A method for preparing a ticagrelor azinitro impurity

Abstract

The present application relates to the technical field of chemical synthesis, and particularly relates to a preparation method of a ticagrelor nitrosoamine impurity, and the specific reaction steps are as follows: S1. Ticagrelor is added into a solvent, and tert-butyl nitrite is added, stirring and reaction are carried out, the solvent is one or more of dichloromethane, dimethyl sulfoxide, acetonitrile, tetrahydrofuran and isopropanol; S2. After the reaction is completed, the reaction liquid is concentrated and dried under reduced pressure to obtain a crude product of the ticagrelor nitrosoamine impurity; S3. The crude product of the ticagrelor nitrosoamine impurity is stirred with silica gel, the ticagrelor nitrosoamine impurity is eluted out by using a petroleum ether: ethyl acetate solution with a ratio of 5:1 to a petroleum ether: ethyl acetate solution with a ratio of 2:1, and the ticagrelor nitrosoamine impurity is obtained after being concentrated and dried under reduced pressure. The control sample prepared in the present application can detect the content of the corresponding nitrosoamine impurity in ticagrelor, thereby providing a control basis for controlling the nitrosoamine impurity level of ticagrelor.

Description

Technical Field

[0001] This invention relates to the field of chemical synthesis technology, specifically to a method for preparing ticagrelor nitrosamine impurities. Background Technology

[0002] Ticagrelor belongs to the cyclopentyltriazolidine class of antiplatelet drugs. It exerts its antiplatelet aggregation effect by selectively inhibiting the P2Y12 receptor and is mainly used clinically for the prevention of thrombotic events in patients with acute coronary syndrome (ACS). Unlike prodrugs such as clopidogrel, ticagrelor is the active pharmaceutical ingredient itself and can take effect directly without hepatic metabolism, offering pharmacological advantages such as rapid onset of action and reversible inhibitory effects.

[0003] With the widespread use of ticagrelor globally, its drug quality standards have received increasing attention. Controlling genotoxic impurities is one of the key areas of drug safety regulation. Ticagrelor's molecular structure contains a secondary amino (-NH-) functional group, which, under specific conditions, can undergo N-nitrosation with nitrosating agents (such as nitrites and nitrite esters) to generate corresponding N-nitrosamine derivatives. Nitrosamine impurities have been classified as Group 2A or 2B carcinogens by the International Agency for Research on Cancer (IARC). Regulatory agencies such as the U.S. Food and Drug Administration (FDA), the European Medicines Agency (EMA), and the China National Medical Products Administration (NMPA) have successively issued guidelines for nitrosamine impurity control, requiring pharmaceutical manufacturers to conduct systematic risk assessments and implement strict limit controls on potential nitrosamine impurities.

[0004] Therefore, establishing a method for preparing a ticagrelor nitrosamine impurity reference standard with mild reaction conditions, high yield, and high product purity is of great practical application value and quality control significance for obtaining reference standard materials that meet quality standards and establishing sensitive and accurate quantitative detection methods. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a method for preparing nitrosamine impurities in ticagrelor. Using this reference standard, the content of corresponding nitrosamine impurities in ticagrelor can be detected, thereby providing a reference for controlling the nitrosamine impurity levels in ticagrelor.

[0006] The solution adopted by this invention to solve its technical problem is: a method for preparing ticagrelor nitrosamine impurities, the reaction route of which is as follows: The specific reaction steps are as follows: S1. Add ticagrelor to a solvent and add tert-butyl nitrite, stir and react, wherein the solvent is one or more of dichloromethane, dimethyl sulfoxide, acetonitrile, tetrahydrofuran, and isopropanol; S2. After the reaction is complete, the reaction solution is concentrated and dried under reduced pressure to obtain crude ticagrelor nitrosamine impurity; S3. Stir the crude ticagrelor nitrosamine impurity with silica gel, and elute the ticagrelor nitrosamine impurity with a 5:1 petroleum ether:ethyl acetate solution to a 2:1 petroleum ether:ethyl acetate solution. After concentration and drying under reduced pressure, the ticagrelor nitrosamine impurity is obtained.

[0007] Furthermore, the solvent is dichloromethane.

[0008] Furthermore, the solvent is a mixed solution of dichloromethane and isopropanol.

[0009] Furthermore, the volume ratio of dichloromethane to isopropanol is (85-95):(5-15).

[0010] Furthermore, the reaction temperature in step S1 is 25-30℃, and the reaction time is 13-15 hours.

[0011] The addition of isopropanol can improve the polar environment of the reaction system, increase the effective collision frequency between the substrate and the nitrosating agent, and thus accelerate the nitrosation reaction.

[0012] In summary, the beneficial effects of this invention are as follows: The reference standard prepared in this application can be used to detect the content of corresponding nitrosamine impurities in ticagrelor, thereby providing a reference for controlling the nitrosamine impurity level of ticagrelor. Furthermore, the experiment of this invention is carried out under near-neutral conditions, without the use of strong acids, strong bases, or high temperatures, effectively avoiding the risk of racemization of the six chiral centers in the ticagrelor molecule. The stereochemical configuration of the obtained ticagrelor nitrosamine impurities is consistent with the parent ticagrelor, ensuring the structural accuracy of the impurity reference standard.

[0013] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below. Attached Figure Description

[0014] Figure 1 The 1H NMR spectrum of ticagrelor nitrosamine impurity; Figure 2 The liquid chromatogram for ticagrelor nitrosamine impurity; Figure 3 This is the mass spectrum of the nitrosamine impurity in ticagrelor. Detailed Implementation

[0015] To make the content of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0016] Example 1 (1) Add 10g of ticagrelor to 100ml of acetonitrile and 10ml of tert-butyl nitrite. Stir well and continue stirring at room temperature for 24 hours.

[0017] (2) After the reaction was complete, the reaction solution was concentrated and dried under reduced pressure. The crude product was purified by silica gel column chromatography (100-200 mesh silica gel). First, petroleum ether:ethyl acetate = 5:1 (V / V) was used as elution, and TLC monitoring was performed until no impurity spots were observed. Then, the target product was eluted with petroleum ether:ethyl acetate = 2:1 (V / V), and fractions were collected. The combined purified fractions were analyzed by TLC. The combined solution was concentrated and dried under reduced pressure at 45°C to obtain 6 g of ticagrelor nitrosamine impurity, with a yield of 56.8%.

[0018] Example 2 (1) Add 10g of ticagrelor to 100ml of dimethyl sulfoxide and 10ml of tert-butyl nitrite. Stir well and continue stirring at room temperature for 24 hours.

[0019] (2) After the reaction was complete, 100 ml of water and 150 ml of ethyl acetate were added to the reaction solution for extraction. The aqueous phase was removed, and the organic phase was concentrated and dried under reduced pressure. The crude product was purified by silica gel column chromatography (100-200 mesh silica gel). First, petroleum ether:ethyl acetate = 5:1 (V / V) was used as the eluting solution, and TLC monitoring was performed until no impurity spots were observed. Then, the elution solution was changed to petroleum ether:ethyl acetate = 2:1 (V / V) to elute the target product. Fractions were collected, and the purified fractions were combined by TLC analysis. The combined solution was concentrated and dried under reduced pressure at 45 °C to obtain 5.3 g of ticagrelor nitrosyl impurity, with a yield of 50.2%.

[0020] Example 3 (1) Add 10g of ticagrelor to 100ml of tetrahydrofuran and 10ml of tert-butyl nitrite. After stirring evenly, continue stirring at room temperature for 24 hours. (2) After the reaction was complete, the reaction solution was concentrated and dried under reduced pressure. The crude product was purified by silica gel column chromatography (100-200 mesh silica gel). First, petroleum ether:ethyl acetate = 5:1 (V / V) was used as elution, and TLC monitoring was performed until no impurity spots were observed. Then, the elution was changed to petroleum ether:ethyl acetate = 2:1 (V / V) to elute the target product. Fractions were collected, and the purified fractions were combined by TLC analysis. The combined solution was concentrated and dried under reduced pressure at 45°C to obtain 6.6 g of ticagrelor nitrosyl impurity, with a yield of 62.5%.

[0021] Example 4 (1) Add 10g of ticagrelor to 100ml of dichloromethane and 10ml of tert-butyl nitrite. Stir well and continue stirring at room temperature for 24 hours. (2) After the reaction was complete, the reaction solution was concentrated and dried under reduced pressure. The crude product was purified by silica gel column chromatography (100-200 mesh silica gel). First, petroleum ether:ethyl acetate = 5:1 (V / V) was used as elution, and TLC monitoring was performed until no impurity spots were observed. Then, the elution was changed to petroleum ether:ethyl acetate = 2:1 (V / V) to elute the target product. Fractions were collected, and the purified fractions were combined by TLC analysis. The combined solution was concentrated and dried under reduced pressure at 45°C to obtain 7.5 g of ticagrelor nitrosyl impurity, with a yield of 71.1%.

[0022] Example 5 (1) Add 10g of ticagrelor to a mixed solvent of 90mL dichloromethane and 10mL isopropanol and stir to dissolve. Add 3.5mL of tert-butyl nitrite and stir at room temperature (25℃) for 13 hours. Monitor the reaction by thin-layer chromatography (TLC, petroleum ether: ethyl acetate = 2:1) until the starting material is basically gone.

[0023] (2) After the reaction is complete, the reaction solution is concentrated to dryness under reduced pressure below 40°C to obtain approximately 10.5g of crude ticagrelor nitrosamine impurity.

[0024] (3) The crude product was mixed into silica gel, packed into a column, and the impurities were eluted sequentially with petroleum ether:ethyl acetate = 5:1 (v / v), and the product was eluted with petroleum ether:ethyl acetate = 2:1 (v / v). The product fraction was collected, concentrated and dried under reduced pressure to obtain 7.8 g of ticagrelor nitrosamine impurity, with a yield of 74.4% (based on ticagrelor).

[0025] Example 6 (1) Add 10g of ticagrelor to a mixed solvent of 95mL dichloromethane and 5mL isopropanol and stir to dissolve. Add 3.5mL of tert-butyl nitrite and stir at room temperature (25℃) for 15 hours. Monitor by TLC until the starting material is basically gone.

[0026] (2) The reaction solution was concentrated and dried under reduced pressure to obtain approximately 10.4 g of crude product.

[0027] (3) The same column chromatography method as in Example 5 was used to purify the ticagrelor nitrosamine impurity to obtain 8.1 g, with a yield of 77.3%.

[0028] Example 7 (1) Add 10g of ticagrelor to a mixed solvent of 85mL dichloromethane and 15mL isopropanol and stir to dissolve. Add 3.5mL of tert-butyl nitrite and stir at room temperature (25℃) for 13.5 hours. Monitor by TLC until the starting material is basically gone.

[0029] (2) The reaction solution was concentrated and dried under reduced pressure to obtain approximately 10.3g of crude product.

[0030] (3) The same column chromatography method was used to purify the ticagrelor nitrosamine impurity to obtain 7.9 g, with a yield of 84.2% and an HPLC purity of 75.8%.

[0031] Example 8 (1) Add 10g of ticagrelor to a mixture of 90mL dichloromethane and 10mL isopropanol and stir to dissolve. Add 3.2mL of tert-butyl nitrite and stir at room temperature (25℃) for 14 hours. Monitor by TLC until the starting material is almost completely eliminated.

[0032] (2) The reaction solution was concentrated and dried under reduced pressure to obtain about 10.2g of crude product.

[0033] (3) The same column chromatography method was used to purify the ticagrelor nitrosamine impurity to obtain 7.7 g, with a yield of 86.1% and an HPLC purity of 73.6%.

[0034] The proton NMR spectrum, liquid chromatogram, and mass spectrum of the ticagrelor nitrosamine impurity in this embodiment are shown below. Figure 1 , Figure 2 and Figure 3 As shown.

[0035] The embodiments described above are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and modifications made by those skilled in the art based on the invention shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing ticagrelor nitrosamine impurities, characterized in that, The reaction route is as follows: The specific reaction steps are as follows: S1. Add ticagrelor to a solvent and add tert-butyl nitrite, stir and react, wherein the solvent is one or more of dichloromethane, dimethyl sulfoxide, acetonitrile, tetrahydrofuran, and isopropanol; S2. After the reaction is complete, the reaction solution is concentrated and dried under reduced pressure to obtain crude ticagrelor nitrosamine impurity; S3. Stir the crude ticagrelor nitrosamine impurity with silica gel, and elute the ticagrelor nitrosamine impurity with a 5:1 petroleum ether:ethyl acetate solution to a 2:1 petroleum ether:ethyl acetate solution. After concentration and drying under reduced pressure, the ticagrelor nitrosamine impurity is obtained.

2. The method for preparing ticagrelor nitrosamine impurities according to claim 1, characterized in that, The solvent is dichloromethane.

3. The method for preparing ticagrelor nitrosamine impurities according to claim 1, characterized in that, The solvent is a mixed solution of dichloromethane and isopropanol.

4. The method for preparing ticagrelor nitrosamine impurities according to claim 3, characterized in that, The volume ratio of dichloromethane to isopropanol is (85-95):(10-12).

5. The method for preparing ticagrelor nitrosamine impurities according to claim 4, characterized in that, The reaction temperature in step S1 is 25-30℃, and the reaction time is 13-15 hours.

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