Preparation method of galisvir and galisvir intermediate and corresponding galisvir intermediate

Abstract

The present invention belongs to the technical field of preparation of bulk drug intermediates, and discloses a preparation method of galisvir and a galisvir intermediate and a corresponding galisvir intermediate. The preparation method of galisvir comprises the following steps: 1) compound 10 reacts with benzophenone imine under alkaline conditions to obtain compound 11; 2) compound 11 is hydrolyzed to obtain compound 12; 3) compound 12 is reacted under acidic conditions to obtain galisvir. The present invention provides a preparation method of galisvir, which has few by-products, high yield and purity, and can meet the industrial production requirements of galisvir. In addition, the present invention provides a preparation method of a new galisvir intermediate and a corresponding galisvir intermediate, which provides a new idea for the preparation of galisvir.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of raw materials and intermediates thereof, and in particular relates to a preparation method of galisvir and a galisvir intermediate and a corresponding galisvir intermediate. Background Art

[0002] Galidesivir (Cas No. 249503-25-1, also known as Galidesivir, BCX4430 or Immucillin-A) is a new anti-Ebola virus drug developed by Biocryst Pharmaceuticals in the United States. It can effectively inhibit the activity of RNA polymerase and act as a non-specific RNA chain termination codon. Its structure is as follows:

[0003]

[0004] As an adenosine analog and direct-acting antiviral drug, it can directly destroy the viral RNA-dependent RNA polymerase (RdRp) and thus exhibit antiviral activity, with broad activity against multiple different families of RNA viruses in cell culture. This activity has also been shown in animal models of viral diseases related to Ebola virus, Marburg virus, yellow fever, Zika virus and Rift Valley fever virus.

[0005] The preparation method of galisvir has been reported in the prior art, and the process reported in the literature is as follows:

[0006] Route 1:

[0007]

[0008] Route 1 uses cheap and readily available D-ribose as the starting material, and the synthetic route adopts a convergent synthesis method. This design idea is very practical, but this route also has many shortcomings. First, the yield of dibenzylamine replacing the pyrrolopyrimidine ring is not very ideal; second, in the process of synthesizing the tetrahydropyrrole ring from the dicarbonyl ring, sodium cyanoborohydride, which is highly toxic and expensive, is used, thus limiting the industrial application of this route.

[0009] Route 2:

[0010]

[0011] Route 2 uses relatively expensive D-(-)-gulonic acid-gamma-lactone as the starting material, which increases the production cost. In addition, when acetic acid is used to selectively remove the acetone protection in the fifth step, it will inevitably cause the hydrolysis of another ketal, which brings many difficulties to the subsequent steps.

[0012] In addition, CN104379146B discloses:

[0013] Process 28

[0014]

[0015] CN104513249B discloses:

[0016]

[0017] The journal article ("Synthesis of Immucillins BCX-1777and BCX-4430from a Common Precursor", KAKrishnakumar et al., "Eur. J. Org. Chem", 2022, e202200428) disclosed:

[0018]

[0019] However, in the prior art, the preparation method of galisvir has the problems of expensive starting materials, many side reactions, complicated purification process, low yield, low purity, etc., which makes it difficult to realize the industrial production of galisvir.

[0020] Therefore, it is necessary to provide a new preparation method of galisvir, which has few by-products, high yield and purity, can meet the requirements of industrial production of galisvir, and provide a new idea for the industrial production of galisvir. Summary of the invention

[0021] The present invention aims at the problems existing in the prior art and provides a preparation method of galisvir and a galisvir intermediate and a corresponding galisvir intermediate. The method has few by-products, high yield and purity, and can meet the industrial production requirements of galisvir.

[0022] In order to achieve the above objectives, in a first aspect, the present invention provides a method for preparing galisvir, wherein the galisvir has the following structural formula:

[0023]

[0024] The preparation method comprises the following steps:

[0025] 1) Compound 10 reacts with benzophenone imine under alkaline conditions to obtain compound 11;

[0026] 2) Compound 11 is hydrolyzed to obtain compound 12;

[0027] 3) Compound 12 is reacted under acidic conditions to obtain galisvir;

[0028]

[0029] In a preferred embodiment, in step I), the molar ratio of compound 10 to benzophenone imine is 1:1-2; and the reaction conditions are 90-110° C. for 8-15 h.

[0030] In a preferred embodiment, in step I), the solvent is dioxane, the catalyst is a mixture of tris(dibenzylideneacetone)dipalladium and 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene, and alkalinity is provided by potassium carbonate; the mass volume ratio of compound 10 to the solvent is 1 g:(10-30) mL, the molar ratio of compound 10 to the catalyst is 2-10:1, and the molar ratio of compound 10 to potassium carbonate is 1:2-3.

[0031] In a preferred embodiment, in step I), the catalyst is tris(dibenzylideneacetone)dipalladium and 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene in a molar ratio of 1:0.8-1.5, and more preferably tris(dibenzylideneacetone)dipalladium and 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene in a molar ratio of 1:1.

[0032] In a preferred embodiment, in step II), the solvent is alcohol, the catalyst is potassium carbonate; the mass volume ratio of compound 11 to the solvent is 1 g:(15-40) mL, and the mass ratio of compound 11 to the catalyst is 1:0.5-2; the reaction conditions are reaction at room temperature for 10-60 min.

[0033] In a preferred embodiment, in step II), the alcohol is selected from at least one of methanol, ethanol, propanol and n-butanol.

[0034] In a preferred embodiment, in step III), the solvent is water, and the acidity is provided by concentrated acid; the mass volume ratio of compound 12 to water is 1 g:(30-80) mL, and the mass volume ratio of compound 12 to concentrated acid is 1 g:(40-80) mL; the reaction conditions are reaction at room temperature for 30-90 min.

[0035] In a preferred embodiment, in step III), the concentrated acid is selected from concentrated hydrochloric acid, concentrated sulfuric acid and concentrated nitric acid with a molar concentration of 8-15M.

[0036] In a preferred embodiment, the preparation of compound 10 comprises the following steps:

[0037] 1) Compound 7 is hydrolyzed under acidic conditions to obtain compound 8;

[0038] 2) Compound 8 reacts with Boc anhydride and acetic anhydride in sequence to obtain compound 9;

[0039] 3) Compound 9 reacts with a chlorination agent to obtain the galisvir intermediate compound 10;

[0040]

[0041] In a preferred embodiment, alcohol is used as a solvent in step 1), and the mass volume of compound 7 and alcohol is (0.5-5) g / 10 mL; the alcohol is selected from methanol, ethanol, propanol or n-butanol; concentrated acid is used to provide acidity in step 1), the concentration of the concentrated acid is 10-15 M, and the volume mass ratio of the concentrated acid to compound 7 is (10-30) mL:1 g; the concentrated acid is selected from concentrated hydrochloric acid and / or concentrated sulfuric acid.

[0042] In a preferred embodiment, the hydrolysis reaction conditions are: 70-90° C. for 8-15 h.

[0043] In a preferred embodiment, in step 2), compound 8 is reacted with Boc anhydride to obtain rac-(2R,3R,4S,5S)-3,4-dihydroxy-2-(hydroxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate, and rac-(2R,3R,4S,5S)-3,4-dihydroxy-2-(hydroxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate is reacted with acetic anhydride to obtain compound 9.

[0044] In a preferred embodiment, in step 2), the molar ratio of compound 8 to Boc anhydride is 1:1-5; the molar ratio of compound 8 to acetic anhydride is 1:2-6.

[0045] In a preferred embodiment, in step 2), solvent 1 and catalyst 1 are used for the reaction of compound 8 with Boc anhydride, the mass volume ratio of compound 8 to solvent 1 is 1 g:(50-100) mL, and the mass ratio of compound 8 to catalyst 1 is 1:0.5-3; the solvent 1 is selected from at least one of methanol, ethanol, propanol, n-butanol and water; and the catalyst 1 is triethylamine.

[0046] In a preferred embodiment, in step 2), the reaction conditions of compound 8 and Boc anhydride are: reaction at room temperature for 20-60 min.

[0047] In a preferred embodiment, in step 2), rac-(2R,3R,4S,5S)-3,4-dihydroxy-2-

[0048] When (hydroxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate reacts with acetic anhydride, solvent 2 and catalyst 2 are used, and the volume mass ratio of solvent 2 to compound 8 is (1-5) mL:1 g; the molar ratio of compound 8 to catalyst 2 is 1:0.005-0.05; the solvent 2 is pyridine, and the catalyst 2 is DMAP.

[0049] In a preferred embodiment, in step 2), rac-(2R,3R,4S,5S)-3,4-dihydroxy-2-

[0050] The reaction conditions of (hydroxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate and acetic anhydride are: reaction at room temperature for 8-15 hours.

[0051] In a preferred embodiment, in step 3), the chlorination agent is selected from benzyl (triethyl) ammonium chloride; the molar ratio of compound 9 to the chlorination agent is 1:1-4; and the reaction conditions are 70-90°C for 5-30 min.

[0052] In a preferred embodiment, in step 3), solvent 3 and catalyst 3 are used when compound 9 reacts with a chlorinating agent, the mass volume ratio of compound 9 to solvent 3 is 1 g:(30-100) mL, and the molar ratio of compound 9 to catalyst 3 is 1:5-10; the solvent 3 is acetonitrile; the catalyst 2 is N,N-dimethylaniline and / or phosphorus oxychloride; more preferably, a mixture of N,N-dimethylaniline and phosphorus oxychloride, the molar ratio of the two is 1:3-5.

[0053] In a preferred embodiment, the preparation of compound 7 comprises the following steps:

[0054]

[0055] In a preferred embodiment, in step S1, anhydrous methyl tert-butyl ether and anisole in a volume ratio of 2-4:1 are used as solvent, and a molar concentration of 1-4M n-butyl lithium tetrahydrofuran solution is used as catalyst; the mass volume ratio of compound 3 to solvent is 1 g: (15-30) mL, and the mass volume ratio of compound 3 to catalyst is 1 g: (1.5-2) mL; the molar ratio of compound 3 to compound R02 is 1: 1-2; and the reaction conditions are -78°C for 1-3h.

[0056] In a preferred embodiment, in step S2, ethanol is used as the solvent and sodium borohydride is used as the catalyst; the mass volume ratio of compound 4 to the solvent is 1 g:(5-15) mL, and the molar ratio of compound 4 to the catalyst is 1:0.8-1.5; the reaction conditions are room temperature for 30-120 min.

[0057] In a preferred embodiment, in step S3, dimethyl sulfoxide is used as the solvent and 2-iodoacylbenzoic acid is used as the catalyst; the mass volume ratio of compound 5 to the solvent is 1 g:(5-15) mL, and the molar ratio of compound 5 to the catalyst is 1:4-8; the reaction conditions are 35-40° C. for 8-15 h.

[0058] In a preferred embodiment, in step S4, ethanol is used as the solvent, and 4AMS, ammonium formate and sodium cyanoborohydride in a mass ratio of 1-2:1-2:1 are used as catalysts; the mass volume ratio of compound 6 to the solvent is 1 g:(5-15) mL, and the mass ratio of compound 6 to the catalyst is 1:2-4; the reaction conditions are reaction at room temperature for 20-40 min.

[0059] In a preferred embodiment, the preparation of compound 3 comprises the following steps:

[0060]

[0061] In a preferred embodiment, in step A, tetrahydrofuran is used as the solvent and sodium hydride is used as the catalyst; the mass volume ratio of compound 1 to the solvent is 1 g:(10-20) mL, the molar ratio of compound 1 to the catalyst is 1:1-3; the molar ratio of compound 1 to compound R01 is 1:1-2; and the reaction conditions are -10-10°C for 1-4h.

[0062] In a preferred embodiment, in step B, methanol is used as the solvent and sodium methoxide is used as the catalyst; the mass volume ratio of compound 2 to the solvent is 1 g:(5-20) mL, and the molar ratio of compound 2 to the catalyst is 1:1-2; the reaction conditions are reaction at room temperature for 2-6 hours.

[0063] In a second aspect, the present invention provides a method for preparing a galisvir intermediate, wherein the galisvir intermediate is shown as compound 11, and the preparation method thereof comprises:

[0064]

[0065] In a third aspect, the present invention provides a method for preparing a galisvir intermediate, wherein the galisvir intermediate is shown as compound 12, and the preparation method thereof comprises:

[0066]

[0067] In a fourth aspect, the present invention provides a galisvir intermediate prepared by the preparation method of the aforementioned galisvir intermediate.

[0068] Compared with the prior art, the present invention has the following beneficial effects:

[0069] 1. The present invention provides a method for preparing galisvir, which has few by-products, high yield and purity, and can meet the requirements for industrial production of galisvir.

[0070] 2. The present invention provides a new preparation method of a galisvir intermediate and a corresponding galisvir intermediate, providing a new idea for the preparation of galisvir. DETAILED DESCRIPTION

[0071] It is worth noting that the raw materials used in the present invention are all common commercially available products, and their sources are not specifically limited.

[0072] The synthetic route of galisvir is as follows:

[0073]

[0074] Example 1 Step 1: Synthesis of Compound 2

[0075] Sodium hydride (12.0 g, 0.30 mol, 60% mineral oil) and chloromethoxytoluene (43.8 g, 0.28 mol) were added to a tetrahydrofuran solution of 7-bromo-4-chloro-5H-pyrrolo[3,2-d]pyrimidine (50 g, 0.21 mol) (800 mL) at 0°C. The reaction solution was stirred at 0°C for 2 h. The reaction was quenched with pure water (500 mL), and the aqueous phase was extracted with ethyl acetate (500 mL×3). The combined organic phase was washed with brine (500 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to obtain the compound 5-(benzyloxymethyl)-7-bromo-4-chloro-pyrrolo[3,2-d]pyrimidine (75 g, purity 90%, yield 89%) as a light yellow solid. It was used directly in the next step. MS (ESI) M / Z: 351.9 / 353.9 [M+H] + .

[0076] Example 2 Step 2: Synthesis of Compound 3

[0077] Solid sodium methoxide (46.0 g, 0.25 mol) was added in batches to a methanol solution (800 mL) of 5-(benzyloxymethyl)-7-bromo-4-chloro-pyrrolo[3,2-d]pyrimidine (75 g, 0.21 mol). The reaction solution was stirred at 25°C for 4 h. The reaction mixture was cooled to 0°C, quenched with pure water (800 mL), and the aqueous phase was extracted with ethyl acetate (800 mL×3). The combined organic phase was washed with brine (800 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by slurrying with a mixed solution of petroleum ether and methyl tert-butyl ether (10:1, 800 mL) to obtain compound 5-(benzyloxymethyl)-7-bromo-4-methoxy-pyrrolo[3,2-d]pyrimidine (43 g, purity 91.6%, yield 53.13%) as a light yellow solid.

[0078] MS (ESI) M / Z: 347.9 / 349.9 [M+H] + .

[0079] 1 H NMR: ET86557-11-P1A;

[0080] 1 H NMR (DMSO-d6, 400MHz) δ8.51(s,1H),8.13(s,1H),7.36-7.17(m,5H),5.74(s,2H),4.52(s,2H),4.07(s,3H).

[0081] Example 3 Step 3: Synthesis of Compound 4

[0082] 5-(Benzyloxymethyl)-7-bromo-4-methoxy-pyrrolo[3,2-d]pyrimidine solution (43 g, 0.12 mol) was dissolved in anhydrous methyl tert-butyl ether (600 mL) and anisole (200 mL) and cooled to -78°C. n-BuLi (2.5 M tetrahydrofuran solution, 74 mL) was added dropwise under nitrogen and stirred for 0.5 h. Then, rac-(3aR,6aR)-6-[[tert-butyl(dimethyl)silyl]oxymethyl]-2,2-dimethyl-6,6a-dihydro-3aH-furan[3,4-d][1,3]dioxo-4-one (44.8 g, 0.15 mol) in methyl tert-butyl ether (300 mL) was added dropwise to the above mixture. After the addition was complete, the reaction solution was stirred at -78°C for 2 h. The reaction was quenched with saturated aqueous ammonium chloride (1.8 L). The aqueous phase was extracted with ethyl acetate (800 mL x 3). The combined organic phase was washed with brine (800 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified by flash silica gel chromatography ( 120 The product was purified by silica gel flash column, 0-100% ethyl acetate / petroleum ether gradient elution, 80 mL / min) to give the compound [5-(benzyloxymethyl)-4-methoxy-pyrrolo[3,2-d]pyrimidin-7-yl]-[racemic-(4R,5R)-5-[2-[tert-butyl(dimethyl)silyl]oxo-1-hydroxy-ethyl]-2,2-dimethyl-1,3-dioxolan-4-yl]methanone (24 g, purity 80%, yield 27.2%) as a light yellow oil.

[0083] MS (ESI) M / Z: 572.3 [M+H] + .

[0084] 1 H NMR: ET86557-51-P1A;

[0085] 1 H NMR(DMSO-d6,400MHz)δ8.46(s,1H),7.81(s,1H),7.36-7.21(m,5H),5.75(s,2H),4.75-4.62(m,1H),4 .45(s,2H),4.10-3.99(m,2H),3.70-3.65(m,1H),1.20(s,3H),1.17(s,3H),0.90(s,9H),0.09(s,6H).

[0086] Condition optimization:

[0087]

[0088]

[0089] It can be seen that in the preparation process of compound 4, the reaction solvent and reaction temperature have a very large influence on whether the target product compound 4 can be prepared. Using methyl tert-butyl ether / anisole as a solvent, compound 4 with higher purity can be prepared at -78°C.

[0090] Example 4 Step 4: Synthesis of Compound 5

[0091] To an ethanol solution (100 mL) of [5-(benzyloxymethyl)-4-methoxy-pyrrolo[3,2-d]pyrimidin-7-yl]-[racemic-(4R,5R)-5-[2-[tert-butyl(dimethyl)silyl]oxo-1-hydroxy-ethyl]-2,2-dimethyl-1,3-dioxacyclic-4-yl]methanone (10 g, 17 mmol) was added sodium borohydride (0.66 g, 17 mmol) in batches at 0°C. The reaction solution was stirred at 25°C for 1 h. The reaction was quenched with pure water (100 mL), and the aqueous phase was extracted with ethyl acetate (150 mL×3). The combined organic phase was washed with brine (150 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give compound 2-[tert-butyl(dimethyl)silyl]oxo-1-[rac-(4R,5S)-5-[[5-(benzyloxymethyl)-4-methoxy-pyrrolo[3,2-d]pyrimidin-7-yl]-hydroxy-methyl]-2,2-dimethyl-1,3-dioxolan-4-yl]ethanol (9 g, purity 85%, yield 76.2%) as a colorless oil. It was used directly in the next step without purification.

[0092] MS (ESI) M / Z: 574.3 [M+H] + .

[0093] 1 H NMR(DMSO-d6,400MHz)δ8.50(s,1H),7.33-7.24(m,5H),7.06(s,1H),5.84(d,J=10.8Hz,1H), 5.67(d,J=11.0Hz,1H),5.18(dd,J=7.2,6.0Hz,1H),4.70(dt,J=11.9,0.9,0.9Hz,1H),4.60( dt,J=12.0,0.9,0.9Hz,1H),4.51(dd,J=7.2,4.8Hz,1H),4.12-4.03(m,1H),3.81-3.68(m,5H ),3.64-3.58(m,2H),3.20-3.14(m,1H),1.36(s,3H),1.25(s,3H),0.89(s,9H),0.06(s,6H).

[0094] Example 5 Step 5: Synthesis of Compound 6

[0095] 2-iodobenzoic acid (22.8 g, 81.6 mol) was added to a solution of 2-[tert-butyl(dimethyl)silyl]oxo-1-[rac-(4R,5S)-5-[[5-(benzyloxymethyl)-4-methoxy-pyrrolo[3,2-d]pyrimidin-7-yl]-hydroxy-methyl]-2,2-dimethyl-1,3-dioxolan-4-yl]ethanol (7.8 g, 13.6 mmol) in anhydrous dimethyl sulfoxide (40 mL). The reaction solution was stirred at 37°C for 12 h. The reaction was quenched with pure water (50 mL), and the aqueous phase was extracted with ethyl acetate (55 mL×3). The combined organic phases were washed with brine (55 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give compound 2-[tert-butyl(dimethyl)silyl]oxy-1-[rac-(4S,5R)-5-[5-(benzyloxymethyl)-4-methoxy-pyrrolo[3,2-d]pyrimidine-7-carbonyl]-2,2-dimethyl-1,3-dioxolan-4-yl]ethanone (7.5 g, 70% purity, 67.6% yield) as a light yellow oil.

[0096] MS (ESI) M / Z: 570.2 [M+H] + .

[0097] 1 H NMR: ET88364-6-P1A;

[0098] 1 H NMR(DMSO-d6,400MHz)δ8.64(s,1H),8.62(s,1H),7.25-7.21(m,5H),6.22(d,J=7.6Hz,1H),5.83(s,2H),5.14(d,J=7.2Hz,1H),4 .54(s,2H),4.43(s,2H),4.09(s,3H),4.05(d,J=2.0Hz,1H),1.47(s,3H),1.42(s,3H),0.75(s,9H),-0.04(s,3H),-0.06(s,3H).

[0099] Example 6 Step 6: Synthesis of Compound 7

[0100] 4AMS (7.28 g), ammonium formate (7.75 g, 122 mmol) and sodium cyanoborohydride (4.71 g, 74.9 mmol) were added to a solution of 2-[tert-butyl(dimethyl)silyl]oxo-1-[rac-(4S,5R)-5-[5-(benzyloxymethyl)-4-methoxy-pyrrolo[3,2-d]pyrimidine-7-carbonyl]-2,2-dimethyl-1,3-dioxetan-4-yl]ethanone (7.28 g, 12.8 mmol) in ethanol (100 mL) respectively. The reaction mixture was stirred at 25°C for 30 minutes. The reaction mixture was filtered, and pure water (80 mL) and EtOAc (100 mL) were added to the filtrate. The mixture was poured into a separatory funnel and separated. The aqueous phase was extracted with ethyl acetate (100 mL×2). The combined organic phases were washed with brine (100 mL), dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The crude product was purified by flash silica gel chromatography ( 20 Silica gel column, eluent 0-100% ethyl acetate / petroleum ether gradient @ 45mL / min) was used for purification to obtain the compound tert-butyl-dimethyl-[[rac-(3aS,4S,6R,6aR)-4-

[0101] [5-(Benzyloxymethyl)-4-methoxy-pyrrolo[3,2-d]pyrimidin-7-yl]-2,2-dimethyl-4,5,6,6a-tetrahydro-3aH-[1,3]dioxo[4,5-c]pyrrol-6-yl]methoxy]silane (2.5 g, 90% purity, 33.0% yield) was a light yellow oil.

[0102] MS (ESI) M / Z: 555.2 [M+H] + .

[0103] 1 H NMR: ET88364-8-P1A;

[0104] 1 H NMR (CDCl3, 400MHz) δ8.45 (s, 1H), 7.64 (s, 1H), 7.45-7.22 (m, 7H), 5.91-5.61 (m, 2H), 4.95 (d, J = 4.8Hz ,3H),4.55(s,2H),4.13(s,3H),4.12-4.05(m,2H),1.45(s,3H),1.29(s,3H),0.95(s,9H),0.17(s,6H).

[0105] Example 7 Step 7: Synthesis of Compound 8

[0106] tert-butyl-dimethyl-[[rac-(3aS,4S,6R,6aR)-4-[5-(benzyloxymethyl)-4-methoxy-pyrrolo[3,2-d]pyrimidin-7-yl]-2,2-dimethyl-4,5,6,6a-tetrahydro-3aH-[1,3]dioxo[4,5-c]pyrrol-6-yl]

[0107] Concentrated hydrochloric acid (12M, 40mL) was added to a solution of]methoxysilane (2g, 0.77mmol) in methanol (10mL). The reaction mixture was stirred at 80°C for 12h. The reaction was filtered and dried, and the crude product was slurried with acetonitrile, filtered and the filter cake was collected to obtain the compound rac-(2R,3R,4S,5S)-2-(hydroxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-3,4-diol (1g, purity 90%, yield 82.5%) as a light yellow solid. It was used directly in the next step without purification.

[0108] MS (ESI) M / Z: 267.1 [M+H] + .

[0109] 1 H NMR: ET88364-9-P1A;

[0110] 1 H NMR(DMSO-d6,400MHz)δ7.98(s,1H),7.80(s,1H),4.83(d,J=4.8Hz,1H),4.43(dd ,J=4.2,7.2Hz,1H),4.24(t,J=4.4Hz,1H),3.76-3.73(m,2H),3.67-3.64(m,2H).

[0111] Example 8 Step 8: Synthesis of Compound 9

[0112] Triethylamine (1.28 g) and Boc anhydride (1.38 g, 6.34 mmol) were added to a mixed solution of rac-(2R,3R,4S,5S)-2-(hydroxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-3,4-diol (0.96 g, 3.2 mmol) in methanol (48 mL) and water (24 mL), respectively. The reaction mixture was stirred at 25°C for 30 minutes. After the reaction mixture was concentrated under reduced pressure, the crude product rac-(2R,3R,4S,5S)-3,4-dihydroxy-2-(hydroxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate was dissolved in pyridine (1.79 mL), and DMAP (7.75 mg, 63.4 μmol) and acetic anhydride (1.13 g, 11.1 mmol) were added respectively. The reaction solution was stirred at 25 ° C for 12 h. The reaction mixture was diluted with pure water (20 mL) and extracted with ethyl acetate (30 mL×3). The combined organic layer was washed with brine (35 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to obtain a residue. The crude product was purified by silica gel column chromatography to give the compound tert-butyl rac-(2R,3R,4S,5S)-3,4-diacetoxy-2-(acetoxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate (600 mg, purity 92.8%, yield 38.4%) as a white solid.

[0113] MS (ESI) M / Z: 493.2 [M+H] + .

[0114] 1 H NMR: ET88364-13-P1A;

[0115] 1 H NMR(DMSO-d6,400MHz)δ11.97(s,1H),11.82(d,J=2.4Hz,1H),7.76(d,J=3.2Hz,1H),7.19(s,1H),5.50(d,J=6.0Hz,2H) ,5.37(d,J=5.2Hz,1H),4.56-4.46(m,1H),4.37(d,J=6.4Hz,2H),2.00(d,J=7.2Hz,6H),1.75(s,3H),1.27-0.95(m,9H).

[0116] Example 9 Step 9: Synthesis of Compound 10

[0117] To a solution of tert-butyl (2R,3R,4S,5S)-3,4-diacetoxy-2-(acetoxymethyl)-5-(4-hydroxy-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate (340 mg, 690 μmol) in acetonitrile (15 mL) were added benzyl(triethyl)ammonium chloride (314 mg, 1.38 mmol), N,N-dimethylaniline (125 mg, 1.04 mmol) and phosphorus oxychloride (635 mg, 4.14 mmol) respectively, and a clear, light yellow solution was obtained after stirring. The reaction mixture was slowly heated to 80°C and the reaction was continued at this temperature for 10 minutes. After cooling to room temperature, the phosphorus oxychloride was removed by concentration under reduced pressure. The residue was quenched with warm water (10 mL), dissolved in 10 mL of chloroform, and quickly and carefully washed with saturated sodium bicarbonate aqueous solution until the pH value reached neutral. The organic layer was separated, washed with water (10 mL), brine (10 mL), dried over sodium sulfate, filtered and concentrated under reduced pressure to give the crude product. The residue was purified by silica gel column, 0-100% ethyl acetate / petroleum ether gradient elution, 35 mL / min) to obtain the compound tert-butyl (2R, 3R, 4S, 5S)-3,4-diacetoxy-2-(acetoxymethyl)-5-

[0118] (4-Chloro-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate (110 mg, purity 92.75%, yield 31.2%) was obtained as a white solid.

[0119] MS (ESI) M / Z: 511.2 [M+H] + .

[0120] 1 H NMR: ET88364-18-P1A;

[0121] 1 H NMR(DMSO-d6,400MHz)δ12.40(s,1H),8.60(s,1H),7.83(s,1H),5.61-5.50(m,3H) ,4.65-4.55(m,1H),4.47-4.36(m,2H),2.00(d,J=12.8Hz,9H),1.20-0.84(m,9H).

[0122] Example 10 Step 10: Synthesis of Compound 11

[0123] Under nitrogen protection, potassium carbonate (67.6 mg, 489 μmol), tris(dibenzylideneacetone)dipalladium (17.9 mg, 19.5 μmol) and 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene (11.3 mg, 19.5 μmol) were added to a solution of tert-butyl (2R,3R,4S,5S)-3,4-diacetoxy-2-(acetoxymethyl)-5-(4-chloro-5H-pyrrolo[3,2-d]pyrimidin-7-yl)pyrrolidine-1-carboxylate (100 mg, 195 μmol) and benzophenone imine (53.2 mg, 293 μmol) in anhydrous dioxane (2 mL) and the reaction mixture was stirred at 100°C for 12 h. After the reaction was cooled, the reaction mixture was diluted with pure water (10 mL) and extracted with dichloromethane (10 mL x 3). The combined organic layers were washed with brine (15 mL), dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure to obtain a residue. The crude product was purified by flash silica gel chromatography ( 4 The residue was purified by silica gel column, 0-100% ethyl acetate / petroleum ether gradient elution, 35 mL / min) to obtain the compound (2R,3R,4S,5S)-3,4-diacetoxy-2-(acetoxymethyl)-5-[4-(benzoylamino)-5H-pyrrolo[3,2-d]pyrimidin-7-yl]pyrrolidine-1-carboxylic acid tert-butyl (60 mg, purity 90%, yield 46.7%) as a yellow oil.

[0124] MS (ESI) M / Z: 656.3 [M+H] + .

[0125] 1 H NMR: ET88364-20-P1A;

[0126] 1 H NMR(DMSO-d6,400MHz)δ11.70(d,J=3.6Hz,1H),8.38(s,1H),7.82-7.70(m,2H),7.68-7.59(m,3H),7.57-7.50(m,2H),7.48-7.41(m,2H),6.90- 6.83(m,1H),5.76(s,1H),5.52-5.45(m,2H),5.41(d,J=5.2Hz,1H),4.5 5-4.47(m,1H),4.44-4.28(m,3H),2.01-1.93(m,9H),0.97-0.75(m,9H).

[0127] Example 11 Step 11: Synthesis of Compound 12

[0128] Dissolve (2R,3R,4S,5S)-3,4-diacetoxy-2-(acetoxymethyl)-5-[4-(benzoylamino)-5H-pyrrole[3,2-d]pyrimidin-7-yl]pyrrolidine-1-carboxylic acid tert-butyl (40 mg) in methanol solution (1 mL), add potassium carbonate (33.7 mg, 244 μmol), and stir the reaction solution at 25°C for 30 minutes. Filter the reaction mixture, pull dry the crude product, and analyze it by high performance liquid chromatography (acidic conditions, column: Phenomenex Luna C18

[0129] 75*30mm*3um; mobile phase: [H2O(0.1% TFA)-ACN]; gradient: 20%-50% B over 8.0min) to separate and purify the compound (2S,3S,4R,5R)-2-[4-(benzylamino)-5H-pyrrole[3,2-d]

[0130] Pyrimidin-7-yl]-3,4-dihydroxy-5-(hydroxymethyl)pyrrolidine-1-carboxylic acid tert-butyl (25 mg, 47.2 μmol, purity 95%, yield 77.4%) was obtained as a white solid.

[0131] MS (ESI) M / Z: 530.3 [M+H] + .

[0132] 1 H NMR(DMSO-d6,400MHz)δ9.87(d,J=2.5Hz,1H),9.10(s,1H),8.14(d,J=2.5Hz,1H),7.60 -7.47(m,4H),7.55-7.41(m,6H),5.13(d,J=6.3Hz,1H),4.86(d,J=5.1Hz,1H),4.79(d,J =5.3Hz,1H),4.60(dt,J=6.2,5.4,5.4Hz,1H),4.44(t,J=7.0,7.0Hz,1H),4.22(dt,J=6 .7, 4.9, 4.9Hz, 1H), 4.11-3.96 (m, 2H), 3.49 (ddd, J = 11.0, 7.1, 4.9Hz, 1H), 1.52 (s, 9H).

[0133] Example 12 Step 12: Synthesis of Galisvir

[0134] Dissolve (2S,3S,4R,5R)-2-[4-(benzylamino)-5H-pyrrolo[3,2-d]pyrimidin-7-yl]-3,4-dihydroxy-5-(hydroxymethyl)pyrrolidine-1-carboxylic acid tert-butyl (24 mg) in water (1.25 mL), add concentrated hydrochloric acid (12M, 1.49 mL), and stir the reaction solution at 25°C for 1 h. The reaction mixture was diluted with pure water (5 mL), back-extracted with ethyl acetate (5 mL x 3), and the aqueous phase was directly concentrated under reduced pressure to obtain the target compound (2S,3S,4R,5R)-2-(4-amino-5H-pyrrolo[3,2-d]pyrimidin-7-yl)-5-(hydroxymethyl)pyrrolidine-3,4-diol hydrochloride (7 mg, purity 95%, yield 51.2%) as a yellow solid white solid, that is, galisvir.

[0135] MS (ESI) M / Z: 266.2 [M+H] + .

[0136] 1 H NMR: ET88364-24-P1B1;

[0137] 1 H NMR (D2O, 400MHz) δ8.31 (s, 1H), 7.91 (s, 1H), 4.90 (d, J = 8.8Hz, 1H), 4.70 (dd, J = 4 .8,8.8Hz,1H),4.37(dd,J=3.6,4.8Hz,1H),3.90-3.87(m,1H),3.83-3.79(m,1H).

[0138] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing galisvir, characterized in that: The structural formula of galisvir is as follows: The preparation method comprises the following steps: 1) Compound 10 reacts with benzophenone imine under alkaline conditions to obtain compound 11; II) Compound 11 is hydrolyzed to obtain compound 12; III) Compound 12 reacts under acidic conditions to obtain galisvir; In step I), the solvent is dioxane, the catalyst is a mixture of tris(dibenzylideneacetone)dipalladium and 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene in a molar ratio of 1:0.8-1.5, and the alkalinity is provided by potassium carbonate.

2. The preparation method according to claim 1, characterized in that In step I), the molar ratio of compound 10 to benzophenone imine is 1:1-2; the reaction conditions are 90-110° C. for 8-15 h.

3. The preparation method according to claim 1, characterized in that: In step I), the mass volume ratio of compound 10 to solvent is 1 g:(10-30) mL, the molar ratio of compound 10 to catalyst is 2-10:1, and the molar ratio of compound 10 to potassium carbonate is 1:2-3.

4. The preparation method according to claim 3, characterized in that: In step I), the catalyst is tris(dibenzylideneacetone)dipalladium and 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene in a molar ratio of 1:

1.

5. The preparation method according to claim 1, characterized in that: In step II), the solvent is alcohol, the catalyst is potassium carbonate; the mass volume ratio of compound 11 to the solvent is 1 g:(15-40) mL, and the mass ratio of compound 11 to the catalyst is 1:0.5-2; the reaction conditions are reaction at room temperature for 10-60 min.

6. The preparation method according to claim 5, characterized in that: In step II), the alcohol is selected from at least one of methanol, ethanol, propanol and n-butanol.

7. The preparation method according to claim 1, characterized in that: In step III), the solvent is water, and the acidity is provided by concentrated acid; the mass volume ratio of compound 12 to water is 1 g: (30-80) mL, and the mass volume ratio of compound 12 to concentrated acid is 1 g: (40-80) mL; the reaction conditions are reaction at room temperature for 30-90 min.

8. The preparation method according to claim 7, characterized in that: In step III), the concentrated acid is selected from concentrated hydrochloric acid, concentrated sulfuric acid and concentrated nitric acid with a molar concentration of 8-15M.

9. The preparation method according to claim 1, characterized in that: The preparation of compound 10 comprises the following steps: 1) Compound 7 is hydrolyzed under acidic conditions to obtain compound 8; 2) Compound 8 reacts with Boc anhydride and acetic anhydride in sequence to obtain compound 9; 3) Compound 9 reacts with a chlorination agent to obtain the galisvir intermediate compound 10; 10. The preparation method according to claim 9, characterized in that: The preparation of compound 7 comprises the following steps:

11. The preparation method according to claim 10, characterized in that: In step S1, anhydrous methyl tert-butyl ether and anisole in a volume ratio of 2-4:1 are used as solvent, and a n-butyl lithium tetrahydrofuran solution with a molar concentration of 1-4M is used as catalyst; the mass volume ratio of compound 3 to the solvent is 1g:(15-30)mL, and the mass volume ratio of compound 3 to the catalyst is 1g:(1.5-2)mL; the molar ratio of compound 3 to compound R02 is 1:1-2; and the reaction conditions are -78°C for 1-3h.

12. The preparation method according to claim 10, characterized in that: The preparation of compound 3 comprises the following steps:

13. A method for preparing a calisvir intermediate, characterized in that: The galisvir intermediate is shown as compound 11, and its preparation method includes: The reaction solvent is dioxane, the catalyst is a mixture of tris(dibenzylideneacetone)dipalladium and 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene in a molar ratio of 1:0.8-1.5, and the alkalinity is provided by potassium carbonate.

14. A method for preparing a calisvir intermediate, characterized in that: The galisvir intermediate is shown as compound 12, and its preparation method comprises: Wherein, in step I), the reaction solvent is dioxane, the catalyst is a mixture of tris(dibenzylideneacetone)dipalladium and 4,5-bis(diphenylphosphine)-9,9-dimethylxanthene in a molar ratio of 1:0.8-1.5, and the alkalinity is provided by potassium carbonate.

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