid from overflowing or being entrained by mist. The integrated condensation cyclone trap, which works in conjunction with the splash protection unit, is located inside the oxidation reaction chamber and is connected to the auxiliary drive rod.

8. The purification equipment for the key intermediate diketone of isoxazolidin as described in claim 7, characterized in that: The splash protection includes: A splash-proof protective plate is fixedly sleeved on the top of the insulation jacket, and at least one set of defoaming grooves are provided inside the splash-proof protective plate; At least one set of demister cones is fixedly installed at the bottom of the splash-proof protective plate; At least one set of rotating discrete hammers are rotatably mounted on the side wall of the splash-proof protective disk, and discrete friction strips are fixedly mounted on the side wall of the rotating discrete hammers.

9. The purification equipment for the key intermediate diketone of isoxazolidin as described in claim 7, characterized in that: The integrated condenser-cyclone trap includes: A rotary sealing seat is fixedly sleeved on the outer wall of the auxiliary drive rod, and a drive gear is fixedly installed at the bottom of the rotary sealing seat; At least one set of negative pressure vortex seats are rotatably installed inside the solid-liquid separation condenser, and negative pressure spiral grooves are embedded in the negative pressure vortex seats. The solid-liquid separation condenser is fixedly installed on the top of the oxidation reaction chamber. At least one set of solid-liquid separation chambers are embedded in the solid-liquid separation condenser. An organic phase reflux pipe is fixedly connected to one side of the solid-liquid separation chamber, and the end of the organic phase reflux pipe away from the solid-liquid separation chamber extends into the oxidation reaction chamber. At least one set of driven gears is fixedly installed at the bottom of the negative pressure vortex seat, and the driven gears mesh with the driving gears for transmission.

10. The purification apparatus for the isoxazolidin key intermediate diketone according to any one of claims 1-9, and the purification method for the isoxazolidin key intermediate diketone, characterized in that: The purification method for the key intermediate diketone of isoxazolidinone includes: S10, under nitrogen protection and alkaline conditions, 3-methylthio-4-cyanotrifluorotoluene, methyl tert-butyl ether, and sodium tert-butoxide were added to a synthesis reactor. The temperature was raised to 40°C, and cyclopropyl ketone was added dropwise to the synthesis reactor. The temperature was controlled below 55°C and the reaction was stirred. The addition was completed in 1 hour, and the temperature was maintained for another 1 hour. The methyl tert-butyl ether was removed under normal pressure to obtain the synthesis reaction solution. S20, add methyl tert-butyl ether and water to the neutralization reactor, freeze and cool to below 20°C, transfer the synthesis reaction solution to the neutralization reactor, control the temperature within 30°C, add 60% concentrated sulfuric acid dropwise, adjust the pH to 3, neutralize the synthesis reaction solution through the neutralization reactor, stir for 20 minutes and retest, let stand and separate the layers, continue to add 60% concentrated sulfuric acid to the reactor, and then transfer to the oxidation reactor; S30, the oxidation reactor is heated to 53-55℃ under micro-reflux and reacted for 4 hours. After passing the test, the temperature is lowered to 45℃ to obtain the oxidation reaction solution. S40, the oxidation reaction solution was allowed to stand and separate into layers to remove acidic wastewater. The final water wash was performed with a saturated sodium bicarbonate solution to adjust the pH to 7. After stirring for 20 minutes, the solution was allowed to stand and separate into layers. The upper organic phase in the neutralized reaction solution was transferred to a desolvation vessel. Methyl tert-butyl ether was first distilled under normal pressure and then under reduced pressure. Acetic anhydride was then added to the desolvation vessel to dissolve the ether, yielding 1-cyclopropyl-3-(2-(methylthio)-4-(trifluoromethyl)phenyl)propane-1,3-dione.

Images