Method for preparing vincristine impurity

Abstract

The invention belongs to the technical field of pharmaceutical analysis, and particularly relates to a method for preparing vincristine impurities. The method specifically comprises the following steps: by taking vinblastine as a raw material, activating hydroxyl, performing elimination reaction, and performing epoxidation reaction with organic peracid to obtain an impurity F; oxidizing nitrogen methyl of the impurity F to obtain an impurity G; the impurity F and the impurity G provided by the invention are simple in preparation process, convenient to operate and relatively high in reaction yield, can be used as impurity standard substances, and provide a detection and judgment basis for subsequent research or monitoring of vincristine related substances or impurities.

Description

Technical Field

[0001] The invention belongs to the technical field of drug analysis, and particularly relates to a method for preparing vincristine impurities. Background Art

[0002] Vincristine (Vincristine, molecular formula is C 46 H 56 N4O 10 ), CAS number is 57-22-7.

[0003] The European Pharmacopoeia records 8 impurities in the synthesis process of vincristine, including intermediate impurities, isomer impurities, degradation impurities, etc. The structural formulas of impurity F and impurity G are as follows: ; . Summary of the invention

[0004] In view of the above technical problems, the present invention provides a solution, a method for preparing vincristine EP (recorded in the European Pharmacopoeia) impurity F and EP impurity G.

[0005] Specifically, the present invention provides the following technical solutions: Vincristine impurities include impurity F and impurity G.

[0006] (I) Method for preparing impurities of vincristine, route for preparing impurity F: .

[0007] In one embodiment, the preparation of impurity F comprises the following steps: Vinblastine is dissolved in DMF (N,N-dimethylformamide), and a reagent is added to activate the hydroxyl group and an elimination reaction occurs to obtain an intermediate product, namely compound 1; Compound 1 undergoes epoxidation reaction with a peracid reagent to obtain impurity F.

[0008] In one embodiment, in the preparation of impurity F, the reagent for activating the hydroxyl group includes one or more of thionyl chloride, methanesulfonyl chloride, and p-toluenesulfonyl chloride, preferably thionyl chloride.

[0009] In one embodiment, the preparation includes: dissolving vinblastine, replacing with nitrogen for protection, cooling to -20°C, adding a reagent for activating hydroxyl groups at a temperature of -20°C to -15°C, removing the cold bath, slowly returning to 20 to 30°C for reaction, adjusting the pH, standing for separation, extracting, washing, and concentrating under reduced pressure to dryness to obtain compound 1.

[0010] In one embodiment, in the preparation of impurity F, the peracid reagent includes an organic peracid, and the organic peracid is prepared in situ using a carboxylic acid and a peroxide.

[0011] In one embodiment, in the preparation of impurity F, the carboxylic acid includes one or more of acetic acid, trifluoroacetic acid, trichloroacetic acid, benzoic acid, and o-nitrobenzoic acid, preferably acetic acid or trifluoroacetic acid.

[0012] In one embodiment, in the preparation of impurity F, the peroxide includes one or more of hydrogen peroxide, potassium persulfate, benzoyl peroxide, and tert-butyl hydroperoxide. Preferably, tert-butyl hydroperoxide is used.

[0013] In one embodiment, the epoxidation reaction temperature is 20-30°C.

[0014] (II) Route for preparing impurity G: .

[0015] In one embodiment, the preparation of impurity G includes the following steps: impurity F is subjected to an oxidation reaction to obtain impurity G.

[0016] In one embodiment, in the preparation of impurity G, the oxidizing reagent of the oxidation reaction is selected from one or more of chromyl chloride, a mixture of Jones reagent and acetic anhydride, and pyridinium chlorochromate (PCC), and preferably a mixture of Jones reagent and acetic anhydride is used.

[0017] In one embodiment, in the oxidation reaction, after adding the oxidizing agent, the temperature is lowered under nitrogen protection, and the oxidizing agent is added dropwise at a temperature of -80°C to -70°C, and the reaction is kept warm after the addition; the temperature is controlled and adjusted, extraction is performed, the liquid is allowed to stand for separation, concentration is performed, and impurity G is obtained by separation and purification.

[0018] Furthermore, in the oxidation reaction, after adding the oxidizing agent, the temperature is lowered to -80°C under nitrogen protection, and the oxidizing agent is added dropwise at a temperature of -80°C to -70°C, and the temperature is kept for reaction after the addition. The concentrated ammonia water is slowly added to the reaction solution at a temperature below -40°C, and the sodium sulfite aqueous solution is continued to be added dropwise after stirring. After the addition, the cold bath is removed and the temperature is slowly returned to 20-30°C. Extraction is performed and the liquid is separated by standing. The organic phase is concentrated under reduced pressure to dryness and then purified by preparative liquid phase separation to obtain impurity G.

[0019] Different from the prior art, the advantages of the present invention are: The present invention adopts corresponding raw materials to prepare impurity F and impurity G, has a simple synthesis process, is easy to operate, and has a high reaction yield, thus providing a detection and judgment basis for subsequent research or monitoring of vincristine raw materials and related substances or impurities. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0021] In the attached picture: Figure 1 It is the nuclear magnetic analysis diagram of impurity F in the present invention; Figure 2 It is the NMR analysis diagram of impurity G in the present invention. DETAILED DESCRIPTION

[0022] The present invention is described in detail below in conjunction with various embodiments, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0023] The invention provides a method for preparing vincristine impurities. The vincristine impurities include impurities F and impurities G.

[0024] Example 1 Preparation of compound 1: Dissolve 1.0 g of Vinblastine in 13 mL of DMF, replace with nitrogen, cool to -20 °C, add thionyl chloride dropwise at -20 °C~-15 °C, remove the cold bath, slowly return to 20~30 °C and react for 2 hours. Under stirring, add the reaction solution to 100 mL of saturated saline, and adjust the pH to 8.0 with concentrated ammonia. Let stand and separate, and extract the aqueous phase with 100 mL of dichloromethane. Combine the organic phases, wash twice with purified water, and concentrate under reduced pressure to obtain 1.07 g of the product as a brown solid.

[0025] Example 2 Preparation of impurity F: Dissolve 500 mg of compound 1 and 40 mL of tetrahydrofuran in a 100 mL single-mouth bottle, add 4 mL of 1% trifluoroacetic acid aqueous solution and 4 mL of 70% tert-butyl hydroperoxide aqueous solution in turn, and stir at 20-30 ° C for 48 hours. Add the reaction solution to 100 mL of saturated saline and adjust the pH to 8.0 with concentrated ammonia. Let stand and separate the liquids, and extract the aqueous phase with 100 mL of dichloromethane. Combine the organic phases, wash twice with purified water, and concentrate under reduced pressure to obtain 492 mg of crude product. The crude product was separated and purified by preparative liquid phase to obtain 162 mg of white solid product, HPLC purity 94.59%, MS (ESI): 808.91 [M+H] + . Reference Figure 1 .

[0026] Embodiment 3: Preparation of impurity G: Add 200 mg of impurity F and 30 mL of acetone to a 100 mL three-necked flask, add 4 mL of acetic anhydride with stirring, cool to -80 ° C under nitrogen protection, add 2 mL of Jones reagent at -80 ° C ~ -70 ° C, and keep warm for 1.5 hours. Control the temperature below -40 ° C and slowly add 40 mL of concentrated ammonia water to the reaction solution. After stirring for 10 minutes, continue to add 5% sodium sulfite aqueous solution. After the addition, remove the cold bath and slowly return to 20 ~ 30 ° C. Add 40 mL of dichloromethane and let stand to separate. After the organic phase is concentrated under reduced pressure, it is purified by preparative liquid separation to obtain 78 mg of the target white solid, HPLC purity 94.32%, MS (ESI): 822.78 [M + H] + . Reference Figure 2 .

[0027] In the foregoing, if not otherwise specified, all reagents used in the following examples are commercially available or can be synthesized with reference to existing literature or known methods, and the reaction or test conditions not listed are also conventional technical means that are easily available to those skilled in the art. The terms used in the present invention are commonly used in the art, and those skilled in the art can clearly understand their meanings, such as aqueous solutions, etc., and are not described one by one.

[0028] The above is only a preferred embodiment of the present invention, and does not limit the technical solution of the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing vincristine impurities, wherein the vincristine impurities include impurities F and impurities G, characterized in that: Route for preparing impurity F: ； Route for preparing impurity G: 。 2. The method for preparing vincristine impurities according to claim 1, characterized in that: The preparation of impurity F comprises the following steps: Vinblastine was dissolved in DMF, and reagents were added to activate the hydroxyl group and undergo elimination reaction to obtain compound 1; Compound 1 undergoes epoxidation reaction with a peracid reagent to obtain impurity F.

3. The method for preparing vincristine impurities according to claim 2, characterized in that: In the preparation of impurity F, the reagent for activating the hydroxyl group includes one or more of thionyl chloride, methanesulfonyl chloride, and p-toluenesulfonyl chloride; and the temperature of the epoxidation reaction is 20-30°C.

4. The method for preparing vincristine impurities according to claim 2, characterized in that: In the preparation of impurity F, the peracid reagent includes an organic peracid, and the organic peracid is prepared in situ using a carboxylic acid and a peroxide.

5. The method for preparing vincristine impurities according to claim 4, characterized in that: In the preparation of impurity F, the carboxylic acid includes one or more of acetic acid, trifluoroacetic acid, trichloroacetic acid, benzoic acid, and o-nitrobenzoic acid.

6. The method for preparing vincristine impurities according to claim 4, characterized in that: In the preparation of impurity F, the peroxide includes one or more of hydrogen peroxide, potassium persulfate, benzoyl peroxide, and tert-butyl hydroperoxide.

7. The method for preparing vincristine impurities according to claim 2, characterized in that: The preparation of impurity F also includes: dissolving vinblastine in DMF, replacing with nitrogen for protection, cooling to -20°C, adding a reagent for activating the hydroxyl group at a temperature of -20°C to -15°C, removing the cold bath, slowly returning to 20~30°C for reaction; adjusting the pH, standing and separating the liquids, extracting, washing, and concentrating under reduced pressure to dryness to obtain compound 1.

8. The method for preparing vincristine impurities according to claim 1, characterized in that: The preparation of impurity G comprises the following steps: impurity F is subjected to an oxidation reaction to obtain impurity G.

9. The method for preparing vincristine impurities according to claim 8, characterized in that: In the preparation of impurity G, the oxidizing reagent for the oxidation reaction includes one or more of chromyl chloride, a mixture of Jones reagent and acetic anhydride, and pyridinium chlorochromate.

10. The method for preparing vincristine impurities according to claim 8, characterized in that: In the oxidation reaction, after adding the oxidizing agent, the temperature is lowered under nitrogen protection, and the oxidizing agent is added dropwise at a temperature of -80°C to -70°C. After the addition is completed, the temperature is kept for reaction; the temperature is controlled and adjusted, extraction is performed, the liquid is allowed to stand for separation, concentration is performed, and impurity G is obtained by separation and purification.

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