Preparation equipment and preparation process of p-fluorobenzoyl chloride

Abstract

The application relates to a preparation device for p-fluorobenzoyl chloride, which comprises a reaction kettle, a cooling device connected with the reaction kettle and a vacuumizing device, a feeding port and a discharging port are arranged at the upper and lower ends of the reaction kettle respectively, a lifting partition device and a stirring device are arranged in the reaction kettle, the lifting partition device comprises an upper partition plate, a lower partition plate and a driving device for driving the upper partition plate to lift, a sealing rubber sleeve is arranged at the side edge of the upper partition plate, the upper partition plate and the lower partition plate separately partition the inner cavity of the reaction kettle, and the inner cavity of the reaction kettle is sequentially formed into a reaction cavity, a filtering cavity and a distillation cavity from top to bottom, so that different process treatments can be respectively carried out in the reaction kettle, the equipment use cost is reduced, and the preparation efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of fine chemicals, specifically relating to a preparation device and process for p-fluorobenzoyl chloride. Background Technology

[0002] p-Fluorobenzoyl chloride is an important intermediate in the synthesis of pharmaceuticals, pesticides, and other fine chemical products. It can be used to synthesize fungicides such as flumorpholine, lipid-lowering drugs such as rosuvastatin, and drugs for treating neurological disorders such as varanoslin. Therefore, it has significant application value. The simplest traditional method for preparing p-fluorobenzoyl chloride is to use p-fluorotoluene as a starting material, followed by chlorination, separation and purification, and distillation. This process requires at least a reaction vessel, intermediate tank, and distillation vessel, resulting in high equipment costs and large space requirements. Each piece of equipment can only perform one process at a time, and the mixture needs to be transferred after each process. This transfer process inevitably leads to a decrease in product purity, thus affecting product quality and preparation efficiency.

[0003] Chinese patent document CN202111219594.1 discloses a preparation system for a neopentyl glycol copolymer, including a reactor body. A discharge valve is fixedly connected to the center of the bottom of the reactor body. The reactor body includes an outer shell. The interior of the outer shell is divided into a mixing chamber, a transfer chamber, an esterification chamber, and a distillation chamber by an upper arc plate, a middle arc plate, and a lower arc plate fixedly connected from top to bottom. A discharge hole is opened in the center of the upper and lower arc plates, and several discharge grooves are evenly opened on the edge of the middle arc plate. A stirring assembly is set in the center of the outer shell. The stirring assembly rotates and moves up and down inside the outer shell. A drive stirring assembly is connected to the top of the outer shell. The operating drive assembly includes a stirring assembly comprising a stirring shaft. A plugging block, capable of sealing the leakage hole, is rotatably fitted onto the surface of the stirring shaft at the top of the central leakage hole on both the upper and middle arc plates. The drive assembly includes a motor fixedly connected to the top of the reactor body via a motor mount. A prism sleeve is slidably fitted onto the motor output shaft, with the bottom end of the prism sleeve fixedly connected to the top end of the stirring shaft. Electric push rods are fixedly connected to the top of the reactor body on both sides of the prism sleeve, and a bracket is fixedly connected between the top ends of the two electric push rods. A tray is fixedly connected to the top of the prism sleeve and at the top of the bracket, and the tray and bracket are rotatably connected by steel balls. In this application, the drive assembly uses electric push rods to drive the bracket to rise and fall, thereby causing the motor to rise and fall and drive the plugging block to close and open the leakage trough, enabling material flow. However, the drive assembly structure is relatively complex, requiring multiple drive components to cooperate, making it prone to failure. Furthermore, this application relies solely on a single plugging block for sealing, resulting in poor sealing of the distillation chamber and failing to meet the requirements of low-pressure distillation processes. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses a preparation device and process for p-fluorobenzoyl chloride, which solves the problems of numerous devices and high production costs in the prior art. By adopting an integrated reactor, multiple processes can be carried out in the same reactor, thereby improving the preparation efficiency.

[0005] The specific technical solution is as follows:

[0006] A device for preparing p-fluorobenzoyl chloride includes a reaction vessel, a cooling device connected to the reaction vessel, and a vacuum device. The reaction vessel has an inlet and an outlet at its upper and lower ends, respectively. Inside the reaction vessel, there is a lifting and separating device and a stirring device. The lifting and separating device includes an upper partition, a lower partition, and a driving device for lifting the upper partition. The upper partition has a sealing sleeve on its side that fits tightly against the inner wall of the reaction vessel. The lower partition is fixedly connected to the inner wall of the reaction vessel, so that the upper and lower partitions separate the inner cavity of the reaction vessel, forming a reaction chamber, a filtration chamber, and a distillation chamber from top to bottom, allowing different processes to be carried out at different locations within the reaction vessel. At least two guide rods are longitudinally arranged through the upper partition and fixed inside the reaction vessel cavity. A flow channel is provided in the middle of the guide rod. When the upper partition descends to the position of the flow channel on the guide rod, the mixture on the upper partition flows down through the flow channel to the lower partition and falls into the filtration chamber after being filtered by the filter screen device. The lower partition has several through holes, and each through hole has a filter screen device for filtering reactants at its lower end. The bottom surface of the upper partition has a sealing pin that fits into the through hole. The sealing pin is embedded in the through hole to seal the distillation chamber. The upper partition is driven to descend by the driving device and fit against the lower partition to press the mixture in the filtration chamber into the distillation chamber. The stirring device is used to stir the mixture in the reaction chamber, and a ring-shaped ultraviolet lamp is provided on the inner wall of the upper end of the reaction chamber. A mixing scraper assembly is provided in the distillation chamber, and the mixing scraper assembly is driven to rotate by the driving device.

[0007] The reactor is equipped with a side heating device and a bottom heating device on its side wall and bottom, respectively, which are used to heat the reaction chamber and the distillation chamber to meet different process requirements. The vacuum pump is connected to the distillation chamber through a pipeline and is used to adjust the vacuum level in the distillation chamber. The cooling device is connected to the distillation chamber through a pipeline and is used to cool and liquefy the gas discharged from the distillation chamber to obtain the product.

[0008] Furthermore, the side heating device and the bottom heating device are respectively disposed on the upper end of the side wall of the reactor and the bottom of the reactor. Both the side heating device and the bottom heating device include a shell sleeved on the outer wall of the reactor and a plurality of heating block assemblies disposed on the inner side of the shell. The plurality of heating block assemblies are respectively attached to the side wall of the reactor and the bottom of the reactor to achieve heating.

[0009] Furthermore, the stirring device includes a stirring motor, a drive sleeve, and a stirring frame assembly. The stirring motor is located at the top of the reactor, and the output end of the stirring motor is connected to the drive sleeve in the inner cavity of the reactor. The stirring frame assembly is installed on the side wall of the drive sleeve. The stirring frame assembly is located above the upper partition plate and stirs the mixture in the reaction chamber.

[0010] Furthermore, the driving device includes a lifting bracket, a lifting seat, a drive motor, and a transmission rod. The lifting bracket is located at the bottom of the reactor. The lifting seat is slidably mounted on the lifting bracket, and the lifting bracket is provided with an elastic support member for pressing the top of the lifting seat downwards. The drive motor is fixedly mounted at the bottom of the lifting seat, and the output end of the drive motor is connected to the bottom end of the transmission rod. The transmission rod is longitudinally positioned in the reactor and includes a lead screw section in the middle and upper and lower sliding rod sections at the top and bottom ends. The lead screw section is threadedly connected to a threaded seat in the upper partition, so that the lead screw section and the threaded seat cooperate to drive the upper partition to rise and fall; the top of the upper sliding rod section... The end is embedded in the drive sleeve for positioning; the upper end of the sliding rod section is slidably connected to the lower partition plate, and the lower partition plate achieves axial sealing with the sliding rod section through a rubber seal. A sealing sleeve is sleeved on the outer side of the lower end of the sliding rod section. The sealing sleeve is fixedly set at the bottom of the inner wall of the reactor. The inner wall of the sealing sleeve is also axially sealed with the sliding rod section through a rubber seal. The mixing scraper assembly is fixedly set on the sliding rod section. When the upper partition plate descends and is limited by the lower partition plate, the lifting seat, drive motor and transmission rod rise, so that the lead screw section separates from the threaded seat, so that the sliding rod section can drive the mixing scraper assembly to rotate continuously to achieve stirring.

[0011] Furthermore, the mixing and scraping assembly includes a mixing plate, the middle of which is fixedly connected to the sliding rod section. The two ends of the mixing plate are adapted to the shape of the inner wall of the bottom of the reactor. Soft scraping plates are provided at the bottom of both ends of the mixing plate. After the transmission rod descends, the scraping plates adhere to the inner wall of the bottom of the reactor and scrape and remove slag from the bottom of the distillation chamber.

[0012] Furthermore, the upper end of the through hole is provided with a flared groove with a conical structure, and the lower end of the through hole is provided with a stepped block. The filter device is installed on the stepped block. The diameter of the sealing pin is adapted to the inner diameter of the through hole. The upper end of the sealing pin is provided with a sealing seat that matches the size and shape of the flared groove. The bottom end of the sealing pin is tapered. At least two annular grooves are provided on the side wall of the sealing pin. An O-ring is fitted in the annular groove and fits against the inner wall of the through hole.

[0013] Furthermore, each of the upper partition plates is slidably connected to the guide rod via a bushing, and the inner wall of each bushing is provided with a sealing ring that fits tightly with the guide rod to achieve sealing.

[0014] Furthermore, the flow guiding channel is a plurality of vertically arranged flow guiding grooves distributed radially.

[0015] Furthermore, the cooling device includes a heat exchange tank, with a horizontal partition plate at the lower end of the inner cavity of the heat exchange tank. The partition plate forms a heat exchange chamber and a recovery chamber at the upper and lower ends of the heat exchange tank, respectively. A heat exchange water connector is provided at the upper and lower ends of one side of the heat exchange chamber. Heat exchange tubes are arranged in an S-shape inside the heat exchange chamber. One end of the heat exchange tube is connected to the upper end of the distillation chamber through a pipeline. The bottom end of the heat exchange tube is open and embedded downward into the recovery chamber. A drain valve is connected to the bottom of the recovery chamber.

[0016] This invention also provides a process for preparing p-fluorobenzoyl chloride, specifically including the following steps:

[0017] Step (1), raw material preparation: Mix benzoic acid and hydrofluoric acid in a certain proportion, slowly add them into the reaction chamber of the reactor through the feed port, and stir them with a stirring device to ensure that the reaction is mixed evenly;

[0018] Step (2), reaction: The mixture in the reaction chamber is slowly heated to between 50°C and 70°C by the side heating device, and the reaction is carried out at this temperature for 4 hours; at the same time, chlorine gas is injected into the reaction vessel under the irradiation of ultraviolet lamp;

[0019] Step (3), separation: After the reaction is completed, add diethyl ether or benzene to the reaction chamber of the reactor to extract the target product and separate it;

[0020] Step (4), filtration: The upper partition descends to the guide channel on the guide rod, so that the separated p-fluorobenzoyl chloride falls into the filter chamber through the guide channel. Then the upper partition continues to descend and is embedded into the through hole through the sealing pin, so that the p-fluorobenzoyl chloride in the filter chamber falls into the distillation chamber after pressure filtration.

[0021] Step (5), distillation: The filtered p-fluorobenzoyl chloride is further distilled. The bottom heating device heats the distillation chamber, while the mixing scraper stirs the mixture. The p-fluorobenzoyl chloride formed after the gaseous product is cooled and liquefied by the cooling device is the final product.

[0022] The beneficial effects of this invention are reflected in:

[0023] (1) By setting a fixed lower partition and a liftable upper partition inside the reactor, the reactor cavity is arranged from top to bottom as a reaction chamber, a filtration chamber and a distillation chamber, so that different processes can be carried out in the reactor, reducing equipment usage costs and improving preparation efficiency.

[0024] (2) When the upper partition is driven down to the guide channel of the guide rod by the driving device, the reaction liquid in the reaction chamber can flow down to the filter chamber through the guide channel. As the upper partition continues to descend and fits with the lower partition, the reaction liquid in the filter chamber can flow into the distillation chamber after pressure filtration, thereby improving the purity of the product. The overall structure is compact and reasonable, reducing the failure rate of the device and ensuring the stable operation of the equipment.

[0025] (3) The upper end of the distillation chamber of the present invention is sealed by the sealing pin of the upper partition plate and the through hole of the lower partition plate. The lower end of the distillation chamber is axially sealed by the rubber sealing element on the inner wall of the sealing sleeve and the sliding rod section. This ensures that the distillation chamber can be subjected to reduced pressure distillation under the action of the vacuum device, thus meeting the process requirements.

[0026] (4) The present invention provides a mixing scraping assembly in the distillation chamber. The mixing scraping assembly is driven to rotate by a transmission rod. When the upper partition plate descends to fit with the lower partition plate, the lead screw section continues to rotate and rises to disengage from the threaded seat, allowing the transmission rod to idle. This drives the mixing scraping assembly to rotate continuously for mixing operations. After distillation, the transmission rod descends under the action of the thread, allowing the mixing scraping assembly to fit with the bottom of the distillation chamber and perform scraping and slag removal operations. An elastic support is provided in the lifting bracket to press the lifting seat downward, so that the transmission rod is always subjected to a downward force, ensuring that the lead screw section can properly cooperate with the threaded seat and ensuring the stable operation of the equipment. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention.

[0028] Figure 2 This is a schematic diagram of the internal structure of the present invention.

[0029] Figure 3 This is a schematic diagram of the internal structure after the upper partition is lowered in this invention.

[0030] Figure 4 This is a schematic diagram of the lower partition in this invention.

[0031] Figure 5 This is a schematic diagram of the sealing pin in this invention.

[0032] Figure 6 for Figure 3 Enlarged diagram of point A in the middle.

[0033] Figure 7 for Figure 3 Enlarged diagram of point B in the middle.

[0034] Reactor 1, Support 101, Inlet 102, Outlet 103, Reaction Chamber 104, Filter Chamber 105, Distillation Chamber 106, Limiting Block 107, Baffle 108, Guide Rod 109, Flow Channel 1091, Ultraviolet Lamp 110, Upper Baffle 11, Threaded Seat 111, Sealing Sleeve 112, Sealing Pin 113, Sealing Seat 1131, O-ring 1132, Bushing 114, Lower Baffle 12, Through Hole 121, Flared Groove 1211, Step Block 1212, Filter Screen Device 1213, Drive Motor 13, Lifting Bracket 14, Lifting Seat 15, Transmission 16. Moving rod, 161. Lead screw section, 162. Upper sliding rod section, 163. Lower sliding rod section, 17. Sealing sleeve, 171. Rubber seal, 18. Elastic support, 19. Mixing scraper assembly, 191. Mixing plate, 192. Scraper, 2. Stirring device, 21. Stirring motor, 22. Drive sleeve, 23. Stirring frame assembly, 3. Side heating assembly, 31. Housing, 32. Heating block assembly, 4. Bottom heating device, 5. Cooling device, 51. Heat exchange tank, 52. Divider plate, 53. Heat exchange chamber, 54. Recovery chamber, 55. Hot water exchange connector, 56. Heat exchange pipe, 57. Drain valve, 6. Vacuum device. Detailed Implementation

[0035] To make the technical solution of this invention clearer and more explicit, the invention will be further described below with reference to the accompanying drawings. Any solution derived by equivalent substitution and conventional reasoning of the technical features of this invention falls within the protection scope of this invention. The fixed connections and fixed installations mentioned in this invention are all common connection methods in the mechanical field, including welding, bolt and nut connections, and screw connections.

[0036] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0037] Please see the appendix Figure 1-3This embodiment provides a device for preparing p-fluorobenzoyl chloride, including a reaction vessel 1, a cooling device 5 connected to the reaction vessel 1, and a vacuum device 6. The lower end of the reaction vessel 1 is provided with a support leg 101. The top and bottom ends of the reaction vessel 1 are both flat. The upper and lower ends of the reaction vessel 1 are respectively provided with a feed port 102 and a discharge port 103. Both the feed port 102 and the discharge port 103 are provided with valves to control the opening and closing. The discharge pipe is located at the edge of the bottom flat surface of the reaction vessel 1 to facilitate the discharge of material residue. The reactor 1 is equipped with a lifting and separating device and a stirring device 2. The lifting and separating device includes a circular upper partition 11, a lower partition 12, and a driving device for lifting the upper partition 11. The upper partition 11 has a sealing sleeve 112 that fits tightly against the inner wall of the reactor 1 on its side. The inner wall of the reactor 1 is provided with several limiting blocks 107 for limiting the rise of the upper partition 11. The lower partition 12 is fixedly connected to the inner wall of the reactor 1 on its side, so that the upper partition 11 and the lower partition 12 respectively seal and separate the inner cavity of the reactor 1, and form a reaction chamber 104, a filtration chamber 105, and a distillation chamber 106 from top to bottom in the inner cavity of the reactor 1, so that different processes can be carried out in different positions in the inner cavity of the reactor 1.

[0038] like Figure 4 As shown, four guide rods 109 are longitudinally arranged through the edge of the upper partition plate 11. The four guide rods 109 are evenly distributed. The lower end of the guide rod 109 is fixedly connected to the lower partition plate 12, and the upper end of the guide rod 109 is fixedly connected to the inner wall of the reactor 1 through a support. A flow channel 1091 is provided in the middle of the guide rod 109. The flow channel 1091 consists of several vertically arranged flow grooves distributed radially. The upper partition plate 11 is slidably connected to the guide rod 109 through bushings 114. The inner wall of the upper partition 11 is provided with a sealing ring that fits tightly with the guide rod 109 to achieve a seal. The upper surface of the upper partition 11 has a structure that is high in the middle and low at the edges, so that the reaction liquid on the upper partition 11 can flow to the edge of the upper partition 11. When the upper partition 11 descends to the position of the guide channel 1091 on the guide rod 109, the mixture on the upper partition 11 flows down to the lower partition 12 through the guide channel 1091 and falls into the filter chamber 105 after being filtered by the filter screen device 1213. The lower partition 12 has several through holes 121. The upper end of the through hole 121 has a flared groove 1211 with a conical structure. The lower inner wall of the through hole 121 has a stepped block 1212. The stepped block 1212 is equipped with a filter screen device 1213 for filtering reactants. The filter screen device 1213 includes a housing with openings at the top and bottom and a filter screen disposed in the housing. The housing is placed on the stepped block 1212 for easy replacement. The bottom surface of the upper partition 11 is provided with a sealing pin 113 that fits into the through hole 121. The sealing pin 113 is inserted into the through hole 121 to seal the distillation chamber 106. The upper partition 11 is driven by a driving device to descend and fit against the lower partition 12 to press the mixture in the filtration chamber 105 into the distillation chamber 106.

[0039] like Figure 5-6 As shown, the diameter of the sealing pin 113 is adapted to the inner diameter of the through hole 121. The upper end of the sealing pin 113 is provided with a sealing seat 1131 that is adapted to the size and shape of the flared groove 1211. The bottom end of the sealing pin 113 is tapered. At least two annular grooves are provided on the side wall of the sealing pin 113. An O-ring 1132 that fits against the inner wall of the through hole 121 is fitted in the annular groove.

[0040] The stirring device 2 is used to stir the mixture in the reaction chamber 104. The stirring device 2 includes a stirring motor 21, a drive sleeve 22, and a stirring frame assembly 23. The stirring motor 21 is located at the top of the reactor 1. The output end of the stirring motor 21 is connected to the drive sleeve 22 in the inner cavity of the reactor 1. The stirring frame assembly 23 is installed on the side wall of the drive sleeve 22. The stirring frame assembly 23 is located above the upper partition 11 and stirs the mixture in the reaction chamber 104. An annular ultraviolet lamp 110 is installed on the inner wall of the upper end of the reaction chamber 104. The ultraviolet lamp 110 can irradiate the reaction liquid in the reaction chamber 104.

[0041] The side wall and bottom of the reactor 1 are respectively provided with a side heating device and a bottom heating device 4. The side heating device and the bottom heating device 4 are used to heat the reaction chamber 104 and the distillation chamber 106 to meet different process requirements. The side heating device and the bottom heating device 4 are respectively located at the upper end of the side wall of the reactor 1 and the bottom of the reactor 1. The side heating device and the bottom heating device 4 each include a shell 31 sleeved on the outer wall of the reactor 1 and a number of heating block assemblies 32 disposed inside the shell 31. The heating block assembly 32 is a number of ceramic heating blocks. The number of heating block assemblies 32 are respectively attached to the side wall and the bottom of the reactor 1 to achieve heating.

[0042] like Figure 7As shown, the driving device includes a lifting bracket 14, a lifting seat 15, a drive motor 13, and a transmission rod 16. The lifting bracket 14 is located at the bottom of the reactor 1. The lifting bracket 14 includes four sliding rods arranged longitudinally at the bottom of the reactor 1. A ring-shaped limiting plate is horizontally arranged at the bottom end of the four sliding rods. The lifting seat 15 is slidably arranged longitudinally on the four sliding rods. Elastic support members 18 are sleeved on the four sliding rods to press the top of the lifting seat 15 downward. The elastic support member 18 is a spring. The elastic force of the elastic support member 18 is less than the frictional resistance between the sealing sleeve 112 and the inner wall of the reactor 1, so that the transmission rod 16 is always subjected to a downward force to ensure that the lead screw section 161 can properly cooperate with the threaded seat 111. A drive motor 13 is fixedly installed at the bottom of the lifting seat 15. The output end of the drive motor 13 is connected to the bottom end of the transmission rod 16. The transmission rod 16 extends upward through the bottom of the reactor 1 and is longitudinally arranged in the reactor 1. The transmission rod 16 includes a lead screw section 161 in the middle and an upper sliding rod section 162 and a lower sliding rod section 163 at the upper and lower ends. The lead screw section 161 is threadedly connected to the threaded seat 111 in the upper partition 11, so that the lead screw section 161 and the threaded seat 111 cooperate to drive the upper partition 11 to rise and fall. The top end of the upper sliding rod section 162 is movably embedded in the drive sleeve 22 for positioning. The upper end of the lower sliding rod section 163 is slidably connected to the lower partition 12, and the lower partition 12 is axially sealed with the lower sliding rod section 163 through a rubber seal 171. The lower outer side of the lower end of the lower sliding rod section 163 is sealed. A sealing sleeve 17 is fitted and fixedly installed at the bottom of the inner wall of the reactor 1. The inner wall of the sealing sleeve 17 is also axially sealed by a rubber sealing element 171 that fits against the sliding rod section 163. The rubber sealing element 171 is a rubber sealing sleeve. Several layers of annular rubber sheets are arranged from top to bottom on the inner wall of the rubber sealing sleeve. One end of each annular rubber sheet is tightly fitted against the side wall of the sliding rod section 163 to achieve a seal. A mixing scraper assembly 19 is fixedly installed on the sliding rod section 163. When the upper partition 11 descends and is limited by the lower partition 12, the lifting seat 15, the drive motor 13, and the transmission rod 16 rise, causing the lead screw section 161 to separate from the threaded seat 111. This allows the sliding rod section 163 to drive the mixing scraper assembly 19 to rotate continuously and achieve stirring.

[0043] In this embodiment, a mixing and scraping assembly 19 is provided in the distillation chamber 106. The mixing and scraping assembly 19 is driven to rotate by a driving device. The mixing and scraping assembly 19 includes a mixing plate 191, the middle of which is fixedly connected to the sliding rod section 163. The two ends of the mixing plate 191 are adapted to the shape of the inner wall of the bottom of the reactor 1, and the bottom of both ends of the mixing plate 191 are provided with soft scraping plates 192, such as high-temperature resistant rubber. After distillation, the transmission rod 16 descends under the action of the thread, so that the scraping plates 192 can adhere to the inner wall of the bottom of the reactor 1 and scrape the bottom of the distillation chamber 106 to remove slag, so as to prevent the bottom of the reactor from sticking due to heating or to discharge slag.

[0044] The vacuum pumping device 6 is connected to the upper end of the distillation chamber 106 via a pipeline and is used to adjust the vacuum level in the distillation chamber 106. The vacuum pumping device is a vacuum pump. The cooling device 5 is connected to the upper end of the distillation chamber 106 via a pipeline and is used to cool and liquefy the gas discharged from the distillation chamber 106 to obtain the product. A baffle 108 is provided at the upper end of the distillation chamber 106 to prevent the mixture from splashing upwards into the pipelines of the cooling device 5 and the vacuum pumping device 6.

[0045] The cooling device 5 includes a heat exchange tank 51. A partition plate 52 is horizontally provided at the lower end of the inner cavity of the heat exchange tank 51. The partition plate 52 makes the upper and lower ends of the heat exchange tank 51 form a heat exchange chamber 53 and a recovery chamber 54, respectively. A heat exchange water connector 55 is provided at the upper and lower ends of one side of the heat exchange chamber 53. Heat exchange tubes 56 are arranged in an S-shape inside the heat exchange chamber 53. One end of the heat exchange tube 56 is connected to the upper end of the distillation chamber 106 through a pipeline. The bottom end of the heat exchange tubes 56 is open and embedded downward into the recovery chamber 54. A drain valve 57 is connected to the bottom of the recovery chamber 54.

[0046] The working principle of the preparation equipment of the present invention is as follows: When preparing p-fluorobenzoyl chloride, the material is fed into the reaction vessel 1 through the feed port 102 and falls into the reaction chamber 104 at the upper end of the upper partition 11. Then, the stirring motor 21 drives the stirring frame assembly 23 to stir the mixture in the reaction chamber 104. At the same time, the side heating device heats the reaction chamber 104. After the stirring and mixing is completed, the drive motor 13 drives the transmission rod 16 to rotate forward, so that the lead screw section 161 and the threaded seat 111 cooperate to drive the upper partition 11 to descend to the guide channel 1091 of the guide rod 109. Then, the reaction liquid in the reaction chamber 104 flows down into the filter chamber 105 through the guide channel 1091. Part of the reaction liquid flows into the distillation chamber 106 after being filtered by the filter screen device 1213. Then, the drive motor 13 drives the transmission rod 16 to continue to descend, so that the upper partition 11 and the lower partition 12 are in contact. At the same time, the sealing pin 113 is embedded in the through hole 121 to achieve pressure filtration and sealing.

[0047] As the drive motor 13 continues to rotate forward, the upper partition 11, under the limiting action of the lower partition 12, causes the lead screw section 161 to move upward and drive the drive motor 13 and the lifting seat 15 to rise until the lead screw section 161 disengages from the threaded seat 111. At this time, the mixing scraper assembly 19 stirs the reaction liquid in the distillation chamber 106 and performs distillation under the heating action of the bottom heating device 4. At the same time, the vacuum device 6 reduces the pressure of the distillation chamber 106. After the vapor is cooled by the cooling device 5, it forms p-fluorobenzoyl chloride and is collected through the drain valve 57.

[0048] After distillation, the material in the distillation chamber 106 is discharged. By opening the discharge port 103, the drive motor 13 starts to reverse. Under the action of the elastic support member 18, the lead screw section 161 is reconnected to the upper partition plate 11, and the transmission rod 16 drives the drive motor 13 to descend. At the same time, the scraper plate 192 of the mixing scraper assembly 19 is brought into contact with the bottom of the distillation chamber 106. As the motor continues to reverse, it drives the upper partition plate 11 to rise. During this process, the scraper plate 192 scrapes off the material and residue and discharges it through the discharge port 103.

[0049] This invention also provides a process for preparing p-fluorobenzoyl chloride, specifically including the following steps:

[0050] Step (1), raw material preparation: Mix benzoic acid and hydrofluoric acid in a certain proportion, slowly add them into the reaction chamber of the reactor through the feed port, and stir with a stirring device to ensure that the reaction is mixed evenly.

[0051] Step (2), reaction: The mixture in the reaction chamber is slowly heated to between 50°C and 70°C by the side heating device, and the reaction is carried out at this temperature for 4 hours; at the same time, chlorine gas is injected into the reaction vessel under the irradiation of ultraviolet lamp.

[0052] Step (3), separation: After the reaction is completed, add diethyl ether or benzene to the reaction chamber of the reactor to extract the target product and separate p-fluorobenzoyl chloride.

[0053] Step (4), filtration: The drive device drives the upper partition to descend to the guide channel on the guide rod, so that the separated p-fluorobenzoyl chloride falls into the filter chamber through the guide channel. Then the upper partition continues to descend and is embedded into the through hole through the sealing pin, so that the p-fluorobenzoyl chloride in the filter chamber falls into the distillation chamber after pressure filtration. At the same time, the upper end of the distillation chamber is sealed. After filtration, impurities can be removed, making the reaction solution purer.

[0054] Step (5), distillation: The filtered p-fluorobenzoyl chloride is further distilled. The bottom heating device heats the distillation chamber, while the mixing scraper stirs the mixture. The p-fluorobenzoyl chloride formed after the gaseous product is cooled and liquefied by the cooling device is the final product.

[0055] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An apparatus for preparing p-fluorobenzoyl chloride, comprising a reaction vessel (1), a cooling device (5) connected to the reaction vessel (1), and a vacuum device (6), wherein the reaction vessel (1) is provided with an inlet (102) and an outlet (103) at its upper and lower ends, respectively, characterized in that, The reactor (1) is equipped with a lifting and separating device and a stirring device (2). The lifting and separating device includes an upper partition (11), a lower partition (12), and a driving device for lifting the upper partition (11). The upper partition (11) has a sealing sleeve (112) that fits tightly against the inner wall of the reactor (1) on its side. The lower partition (12) is fixedly connected to the inner wall of the reactor (1) on its side, so that the upper partition (11) and the lower partition (12) respectively separate the inner cavity of the reactor (1) and make the reactor (1) 1) The inner cavity is formed from top to bottom as a reaction chamber (104), a filtration chamber (105), and a distillation chamber (106), so that different processes can be carried out at different positions in the inner cavity of the reactor (1); at least two guide rods (109) are longitudinally arranged on the upper partition plate (11), the guide rods (109) are fixed in the inner cavity of the reactor (1), and the guide rods (109) are provided with a flow channel (1091) in the middle of the guide rods (109). When the upper partition plate (11) descends to the position of the flow channel (1091) on the guide rods (109), the upper partition plate (104) is closed. 1) The mixture flows downward through the guide channel (1091) to the lower partition (12) and falls into the filter chamber (105) after being filtered by the filter screen device (1213); the lower partition (12) is provided with a number of through holes (121), and each through hole (121) is provided with a filter screen device (1213) for filtering the reactants at its lower end, and the bottom surface of the upper partition (11) is provided with a sealing pin (113) that fits into the through hole (121), and the sealing pin (113) is embedded into the through hole (121) to achieve the desired effect. The distillation chamber (106) is sealed by a drive device that lowers the upper partition (11) and fits it against the lower partition (12) to press the mixture in the filtration chamber (105) into the distillation chamber (106); the stirring device (2) is used to stir the mixture in the reaction chamber (104), and an annular ultraviolet lamp (110) is provided on the inner wall of the upper end of the reaction chamber (104); a mixing scraper assembly (19) is provided in the distillation chamber (106), and the mixing scraper assembly (19) is driven to rotate by the drive device; The reactor (1) is equipped with a side heating device and a bottom heating device (4) on its side wall and bottom, respectively. The side heating device and the bottom heating device (4) are used to heat the reaction chamber (104) and the distillation chamber (106) to meet different process requirements. The vacuum device (6) is connected to the distillation chamber (106) through a pipeline and is used to adjust the vacuum degree in the distillation chamber (106). The cooling device (5) is connected to the distillation chamber (106) through a pipeline and is used to cool and liquefy the gas discharged from the distillation chamber (106) to obtain the product. The stirring device (2) includes a stirring motor (21), a drive sleeve (22), and a stirring frame assembly (23). The stirring motor (21) is located at the top of the reactor (1). The output end of the stirring motor (21) is connected to the drive sleeve (22) in the inner cavity of the reactor (1). The stirring frame assembly (23) is located on the side wall of the drive sleeve (22). The stirring frame assembly (23) is located above the upper partition (11) and stirs the mixture in the reaction chamber (104). The driving device includes a lifting bracket (14), a lifting seat (15), a drive motor (13), and a transmission rod (16). The lifting bracket (14) is located at the bottom of the reactor (1). The lifting seat (15) is slidably mounted on the lifting bracket (14). The lifting bracket (14) is provided with an elastic support member (18) for pressing the top of the lifting seat (15) downward. The drive motor (13) is fixedly mounted at the bottom of the lifting seat (15). The output end is connected to the bottom end of the transmission rod (16). The transmission rod (16) is longitudinally arranged in the reactor (1). The transmission rod (16) includes a lead screw section (161) located in the middle and an upper sliding rod section (162) and a lower sliding rod section (163) located at the upper and lower ends. The lead screw section (161) is threadedly connected to the threaded seat (111) in the upper partition (11), so that the lead screw section (161) and the threaded seat (111) cooperate to drive the upper partition (11) to rise and fall; the upper sliding rod section (162) and the lower sliding rod section (163) are connected to the bottom end of the transmission rod (162). 62) The top part is positioned in the drive sleeve (22); the upper end of the sliding rod section (163) is slidably connected to the lower partition plate (12), and the lower partition plate (12) is axially sealed with the sliding rod section (163) through a rubber seal (171). A sealing sleeve (17) is sleeved on the outer side of the lower end of the sliding rod section (163). The sealing sleeve (17) is fixedly set at the bottom of the inner wall of the reactor (1). The inner wall of the sealing sleeve (17) is also sealed with a rubber seal. (171) The axial seal is achieved by fitting the lower slide rod section (163), and the mixing scraper assembly (19) is fixedly installed on the lower slide rod section (163). When the upper partition (11) descends and is limited by the lower partition (12), the lifting seat (15), the drive motor (13) and the transmission rod (16) rise, so that the lead screw section (161) separates from the threaded seat (111), thereby enabling the lower slide rod section (163) to drive the mixing scraper assembly (19) to rotate continuously to achieve stirring; The mixing scraping assembly (19) includes a mixing plate (191), the middle part of which is fixedly connected to the sliding rod section (163). The two ends of the mixing plate (191) are adapted to the shape of the inner wall of the bottom end of the reactor (1), and soft scraping plates (192) are provided at the bottom of both ends of the mixing plate (191). After the transmission rod (16) descends, the scraping plates (192) are attached to the inner wall of the bottom end of the reactor (1) and scrape the material and remove slag from the bottom end of the distillation chamber (106). The upper end of the through hole (121) is provided with a flared groove (1211) with a conical structure, and a stepped block (1212) is provided on the inner wall of the lower end of the through hole (121). The filter device (1213) is provided on the stepped block (1212). The diameter of the sealing pin (113) is adapted to the inner diameter of the through hole (121). The upper end of the sealing pin (113) is provided with a sealing seat (1131) that is adapted to the size and shape of the flared groove (1211). The bottom end of the sealing pin (113) is tapered. At least two annular grooves are provided on the side wall of the sealing pin (113). An O-ring (1132) that fits against the inner wall of the through hole (121) is sleeved in the annular groove.

2. The apparatus for preparing p-fluorobenzoyl chloride as described in claim 1, characterized in that, The side heating device and the bottom heating device (4) are respectively located on the upper end of the side wall of the reactor (1) and the bottom of the reactor (1). The side heating device and the bottom heating device (4) each include a shell (31) sleeved on the outer wall of the reactor (1) and a number of heating block assemblies (32) located inside the shell (31). The number of heating block assemblies (32) are respectively attached to the side wall of the reactor (1) and the bottom of the reactor (1) to achieve heating.

3. The apparatus for preparing p-fluorobenzoyl chloride as described in claim 1, characterized in that, The upper partition (11) is slidably connected to the guide rod (109) through the bushing (114), and the inner wall of the bushing (114) is provided with a sealing ring that fits tightly with the guide rod (109) to achieve sealing.

4. The apparatus for preparing p-fluorobenzoyl chloride as described in claim 3, characterized in that, The flow channel (1091) consists of several vertically arranged flow channels distributed radially.

5. The apparatus for preparing p-fluorobenzoyl chloride as described in claim 1, characterized in that, The cooling device (5) includes a heat exchange tank (51). A partition plate (52) is horizontally provided at the lower end of the inner cavity of the heat exchange tank (51). The partition plate (52) makes the upper and lower ends of the heat exchange tank (51) form a heat exchange chamber (53) and a recovery chamber (54) respectively. A heat exchange water connector (55) is provided at the upper and lower ends of one side of the heat exchange chamber (53). Heat exchange tubes (56) are arranged in an S-shape inside the heat exchange chamber (53). One end of the heat exchange tube (56) is connected to the upper end of the distillation chamber (106) through a pipeline. The bottom ends of the heat exchange tubes (56) are all open and embedded downward into the recovery chamber (54). A drain valve (57) is connected to the bottom of the recovery chamber (54).

6. The preparation process for p-fluorobenzoyl chloride using the preparation equipment according to any one of claims 1-5, characterized in that, Specifically, the following steps are included: Step (1), raw material preparation: Mix benzoic acid and hydrofluoric acid in a certain proportion, and slowly add them into the reaction chamber (104) of the reactor (1) through the feed inlet (102), and stir them with the stirring device (2) to ensure that the reaction is mixed evenly; Step (2), reaction: The mixture in the reaction chamber (104) is slowly heated to between 50°C and 70°C by the side heating device, and the reaction is carried out at this temperature for 4 hours; at the same time, chlorine gas is injected into the reaction vessel (1) under the irradiation of ultraviolet lamp (110); Step (3), separation: After the reaction is completed, add diethyl ether or benzene to the reaction chamber (104) of the reaction vessel (1) to extract the target product and separate it; Step (4), filtration: The upper partition (11) descends to the guide channel (1091) on the guide rod (109), so that the separated p-fluorobenzoyl chloride falls down into the filter chamber (105) through the guide channel (1091). Then the upper partition (11) continues to descend and is embedded into the through hole (121) through the sealing pin (113), so that the p-fluorobenzoyl chloride in the filter chamber (105) falls into the distillation chamber (106) after pressure filtration. Step (5), distillation: The filtered p-fluorobenzoyl chloride is further distilled. The bottom heating device (4) heats the distillation chamber (106), while the mixing scraper assembly (19) stirs. The p-fluorobenzoyl chloride formed after the gaseous product is cooled and liquefied by the cooling device (5) is the final product.

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