A method for purifying a selective beta3-adrenergic receptor agonist
By using a specific ratio of anhydrous ethanol and purified water to dissolve the crude mirabezon and combining it with a stepwise cooling method, acetylated impurities were successfully removed, improving the purity and yield of mirabezon and solving the problem of removing acetylated impurities that is difficult in the prior art.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING SUN-NOVO PHARM RES CO LTD
- Filing Date
- 2024-12-09
- Publication Date
- 2026-06-09
AI Technical Summary
Existing technologies are insufficient to effectively remove acetylated impurities in Mirabellon that have similar physicochemical properties, resulting in low product purity and yield.
The crude Mirabelon was dissolved in a specific ratio of anhydrous ethanol and purified water. Seed crystals were added and stirred to induce crystallization by step cooling. The temperature was controlled within the range of 0 to 10°C and stirred for 0.5 to 2 hours. Finally, the mixture was filtered, washed and dried.
It significantly reduced the content of acetylated impurities in Mirabelle, improved product purity, and maintained a high yield. The process flow is simple, clear, and easy to operate.
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Abstract
Description
Technical Field
[0001] This application belongs to the field of pharmaceutical preparations, and specifically relates to a purification method for a selective β3-adrenergic receptor agonist. Background Technology
[0002] Mirabelon is a selective β3-adrenergic receptor agonist that increases bladder capacity by stimulating β3-adrenergic receptors and relaxing detrusor smooth muscle. It is used to treat symptoms of overactive bladder (OAB), such as urge incontinence, urgency, and frequency.
[0003] There are multiple synthetic routes for Miraberon, and existing technical research (Chen Jiong et al., Schematic Diagram of Miraberon Synthesis Route) generally summarizes its synthesis as using 4-nitrophenylethylamine, 4-nitrophenylacetonitrile, 4-aminophenylethanol, or 4-aminophenylacetonitrile as raw materials. However, in studying the quality of Miraberon, the inventors discovered an impurity that is very similar to Miraberon and is extremely difficult to remove.
[0004] Further quality studies revealed that existing techniques (Zhang Jie, quality study of Mirabelon and synthetic process study of dextromethorphan hydrochloride) also showed that an acetylated impurity is generated during recrystallization purification of crude Mirabelon using ethyl acetate. This impurity has physicochemical properties very similar to Mirabelon, making it difficult to completely remove using conventional purification methods. The secondary amine structure present in Mirabelon is as follows:
[0005]
[0006] In the preparation of mirabegron, acetone is used to produce methyl methacrylate (MMA). The secondary amine structure of mirabegron (MMA) may undergo amidation with residual acetone or ethyl acetate in the reaction system, thereby generating mirabegron acetylated impurities. Additionally, under alkaline conditions, the dehydration reaction between ethanol and mirabegron (as in patent CN117658943A, which uses alkaline solution and ethanol during preparation and crystallization) may also produce mirabegron acetylated impurities. The generation mechanism is as follows:
[0007] Summary of the Invention
[0008] To address the difficulty in removing acetylated impurities with physicochemical properties very similar to mirabéron, and to improve the purity and yield of mirabéron, this invention provides a purification method for a selective β3-adrenergic receptor agonist, comprising the following steps:
[0009] (1) The crude selective β3-adrenergic receptor agonist was dissolved in anhydrous ethanol / purified water system, with the mass ratio of anhydrous ethanol to purified water being 0.5 to 0.65:1, to obtain a solution with a concentration of 0.01 to 0.3 g / ml;
[0010] (2) At 55-70℃, add seed crystals of selective β3-adrenergic receptor agonists, and gradually cool down to 0-10℃ while stirring to precipitate crystals;
[0011] (3) Filter, wash and dry to obtain a selective β3-adrenergic receptor agonist.
[0012] Further, the mass ratio of anhydrous ethanol to purified water in step (1) is 0.5 to 0.6:1.
[0013] Further, the mass ratio of anhydrous ethanol to purified water in step (1) is 0.5 to 0.54:1.
[0014] Furthermore, the concentration of the solution obtained in step (1) is 0.01 to 0.07 g / ml.
[0015] Furthermore, the temperature at which the seed crystals are added in step (2) is 60–65°C.
[0016] Furthermore, the temperature for stirring and crystallization in step (2) is 0–5 °C.
[0017] Furthermore, the step cooling rate described in step (2) is 5–15 °C / h.
[0018] Further, step (2) is specifically operated as follows: at 60-65℃, seed crystals of selective β3-adrenergic receptor agonists are added, and the reaction system is gradually cooled to 50-55℃ in a gradient manner with a cooling rate of 5-15℃ / h, and then further cooled to 0-5℃. Then, the system is stirred and crystallized at 0-5℃ for 0.5-2h.
[0019] Further, in step (2), the mass ratio of the selective β3-adrenergic receptor agonist seed crystal to the crude selective β3-adrenergic receptor agonist is 0.01 to 0.05:1.
[0020] On the other hand, the present invention provides a selective β3-adrenergic receptor agonist obtained according to the above method, wherein the selective β3-adrenergic receptor agonist is preferably mirabezone; and the content of acetylated impurities in the selective β3-adrenergic receptor agonist is ≤0.09%.
[0021] Compared with the prior art, the purification method for selective β3-adrenergic receptor agonists (hereinafter referred to as Mirabelon) provided by the present invention has the following beneficial effects:
[0022] The mirabéron purification method provided by this invention effectively reduces acetylated impurities in mirabéron, thereby ensuring high product purity. Furthermore, the yield of mirabéron prepared by this method is quite considerable. The entire process is simple, clear, and easy to operate. Attached Figure Description
[0023] Figure 1 This is the HPLC detection result of related substances in Example 1.
[0024] Figure 2 This is the HPLC detection result of related substances in Example 2.
[0025] Figure 3 This is the HPLC detection result of related substances in Example 3.
[0026] Figure 4 This is the HPLC detection result of related substances in Example 4.
[0027] Figure 5 The results are from the HPLC detection of related substances in Comparative Example 1.
[0028] Figure 6 The results are from the HPLC detection of related substances in Comparative Example 2.
[0029] Figure 7 The results are from the HPLC detection of related substances in Comparative Example 3.
[0030] Figure 8 The results are from the HPLC detection of related substances in Comparative Example 4.
[0031] Figure 9 The results are from the HPLC detection of related substances in Comparative Example 5.
[0032] Figure 10 The results are from the HPLC detection of related substances in Comparative Example 6.
[0033] Figure 11 The results are from the HPLC detection of related substances in Comparative Example 7.
[0034] Figure 12 The results are from the HPLC analysis of related substances in Comparative Example 8.
[0035] Figure 13 The results are from the HPLC detection of related substances in Comparative Example 9. Detailed Implementation
[0036] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.
[0037] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.
[0038] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; unless otherwise specified, the reagents and materials used in the following examples are commercially available.
[0039] To address the issue of high impurity content in Mirabelon, particularly the significant content of acetylated impurities, this invention conducts in-depth research and optimization of the existing refining process for crude Mirabelon. The specific operations include the following steps:
[0040] (1) Dissolve crude Mirabelon in an anhydrous ethanol / purified water system, wherein the mass ratio of anhydrous ethanol to purified water is 0.5 to 0.65:1, preferably 0.5 to 0.6:1, more preferably 0.5 to 0.54:1, for example 0.5:1, 0.51:1, 0.52:1, 0.53:1 or 0.54:1, but not limited to the listed values. Other unlisted values within this range are also applicable, to obtain a solution with a concentration of 0.01 to 0.3 g / ml. The solution concentration is preferably 0.01 to 0.1 g / ml, more preferably 0.05 to 0.07 g / ml, for example 0.05, 0.06 or 0.07, but not limited to the listed values. Other unlisted values within this range are also applicable.
[0041] The crude mirabéron product described in this invention can be prepared using existing technologies, such as those mentioned in existing technologies (Zhang Jie, Quality Study of Miraberon and Synthetic Process Study of Dextromethorphan Hydrochloride), as long as mirabéron can be obtained; or it can be purchased through other commercial channels.
[0042] The anhydrous ethanol / purified water mentioned in this invention refers to a solution obtained by mixing anhydrous ethanol and purified water.
[0043] (2) At 55–70°C, Mirabelle seed crystals are added, wherein the mass ratio of Mirabelle seed crystals to crude Mirabelle is 0.01–0.05:1, preferably 0.01–0.03:1, more preferably 0.01–0.015:1, for example 0.01:1, 0.011:1, 0.012:1, 0.013:1, 0.014:1 or 0.015:1, but not limited to the listed values, other unlisted values within this range are also applicable; then the temperature is gradually reduced to 0–10°C and stirred to precipitate crystals.
[0044] In one embodiment of the present invention: Miraberon seed crystals are added at 55–70°C, with a cooling rate of 5–15°C / h. The cooling rate can be 5°C / h, 6°C / h, 7°C / h, 8°C / h, 9°C / h, 10°C / h, 11°C / h, 12°C / h, 13°C / h, 14°C / h, or 15°C / h, but is not limited to the listed values; other unlisted values within this range are also applicable. The reaction system is gradually cooled to 50–55°C, then further cooled to 0–5°C, and then stirred at 0–5°C for 0.5–2 hours to induce crystallization.
[0045] In one specific embodiment of the present invention: Miraberon seed crystals are added at 60-65°C, and the reaction system is gradually cooled to 50-55°C in a gradient manner with a cooling rate of 10°C / h, and then further cooled to 0-5°C. Then, the mixture is stirred at 0-5°C for 0.5-2 hours to induce crystallization.
[0046] (3) Filtration, washing and drying to obtain Miraberon. The present invention does not limit the method of filtration, washing and drying; conventional methods in the art can be used.
[0047] The specific embodiments and comparative examples of the present invention are listed below, but the present invention is not limited to the following examples.
[0048] Example 1
[0049] (1) Dissolve 12g of crude Mirabelon in a mixture of 80g anhydrous ethanol and 160g purified water (mass ratio of anhydrous ethanol to purified water is 0.5:1, volume ratio is 0.63:1) to obtain a solution with a concentration of 0.05g / ml.
[0050] (2) The reaction system is heated to 60-65℃ and 0.12g of Miraberon seed crystals are added. The reaction system is gradually cooled to 50-55℃ in a gradient manner with a cooling rate of 10℃ / h, and then further cooled to 0-5℃. Then, the system is stirred at 0-5℃ for 1h to crystallize.
[0051] (3) After filtration, washing and drying, pure Miraberon can be obtained.
[0052] Example 2
[0053] Adjust the amount of anhydrous ethanol and purified water in step (1) as follows. Other process steps and conditions are the same as in Example 1.
[0054] (1) Dissolve 12g of crude Mirabelon in a mixture of 80g anhydrous ethanol and 148.0g purified water (mass ratio of anhydrous ethanol to purified water is 0.54:1, volume ratio is 0.69:1) to obtain a solution with a concentration of 0.05g / ml.
[0055] Example 3
[0056] Adjust the amount of anhydrous ethanol and purified water in step (1) as follows. Other process steps and conditions are the same as in Example 1.
[0057] (1) Dissolve 12g of crude Mirabelon in a mixture of 80g anhydrous ethanol and 133.5g purified water (mass ratio of anhydrous ethanol to purified water is 0.6:1, volume ratio is 0.76:1) to obtain a solution with a concentration of 0.06g / ml.
[0058] Example 4
[0059] Adjust the amount of anhydrous ethanol and purified water in step (1) as follows. Other process steps and conditions are the same as in Example 1.
[0060] (1) Dissolve 12g of crude Mirabelon in a mixture of 80g anhydrous ethanol and 123.0g purified water (mass ratio of anhydrous ethanol to purified water is 0.65:1, volume ratio is 0.82:1) to obtain a solution with a concentration of 0.06g / ml.
[0061] Comparative Example 1
[0062] Without refining, 12g of crude Mirabelon was directly subjected to the same washing and drying process as in step (3) of Example 1 to obtain Mirabelon.
[0063] Comparative Example 2
[0064] Adjust the amount of anhydrous ethanol and purified water in step (1) as follows. Other process steps and conditions are the same as in Example 1.
[0065] (1) Dissolve 12g of crude Mirabelon in 80g of anhydrous ethanol and 800.0g of purified water (mass ratio of anhydrous ethanol to purified water is 0.1:1, volume ratio is 0.13:1) to obtain a solution with a concentration of 0.01g / ml.
[0066] Comparative Example 3
[0067] Adjust the amount of anhydrous ethanol and purified water in step (1) as follows. Other process steps and conditions are the same as in Example 1.
[0068] (1) Dissolve 12g of crude Mirabelon in 80g of anhydrous ethanol and 400.0g of purified water (mass ratio of anhydrous ethanol to purified water is 0.2:1, volume ratio is 0.25:1) to obtain a solution with a concentration of 0.03g / ml.
[0069] Comparative Example 4
[0070] Adjust the amount of anhydrous ethanol and purified water in step (1) as follows. Other process steps and conditions are the same as in Example 1.
[0071] (1) Dissolve 12g of crude Mirabelon in 80g of anhydrous ethanol and 266.5g of purified water (mass ratio of anhydrous ethanol to purified water is 0.3:1, volume ratio is 0.38:1) to obtain a solution with a concentration of 0.03g / ml.
[0072] Comparative Example 5
[0073] Adjust the amount of anhydrous ethanol and purified water in step (1) as follows. Other process steps and conditions are the same as in Example 1.
[0074] (1) Dissolve 12g of crude Mirabelon in 80g of anhydrous ethanol and 114.5g of purified water (mass ratio of anhydrous ethanol to purified water is 0.7:1, volume ratio is 0.89:1) to obtain a solution with a concentration of 0.06g / ml.
[0075] Comparative Example 6
[0076] Adjust the rate of step cooling in step (2) to 20℃ / h. The specific operation is as follows: other process steps and conditions are the same as in Example 1.
[0077] (2) The reaction system is heated to 60-65℃ and 0.12g of Miraberon seed crystals are added. The reaction system is gradually cooled to 50-55℃ in a gradient manner with a cooling rate of 20℃ / h, and then further cooled to 0-5℃. Then, the system is stirred at 0-5℃ for 1h to crystallize.
[0078] Comparative Example 7
[0079] Adjust the step cooling rate in step (2) to 30℃ / h. The specific operation is as follows: other process steps and conditions are the same as in Example 1.
[0080] (2) The reaction system is heated to 60-65℃ and 0.12g of Miraberon seed crystals are added. The reaction system is gradually cooled to 50-55℃ in a gradient manner with a cooling rate of 30℃ / h, and then further cooled to 0-5℃. Then, the system is stirred at 0-5℃ for 1h to crystallize.
[0081] Comparative Example 8
[0082] In step (2), the temperature control method is adjusted to constant temperature. The specific operation steps are as follows:
[0083] (1) Dissolve 15.0g of crude Mirabelon in a mixture of 100.0g anhydrous ethanol and 200.0g purified water (mass ratio of anhydrous ethanol to purified water is 0.5:1) to obtain a solution with a concentration of 0.05g / ml.
[0084] (2) Add 0.15g of Mirabelle seed crystals at 20℃ and maintain the above temperature while stirring to crystallize for 1h.
[0085] (3) After filtration, washing and drying, pure Miraberon can be obtained.
[0086] Comparative Example 9
[0087] Referring to step (4) of Example 4 in patent CN117658943A, the specific operation steps are as follows:
[0088] (1) Dissolve 290g of crude Mirabelon in a mixture of 530g of anhydrous ethanol and 840g of purified water (mass ratio of anhydrous ethanol to purified water is 0.63:1, volume ratio is 0.80:1) to obtain a solution with a concentration of 0.21g / ml.
[0089] (2) The reaction system is heated to 65-75℃ and 3g of Miraberon seed crystals are added. Then the temperature is slowly lowered to 5-10℃ (the cooling rate is 5℃ / 10min), and the mixture is stirred to crystallize for 1h.
[0090] (3) After filtration, washing and drying, pure Miraberon can be obtained.
[0091] The yield, related substances, and purity of milaberione in Examples 1-4 and Comparative Examples 1-9 were determined.
[0092] Yield = Miraberon production / Miraberon crude feed amount * 100%
[0093] Related substances detection methods:
[0094] The relevant substances were tested by high performance liquid chromatography (Chinese Pharmacopoeia 2020 Edition, Part IV, General Chapter 0512).
[0095] Take an appropriate amount of this product, dissolve it in methanol, and dilute it with mobile phase A to prepare a solution containing approximately 1 mg of mirabezon per ml.
[0096] Accurately measure an appropriate amount of the test solution and dilute it with mobile phase A to prepare a solution containing approximately 1 μg of mirabezon per ml.
[0097] Accurately measure 1 ml of the control solution into a 10 ml volumetric flask, dilute with mobile phase A to prepare the scale, and shake well.
[0098] Chromatographic conditions: Octadecylsilane-bonded silica gel was used as the stationary phase (Waters Xbridge C18; 4.6 mm × 150 mm, 3.5 μm or equivalent column); mobile phase A was perchlorate buffer (7.0 g sodium perchlorate monohydrate dissolved in 1000 ml of water, pH adjusted to 1.0 with perchloric acid)-acetonitrile-tetrahydrofuran (850:100:50); mobile phase B was acetonitrile; gradient elution was performed according to the table below; flow rate was 1.0 ml / min; column temperature was 15 °C; detection wavelength was 250 nm; injection volume was 20 μl.
[0099] Table 1 Elution Procedure
[0100]
[0101] Table 2: Impurity Information
[0102]
[0103] Table 3. Test results of the examples and comparative examples.
[0104]
[0105]
[0106] From Table 3 and its appendix Figures 1-13 It can be seen that the crude mirabéron product (Comparative Example 1) contained a relatively high content of acetylated impurities (0.3841%). By controlling the ratio of ethanol to water and the purification temperature during the purification process (as in Examples 1-4), the acetylated impurities in mirabéron were significantly reduced, and the yield and purity were high. In Examples 2 and 4, the acetylated impurities were below the detection limit.
[0107] When the amount of anhydrous ethanol in the anhydrous ethanol / purified water system is too small (as in Comparative Examples 2-4) or too large (as in Comparative Example 5), although the purity of Mirabelon is good, the content of acetylated impurities is obviously high and the yield is also low.
[0108] Further investigation into the effect of purification temperature on the quality of Miraberon revealed that specific stepped cooling conditions were required during purification. If the cooling rate was too rapid (as in Comparative Examples 6 and 7), the content of acetylated impurities and process impurities was significantly higher, and the yield was also lower. In particular, Comparative Example 6 showed an acetylated impurity content (0.7%) that was even higher than that of the unpurified Comparative Example 1 (0.3841%). This demonstrates that purification temperature has a significant impact on the content of acetylated impurities. Even with isothermal purification, as in Comparative Example 8, the acetylated impurities were not significantly reduced, and the yield remained low. Using the initial dissolution temperature (65–75°C) and stirring crystallization temperature (5–10°C) mentioned in the existing patent (Comparative Example 9), along with a cooling rate of 30°C / h, resulted in Miraberon with not only a low yield but also a high content of acetylated impurities.
[0109] In summary, only by precisely controlling the amount of anhydrous ethanol and water used in the refining process, as well as the refining temperature, can we effectively ensure good yield, purity, and acetylated impurity content of Miraberon.
[0110] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.
Claims
1. A method for purifying a selective β3-adrenergic receptor agonist, characterized in that, Includes the following steps: (1) The crude selective β3-adrenergic receptor agonist was dissolved in anhydrous ethanol / purified water system, with the mass ratio of anhydrous ethanol to purified water being 0.5 to 0.65:1, to obtain a solution with a concentration of 0.01 to 0.3 g / ml; (2) At 55-70℃, add seed crystals of selective β3-adrenergic receptor agonists, and gradually cool down to 0-10℃ while stirring to precipitate crystals; (3) Filter, wash and dry to obtain a selective β3-adrenergic receptor agonist.
2. The refining method according to claim 1, characterized in that, The mass ratio of anhydrous ethanol to purified water in step (1) is 0.5 to 0.6:
1.
3. The refining method according to claim 2, characterized in that, The mass ratio of anhydrous ethanol to purified water in step (1) is 0.5 to 0.54:
1.
4. The refining method according to claim 3, characterized in that, The concentration of the solution obtained in step (1) is 0.01 to 0.07 g / ml.
5. The refining method according to claim 4, characterized in that, The temperature at which the seed crystals are added in step (2) is 60-65℃.
6. The refining method according to claim 5, characterized in that, The temperature for stirring and crystallization in step (2) is 0-5℃.
7. The refining method according to claim 6, characterized in that, The step cooling rate described in step (2) is 5 to 15 °C / h.
8. The refining method according to claim 7, characterized in that, Step (2) is specifically performed as follows: at 60-65°C, add the seed crystals of the selective β3-adrenergic receptor agonist, and gradually cool the reaction system to 50-55°C in a gradient manner with a cooling rate of 5-15°C, and then continue to cool to 0-5°C. Then, stir and crystallize at 0-5°C for 0.5-2 hours.
9. The refining method according to claim 8, characterized in that, In step (2), the mass ratio of the selective β3-adrenergic receptor agonist seed crystal to the crude selective β3-adrenergic receptor agonist is 0.01 to 0.05:
1.
10. The selective β3-adrenergic receptor agonist obtained by the method according to any one of claims 1 to 9, wherein the selective β3-adrenergic receptor agonist is preferably mirabéron; and the content of acetylated impurities in the selective β3-adrenergic receptor agonist is ≤0.09%.