A method for the synthesis of alkyl derivatives of the hydroxyl group at position 40 of rapamycin

Abstract

The application discloses a kind of rapamycin 40-position hydroxyl alkyl synthesis method, belong to the technical field of drug synthesis.The method is: in inert gas atmosphere, rapamycin is sequentially added into microwave reaction tube, molecular sieve and additive, additive is triphenyl phosphine oxide, tri (4-fluorophenyl) phosphine oxide, tri (4-methoxyphenyl) phosphine oxide, tricyclohexyl phosphine oxide, triphenyl phosphine sulfide, triphenyl phosphine selenide or hexamethylphosphorus triamide;Subsequently, alkylating agent, base and organic solvent are added, sealed, reacted in microwave reaction instrument, cooled, filtered, washed, dried, filtered, purified, to obtain the alkylated product of rapamycin 40-position hydroxyl group.The method compared with the existing rapamycin 40-position hydroxyl group alkyl modification method, simple operation, low cost, short reaction time, less impurities, easy separation, higher yield, up to 79.1%, suitable for industrial production, can provide new ideas for synthesis and development of rapamycin derivatives such as everolimus.

Description

Technical Field

[0001] This invention belongs to the field of drug synthesis technology, specifically relating to an alkylation synthesis method for the 40-hydroxyl group of rapamycin. Background Technology

[0002] Rapamycin (also known as sirolimus), isolated from plant and soil specimens collected on Easter Island by the Ajester Laboratory, is a natural product produced by Streptomyces (J. Antibiotics 1975, 28, 721–726; J. Antibiotics 1975, 28, 727–732). As the first mTOR inhibitor, rapamycin is used as an immunosuppressant and stent coating agent for organ transplant rejection (Med. Res. Rev. 1994, 14, 1–22) and for treating coronary artery restenosis. In the early 1990s, scientists discovered that rapamycin also has antitumor effects (Cancer Treat. Rev. 1981, 8, 63–87; J. Antibiotics 1984, 37, 1231–1237). Currently, research on rapamycin for the treatment of cancers such as leukemia, kidney cancer, liver cancer, breast cancer, non-small cell lung cancer, and bladder cancer is in the clinical trial stage. The antitumor activity of rapamycin has attracted the attention of pharmaceutical researchers worldwide, leading to localized modifications and alterations to its structure, resulting in a series of valuable derivatives. For example, Temsirolimus, developed by Wyeth Pharmaceuticals, has been approved by the FDA for the treatment of advanced kidney cancer; Everolimus, developed by Novartis, has been approved by the FDA for the treatment of advanced kidney cancer and breast cancer. In summary, modifications and alterations to the structure of rapamycin have successfully led to the development of several anticancer drugs with satisfactory clinical results. Therefore, further structural modifications of rapamycin to obtain rapamycin-based mTOR-targeted antitumor drugs with enhanced antitumor activity have significant application value.

[0003] Currently, there are three main types of alkylation modification of the 40-hydroxyl group in rapamycin:

[0004] Method 1: Patents US5665772 and WO9409010 reported an earlier method for the alkylation of rapamycin to synthesize everolimus. In this method, rapamycin is reacted with 2-(tert-butyldimethylsiloxy)ethyl trifluoromethanesulfonate in toluene in the presence of 2,6-dimethylpyridine to give intermediate A (synthetic route below). However, the yield of this alkylation reaction is very low, only 5-15%, with most of the starting material remaining unconverted.

[0005]

[0006] Method 2: The methods disclosed in patents CN201010017955 and CN201511030109 use ethyl trifluoromethanesulfonate-2-(tert-butyldiphenylsilyl)ethyl trifluoromethanesulfonate instead of ethyl trifluoromethanesulfonate-2-(tert-butyldimethylsilyl)ethyl trifluoromethanesulfonate to prepare intermediate product B by improving the alkylation reaction conditions (synthetic route as follows). Although this alkylation reaction can achieve a yield of 55-65%, the reaction requires three repeated slow additions of alkali and alkylating reagent, which is cumbersome, time-consuming, and unsuitable for industrial scale-up production.

[0007]

[0008] Method 3: Patents CN102268015A, CN103848849A, and CN105254646A report that rapamycin or its derivatives are used as raw materials. The reaction with trifluoromethanesulfonic anhydride activates the 40-hydroxyl group to obtain intermediate C, which then reacts with ethylene glycol containing a protecting group to obtain the alkylated product D (synthetic route below). However, this process requires rapamycin to undergo three steps to obtain its alkylated product, resulting in numerous steps, high losses, difficulty in separation, and high costs. Furthermore, the preparation process for obtaining the ethylene glycol with the protecting group is complex, with low yields, making it unsuitable for industrial production.

[0009]

[0010] In summary, current methods for the alkylation synthesis of the 40-hydroxyl group in rapamycin suffer from problems such as low yield, numerous byproducts, many impurities, difficulty in separation, and long reaction times, which are unfavorable for industrial-scale production. Therefore, providing a novel alkylation synthesis method for the 40-hydroxyl group in rapamycin would be of great application value, offering a simple, efficient, low-cost, and high-quality process for the synthesis of rapamycin derivatives such as everolimus. Summary of the Invention

[0011] In order to overcome the shortcomings of the prior art, the present invention aims to provide a method for the alkylation synthesis of the 40-hydroxyl group of rapamycin, which solves the problems of low yield, many impurities, difficulty in separation, long reaction time and unfavorable industrial scale-up in the alkylation process of rapamycin.

[0012] To achieve the above objectives, the present invention employs the following technical solution:

[0013] This invention discloses a method for synthesizing the alkylation of the 40-hydroxyl group of rapamycin. In an inert gas atmosphere, rapamycin and an additive are added sequentially, followed by the addition of an alkylating agent, a base and an organic solvent. The reaction is carried out under microwave conditions, followed by filtration, washing, drying, filtration and separation and purification to obtain the alkylated product of the 40-hydroxyl group of rapamycin.

[0014] The additive is triphenylphosphine oxide, tri(4-fluorophenyl)phosphine oxide, tri(4-methoxyphenyl)phosphine oxide, tricyclohexylphosphine oxide, triphenylphosphine sulfide, triphenylphosphine selenide, or hexamethylphosphine triamine.

[0015] Preferably, the amount of additive added is 1 to 20 molar equivalents of rapamycin; the amount of alkylating agent added is 1 to 20 molar equivalents of rapamycin; and the amount of base added is 1 to 20 molar equivalents of rapamycin.

[0016] Preferably, the alkylating agent is ethyl trifluoromethanesulfonate-2-[tert-butyldimethylsilyl]trifluoromethanesulfonate-2-(propynyl)trifluoromethanesulfonate.

[0017] Preferably, the base is N,N-diisopropylethylamine, triethylamine, N,N,N',N'-tetramethylethylenediamine, or 4-dimethylaminopyridine.

[0018] Preferably, the organic solvent is any one of toluene, chlorobenzene, fluorobenzene, and N,N-dimethylformamide.

[0019] Preferably, the concentration of rapamycin in the reaction system is 0.1–1.0 mol / L.

[0020] Preferably, rapamycin, additives, alkylating agents, bases, and organic solvents are added to a microwave reaction tube; the microwave conditions during the reaction are: 25–120°C for 1–100 min.

[0021] Preferably, molecular sieves are added along with rapamycin and additives.

[0022] Preferably, the amount of molecular sieve added is 0.5% to 50% of the total weight of the system.

[0023] Preferably, the molecular sieve is Molecular sieves Molecular sieve or Molecular sieve

[0024] Preferably, during washing, the filtrate is first washed once with a saturated sodium bicarbonate solution, and the organic phase is then washed twice with a saturated sodium chloride solution.

[0025] Preferably, the crude product is separated and purified at low temperature, and the eluent during purification is n-hexane:acetone = 90:10 to 80:20.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention provides a method for the alkylation synthesis of the 40-hydroxyl group of rapamycin. First, using rapamycin as a raw material, additives such as triphenylphosphine oxide, tri(4-fluorophenyl)phosphine oxide, tri(4-methoxyphenyl)phosphine oxide, tricyclohexylphosphine oxide, triphenylphosphine sulfide, triphenylphosphine selenide, or hexamethylphosphoric triamine (HMPA) are added, which can significantly improve the reaction yield, reduce the formation of byproducts, and obtain a high-quality product. Second, this method produces fewer impurities, and unreacted raw materials can be separated and recovered by column chromatography for subsequent reactions, reducing reaction costs. Third, the products exhibit significant polarity differences and are easily separated; combined with the advantage of fewer impurities, this further improves separation efficiency. Finally, this reaction is carried out in a microwave environment, completing the reaction in just 5 minutes, greatly shortening the reaction time and resulting in high reaction efficiency. Compared with existing alkylation modification methods for the 40-hydroxyl group of rapamycin, this synthetic method is simple to operate, low in cost, short in reaction time, has fewer impurities, is easy to separate, and has a higher yield of up to 79.1%. It is suitable for industrial production and can provide new ideas for the synthesis and development of rapamycin derivatives such as everolimus.

[0028] Furthermore, the addition of molecular sieves can further improve the yield of the alkylated product of the 40-hydroxyl group of rapamycin.

[0029] Furthermore, the concentration of rapamycin in the reaction system is 0.1–1.0 mol / L, which avoids the use of large amounts of organic solvents, making it green, environmentally friendly, and low-cost. Detailed Implementation

[0030] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0032] The present invention will now be described in further detail:

[0033] This invention provides a method for the alkylation synthesis of the 40-hydroxyl group of rapamycin, and the synthetic route is as follows:

[0034]

[0035] 1. Under an inert gas atmosphere, add rapamycin, molecular sieve and additives sequentially to a microwave reaction tube, followed by alkylating agent, base and organic solvent, and seal the reaction system;

[0036] The additive is triphenylphosphine oxide, tri(4-fluorophenyl)phosphine oxide, tri(4-methoxyphenyl)phosphine oxide, tricyclohexylphosphine oxide, triphenylphosphine sulfide, triphenylphosphine selenide, or hexamethylphosphoric acid triamine (HMPA), preferably triphenylphosphine oxide; the amount of additive added is 1 to 20 molar equivalents of rapamycin, preferably 2 molar equivalents; the alkylating agent is ethyl trifluoromethanesulfonate-2-[tert-butyldimethylsilyl]ester or... 2-(propynyl)trifluoromethanesulfonate; the alkylating agent is added in an amount of 1 to 20 molar equivalents of rapamycin, preferably 10 molar equivalents; the base is N,N-diisopropylethylamine, triethylamine, N,N,N',N'-tetramethylethylenediamine or 4-dimethylaminopyridine, preferably N,N-diisopropylethylamine; the base is added in an amount of 1 to 20 molar equivalents of rapamycin, preferably 12.6 molar equivalents; the molecular sieve is... Molecular sieves Molecular sieve or Molecular sieve, preferably molecular sieve The amount of molecular sieve added is 0.5% to 50% of the total mass of the system, preferably 20%; the organic solvent is any one of toluene, chlorobenzene, fluorobenzene and N,N-dimethylformamide, preferably toluene; in the reaction system, the concentration of rapamycin is 0.1 to 1.0 M, preferably 0.6 M;

[0037] 2. React in a Biotage microwave apparatus at 25–120°C for 1–100 min; the preferred reaction temperature is 65°C; the preferred reaction time is 5 min.

[0038] 3. After the reaction is complete, cool to room temperature, filter, and wash the filter residue with ether. Wash the filtrate once with saturated sodium bicarbonate solution, and then wash the organic phase twice with saturated sodium chloride solution. Finally, add anhydrous sodium sulfate to dry and filter. Remove the solvent from the filtrate under reduced pressure at 20-50°C to obtain the crude product.

[0039] 4. The crude product needs to be separated and purified at low temperature. The eluent is n-hexane:acetone = 90:10 to 80:20. After evaporation, a white foamy product can be obtained.

[0040] Example 1: Synthesis of 40-O-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin

[0041]

[0042] 1. Synthesis of alkylating agent 2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate:

[0043] Under nitrogen protection, anhydrous tetrahydrofuran was added, and the reaction temperature was controlled between 18 and 27 °C. 800 mg of sodium hydride was added, followed by the slow addition of 5.0 mL of ethylene glycol using a constant pressure titration funnel. 3.0 g of tert-butyldimethylchlorosilane was dissolved in anhydrous tetrahydrofuran and slowly added to the reaction system. The reaction was carried out at room temperature for two hours. The mixture was diluted with ethyl acetate, then extracted with saturated sodium chloride solution and pure water. The organic phase was washed twice with saturated sodium chloride solution, dried over anhydrous sodium sulfate, and evaporated under reduced pressure to obtain an oily substance. The oily substance was purified to obtain the desired intermediate. The intermediate and 2,6-dimethylpyridine were dissolved in dichloromethane and cooled to 0–5 °C. Trifluoromethanesulfonic anhydride was then slowly added to the reaction system, and the reaction was continued for 3 hours after the addition was complete. After the reaction was complete, the mixture was brought back to room temperature. Saturated sodium chloride solution and pure water were added to the system. The mixture was extracted three times with ethyl acetate, filtered, dried, and the solvent was removed by vacuum distillation. The concentrate was purified to obtain 2.3 g of colorless oily liquid trifluoromethanesulfonic acid-2-[tert-butyldimethylsilyl]ethyl ester, with a yield of 74%.

[0044] 1 H NMR (400MHz, CDCl3) δ4.58–4.52(m,2H),3.93(d,J=4.6Hz,2H),0.90(s,9H),0.09(s,6H).

[0045] 2. Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0046] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give 75.6 mg of white foamy product, with a yield of 70.6%.

[0047] 11H NMR (400 MHz, CDCl3) δ 6.42–6.28 (m, J = 14.7, 7.6 Hz, 2H), 6.15–6.09 (m, 1H), 5.98–5.92 (dd, J = 10.4, 1.5 Hz, 1H), 5.58–5.50 (m, J = 15.0, 8.7 Hz, 1H), 5.44–5.38 (d, J = 9.9, 1.4 Hz, 1H), 5.30–5.24 (dd, J = 5.6 Hz, 1H), 5.19–5.12 (dd, J = 6.0, 4.1 Hz, 1H), 4.19–4.14 (dt, J = 6.2, 1.7 Hz, 1H), 3.88–3.80 (m, J = 12.4, 6.2 Hz, 1H), 3.73–3.70 (t, J = 5.5 Hz, 3H), 3.66–3.65 (m, 1H), 3.64–3.61 (dd, J = 5.9, 3.2 Hz, 2H), 3.46–3.45 (s, 3H), 3.43–3.42 (d, J = 2.3 Hz, 1H), 3.42–3.41 (d, J = 2.2 Hz, 1H), 3.39–3.37 (s, 1H), 3.33–3.32 (s, 3H), 3.13–3.12 (d, J = 1.3 Hz, 4H), 3.06–3.00 (m, 1H), 2.75–2.69 (m, 2H), 2.61–2.53 (m, J = 16.8, 6.4 Hz, 1H), 2.37–2.28 (m, J = 10.2, 6.4 Hz, 2H), 2.19–2.16 (s, 1H), 2.05–1.97 (m, J = 18.2, 6.3 Hz, 3H), 1.75–1.73 (d, J = 1.3 Hz, 4H), 1.69–1.68 (d, J = 1.3 Hz, 3H), 1.65–1.64 (d, J = 1.3 Hz, 4H), 1.60–1.58 (d, J = 4.2 Hz, 2H), 1.50–1.43 (m, 4H), 1.35–1.29 (m, 2H), 1.22–1.18 (m, J = 2.9 Hz, 2H), 1.10–1.08 (d, J = 6.7 Hz, 3H), 1.05–1.03 (d, 4H), 1.00–0.97 (d, J = 6.5 Hz, 3H), 0.95–0.93 (d, J = 6.5 Hz, 2H), 0.91–0.90 (s, 2H), 0.89–0.88 (d, J = 1.9 Hz, 15H), 0.77–0.63 (m, 2H), 0.07–0.03 (s, 6H).

[0048] LCMS (ESI) m / z: C 59 H 97 NO 14 Si of [M+Na]+ Calculated value: 1094.67; Measured value: 1094.24.

[0049] Simultaneously, 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin was synthesized in solution as a control experiment. The experimental steps are as follows:

[0050] Under nitrogen protection, 91.4 mg of rapamycin, the raw material, was added sequentially to the reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-(tert-butyldimethylsilyl)ethyl trifluoromethanesulfonate and 220 μL of base—N,N-diisopropylethylamine. Finally, 166 μL of solvent toluene was added. The reaction system was sealed and stirred in an oil bath at 65 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give 28.5 mg of white foamy product, with a yield of 26.6%. NMR data were the same as above.

[0051] The yields of the microwave synthesis method and the traditional solution system synthesis method were compared, and the results are shown in Table 1:

[0052] Table 1. Comparison of yields between microwave synthesis and traditional solution synthesis methods

[0053]

[0054] As shown in Table 1, compared with the traditional solution synthesis method, the microwave synthesis method has a shorter reaction time and a higher yield.

[0055] Example 2: Synthesis of 40-O-[2-(propynyl)oxy]ethyl-rapamycin

[0056]

[0057] 1. Synthesis of the alkylating agent 2-(propynyl)trifluoromethanesulfonate:

[0058] Under nitrogen protection, 40 mL of anhydrous ethylene glycol was added to the reaction system. At approximately 0 °C, 7 g of sodium hydride was slowly added. After the bubbles disappeared, propargyl bromide (80% w / t in Toluene) was slowly added dropwise using a constant pressure titration funnel. After the addition was complete, the reaction apparatus was transferred to a 45 °C oil bath and reacted for 3 hours to terminate the reaction. The mixture was diluted with pure water and extracted three times with ethyl acetate. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the filtrate was evaporated to dryness. The filtrate was purified by column chromatography to obtain a colorless oily liquid intermediate. The intermediate and a solution of 2,6-dimethylpyridine were placed in dichloromethane and cooled to 0–5 °C. Then, trifluoromethanesulfonic anhydride was slowly added dropwise to the reaction system. After the addition was complete, the reaction was continued for 3 hours. After the reaction was complete, the mixture was brought back to room temperature. Saturated sodium chloride solution and pure water were added to the system. The mixture was extracted three times with ethyl acetate, filtered, dried, and the solvent was removed by vacuum distillation. The concentrate was purified to obtain 1.8 g of orange-red oily liquid trifluoromethanesulfonic acid-2-(propynyl)ethyl ester, with a yield of 78.2%.

[0059] 1 H NMR (400MHz, CDCl3) δ4.68–4.61(m,2H),4.23(d,J=2.4Hz,2H),3.90–3.83(m,2H),2.49(t,J=2.4Hz,1H).

[0060] 2. Synthesis of 40-oxo-[2-(propynyl)oxy]ethyl-rapamycin:

[0061] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by the addition of 218 mg of alkylating agent—2-(propynyl)trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the residue was washed with ethyl acetate until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:ethyl acetate as the eluent at a ratio of 80:20 to 50:50. The product was evaporated to dryness to obtain a white foamy product, 78.8 mg, with a yield of 79.1%.

[0062] 1H NMR(400MHz, CDCl3) δ6.41–6.31(m,J=16.8,15.9,10.2Hz,2H),6.17–6.10(m,J=15.0,9.8Hz,1H),5.99–5 .92(d,J=10.3Hz,1H),5.59–5.50(m,J=15.1,8.8Hz,1H),5.43–5.38(d,J=9.8Hz,1H),5.30–5.25(d,J=5. 7Hz,1H),5.19–5.13(d,J=5.8Hz,1H),4.23–4.19(d,J=2.3Hz,5H),4.18–4.16(d,J=5.7Hz,1H),4.15–4.0 7(q,J=7.1Hz,1H),3.79–3.76(m,J=6.4,2.7Hz,4H),3.71–3.65(m,J=11.6,5.0Hz,6H),3.46–3.42(d,J=10 .5Hz, 6H), 3.35–3.31 (s, 4H), 3.19–3.07 (m, 7H), 2.78–2.67 (dd, J=16.6, 5.8Hz, 2H), 2.62–2.54 (dd, J=16 .8,6.4Hz,1H),2.47–2.41(m,J=17.0,2.4Hz,2H),2.38–2.30(d,J=13.5Hz,2H),2.05–2.03(s,2H),1.76–1 .73(m,J=4.0Hz,6H),1.69–1.64(m,J=16.9Hz,9H),1.49–1.43(m,4H),1.28–1.23(m,4H),1.10–1.03(dd, J=18.8,6.6Hz,9H),1.00–0.97(d,J=6.5Hz,3H),0.96–0.93(d,J=6.6Hz,3H),0.91–0.88(d,J=6.7Hz,4H).

[0063] LCMS(ESI)m / z:C 56 H85NO 14 of[M+Na] + Calculated value: 1019.29; Measured value: 1019.39.

[0064] Example 3: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0065] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate and 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted in a Biotage microwave apparatus at 65 °C for 5 min. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give 67.0 mg of white foamy product, with a yield of 62.6%.

[0066] Example 4: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0067] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate and 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give 70.0 mg of white foamy product, with a yield of 65.4%.

[0068] Example 5: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0069] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate and 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted in a Biotage microwave apparatus at 65 °C for 100 min. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to obtain a white foamy product, 12.8 mg, yield 12.0%.

[0070] Example 6: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0071] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate and 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 1 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to obtain a white foamy product, 54.2 mg, with a yield of 50.6%.

[0072] Example 7: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0073] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 120 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to obtain a white foamy product, 32.9 mg, with a yield of 30.7%.

[0074] Example 8: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0075] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 58.9 mg of triphenylphosphine sulfide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give 60.8 mg of white foamy product, with a yield of 56.8%.

[0076] Example 9: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0077] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 96.4 mg of tri(4-fluorophenyl)phosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted in a Biotage microwave apparatus at 65 °C for 5 min. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give a white foamy product, 39.6 mg, with a yield of 37.0%.

[0078] Example 10: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0079] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 68.2 mg of triphenylphosphine selenide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give 46.7 mg of white foamy product, with a yield of 43.6%.

[0080] Example 11: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0081] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 34.8 μL of hexamethylphosphoric triamine (HMPA) were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted in a Biotage microwave apparatus at 65 °C for 5 min. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The filtrate was subjected to reduced pressure at 20–50 °C to remove the solvent and obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to obtain a white foamy product, 69.5 mg, with a yield of 64.9%.

[0082] Example 12: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0083] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 59.3 mg of tricyclohexylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was then evaporated to dryness to obtain a white foamy product, 51.1 mg, with a yield of 47.7%. The NMR data were the same as in Example 1.

[0084] Example 13: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0085] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 73.6 mg of tris(4-methoxyphenyl)phosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to obtain a white foamy product, 58.9 mg, yield 55.0%. The NMR data were the same as in Example 1.

[0086] Example 14: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0087] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent fluorobenzene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to obtain a white foamy product, 53.7 mg, with a yield of 50.1%.

[0088] Example 15: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0089] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent—N,N-dimethylformamide. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to obtain a white foamy product, 16.1 mg, yield 15.0%.

[0090] Example 16: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0091] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 220 μL of base—N,N-diisopropylethylamine, and 166 μL of solvent chlorobenzene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give 46.6 mg of white foamy product, with a yield of 43.5%.

[0092] Example 17: Synthesis of 40-O-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0093] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate and 169.9 μL of base—4-dimethylaminopyridine, and 166 μL of solvent toluene. The reaction system was sealed and reacted in a Biotage microwave apparatus at 65 °C for 5 min. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give 43.9 mg of white foamy product, yield 41.0%.

[0094] Example 18: Synthesis of 40-O-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0095] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate and 174.8 μL of base—triethylamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted in a Biotage microwave apparatus at 65 °C for 5 min. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was obtained by rotary evaporation and dried to give a white foamy product, 39.6 mg, with a yield of 37.0%.

[0096] Example 19: Synthesis of 40-oxo-[2-(tert-butyldimethsilyl)oxy]ethyl-rapamycin:

[0097] Under nitrogen protection, 91.4 mg of rapamycin was added sequentially to the microwave reaction tube. 40 mg of molecular sieve and 55.6 mg of triphenylphosphine oxide were added, followed by 260 μL of alkylating agent—2-[tert-butyldimethylsilyl]ethyl trifluoromethanesulfonate, 188.6 μL of base—N,N,N',N'-tetramethylethylenediamine, and 166 μL of solvent toluene. The reaction system was sealed and reacted for 5 min at 65 °C in a Biotage microwave apparatus. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter residue was washed with diethyl ether until the eluent was colorless. The filtrate was washed once with saturated sodium bicarbonate solution, and the organic phase was washed twice with saturated sodium chloride solution. Finally, anhydrous sodium sulfate was added for drying and filtration. The solvent was removed from the filtrate under reduced pressure at 20–50 °C to obtain the crude product. The crude product was separated by column chromatography with hexane:acetone = 90:10 to 80:20 as the eluent. The product was evaporated to dryness to obtain a white foamy product, 51.4 mg, yield 48.0%. NMR data were the same as in Example 1.

[0098] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for the alkylation synthesis of the 40-hydroxyl group of rapamycin, characterized in that, In an inert gas atmosphere, rapamycin and additives were added sequentially, followed by alkylating reagent, base and organic solvent. The mixture was reacted under microwave conditions at 65°C for 1-5 min. The mixture was then filtered, washed, dried, filtered again, separated and purified to obtain the alkylated product of the 40-hydroxyl group of rapamycin. The additive is triphenylphosphine oxide, tri(4-fluorophenyl)phosphine oxide, tri(4-methoxyphenyl)phosphine oxide, tricyclohexylphosphine oxide, triphenylphosphine sulfide, triphenylphosphine selenide, or hexamethylphosphoric triamine; the alkylating agent is ethyl trifluoromethanesulfonate-2-[tert-butyldimethylsilyl]triethyl or ethyl trifluoromethanesulfonate-2-(propynyl)triethyl; and the organic solvent is any one of toluene, chlorobenzene, and fluorobenzene.

2. The method for alkylating the 40-hydroxyl group of rapamycin according to claim 1, characterized in that, The amount of additive added is 1 to 20 molar equivalents of rapamycin; the amount of alkylating agent added is 1 to 20 molar equivalents of rapamycin; the amount of base added is 1 to 20 molar equivalents of rapamycin.

3. The method for alkylating the 40-hydroxyl group of rapamycin according to claim 1, characterized in that, The base is N,N-diisopropylethylamine, triethylamine, N,N,N',N'-tetramethylethylenediamine, or 4-dimethylaminopyridine.

4. The method for alkylating the 40-hydroxyl group of rapamycin according to claim 1, characterized in that, In the reaction system, the concentration of rapamycin is 0.1~1.0 mol / L.

5. The method for alkylating the 40-hydroxyl group of rapamycin according to any one of claims 1 to 4, characterized in that, Molecular sieves are added along with rapamycin and additives.

6. The method for alkylating the 40-hydroxyl group of rapamycin according to claim 5, characterized in that, The amount of molecular sieve added is 0.5% to 50% of the total weight in the system.

7. The method for alkylating the 40-hydroxyl group of rapamycin according to claim 5, characterized in that, The molecular sieve is a 5Å molecular sieve, a 4Å molecular sieve, or a 3Å molecular sieve.

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