Process for preparation of nanomodnosen

Abstract

The present disclosure relates to a process for the preparation of nanomodnoson of the following formula (I), which process is suitable for large-scale production, for example, in accordance with good production specifications (GMP). The process disclosed by the invention comprises the steps of protection, oxidation, chlorination, amination, reaction, final deprotection and the like.

Description

Technical Field

[0001] This topic relates to a process for preparing a highly specific and selective A3 adenosine receptor (A3AR) agonist (called namodenoson).

[0002] References

[0003] The following references are considered to be related to the general background of this disclosure:

[0004] Cohen S., et al., J. Cell Physiol. 2011; 226: 2438-2447

[0005] ·Stemmer SM, et al., Oncologist. 2013; 18:25-26

[0006] US 6,790,839

[0007] US 7,141,553

[0008] US 7,589,075

[0009] US 8,987,228

[0010] ·WO 2007 / 063538

[0011] ·WO 2009 / 050707

[0012] ·WO 2013 / 111132

[0013] ·WO 2017 / 090036 Background Technology

[0014] Namodinosine, 2-chloro-N6-(3-iodobenzyl)-adenosine-5′-N-methyluramide, also known in the scientific literature as Cl-IB-MECA, is a highly selective, orally bioavailable A3AR agonist. Namodinosin has been found to be effective in treating cancer (US 6,790,839 and WO 2013 / 111132), inflammatory diseases (US 7,141,553, US 8,987,228, WO2007 / 063538), inhibiting viral replication (US 7,589,075), inhibiting hepatocyte proliferation (WO 2009 / 050707), reducing ectopic fat accumulation (WO 2017 / 090036), and inducing apoptosis in HCC (hepatocellular carcinoma) in syngeneic orthotopic and xenograft experimental animal models (Cohen S., et al., J. Cell Physiol. 2011; 226:2438-2447).

[0015] In an open-label phase I / II trial, researchers evaluated the safety and efficacy of namodinosin in patients with advanced unresectable HCC, 67% of whom had previously failed sorafenib treatment. The median overall survival (OS) for the entire study population was 7.8 months, and for Child-Pugh B patients (28%), it was 8.1 months. Namodinosin was safe and well-tolerated, and baseline A3AR expression levels were directly correlated with tumor response to namodinosin (Stemmer SM, et al., Oncologist. 2013; 18:25-26). Summary of the Invention

[0016] The technical problem to be solved by this disclosure is to provide a process for preparing namodinosine.

[0017] This disclosure relates to a process for preparing Namodnosen of the following formula (I).

[0018]

[0019] This process is suitable for large-scale production, such as production according to Good Manufacturing Practices (GMP). The process disclosed herein includes steps such as protection, oxidation, chlorination, amination, reaction, and final deprotection, which will be discussed further below. Detailed Implementation

[0020] Before elaborating on this topic in detail, it may be helpful to provide definitions for certain terms used herein. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art related to this topic.

[0021] Unless otherwise specified, the terms "a" or "an" as used herein include both the singular and the plural. Therefore, the terms "a" or "at least one," "an" or "at least one" are used interchangeably in this application.

[0022] To better understand the invention and without limiting its scope, unless otherwise stated, all figures representing quantities, percentages, or proportions, as well as other numerical values ​​used in the specification and claims, should in all cases be understood to be modified by the term "about". Therefore, unless otherwise stated, the numerical parameters listed in the following specification and claims are approximate values ​​and may vary depending on the desired characteristics. At a minimum, each numerical parameter should be interpreted according to the number of significant digits reported and by applying common rounding techniques. In this regard, the term "about" refers to a quantity that may deviate (i.e., be higher or lower) by at most 10%, 15%, 20%, 25%, or even 30% of the stated quantity. For example, "about 10" should be understood to be in the range of 9-11, 8.5-11.5, 8-12, 7.5-12.5, or even 7-13. Even if the given value is not limited by "about", it should be understood to be close to the stated value, i.e., close to the value that may deviate as indicated in this paragraph.

[0023] Preparation process of Namodinosin

[0024] This topic provides a process for preparing (I) Namodnosen.

[0025]

[0026] The process includes the following steps:

[0027] (a) Protection of the hydroxyl group of 2,6-dichloropurine nucleoside diol of formula (II)

[0028]

[0029] Compound of formula (III) was obtained;

[0030]

[0031] (b) In the presence of an oxidizing agent, the compound of formula (III) is oxidized to obtain the compound of formula (IV);

[0032]

[0033] (c) Chloride the compound of formula (IV) to obtain the compound of formula (V);

[0034]

[0035] (d) Amination of compound (V) yields compound (VI);

[0036]

[0037] (e) Reacting compound (VI) with compound (VII)

[0038]

[0039] Compound of formula (VIII) was obtained; and

[0040]

[0041] (f) Deprotection treatment of compound (VIII).

[0042] Compared to methods known in the prior art, the process of this invention has the advantage of simplifying the production process of Namodinosin while increasing product yield and purity. Furthermore, this process reduces impurities, especially those that may be harmful to health.

[0043] Namodinosine produced by the process disclosed herein can be used in pharmaceuticals and can be scaled up in accordance with Good Manufacturing Practices (GMP).

[0044] The term "protection" as used here refers to the use of chemical components to protect the reactive portion of a molecule. In chemical reactions, protection is used to prevent side reactions from occurring on the reactive portion of a molecule, while simultaneously allowing manipulation or reaction on another part of the molecule.

[0045] In one embodiment, the compound of formula (III) is prepared from the compound of formula (II) via a diol protecting the 2,6-dichloropurine nucleoside of formula (II). Protection of the diol can be achieved by reacting the compound of formula (II) with 2,2-dimethoxypropane, typically in an inert solvent (such as acetone) in the presence of a catalytic amount of an acid catalyst. In a specific embodiment, the acid catalyst may be p-toluenesulfonic acid, etc. Alternatively, hydroxyl protecting groups may be used, such as methoxymethyl, benzyloxymethyl, 2-methoxyethoxymethyl, 2-(trimethylsilyl)ethoxymethyl, tert-butyl, benzyl, triphenylmethyl, 2,2,2-trichloroethyl, trimethylsilyl, tert-butyldimethylsilyl, tert-butyldiphenylsilyl, acetate, propionate, and benzoate.

[0046] The protection process is carried out at a temperature of about 0-20°C for about 10-20 hours. In one specific embodiment, compound (II) is protected at a temperature of about 0-10°C for about 16 hours. Once the reaction is substantially complete, compound (III) can be isolated by conventional methods, such as filtration and drying of the filtered solid.

[0047] According to one embodiment, the oxidizing agent is a percarboxylic acid selected from sodium periodate or potassium periodate. In a specific embodiment, the oxidizing agent is sodium periodate.

[0048] According to one embodiment, oxidation can be carried out in the presence of a ruthenium-containing catalyst and a solvent. The catalyst used in this subject matter is metallic ruthenium, inorganic ruthenium salts, or organic ruthenium salts. Inorganic ruthenium salts may include, but are not limited to, ruthenium chloride, ruthenium bromide, ruthenium dioxide, ruthenium sulfide, and ruthenium carbonate. Organic ruthenium salts may include, but are not limited to, ruthenium formate, ruthenium acetate, ruthenium propionate, and ruthenium butyrate. In one specific embodiment, the ruthenium-containing catalyst is ruthenium chloride.

[0049] The catalyst content can be between 0.00001% and 1.0% by weight of the reaction mixture. In one embodiment, the amount of catalyst can be between about 0.01% and 0.1% (by weight).

[0050] Solvents suitable for the oxidation step include any inert solvent that is not easily oxidized. The oxidation reaction can be carried out using water and an organic solvent as a dual-solvent system. In one embodiment, the organic solvent is acetonitrile.

[0051] To accelerate the oxidation reaction, a phase transfer catalyst can be used simultaneously. The phase transfer catalyst used in the oxidation step may include, but is not limited to, tetrabutylammonium iodide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, triethylbenzylammonium chloride, triethylbenzylammonium bromide, and triethylbenzylammonium iodide. In one embodiment, the phase transfer catalyst is tetrabutylammonium iodide.

[0052] The oxidation reaction is carried out at a temperature of about 10-40°C for about 5-15 hours. In one specific embodiment, compound (III) is oxidized at a temperature of about 15-25°C for about 9 hours. Once the reaction is substantially complete, compound (IV) can be isolated by conventional methods.

[0053] The chlorination reaction is carried out in the presence of a chlorinating agent and at least one polar aprotic solvent. The chlorinating agent may be selected from the following group: thionyl chloride, phosphorus oxychloride, phosgene, thionyl chloride, phosphorus pentachloride, triphosgene, diphosgene, and oxalyl chloride. In one specific embodiment, the chlorinating agent is thionyl chloride.

[0054] The polar aprotic solvent may be selected from acetonitrile, methyl tert-butyl ether, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, dimethylformamide, dimethylacetamide, ethyl acetate, acetone, dimethyl sulfoxide, methyl isobutyl ketone, isopropyl acetate, 2-ethyltetrahydrofuran, 1,4-dioxane, CPME (cyclopentyl methyl ether), dimethoxyethane, diethylene glycol dimethyl ether, and diethoxymethane. In one specific embodiment, the polar aprotic solvent is acetonitrile.

[0055] The amination reaction can be carried out in the presence of an aminating agent selected from methylamine, tert-butylamine, benzylamine, p-methoxybenzylamine, 3,4-dimethoxybenzylamine, allylamine, methoxymethylamine, triphenylmethylamine, benzoylamine, dinitroaniline, and p-methoxyphenylamine. In one specific embodiment, the aminating agent is methylamine.

[0056] Amination reactions can be carried out in the presence of a base. Suitable bases include tertiary amines such as trimethylamine, triethylamine, diisopropylethylamine (DIPEA), pyridine, 4-dimethylaminopyridine (DMAP), and N-methylmorpholine.

[0057] According to one embodiment, the compound of formula (V) is not separated before reacting with the amination agent. According to another embodiment, chlorination and amination are carried out in one pot without separating the compound of formula (V).

[0058] According to one embodiment, the compound of formula (VIII) is not separated prior to the deprotection step. According to another embodiment, steps (d) and (e) are carried out in the same pot without separating the compound of formula (V).

[0059] The term "deprotection" as used herein refers to the removal of a chemical moiety used to protect a portion of a molecule by a deprotecting agent. For example, under nucleophilic substitution reaction conditions, this chemical moiety is readily substituted by a nucleophile. In one embodiment, the deprotecting agent can be an acid. The acid can be selected from, but is not limited to, hydrochloric acid, hydrobromic acid, sulfuric acid, phosphoric acid, acetic acid, and trifluoroacetic acid. In a specific embodiment, hydrochloric acid is used for the deprotection of compound (VIII). In another embodiment, compound (VIII) is deprotected with an acid (such as hydrochloric acid) in a suitable solvent (such as tetrahydrofuran) to provide the diol in compound (I).

[0060] In one embodiment, after deprotection of the compound of formula (VIII), the resulting crude compound of formula (I) is recrystallized. The crude compound of formula (I) can be recrystallized in a solution of dimethylformamide (DMF) and water.

[0061] According to one embodiment, the obtained compound of formula (I) has a purity of at least 80%, at least 85%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99%.

[0062] The progress of the reaction can be monitored using any suitable method, including chromatography such as high performance liquid chromatography (HPLC), thin layer chromatography (TLC), etc.

[0063] In another embodiment, the compound of formula (I) can be separated from the reaction mixture using any conventional technique well known in the art. Such separation techniques may include, but are not limited to, concentration, extraction, precipitation, cooling, filtration, crystallization, centrifugation, and combinations thereof, followed by drying.

[0064] In another embodiment, the compound of formula (I) may be purified using any conventional technique well known in the art. Such purification techniques may be selected from, but are not limited to, precipitation, crystallization, extraction, slurrying, washing in a suitable solvent, filtration through a packed bed column, dissolution in a suitable solvent, reprecipitation by adding a second solvent in which the compound is insoluble, and combinations thereof.

[0065] The following examples illustrate the application of this subject matter in certain embodiments. However, they should not be construed as limiting the scope of this subject matter. Other implementations will become apparent to those skilled in the art upon consideration of this specification and the examples. This specification (including the examples) is to be considered illustrative only and does not limit the scope and spirit of this subject matter.

[0066] Preparation of compound (III)

[0067] 218 kg of acetone, 69.2 kg of 2,6-dichloropurine nucleoside (compound (II)), and 3.5 kg of p-toluenesulfonic acid were added to a reactor. 67.5 kg of 2-dimethoxypropane was added to the reactor while maintaining an internal temperature of 0–10 °C. The reaction mixture was stirred for 6 hours. The reaction mixture was cooled to 0–10 °C, and then 692 kg of a 0.5% aqueous solution of NaHCO3 was added while maintaining an internal temperature of 0–10 °C. The mixture was stirred for 16 hours. The mixture was filtered, and the solid was washed with an acetone / water mixture. The solid was dried at 30–40 °C for 24 hours to give compound (III).

[0068] Preparation of compound (IV)

[0069] 66.9 kg of compound (III), 0.67 kg of ruthenium chloride, 0.70 kg of tetrabutylammonium iodide, and 790 kg of acetonitrile were added to a reactor. The mixture was stirred at 15–25 °C until all solids dissolved. 268 kg of water was added to the reactor, followed by the addition of 99.4 kg of sodium periodate in portions. The internal temperature was maintained between 15–25 °C. The reaction mixture was stirred for 9 hours. The mixture was filtered, and the solids were washed with acetonitrile. The combined filtrates were treated with 62 kg of a 20% Na₂SO₃ aqueous solution, filtered, and the solids were washed with acetonitrile. The combined filtrates were treated with 4 kg of a 20% Na₂SO₃ aqueous solution, filtered, and washed with acetonitrile.

[0070] The combined acetonitrile solution was processed by CUNO (Zeta Plus). TM Circulating filtration was performed using an activated carbon filter for 35 hours. The combined filtrate was concentrated under reduced pressure to 2-3V below 40°C, and then cooled to 15-25°C. 4 kg of a 7% Na₂SO₄ aqueous solution was slowly added to the concentrate while maintaining the internal temperature at 15-25°C. The mixture was then cooled to -3 to 8°C and stirred for 12 hours. The mixture was filtered, and the filter cake was washed with water. The solid was dried at 35-43°C.

[0071] Preparation of compound (V)

[0072] Add 432 kg of acetonitrile and 40.9 kg of compound (IV) to the reactor. Stir the mixture until all solids are dissolved. While maintaining an internal temperature of 20–30 °C, add 17.4 kg of thionyl chloride, then rinse with acetonitrile. Stir the reaction mixture for 4–12 hours. Add another 2.2 kg of thionyl chloride to complete the reaction.

[0073] Preparation of compound (VI)

[0074] Cool the mixture obtained in the previous step to -18 to -8°C. Add 3.6 kg of methylamine (8.1% by weight in THF) and 41.4 kg of N,N-diisopropylethylamine (DIPEA) while maintaining the internal temperature at -18 to -8°C. Stir the reaction mixture for 1-2 hours. Add another 2.0 kg of DIPEA and stir the reaction mixture for 1-2 hours. Add 124 kg of a 10% aqueous citric acid solution to the mixture while maintaining the internal temperature at -18 to -8°C. Concentrate the reaction mixture under reduced pressure below 40°C to 3-5V. Add 144 kg of acetonitrile to the reaction mixture and concentrate under reduced pressure below 40°C to 3-5V until all solvent is removed. Cool the concentrate to 20-30°C, then add 430 kg of 2-propyl acetate while maintaining the internal temperature at 20-30°C. Stir the mixture for 1-2 hours, then let it stand for 0.5-1 hour. The aqueous layer was extracted from the organic layer using 146 kg of 2-propylacetate. The combined organic layers were washed sequentially with 10% citric acid aqueous solution, 7% NaHCO3 solution, and 10% Na2SO4 solution. The resulting organic solution was filtered through a CUNO filter for at least 5 hours, followed by rinsing the CUNO filter with 2-propylacetate. The combined mixture was then concentrated under reduced pressure below 40°C to 3-5°C. 144 kg of 2-propylacetate was added to the concentrate. The mixture was concentrated again to 3-5°C. Another 147 kg of 2-propylacetate was added to the concentrate. The mixture was concentrated a third time to 3-5°C. Then, n-heptane was added to the concentrate while maintaining an internal temperature of 25±5°C. The mixture was cooled to 10±5°C and stirred for 15-20 hours. The mixture was filtered, and the solid was washed with n-heptane. The solid was dried at 35-45°C for 16-24 hours.

[0075] Preparation of compound (VIII)

[0076] Add 366 kg of dichloromethane, 25 kg of compound (VI), and 17.4 kg of 3-iodobenzylamine hydrochloride to a reactor. Stir the mixture at 20-30°C for 0.5-2 hours until the solids are completely dissolved. Add 25.2 kg of diisopropylethylamine, then wash the mixture with 12 kg of dichloromethane while maintaining the internal temperature at 20-30°C. Stir the reaction mixture at 30-40°C for 25-30 hours. Add 150 kg of a 10% citric acid aqueous solution to the mixture while maintaining the internal temperature at 10-20°C. Stir the mixture for 3-5 hours and separate the layers. Concentrate the organic layer to 3-5V under reduced pressure below 40°C. Add 128 L of THF to the organic layer. Concentrate the mixture again to 3-5V under reduced pressure below 40°C. Add 128 L of THF to the organic layer and concentrate a third time to 3-5V under reduced pressure below 40°C. Add 128 L of THF to the organic layer and concentrate to 3-5 V under reduced pressure for the fourth time at below 40°C. Add 277 L of THF to the organic layer. Filter the organic layer through a CUNO circulating filter for 5-10 hours. Combine the filtrates and concentrate to 12-13 V under reduced pressure at below 40°C. Add 75 L of THF to the concentrate.

[0077] Preparation of Namodinosin

[0078] Add 24.8 kg of 35% hydrochloric acid to the THF solution of the compound of formula (VIII) prepared in the previous step. Then wash the reaction mixture with 18 kg of THF while maintaining an internal temperature of 15-25°C. Heat the mixture to 25-35°C and stir for 20-30 hours. After cooling the mixture to -5-5°C, add 334 kg of 7% sodium bicarbonate aqueous solution to the mixture while maintaining an internal temperature of -5 to 5°C and a pH of 7. Concentrate the mixture under reduced pressure to 12-13°C. Add 137 kg of methanol and 82 kg of THF to the concentrate. Heat the mixture to 35-45°C and then cool to 15-25°C. Stir the mixture at 15-25°C for 12-16 hours and filter. Wash the solid with methanol / water. Adjust the solid to a slurry with water, filter, and wash again with water. The wet cake was remixed into a slurry in a mixture of water / MeOH / THF, filtered, washed with methanol / water, and then dried at 35-45°C to obtain crude Namodinosin.

[0079] Purification of Namodinosin (GMP purification)

[0080] Add 34.6 kg of crude nanomodinosine and 164 kg of dimethylformamide to a reactor. Stir the mixture at 20-30°C until all solids dissolve. While rinsing with dimethylformamide, filter the solution through a tubular filter into a second reactor. Heat the mixture to 45-55°C and stir for 0.5-1 hour. Add purified water to the mixture, then add 0.2 kg of nanomodinosine seed crystals. After stirring for 16-24 hours, add purified water over 0.5-1 hour. Stir the mixture again at 45-55°C for 16-24 hours. Over 20-24 hours, add 190 kg of purified water to the reactor. Stir the resulting mixture for another 5-10 hours. Filter the mixture and wash the solids with water. Dry the solids without stirring at 25-35°C for 4-8 hours, then at 45-55°C for 18-26 hours, and finally at 65-75°C for 48-72 hours. After sieving, 30.65 kg of the desired final product, namely namodinosin, was obtained.

[0081] While this subject matter has been shown and described with reference to its preferred embodiments, those skilled in the art will understand that many alternatives, modifications, and variations can be made therein without departing from its spirit and scope. Therefore, the invention is intended to encompass all alternatives, modifications, and variations that fall within the spirit and broad scope of the claims.

[0082] All publications, patents and patent applications mentioned in this specification are incorporated herein by reference in their entirety, to the same extent that each publication, patent or patent application is incorporated herein by reference individually and separately.

Claims

1. A process for preparing (I) Namodinosin include: (a) Protection of the hydroxyl group of 2,6-dichloropurine nucleoside diol of formula (II) Compound of formula (III) was obtained; (b) In the presence of an oxidizing agent, the compound of formula (III) is oxidized to obtain the compound of formula (IV); (c) Chloride the compound of formula (IV) to obtain the compound of formula (V); (d) Amination of compound (V) yields compound (VI); (e) Reacting compound (VI) with compound (VII) Compound of formula (VIII) was obtained; and (f) Deprotection treatment of compound (VIII).

2. The process according to claim 1, wherein the protection is carried out in the presence of an acid catalyst and 2-dimethylpropane.

3. The process according to claim 2, wherein the acid catalyst is p-toluenesulfonic acid.

4. The process according to any one of claims 1-3, wherein the oxidant is a percarboxylic acid.

5. The process according to claim 4, wherein the percarboxylic acid is selected from sodium periodate or potassium periodate.

6. The process according to any one of claims 1-5, wherein the oxidation is carried out in the presence of a ruthenium-containing catalyst and a solvent.

7. The process according to claim 6, wherein the ruthenium-containing catalyst is selected from the group consisting of metallic ruthenium, inorganic ruthenium salts, and organic ruthenium salts.

8. The process according to claim 7, wherein the ruthenium-containing catalyst is ruthenium chloride.

9. The process according to any one of claims 6-8, wherein the solvent in the oxidation step is a mixture of acetonitrile and water.

10. The process according to any one of claims 1-9, wherein the chlorination is carried out in the presence of a chlorinating agent and a polar aprotic solvent.

11. The process according to claim 10, wherein the chlorinating agent is thionyl chloride.

12. The process according to claim 10 or 11, wherein the polar aprotic solvent is acetonitrile.

13. The process according to any one of claims 1-12, wherein the amination is carried out in the presence of an amination agent.

14. The process according to claim 13, wherein the amination agent is methylamine.

15. The process according to any one of claims 1-14, wherein the chlorination and amination are carried out in the same pot without separating the (V) compound.

16. The process according to any one of claims 1-15, wherein the compound of formula (VIII) is not separated prior to the deprotection step.

17. The process according to any one of claims 1-16, wherein the formula (I) Namodnosen is recrystallized.

18. The process according to any one of claims 1-17, wherein the resulting compound of formula (I) has a purity of at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, or at least 99%.

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