Preparation method of propofol tenofovir lactoside impurity
By preparing high-purity propofol tenofovir lactose, the problem of risk of Melard reaction and lactose addition in existing tenofovir fumarate raw materials was solved, and the reliability of drug quality research was improved.
Patent Information
- Application Number
- CN202311815090.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-27
- Publication Date
- 2025-06-27
AI Technical Summary
The existing tenofovir fumarate raw materials contain primary amine structure and high lactose content, which is prone to Maillard reactions, increasing the risk of addition to lactose and affecting the quality of the drug.
A lactose-side of propofol tenofovir was prepared, and a high-purity lactose-side was obtained through the steps of lactose acetylation, silanization, condensation and hydrolysis, and the purity was greater than 95%.
The preparation of high-purity propofol tenofovir lactose is achieved, which solves the problem of the risk of Maillard reaction and lactose addition, and improves the reliability of drug quality research.
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Figure CN120209055A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of biomedicine, and particularly relates to the structure of lactoside of tenofovir alafenamide and its preparation method. Background Art
[0002] Tenofovir alafenamide fumarate (TAF) is a nucleic acid reverse transcriptase inhibitor and a prodrug of tenofovir. It was launched in the United States in 2001 for the treatment of HIV infection and chronic HBV infection. After oral administration, this product is rapidly converted into tenofovir, which is phosphorylated into tenofovir diphosphate under the action of cellular kinases. By competitively binding with the natural deoxyribose substrate, it inhibits viral polymerase and terminates DNA chain elongation after embedding into viral DNA, thereby inhibiting the activities of HIV and HBV.
[0003] Both TAF and tenofovir disoproxil fumarate (TDF), a commonly used drug for treating hepatitis B at present, are prodrugs of tenofovir. However, TAF can produce an antiviral effect equivalent to that of TDF with only one-tenth of the dose, thus greatly reducing the risks of nephrotoxicity and osteoporosis and having higher safety and tolerance.
[0004] The raw material of tenofovir disoproxil fumarate contains a primary amine structure, and the lactose content in the formulation is relatively high, which may cause Maillard reaction and increase the risk of adduct formation with lactose. The research on the quality of the drug requires the study of the impurities generated by the reaction of tenofovir and lactose. Summary of the Invention
[0005] The purpose of the present invention is to provide the structure of tenofovir alafenamide lactoside and its preparation and purification methods, with a purity greater than 95%. Compound 1 is used for the quality research work of tenofovir alafenamide fumarate.
[0006] Its structural formula:
[0007]
[0008] Molecular formula: C 33 H 49 N6O 15 P;
[0009] Molecular weight: 800.75.
[0010] The preparation method of the high-purity tenofovir lactoside provided by the present invention has a specific preparation route as shown in the appendix Figure 1 as follows. The preparation method includes the following steps:
[0011] (1) Lactose (Compound 2) is added with sodium acetate and acetic anhydride for acetylation to obtain the crude product of Compound 3;
[0012] (2) The crude product of Compound 3 is recrystallized with an alcohol solvent to obtain Compound 3;
[0013] (3) Tenofovir (Compound 4) is silylated with a silylating agent to obtain Compound 5;
[0014] (4) Compound 3 and Compound 5 are condensed under the action of a catalyst and then quenched to obtain a crude product of Compound 6;
[0015] (5) The crude product of Compound 6 is recrystallized to obtain Compound 6;
[0016] (6) Compound 6 is hydrolyzed under alkaline conditions to obtain a crude product of Compound 1;
[0017] (7) The crude product of Compound 1 is recrystallized to obtain Compound 1.
[0018] In Step 1, the reaction time and temperature are to react at 60°C - 65°C for 3 hours first, and then reflux for 2 hours.
[0019] In Step 2, the alcohol solvent is methanol or ethanol, preferably ethanol.
[0020] In Step 3, the silylating agent is hexamethyldisilazane, the solvent is toluene, the catalyst is ammonium sulfate, the reaction temperature is 110 ± 2°C, and the reaction time is 5 - 8 hours.
[0021] In Step 4, the condensation catalyst is anhydrous tin tetrachloride, and the quenching reagent is water and sodium bicarbonate. The reaction temperature is 0 - 5°C.
[0022] In Step 5, the recrystallization solvent is acetonitrile and toluene, and the solvent ratio is by volume. Acetonitrile: Toluene
[0023] = 1:4 - 1:10, preferably acetonitrile: toluene = 1:6.
[0024] In Step 6, the hydrolysis solution is ethanol and water, and the compounds under alkaline conditions are sodium hydroxide and potassium hydroxide, preferably potassium hydroxide.
[0025] In Step 7, the recrystallization solvent is ethyl acetate or isopropyl acetate, preferably ethyl acetate. Description of the Drawings
[0026] Appendix Figure 1 : Specific preparation route diagram of the present invention.
[0027] Appendix Figure 2 : Mass spectrometry diagram of lactoside of tenofovir alafenamide prepared in Example 1.
[0028] Appendix Figure 3 : 1H NMR spectrum diagram of lactoside of tenofovir alafenamide prepared in Example 1. Detailed Description of the Invention
[0029] The present invention relates to a method for preparing lactoside of tenofovir alafenamide. The specific implementation is as follows:
[0030] Example 1
[0031] ⑴: 10 g (29.21 mmol) of lactose, 7.79 g (58.42 mmol) of sodium acetate, 80 ml (850 mmol) of acetic anhydride. Heat to 60 - 65 °C and stir for 3 hours, then heat to reflux for 2 hours and cool. Add 80 ml of methanol and concentrate under reduced pressure to dryness. Add 200 ml of dichloromethane, wash twice with 100 ml of 5% sodium bicarbonate solution and twice with 100 ml of saturated brine. Dry over anhydrous sodium sulfate, filter, and concentrate under reduced pressure to dryness. Obtain 18.20 g of crude peracetyl lactose.
[0032] ⑵: 18.20 g of crude peracetyl lactose, add 73 ml of absolute ethanol, heat to 75 °C, stir until dissolved and clear, let stand for crystallization, cool to room temperature. Filter and dry in vacuo at 40 °C to obtain 14.20 g of peracetyl lactose (Compound 3), with a yield of 71.63%.
[0033] ⑶: 10 g (20.99 mmol) of tenofovir alafenamide (Compound 4), 60 ml of toluene, 3.39 g (21.00 mmol) of hexamethyldisilazane, 0.2 g of ammonium sulfate. Heat to 110 ± 2 °C until all solids are dissolved, about 5 - 8 hours. Concentrate under reduced pressure to dryness to obtain Compound 5, which is directly used for the next step.
[0034] ⑷: Add 120 ml of dichloromethane to the concentrate of Compound 4, 14.20 g (20.93 mmol) of peracetyl lactose (Compound 3), cool, and dropwise add a mixture of 6.56 g (25.20 mmol) of anhydrous stannic chloride and 4 ml of dichloromethane at an internal temperature of -5 to 0 °C. After dropping, stir at 0 - 5 °C for 2 hours. First add 1 g of sodium bicarbonate and 4 g of water, then add 11 g of sodium bicarbonate in portions. After adding, stir at room temperature for 3 hours. Filter, and wash the filter cake with 40 ml of dichloromethane. Wash the filtrate twice with 20 ml of 4% sodium bicarbonate and once with 20 ml of water. Dry over anhydrous sodium sulfate. Filter and concentrate to dryness under reduced pressure.
[0035] ⑸: Add 80 ml of acetonitrile, heat to 65 - 75 °C, stir until dissolved and clear, dropwise add 480 ml of toluene, and stir for crystallization at 10 - 15 °C for 3 hours. Filter and wash the filter cake with a mixture of 20 ml of acetonitrile and 120 ml of toluene.
[0036] Dry in vacuo at 50 °C. Obtain 15.05 g of Compound 6. The yield is 65.65%.
[0037] ⑹: 15.05 g (13.74 mmol) of compound 6, 75 ml of absolute ethanol. A solution of 16.19 g (288.59 mmol) of potassium hydroxide and 60 ml of water was added dropwise at -5°C to 0°C. After the addition was complete, the mixture was stirred at a constant temperature for one hour. A mixture of 28.47 g (288.59 mmol) of concentrated hydrochloric acid and 200 ml of water was added dropwise. The mixture was extracted twice with 300 ml * 2 of dichloromethane. The organic phases were combined, washed twice with 75 ml * 2 of saturated brine, dried over anhydrous sodium sulfate for 4 hours, filtered, and concentrated under reduced pressure to dryness. 30 ml of ethyl acetate was added, and the mixture was heated to 65°C to dissolve, cooled to room temperature to crystallize, filtered, and dried in vacuo at 35°C to obtain 5.30 g. The yield was 48.16%.
[0038] Example 2
[0039] ⑴: 10 g (29.21 mmol) of lactose, 7.79 g (58.42 mmol) of sodium acetate, 80 ml (850 mmol) of acetic anhydride. The mixture was heated to 60 - 65°C and stirred for 3 hours, then heated to reflux for 2 hours and cooled. 80 ml of methanol was added, and the mixture was concentrated under reduced pressure to dryness. 200 ml of dichloromethane was added, and the mixture was washed twice with 100 ml of 5% sodium bicarbonate solution and twice with 100 ml of saturated brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to dryness. 18.20 g of crude peracetyl lactose was obtained.
[0040] ⑵: 18.20 g of crude peracetyl lactose was added with 73 ml of absolute methanol, heated to 60°C, stirred until clear, allowed to stand for crystallization, and cooled to room temperature. Filtered and dried in vacuo at 40°C to obtain 9.51 g of peracetyl lactose (compound 3), with a yield of 47.98%.
[0041] ⑶: 6.69 g (14.04 mmol) of tenofovir alafenamide (compound 4), 40 ml of toluene, 2.27 g (14.06 mmol) of hexamethyldisilazane, 0.13 g of ammonium sulfate. The mixture was heated to 110 ± 2°C until all the solids were dissolved, about 5 - 8 hours. Concentrated under reduced pressure to dryness to obtain compound 5, which was directly used in the next step.
[0042] ⑷: 80 ml of dichloromethane was added to the concentrate of compound 4, 9.51 g (14.01 mmol) of peracetyl lactose (compound 3). The mixture was cooled, and a mixture of 4.39 g (16.85 mmol) of anhydrous stannic chloride and 3 ml of dichloromethane was added dropwise at an internal temperature of -5 to 0°C. After the addition was complete, the mixture was stirred at a constant temperature of 0°C to 5°C for 2 hours. First, 0.7 g of sodium bicarbonate and 2.7 g of water were added, and then 7.5 g of sodium bicarbonate was added in portions. After the addition was complete, the mixture was stirred at room temperature for 3 hours. Filtered, and the filter cake was washed with 30 ml of dichloromethane. The filtrate was washed twice with 12 ml × 2 of 4% sodium bicarbonate and 12 ml of water. Dried over anhydrous sodium sulfate. Filtered and concentrated to dryness under reduced pressure.
[0043] ⑸: Add 60 ml of acetonitrile, heat to 65 °C - 75 °C, stir until dissolved clearly, add dropwise 360 ml of toluene, stir and crystallize at 10 °C - 15 °C for 3 hours. Filter, wash the filter cake with a mixed solution of 15 ml of acetonitrile and 90 ml of toluene. Dry under vacuum at 50 °C. Obtain 10.11 g of the compound. The yield is 65.88%.
[0044] ⑹: 10.11 g (9.23 mmol) of the compound, 50 ml of absolute ethanol, add dropwise a solution of 10.87 g (193.76 mmol) of potassium hydroxide and 40 ml of water at -5 °C - 0 °C, keep stirring for one hour after the addition is completed. Add dropwise a mixed solution of 12.75 g (129.17 mmol) of concentrated hydrochloric acid and 120 ml of water. Extract twice with 200 ml * 2 of dichloromethane, combine the organic phases, wash twice with 50 ml * 2 of saturated brine, dry with anhydrous sodium sulfate for 4 hours, filter, and concentrate under reduced pressure to dryness. Add 20 ml of isopropyl acetate, heat to dissolve at 65 °C, cool to room temperature to crystallize, filter, dry under vacuum at 35 °C, and obtain 3.77 g. The yield is 51%.
Claims
1. A compound of Structural Formula 1 The Chinese name is: (S)-isopropyl 2-{[(S)-phenoxy({[(R)-1-(6-{[(3S,4R,5R)-3,5,6-trihydroxy-2-oxo-4-{[(2S,3R,4S,5R,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl]oxy}hexyl]amino}-9H-purin-9-yl)propan-2-yl]oxy}methyl)phosphoryl]amino}propionate, abbreviated as tenofovir alafenamide lactoside, which is used in the quality research of tenofovir alafenamide as an impurity reference substance.
2. Preparation method of Compound 1, characterized in that: Lactose (Compound 2) is acetylated to obtain octaacetyl lactose (Compound 3); tenofovir alafenamide is silylated to obtain silylated tenofovir alafenamide (Compound 5); Compound 3 and Compound 5 are condensed to obtain Compound 6; Compound 6 is hydrolyzed to obtain Compound 1.
3. The preparation method of compound 1 according to claim 2, characterized in that, In the step of preparing Compound 3, the acetylation reagent is acetic anhydride and sodium acetate. The esterification reaction temperature is first reacted at 60°C - 65°C for 3 hours, then refluxed for 2 hours. The recrystallization solvent is methanol or ethanol.
4. The preparation method of compound 1 according to claim 2, characterized in that, In the step of preparing Compound 5, the silylating reagent used is hexamethyldisilazane, and the catalyst is ammonium sulfate. The reaction temperature is 110 ± 2°C.
5. The preparation method of compound 1 according to claim 2, characterized in that, In the step of preparing Compound 6, the condensation catalyst is anhydrous tin tetrachloride, and the quenching reaction reagent is water and sodium bicarbonate. The recrystallization solvent of Compound 6 is acetonitrile and toluene.
6. The preparation method of compound 1 according to claim 2, characterized in that, In the step of preparing Compound 1, the hydrolysis solvent is ethanol and water, the base used for hydrolysis is sodium hydroxide or potassium hydroxide, and the recrystallization solvent is ethyl acetate or isopropyl acetate.