A process for the preparation of high purity gabapentin

Abstract

The application relates to the technical field of recrystallization, in particular to a preparation method of high-purity gabapentin, which comprises the following steps: S1, detecting first impurities and second impurities; S2, judging the opening and closing of a baffle according to the impurities; S3, conveying a preset weight of gabapentin to a preset working group; S4, opening the preset working group; S5, precipitating the first impurities and conveying a preset weight of gabapentin to the preset working group; S6, opening the preset working group; S7, precipitating the second impurities and recovering the impurities and the gabapentin; and S8, judging whether the recrystallization is completed or not. The special recrystallization device is added in the preparation method, the problems that the existing gabapentin recrystallization device has low production efficiency and cannot realize large-scale automatic production can be solved, the automatic degree in the recrystallization process is greatly increased, the problem that a large number of high-level technical personnel are needed to operate in the gabapentin recrystallization process is solved, the labor cost in the gabapentin recrystallization process is greatly reduced, and the economic benefits are increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of recrystallization, in particular to a preparation method of high-purity gabapentin. BACKGROUND

[0002] The gabapentin produced by the existing gabapentin preparation method has a high impurity content, and the existing gabapentin preparation methods are various, and the types of impurities in the prepared gabapentin are also different. Although gabapentin production enterprises will purify gabapentin according to their own preparation methods, the purity difference is large, and the phenomenon of not meeting the standard often occurs. However, in the traditional gabapentin recrystallization device, the degree of automation is low, a large amount of manpower needs to be invested, and the production efficiency is reduced. Therefore, there is an urgent need for a gabapentin recrystallization device capable of realizing automation to continuously produce high-purity gabapentin.

[0003] Chinese Patent Publication No. CN101785934B discloses a continuous recrystallization device and method, which comprises a distillation flask (6), a heat preservation condenser (7), and a reflux condenser (9), characterized in that: it further comprises a sand core filter (8), wherein the distillation flask (6), the heat preservation condenser (7), the sand core filter (8), and the reflux condenser (9) are connected in sequence from bottom to top; the sand core filter (8) is provided with a filtering cavity (10) and a heat preservation cavity (11), and the sand core filter (8) is provided with a sand core plate (1) installed at the lower end of the filtering cavity (10). The device and the operation method have the advantages of high recrystallization yield, low solvent loss, safety, and completely avoid the problems encountered in the traditional recrystallization method. It can be seen that the continuous recrystallization device and method have the problems of low production efficiency and inability to realize large-scale automated production. SUMMARY

[0004] Therefore, the present application provides a preparation method of high-purity gabapentin to overcome the problems of low production efficiency and inability to realize large-scale automated production of the gabapentin recrystallization device in the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides a preparation method of high-purity gabapentin, which comprises the following steps:

[0006] Step S1, using a high-performance liquid chromatograph and a gas chromatograph to detect the impurities in the gabapentin powder, and obtaining the first impurity type and the second impurity type in the gabapentin powder and their contents, respectively;

[0007] Step S2, the central control unit controls the opening and closing of the first baffle and the second baffle provided on the main conveying belt in the recrystallization special device according to the first impurity type and the second impurity type;

[0008] Step S3, the central control unit pours the preset weight of gabapentin powder into the main conveying belt, if the first baffle is opened, the main conveying belt pours the gabapentin powder into the first heating group, and the weight of the gabapentin powder poured into the first heating group each time is determined according to the content of the first impurity type, if the first baffle is closed, the main conveying belt conveys the gabapentin powder to the second baffle;

[0009] Step S4, the central control unit controls the working states of the first heating group, the second heating group, the first cooling group and the second cooling group according to the opening and closing of the first baffle respectively;

[0010] Step S5, the central control unit controls the corresponding reflux conveying belt to pour the preset weight of gabapentin powder into the second baffle of the main conveying belt, so that the gabapentin powder enters the third conveying belt, and the gabapentin powder is poured into the third heating group through the third conveying belt, and the weight of the gabapentin powder poured into the second heating group each time is determined according to the content of the second impurity type;

[0011] Step S6, the central control unit controls the working states of the third heating group and the fourth heating group according to the opening and closing of the second baffle respectively, and controls the working states of the third cooling group and the fourth cooling group according to the working states of the third heating group and the fourth heating group respectively;

[0012] Step S7, the central control unit determines the opening and closing of the collection baffles corresponding to the first collection conveying belt and the second collection conveying belt according to the comparison result of the first impurity type and the precipitation temperature of gabapentin in the first solvent, and determines the opening and closing of the collection baffles corresponding to the third collection conveying belt and the fourth collection conveying belt according to the comparison result of the second impurity type and the precipitation temperature of gabapentin in the second solvent, so that each collection conveying belt can pour the gabapentin powder into the main conveying belt and recycle the impurities;

[0013] Step S8, the central control unit controls the second reflux conveying belt to pour the gabapentin powder into the third baffle position of the main conveying belt, and controls the opening and closing of the third baffle according to the purity of the current gabapentin powder.

[0014] In step S1, the impurities in the gabapentin powder are detected by using a high-performance liquid chromatograph and a gas chromatograph, and the first impurity type and the second impurity type and their contents in the gabapentin powder are obtained, wherein the high-performance liquid chromatograph is used to automatically detect the first impurity type and its content, and the gas chromatograph is used to automatically detect the second impurity type and its content.

[0015] Specifically, the first impurity type is SSP amide impurities, and the second impurity type is EMA ester impurities, the first impurity type includes N-propionyl cysteine and N-propionyl-4-aminobenzoic acid, and the second impurity type includes methyl acetate and ethyl benzoate.

[0016] In step S2, the central control unit determines the opening and closing of the first baffle and the second baffle on the main conveying belt in the recrystallization device according to the data of the types of impurities contained in the gabapentin powder sent from the high-performance liquid chromatograph and the gas chromatograph, wherein,

[0017] When the gabapentin powder contains the first type of impurities, the central control unit controls the first baffle to open, blocks the gabapentin powder from advancing in the direction of movement of the main conveying belt, and makes the gabapentin powder fall into the first heating group under the action of the first baffle,

[0018] When the gabapentin powder contains the second type of impurities and does not contain the first type of impurities, the central control unit controls the first baffle to close and the second baffle to open, makes the gabapentin powder advance in the direction of movement of the main conveying belt at the position of the first baffle, and makes the gabapentin powder fall into the third heating group under the action of the second baffle,

[0019] When the gabapentin powder contains the first type of impurities and the second type of impurities, the central control unit controls the first baffle and the second baffle to open.

[0020] In step S3, the central control unit makes the main conveying belt fall the gabapentin powder of a preset weight into the main conveying belt, if the first baffle is open, the main conveying belt falls the gabapentin powder into the first heating group, and determines the weight of the gabapentin powder falling into the first heating group each time according to the content of the first type of impurities, if the first baffle is closed, the main conveying belt conveys the gabapentin powder to the second baffle, wherein the first heating group is internally provided with a first solvent of a preset capacity and concentration, the first solvent is used to dissolve the gabapentin powder of a preset weight and purity, the main conveying belt falls the gabapentin powder of a preset weight into the first heating group through intermittent movement, and the intermittent period of the intermittent movement of the main conveying belt corresponds to the switching period of each heating and pressurized sealed barrel in the first heating group.

[0021] In step S4, the central control unit controls the working states of the first heating group, the second heating group, the first cooling group, and the second cooling group according to the opening and closing of the first baffle, wherein the working states include opening and closing,

[0022] When the first baffle is open, the central control unit adjusts the working states of the first heating group, the second heating group, the first cooling group, and the second cooling group to opening, controls the first heating group and the second heating group to heat each corresponding heating and pressurized sealed barrel to a preset heating temperature, and controls the first cooling group and the second cooling group to cool each corresponding cooling and depressurized sealed barrel to a preset cooling temperature,

[0023] When the first baffle is closed, the central control unit adjusts the working states of the first heating group, the second heating group, the first cooling group, and the second cooling group to closing.

[0024] Specifically, the cooling temperature of the first cooling group is a first preset cooling temperature, the cooling temperature of the second cooling group is a second preset cooling temperature, the first preset cooling temperature > the second preset cooling temperature, the first preset cooling temperature is a precipitation temperature of the first precipitate, and the second preset cooling temperature is a precipitation temperature of the second precipitate.

[0025] In step S5, the central control unit controls the first return conveying belt to pour the gabapentin powder into the second baffle of the main conveying belt, if the second baffle is opened, the gabapentin powder enters the third heating group, and the weight of the gabapentin powder poured into the third heating group each time is determined according to the content of the second impurity type, if the second baffle is closed, the main conveying belt conveys the gabapentin powder to the third baffle, wherein the third heating group is internally provided with a second solvent with a preset capacity and concentration, the second solvent is used to dissolve the gabapentin powder with a preset weight and purity, the main conveying belt pours the gabapentin powder with a preset weight into the third heating group through intermittent movement, and the intermittent period of the intermittent movement of the main conveying belt corresponds to the switching period of each heating and pressurized sealed barrel in the third heating group.

[0026] In step S6, the central control unit controls the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group according to the opening and closing of the second baffle, wherein the working states include opening and closing,

[0027] When the second baffle is opened, the central control unit adjusts the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group to be opened, controls the third heating group and the fourth heating group to heat each corresponding heating and pressurized sealed barrel to a preset heating temperature, and controls the third cooling group and the fourth cooling group to cool each corresponding cooling and depressurized sealed barrel to a preset cooling temperature.

[0028] When the second baffle is closed, the central control unit adjusts the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group to be closed.

[0029] Specifically, the cooling temperature of the third cooling group is a third preset cooling temperature, the cooling temperature of the fourth cooling group is a fourth preset cooling temperature, the third preset cooling temperature > the fourth preset cooling temperature, the third preset cooling temperature is a precipitation temperature of the third precipitate, and the fourth preset cooling temperature is a precipitation temperature of the fourth precipitate.

[0030] In step S7, the central control unit determines the opening and closing of the collection flaps corresponding to the first and second collection conveyors according to the comparison results of the first impurity type and the precipitation temperature of gabapentin in the first solvent, and determines the opening and closing of the collection flaps corresponding to the third and fourth collection conveyors according to the comparison results of the second impurity type and the precipitation temperature of gabapentin in the second solvent, so that each collection conveyor can pour the gabapentin powder into the main conveyor and recycle the impurities. When the working state of any cooling group is open or closed, the central control unit adjusts the working state of the corresponding collection conveyor to open or close,

[0031] If the precipitate precipitated from any cooling group is an impurity, the central control unit controls the collection flap of the collection conveyor corresponding to the cooling group to close, and recycles the impurities,

[0032] If the precipitate precipitated from any cooling group is gabapentin, the central control unit controls the collection flap of the collection conveyor corresponding to the cooling group to open, so that the gabapentin passes through the corresponding collection conveyor and is conveyed to the corresponding reflux conveyor.

[0033] In step S8, the central control unit controls the second reflux conveyor to pour the gabapentin powder into the third flap position of the main conveyor. The central control unit controls the opening and closing of the third flap according to the comparison results of the purity of the current gabapentin powder and the preset purity,

[0034] If the purity of the current gabapentin powder meets the preset purity standard, the central control unit determines that the current recrystallization is complete, controls the third flap to close, and the main conveyor discharges the gabapentin powder after recrystallization,

[0035] If the purity of the current gabapentin powder does not meet the preset purity standard, the central control unit determines that the current recrystallization is not complete, controls the third flap to open, and the main conveyor transmits the gabapentin powder to another recrystallization device for secondary recrystallization.

[0036] In step S2, the recrystallization device includes a heating group, a cooling group, a conveying group, and a central control unit, wherein,

[0037] The heating group includes a first heating group, a second heating group, a third heating group and a fourth heating group, the first heating group is internally provided with a first solvent with a first preset heating temperature, the first solvent is used to dissolve gabapentin powder containing a first impurity type, the first heating group is used to heat the first solvent to the first preset heating temperature, the second heating group is used to heat the first solvent from which the first precipitate is precipitated to the second preset heating temperature, the third heating group is internally provided with a second solvent with a third preset heating temperature, the second solvent is used to dissolve gabapentin powder containing a second impurity type, the third heating group is used to heat the second solvent to the third preset heating temperature, and the fourth heating group is used to heat the second solvent from which the third precipitate is precipitated to the fourth preset heating temperature, and the heating group further includes a plurality of heating and pressurizing sealed barrels, and the heating group is used to heat and pressurize the preset solvent to the preset heating temperature and the preset pressure,

[0038] The heating and pressurizing sealed barrel includes a hot bottom plate with a filter hole, the hot bottom plate is arranged in the heating and pressurizing sealed barrel, when the hot bottom plate is located at the bottom of the heating and pressurizing sealed barrel, the hot bottom plate is attached to the protrusion at the bottom of the heating and pressurizing sealed barrel, the protrusion is inserted into the filter hole to prevent the preset solvent from flowing out of the filter hole, when the hot bottom plate is in the middle of the heating and pressurizing sealed barrel, the preset solvent flows out of the filter hole and the pores of the protrusion to the corresponding cooling group,

[0039] The cooling group includes a first cooling group, a second cooling group, a third cooling group and a fourth cooling group, the first cooling group is connected with the first heating group and the second heating group respectively, the first cooling group is used to cool the first solvent to the first preset cooling temperature and precipitate the first precipitate, the second cooling group is connected with the second heating group, the second cooling group is used to cool the first solvent from which the first precipitate is precipitated to the second preset cooling temperature and precipitate the second precipitate, the third cooling group is connected with the third heating group and the fourth heating group, the third cooling group is used to cool the second solvent to the third preset cooling temperature and precipitate the third precipitate, the fourth cooling group is connected with the fourth heating group, the fourth cooling group is used to cool the second solvent from which the third precipitate is precipitated to the fourth preset cooling temperature and precipitate the fourth precipitate, and the cooling group further includes a plurality of cooling and depressurizing sealed barrels, and the cooling group is used to cool and depressurize the preset solvent to the preset cooling temperature and the preset pressure,

[0040] The cooling and depressurizing sealed barrel includes a cold bottom plate with a filter hole and a scraper, the cold bottom plate is arranged in the cooling and depressurizing sealed barrel, when the cold bottom plate is located at the bottom of the cooling and depressurizing barrel, the cold bottom plate is attached to the protrusion at the bottom of the cooling barrel, the protrusion is inserted into the filter hole to prevent the preset solvent from flowing out of the filter hole, when the cold bottom plate is at the top of the cooling barrel, the filter screen in the filter hole filters out the crystals, the preset solvent passes through the filter screen and is left to the lower receiving groove, and the scraper is attached to the filter screen and is used to scrape out the precipitate outside the filter screen,

[0041] The first cooling group is arranged below the first heating group, the second heating group is arranged below the first cooling group, the second cooling group is arranged below the second heating group, the third cooling group is arranged below the third heating group, the fourth heating group is arranged below the third cooling group, and the fourth cooling group is arranged below the fourth heating group,

[0042] The conveying group comprises a main conveying belt, a first collecting conveying belt, a second collecting conveying belt, a third collecting conveying belt, a fourth collecting conveying belt, a first backflow conveying belt, and a second backflow conveying belt. The main conveying belt is provided with a first baffle, a second baffle, and a third baffle. The first baffle controls whether the gabapentin powder is fed into the first heating group by opening and closing. The second baffle controls whether the gabapentin powder is fed into the third heating group by opening and closing. The third baffle controls whether the gabapentin powder is fed into another recrystallization device or discharged after the recrystallization is completed by opening and closing. The main conveying belt is used to convey the gabapentin powder containing the first impurity type and the second impurity type or only containing the first impurity type to the first heating group. The main conveying belt is also used to convey the gabapentin powder containing only the second impurity type to the third heating group. The main conveying belt is also used to feed the gabapentin powder into another recrystallization device or discharge it,

[0043] The main conveying belt is used to convey the gabapentin powder containing the first impurity type and the second impurity type or only containing the first impurity type to the first heating group. The main conveying belt is also used to convey the gabapentin powder containing only the second impurity type to the third heating group. The main conveying belt is also used to feed the gabapentin powder into another recrystallization device or discharge it,

[0044] The first collecting conveying belt comprises a first collecting baffle. The first collecting baffle controls the conveying direction of the first precipitate on the first collecting conveying belt by opening and closing. The first collecting conveying belt is used to drive the first precipitate to move in a preset direction. The second collecting conveying belt comprises a second collecting baffle. The second collecting baffle controls the conveying direction of the second precipitate on the second collecting conveying belt by opening and closing. The second collecting conveying belt is used to drive the second precipitate to move in a preset direction. The third collecting conveying belt comprises a third collecting baffle. The third collecting baffle controls the conveying direction of the third precipitate on the third collecting conveying belt by opening and closing. The third collecting conveying belt is used to drive the third precipitate to move in a preset direction. The fourth collecting conveying belt comprises a fourth collecting baffle. The fourth collecting baffle controls the conveying direction of the fourth precipitate on the fourth collecting conveying belt by opening and closing. The fourth collecting conveying belt is used to drive the fourth precipitate to move in a preset direction,

[0045] The first backflow conveying belt comprises a first crushing device. The first crushing device is used to crush the gabapentin crystals to obtain gabapentin crushed powder. The first backflow conveying belt is used to convey the precipitated first precipitate or second precipitate to the second baffle position of the main conveying belt. The second backflow conveying belt comprises a second crushing device. The second crushing device is used to crush the gabapentin crystals to obtain gabapentin crushed powder. The second backflow conveying belt is used to convey the precipitated third precipitate or fourth precipitate to the third baffle position of the main conveying belt,

[0046] The central control unit is arranged on the special recrystallization device and is used to judge the working state and working power of the corresponding components according to the comparison result of the real-time detected current parameters and preset parameters, wherein the current parameters include the temperature in each heating and pressurizing barrel, the pressure in each heating and pressurizing barrel, the temperature in each cooling and depressurizing barrel, the pressure in each cooling and depressurizing barrel, the cycle of the intermittent movement of the main conveying belt, the purity of gabapentin powder, the weight of gabapentin powder input into the first heating group, the volume of solvent in each heating and pressurizing barrel and the dose of solvent in each heating and pressurizing barrel.

[0047] Compared with the prior art, the beneficial effects of the present application are that by adding the special recrystallization device in the preparation method, the problem of low production efficiency of the gabapentin recrystallization device in the prior art and the problem that large-scale automatic production cannot be realized can be overcome, the degree of automation in the recrystallization process is greatly increased, the problem that a large number of high-level technical personnel are needed to operate in the gabapentin recrystallization process is solved, the labor cost in the gabapentin recrystallization process is greatly reduced, and the economic benefit is increased. BRIEF DESCRIPTION OF DRAWINGS

[0048] The drawings described herein are used to provide further understanding of the present application, constitute a part of the present application, and the illustrative embodiments of the present application and the description thereof are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0049] Figure 1 It is a structural schematic diagram of the preparation method of high-purity gabapentin of the embodiment of the present application;

[0050] Figure 2 It is a side view structural schematic diagram of the special recrystallization device in the preparation method of high-purity gabapentin of the embodiment of the present application;

[0051] Figure 3 It is a top view structural schematic diagram of the special recrystallization device in the preparation method of high-purity gabapentin of the embodiment of the present application;

[0052] Figure 4 It is a schematic diagram of the heating and pressurizing sealed barrel of the special recrystallization device in the preparation method of high-purity gabapentin of the embodiment of the present application;

[0053] Figure 5 It is a schematic diagram of the cooling and depressurizing sealed barrel of the special recrystallization device in the preparation method of high-purity gabapentin of the embodiment of the present application;

[0054] In the figure, the main conveying belt 1, the second return conveying belt 2, the second crushing device 3, the third collecting conveying belt 4, the first crushing device 5, the first collecting conveying belt 6, the third collecting baffle 7, the first collecting baffle 8, the first baffle 9, the third heating group 10, the second baffle 11, the third baffle 12, the first heating group 13, the first heating group 14, the second heating group 15, the second cooling group 16, the third cooling group 17, the fourth heating group 18, the fourth cooling group 19, the scraper 20, the fourth collecting conveying belt 21, the second collecting conveying belt 22, the filter hole 23, the convex 24, the hot bottom plate 25, the filter screen 26, the first return conveying belt 27, the cold bottom plate 28. DETAILED DESCRIPTION

[0055] In order to make the objects and advantages of the present application clearer, the present application will be further described in conjunction with embodiments. It should be understood that the specific embodiments described herein merely serve the purpose of explaining the present application and are not intended to limit the present application.

[0056] The preferred embodiments of the present application will be described below with reference to the drawings. It should be understood by those skilled in the art that the embodiments are merely used to explain the technical principles of the present application and are not intended to limit the protection scope of the present application.

[0057] It should be noted that, in the description of the present application, the terms indicating the direction or positional relationship such as "upper", "lower", "left", "right", "inner", "outer", "middle" and the like are based on the direction or positional relationship shown in the drawings, which is merely for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0058] In addition, it should also be noted that, in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, or can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0059] Please refer to Figure 1 The present application provides a preparation method of high-purity gabapentin, as shown in the structure schematic diagram of the preparation method of high-purity gabapentin according to the embodiment of the present application. The embodiment includes the following steps:

[0060] In step S1, the impurities in the gabapentin powder are detected by using a high-performance liquid chromatograph and a gas chromatograph, and the first impurity type and the second impurity type in the gabapentin powder and their contents are obtained, respectively.

[0061] Step S2, the central control unit controls the opening and closing of the first baffle and the second baffle arranged on the main conveying belt in the recrystallization device according to the first impurity type and the second impurity type;

[0062] Step S3, the central control unit pours the preset weight of gabapentin powder into the main conveying belt, if the first baffle is opened, the main conveying belt pours the gabapentin powder into the first heating group, and judges the weight of the gabapentin powder poured into the first heating group each time according to the content of the first impurity type, if the first baffle is closed, the main conveying belt conveys the gabapentin powder to the second baffle.

[0063] Step S4, the central control unit controls the working states of the first heating group, the second heating group, the first cooling group and the second cooling group according to the opening and closing of the first baffle, respectively.

[0064] Step S5, the central control unit controls the corresponding reflux conveying belt to pour the preset weight of gabapentin powder into the second baffle of the main conveying belt, so that the gabapentin powder enters the third conveying belt, and the gabapentin powder is poured into the third heating group through the third conveying belt, and the weight of the gabapentin powder poured into the second heating group each time is judged according to the content of the second impurity type.

[0065] Step S6, the central control unit controls the working states of the third heating group and the fourth heating group according to the opening and closing of the second baffle, respectively, and controls the working states of the third cooling group and the fourth cooling group according to the working states of the third heating group and the fourth heating group, respectively.

[0066] Step S7, the central control unit judges the opening and closing of the collection baffles corresponding to the first collection conveying belt and the second collection conveying belt according to the comparison result of the first impurity type and the precipitation temperature of gabapentin in the first solvent, and judges the opening and closing of the collection baffles corresponding to the third collection conveying belt and the fourth collection conveying belt according to the comparison result of the second impurity type and the precipitation temperature of gabapentin in the second solvent, so that each collection conveying belt can pour the gabapentin powder into the main conveying belt and recycle the impurities.

[0067] Step S8, the central control unit controls the second reflux conveying belt to pour the gabapentin powder into the third baffle position of the main conveying belt, and controls the opening and closing of the third baffle according to the purity of the current gabapentin powder.

[0068] In step S1, the impurities in the gabapentin powder are detected by using a high performance liquid chromatograph and a gas chromatograph, and the first impurity type and the second impurity type and their contents in the gabapentin powder are obtained, wherein the high performance liquid chromatograph is used to automatically detect the first impurity type and its content, and the gas chromatograph is used to automatically detect the second impurity type and its content.

[0069] In the embodiment, the first impurity type is SSP amide impurities, the second impurity type is EMA ester impurities, the first impurity type includes N-propionyl cysteine and N-propionyl-4-aminobenzoic acid, and the second impurity type includes methyl acetate and ethyl benzoate.

[0070] In step S2, the central control unit determines the opening and closing of the first baffle and the second baffle on the main conveying belt in the recrystallization device according to the data of the types of impurities contained in the gabapentin powder sent from the high-performance liquid chromatograph and the gas chromatograph.

[0071] When the gabapentin powder contains the first impurity type, the central control unit controls the first baffle to open, blocks the gabapentin powder from advancing in the movement direction of the main conveying belt, and makes the gabapentin powder fall into the first heating group under the action of the first baffle.

[0072] When the gabapentin powder does not contain the first impurity type and contains the second impurity type, the central control unit controls the first baffle to close and the second baffle to open, makes the gabapentin powder advance in the movement direction of the main conveying belt at the position of the first baffle, and makes the gabapentin powder fall into the third heating group under the action of the second baffle.

[0073] When the gabapentin powder contains the first impurity type and the second impurity type, the central control unit controls the first baffle and the second baffle to open.

[0074] In step S3, the central control unit makes the main conveying belt fall the gabapentin powder of a preset weight into the main conveying belt. If the first baffle is open, the main conveying belt makes the gabapentin powder fall into the first heating group, and determines the weight of the gabapentin powder falling into the first heating group each time according to the content of the first impurity type. If the first baffle is closed, the main conveying belt conveys the gabapentin powder to the second baffle. The first heating group is internally provided with a first solvent of a preset capacity and concentration, which is used to dissolve the gabapentin powder of a preset weight and purity. The main conveying belt intermittently falls the gabapentin powder of a preset weight into the first heating group. The intermittent period of the intermittent movement of the main conveying belt corresponds to the switching period of each heating and pressurizing sealed barrel in the first heating group.

[0075] In step S4, the central control unit controls the working states of the first heating group, the second heating group, the first cooling group, and the second cooling group according to the opening and closing of the first baffle, wherein the working states include opening and closing.

[0076] When the first shutter is opened, the central control unit adjusts the working states of the first heating group, the second heating group, the first cooling group and the second cooling group to be opened, controls the first heating group and the second heating group to heat the corresponding each heating and pressurized sealed barrel to a preset heating temperature, and controls the first cooling group and the second cooling group to cool the corresponding each cooling and depressurized sealed barrel to a preset cooling temperature,

[0077] When the first shutter is closed, the central control unit adjusts the working states of the first heating group, the second heating group, the first cooling group and the second cooling group to be closed.

[0078] In the embodiment, the cooling temperature of the first cooling group is a first preset cooling temperature, the cooling temperature of the second cooling group is a second preset cooling temperature, the first preset cooling temperature > the second preset cooling temperature, the first preset cooling temperature is a precipitation temperature of the first precipitate, and the second preset cooling temperature is a precipitation temperature of the second precipitate.

[0079] In step S5, the central control unit controls the first return conveying belt to pour the gabapentin powder into the second shutter of the main conveying belt, and if the second shutter is opened, the gabapentin powder enters the third heating group, and the weight of the gabapentin powder poured into the third heating group each time is determined according to the content of the second impurity type, and if the second shutter is closed, the main conveying belt conveys the gabapentin powder to the third shutter, wherein the third heating group is internally provided with a second solvent with a preset capacity and concentration, the second solvent is used to dissolve gabapentin powder with a preset weight and purity, the main conveying belt intermittently moves to pour the gabapentin powder with a preset weight into the third heating group, and the intermittent period of the intermittent movement of the main conveying belt corresponds to the switching period of each heating and pressurized sealed barrel in the third heating group.

[0080] In step S6, the central control unit controls the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group according to the opening and closing of the second shutter, wherein the working states include opening and closing,

[0081] When the second shutter is opened, the central control unit adjusts the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group to be opened, controls the third heating group and the fourth heating group to heat the corresponding each heating and pressurized sealed barrel to a preset heating temperature, and controls the third cooling group and the fourth cooling group to cool the corresponding each cooling and depressurized sealed barrel to a preset cooling temperature,

[0082] When the second shutter is closed, the central control unit adjusts the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group to be closed.

[0083] In the embodiment, the cooling temperature of the third cooling group is a third preset cooling temperature, the cooling temperature of the fourth cooling group is a fourth preset cooling temperature, the third preset cooling temperature > the fourth preset cooling temperature, the third preset cooling temperature is the precipitation temperature of the third precipitate, and the fourth preset cooling temperature is the precipitation temperature of the fourth precipitate.

[0084] In step S7, the central control unit determines the opening and closing of the collection flaps corresponding to the first collection conveyor belt and the second collection conveyor belt according to the comparison result of the first impurity type and the precipitation temperature of gabapentin in the first solvent, and determines the opening and closing of the collection flaps corresponding to the third collection conveyor belt and the fourth collection conveyor belt according to the comparison result of the second impurity type and the precipitation temperature of gabapentin in the second solvent, so that each collection conveyor belt can pour the gabapentin powder into the main conveyor belt and recycle the impurities, wherein when the working state of any cooling group is opened or closed, the central control unit adjusts the working state of the corresponding collection conveyor belt to be opened or closed,

[0085] If the precipitate precipitated from any cooling group is an impurity, the central control unit controls the collection flaps of the collection conveyor belt corresponding to the cooling group to be closed, and recycles the impurities,

[0086] If the precipitate precipitated from any cooling group is gabapentin, the central control unit controls the collection flaps of the collection conveyor belt corresponding to the cooling group to be opened, so that the gabapentin is conveyed to the corresponding reflux conveyor belt through the corresponding collection conveyor belt.

[0087] In step S8, the central control unit controls the second reflux conveyor belt to pour the gabapentin powder into the main conveyor belt at the third flap position, and controls the opening and closing of the third flap according to the comparison result of the purity of the current gabapentin powder and the preset purity, wherein,

[0088] If the purity of the current gabapentin powder meets the preset purity standard, the central control unit determines that the current recrystallization is completed, controls the third flap to be closed, and the main conveyor belt discharges the gabapentin powder after recrystallization,

[0089] If the purity of the current gabapentin powder does not meet the preset purity standard, the central control unit determines that the current recrystallization is not completed, controls the third flap to be opened, and the main conveyor belt transmits the gabapentin powder to another recrystallization device for secondary recrystallization.

[0090] In step S2, the recrystallization device includes a heating group, a cooling group, a conveying group, and a central control unit, wherein,

[0091] The heating group includes a first heating group, a second heating group, a third heating group and a fourth heating group, the first heating group is internally provided with a first solvent with a first preset heating temperature, the first solvent is used to dissolve gabapentin powder containing a first impurity type, the first heating group is used to heat the first solvent to the first preset heating temperature, the second heating group is used to heat the first solvent from which the first precipitate is precipitated to the second preset heating temperature, the third heating group is internally provided with a second solvent with a third preset heating temperature, the second solvent is used to dissolve gabapentin powder containing a second impurity type, the third heating group is used to heat the second solvent to the third preset heating temperature, and the fourth heating group is used to heat the second solvent from which the third precipitate is precipitated to the fourth preset heating temperature, and the heating group further includes a plurality of heating and pressurizing sealed barrels, and the heating group is used to heat and pressurize the preset solvent to the preset heating temperature and the preset pressure,

[0092] The heating and pressurizing sealed barrel includes a hot bottom plate with a filter hole, the hot bottom plate is arranged in the heating and pressurizing sealed barrel, when the hot bottom plate is located at the bottom of the heating and pressurizing sealed barrel, the hot bottom plate is attached to the protrusion at the bottom of the heating and pressurizing sealed barrel, the protrusion is inserted into the filter hole to prevent the preset solvent from flowing out of the filter hole, when the hot bottom plate is in the middle of the heating and pressurizing sealed barrel, the preset solvent flows out of the filter hole and the pores of the protrusion to the corresponding cooling group,

[0093] The cooling group includes a first cooling group, a second cooling group, a third cooling group and a fourth cooling group, the first cooling group is connected with the first heating group and the second heating group respectively, the first cooling group is used to cool the first solvent to the first preset cooling temperature and precipitate the first precipitate, the second cooling group is connected with the second heating group, the second cooling group is used to cool the first solvent from which the first precipitate is precipitated to the second preset cooling temperature and precipitate the second precipitate, the third cooling group is connected with the third heating group and the fourth heating group, the third cooling group is used to cool the second solvent to the third preset cooling temperature and precipitate the third precipitate, the fourth cooling group is connected with the fourth heating group, the fourth cooling group is used to cool the second solvent from which the third precipitate is precipitated to the fourth preset cooling temperature and precipitate the fourth precipitate, and the cooling group further includes a plurality of cooling and depressurizing sealed barrels, and the cooling group is used to cool and depressurize the preset solvent to the preset cooling temperature and the preset pressure,

[0094] The cooling and depressurizing sealed barrel includes a cold bottom plate with a filter hole and a scraper, the cold bottom plate is arranged in the cooling and depressurizing sealed barrel, when the cold bottom plate is located at the bottom of the cooling and depressurizing barrel, the cold bottom plate is attached to the protrusion at the bottom of the cooling barrel, the protrusion is inserted into the filter hole to prevent the preset solvent from flowing out of the filter hole, when the cold bottom plate is at the top of the cooling barrel, the filter screen in the filter hole filters out the crystals, the preset solvent passes through the filter screen and is left to the lower receiving groove, and the scraper is attached to the filter screen and is used to scrape out the precipitate outside the filter screen,

[0095] The first cooling group is arranged below the first heating group, the second heating group is arranged below the first cooling group, the second cooling group is arranged below the second heating group, the third cooling group is arranged below the third heating group, the fourth heating group is arranged below the third cooling group, and the fourth cooling group is arranged below the fourth heating group,

[0096] The conveying group comprises a main conveying belt, a first collecting conveying belt, a second collecting conveying belt, a third collecting conveying belt, a fourth collecting conveying belt, a first backflow conveying belt, and a second backflow conveying belt. The main conveying belt is provided with a first baffle, a second baffle, and a third baffle. The first baffle controls whether the gabapentin powder is fed into the first heating group by opening and closing. The second baffle controls whether the gabapentin powder is fed into the third heating group by opening and closing. The third baffle controls whether the gabapentin powder is fed into another recrystallization device or discharged after the recrystallization is completed. The main conveying belt is used to convey the gabapentin powder containing the first impurity type and the second impurity type or only containing the first impurity type to the first heating group. The main conveying belt is also used to convey the gabapentin powder containing only the second impurity type to the third heating group. The main conveying belt is also used to feed the gabapentin powder into another recrystallization device or discharge it,

[0097] The main conveying belt is used to convey the gabapentin powder containing the first impurity type and the second impurity type or only containing the first impurity type to the first heating group. The main conveying belt is also used to convey the gabapentin powder containing only the second impurity type to the third heating group. The main conveying belt is also used to feed the gabapentin powder into another recrystallization device or discharge it,

[0098] The first collecting conveying belt comprises a first collecting baffle. The first collecting baffle controls the conveying direction of the first precipitate on the first collecting conveying belt by opening and closing. The first collecting conveying belt is used to drive the first precipitate to move in a preset direction. The second collecting conveying belt comprises a second collecting baffle. The second collecting baffle controls the conveying direction of the second precipitate on the second collecting conveying belt by opening and closing. The second collecting conveying belt is used to drive the second precipitate to move in a preset direction. The third collecting conveying belt comprises a third collecting baffle. The third collecting baffle controls the conveying direction of the third precipitate on the third collecting conveying belt by opening and closing. The third collecting conveying belt is used to drive the third precipitate to move in a preset direction. The fourth collecting conveying belt comprises a fourth collecting baffle. The fourth collecting baffle controls the conveying direction of the fourth precipitate on the fourth collecting conveying belt by opening and closing. The fourth collecting conveying belt is used to drive the fourth precipitate to move in a preset direction,

[0099] The first backflow conveying belt comprises a first crushing device. The first crushing device is used to crush the gabapentin crystals to obtain gabapentin crushed powder. The first backflow conveying belt is used to convey the precipitated first precipitate or second precipitate to the second baffle position of the main conveying belt. The second backflow conveying belt comprises a second crushing device. The second crushing device is used to crush the gabapentin crystals to obtain gabapentin crushed powder. The second backflow conveying belt is used to convey the precipitated third precipitate or fourth precipitate to the third baffle position of the main conveying belt,

[0100] The central control unit is arranged on the recrystallization special device and is used to judge the working state and working power of the corresponding components according to the comparison result of the real-time detected current parameters and the preset parameters, wherein the current parameters include the temperature in each heating and pressurizing barrel, the pressure in each heating and pressurizing barrel, the temperature in each cooling and depressurizing barrel, the pressure in each cooling and depressurizing barrel, the cycle of the intermittent movement of the main conveying belt, the purity of gabapentin powder, the weight of gabapentin powder input into the first heating group, the volume of solvent in each heating and pressurizing barrel, and the dose of solvent in each heating and pressurizing barrel.

[0101] In the embodiment, the recrystallization working process is as follows: the high-performance liquid chromatograph and the gas chromatograph are started to detect the impurities in the gabapentin powder, the contents of impurity A and impurity B are obtained respectively, the main conveying belt is started,

[0102] If there is no impurity A and no impurity B, the central control unit only starts the first baffle, the first heating group, the second heating group, the first cooling group, the second cooling group and the first reflux conveying belt. The central control unit judges the weight of the gabapentin powder added into the first heating group according to the proportion of impurity A in the gabapentin powder. The central control unit judges whether the first collected material and the second collected material are impurity A or gabapentin according to the high and low of the precipitation temperature of impurity A and gabapentin, and judges whether the first collecting conveying belt and the second collecting conveying belt are started according to the corresponding collecting baffles of the first collecting conveying belt and the second collecting conveying belt. After the gabapentin powder enters the first heating group, the central control unit judges whether the gabapentin powder is completely dissolved in the first solvent according to the time or machine vision. When the first heating group delivers the first solvent in the corresponding heating and pressurizing sealed barrel to the first cooling group, the first cooling group adjusts the temperature and pressure of the first solvent in the barrel to the first preset cooling temperature and the first preset depressurization pressure, the first collected material is precipitated. The cooling and depressurizing sealed barrel is lifted to the horizontal state with the upper top surface of the cooling and depressurizing sealed barrel, and the first solvent in which the first collected material is precipitated is delivered to the second heating group. At the same time, the scraper of the cooling and depressurizing sealed barrel scrapes the first collected material on the bottom plate to the first collecting conveying belt. The second heating group heats the first solvent in it to the preset heating temperature. The central control unit judges whether the first solvent is completely dissolved according to the time or machine vision. The completely dissolved first solvent is delivered from the second heating group to the second cooling group, and the second collected material is precipitated from the second cooling group. The second collected material is delivered from the second collecting conveying belt to the preset position, and the concentrated first solvent is collected. The collected material in the first collected material and the second collected material is the gabapentin crystal. The gabapentin crystal is crushed to the gabapentin powder with a preset particle size by the crushing device of the first reflux conveying belt, and is delivered from the first reflux conveying belt to the main conveying belt.

[0103] If there is impurity B and no impurity A, the central control unit only opens the second baffle, the central control unit only opens the second baffle, the third heating group, the fourth heating group, the third cooling group, the fourth cooling group and the second reflux conveying belt, the central control unit determines the weight of the gabapentin powder added to the third heating group according to the proportion of impurity B in the gabapentin powder, the central control unit determines whether the first precipitate and the second precipitate are impurity B or gabapentin according to the high and low of the precipitation temperature of impurity B and gabapentin, and determines whether the third collection conveying belt and the fourth collection conveying belt open the corresponding collection baffles according to the corresponding collection conveying belt of the third precipitate and the fourth precipitate, opens the third collection conveying belt and the fourth collection conveying belt at the same time, the precipitation process of the gabapentin powder after entering the third heating group is the same as the precipitation process of the gabapentin powder after entering the first heating group, the third precipitate and the fourth precipitate are obtained, and the gabapentin powder after crushing is transported to the main conveying belt by the first reflux conveying belt,

[0104] If there are impurities A and B, the central control unit opens the first baffle and the second baffle at the same time, first enters the first heating group to remove impurity A in the gabapentin powder, the gabapentin powder after precipitating impurity A is conveyed back to the main conveying belt through the first reflux conveying belt, and enters the third heating group through the second baffle to remove impurity B in the gabapentin, the gabapentin powder after precipitating impurity B is conveyed back to the main conveying belt through the second reflux conveying belt,

[0105] When the purity of the gabapentin powder after precipitating impurity B meets the preset purity standard, the third baffle is closed, and the gabapentin powder is conveyed to a preset position by the main conveying belt; when the purity of the gabapentin powder after precipitating impurity B does not meet the preset purity standard, the third baffle is opened, and the gabapentin powder is conveyed to another recrystallization device by the main conveying belt for recrystallization again.

[0106] In this embodiment, the first solvent is chloroform, and the second solvent is water or ethanol. The selection of the second solvent is determined according to the specific substance of the second impurity type, as long as it can meet the requirements of the solvent and different precipitation temperatures of gabapentin and EMA impurities in this embodiment, and the specific temperature is not described and limited.

[0107] In this embodiment, each preset heating temperature and each preset cooling temperature are determined according to the specific solvent type, impurity type and precipitation temperature, and the specific temperature is not described and limited in this embodiment.

[0108] In this embodiment, the number of recrystallization devices can be 0, 1 or 2, as long as it can meet the purity requirements of gabapentin recrystallization in this embodiment, and the specific temperature is not described and limited,

[0109] In this embodiment, the number of recrystallization devices is preferably 2.

[0110] In the embodiment, the heating group can be set in four, six or eight, as long as it can meet the requirement of the number of the precipitated substance in the embodiment, which will not be repeated.

[0111] In the embodiment, the heating group is preferably set in four, the cooling group is set in the same number as the heating group, and the collecting conveyor belt is set in the same number as the cooling group.

[0112] In the embodiment, the recrystallization process can be repeated once or multiple times, as long as it can meet the purity requirement of the gabapentin recrystallization in the embodiment, which will not be repeated.

[0113] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will fall within the protection scope of the present application.

[0114] The above description is only the preferred embodiments of the present application and is not used to limit the present application; for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the preparation of high purity gabapentin, characterized by, The application relates to a method for detecting and removing impurities in gabapentin powder. Step S1: detecting impurities in gabapentin powder by using a high-performance liquid chromatograph and a gas chromatograph, and obtaining the first impurity type and the second impurity type in the gabapentin powder and the contents of the impurities; Step S2: controlling the opening and closing of the first baffle and the second baffle arranged on the main conveying belt in the recrystallization device by the central control unit according to the first impurity type and the second impurity type; In the step S2, the central control unit judges the opening and closing of the first baffle and the second baffle on the main conveying belt in the recrystallization device according to the data of the types of the impurities in the gabapentin powder sent from the high-performance liquid chromatograph and the gas chromatograph, wherein, when the gabapentin powder contains the first impurity type, the central control unit controls the first baffle to open, blocks the gabapentin powder from moving forward along the movement direction of the main conveying belt, and makes the gabapentin powder fall into the first heating group under the action of the first baffle, when the gabapentin powder does not contain the first impurity type and contains the second impurity type, the central control unit controls the first baffle to close and controls the second baffle to open, makes the gabapentin powder move forward along the movement direction of the main conveying belt at the position of the first baffle, and makes the gabapentin powder fall into the third heating group under the action of the second baffle, when the gabapentin powder contains the first impurity type and the second impurity type, the central control unit controls the first baffle and the second baffle to open, makes the gabapentin powder first enter the first heating group to remove the first impurity type, then is conveyed back to the main conveying belt through the first reflux conveying belt, and falls into the third heating group through the second baffle to remove the second impurity type; Step S3: the central control unit puts the gabapentin powder with a preset weight into the main conveying belt, if the first baffle is open, the main conveying belt puts the gabapentin powder into the first heating group, and judges the weight of the gabapentin powder put into the first heating group each time according to the content of the first impurity type, if the first baffle is closed, the main conveying belt conveys the gabapentin powder to the second baffle; The first heating group is internally provided with the first solvent with a preset capacity and concentration, the first solvent is used for dissolving the gabapentin powder with a preset weight and purity, the main conveying belt intermittently puts the gabapentin powder with a preset weight into the first heating group, and the intermittent period of the intermittent movement of the main conveying belt corresponds to the switching period of each heating and pressurizing sealed barrel in the first heating group; Step S4: the central control unit controls the working states of the first heating group, the second heating group, the first cooling group and the second cooling group according to the opening and closing of the first baffle; Step S5: the central control unit controls the corresponding reflux conveying belt to put the gabapentin powder with a preset weight into the second baffle of the main conveying belt, makes the gabapentin powder enter the third conveying belt, and puts the gabapentin powder into the third heating group through the third conveying belt, and judges the weight of the gabapentin powder put into the third heating group each time according to the content of the second impurity type. Step S6, the central control unit controls the working state of the third heating group and the fourth heating group according to the opening and closing of the second baffle, and controls the working state of the third cooling group and the fourth cooling group according to the working state of the third heating group and the fourth heating group, respectively; Step S7, the central control unit judges the opening and closing of the collection baffle corresponding to the first collection conveyor belt and the second collection conveyor belt according to the comparison result of the first impurity type and the precipitation temperature of gabapentin in the first solvent, and judges the opening and closing of the collection baffle corresponding to the third collection conveyor belt and the fourth collection conveyor belt according to the comparison result of the second impurity type and the precipitation temperature of gabapentin in the second solvent, so that each collection conveyor belt can pour the gabapentin powder into the main conveyor belt and recycle the impurities; wherein, When the working state of any cooling group is on or off, the central control unit adjusts the working state of each collection conveyor belt corresponding to the cooling group to on or off, If the precipitate of any cooling group is impurity, the central control unit controls the collection baffle of the collection conveyor belt corresponding to the cooling group to close, and recycles the impurities, If the precipitate of any cooling group is gabapentin, the central control unit controls the collection baffle of the collection conveyor belt corresponding to the cooling group to open, so that the gabapentin passes through the corresponding collection conveyor belt and is conveyed to the corresponding reflux conveyor belt; Step S8, the central control unit controls the second reflux conveyor belt to pour the gabapentin powder into the main conveyor belt at the third baffle position, and controls the opening and closing of the third baffle according to the purity of the current gabapentin powder; wherein, If the purity of the current gabapentin powder meets the preset purity standard, the central control unit judges that the current recrystallization is completed, controls the third baffle to close, and the main conveyor belt discharges the gabapentin powder after recrystallization, If the purity of the current gabapentin powder does not meet the preset purity standard, the central control unit judges that the current recrystallization is not completed, controls the third baffle to open, and the main conveyor belt transmits the gabapentin powder to another recrystallization device for secondary recrystallization.

2. The process for the preparation of high purity gabapentin according to claim 1, characterized in that, In step S1, high performance liquid chromatography device and gas chromatography device are used to detect impurities in gabapentin powder, and the first impurity type and the second impurity type and their contents in the gabapentin powder are obtained, wherein the high performance liquid chromatography device is used to automatically detect the first impurity type and its content, and the gas chromatography device is used to automatically detect the second impurity type and its content.

3. The process for the preparation of high purity gabapentin according to claim 2, characterized in that, In step S4, the central control unit controls the working state of the first heating group, the second heating group, the first cooling group and the second cooling group according to the opening and closing of the first baffle, wherein the working state includes on and off. When the first shutter is opened, the central control unit adjusts the working states of the first heating group, the second heating group, the first cooling group and the second cooling group to be opened, controls the first heating group and the second heating group to heat the corresponding heating and pressurized sealed barrels to a preset heating temperature, and controls the first cooling group and the second cooling group to cool the corresponding cooling and depressurized sealed barrels to a preset cooling temperature. When the first shutter is closed, the central control unit adjusts the working states of the first heating group, the second heating group, the first cooling group and the second cooling group to be closed.

4. The process for the preparation of high purity gabapentin according to claim 3, characterized in that, In the step S5, the central control unit controls the first return conveying belt to pour the gabapentin powder into the second shutter of the main conveying belt, and if the second shutter is opened, the gabapentin powder enters the third heating group, and the weight of the gabapentin powder poured into the third heating group each time is determined according to the content of the second impurity type, and if the second shutter is closed, the main conveying belt conveys the gabapentin powder to the third shutter, wherein the third heating group is internally provided with the second solvent with a preset capacity and concentration, the second solvent is used to dissolve the gabapentin powder with a preset weight and purity, the main conveying belt intermittently moves to pour the gabapentin powder with a preset weight into the third heating group, and the intermittent period of the intermittent movement of the main conveying belt corresponds to the switching period of each heating and pressurized sealed barrel in the third heating group.

5. The process for the preparation of high purity gabapentin as claimed in claim 4 wherein, In the step S6, the central control unit controls the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group according to the opening and closing of the second shutter, wherein the working states include opening and closing. When the second shutter is opened, the central control unit adjusts the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group to be opened, controls the third heating group and the fourth heating group to heat the corresponding heating and pressurized sealed barrels to a preset heating temperature, and controls the third cooling group and the fourth cooling group to cool the corresponding cooling and depressurized sealed barrels to a preset cooling temperature. When the second shutter is closed, the central control unit adjusts the working states of the third heating group, the fourth heating group, the third cooling group and the fourth cooling group to be closed.

6. The process for the preparation of high purity gabapentin as claimed in claim 1 wherein, In the step S2, the recrystallization device includes a heating group, a cooling group, a conveying group and the central control unit, wherein The heating group includes the first heating group, the second heating group, the third heating group and the fourth heating group, the first heating group is provided with the first solvent with a first preset heating temperature, the first solvent is used to dissolve the gabapentin powder containing the first impurity type, the first heating group is used to heat the first solvent to the first preset heating temperature, the second heating group is used to heat the first solvent from which the first precipitate is precipitated to the second preset heating temperature, the third heating group is provided with the second solvent with a third preset heating temperature, the second solvent is used to dissolve the gabapentin powder containing the second impurity type, the third heating group is used to heat the second solvent to the third preset heating temperature, the fourth heating group is used to heat the second solvent from which the third precipitate is precipitated to the fourth preset heating temperature, and the heating group further includes a plurality of the heating and pressurizing sealed barrels, and the heating group is used to heat and pressurize the preset solvent to the preset heating temperature and the preset pressure, The heating and pressurizing sealed barrel includes a hot bottom plate with a filter hole, the hot bottom plate is arranged in the heating and pressurizing sealed barrel, when the hot bottom plate is located at the bottom of the heating and pressurizing sealed barrel, the hot bottom plate is attached to the protrusion at the bottom of the heating and pressurizing sealed barrel, the protrusion is inserted into the filter hole to prevent the preset solvent from flowing out of the filter hole, when the hot bottom plate is in the middle of the heating and pressurizing sealed barrel, the preset solvent flows out of the filter hole and the pores of the protrusion to the corresponding cooling group, The cooling group includes the first cooling group, the second cooling group, the third cooling group and the fourth cooling group, the first cooling group is connected to the first heating group and the second heating group respectively, the first cooling group is used to cool the first solvent to the first preset cooling temperature and precipitate the first precipitate, the second cooling group is connected to the second heating group, the second cooling group is used to cool the first solvent from which the first precipitate is precipitated to the second preset cooling temperature and precipitate the second precipitate, the third cooling group is connected to the third heating group and the fourth heating group, the third cooling group is used to cool the second solvent to the third preset cooling temperature and precipitate the third precipitate, the fourth cooling group is connected to the fourth heating group, the fourth cooling group is used to cool the second solvent from which the third precipitate is precipitated to the fourth preset cooling temperature and precipitate the fourth precipitate, and the cooling group further includes a plurality of cooling and depressurizing sealed barrels, and the cooling group is used to cool and depressurize the preset solvent to the preset cooling temperature and the preset pressure, The cooling and depressurizing sealed barrel includes a cold bottom plate with a filter hole and a scraper, the cold bottom plate is arranged in the cooling and depressurizing sealed barrel, when the cold bottom plate is located at the bottom of the cooling and depressurizing sealed barrel, the cold bottom plate is attached to the protrusion at the bottom of the cooling and depressurizing sealed barrel, the protrusion is inserted into the filter hole to prevent the preset solvent from flowing out of the filter hole, when the cold bottom plate is at the top of the cooling and depressurizing sealed barrel, the filter screen in the filter hole filters out the crystals, the preset solvent flows through the filter screen to the lower receiving groove, and the scraper is attached to the filter screen and is used to scrape out the precipitate outside the filter screen, The first cooling group is arranged below the first heating group, the second heating group is arranged below the first cooling group, the second cooling group is arranged below the second heating group, the third cooling group is arranged below the third heating group, the fourth heating group is arranged below the third cooling group, and the fourth cooling group is arranged below the fourth heating group, The conveying group comprises the main conveying belt, the first collecting conveying belt, the second collecting conveying belt, the third collecting conveying belt, the fourth collecting conveying belt, the first backflow conveying belt, and the second backflow conveying belt, wherein the main conveying belt is provided with the first baffle, the second baffle, and the third baffle, the first baffle controls whether the gabapentin powder is fed into the first heating group by opening and closing, the second baffle controls whether the gabapentin powder is fed into the third heating group by opening and closing, and the third baffle controls whether the gabapentin powder is fed into another recrystallization device or discharged after the recrystallization, The main conveying belt is used to convey the gabapentin powder containing the first impurity type and the second impurity type or containing only the first impurity type to the first heating group, is used to convey the gabapentin powder containing only the second impurity type to the third heating group, and is used to feed the gabapentin powder into another recrystallization device or discharge, The first collecting conveying belt comprises a first collecting baffle, the first collecting baffle controls the conveying direction of the first precipitate on the first collecting conveying belt by opening and closing, the first collecting conveying belt is used to drive the first precipitate to move in a preset direction, the second collecting conveying belt comprises a second collecting baffle, the second collecting baffle controls the conveying direction of the second precipitate on the second collecting conveying belt by opening and closing, the second collecting conveying belt is used to drive the second precipitate to move in a preset direction, the third collecting conveying belt comprises a third collecting baffle, the third collecting baffle controls the conveying direction of the third precipitate on the third collecting conveying belt by opening and closing, the third collecting conveying belt is used to drive the third precipitate to move in a preset direction, and the fourth collecting conveying belt comprises a fourth collecting baffle, the fourth collecting baffle controls the conveying direction of the fourth precipitate on the fourth collecting conveying belt by opening and closing, the fourth collecting conveying belt is used to drive the fourth precipitate to move in a preset direction, The first backflow conveying belt comprises a first crushing device, the first crushing device is used to crush the gabapentin crystal to obtain gabapentin crushed powder, the first backflow conveying belt is used to convey the precipitated first precipitate or second precipitate to the second baffle position of the main conveying belt, the second backflow conveying belt comprises a second crushing device, the second crushing device is used to crush the gabapentin crystal to obtain gabapentin crushed powder, and the second backflow conveying belt is used to convey the precipitated third precipitate or fourth precipitate to the third baffle position of the main conveying belt, The central control unit is arranged on the recrystallization device and is used to judge the working state and working power of the corresponding components according to the comparison result of the real-time detected current parameters and the preset parameters, wherein the current parameters include the temperature in each heating and pressurizing sealed barrel, the pressure in each heating and pressurizing sealed barrel, the temperature in each cooling and depressurizing sealed barrel, the pressure in each cooling and depressurizing sealed barrel, the cycle of the intermittent movement of the main conveying belt, the purity of gabapentin powder, the weight of gabapentin powder input into the first heating group, the volume of solvent in each heating and pressurizing sealed barrel and the dose of solvent in each heating and pressurizing sealed barrel.

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