Reduced pressure distillation device for producing dabigatran etexilate intermediate and use method

Abstract

The invention relates to the technical field of dabigatran etexilate production, and particularly discloses a reduced pressure distillation device for dabigatran etexilate intermediate production and a use method.The reduced pressure distillation device comprises a distillation retort, an exhaust pipe is arranged at the top of the distillation retort, a pressure reduction pipe is installed at the top of the distillation retort, and the pressure reduction pipe is connected with a pressure reduction pump; a sealing shell is mounted in the distillation retort, and a temperature control mechanism is mounted in the sealing shell; a driving motor is mounted at the bottom of the distillation tank; the output end of the driving motor is connected with a stirring rod. The depressurization pipe and the depressurization pump are arranged at the top of the distillation retort, the depressurization pump is started, part of gas in the distillation retort can be pumped away, the air pressure in the distillation retort is reduced, the boiling point of a solution can be reduced, the requirement of the solution for the temperature in the distillation process is reduced, consumed energy is correspondingly reduced, and the air pressure is reduced; and when the subsequent distilled gas enters the tank body with normal air pressure and is liquefied, the liquefied temperature can be reached more quickly.

Description

Technical Field

[0001] The invention belongs to the technical field of dabigatran etexilate production, and particularly relates to a vacuum distillation device for producing a dabigatran etexilate intermediate and a use method thereof. Background Art

[0002] In the process of producing dabigatran etexilate, a variety of intermediates need to be produced, and finally the obtained multiple intermediates are converted into dabigatran etexilate. One of the intermediates in the production process requires distillation of toluene, recovered toluene, DMF and other raw materials after the acyl chloride reaction, and the product produced after distillation is sent to the next process.

[0003] The existing distillation device has the following problems in the process of distilling raw materials:

[0004] First, the raw materials need to be heated during distillation, and the raw materials have a higher boiling point at normal pressure, so more energy is required for distillation;

[0005] Secondly, during the heating process of the raw materials, the heat exchange rate between the position closer to the heating device and the heating device is faster, which leads to uneven temperature at different parts of the raw materials and different distillation rates at different parts of the raw materials. For example, the raw materials at a certain distance from the heating device begin to vaporize, while the raw materials near the heating device are already at the boiling point. The raw materials at the boiling point are prone to generate a large number of bubbles and violent boiling, which will lead to insufficient purity of the distilled product and damage the tank body of the distillation tank.

[0006] Finally, distilling apparatus needs to discharge the remaining solution in it after distillation ends, and the remaining solution is located at the bottom of the still, which is difficult to be clear and clean, which just causes the solution of the last batch of the still easily remaining in the still, and the product purity at the remaining batch production places of the still can be affected.Therefore the application proposes a kind of dabigatran etcxilate intermediate production vacuum distillation apparatus and use method. Summary of the invention

[0007] The object of the present invention is to provide a kind of dabigatran etcxilate intermediate production vacuum distillation apparatus and use method, to solve the problem that above-mentioned background technology proposes.

[0008] To achieve the above object, the present invention provides the following technical scheme: a kind of dabigatran etcxilate intermediate production vacuum distillation apparatus, comprising a still, the still top is provided with a vent pipe, the still top is equipped with a pressure-reducing pipe, and the pressure-reducing pipe is connected to a pressure-reducing pump;

[0009] A sealed shell is installed inside the distillation tank, and a temperature control mechanism is installed inside the sealed shell;

[0010] A driving motor is installed at the bottom of the distillation tank, the output end of the driving motor is connected to a stirring rod, the stirring rod is inserted into the distillation tank, and a portion of the stirring rod inserted into the distillation tank is installed with a plurality of stirring blades;

[0011] A liquid discharge pipe is installed at the bottom of the distillation tank, and a liquid pushing assembly is provided at the bottom of the stirring rod;

[0012] The liquid pushing assembly includes a sleeve and a liquid pushing rack. A liquid pushing inclined plate is installed in the slide groove of the liquid pushing rack. The top of the liquid pushing inclined plate is provided with an inclined surface, which abuts against the lower end surface of the locking ring. The lower end surface of the locking ring includes an arc-shaped guide portion, a parallel portion, and a vertical portion. The arc-shaped guide portion, the parallel portion, and the vertical portion are connected end to end in sequence, and the vertical portion is aligned with the discharge pipe. A spring is installed between the liquid pushing inclined plate and the liquid pushing rack.

[0013] Preferably, the stirring blade comprises a transverse plate, and transverse ribs are installed at the middle positions of the front and rear ends of the transverse plate, and longitudinal ribs are installed on the transverse ribs at equal vertical intervals.

[0014] Preferably, the stirring rod is connected to two cleaning plates symmetrically distributed on both sides of the stirring rod. The cleaning plates and the stirring rod are connected by multiple connecting plates. The multiple connecting plates are distributed in a circular array around the center line of the stirring rod. The top of the cleaning plate is located on the lower side of the pressure reducing tube, and triangular plates are installed at both ends of the front and rear of the connecting plate.

[0015] Preferably, the top end of the cleaning plate is connected to a guide block, the cross-section of the guide block is set to an inverted convex shape, the guide block is connected to a guide rail, the guide rail is connected to the outer wall of the sealing shell through the top plate, and the lowest end of the cleaning plate is located on the upper side of the top end of the drainage pipe.

[0016] Preferably, a liquid pushing block is installed at one end of the liquid pushing inclined plate away from the stirring rod, the lower end surface of the liquid pushing block is in contact with the bottom end of the inner wall of the distillation tank, and a plurality of grooves are arranged at the bottom end of the liquid pushing block, and soft pads are installed in the grooves.

[0017] Preferably, an arc plate is installed on the liquid pushing inclined plate, the arc plate protrudes to the side away from the stirring rod, and a moon pressure groove is provided on the arc plate, the moon pressure groove is recessed to the side close to the stirring rod, and a straight plate is installed at the end of the arc plate, the track groove in the straight plate is connected to the L-shaped plate, and the L-shaped plate is connected to the sleeve.

[0018] A method for using a vacuum distillation device for producing a dabigatran etexilate intermediate comprises the following steps:

[0019] Step 1: Feeding: feeding the raw materials into the distillation tank;

[0020] Step 2: Sealing and reducing pressure: closing the valve inside the distillation tank, turning on the pressure reducing pump, and pumping out part of the gas in the distillation tank through the pressure reducing pipe to reduce the gas pressure inside the distillation tank;

[0021] Step 3: Heating distillation: Start the temperature control mechanism, which transfers heat to the inside of the raw material through the outer wall of the sealed shell. During this period, start the drive motor to stir the raw material so that the raw material is heated evenly;

[0022] Step 4: Drainage: After the distillation is completed, open the drainage pipe to discharge the solution at the bottom of the distillation tank.

[0023] Preferably, in the process of discharging the solution at the bottom of the distillation tank mentioned in step four, the drive motor is turned on, and the cleaning plate connected to the drive motor can push the solution adhering to the inner wall of the distillation tank to the bottom of the distillation tank, and the liquid pushing block connected to it will reciprocate toward the direction of the inner wall of the distillation tank during the rotation, pushing the solution at the bottom of the distillation tank into the drainage pipe.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The present invention sets a pressure reducing pipe and a pressure reducing pump on the top of the distillation tank. When the pressure reducing pump is started, part of the gas in the distillation tank can be extracted to reduce the air pressure in the distillation tank, which can reduce the boiling point of the solution. During the distillation process, the temperature requirement of the solution is reduced, and the energy consumed is also reduced accordingly. When the air pressure is reduced, the subsequent distilled gas enters the tank body with normal air pressure and is liquefied, it can reach the liquefaction temperature faster and the liquefaction speed is faster.

[0026] 2. When the remaining solution in the distillation tank is discharged, the driving motor is started to mobilize the liquid pushing inclined plate to rotate. When the liquid pushing inclined plate and the liquid pushing frame are rotated to the vertical position, the liquid pushing inclined plate will move to the side close to the discharge pipe under the action of the spring, and push the solution at the bottom of the distillation tank to move out of the discharge pipe. When it is rotated to the arc guide part, the liquid pushing inclined plate will move to the side away from the inner wall of the distillation tank under the squeezing of the arc guide part. When it is rotated to the parallel part, the relative position between the liquid pushing inclined plate and the sleeve remains unchanged. Repeating the above steps can allow the liquid pushing inclined plate to move back and forth, so that the remaining solution at the bottom of the distillation tank can enter the discharge pipe under the reciprocating push and be finally discharged, and no raw materials will remain in the distillation tank.

[0027] 3. The interior of the distillation tank of the present invention is provided with a stirring rod and stirring blades, which can promote the mixing of the raw materials inside the distillation tank. At the same time, the liquid pushing component connected to the bottom of the stirring rod can push the raw materials to rotate and move back and forth at the same time, allowing the raw materials to flow back and forth inside the distillation tank and between the inner walls of the distillation tank. In combination with the stirring blades, the raw materials can be heated evenly at all locations, and the distillation speed is the same, without local boiling. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The schematic diagram of the structure of the vacuum distillation apparatus for producing the intermediate of dabigatran etexilate in the present invention.

[0029] Figure 2 This is a schematic diagram of the internal structure of the vacuum distillation apparatus for producing the dabigatran etexilate intermediate of the present invention.

[0030] Figure 3 The second schematic diagram of the internal structure of the vacuum distillation apparatus for producing the dabigatran etexilate intermediate in the present invention.

[0031] Figure 4 The third schematic diagram of the internal structure of the vacuum distillation apparatus for producing the intermediate of dabigatran etexilate in the present invention.

[0032] Figure 5 It is a schematic diagram of the structure of the liquid pushing component in the present invention.

[0033] Figure 6 For the present invention Figure 5 Bottom view of .

[0034] In the figure: 1, distillation tank; 2, exhaust pipe; 3, pressure reducing pipe; 4, pressure reducing pump; 5, sealing shell; 6, temperature control mechanism; 7, driving motor; 8, stirring rod; 9, stirring blade; 901, horizontal plate; 902, horizontal rib; 903, longitudinal rib; 10, cleaning plate; 11, connecting plate; 12, triangular plate; 13, guide block; 14, guide rail; 15, top plate;

[0035] 16. Liquid pushing assembly; 1601. Sleeve; 1602. Liquid pushing frame; 1603. Liquid pushing inclined plate; 1604. Liquid pushing block; 1605. Locking ring; 1606. Arc-shaped guide part; 1607. Vertical part; 1608. Spring; 1609. Arc-shaped plate; 1610. Moon pressure groove; 1611. L-shaped plate; 17. Liquid discharge pipe. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Reference Figure 1-Figure 6A vacuum distillation device for producing a dabigatran etexilate intermediate comprises a distillation tank 1, an exhaust pipe 2 is arranged on the top of the distillation tank 1, a pressure reducing pipe 3 is installed on the top of the distillation tank 1, and the pressure reducing pipe 3 is connected to a pressure reducing pump 4. Before the solution is distilled, the pressure reducing pump 4 is started to extract part of the gas in the distillation tank 1 and reduce the air pressure in the distillation tank 1, so that the boiling point of the solution can be reduced. During the distillation process, the temperature requirement of the solution is reduced, the energy consumed is also reduced accordingly, and the air pressure is reduced. When the subsequent distilled gas enters the tank body with normal air pressure and is liquefied, it can reach the liquefaction temperature faster and the liquefaction speed is faster.

[0038] In the process of producing dabigatran etexilate, a variety of intermediates need to be produced, and finally the obtained multiple intermediates are converted into dabigatran etexilate. One of the intermediates in the production process requires distillation of toluene, recovered toluene, DMF and other raw materials after the acyl chloride reaction, and the product produced after distillation is sent to the next process.

[0039] Furthermore, a sealed shell 5 is installed inside the distillation tank 1, and a temperature control mechanism 6 is installed inside the sealed shell 5. The temperature control mechanism 6 is used to control the temperature of the raw materials entering therein, distill the raw materials, and convert part of the raw materials into a gaseous state. The temperature control mechanism 6 is arranged inside the sealed shell 5, and heat is conducted through the outer wall of the sealed shell 5. The temperature control mechanism 6 is not in direct contact with the raw materials.

[0040] Furthermore, a driving motor 7 is installed at the bottom of the distillation tank 1, and the output end of the driving motor 7 is connected to a stirring rod 8, which is inserted into the distillation tank 1. The part of the stirring rod 8 inserted into the distillation tank 1 is installed with a plurality of stirring blades 9. The side of the stirring blade 9 away from the stirring rod 8 is more likely to bend during the rotation. In order to prevent the stirring blade 9 from deforming, the stirring blade 9 includes a transverse plate 901. Transverse ribs 902 are installed at the middle position of the front and rear ends of the transverse plate 901. The transverse ribs 902 are vertically and evenly spaced longitudinal ribs 903. The transverse ribs 902 and the longitudinal ribs 903 can improve the integrity of the transverse plate 901, so that when the end of the transverse plate 901 away from the stirring rod 8 is subjected to force, the force can be transmitted to other positions of the transverse plate 901, so that the force is evenly applied to various parts of the transverse plate 901, so that the transverse plate 901 is not easy to bend or deform during the stirring of the raw materials.

[0041] Furthermore, as the raw material distillation progresses, the liquid level of the raw material will also decrease, and part of the raw material will remain on the inner wall of the sealed shell 5 and the distillation tank 1. In order to remove this part of the raw material and keep the distillation tank 1 clean, the stirring rod 8 is connected to two cleaning plates 10 symmetrically distributed on both sides of the stirring rod 8. The cleaning plates 10 are connected to the stirring rod 8 through a plurality of connecting plates 11. The plurality of connecting plates 11 are distributed in a circular array around the center line of the stirring rod 8. The top of the cleaning plate 10 is located at the lower side of the pressure reducing pipe 3. Triangular plates 12 are installed at the front and rear ends of the connecting plates 11. The connecting plates 11 are distributed in a circular array. When the stirring rod 8 rotates, the gravity at each location is the same, and the stirring rod 8 will not shake due to uneven gravity during the rotation.

[0042] It should be noted that the top of the cleaning plate 10 is connected to the guide block 13, the cross-section of the guide block 13 is set to an inverted convex shape, the guide block 13 is connected to the guide rail 14, and the guide rail 14 is connected to the outer wall of the sealing shell 5 through the top plate 15; the guide block 13 and the guide rail 14 are arranged on the top of the cleaning plate 10, and the purpose is to improve the stability of the cleaning plate 10 during the rotation process and avoid its shaking, so that the cleaning plate 10 will not collide with the inner wall of the distillation tank 1, the noise during operation is small, and the inside of the distillation tank 1 can also be protected.

[0043] Furthermore, a drainage pipe 17 is installed at the bottom of the distillation tank 1, the lowest end of the cleaning plate 10 is located on the upper side of the top of the drainage pipe 17, and a liquid pushing component 16 is provided at the bottom of the stirring rod 8. When the liquid pushing component 16 is started, it can push the solution remaining at the bottom to the drainage pipe 17;

[0044] Specifically, the liquid pushing component 16 includes a sleeve 1601 and a liquid pushing frame 1602. A liquid pushing inclined plate 1603 is installed in the slide groove of the liquid pushing frame 1602. A liquid pushing block 1604 is installed at one end of the liquid pushing inclined plate 1603 away from the stirring rod 8. The lower end surface of the liquid pushing block 1604 is in contact with the bottom end of the inner wall of the distillation tank 1. The bottom end of the liquid pushing block 1604 is provided with a plurality of grooves, and a soft cushion is installed in the groove. The top of the liquid pushing inclined plate 1603 is provided with an inclined surface, which is against the lower end surface of the locking ring 1605. The lower end surface of the locking ring 1605 includes an arc-shaped guide portion 1606, a parallel portion, and a vertical portion 1607. The arc-shaped guide portion 1606, the parallel portion, and the vertical portion 1607 are connected end to end in sequence, and the vertical portion 1607 is aligned with the discharge pipe 17. When the liquid pushing inclined plate 1603 and the liquid pushing frame 1602 rotate to the position of the vertical portion 1607, that is, Figure 5 , Figure 6In the position shown, the liquid-pushing inclined plate 1603 will move toward the side close to the drainage pipe 17 under the action of the spring 1608, push the solution at the bottom of the distillation tank 1 to move toward the side of the drainage pipe 17, push the remaining solution into the drainage pipe 17, and the remaining solution will be discharged from the drainage pipe 17 at last. When it rotates to the arc-shaped guide part 1606, the liquid-pushing inclined plate 1603 will move toward the side away from the inner wall of the distillation tank 1 under the pressure of the arc-shaped guide part 1606. When it rotates to the parallel part, the relative position between the liquid-pushing inclined plate 1603 and the sleeve 1601 remains unchanged. Repeating the above steps can make the liquid-pushing inclined plate 1603 move back and forth, and continuously push the solution at the bottom of the distillation tank 1 to flow toward the drainage pipe 17.

[0045] More specifically, a spring 1608 is installed between the liquid pushing inclined plate 1603 and the liquid pushing frame 1602, and an arc plate 1609 is installed on the liquid pushing inclined plate 1603, and the arc plate 1609 is convex to the side away from the stirring rod 8, and a moon pressure groove 1610 is provided on the arc plate 1609, and the moon pressure groove 1610 is concave to the side close to the stirring rod 8. A straight plate is installed at the end of the arc plate 1609, and the track groove in the straight plate is connected to the L-shaped plate 1611, and the L-shaped plate 1611 is connected to the sleeve 1601. The liquid-pushing inclined plate 1603 rotates together with the sleeve 1601 and other components, and the arc plate 1609 can also push the solution at the bottom of the distillation tank 1 to flow, and the moon pressure groove 1610 arranged therein is recessed toward the center, and can be used as an open container for storing the solution during the rotation process. When it rotates to the vertical part 1607, the liquid-pushing inclined plate 1603 moves, and the arc plate 1609 connected thereto will also move, and the solution contained in the moon pressure groove 1610 can be pushed to the side of the discharge pipe 17.

[0046] A method for using a vacuum distillation device for producing a dabigatran etexilate intermediate comprises the following steps:

[0047] Step 1: Feeding: feeding the raw materials into the distillation tank 1;

[0048] Step 2: Sealing and reducing pressure: closing the valve inside the distillation tank 1, turning on the pressure reducing pump 4, and extracting part of the gas inside the distillation tank 1 through the pressure reducing pipe 3 to reduce the gas pressure inside the distillation tank 1;

[0049] Step 3: Heating and distilling: Start the temperature control mechanism 6, which transfers heat to the inside of the raw material through the outer wall of the sealed shell 5. During this period, start the driving motor 7 to stir the raw material so that the raw material is heated evenly;

[0050] Step 4: Drainage: After the distillation is completed, open the drainage pipe 17 to discharge the solution at the bottom of the distillation tank 1. During this period, turn on the drive motor 7. The cleaning plate 10 connected to the drive motor 7 can push the solution adhering to the inner wall of the distillation tank 1 to the bottom of the distillation tank 1, and the liquid pushing block 1604 connected to it will reciprocate toward the direction of the inner wall of the distillation tank 1 during the rotation, pushing the solution at the bottom of the distillation tank 1 into the drainage pipe 17.

[0051] Working principle:

[0052] In the production process of dabigatran etexilate, it is necessary to first produce a variety of intermediates, and finally convert the intermediates into dabigatran etexilate. When producing one of the intermediates, it is necessary to distill raw materials such as toluene, recovered toluene, and DMF after the acyl chloride reaction;

[0053] Before distillation, the pressure inside the distillation tank 1 is reduced by a pressure reducing pump 4;

[0054] Then the temperature control mechanism 6 transfers the heat to the raw material in the distillation tank 1 through the outer wall of the sealed shell 5, during which the driving motor 7 drives the stirring rod 8 and the stirring blade 9 to rotate, so that the raw material is heated evenly.

[0055] After the distillation is completed, the corresponding drainage pipe 17 is opened. The liquid pushing rack 1602 and the liquid pushing inclined plate 1603 in the liquid pushing assembly 16 can push the solution to the side close to the drainage pipe 17 during the rotation process, so that the solution at the bottom of the distillation tank 1 is discharged from the drainage pipe 17.

[0056] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A dabigatran etcxilate intermediate production vacuum distillation apparatus, comprising a still (1), characterized in that: An exhaust pipe (2) is arranged on the top of the distillation tank (1), a pressure reducing pipe (3) is installed on the top of the distillation tank (1), and the pressure reducing pipe (3) is connected to a pressure reducing pump (4); A sealed housing (5) is installed inside the distillation tank (1), and a temperature control mechanism (6) is installed inside the sealed housing (5); A driving motor (7) is installed at the bottom of the distillation tank (1); the output end of the driving motor (7) is connected to a stirring rod (8); the stirring rod (8) is inserted into the distillation tank (1); and a portion of the stirring rod (8) inserted into the distillation tank (1) is installed with a plurality of stirring blades (9); A liquid discharge pipe (17) is installed at the bottom of the distillation tank (1), and a liquid pushing assembly (16) is arranged at the bottom of the stirring rod (8); The liquid pushing assembly (16) comprises a sleeve (1601) and a liquid pushing frame (1602). A liquid pushing inclined plate (1603) is installed in a slide groove in the liquid pushing frame (1602). A slope is arranged on the top of the liquid pushing inclined plate (1603), and the slope abuts against the lower end surface of the locking ring (1605). The lower end surface of the locking ring (1605) comprises an arc-shaped guide portion (1606), a parallel portion, and a vertical portion (1607). The arc-shaped guide portion (1606), the parallel portion, and the vertical portion (1607) are connected end to end in sequence, and the vertical portion (1607) is aligned with the liquid discharge pipe (17). A spring (1608) is installed between the liquid pushing inclined plate (1603) and the liquid pushing frame (1602).

2. a kind of dabigatran etcxilate intermediate according to claim 1 is produced using a vacuum distillation apparatus, it is characterized in that, The stirring blade (9) comprises a transverse plate (901), and transverse ribs (902) are installed at the middle positions of the front and rear ends of the transverse plate (901), and longitudinal ribs (903) are installed on the transverse ribs (902) at equal intervals.

3. a kind of dabigatran etcxilate intermediate according to claim 1 is produced using a vacuum distillation apparatus, it is characterized in that, The stirring rod (8) is connected to two cleaning plates (10) symmetrically distributed on both sides of the stirring rod (8); the cleaning plates (10) and the stirring rod (8) are connected via a plurality of connecting plates (11); the plurality of connecting plates (11) are distributed in a circular array around the center line of the stirring rod (8); the top end of the cleaning plate (10) is located at the lower side of the pressure reducing pipe (3); and triangular plates (12) are installed at both the front and rear ends of the connecting plate (11).

4. a kind of dabigatran etcxilate intermediate according to claim 3 is produced using a vacuum distillation apparatus, it is characterized in that, The top end of the cleaning plate (10) is connected to a guide block (13), the cross section of the guide block (13) is arranged in an inverted convex shape, the guide block (13) is connected to a guide rail (14), the guide rail (14) is connected to the outer wall of the sealing shell (5) through a top plate (15), and the lowest end of the cleaning plate (10) is located on the upper side of the top end of the drainage pipe (17).

5. a kind of dabigatran etcxilate intermediate according to claim 1 is produced using a vacuum distillation apparatus, it is characterized in that, A liquid pushing block (1604) is installed at one end of the liquid pushing inclined plate (1603) away from the stirring rod (8), and the lower end surface of the liquid pushing block (1604) is in contact with the bottom end of the inner wall of the distillation tank (1). The bottom end of the liquid pushing block (1604) is provided with a plurality of grooves, and soft pads are installed in the grooves.

6. a kind of dabigatran etcxilate intermediate according to claim 5 is produced using a vacuum distillation apparatus, it is characterized in that, The liquid pushing inclined plate (1603) is provided with an arc plate (1609), the arc plate (1609) protrudes toward the side away from the stirring rod (8), and the arc plate (1609) is provided with a moon pressure groove (1610), the moon pressure groove (1610) is recessed toward the side close to the stirring rod (8), and a straight plate is provided at the end of the arc plate (1609), the track groove in the straight plate is connected to the L-shaped plate (1611), and the L-shaped plate (1611) is connected to the sleeve (1601).

7. A method for using a vacuum distillation apparatus for producing a dabigatran etexilate intermediate, characterized in that: A method for using a dabigatran etexilate intermediate production vacuum distillation apparatus according to any one of claims 1 to 6, comprising the steps of: Step 1: Feeding: feeding the raw materials into the distillation tank (1); Step 2: Sealing and reducing pressure: closing the valve inside the distillation tank (1), starting the pressure reducing pump (4), and pumping out part of the gas inside the distillation tank (1) through the pressure reducing pipe (3) to reduce the gas pressure inside the distillation tank (1); Step 3: Heating and distilling: Start the temperature control mechanism (6), which conducts heat to the inside of the raw material through the outer wall of the sealed shell (5). During this period, start the driving motor (7) to stir the raw material so that the raw material is heated evenly. Step 4: Draining: After the distillation is completed, the drainage pipe (17) is opened to discharge the solution at the bottom of the distillation tank (1).

8. a kind of dabigatran etcxilate intermediate according to claim 7 is produced using the method for vacuum distillation apparatus, it is characterized in that, During the process of discharging the solution at the bottom of the distillation tank (1) mentioned in step 4, the driving motor (7) is turned on, and the cleaning plate (10) connected to the driving motor (7) can push the solution adhering to the inner wall of the distillation tank (1) to the bottom of the distillation tank (1), and the liquid pushing block (1604) connected thereto will reciprocate toward the inner wall of the distillation tank (1) during the rotation process, pushing the solution at the bottom of the distillation tank (1) into the liquid discharge pipe (17).

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