WO2023103306A1

WO2023103306A1 - Method for preparing deuterated cytidine derivative

Info

Publication number: WO2023103306A1
Application number: PCT/CN2022/097264
Authority: WO
Inventors: 黄才古; 黄铁强; 白礼斌
Original assignee: 广州谷森制药有限公司
Priority date: 2021-12-06
Filing date: 2022-06-07
Publication date: 2023-06-15
Also published as: CN116217632A

Abstract

The present invention relates to a method for preparing deuterated cytidine derivative 25. The method has mild reaction routes and conditions, a high conversion rate and selectivity, a high reaction yield and reaction efficiency, low energy consumption, convenient post-treatment and a simple reaction operation, and is more suitable for industrial production. According to the present invention, the deuterated cytidine derivative 25 can be prepared with a high yield which can reach more than 80%, and the purity of the product can reach more than 99%, thus reaching pharmaceutical grade.

Description

A kind of preparation method of deuterated cytidine derivative

technical field

The invention belongs to the field of drug synthesis, and in particular relates to a synthesis method of deuterated cytidine derivative 25.

Background technique

Deuterated cytidine derivative 25 is a small molecule neocytidine oral antiviral drug independently developed by Shanghai Gusen Pharmaceutical Co., Ltd. The drug is a SARS-CoV-2 polymerase inhibitor. In vitro experiments have confirmed that it has strong anti-SARS-CoV-2 activity and can effectively inhibit virus replication. The team believes that if 25 achieves similar results in human trials, COVID-19 patients treated with the oral drug could become non-infectious within a day. At present, Shanghai Gusen Pharmaceutical Co., Ltd. is preparing to conduct clinical trials for the treatment of patients with the new coronavirus. Once successful, the market prospect is very huge.

The chemical name of deuterated cytidine derivative 25 is: ((2R,3S,4R,5R)-3,4-dihydroxy-5-(4-(hydroxylamino)-2-oxopyrimidine-1(2H) -yl) tetrahydrofuran-2-yl) deuterium methyl isobutyl ester, its chemical formula is as follows:

The applicant’s previous patent CN2021110245289 reported deuterated cytidine derivative 25 and its synthetic route. Using deuterated uridine as the starting material, the dihydroxyl group was first protected by acetonylidene, and then the esterification reaction was completed with isobutyric anhydride, followed by The 1,2,4-triazole was condensed under the action of phosphorus oxychloride, then reacted with hydroxylamine, and finally the acetonylidene was removed by acidolysis to obtain the final product 25. The route looks like this:

The above route failed to provide the starting material preparation method and the yield of each step. After repeating, it was found that most of the steps required column purification, and the yield was low, which was not suitable for scale-up production. Due to production needs, it was optimized on the basis of this route.

Contents of the invention

Based on this, the present invention provides a method for preparing deuterated cytidine derivative 25. The preparation process of the present invention is simple, low in cost, high in yield and purity, and suitable for industrial production.

The specific technical scheme is as follows:

A synthetic method of deuterated cytidine derivative 25, comprising the following steps:

(1) In acetone, uridine undergoes an upprotection reaction in the presence of acid to obtain compound 25-1;

(2) In an organic solvent, add an oxidizing agent to oxidize the compound 25-1 to obtain the compound 25-2;

(3) In an organic solvent, add a deuterium reagent to deuterate the compound 25-2 to obtain compound 25-3;

(4) In an organic solvent, the compound 25-3 is reacted with an esterification reagent in the presence of a catalyst to obtain the compound 25-4;

(5) In an organic solvent, the compound 25-4 is reacted with triazole under the action of POCl ₃ /TEA to obtain the compound 25-5;

(6) In an organic solvent, the compound 25-5 is reacted with hydroxylamine to obtain compound 25-6;

(7) In an organic solvent, the compound 25-6 is reacted with an acid to obtain compound 25;

The reaction scheme is as follows:

In some of these embodiments, the acid in step (1) is selected from at least one of sulfuric acid, hydrochloric acid, nitric acid, and HBr, preferably sulfuric acid.

In some of these embodiments, the organic solvents described in steps (2) to (7) include dichloromethane, chloroform, toluene, isopropanol, methanol, ethanol, methyl tert-butyl ether, ethyl acetate, 1,4 - at least one of dioxanes.

In some of these embodiments, the oxidizing agent in step (2) includes at least one of IBX and Dess-Martin reagent; the reaction temperature is 0-100°C.

In some embodiments, the deuterium reagent in step (3) includes at least one of NaBD ₄ , LiAlD ₄ , NaD, D ₂ , and BD ₃ ; the reaction temperature is -10-100°C.

In some of these embodiments, the molar ratio of the compound 25-2 and the deuterated reagent in step (3) is 1:(1-4), preferably 1:1, 1:1.05, 1:2.

In some of these embodiments, the esterification reagent in step (4) includes at least one of isobutyryl chloride and isobutyric anhydride, preferably isobutyric anhydride; the catalyst is TEA/DMAP; and the reaction temperature is 0-100°C.

In some of these embodiments, the molar ratio of the compound 25-3 and the esterification reagent in step (4) is 1:(1-3), preferably 1:1.1.

In some of these embodiments, the acid in step (7) includes at least one of trifluoroacetic acid and formic acid; the reaction temperature is 0-100°C.

The preparation route of deuterated cytidine derivative 25 of the present invention has the following advantages and beneficial effects:

(1) The present invention provides a synthetic method of a class of neocytidine antiviral compounds, which have excellent anti-new coronavirus activity;

(2) In the present invention, the reaction conversion rate and selectivity are high, which greatly improves the reaction yield and reduces the cost;

(3) In the present invention, the reaction efficiency is high, the reaction temperature is low, multiple steps are carried out at normal temperature, the energy consumption is low, and the reaction operation is simple;

(4) The synthesis route of the present invention has mild conditions, convenient post-treatment, and is more suitable for industrial production.

Description of drawings

Fig. 1 is the NMR spectrum figure of deuterated cytidine derivative (25);

Fig. 2 is the mass spectrogram of deuterated cytidine derivative (25);

Detailed ways:

The synthesis method of the deuterated cytidine derivative 25 of the present invention will be further described in detail in conjunction with specific examples below.

The following detailed descriptions are exemplary and explanatory only, not restrictive.

In the following examples, unless otherwise indicated, all solvents and reagents used were obtained commercially and used as received.

This article uses the following abbreviations:

TEA: Triethylamine

MeCN:Acetonitrile

IBX: 2-iodoxybenzoic acid

The synthesis of embodiment 1 compound 25-1

Chemical formula: C ₁₂ H ₁₆ N ₂ O ₆

Molecular weight: 284.27

Add acetone (7.5L) and uridine (300g) into a 50L reactor, stir evenly, add concentrated sulfuric acid (240g), react at room temperature for 3 hours, and the reaction ends.

Cool down to 10°C, add ammonia water (600ml) dropwise, a large amount of solids are precipitated, filter off the solids, concentrate the solvent from the mother liquor under reduced pressure, add ethyl acetate (2.5L), add water (500ml), stir well, then let stand to separate the liquid , to collect the organic phase. The aqueous phase was extracted with ethyl acetate (2 L), and the combined organic phases were washed with saturated brine (50 ml), dried over anhydrous sodium sulfate (50 g), filtered, and the filtrate was concentrated to solvent.

Add n-hexane (2.5 L) to the concentrate, stir at room temperature to disperse and precipitate solids, stir for 1 hour, filter, and dry the wet product at 50°C for 10 hours to obtain 300 g of white powder (yield 86%, purity 99%), which is the compound 25-1.

The synthesis of embodiment 2 compound 25-2

Chemical formula: C ₁₂ H ₁₄ N ₂ O ₆

Molecular weight: 282.25

Acetonitrile (6.0 L) and compound 25-1 (300 g, 1.055 mol) were added into a 10 L reactor, IBX (886 g, 3.165 mol) was added, the temperature was raised to 80° C. for 3 hours, and the reaction was completed.

Cool down to room temperature, remove the solid by filtration, and concentrate the filtrate to remove the solvent to obtain compound 25-2 (purity 90%). The compound was directly subjected to the next reaction without further purification.

By replacing the IBX in Example 2 with the Dess-Martin reagent, 25-2 (purity ≥ 90%) can also be successfully prepared.

The synthesis of embodiment 3 compound 25-3

Chemical formula: C ₁₂ H ₁₅ DN ₂ O ₆

Molecular weight: 285.27

Add deuterated ethanol (3.0L) and the previous step compound 25-2 concentrate (1.055mol) into a 10L reactor, stir to dissolve and cool down to 0°C, add sodium borodeuteride (44.2g, 1.055mol) in batches ), after the addition, the temperature was raised to room temperature for 1 hour, and the reaction ended.

Add water (50ml) to quench, stir well and then concentrate the solvent. Ethyl acetate (6.0 L) was added, water (100 ml) was added, after stirring evenly, the mixture was allowed to stand for liquid separation, and the organic phase was collected. The aqueous phase was extracted with ethyl acetate (3.0 L), the combined organic phases were washed with saturated brine (150 ml), dried over anhydrous sodium sulfate (100 g), filtered, and the solvent was concentrated.

Add n-hexane (3.0 L) to the concentrate, stir at room temperature for 2 hours, filter, and dry the wet product under vacuum at 50°C to obtain compound 25-3 as 250 g of white powder with a purity of 99% and a two-step yield of 83%.

Ms m/z:284[MH] ^- ;

¹ H-NMR(500MHz,DMSO-d6)δ:ppm 11.34(1H,s), 7.78(1H,d), 5.83(1H,d), 5.62～5.64(1H,m), 5.04(1H,br) ,4.88～4.90(1H,m),4.73～4.75(1H,m),4.05～4.07(1H,m),3.53～3.57(1H,m),1.48(3H,s),1.29(3H,s) .

By replacing sodium borodeuteride in Example 3 with at least one of LiAlD ₄ , NaD, D ₂ and BD ₃ , 25-3 can also be successfully prepared with a purity of 95-99% and a yield of 50-80%.

The synthesis of embodiment 4 compound 25-4

Chemical formula: C ₁₆ H ₂₁ DN ₂ O ₇

Molecular weight: 355.37

Acetone (6.25L) was added to a 10-liter reactor, compound 25-3 (250g, 0.876mol) was added, and triethylamine (443g, 4.38mol) and DMAP (5.35g, 0.0438mol) were added after stirring to dissolve, and stirred dissolve clear. The temperature was lowered to below 10°C, and isobutyric anhydride (152 g, 0.96 mol) was added dropwise, and the mixture was raised to room temperature to react for 6 hours, and the reaction ended.

Concentrate the solvent under reduced pressure, add ethyl acetate (3 L) to dissolve, first wash with 10% citric acid aqueous solution (500ml), then with saturated sodium carbonate solution (500ml), then with water (500ml), and finally with saturated brine ( 500ml) was washed, dried over anhydrous sodium sulfate (100g), filtered, and the solvent was concentrated to obtain compound 25-4 as 280g of light yellow liquid with a purity of 98.5% and a yield of 90%.

Ms m/z:356[M+H ⁺ ];

¹ H-NMR(500MHz,DMSO-d6)δ:ppm 11.34(1H,s), 7.68(1H,d), 5.79(1H,d), 5.62～5.64(1H,m), 5.03～5.05(1H, m), 4.79(1H,m), 4.17～4.22(2H,m), 2.50～2.56(1H,m), 1.48(3H,s), 1.29(3H,s), 1.08(6H,d).

By replacing the isobutyric anhydride in Example 4 with isobutyryl chloride, 25-4 can also be successfully prepared with a purity of 97.5% and a yield of 85%.

The synthesis of embodiment 5 compound 25-5

Chemical formula: C ₁₈ H ₂₂ DN ₅ O ₆

Molecular weight: 406.42

Acetonitrile (2.8L) was added to a 10-liter reactor, compound 25-4 (280g, 0.788mol) was added, and triethylamine (638g, 6.304mol) and 1,2,4-triazole (392g , 5.67mol), stirred and dissolved. The temperature was lowered to 0°C, phosphorus oxychloride (181 g, 1.182 mol) was slowly added dropwise, and the reaction was completed at room temperature for 1 hour after the dropwise completion.

After quenching by adding water (1.4L) dropwise, the solvent was concentrated under reduced pressure, ethyl acetate (2.8L) was added, stirred thoroughly and left to separate liquids, the organic phase was collected, washed with water (1.4L), and then washed with saturated brine (1.4L) L) washing, drying over anhydrous sodium sulfate (100 g), filtering, and concentrating the solvent to obtain compound 25-5 as 300 g of light yellow liquid with a purity of 98.3% and a yield of 94%.

Ms m/z:407[M+H ⁺ ];

¹ H-NMR (500MHz, DMSO-d6) δ:ppm 9.45(1H,s), 8.47(1H,d), 8.41(1H,s), 6.99(1H,d), 5.90(1H,d), 5.06 ～5.08(1H,m), 4.83(1H,m), 4.45(1H,m), 4.24～4.30(1H,m), 2.44～2.50(1H,m), 1.51(3H,s), 1.32(3H ,s), 1.02(6H,d).

The synthesis of embodiment 6 compound 25-6

Chemical formula: C ₁₆ H ₂₂ DN ₃ O ₇

Molecular weight: 370.38

Add isopropanol (6L) to a 10-liter reactor, add compound 25-5 (300g, 0.738mol), stir to dissolve, add 50% hydroxylamine aqueous solution (73g, 1.11mol), react at room temperature for 4 hours, and the reaction is complete.

The solvent was concentrated under reduced pressure, ethyl acetate (6 L) was added, water (3 L) was added, the liquid was separated after being fully stirred, the organic phase was collected, washed with water (1.5 L), and then washed with saturated brine (1.5 L), and no Dry over sodium sulfate (100 g), filter, and concentrate the solvent to obtain compound 25-6 as 270 g of light yellow liquid with a purity of 99.1% and a yield of 98%.

Ms m/z:371[M+H ⁺ ];

¹ H-NMR(500MHz,DMSO-d6)δ:ppm 10.03(1H,s), 9.60(1H,s), 6.87(1H,d), 5.71(1H,d), 5.55～5.57(1H,m) ,4.94～4.95(1H,m),4.76(1H,m),4.11～4.13(1H,m),2.49～2.51(1H,m),1.48(3H,s),1.29(3H,s),1.09 (6H,d).

The synthesis of embodiment 7 compound 25

Chemical formula: C ₁₃ H ₁₈ DN ₃ O ₇

Molecular weight: 330.32

Add trifluoroacetic acid (2.7 L) into a 10-liter reactor, add compound 25-6 (270 g, 0.73 mol), stir to dissolve, react at room temperature for 10 hours, and the reaction ends.

The solvent was concentrated under reduced pressure, then strip-dried with ethanol (1 L) and then strip-dried with ethanol (1 L) to give a reddish-brown oil.

Add isopropanol (300ml), stir and disperse, add methyl tert-butyl ether (3L), raise the temperature to 60°C, stir until a solid precipitates, continue stirring for 1 hour, cool down to room temperature, keep warm for 1 hour, and filter. The wet product was vacuum-dried at 50°C for 16 hours to obtain compound 25 as a white powder, weighing 200 g, with a purity of 99.7% and a yield of 83%.

Ms m/z:331[M+H ⁺ ];

¹ H-NMR (500MHz, DMSO-d6) δ:ppm 9.99(1H,s), 9.47(1H,s), 6.82(1H,d), 5.71(1H,d), 5.58(1H,d), 5.18 ～5.32(2H,br), 4.11～4.20(1H,m), 4.00(1H,m), 3.91～3.92(2H,m), 2.50～2.60(1H,m), 1.10(6H,d).

By replacing the trifluoroacetic acid in Example 7 with formic acid, 25 can also be successfully prepared with a purity of 98.5% and a yield of 80%.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims

A method for synthesizing deuterated cytidine derivatives (25), comprising the following steps:

(1) In acetone, uridine undergoes an upprotection reaction in the presence of acid to obtain compound 25-1;

(2) In an organic solvent, add an oxidizing agent to oxidize the compound 25-1 to obtain the compound 25-2;

(3) In an organic solvent, add a deuterium reagent to deuterate the compound 25-2 to obtain compound 25-3;

(4) In an organic solvent, the compound 25-3 is reacted with an esterification reagent in the presence of a catalyst to obtain the compound 25-4;

(5) In an organic solvent, the compound 25-4 is reacted with triazole under the action of POCl 3 /TEA to obtain the compound 25-5;

(6) In an organic solvent, the compound 25-5 is reacted with hydroxylamine to obtain compound 25-6;

(7) In an organic solvent, the compound 25-6 is reacted with an acid to obtain compound 25;

The reaction scheme is as follows:
The method for synthesizing deuterated cytidine derivatives (25) according to claim 1, characterized in that: the acid in step (1) is selected from at least one of sulfuric acid, hydrochloric acid, nitric acid, and HBr.
The method for synthesizing deuterated cytidine derivatives (25) according to claim 1-2, characterized in that: the acid in step (1) is selected from sulfuric acid.
The synthesis method of deuterated cytidine derivatives (25) according to any one of claims 1-2, characterized in that: the organic solvent in steps (2) to (7) is selected from dichloromethane, chloroform, toluene , isopropanol, methanol, ethanol, methyl tert-butyl ether, ethyl acetate, and 1,4-dioxane.
The synthetic method of the deuterated cytidine derivative (25) according to any one of claims 1-2, characterized in that: the oxidant in step (2) is selected from at least one of IBX and Dess-Martin reagent species; the reaction temperature is 0-100°C.
The method for synthesizing deuterated cytidine derivatives (25) according to any one of claims 1-2, characterized in that: the deuterated reagent in step (3) is selected from NaBD 4 , LiAlD 4 , NaD, D 2 , at least one of BD 3 ; the reaction temperature is -10-100°C.
According to the synthetic method of deuterated cytidine derivative (25) described in any one of claim 1-2, it is characterized in that: the molar ratio of compound 25-2 described in step (3) and deuterated reagent is 1: (1~4).
According to the synthetic method of the deuterated cytidine derivative (25) described in any one of claims 1-2, it is characterized in that: the esterification reagent described in step (4) is selected from at least one of isobutyryl chloride and isobutyric anhydride species; the catalyst is TEA/DMAP; the reaction temperature is 0-100°C.
According to the synthetic method of deuterated cytidine derivative (25) described in any one of claim 1-2, it is characterized in that: the molar ratio of compound 25-3 and esterification reagent described in step (4) is 1: (1~3).
According to the synthetic method of deuterated cytidine derivative (25) described in any one of claim 1-2, it is characterized in that: the acid described in step (7) is selected from at least one in trifluoroacetic acid, formic acid; Reaction temperature 0 to 100°C.