Preparation method of 2 '-modified ribose derivative

Abstract

The invention discloses a preparation method of a 2 '-modified ribose derivative, 2'-modified nucleoside is taken as a raw material, hydroxyl is subjected to benzoyl protection, basic groups are removed by a one-step method, and 1-site is acetylated, so that the ribose derivative with wide application is obtained, the preparation method is simple, the reaction condition is mild, the synthesis efficiency is high, and the preparation method is environment-friendly. The method is suitable for large-scale production, and the preparation method has good substrate applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of pharmaceutical intermediate synthesis, and particularly relates to a method for preparing a 2'-modified ribose derivative. Background Art

[0002] The effectiveness of therapeutic RNA delivery outside the liver is a fundamental obstacle to its clinical application. Conjugate-mediated delivery is becoming the main clinical delivery paradigm for siRNA. Among them, targeting the asialoglycoprotein receptor (ASGPR) on the surface of hepatocytes is widely used for siRNA / mRNA liver-targeted delivery. In addition, lipids are also the main type of conjugates widely used to improve siRNA delivery, because lipid conjugation increases the plasma half-life and enhances the tissue accumulation and cellular uptake of siRNA.

[0003] Chinese patent CN119213004A discloses lipid monomers for therapeutic delivery of RNA, wherein a 2'-modified ribose derivative compound 6 is disclosed as a novel lipid delivery system for delivering siRNA to tissues other than the liver. The structural formula of the compound 6 is:

[0004]

[0005] Chinese patent CN116854754A discloses a GalNAc compound containing a ribose ring or its derivative structure and its oligonucleotide conjugate. It discloses combining a 2'-modified ribose derivative with N-acetylgalactosamine (GalNAc) to form a novel GalNAc compound, YK-GAL-305, and using it to prepare a GalNAc oligonucleotide conjugate. The structural formula of YK-GAL-305 is:

[0006]

[0007] All of the above patents use 2'-modified ribose derivatives as raw materials. The existing methods for preparing 2'-modified ribose, such as 2'-methoxy-modified ribose, often use D-ribose as the raw material and undergo a seven-step reaction to obtain the 2'-modified ribose derivative. This method is lengthy and uses strong acids such as sulfuric acid and hydrobromic acid. The 2'-modification also requires a diazotization reagent, which is highly hazardous and difficult to scale up. Other modifications with more complex structures are even more challenging using existing methods.

[0008] Summary of the Invention

[0009] To solve the above technical problems, the present invention provides a method for preparing a 2'-modified ribose derivative, which has simple preparation methods, mild reaction conditions, high synthesis efficiency, is environmentally friendly, and is more suitable for scale-up production.

[0010] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0011] A method for preparing a 2'-modified ribose derivative. The synthetic route of the 2'-modified ribose derivative is as follows:

[0012]

[0013] Wherein, R is any one of -OMe, -OEt, -OMOE, -F, and -OEOE;

[0014] Base is Wherein R2 is one of H, acetyl, isobutyryl, and benzoyl;

[0015] The preparation method of the 2'-modified ribose derivative comprises the following steps:

[0016] (1) Compound 1 reacts with benzoic anhydride or benzoyl chloride to form compound 2;

[0017] (2) Compound 2 reacts with an acetylating agent to generate compound 3.

[0018] The preparation method of the 2'-modified ribose derivative specifically comprises the following steps:

[0019] (1) Compound 1 is dissolved in an organic solvent, benzoic anhydride or benzoyl chloride and a catalyst are added, and the mixture is stirred at 20-100° C. for 8-12 hours, followed by post-treatment to obtain compound 2;

[0020] (2) Compound 2 is mixed with an acetylating agent, a catalyst is added, and the mixture is stirred at 80-160° C. for 8-12 h, followed by post-treatment to obtain compound 3.

[0021] In step (1), the molar ratio of compound 1 to benzoic anhydride or benzoyl chloride is 1:2-5; the molar ratio of compound 1 to the catalyst is 1:0.05-0.5.

[0022] In step (1), the organic solvent is one or more of DMSO, DMF, and pyridine.

[0023] In step (1), the catalyst is one or more of DMAP, triethylamine, DBU, N-methylmorpholine and diisopropylethylamine.

[0024] In step (1), the reaction temperature is preferably 60-80°C.

[0025] In step (1), the post-treatment method is: extracting and drying the reaction solution, then adding it to an alcohol solvent, heating and refluxing and stirring until dissolved, then cooling and precipitating, and finally filtering and drying.

[0026] The alcohol solvent is selected from one or more of methanol, ethanol, isopropanol and n-propanol.

[0027] In step (2), the molar ratio of compound 2 to the catalyst is 1:0.005-0.05.

[0028] In step (2), the catalyst is one or more of methanesulfonic anhydride, trifluoromethanesulfonic anhydride and p-toluenesulfonic anhydride.

[0029] In step (2), the acetylating agent is selected from one of acetic anhydride and acetyl chloride. The acetylating agent serves as both a reaction reagent and a solvent, and its usage is 3 to 8 times the volume of compound 2.

[0030] In step (2), the post-treatment method is: adding an organic solvent to the reaction solution, filtering, concentrating, and performing column chromatography separation; the organic solvent is at least one of dichloromethane, ethyl acetate, tetrahydrofuran, and 2-methyltetrahydrofuran.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The present invention uses 2'-modified nucleosides as raw materials, breaks through the traditional preparation method, performs simple protection, removes the base in one step, and acetylates the 1-position, thereby obtaining a widely used ribose derivative. Compared with traditional process steps, this preparation method is greatly shortened, simple to operate, and has a high yield, with a two-step yield of more than 70%, and the preparation method has good substrate applicability.

[0033] This compound can be used as a raw material for delivery products and has great industrial potential. When used as a raw material for delivery products, the synthetic route is as follows:

[0034] BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is the H NMR spectrum of compound 2a;

[0036] Figure 2 is the H NMR spectrum of compound 3a;

[0037] Figure 3 is the H NMR spectrum of compound 2b;

[0038] Figure 4 The H NMR spectrum of compound 3b

[0039] Figure 5 is the H NMR spectrum of compound 2c;

[0040] Figure 6 is the H NMR spectrum of compound 3c;

[0041] Figure 7 The synthetic route of the 2'-modified ribose derivatives of the present invention is shown in FIG. DETAILED DESCRIPTION

[0042] The present invention is described in detail below with reference to the embodiments.

[0043] Example 1

[0044] A method for preparing a 2'-modified ribose derivative compound 3a. The synthetic route of the 2'-modified ribose derivative is as follows:

[0045]

[0046] Among them, R is -OMe, Base is R2 is benzoyl.

[0047] The preparation method of the 2'-modified ribose derivative comprises the following steps:

[0048] (1) 500 g of raw material 1a was dissolved in 5 L of DMF by stirring, and 961 g of benzoic anhydride and 21.4 g of DMAP were added. The temperature was raised to 80 °C and stirred overnight. After the reaction was completed, the reaction solution was poured into 20 L of water and stirred. 8 L of ethyl acetate was added, and the upper organic phase was separated and extracted twice with 8 L of sodium chloride solution. The upper organic phase was taken, dried with a small amount of anhydrous sodium sulfate, and dried at 45 °C. 4 L of methanol was added and stirred. The temperature was raised to reflux and stirred to clarify. The temperature was lowered to 0 °C and stirred overnight. The white solid 2a was obtained by suction filtration. 705.3 g, molar yield: 91.58%, 1HNMR (400 MHz, DMSO) δ11.28 (s, 1H), 8.81–8.75 (m, 1H), 8.69–8.61 (m, 1H), 8.19–7.98 (m, 6H), 7.77–7.45 (m, 9H), 6.41–6.34 (m, 1H), 6.02 (d, J=2.7 Hz, 1H), 5.22 (s, 1H), 4.76 (d, J=11.5 Hz, 2H), 4.71 (d, J=6.3 Hz, 1H), 3.36 (s, 3H). Figure 1 shown.

[0049] (2) 300 g of raw material 2a was dissolved in 1.5 L of acetic anhydride, and 1.12 g of trifluoromethanesulfonic anhydride was added. The reaction was stirred at 140° C. overnight until completion, and the temperature was lowered to 55° C. and dried by spin drying. The product was dissolved in 1.5 L of dichloromethane and filtered. During the filtration, a layer of silica gel and diatomaceous earth was laid on the upper layer of the filter paper. The filtrate was concentrated and then separated and purified by polar column chromatography with n-hexane / ethyl acetate = 10:1 to 1:1 (volume ratio) as the eluent to obtain 170 g of oily compound 3a in a yield of 81.17%. 1H NMR(400MHz, DMSO)δ8.07–7.97(m,4H),7.69(ddd,J=18.4,10.6,4.4Hz,2H),7.61–7.49(m,4H),6.43–6.05(m,1H),5.57 (ddd,J=11.3,6.1,3.3Hz,1H),4.71–4.59(m,2H),4.50–4.39(m,1H),4.28–4.18(m,1H),3.33(s,3H),2.13–1.89(m,3H). like Figure 2 shown.

[0050] Example 2

[0051] A method for preparing a 2'-modified ribose derivative compound 3b. The synthetic route of the 2'-modified ribose derivative is as follows:

[0052]

[0053] Among them, R is -OMOE, Base is R2 is benzoyl.

[0054] The preparation method of the 2'-modified ribose derivative comprises the following steps:

[0055] 500 g of raw material 1b was dissolved in 4.8 L of DMF by stirring, and 971 g of benzoic anhydride and 22.3 g of DMAP were added. The temperature was raised to 80° C. and stirred overnight. After the reaction was completed, the reaction solution was poured into 20 L of water and stirred. 8 L of ethyl acetate was added, and the upper organic phase was separated and extracted twice with 8 L × 2 sodium chloride solution. The upper organic phase was taken, dried with a small amount of anhydrous sodium sulfate, and dried at 45° C. After being added with 4 L of methanol and stirred, the temperature was raised to reflux and stirred to clarify. The temperature was lowered to 0° C. and stirred overnight. Filtered to obtain 685.80 g of white solid 2b. The yield was 92.37%. NMR (400MHz, DMSO) δ11.25(s,1H),8.74(d,J=3.2Hz,1H),8.62(d,J=3.2Hz,1H),8.15–7.99(m,6H),7.79–7.42(m,9H),6. 37–6.29(m,1H),5.96(d,J=3.1Hz,1H),5.36(d,J=4.6Hz,1H),4.79–4.60(m,3H),3.65(m,2H),3.26(m,2H),2.93(s,3H). like Figure 3 shown.

[0056] 300 g of raw material 2b was dissolved in 1.5 L of acetic anhydride, and 1.69 g of trifluoromethanesulfonic anhydride was added. The reaction was stirred at 140°C overnight until complete, then cooled to 55°C and dried by spin drying. The product was then dissolved in 1.5 L of dichloromethane and filtered. During filtration, the filter paper was covered with a layer of silica gel and diatomaceous earth. The filtrate was concentrated and then separated and purified by polar column chromatography with n-hexane / ethyl acetate = 12:1 to 2:1 (volume ratio) as the eluent to obtain 173.60 g of oily compound 3b in a yield of 80.5%. 1H NMR (400MHz, DMSO) δ8.10–7.98(m,4H),7.71–7.62(m,2H),7.58–7.47(m,4H),6.44–6.09(m,1H),5.57(m,1H),4 .71–4.61(m,2H),4.54–4.34(m,2H),3.77–3.61(m,2H),3.40–3.31(m,2H),3.10(d,J=1.3Hz,3H),1.90(s,3H). like Figure 4 shown.

[0057] Example 3

[0058] A method for preparing a 2'-modified ribose derivative compound 3c. The synthetic route of the 2'-modified ribose derivative is as follows:

[0059]

[0060] Among them, R is -F, Base is R2 is benzoyl.

[0061] The preparation method of the 2'-modified ribose derivative comprises the following steps:

[0062] 500 g of raw material 1c was dissolved in DMF by stirring, and 952 g of benzoic anhydride and 20.5 g of DMAP were added. The mixture was heated to 80°C and stirred overnight. After the reaction was completed, the reaction solution was poured into 20 L of water and stirred. 8 L of ethyl acetate was added, and the upper organic phase was separated and extracted twice with 8 L × 2 sodium chloride solution. The upper organic phase was taken, dried with a small amount of anhydrous sodium sulfate, and dried at 45°C. 4 L of methanol was added and stirred. The mixture was heated to reflux and stirred to clarify. The temperature was lowered to 0°C and stirred overnight. Filtered to obtain 705 g of white solid 2c. Yield: 91.95%. NMR (400MHz, DMSO) δ11.28(s,1H),8.68(d,J=22.7Hz,2H),8.07(dd,J=13.6,8.0Hz,4H),7.90(d,J=7.9Hz,2H),7.74(t,J=7.1Hz,1H),7.68 –7.54(m,6H),7.48(t,J=7.2Hz,2H),6.63(d,J=20.6Hz,1H),6.30–6.12(m,2H),4.79(dd,J=17.0,8.7Hz,2H),4.63(dd,J=12.0,4.1Hz,1H). like Figure 5 shown.

[0063] 300 g of raw material 2c was dissolved in 1.5 L of acetic anhydride, and 2.1 g of trifluoromethanesulfonic anhydride was added. The reaction was stirred at 140°C overnight until complete, then cooled to 55°C and dried by spin drying. The product was then dissolved in 1.5 L of dichloromethane and filtered. During filtration, the filter paper was covered with a layer of silica gel and diatomaceous earth. The filtrate was concentrated and then purified by polar column chromatography using n-hexane / ethyl acetate = 8:1 to 1:1 (volume ratio) as the eluent to obtain 164.80 g of oily compound 3c in a yield of 79.4%. 1H NMR (400MHz, CDCl3) δ8.14-7.97(m,4H),7.71–7.25(m,6H),6.38(dd,J=10.1,3.1Hz,1H),5.60(m,1H) ,5.26(dd,J=52.1,3.5Hz,1H),4.76(dd,J=7.8,4.7Hz,2H),4.58–4.40(m,1H),1.93(d,J=3.4Hz,3H). like Figure 6 shown.

[0064] Example 4

[0065] With reference to the preparation method in Example 1, screening experiments of different bases were carried out. The results are shown in Table 1. The screening experiments show that when the base is a purine structure, its reactivity is better, and the reaction conditions of the present invention have good substrate trialability.

[0066] Table 1

[0067]

[0068]

[0069] The detailed description of the preparation method of a 2'-modified ribose derivative with reference to the above examples is illustrative rather than restrictive. Several examples can be listed according to the limited scope. Therefore, changes and modifications without departing from the overall concept of the present invention should fall within the scope of protection of the present invention.

Claims

1. A method for preparing a 2'-modified ribose derivative, characterized in that: The synthetic route of the 2'-modified ribose derivative is as follows: Wherein, R is any one of -OMe, -OEt, -OMOE, -F, and -OEOE; Base is Wherein R2 is one of H, acetyl, isobutyryl, and benzoyl; The preparation method of the 2'-modified ribose derivative comprises the following steps: (1) Compound 1 reacts with benzoic anhydride or benzoyl chloride to form compound 2; (2) Compound 2 reacts with an acetylating agent to generate compound 3.

2. The preparation method according to claim 1, characterized in that The preparation method of the 2'-modified ribose derivative comprises the following steps: (1) Compound 1 is dissolved in an organic solvent, benzoic anhydride or benzoyl chloride and a catalyst are added, and the mixture is stirred at 20-100° C. for 8-12 hours, followed by post-treatment to obtain compound 2; (2) Compound 2 is mixed with an acetylating agent, a catalyst is added, and the mixture is stirred at 80-160° C. for 8-12 h, followed by post-treatment to obtain compound 3.

3. The preparation method according to claim 1 or 2, characterized in that In step (1), the molar ratio of compound 1 to benzoic anhydride or benzoyl chloride is 1:2-5; the molar ratio of compound 1 to the catalyst is 1:0.05-0.

5.

4. The preparation method according to claim 1 or 2, characterized in that In step (1), the organic solvent is one or more of DMSO, DMF, and pyridine.

5. The preparation method according to claim 1 or 2, characterized in that In step (1), the catalyst is one or more of DMAP, triethylamine, DBU, N-methylmorpholine and diisopropylethylamine.

6. The preparation method according to claim 1 or 2, characterized in that In step (1), the post-treatment method is: extracting and drying the reaction solution, then adding it to an alcohol solvent, heating and refluxing and stirring until dissolved, then cooling and precipitating, and finally filtering and drying.

7. The preparation method according to claim 6, characterized in that The alcohol solvent is selected from one or more of methanol, ethanol, isopropanol and n-propanol.

8. The preparation method according to claim 1 or 2, characterized in that In step (2), the molar ratio of compound 2 to the catalyst is 1:0.005-0.

05.

9. The preparation method according to claim 1 or 2, characterized in that: In step (2), the catalyst is one or more of methanesulfonic anhydride, trifluoromethanesulfonic anhydride and p-toluenesulfonic anhydride.

10. The preparation method according to claim 1 or 2, characterized in that: In step (2), the acetylating agent is selected from one of acetic anhydride and acetyl chloride. The acetylating agent serves as both a reaction reagent and a solvent, and its usage is 3 to 8 times the volume of compound 2.

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