Preparation method of GalNac intermediate

Abstract

The invention provides a preparation method of a Galnac intermediate. The method is high in process operability, the process safety is greatly improved, and the method is suitable for industrial application.

Description

Technical Field

[0001] This invention belongs to the field of drug synthesis, specifically relating to the preparation method of GalNac intermediates and their applications. Background Technology

[0002] Targeted delivery of oligonucleotides to hepatocytes using N-acetylgalactosamine (GalNAc) conjugates that bind to the asialic acid glycoprotein receptor (ASGPR) has become a breakthrough approach in the field of therapeutic oligonucleotides. ASGPR is an ideal target for delivering therapeutic oligonucleotides to the liver because it combines tissue specificity, high expression levels (500,000 copies / cell), and rapid internalization and turnover (15 minutes). GalNAc conjugations have yielded a number of FDA-approved siRNA drugs and numerous clinical candidates targeting multiple targets in hepatocytes. In addition to oligonucleotides, GalNAc is also conjugated with small molecules, peptides, proteins, and LNPs for targeting hepatocytes. Therefore, providing a process suitable for the industrial production of GalNAc is of great significance. Summary of the Invention

[0003] During a long period of research and development, the inventors developed a novel method for preparing (IX) compounds. The reaction conditions of this invention are mild, the process is mature, the quality is stable, and it is very suitable for industrial applications.

[0004] This invention provides a method for preparing a compound of formula (IX), characterized in that the compound of formula (IX) is obtained by removing a protecting group from a compound of formula (XIII), wherein the reaction catalyst is one or a combination of two or more of the following: nickel dimethyl ether ethylene glycol bromide, nickel bromide, nickel iodide, nickel dibromobis(pyridine)dibromo, nickel (2,2'-bipyridine)diiodide, nickel 2,2'-bipyridine chloride, nickel dibromo(1,10-phenanthroline-KN1,KN10)dibromo, and nickel (2,2'-bipyridine)dibromo (II), and the reaction is carried out in the presence of a Grignard reagent;

[0005]

[0006] R1 is a solid support or phosphoramide or C1-6 alkyl group connected by a linking group, either H or a hydroxyl protecting group;

[0007] R2 is a solid support or phosphoramide or C1-6 alkyl group connected by a linking group, either H or a hydroxyl protecting group;

[0008] Each R3 and R4 is independently selected from H or oxo, wherein when R3 or R4 is selected from oxo, the bond between R3 or R4 and the carbon it is attached to is a double bond;

[0009] R is an amino protecting group, preferably a sulfonyl amino protecting group;

[0010] s and t are each independently selected from 0, 1, 2, 3, 4 and 5;

[0011] m can be independently selected from 0, 1, 2, 3, 4, and 5;

[0012] n can be independently selected from 1, 2, 3, 4, and 5;

[0013] m1 and n1 are each independently selected from 0, 1, 2, 3 and 4.

[0014] In a preferred embodiment, according to the preparation method of the present invention, each of the hydroxyl protecting groups is independently selected from acetyl, tert-butyldimethylsilyl (TBMDS), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), 9-phenylxanthine-9-yl (Pixyl), 9-(p-methoxyphenyl)xanthine-9-yl (Mox), substituted or unsubstituted triphenylmethyl, and the substituents are 1, 2, 3, 4 or 5 independently selected from C 1-6 Alkyl, C 1-6 Alkoxy, C 1-6 Haloalkyl, C 1-6 The hydroxyl protecting group is a group consisting of a haloalkoxy group; the hydroxyl protecting group is preferably selected from monomethoxytriphenylmethyl, dimethoxytriphenylmethyl, and trimethoxytriphenylmethyl; more preferably, the hydroxyl protecting group is selected from 4-methoxytriphenylmethyl (MMTr), tricresyl, and...

[0015] In a preferred embodiment, according to the preparation method of the present invention, the sulfonyl amino protecting group is selected from benzenesulfonyl, p-methylbenzenesulfonyl, p-nitrobenzenesulfonyl, o-nitrobenzenesulfonyl or 2,4-dinitrobenzenesulfonyl.

[0016] In a preferred embodiment, the present invention provides a method for preparing a compound of formula (IX), characterized in that the compound of formula (IX) is obtained by removing a protecting group from a compound of formula (XIII).

[0017]

[0018] The reaction catalyst is one or a combination of two or more of the following: ethylene glycol dimethyl ether nickel bromide, nickel bromide, nickel iodide, dibromobis(pyridine) nickel, (2,2'-bipyridine) nickel diiodide, 2,2'-bipyridine nickel chloride, dibromo(1,10-phenanthroline-KN1,KN10) nickel, and (2,2'-bipyridine) dibromo nickel (II), and the reaction is carried out in the presence of a Grignard reagent.

[0019] On the other hand, the present invention provides the application of a nickel-containing catalyst in the removal of sulfonyl protecting groups from amino compounds protected by sulfonyl protecting groups, characterized in that the nickel-containing catalyst is selected from one or more combinations of nickel dimethyl ether bromide, nickel bromide, nickel iodide, dibromobis(pyridine)nickel, (2,2'-bipyridine)diiodide, 2,2'-bipyridine nickel chloride, dibromo(1,10-phenanthroline-KN1,KN10)nickel, and (2,2'-bipyridine)dibromonickel(II). Preferably, the reaction is carried out in the presence of a Grignard reagent, and more preferably, an ether solvent is used as the reaction solvent.

[0020] As a preferred embodiment, the Grignard reagent of the present invention is R-Mg-X, where R is an optionally substituted C. 1-12 Alkyl or optionally substituted C 6-12 Aryl group, preferably R is C 1-6 The alkyl group, where X is a halogen, preferably F, Cl, Br, I; more preferably one or a combination of two or more of iPrMgCl, isopropyl magnesium bromide, isopropyl magnesium iodide, methyl magnesium chloride, methyl magnesium bromide, 1-hexyl magnesium chloride, 1,1-dimethylpropyl magnesium chloride, propyl magnesium chloride, and propyl magnesium bromide.

[0021] As a preferred embodiment, the solvent for the reaction described in this invention is an aprotic solvent, preferably an ether, or preferably one or a mixture of two of Et2O, MTBE, THF, 2-methyltetrahydrofuran, DMA, isopropyl ether, benzene, toluene, DMSO, DMF, NMP, and 1,4-dioxane, with THF being the most preferred.

[0022] As a preferred embodiment, the reaction temperature of the reaction described in this invention is 0-100℃, preferably 15-60℃, and more preferably 20-30℃.

[0023] As a preferred embodiment, the amount of one or more of the following compounds—ethylene glycol dimethyl ether nickel bromide, nickel bromide, nickel iodide, dibromobis(pyridine) nickel, (2,2'-bipyridine) nickel diiodide, 2,2'-bipyridine nickel chloride, dibromo(1,10-phenanthroline-KN1,KN10) nickel, and (2,2'-bipyridine) dibromo nickel (II)—is 0.01-2.5 eq, preferably 0.01-1 eq, more preferably 0.05-0.1 eq; and the amount of Grignard reagent is 1-20 eq, preferably 5-15 eq, more preferably 10 eq.

[0024] As a preferred embodiment, the reaction time of the reaction described in this invention is preferably 1-72 hours, and more preferably 18-50 hours.

[0025] On the other hand, the present invention provides the application of the aforementioned method for preparing compound (IX) by removing protecting groups from compound (XIII) in the preparation of compound (X), characterized in that the structure of compound (X) is as follows:

[0026] The preparation method described in this patent uses readily available raw materials. Compared to existing technologies, this method is milder, safer, and more suitable for industrial production. Furthermore, in a further optimized version, an even higher reaction yield can be obtained. Detailed Implementation

[0027] Detailed explanation: Unless otherwise stated, the terms used in the specification and claims shall have the following meanings.

[0028] "Alkyl" refers to both straight-chain alkyl and branched-chain alkyl groups. Alkyl refers to saturated aliphatic hydrocarbon groups, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, etc.

[0029] The “alkoxy” non-limiting examples include methoxy, ethoxy, propoxy, butoxy, etc.

[0030] "Cycloalkyl" refers to a saturated or partially unsaturated monocyclic or polycyclic cyclic hydrocarbon substituent, "C 3-8 "Cycloalkyl" refers to a cycloalkyl group that includes 3 to 8 carbon atoms.

[0031] "Ether solvents" refer to hydrocarbon compounds containing ether bonds in their molecules. They can be chain ethers or cyclic ethers, such as methyl ether, diethyl ether, methyl tert-butyl ether, isopropanol, tetrahydrofuran, dioxane, and anisole.

[0032] "Substituted" means that one or more hydrogen atoms in the group, preferably up to five, more preferably one to three hydrogen atoms, are independently substituted by the corresponding number of substituents. It goes without saying that the substituents exist in their only possible chemical positions. Those skilled in the art can determine whether substitution is possible or impossible without much effort through experimentation or theory. For example, a combination of an amino or hydroxyl group with free hydrogen and a carbon atom with an unsaturated bond (such as an alkene) may be unstable.

[0033] When substitution occurs, the substituent can be substituted at any available connection point; preferably, the substituent is one or more independently selected C. 1-6 Alkyl, halogen, C 1-6 Alkoxy, C 1-6 alkenyl, C 1-6 alkynyl group, C 1-6 alkylsulfonyl, C 1-6 Alkylamino, thiol, hydroxyl, nitro, cyano, amino, C 1-8 cycloalkyl, C 1-8Heterocyclic alkyl, C 6-12 Aryl, C 1-6 heteroaryl, C 1-8 Cycloalkoxy, C 1-6 Heterocyclic oxides, C 1-8 cycloalkylthio, C 1-6 Substituents in the group consisting of heterocyclic alkyl thio groups and oxo groups.

[0034] The hydroxyl protecting group can be any type of hydroxyl protecting group, as long as it can protect the hydroxyl group. Examples include silyl protecting groups (e.g., tert-butyldimethylsilyl ether (TBMDS), tert-butyldiphenylsilyl ether (TBDPS), triisopropylsilyl ether (TIPS)) or monomethoxytriphenylmethyl (MMTr) or 4,4'-dimethoxytriphenylmethyl (DMTr) or tricrylyl or any other suitable protecting group, such as those mentioned in Wuts, Peter GM, and Theodora W. Greene, Greene's protective groups inorganic synthesis. John Wiley & Sons, 2006. In some alternative embodiments, the hydroxyl protecting group is stable under basic conditions but can be removed under acidic conditions.

[0035] The amino protecting group can be any type of amino protecting group, as long as it can protect the amino group, and the specific type is not limited. It is preferably a sulfonyl amino protecting group; more preferably it is benzenesulfonyl, p-methylbenzenesulfonyl, p-nitrobenzenesulfonyl, o-nitrobenzenesulfonyl or 2,4-dinitrobenzenesulfonyl.

[0036] The present invention will be further described in detail and completely below with reference to the embodiments, but this is by no means a limitation of the present invention, nor is the present invention limited to the contents of the embodiments.

[0037] The starting materials used in the embodiments of the present invention are known and commercially available, or can be synthesized using or in accordance with methods known in the art.

[0038] Example 1: Ts removal process

[0039]

[0040] At room temperature (15–30°C), 176.38 g (0.29 mol) of (6-(bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-toluenesulfonyl-2-azaspiro[3.3]heptane-6-yl)methanol, 4.41 g (0.01 mol) of ethylene glycol dimethyl ether nickel bromide, and 176 mL of THF were weighed into a reactor, stirred and dissolved, and purged with nitrogen. The system was then cooled to 0–5°C, and 2 M isopropyl magnesium chloride was added. THF solution (2.87 mol), stirred at 25-30℃ for 40-48 h; after the reaction was complete, the system was cooled to 0-5℃, 2.5 L of water was added, and the mixture was stirred vigorously for 5-10 min; 2.5 L of EA was added, and the mixture was stirred vigorously for 3-5 min. After standing, there was no obvious layering. 1 L of 8% ammonium chloride aqueous solution was added, and after standing, the system quickly separated into layers; the filtrate was separated, the aqueous phase was extracted with EA, the organic phases were combined, and the organic phases were washed with saturated ammonium chloride aqueous solution and saturated brine, respectively, and the organic phases were concentrated. Column chromatography was performed, eluted, and dried to obtain (6-(bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-azaspiro[3.3]heptane-6-yl)methanol (70.55 g, 53.4%).

[0041] 1H NMR(400MH,DMSO)δ7.41-7.16(m,9H),6.94-6.85(m,4H),4.55(s,1H),3.74(s,5H),3.73( d,J=8.9Hz,1H),3.38(d,J=7.8Hz,4H),2.95-2.88(m,1H),2.89(s,2H),1.94-1.73(m,4H).

[0042] ESI-MS(M+H)+: 460.3 m / z.

[0043] Example 2: Condensation process

[0044]

[0045] Add (6-(bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-azaspiro[3.3]heptane-6-yl)methanol (70.55 g, 0.15 mol), DCM 700 mL, HOBT (41.49 g, 0.31 mol), EDCI (88.07 g, 0.46 mol), and DIEA (79.36 g, 0.61 mol) to the reactor and stir at 15–30 °C for 1.5–2 h. This system is labeled as solution ①. Weigh 6-(5-(((2R,3R,4R,5R,6R)-3-acetamido-4,5-diacetoxy-6-(acetoxymethyl)tetrahydro-2H-pyran-2-yl)oxy)pentamido)hexanoic acid (103.27 g, 0.18 mol), DCM Dissolve the mixture in 306 mL of water with stirring. This system is labeled as solution ②. Add solution 1 to solution ② and stir for 2–2.5 h until the reaction is complete. Wash the reaction solution once with water and once with saturated sodium chloride. After drying with sodium sulfate, evaporate to dryness to obtain the target product (2R, 3R, 4R, 5R, 6R)-5-acetamido-2-(acetoxymethyl)-6-((5-((6-(6-(bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-6-(hydroxymethyl)-2-azaspiro[3.3]hept-2-yl)-6-oxohexyl)amino)-5-oxopentyl)oxy)tetrahydro-2H-pyran-3,4-dimethyldiacetate (98.07 g, 75%).

[0046] 1H NMR (400MH, DMSO) δ7.82 (d, J = 9.2Hz, 1H), 7.74-7.66 (m, 1H), 7.44-7.35 (m, 2H), 7.28-7.19 (m, 5H), 6 .95-6.86(m,4H),5.22(d,J=3.4Hz,1H),5.02-4.93(m,1H),4.67-4.60(m,1H),4.49(d,J=8.5Hz,1H) ,4.10-3.98(m,4H),3.98(s,1H),3.74(s,6H),3.72-3.64(m,3H),3.52(s,1H),3.46-3.36(m,3H),3. 06-2.95(m,2H),2.92(s,2H),2.10(s,3H),2.08-1.74(m,17H),1.57-1.29(m,8H),1.24-1.14(m,2H)

[0047] Example 3: Phosphite treatment process

[0048]

[0049] MG-008 (7.2 g, 6.9 mmol) and anhydrous DCM (72.0 mL) were added to a reaction flask and dissolved. Then, DCI (0.74 g, 6.28 mmol) and CEP[N(iPr)2]2 (2.73 g, 9.07 mmol) were added at room temperature. The mixture was stirred at room temperature for 1 h until the reaction was complete. The reaction solution was quenched with water, the organic phase was washed with saturated sodium chloride, dried over anhydrous sodium sulfate, filtered, concentrated, and purified by HPLC. The product solutions were combined, extracted with DCM, the organic phase was washed with saturated sodium chloride, dried over anhydrous sodium sulfate, and concentrated to dryness to give a white solid compound 2-11 (6.4 g, 97% purity, 75% yield).

[0050] 1H-NMR (400MHz, DMSO-d6): δ=7.82-7.68(m,2H),7.26-7.23(m,6H),6.89-6.86(m,6H) ,5.22-5.21(d,J=4.0Hz,1H),4.98-4.96(m,1H),4.49-4.48(d,J=4.0Hz,1H),4.05-3. 96(m,4H),3.90-3.83(m,1H),3.73-3.37(m,18H),3.02-2.94(m,4H),2.74-2.72(m,2H ),2.10-1.77(m,20H),1.51-1.08(m,22H);31PNMR(161MHz,DMSO-d6)δ146.82,146.70.

[0051] Comparative Example 1:

[0052] Add (1.2 g, 1.96 mmol) of (6-(bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-toluenesulfonyl-2-azaspiro[3.3]heptane-6-yl)methanol, Mg (600.00 mg, 24.68 mmol), and MeOH (20 mL) to a round-bottom flask. Stir at room temperature. After half an hour, the temperature is raised sharply and reflux is obvious. Stirring continues, and the reaction is completed after 5 hours. Add water, and magnesium hydroxide precipitates. Add EA, extract and evaporate to dryness, then perform column chromatography. For column hydration, use PE with 1‰ triethylamine. Dissolve the sample in DCM and load it wet. The mobile phase PE:EA = 3:1 (add 1-3‰ triethylamine) quickly elutes the small polar impurities at the top. Increase the mobile phase to PE:EA = 1:1 (add 1-3‰ triethylamine) to elute the raw material. Then change the mobile phase to DCM:methanol = 3:1 to 1:1 (add 3-5% triethylamine). The product is (6-(bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-azaspiro[3.3]heptane-6-yl)methanol (240 mg, 26.7%).

[0053] Example 4:

[0054] Screening of Ts removal process conditions

[0055]

[0056] The reaction can be performed using a variety of reaction solvents:

[0057] Table 1

[0058]

[0059] Among them, THF solvent is a homogeneous system, which is easy to scale up.

[0060] The equivalent of iPrMgCl and Ni catalysts can be varied:

[0061] Table 2

[0062]

Claims

1. A method for preparing a compound of formula (IX), characterized in that, The compound of formula (IX) is obtained by removing the protecting group from the compound of formula (XIII), wherein the reaction catalyst is one or a combination of two or more of the following: nickel dimethyl ether ethylene glycol bromide, nickel bromide, nickel iodide, nickel dibromobis(pyridine)dibromo, nickel (2,2'-bipyridine)diiodide, nickel 2,2'-bipyridine chloride, nickel dibromo(1,10-phenanthroline-KN1,KN10)dibromo, and nickel (2,2'-bipyridine)dibromo (II), and the reaction is carried out in the presence of a Grignard reagent; R1 is selected from H or hydroxyl protecting groups or optionally from a solid support or phosphoramide linked by a linking group. 1-6 alkyl; R2 is selected from H or hydroxyl protecting groups or optionally from solid supports or phosphoramides linked by linking groups. 1-6 Alkyl; each R3, R4 is independently selected from H or oxo, wherein when R3, R4 is selected from oxo, the bond between R3 or R4 and the carbon to which it is attached is a double bond; R is an amino protecting group, preferably a sulfonyl amino protecting group; s and t are each independently selected from 0, 1, 2, 3, 4 and 5; m can be independently selected from 0, 1, 2, 3, 4, and 5; n can be independently selected from 1, 2, 3, 4, and 5; m1 and n1 are each independently selected from 0, 1, 2, 3 and 4.

2. The preparation method according to claim 1, wherein each of the hydroxyl protecting groups is independently selected from acetyl, tert-butyldimethylsilyl (TBMDS), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), 9-phenylxanthine-9-yl (Pixyl), 9-(p-methoxyphenyl)xanthine-9-yl (Mox), substituted or unsubstituted triphenylmethyl, and the substituents are 1, 2, 3, 4 or 5 independently selected from C 1-6 Alkyl, C 1-6 Alkoxy, C 1-6 Haloalkyl, C 1-6 The hydroxyl protecting group is a group consisting of a haloalkoxy group; the hydroxyl protecting group is preferably selected from monomethoxytriphenylmethyl, dimethoxytriphenylmethyl, and trimethoxytriphenylmethyl; more preferably, the hydroxyl protecting group is selected from 4-methoxytriphenylmethyl (MMTr), tricresyl, and...

3. The preparation method according to claim 1, wherein the sulfonyl amino protecting group is selected from benzenesulfonyl, p-methylbenzenesulfonyl, p-nitrobenzenesulfonyl, o-nitrobenzenesulfonyl or 2,4-dinitrobenzenesulfonyl.

4. The preparation method according to any one of claims 1-3, characterized in that, Compound (IX) is obtained by removing the protecting group from compound (XIII). The reaction catalyst is one or a combination of two or more of the following: ethylene glycol dimethyl ether nickel bromide, nickel bromide, nickel iodide, dibromobis(pyridine) nickel, (2,2'-bipyridine) nickel diiodide, 2,2'-bipyridine nickel chloride, dibromo(1,10-phenanthroline-KN1,KN10) nickel, and (2,2'-bipyridine) dibromo nickel (II), and the reaction is carried out in the presence of a Grignard reagent.

5. The preparation method according to any one of claims 1-4, wherein the Grignard reagent is R-Mg-X, where R is an optionally substituted C1-12 alkyl group or an optionally substituted C 6-12 Aryl group, preferably R is C 1-6 The alkyl group, where X is a halogen, preferably F, Cl, Br, I; more preferably one or a combination of two or more of iPrMgCl, isopropyl magnesium bromide, isopropyl magnesium iodide, methyl magnesium chloride, methyl magnesium bromide, 1-hexyl magnesium chloride, 1,1-dimethylpropyl magnesium chloride, propyl magnesium chloride, and propyl magnesium bromide.

6. The preparation method according to any one of claims 1-5, wherein the solvent of the reaction is an aprotic solvent, preferably an ether, or preferably one or a mixture of two of Et2O, MTBE, THF, 2-methyltetrahydrofuran, DMA, isopropyl ether, benzene, toluene, DMSO, DMF, NMP, and 1,4-dioxane, with THF being the most preferred.

7. The preparation method according to any one of claims 1-6, wherein the reaction temperature is 0-100℃, preferably 15-60℃, more preferably 20-30℃.

8. The preparation method according to any one of claims 1-7, wherein the amount of one or more combinations of ethylene glycol dimethyl ether nickel bromide, nickel bromide, nickel iodide, dibromobis(pyridine) nickel, (2,2'-bipyridine) nickel diiodide, 2,2'-bipyridine nickel chloride, dibromo(1,10-phenanthroline-KN1,KN10) nickel, and (2,2'-bipyridine) dibromo nickel (II) is 0.01-2.5 eq, preferably 0.01-1 eq, more preferably 0.05-0.1 eq; and the amount of the Grignard reagent is 1-20 eq, preferably 5-15 eq, more preferably 10 eq.

9. The application of the preparation method according to any one of claims 1-8 in the preparation of compound (X), characterized in that, The structure of the compound of formula (X) is as follows:

10. The application of nickel-containing catalysts in the removal of sulfonyl protecting groups from amino compounds protected by sulfonyl protecting groups, characterized in that, The nickel-containing catalyst is selected from one or more of nickel bromide, nickel bromide, nickel iodide, nickel dibromobis(pyridine)dibromo, nickel (2,2'-bipyridine)diiodide, nickel 2,2'-bipyridine chloride, nickel dibromo(1,10-phenanthroline-KN1,KN10)dibromo, and nickel (2,2'-bipyridine)dibromo(II); preferably, the reaction is carried out in the presence of a Grignard reagent, and more preferably, an ether solvent is used as the reaction solvent.

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