The invention relates to 3apos; novel synthesis method of-methoxy nucleoside

Abstract

The invention provides a novel synthesis method of 3 '-methoxy nucleoside, which comprises the following steps: carrying out hydroxyl protection reaction on a compound as shown in a structural formula I and a hydroxyl protection reagent to obtain a compound as shown in a structural formula II; performing methoxy nucleophilic substitution reaction on the compound as shown in the structural formula II and methanol alkali metal salt to obtain a compound as shown in a structural formula III; and carrying out hydroxyl deprotection reaction on the compound as shown in the structural formula III to obtain a compound as shown in a structural formula IV, namely the 3 '-methoxy nucleoside. The novel synthesis method of the 3 '-methoxy nucleoside, provided by the invention, has the advantages of easily available raw materials, low cost, safety, high efficiency, simple route and convenience in operation, and is suitable for industrial production.

Description

Technical Field

[0001] The invention belongs to the technical field of biopharmaceutical intermediates, and in particular relates to a new synthesis method of 3'-methoxy nucleoside. Background Art

[0002] The 5′ end of most messenger RNAs (mRNAs) is blocked or capped to promote their normal function in cells. 3′-methoxy nucleosides are widely used in the synthesis of chain-terminating dinucleotide mRNA cap analogs and can also serve as anti-reverse cap analogs to promote the translation of transcripts into proteins.

[0003] The currently reported routes for synthesizing 3′-methoxy nucleosides are as follows:

[0004] For example, SE Bernier group reported a synthetic route of 3'-methoxy nucleoside, which is as follows:

[0005]

[0006] The limitation of this method is that it uses diazomethane, which has poor safety.

[0007] For example, patent publication CN112661802A also reports a synthetic route for 3′-methoxy nucleoside, which is as follows:

[0008]

[0009] The disadvantages of this method are long route and high cost.

[0010] In summary, although there are various methods for synthesizing 3′-methoxy nucleosides, they still face some problems, such as long routes, high costs, and poor safety. Summary of the invention

[0011] Based on the above technical problems, the present invention provides a new synthesis method of 3′-methoxy nucleoside, which has easy-to-obtain raw materials, low cost, safety and high efficiency, and a simple route, convenient operation and is suitable for industrial production.

[0012] The present invention provides a novel method for synthesizing 3′-methoxy nucleosides, comprising the following steps:

[0013] S1, subjecting the compound represented by structural formula I to a hydroxyl protecting reaction with a hydroxyl protecting agent to obtain a compound represented by structural formula II;

[0014] S2, subjecting the compound represented by structural formula II to a methoxy nucleophilic substitution reaction with an alkali metal salt of methanol to obtain a compound represented by structural formula III;

[0015] S3, subjecting the compound represented by structural formula III to hydroxyl deprotection reaction to obtain the compound represented by structural formula IV, which is the 3′-methoxy nucleoside;

[0016]

[0017] Wherein, P is a hydroxyl protecting group on the sugar group, and B is a natural or modified nucleoside base.

[0018] Preferably, P is at least one of THP, Bn, Ac, TBS, TIPS, Piv, Bz, Boc, TBDPS, TMS, PMB, Tr, MMT, TBDMS, DMT or MOM, preferably tetrahydropyranyl THP.

[0019] Preferably, B is a natural adenine base or a guanine base, and its structural formula is shown below:

[0020]

[0021] Preferably, in step S1, the hydroxyl protecting agent is 3,4-dihydro-2H-pyran DHP;

[0022] Preferably, the hydroxyl protection reaction is carried out under the reaction conditions of an acid catalyst and an organic solvent;

[0023] Preferably, the acid catalyst is at least one of pyridinium p-toluenesulfonate, p-toluenesulfonic acid, methanesulfonic acid or sulfuric acid;

[0024] Preferably, the solvent is at least one of toluene, ethyl acetate, dichloromethane, dichloroethane, acetonitrile, tetrahydrofuran, N,N-dimethylformamide or dimethyl sulfoxide;

[0025] Preferably, the temperature of the hydroxyl protection reaction is 10-30°C and the time is 12-24h.

[0026] Preferably, the molar ratio of the compound represented by structural formula I to the hydroxyl protecting agent is 1:2-4, preferably 1:3; the molar ratio of the compound represented by structural formula I to the acid catalyst is 10:0.5-2, preferably 10:1.

[0027] Preferably, in step S2, the alkali metal methanol salt is at least one of sodium methanolate, potassium methanolate or lithium methanolate;

[0028] Preferably, the solvent for the methoxy nucleophilic substitution reaction is at least one of methanol, toluene, acetonitrile, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide or 1,4-dioxane;

[0029] Preferably, the temperature of the methoxy nucleophilic substitution reaction is 25-35° C. and the time is 6-12 h.

[0030] Preferably, the molar ratio of the compound represented by structural formula II to the alkali metal salt of methanol is 1:1-3, preferably 1:2.

[0031] Preferably, in step S3, the hydroxyl deprotection reaction is carried out under the reaction conditions of an acid catalyst and an alcohol solvent;

[0032] Preferably, the acid catalyst is at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, methanesulfonic acid or p-toluenesulfonic acid;

[0033] Preferably, the alcohol solvent is at least one of methanol, ethanol or isopropanol;

[0034] Preferably, the temperature of the hydroxyl deprotection reaction is 25-35°C and the time is 6-12h;

[0035] Preferably, the molar ratio of the compound represented by structural formula III to the acid catalyst is 10:0.5-2, preferably 10:1.

[0036] Preferably, the 3′-methoxy nucleoside is 3′-methoxyadenine nucleoside, and its synthesis route is as follows:

[0037]

[0038] Preferably, the 3′-methoxy nucleoside is 3′-methoxyguanosine nucleoside, and its synthesis route is as follows:

[0039]

[0040] The present invention provides a novel synthesis method of 3'-methoxy nucleoside, which uses the compound shown in structural formula I as a starting material, performs hydroxyl protection, and then performs methoxy nucleophilic substitution reaction with methanol alkali metal salt, and then deprotects to obtain the 3'-methoxy nucleoside. Compared with other synthesis methods in the prior art, the present invention can obtain 3'-methoxy nucleoside with high yield on the one hand; on the other hand, the entire synthesis condition is mild, environmentally friendly, and can be extended to industrial production. DETAILED DESCRIPTION

[0041] Hereinafter, the present invention will describe the technical solution in detail through specific embodiments, but it should be clearly stated that these embodiments are for illustration only and are not to be construed as limiting the scope of the present invention.

[0042] Example 1

[0043] This embodiment proposes a new synthesis method of 3'-methoxy nucleoside, and its specific synthesis method is as follows:

[0044] (1) Compound A1 (50.0 g, 1 eq) and N,N-dimethylformamide (150 mL, 3 eq) were added to a 500 mL three-necked flask, followed by 3,4-dihydro-2H-pyran (38.2 g, 3 eq) and pyridinium p-toluenesulfonate (3.8 g, 0.1 eq). The mixture was stirred at 25° C. for 16 h, and potassium carbonate powder (2.1 g) was added and stirred for 2 h. The reaction solution was introduced into ice water (500 mL), filtered, and washed with water. The obtained solid was added into ethyl acetate (200 mL), slurried at room temperature for 2 h, filtered, and dried to obtain Compound A2 (72.1 g, yield 95.6%, purity 99.5%).

[0045]

[0046] (2) Compound A2 (50 g, 1 eq) and anhydrous methanol (250 mL, 5 v) were added to a 500 mL three-necked flask, followed by sodium methoxide (10.8 g, 2 eq), and the mixture was stirred at 30°C for 8 h. Acetic acid (6.0 g, 1 eq) was added, and the resulting reaction solution was introduced into water (250 mL), concentrated under reduced pressure to remove methanol, filtered, and washed with water. The resulting solid was added to ethyl acetate (150 mL), slurried at room temperature for 1 h, filtered, and dried to obtain compound A3 (42.2 g, yield 93.7%, purity 99.0%);

[0047]

[0048] (3) Compound A3 (50 g, 1 eq) and methanol (500 mL, 10 v) were added to a 1000 mL three-necked flask, and p-toluenesulfonic acid (1.9 g, 0.1 eq) was added. The mixture was stirred at 30° C. for 8 h, filtered, and dried to obtain compound A4 (28.7 g, yield 91.8%, purity 99.1%). 1 HNMR(400MHz,MeOH-d4)δ3.51(3H,s),3.71(1H,m),3.92(1H,m),3.97(1H,m),4.38(1H,m),4.89(1H,m),5.52(1H,m),8.20(1H,s),8.34(1H,s).

[0049]

[0050] When carrying out Examples 2-4, in step (1), an equivalent amount of p-toluenesulfonic acid, methanesulfonic acid or sulfuric acid is used to replace p-toluenesulfonic acid pyridinium salt, and the yields of the obtained compound A2 are 91.4%, 88.7% and 79.2%, respectively; when carrying out Examples 5-6, in step (2), an equivalent amount of potassium methoxide or lithium methoxide is used to replace sodium methoxide, and the yields of the obtained compound A3 are 82.3% and 86.8%, respectively; when carrying out Examples 7-11, in step (3), an equivalent amount of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or methanesulfonic acid is used to replace p-toluenesulfonic acid, and the yields of the obtained compound A4 are 82.3%, 86.1%, 85.5%, 93.2% and 90.5%, respectively.

[0051] Example 12

[0052] This embodiment proposes a new synthesis method of 3'-methoxy nucleoside, and its specific synthesis method is as follows:

[0053] (1) Compound B1 (50 g, 1 eq) and N,N-dimethylformamide (150 mL, 3 eq) were added to a 500 mL three-necked flask, followed by 3,4-dihydro-2H-pyran (36.4 g, 3 eq) and pyridinium p-toluenesulfonate (3.6 g, 0.1 eq), stirred at 25°C for 16 h, and then potassium carbonate powder (2.0 g) was added and stirred for 2 h. The reaction solution was introduced into ice water (500 mL), filtered, and washed with water. The obtained solid was added into ethyl acetate (200 mL), slurried at room temperature for 2 h, filtered, and dried to obtain compound B2 (69.3 g, yield 93.3%, purity 99.5%);

[0054]

[0055] (2) Compound B2 (50 g, 1 eq) and anhydrous methanol (250 mL, 5 eq) were added to a 500 mL three-necked flask, followed by sodium methoxide (10.5 g, 2 eq), and the mixture was stirred at 30°C for 8 h. Acetic acid (5.8 g, 1 eq) was added, and the resulting reaction solution was introduced into water (250 mL), concentrated under reduced pressure to remove methanol, filtered, and washed with water. The resulting solid was added to ethyl acetate (150 mL), slurried at room temperature for 1 h, filtered, and dried to obtain compound B3 (42.7 g, yield 94.4%, purity 99.0%);

[0056]

[0057] (3) Compound B3 (50 g, 1 eq) and methanol (500 mL, 10 v) were added to a 1000 mL three-necked flask, and p-toluenesulfonic acid (1.85 g, 0.1 eq) was added. The mixture was stirred at 30° C. for 8 h, filtered, and dried to obtain compound B4 (29.9 g, yield 93.6%, purity 99.2%).1 HNMR(400MHz,DMSO-d6)δ3.42(3H,s),3.55(1H,m),3.61(1H,m),3.84(1H,m),3.98(1H,m),4. 57(1H,m),5.26(1H,sbr),5.48(1H,s),5.71(1H,m),6.13(2H,m),7.90(1H,s),10.78(1H,m).

[0058]

[0059] When carrying out Examples 13-15, in step (1), an equivalent amount of p-toluenesulfonic acid, methanesulfonic acid or sulfuric acid is used to replace p-toluenesulfonic acid pyridinium salt, respectively, and the yields of the obtained compound B2 are 90.5%, 87.6% and 81.4%, respectively; when carrying out Examples 16-17, in step (2), an equivalent amount of potassium methoxide or lithium methoxide is used to replace sodium methoxide, and the yields of the obtained compound B3 are 85.6% and 88.1%, respectively; when carrying out Examples 18-22, in step (3), an equivalent amount of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid or methanesulfonic acid is used to replace p-toluenesulfonic acid, and the yields of the obtained compound B4 are 83.2%, 87.5%, 88.2%, 91.7% and 89.1%, respectively.

[0060] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A novel method for synthesizing 3'-methoxy nucleosides, characterized in that: The steps include: S1, subjecting the compound represented by structural formula I to a hydroxyl protecting reaction with a hydroxyl protecting agent to obtain a compound represented by structural formula II; S2, subjecting the compound represented by structural formula II to a methoxy nucleophilic substitution reaction with an alkali metal salt of methanol to obtain a compound represented by structural formula III; S3, subjecting the compound represented by structural formula III to hydroxyl deprotection reaction to obtain the compound represented by structural formula IV, which is the 3'-methoxy nucleoside; Wherein, P is a hydroxyl protecting group on the sugar group, and B is a natural or modified nucleoside base.

2. The novel method for synthesizing 3'-methoxy nucleosides according to claim 1, characterized in that: P is at least one of THP, Bn, Ac, TBS, TIPS, Piv, Bz, Boc, TBDPS, TMS, PMB, Tr, MMT, TBDMS, DMT or MOM, preferably tetrahydropyranyl THP.

3. The novel method for synthesizing 3'-methoxy nucleosides according to claim 1 or 2, characterized in that: B is a natural adenine base or guanine base, and its structural formula is shown below:

4. A novel method for synthesizing 3'-methoxy nucleosides according to any one of claims 1 to 3, characterized in that: In step S1, the hydroxyl protecting agent is 3,4-dihydro-2H-pyran DHP; Preferably, the hydroxyl protection reaction is carried out under the reaction conditions of an acid catalyst and an organic solvent; Preferably, the acid catalyst is at least one of pyridinium p-toluenesulfonate, p-toluenesulfonic acid, methanesulfonic acid or sulfuric acid; Preferably, the solvent is at least one of toluene, ethyl acetate, dichloromethane, dichloroethane, acetonitrile, tetrahydrofuran, N,N-dimethylformamide or dimethyl sulfoxide; Preferably, the temperature of the hydroxyl protection reaction is 10-30°C and the time is 12-24h.

5. The novel method for synthesizing 3'-methoxy nucleosides according to claim 4, characterized in that: The molar ratio of the compound represented by structural formula I to the hydroxyl protecting agent is 1:2-4, preferably 1:3; the molar ratio of the compound represented by structural formula I to the acid catalyst is 10:0.5-2, preferably 10:

1.

6. A novel method for synthesizing 3'-methoxy nucleosides according to any one of claims 1 to 5, characterized in that: In step S2, the alkali metal methanol salt is at least one of sodium methanolate, potassium methanolate or lithium methanolate; Preferably, the solvent for the methoxy nucleophilic substitution reaction is at least one of methanol, toluene, acetonitrile, tetrahydrofuran, N,N-dimethylformamide, dimethyl sulfoxide or 1,4-dioxane; Preferably, the temperature of the methoxy nucleophilic substitution reaction is 25-35° C. and the time is 6-12 h.

7. The novel method for synthesizing 3'-methoxy nucleosides according to claim 6, characterized in that: The molar ratio of the compound represented by structural formula II to the alkali metal salt of methanol is 1:1-3, preferably 1:

2.

8. A novel method for synthesizing 3'-methoxy nucleosides according to any one of claims 1 to 7, characterized in that: In step S3, the hydroxyl deprotection reaction is carried out under the reaction conditions of an acid catalyst and an alcohol solvent; Preferably, the acid catalyst is at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, methanesulfonic acid or p-toluenesulfonic acid; Preferably, the alcohol solvent is at least one of methanol, ethanol or isopropanol; Preferably, the temperature of the hydroxyl deprotection reaction is 25-35°C and the time is 6-12h; Preferably, the molar ratio of the compound represented by structural formula III to the acid catalyst is 10:0.5-2, preferably 10:

1.

9. A novel method for synthesizing 3'-methoxy nucleosides according to any one of claims 1 to 8, characterized in that: The 3'-methoxy nucleoside is 3'-methoxyadenine nucleoside, and its synthesis route is as follows:

10. A novel method for synthesizing 3'-methoxy nucleosides according to any one of claims 1 to 8, characterized in that: The 3'-methoxy nucleoside is 3'-methoxyguanosine nucleoside, and its synthesis route is as follows:

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