N-noranisodamine nitrosamine impurity and synthesis method thereof

Abstract

The invention provides a method for preparing N-noranisodamine nitrosamine impurities with a structure as shown in a formula (I), which is characterized by comprising the following steps: A) mixing anisodamine hydrobromide, cupric acetate, ammonium persulfate and a solvent to react, concentrating under reduced pressure, extracting, and purifying by adopting a reverse phase silica gel column to obtain N-noranisodamine; and B) reacting the N-noranisodamine and sodium nitrite in the presence of a solvent and acid, and then extracting, filtering and concentrating to obtain the N-noranisodamine. The invention provides the method for preparing the NDSRI, a reference substance is provided for research on impurities of the anisodamine hydrobromide raw material medicine and the preparation, the quality control of the anisodamine hydrobromide raw material medicine and the preparation is improved, and the medicine safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of organic synthesis, and particularly relates to an N-norhyoscyamine nitrosamine impurity and a synthesis method thereof. Background Art

[0002] During the storage process in the production of raw materials and preparations of anisodamine hydrobromide, NDSRI impurities may be produced. This impurity is a genotoxic impurity of the nitrosamine type and is a strong carcinogen. A large number of animal experiments have shown that nitrosamines can cause cancer in the offspring of experimental animals through the placenta and milk. Therefore, strictly controlling the NDSRI impurities in raw materials and preparations of anisodamine hydrobromide plays a significant role in preventing and reducing potential drug safety hazards. The preparation of NDSRI impurities has not been reported and is not included in relevant quality standards. Summary of the Invention

[0003] In view of this, the technical problem to be solved by the present invention is to provide a synthesis method for N-norhyoscyamine nitrosamine impurity. The present invention discloses for the first time the synthesis and purification methods of the above-mentioned impurity, with simple methods, high purity and high yield.

[0004] The present invention provides an N-norhyoscyamine nitrosamine impurity with a structure of formula (I),

[0005]

[0006] The present invention provides a method for preparing an N-norhyoscyamine nitrosamine impurity with a structure of formula (I), which is characterized by including:

[0007] A) Mix anisodamine hydrobromide, copper acetate, ammonium persulfate and a solvent for reaction, concentrate under reduced pressure, and after extraction, purify using a reverse-phase silica gel column to obtain N-norhyoscyamine;

[0008] B) React N-norhyoscyamine with sodium nitrite in the presence of a solvent and an acid, and then obtain the product through extraction, filtration and concentration.

[0009] In some specific embodiments, the solvent in step A) is 40% acetonitrile; the molar ratio of anisodamine hydrobromide, copper acetate, and ammonium persulfate is 1:2:3.

[0010] In some specific embodiments, the temperature of the reaction in step A) is 25-35°C, and the reaction time is 20-24 h.

[0011] In some specific embodiments, the extraction in step A) includes:

[0012] Adjust the pH to 9.5 with 5% NaOH solution, extract with dichloromethane, extract the extraction solution with 2 volumes of 10% sulfuric acid, and adjust the pH of the aqueous phase extraction solution to 4.0-6.0.

[0013] In some specific embodiments, the elution conditions for purification by the reversed-phase silica gel column in step A) are as follows: from 0 to 45 minutes, using a 0.1% phosphoric acid solution as the mobile phase; from 45 to 60 minutes, eluting with a mobile phase of 0.1% phosphoric acid solution: acetonitrile = 20:80.

[0014] In some specific embodiments, after elution, the pH is adjusted to 9.5 with a 5% NaOH solution, followed by extraction with dichloromethane. The lower organic phase is collected, the extraction solutions are combined, dichloromethane is removed by reduced pressure concentration, dissolved in acetone at 60 °C, cooled and crystallized at 5 - 10 °C, filtered, and the filter cake is dried at 50 °C to obtain N-desmethyl anisodamine.

[0015] In some specific embodiments, the molar ratio of N-desmethyl anisodamine to sodium nitrite in step B) is 1:1 to 1:5.

[0016] The solvent is dichloromethane, and the acid is hydrochloric acid or formic acid; the addition amount of the acid is 0.5 - 5 times that of N-desmethyl anisodamine (volume-mass ratio, i.e., 0.5 - 5 ml of acid is added to 1 g of N-desmethyl anisodamine); the addition amount of dichloromethane is 5 - 300 times that of N-desmethyl anisodamine (volume-mass ratio, i.e., 5 - 300 ml of dichloromethane is added to 1 g of N-desmethyl anisodamine).

[0017] In some specific embodiments, the temperature of the reaction in step B) is 25 - 35 °C, and the reaction time is 3 - 4 h.

[0018] In some specific embodiments, the extraction in step B) is to adjust the pH to 10 - 11 by adding a 1% sodium hydroxide solution and extract with dichloromethane;

[0019] The dehydration is carried out using anhydrous sodium sulfate; the concentration is carried out by reduced pressure concentration at 40 °C.

[0020] Compared with the prior art, the present invention provides a method for preparing N-desmethyl anisodamine nitrosamine impurities with the structure of formula (I), which is characterized by including: A) mixing and reacting anisodamine hydrobromide, copper acetate, ammonium persulfate and a solvent, concentrating under reduced pressure, purifying by extraction with a reversed-phase silica gel column after extraction to obtain N-desmethyl anisodamine; B) reacting N-desmethyl anisodamine and sodium nitrite in the presence of a solvent and an acid, followed by extraction, filtration, and concentration to obtain the product. This patent provides a method for preparing NDSRI, provides a reference substance for the impurity research of anisodamine hydrobromide raw materials and preparations, is conducive to improving the quality control of anisodamine hydrobromide raw materials and preparations, and improves the drug safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the liquid phase chromatogram of NDSRI;

[0022] Figure 2-a and Figure 2-b and Figure 2-c are the NDSRI mass spectrometry diagrams;

[0023] Figure 3 is the NDSRI hydrogen spectrum diagram;

[0024] Figure 4 is the NDSRI carbon spectrum diagram. Specific Embodiments

[0025] The present invention provides an N-norhyoscyamine nitrosamine impurity and its synthesis method. Those skilled in the art can draw on the content of this article and appropriately modify the process parameters to achieve it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art, and they all fall within the protection scope of the present invention. The methods and applications of the present invention have been described through preferred embodiments, and those skilled in the art can obviously make changes or appropriate alterations and combinations to the methods and applications herein without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0026] This patent uses N-norhyoscyamine as the starting material, obtains NDSRI through synthesis reaction and purification, and clarifies its chemical structure through structural confirmation. Its chemical name is 6-hydroxy-8-nitroso-8-azabicyclo[3.2.1]oct-3-yl (S)-3-hydroxy-2-phenylpropionate.

[0027] The present invention provides an N-norhyoscyamine nitrosamine impurity with the structure of formula (I),

[0028]

[0029] The present invention provides a method for preparing an N-norhyoscyamine nitrosamine impurity with the structure of formula (I), which is characterized by including:

[0030] A) Mix and react anisodamine hydrobromide, copper acetate, ammonium persulfate and a solvent, concentrate under reduced pressure, and purify by reverse-phase silica gel column after extraction to obtain N-norhyoscyamine;

[0031] B) React N-norhyoscyamine with sodium nitrite in the presence of a solvent and an acid, and then obtain it through extraction, filtration, and concentration.

[0032] The method for preparing an N-norhyoscyamine nitrosamine impurity with the structure of formula (I) provided by the present invention first dissolves anisodamine hydrobromide in a solvent, and then adds copper acetate and ammonium persulfate and stirs for reaction.

[0033] In some specific embodiments, the solvent in step A) is 40% acetonitrile;

[0034] In some specific embodiments, the molar ratio of anisodamine hydrobromide, copper acetate, and ammonium persulfate is 1:(1.0 - 5.0):(1.0 - 5.0)3.

[0035] In some specific embodiments, the temperature of the reaction in step A) is room temperature, which can be 25 - 35 °C, and the reaction time is 20 - 24 h; preferably 24 h.

[0036] After the reaction is completed, acetonitrile is removed by concentration under reduced pressure at 60 °C, the pH is adjusted to 9.5 with 5% NaOH solution, and then extracted with dichloromethane. The extract is extracted with 2 volumes of 10% sulfuric acid. The pH of the aqueous phase extract is adjusted to 4.0 - 6.0, and then purified by reverse-phase silica gel column.

[0037] In some specific embodiments, the elution conditions for the reverse-phase silica gel column purification in step A) are as follows: from 0 to 45 min, 0.1% phosphoric acid solution is used as the mobile phase; from 45 to 60 min, 0.1% phosphoric acid solution:acetonitrile = 20:80 is used as the mobile phase for elution.

[0038] In the present invention, after elution, the pH is adjusted to 9.5 with 5% NaOH solution, then extracted with dichloromethane, the lower organic phase is collected, the extracts are combined, dichloromethane is removed by concentration under reduced pressure, dissolved in acetone at 60 °C, cooled and crystallized at 5 - 10 °C, filtered, and the filter cake is dried at 50 °C to obtain N-desmethyl anisodamine.

[0039] Among them, the extraction with dichloromethane is preferably carried out 4 times with 1 volume of dichloromethane.

[0040] N-desmethyl anisodamine and sodium nitrite are reacted in the presence of a solvent and an acid.

[0041] In some specific embodiments, the molar ratio of N-desmethyl anisodamine to sodium nitrite in step B) is 1:1 - 1:5.

[0042] The solvent is dichloromethane, and the acid is hydrochloric acid or formic acid; the addition amount of the acid is 0.5 - 5 times that of N-desmethyl anisodamine (volume-mass ratio, that is, 0.5 - 5 ml of acid is added to 1 g of N-desmethyl anisodamine); the addition amount of dichloromethane is 5 - 300 times that of N-desmethyl anisodamine (volume-mass ratio, that is, 5 - 300 ml of dichloromethane is added to 1 g of N-desmethyl anisodamine).

[0043] In some specific embodiments, the temperature of the reaction in step B) is 25 - 35 °C, and the reaction time is 3 - 4 h

[0044] In a specific embodiment, the temperature of the reaction in step B) is 25 - 35 °C, and the reaction time is 4 h.

[0045]

[0046] Then, through extraction, filtration, and concentration, it can be obtained.

[0047] In some specific embodiments, the extraction described in step B) is to add 1% sodium hydroxide solution to adjust the pH to 10 - 11, extract with dichloromethane, and combine the extraction solutions.

[0048] The dehydration in the present invention is carried out using anhydrous sodium sulfate; the concentration is carried out under reduced pressure at 40°C.

[0049] Specifically, it includes: adding a small amount of anhydrous sodium sulfate to the extraction solution until the solution becomes clear, stirring for dehydration for 10 min, filtering to obtain a filtrate. The filtrate is concentrated under reduced pressure at 40°C until no solvent distills out to obtain NDSRI.

[0050] The present invention provides a method for preparing N - desmethyl anisodamine nitrosamine impurity with the structure of formula (I), which is characterized by including: A) mixing hyoscyamine hydrobromide, copper acetate, ammonium persulfate, and a solvent for reaction, concentrating under reduced pressure, purifying by reverse - phase silica gel column after extraction to obtain N - desmethyl anisodamine; B) reacting N - desmethyl anisodamine with sodium nitrite in the presence of a solvent and an acid, and then through extraction, filtration, and concentration, it can be obtained. This patent provides a method for preparing NDSRI, provides a reference substance for the impurity research of hyoscyamine hydrobromide raw materials and preparations, is beneficial to improving the quality control of hyoscyamine hydrobromide raw materials and preparations, and enhancing the drug safety. It can also provide a reference substance for the impurity research of hyoscyamine hydrobromide raw materials and preparations.

[0051] It should be understood that the expression "one or more of..." individually includes each of the objects recited after the expression and various different combinations of two or more of the recited objects, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited objects should be understood to have the same meaning, unless otherwise understood from the context.

[0052] The terms "comprising", "having", or "containing", including the use of their grammatical synonyms, should generally be understood as open - ended and non - restrictive, for example, not excluding other unrecited elements or steps, unless otherwise specifically stated or otherwise understood from the context.

[0053] In this application, the term "and / or" describes the associated relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B can be singular or plural.

[0054] It should be understood that as long as the present invention is still operable, the order of steps or the order of performing certain actions is not important. In addition, two or more steps or actions can be carried out simultaneously.

[0055] The use of any and all examples or exemplary language, such as "for example" or "including", in this document is merely intended to better illustrate the present invention and does not limit the scope of the present invention unless a claim is made. No language in this specification should be construed as indicating that any unclaimed element is essential for the practice of the present invention.

[0056] In addition, the numerical ranges and parameters used to define the present invention are approximate values. The relevant numerical values in the specific embodiments have been presented as precisely as possible herein. However, any numerical value inherently and inevitably contains standard deviations resulting from individual testing methods. Therefore, unless otherwise clearly stated, it should be understood that all ranges, quantities, numerical values, and percentages used in this disclosure are modified by "about". Herein, "about" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific numerical value or range.

[0057] It should be understood that in various embodiments of the present application, the magnitude of the serial numbers of the above processes does not imply the order of execution. Some or all of the steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0058] Some cases are described in the embodiments and comparative examples of the present invention, in which the embodiments demonstrate certain implementation manners of the present invention. However, this does not mean that the effects of the present invention can only be achieved in these cases.

[0059] To further illustrate the present invention, a detailed description is given below of an N-norhyoscyamine nitrosamine impurity and its synthesis method provided by the present invention in combination with embodiments.

[0060] Example 1

[0061] 1. Preparation of N-norhyoscyamine

[0062] Take anisodamine hydrobromide and dissolve it in 10 times the volume of 40% acetonitrile. Add 2 molar equivalents of copper acetate and 3 molar equivalents of ammonium persulfate based on anisodamine hydrobromide. Stir and react at room temperature for 24 h. After the reaction is completed, concentrate under reduced pressure at 60 °C to remove acetonitrile. Adjust the pH to 9.5 with 5% NaOH solution, extract with dichloromethane, and extract the extract with 2 times the volume of 10% sulfuric acid. Adjust the pH of the aqueous phase extract to 4.0 - 6.0, and purify it on a reverse-phase silica gel column. Elution method:

[0063]

[0064]

[0065] After collecting the target substance, it was concentrated under reduced pressure at 80 °C. The pH was adjusted to 9.5 with 5% NaOH solution, and it was extracted 4 times with 1 volume of dichloromethane. The lower organic phase was collected, and the extraction solutions were combined. Dichloromethane was removed by concentration under reduced pressure. 5 volumes of acetone were added and dissolved at 60 °C, and then cooled and crystallized at 5 - 10 °C. It was filtered, and the filter cake was dried at 50 °C to obtain N-desmethylanisodamine.

[0066] 2. Synthesis

[0067] Weighed 1.00 g of N-desmethylanisodamine and 1.37 g of sodium nitrite into a 500 ml flask, added 200 ml of dichloromethane to dissolve, and then added 1 ml of hydrochloric acid. The reaction was stirred at room temperature for 4 hours.

[0068]

[0069] NDSRI Synthesis Equation Diagram

[0070] 3. Extraction

[0071] 30 ml of 1% sodium hydroxide solution was added to the reaction solution to adjust the pH to 10 - 11, and it was extracted with 3 volumes of dichloromethane. The extraction solutions were combined.

[0072] 4. Dehydration Filtration, Concentration

[0073] A small amount of anhydrous sodium sulfate was added to the extraction solution until the solution became clear, and it was stirred for dehydration for 10 min and then filtered to obtain the filtrate. The filtrate was concentrated under reduced pressure at 40 °C until no solvent was distilled out, and 0.96 g of NDSRI was obtained.

[0074] The yield was 0.96%, and the HPLC purity was 95.3%. The HPLC chromatogram is shown in the appendix Figure 1 .

[0075] 5. Structure Confirmation

[0076] Mass Spectrometry: The theoretical molecular weight of NDSRI is 320.35, and the measured molecular ion peaks are m / z 321.2 [M+1] and m / z 322.3 [M+2], which are consistent with the theoretical molecular weight. See the appendix Figure 2-a , Figure 2-b and Figure 2-c ; Figure 2-a , Figure 2-b and Figure 2-c are the mass spectrometry diagrams of NDSRI, where Figure 2-a , 2-b are the chromatograms, Figure 2-c is the full-scan mass spectrometry diagram;

[0077] 1 1H-NMR Spectrum: 11H NMR (400 MHz, Methanol-d4) δ = 1.095–1.201 (m, 1H), 1.343–1.454 (d, J = 8.2, 0H), 1.607–1.751 (m, 1H), 1.869–2.068 (m, 2H), 2.073–2.207 (m, 2H), 2.206–2.294 (t, J = 3.9, 1H), 3.257–3.350 (p, J = 1.6, 1H), 3.519–3.637 (q, J = 7.0, 0H), 3.725–3.893 (m, 2H), 4.090–4.231 (m, 1H), 4.483–4.664 (m, 2H), 4.722–4.815 (s, 0H), 4.896–5.072 (dd, J = 6.2, 39.5, 2H), 7.195–7.454 (m, 5H). See attachment Figure 3 。

[0078] 13 13C NMR (101 MHz, Methanol-d4) δ = 34.046–34.246, 35.380–35.578, 37.454–37.742, 38.420–38.752, 38.763–39.065, 39.065–39.288, 51.070–51.310, 55.889–56.130, 58.572–58.852, 60.652–60.890, 64.390–64.834 (d, J = 2.3), 67.497–67.696, 68.392–68.633, 72.708–73.099 (d, J = 5.8), 128.858–129.113 (d, J = 1.3), 129.172–129.372, 129.964–130.396 (d, J = 1.8), 137.104–137.325 (d, J = 2.3), 172.796–173.036. See attachment Figure 4 。

[0079] Example 2:

[0080] (1) Synthesis

[0081] Weigh 1.00 g of N-norhyoscyamine and 1.37 g of sodium nitrite into a 500 ml flask, add 200 ml of acetone to dissolve, and then add 1 ml of formic acid. Stir the reaction at room temperature for 4 hours.

[0082]

[0083] NDSRI Synthesis Equation Diagram

[0084] (2) Extraction

[0085] The reaction solution was adjusted to pH 10.5 with 1% sodium hydroxide solution and extracted with 3 times dichloromethane, and the extraction solutions were combined.

[0086] (3) Dehydration, filtration and concentration

[0087] A small amount of anhydrous sodium sulfate was added to the extraction solution until the solution was clear, and dehydrated by stirring for 10 min, then filtered to obtain the filtrate. The filtrate was concentrated under reduced pressure at 40 °C until no solvent was distilled out, and 1.12 g of N-norhyoscyamine nitrosamine impurity was obtained. The yield was 0.86%, and the HPLC purity was 95.6%.

[0088] Comparative Example 1

[0089] Preparation of N-norhyoscyamine

[0090] Hyoscyamine hydrobromide was dissolved in 10 times volume of 40% acetonitrile, and copper acetate in 2 times molar amount and peracetic acid in 2 times molar amount of hyoscyamine hydrobromide were added, and the reaction was stirred at room temperature for more than 24 h, and the target product was not obtained.

[0091] Synthesis of NDSRI

[0092] 1.00 g of N-norhyoscyamine and 1.37 g of sodium nitrite were weighed into a 500 ml flask, dissolved with 200 ml of water, then 1 ml of formic acid was added, and the reaction was stirred at room temperature for 24 hours, and the target product was not obtained.

[0093] The above are only the preferred embodiments of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An N-norhyoscyamine nitrosamine impurity of the formula (I) structure, 2. A method for preparing the N-norhyoscyamine nitrosamine impurity of the structure of formula (I), characterized in that, comprising: A) Mixing and reacting anisodamine hydrobromide, copper acetate, ammonium persulfate and a solvent, concentrating under reduced pressure, extracting, and purifying using a reverse-phase silica gel column to obtain N-norhyoscyamine; B) Reacting N-norhyoscyamine with sodium nitrite in the presence of a solvent and an acid, followed by extraction, filtration, and concentration to obtain the product.

3. The method according to claim 1, wherein The solvent in step A) is 40% acetonitrile; the molar ratio of anisodamine hydrobromide, copper acetate, and ammonium persulfate is 1:2:

3.

4. The method according to claim 1, wherein The temperature of the reaction in step A) is 25 - 35 °C, and the reaction time is 20 - 24 h.

5. The method according to claim 1, wherein The extraction in step A) includes: Adjusting the pH to 9.5 with 5% NaOH solution, extracting with dichloromethane, extracting the extract with 2 volumes of 10% sulfuric acid, and adjusting the pH of the aqueous phase extract to 4.0 - 6.

0.

6. The method according to claim 1, characterized in that, The elution conditions for the purification using the reverse-phase silica gel column in step A) are: from 0 to 45 min, using 0.1% phosphoric acid solution as the mobile phase; from 45 to 60 min, eluting with a mobile phase of 0.1% phosphoric acid solution:acetonitrile = 20:

80.

7. The method according to claim 6, wherein After elution, adjust the pH to 9.5 with 5% NaOH solution, then extract with dichloromethane, collect the lower organic phase, combine the extracts, concentrate under reduced pressure to remove dichloromethane, dissolve in acetone at 60 °C, cool and crystallize at 5 - 10 °C, filter, and dry the filter cake at 50 °C to obtain N-norhyoscyamine.

8. The method according to claim 1, wherein The molar ratio of N-norhyoscyamine to sodium nitrite in step B) is 1:1 - 1:5; The solvent is dichloromethane, and the acid is hydrochloric acid or formic acid; the addition amount of the acid is 0.5 - 5 times (volume-mass ratio, i.e., 0.5 - 5 ml of acid is added to 1 g of N-norhyoscyamine); the addition amount of dichloromethane is 5 - 300 times (volume-mass ratio, i.e., 5 - 300 ml of dichloromethane is added to 1 g of N-norhyoscyamine).

9. The method according to claim 1, wherein The temperature of the reaction in step B) is 25 - 35 °C, and the reaction time is 3 - 4 h.

10. The method according to claim 1, wherein The extraction in step B) is to adjust the pH to 10 - 11 by adding 1% sodium hydroxide solution and extract with dichloromethane; The dehydration is carried out using anhydrous sodium sulfate; the concentration is carried out under reduced pressure at 40 °C.

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