Stereoselective fabrication of selected purine phosphoramidates

Abstract

The present invention relates to phosphoramidate nucleotide compound 1: The present invention provides a stereoselective method for producing TIFF2023538594000234.tif132170 or a pharmaceutically acceptable salt thereof.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 067,726, filed on August 19, 2020; U.S. Provisional Patent Application No. 63 / 074,302, filed on September 3, 2020; U.S. Provisional Patent Application No. 63 / 094,759, filed on October 21, 2020; and U.S. Provisional Patent Application No. 63 / 129,306, filed on December 22, 2020. The entire disclosures of these applications are hereby incorporated by reference in their entirety for all purposes.

[0002] The present invention provides a stereoselective method for producing purinophosphoramidate nucleotides and intermediates for their generation.

Background Art

[0003] Nucleoside analogs have been developed as effective therapeutic agents for many diseases including cancer, hepatitis C (HCV), hepatitis B (HBV), HIV, and human cytomegalovirus (HCMV). Nucleoside analogs have also been investigated for RNA virus infections including viruses of the Flaviviridae family (dengue virus, yellow fever virus, Zika virus), viruses of the Filoviridae family (Ebola virus, Marburg virus), and viruses of the Coronaviridae family (SARS - Cov - 1 (severe acute respiratory syndrome), SARS - CoV - 2 (COVID19), and MERS (Middle East respiratory syndrome coronavirus)).

[0004] Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, Patent Document 8, Patent Document 9, as well as Patent Document 10, Patent Document 11, Patent Document 12, and Patent Document 13 disclose pharmaceutically acceptable salts of Compound 1 or the hemisulfate of Compound 1, i.e., Compound 1 - A, which treat hepatitis C.

[0005] Patent documents 14 and 11 disclose compound 1 or pharmaceutically acceptable salts of compound 1 for treating certain flaviviruses, including dengue virus, West Nile virus, yellow fever virus, and Zika virus. [ka]

[0006] Patent documents 15 and 16 describe the use of compound 1 and compound 1-A for the treatment of SARS-CoV-2 (COVID-19).

[0007] Considering the importance of Compound 1 and Compound 1-A for the therapeutic treatment of humans infected with viruses such as flaviviruses, hepatitis C, or SARS-CoV-2, providing a method that is advantageous for scalable manufacturing is considered useful. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] U.S. Patent No. 9,828,410 [Patent Document 2] U.S. Patent No. 10,000,523 [Patent Document 3] U.S. Patent No. 10,005,811 [Patent Document 4] U.S. Patent No. 10,239,911 [Patent Document 5] U.S. Patent No. 10,519,186 [Patent Document 6] U.S. Patent No. 10,815,266 [Patent Document 7] U.S. Patent No. 10,870,672 [Patent Document 8] U.S. Patent No. 10,870,673 [Patent Document 9] U.S. No. 10,875,885 [Patent Document 10] International Application No. PCT / US16 / 21276 (International Publication No. WO 2016 / 144918) [Patent Document 11] International Application No. PCT / US2017 / 50323 (International Publication No. WO 2018 / 048937) [Patent Document 12] International Application No. PCT / US18 / 16301 (International Publication No. WO 2018 / 144640) [Patent Document 13] International Application No. PCT / US2019 / 26837 (International Publication No. WO 2019 / 200005) [Patent Document 14] U.S. Patent No. 10,946,033 [Patent Document 15] International Application No. PCT / US21 / 19468 [Patent Document 16] U.S. Patent No. 10,874,687 [Summary of the Invention]

[0009] The present invention is an advantageous and facile stereoselective method for the scalable production of phosphoramidate nucleotide compound 1, in which the S p -diastereomer (i.e., S-configuration at the chiral phosphorus atom) is present in substantially pure form, e.g., in substantially excess over the R p -diastereomer. A method is provided. [Chemical Formula]

[0010] A substantially pure form of a diastereomer typically refers to an S p -diastereomer that is about 90% or more with respect to the R p -diastereomer. In one embodiment, the substantially pure form is a purity of about 93% or more, about 95% or more, about 98% or more, or about 99% or more, or even 100% purity. In an alternative embodiment, the substantially pure form is about 80% or more, about 85% or more, or about 88% or more.

[0011] The S-stereochemistry of phosphorus is defined in the reaction of the nucleosides and phosphoramidates according to the invention. The production of the purine compound 1 according to the invention involves a coupling reaction of the dihydroquinine salt of phosphoramidic acid and the necessary purine nucleoside in the presence of the specific activators and bases described herein.

[0012] In a non-limiting and exemplary example of the present invention, a method for synthesizing the diastereomerically pure S p -phosphoramidate nucleotide is (a) contacting a nucleoside compound 2 with the dihydroquinine salt of isopropyl (hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of a benzotriazole-based or uronium-based activator such as HATU or COMU described herein or others, and a base, to obtain a diastereomer-enriched S p -diastereomer in substantially excess over the R p -diastereomer, and obtaining a diastereomer-enriched S p -phosphoramidate nucleotide compound 1; and

Chemical Formula

[0013] In certain embodiments, quinine as a salt or free base can be used in the preparation of dihydroquinine. In one embodiment, quinine hemisulfate monohydrate is used in the preparation of dihydroquinine.

[0014] In one embodiment, the activator is COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate). In the method of the present invention, COMU is an advantageous activator because it has low shock sensitivity. In the present invention, it has been found that when COMU is used as an activator in combination with the dihydrokinine salt of a phosphoramide and a base, compound 1 can be obtained in high isolation yield. Furthermore, the use of COMU as an activator can result in the preparation of compound 1 with high diastereoselectivity. By using COMU as an activator, it may also be possible to carry out the reaction efficiently and / or at a relatively low reaction temperature.

[0015] Alternatively, the above method can be carried out using activators such as benzotriazole-based activators, including, but not limited to, HOBt (1-hydroxybenzotriazole), PyBOP (benzotriazole-1-yloxytri(pyrrolidino)phosphonium hexafluorophosphate), HATU (O-(7-azabenzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate), HBTU (3-[bis(dimethylamino)methylumyl]-3H-benzotriazole-1-oxide hexafluorophosphate), HCTU (2-(6-chloro-1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium hexafluorophosphate), or TBTU (O-benzotriazole-1-yl-1,1,3,3-tetramethyluronium tetrafluoroborate). In one embodiment, the activator is HATU.

[0016] Examples 9, 10, and 12 below provide non-limiting examples of methods for producing compound 1, including the activator HATU, which can yield target compound 1 in high yield. Any impurities and by-products associated with the use of HATU can be removed by washing and selective crystallization of compound 1. By using HATU as an activator in the present invention, compound 1 can be obtained in high yield.

[0017] Example 13 illustrates a method for producing compound 1, which also includes the activator COMU, allowing target compound 1 to be obtained in high yield. Similarly, any impurities and by-products associated with the use of COMU can be removed by washing and selective crystallization of compound 1. Similar to HATU, the use of COMU as an activator in this invention allows compound 1 to be obtained in high yield.

[0018] In one embodiment, the base used in the coupling reaction is selected from NR3, where R can be independently selected from H, alkyl, aryl, heteroaryl, alkenyl, alkynyl, benzyl, and allyl, and NR3 typically has at least one, often two or three, non-hydrogen R groups. In one embodiment, the base is DIPEA (N,N-diisopropylethylamine) or NEt3 (triethylamine). Other non-limiting examples of the base are generally alkyl-substituted amines, or DABCO (1,4-diazabicyclo[2.2.2]octane), DBU (1,8-diazabicyclo[5.4.0]unde-7-ene), N-methylmorpholine, diethylamine, or monoethylamine. In an alternative embodiment, the base is quinine or quinidine. In one embodiment, the base is quinine.

[0019] Surprisingly, the dihydroquinine salt changes the stereochemistry of compound 1 during the coupling reaction. p -It was discovered that it helps direct the compound to form a diastereomer. In coupling reactions, tertiary amine bases are generally considered spectators of the bond formation event. The present invention, however, shows the unexpected result that dihydrokinin bases not only participate in the bond formation process but also direct it. Using this finding, we developed this method to give compound 1 in a substantially diastereomer-enriched form.

[0020] S p- Further purification of the diastereomer can be achieved by any method known to a skilled chemist that results in such purification, including, for example, (i) selective crystallization in a solvent or solvent / poor solvent system as described in more detail below, (ii) trituration of a poor solvent into a solvent-based solution of compound 1, or (iii) column chromatography. Exemplary details of the crystallization procedure are given below. Non-limiting examples of crystallization solvents are polar organic solvents such as alkyl esters, e.g., ethyl acetate or isopropyl acetate, acetonitrile, DMSO, methylene chloride, acetone, etc. Non-limiting examples of suitable poor solvents are non-polar organic liquids such as hydrocarbons that can be removed from the final product, including, but not limited to, pentane, hexane, heptane, etc.

[0021] Importantly, in certain embodiments, N is added during the reaction. 6 -methyl,N 2 This method can be achieved without the need for extra steps to protect the -amino-2,6-diaminopurine base, which is advantageous for the overall efficiency of the method. In the main embodiment, N in diaminopurine 6 -methyl or N 2 - The amino amine is neither protected nor substantially derivatized during the above method. This embodiment minimizes the need for derailing protection and / or deprotection steps.

[0022] In one embodiment, step (a) is carried out in a polar aprotic solvent, such as dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate (SiO), acetonitrile (MeCN), dimethyl sulfoxide (DMSO), acetone, or N-methylpyrrolidone. In one embodiment, step (a) is carried out in dichloromethane (DCM). In one embodiment, step (a) is carried out in 2-methyltetrahydrofuran (2-MeTHF). In several embodiments, step (a) is carried out in a mixture of solvents. In one embodiment, step (a) is carried out in a mixture of dichloromethane (DCM) and 2-methyltetrahydrofuran (2-MeTHF).

[0023] In one embodiment of the present invention, the production of compound 2 is as follows: (1.2.a) Protecting the 5'-hydroxyl and 3'-hydroxyl in the nucleoside (3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)-3-methyldihydrofuran-2(3H)-one to form a compound of formula I (wherein R 1a and R 1b It is an oxygen protecting group, and R 1a and R 1b At least one of them is a carbonate, e.g., -C(O)OC 1~6 Alkyl (e.g., -C(O)OCH3 or -C(O)OtBu), -C(O)O-benzyl, or -CH2-phenyl, where the phenyl group is substituted with at least one substituent selected from alkoxy (but not limited to methoxy and ethoxy), hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl, or in alternative embodiments, R 1a and R 1b At least one of them is -C(O)OC 1~20 Alkyl, -C(O)OC 2~20 Alkenyl, or -C(O)NR 10a R 10b And here, R 10a and R10b These are, independently, hydrogen and C 1~20 Alkyl, C 2~20 Selected from alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl, where C 1~20 Alkyl, C 2~20 The steps include obtaining an alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl (which may optionally be substituted with at least one substituent selected from alkoxy (but not limited to methoxy and ethoxy), hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl), [ka] (1.2.b) A step of converting the alcohol of formula I to a monofluoride by stereochemical inversion to obtain the compound of formula II, [ka] (1.2.c) A step of reducing the lactone of the nucleoside compound of formula II to obtain the nucleoside compound of formula III, [ka] (1.2.d) A step of converting the compound of formula III to the compound of formula IV, [ka] (In the formula, X is Cl, Br, or OAc) (1.2.e) A step of obtaining compound V by nucleophilically substituting the compound of formula IV with 2-amino-6-chloropurine, [ka] (1.2.f) 2-amino-6-chloropurine base to 2-amino-N 6 - The process involves converting to a methyl base and deprotecting the 3' and 5' positions to obtain compound 2. [ka] Includes.

[0024] In one embodiment, compound 2 is R 1a and R 1b ga-C(O)O- t The Bu group, or "Boc" group, is obtained in the following way: [ka] It is prepared via [method].

[0025] The dicarbonate product from step 1 above can be carried over without purification. Alternatively, in one embodiment of the present invention shown in Example 13, the product from step 1 can be purified by selective crystallization. By crystallizing the product in the mixture of DCM and n-heptane, a pure compound can be obtained and used in the next step to reduce the number of impurities.

[0026] Another aspect of the present invention is a novel dicarbonate intermediate in step 1, which can optionally be used in crystalline form. Isolating the pure compound in crystalline form provides an additional opportunity to control impurities and monitor the process. [ka]

[0027] Furthermore, the following dicarbonate intermediates are also novel intermediate compounds: [ka]

[0028] The product mixture from step 2 can also be purified by selective crystallization of the dicarbonate product, thereby providing yet another opportunity for control and monitoring. Alternatively, in some embodiments of the present invention, the product mixture from step 2 is carried over to step 3 without isolation. This has been found not to affect the final yield or purity of compound 2.

[0029] An additional aspect of the present invention describes obtaining compound 2 by deprotecting the Boc group under basic conditions. Deprotection under basic conditions makes it possible to prepare the product for coupling to a phosphoramidate prodrug, following purification by selective crystallization. Using acidic conditions, which are more typically used for deprotecting the Boc group, may require an additional step of neutralizing the salt and purifying the compound 2 for the introduction of the phosphoramidate prodrug.

[0030] The diastereomer-enriched phosphoramidate compound 1 prepared by this method is S p diastereomer R p S is present in greater excess than diastereomers. p Diastereomer:R p It may be a mixture of diastereomers. In one embodiment, S in diastereomer-enriched phosphoramide compound 1 p Diastereomer:R p The ratios of diastereomers are approximately 51:49, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, 98:2, or 99:1.

[0031] In certain embodiments, the above method may include a step of purifying a concentrated mixture of compound 1. A non-limiting example is the selective crystallization of the concentrated mixture in a suitable solvent. Non-limiting examples include alkyl acetate solvents such as ethyl acetate or isopropyl acetate, chlorinated solvents such as dichloromethane, ketone solvents such as acetone, aromatic solvents such as toluene, or mixtures thereof. In some embodiments, purification is carried out via selective crystallization in an alkyl acetate solvent, for example, isopropyl acetate. In one embodiment, purification is carried out via selective crystallization from a solvent, for example, alkyl acetate, a chlorinated solvent, a ketone solvent, or a mixture thereof, using a poor solvent, for example, acetonitrile or an aliphatic hydrocarbon. In one embodiment, purification is carried out via selective crystallization from a mixture of ethyl acetate and toluene.

[0032] In certain embodiments of the present invention, compound 1 is prepared as a pharmaceutically acceptable salt, for example, by reaction with a pharmaceutically acceptable acid, as described more fully herein.

[0033] In one embodiment, the pharmaceutically acceptable salt form of compound 1 is the hemisulfate form, i.e., compound 1-A: [ka] That is the case.

[0034] In one embodiment of the present invention, the production of the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate is (1.1.a) A step of coupling phenyl dichlorophosphate with benzyl alcohol to produce benzylphenyl phosphorochloride in situ, and then reacting this with L-alanine isopropyl ester hydrochloride to obtain isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate, [ka] (1.1.b) A step of debenzylation of isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate and in situ reduction of the kinin to obtain the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate, [ka] Includes.

[0035] In the alternative embodiment of (1.1.b), the kinin is reduced to dihydroquinone in a separate reaction. [ka]

[0036] In certain embodiments, free kinin bases can be used in the preparation of dihydrokinin. In one embodiment, kinin hemisulfate monohydrate is used in the preparation of dihydrokinin. [ka]

[0037] Next, the independently reduced dihydroquinine can optionally be added to the debenzylation reaction after purification. Although an additional step is required, this method has been found to produce the dihydroquinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in high yield and high purity.

[0038] In one embodiment, compound 2 is R 1a and R 1b The following method is used to determine if the group is a -C(O)O-benzyl group, i.e., a "carboxybenzyl" (Cbz) group: [ka] It is prepared via [method].

[0039] In an alternative embodiment, compound 2 is R 1aand R 1b The following methods assume that is -C(O)OCH3: [ka] It is prepared via [method].

[0040] In a further alternative embodiment, the preparation of compound 2 is as follows: (1.2.a) A step of protecting the nucleoside (3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)-3-methyldihydrofuran-2(3H)-one with a 3'-hydroxyl group and a 5'-hydroxyl group, Here, the protecting group connects the 3'-hydroxyl group and the 5'-hydroxyl group to form a cross-linking structure, and [ka] Bridge structures are [ka] Selected from, where the phenyl group of the crosslinked structure may be substituted with substituents selected from alkoxy (including, but not limited to, methoxy and ethoxy), hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl; (1.2.b) A step of converting the alcohol of formula I' to a monofluoride by stereochemical inversion to obtain the compound of formula II', [ka] (1.2.c) A step of reducing the lactone of the nucleoside compound of formula II' to obtain the nucleoside compound of formula III', [ka] (1.2.d) A step of converting the compound of formula III' to the compound of formula IV', [ka] (In the formula, X is Cl, Br, or OAc) (1.2.e) A step of obtaining a compound of formula V' by nucleophilically substituting the compound of formula IV' with 2-amino-6-chloropurine, [ka] (1.2.f) 2-amino-6-chloropurine base to 2-amino-N 6 - The process involves converting to a methyl base and deprotecting the 3' and 5' positions to obtain compound 2. [ka] Includes.

[0041] In an alternative embodiment, compound 2 is prepared by the following method: [ka] It can be prepared via [method].

[0042] In one embodiment, compound 1 and compound 1-A are used with compound 2 in the following way: [ka] It is prepared via [method].

[0043] In an alternative embodiment, compound 1 and compound 1-A are used with compound 2 in the following way: [ka] It is prepared via [method].

[0044] In an alternative embodiment, the coupling of compound 2 with the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate is carried out in the presence of the benzotriazole activator HATU and the kinin of the base: [ka]

[0045] In an alternative embodiment, the coupling of compound 2 with the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate is carried out in the presence of COMU as an activator and the kinin of the base: [ka]

[0046] In another embodiment, the present invention relates to the dihydroquinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate: [ka] To provide.

[0047] The dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate provides diastereoselectivity to coupling reactions using activators and bases. Despite starting from the racemic phosphorus atom in the prodrug precursor, using a chiral tertiary amine results in virtually S p -A concentrated product is generated. This unexpected effect makes the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate favorable for the formation of compound 1.

[0048] In another embodiment, the present invention also provides carbonate or carbamate compounds of formulas IIA and IIIA, and crosslinked compounds of formulas II' and III', or pharmaceutically acceptable salts thereof: [ka] During the ceremony, R 2a and R 2b It is an oxygen protecting group, and R 2a and R 2b At least one of them is -C(O)OC 1~6Alkyl (e.g., -C(O)OtBu or -C(O)OCH3) or -C(O)O-benzyl, or in alternative embodiments, R 2a and R 2b At least one of them is -C(O)OC 1~20 Alkyl, -C(O)OC 2~20 Alkenyl, or -C(O)NR 10a R 10b And here, R 10a and R 10b These are, independently, hydrogen and C 1~20 Alkyl, C 2~20 Selected from alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl, where R 2a and R 2b Each of these may be independently optionally substituted with substituents selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl groups, and The bridging structure in equations II' and III' is, [ka] Selected from, The phenyl group in the crosslinked structure may be substituted with substituents selected from alkoxy (including, but not limited to, methoxy and ethoxy), hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl groups.

[0049] In one embodiment, R 2a and R 2b Both are -C(O)OC 1~6 Alkyl, for example, -C(O)OtBu. In one embodiment, R 2a and R 2b Both are -C(O)O-benzyl. In one embodiment, R 2a is -C(O)OC 1~6 Alkyl or -C(O)O-benzyl, and R 2bis an oxygen protecting group which is an ester moiety, an ether moiety, or a silyl ether moiety when attached to oxygen. In an alternative embodiment, R 2b is -C(O)OC 1~6 alkyl or -C(O)O-benzyl, and R 2a is an oxygen protecting group which is an ester moiety, an ether moiety, or a silyl ether moiety when attached to oxygen.

[0050] In an alternative embodiment, R 2a and R 2b are both -C(O)OCH3. In one embodiment, R 2a is -C(O)OCH3, and R 2b is an oxygen protecting group which is an ester moiety, an ether moiety, or a silyl ether moiety when attached to oxygen. In an alternative embodiment, R 2b is -C(O)OCH3, and R 2a is an oxygen protecting group which is an ester moiety, an ether moiety, or a silyl ether moiety when attached to oxygen.

[0051] In an alternative embodiment, R 2a and R 2b are both -C(O)OC 1~20 alkyl, for example, -C(O)OC 1~6 alkyl, -C(O)OC 7~10 alkyl, -C(O)OC 11~14 alkyl, -C(O)OC 15~17 alkyl, or -C(O)OC 18~20 alkyl. In one embodiment, R 2a and R 2b are both -C(O)OC 16 H 33 In one embodiment, R 2a is -C(O)OC 16 H 33 and R 2b is an oxygen protecting group which is an ester moiety, an ether moiety, or a silyl ether moiety when attached to oxygen. In an alternative embodiment, R2b is -C(O)OC 16 H 33 And R 2a This is an oxygen protecting group, which, when bonded to oxygen, forms an ester, ether, or silyl ether moiety.

[0052] In an alternative embodiment, R 2a and R 2b Both are -C(O)OC 2~20 Alkenyls, for example, -C(O)OC 2~6 Alkenyl, -C(O)OC 6~10 Alkenyl, -C(O)OC 10~14 Alkenyl, -C(O)OC 14~18 Alkenyl, or -C(O)OC 18~20 It is an alkenyl. In one embodiment, R 2a and R 2b Both are -C(O)OC 2~20 It is an alkenyl. In one embodiment, R 2a is -C(O)OC 2~20 It is an alkenil and also R 2b This is an oxygen protecting group, which, when bonded to oxygen, is an ester, ether, or silyl ether moiety. In an alternative embodiment, R 2b is -C(O)OC 2~20 It is an alkenil and also R 2a This is an oxygen protecting group, which, when bonded to oxygen, forms an ester, ether, or silyl ether moiety.

[0053] In an alternative embodiment, R 2a and R 2b Both are -C(O)NR 10a R 10b , for example, -C(O)NHPh, -C(O)NHBn, -C(O)N(Ph)2, -C(O)N(Bn)2, -C(O)NHC 1~20 Alkyl (not limited to, but including -C(O)NHCH3, -C(O)NHtBu, and -C(O)NHC) 16 H 33 (including), and -C(O)N(C 1~20Alkyl)2 (not limited to, but including -C(O)N(CH3)2, -C(O)N(tBu)2, and -C(O)N(C 16 H 33 )2 is included. In one embodiment, R 2a and R 2b Both are -C(O)NR 10a R 10b In one embodiment, R 2a is -C(O)NR 10a R 10b And R 2b This is an oxygen protecting group, which, when bonded to oxygen, is an ester, ether, or silyl ether moiety. In an alternative embodiment, R 2b is -C(O)NR 10a R 10b And R 2a This is an oxygen protecting group, which, when bonded to oxygen, forms an ester, ether, or silyl ether moiety. [Brief explanation of the drawing]

[0054] [Figure 1] This is a diffractogram collected for the sample of compound 1-A obtained from Experiment 1 in Example 13. The X-axis is on a degree scale, while the Y-axis shows the intensity in counts. Further details are shown in Table 3 of Example 14. [Figure 2] This is a diffractogram collected for the sample of compound 1-A obtained from Experiment 2 in Example 13. The X-axis is on a degree scale, while the Y-axis shows the intensity in counts. Further details are shown in Table 4 of Example 14. [Figure 3] This is a diffractogram collected for the sample of compound 1-A obtained from Experiment 3 in Example 13. The X-axis is on a degree scale, while the Y-axis shows the intensity in counts. Further details are shown in Table 5 of Example 14. [Figure 4]This is a thermogram collected for a sample of compound 1-A obtained from Experiment 1 in Example 13. The X-axis represents the degree Celsius scale, while the Y-axis displays the heat flow in milliwatts. Further details are shown in Example 15. [Figure 5] This is a thermogram collected for a sample of compound 1-A obtained from Experiment 2 in Example 13. The X-axis represents the degree Celsius scale, while the Y-axis displays the heat flow in milliwatts. Further details are shown in Example 15. [Figure 6] This is a thermogram collected for a sample of compound 1-A obtained from Experiment 3 in Example 13. The X-axis represents the degree Celsius scale, while the Y-axis displays the heat flow in milliwatts. Further details are shown in Example 15. [Figure 7] This figure shows the reaction scheme for forming compound 1 from compound 2 and the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of an activator and a base. [Modes for carrying out the invention]

[0055] The present invention is a stereoselective method for producing purine phosphoramide nucleotide compound 1, and S p - Diastereomers, in a substantially pure form, for example, R p - Provides a method for addressing the excess presence of diastereomers: [ka]

[0056] The substantially pure form of a diastereomer is R p - Approximately 90% or more of S relative to diastereomers p - Refers to diastereomers. In one embodiment, a substantially pure form has a purity of about 93% or higher, about 95% or higher, about 98% or higher, about 99% or higher, or even 100%. In an alternative embodiment, a substantially pure form has a purity of about 80% or higher, about 83% or higher, about 85% or higher, or about 88% or higher.

[0057] In one embodiment, compound 1 is prepared as a pharmaceutically acceptable salt, for example, by reaction with a pharmaceutically acceptable acid, as described more fully herein.

[0058] In one embodiment, the pharmaceutically acceptable salt form of compound 1 is the hemisulfate form, i.e., compound 1-A: [ka] That is the case.

[0059] In one embodiment, compound 1-A is prepared by dropwise adding concentrated H2SO4 in ¼ or MeOH to compound 1 and filtering the resulting precipitate. In an alternative embodiment, compound 1-A is prepared by dropwise adding concentrated H2SO4 in acetone to compound 1.

[0060] In one embodiment of the present invention, a diastereomer of compound 1, pure S p -Methods for synthesizing phosphoramidate nucleotides are, (a) The nucleoside compound of compound 2 is brought into contact with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of the specified activator and the specified base, S p - diastereomer is R p - Diastereomer-enriched S, which is substantially in excess of diastereomers. p - A step to obtain phosphoramidate nucleotide compound 1, [ka] (b) Optionally, diastereomer-enriched S p -Phosphoramide nucleotide compound 1 is further purified, for example by selective crystallization, to obtain diastereomerally pure S with a diastereomer purity of over 90%, or even over 95%, or even over 99%.p - The process of obtaining compound 1, Includes.

[0061] Any additional optional steps are: (c) Diastereomerically pure S p - A step of preparing a pharmaceutically acceptable salt form of purine phosphoramide nucleotide compound 1, Includes.

[0062] In one embodiment, the activator is COMU((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate).

[0063] In one embodiment, the activator is HATU(O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate).

[0064] In some embodiments, alternative activators, typically but not limited to, benzotriazole-based activators including HOBt (1-hydroxybenzotriazole), PyBOP (benzotriazole-1-yloxytri(pyrrolidino)phosphonium hexafluorophosphate), HBTU (3-[bis(dimethylamino)methylumyl]-3H-benzotriazole-1-oxidehexafluorophosphate), HCTU (2-(6-chloro-1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium hexafluorophosphate), and TBTU (O-benzotriazole-1-yl-1,1,3,3-tetramethyluronium tetrafluoroborate).

[0065] In one embodiment, the base is selected from NR3, where R can be independently selected from H, alkyl, aryl, heteroaryl, alkenyl, alkynyl, benzyl, and allyl, which typically have at least one, often two or more, non-hydrogen R groups. In one embodiment, the base is DIPEA (N,N-diisopropylethylamine). In one embodiment, the base is NEt3 (triethylamine). In alternative embodiments, the base is selected from DMAP, (S)-C5Ph5-DMAP, (R)-C5Me5-DMAP, quinidine, quinine, TEA, DBU, TMEDA, imidazole, and K2CO3. In one embodiment, the base is quinine. In one embodiment, the base is dihydroquinine.

[0066] In some embodiments, the specified activator is a uronium-type activator selected from HBTU, HATU, COMU, and TFFH, and the base is DIPEA. In one embodiment, the activator is COMU and the base is NEt3. In another embodiment, the activator is COMU and the base is DIPEA.

[0067] In some embodiments, the identified activator is a benzotriazole-based activator selected from HOBt, PyBOP, HATU, HBTU, HCTU, and TBTU, and the base is DIPEA. In one embodiment, the activator is a benzotriazole-based activator selected from HOBt, PyBOP, HATU, HBTU, HCTU, and TBTU, and the base is NEt3. In one embodiment, the activator is HATU, and the base is DIPEA. In one embodiment, the activator is HATU, and the base is NEt3.

[0068] In some embodiments, the specified activator is a uronium-type activator selected from HBTU, HATU, COMU, and TFFH, and the base is a kinin. In one embodiment, the activator is COMU, and the base is a kinin. In another embodiment, the activator is COMU, and the base is a dihydrokinin or a kinin.

[0069] In some embodiments, the specified activator is a benzotriazole-based activator selected from HOBt, PyBOP, HATU, HBTU, HCTU, and TBTU, and the base is kinin, or a salt or salt hydrate thereof. In one embodiment, the activator is a benzotriazole-based activator selected from HOBt, PyBOP, HATU, HBTU, HCTU, and TBTU, and the base is kinin. In one embodiment, the activator is HATU, and the base is dihydrokinin. In one embodiment, the activator is HATU, and the base is kinin.

[0070] In one embodiment, step (a) is carried out in a polar aprotic solvent comprising dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate (SiO), acetonitrile (MeCN), dimethyl sulfoxide (DMSO), acetone, and N-methylpyrrolidone. In one embodiment, the solvent in step (a) is DCM. In one embodiment, the solvent in step (a) is 2-MeTHF. In several embodiments, the solvent in step (a) is a mixture of solvents. In one embodiment, the solvent in step (a) is a mixture of DCM and 2-MeTHF.

[0071] The temperature for each step of the reaction or purification is selected independently. In some embodiments, step (a) is carried out at about -20°C or below. In some embodiments, step (a) is carried out at about 0°C or below. In some embodiments, step (a) is carried out at about 10°C or below. In some embodiments, step (a) is carried out between about 10°C and about 30°C. In some embodiments, step (a) is carried out at about 30°C or above. In some embodiments, step (a) is carried out at about 50°C or above. In some embodiments, step (a) is carried out at about 70°C or above. Step (a) can be carried out at any temperature that achieves the desired result.

[0072] Process (a) results in S p - diastereomer is R p -A diastereomer-enriched phosphoramidate compound 1 is obtained, which is present in excess of the diastereomer. In one embodiment, S in diastereomer-enriched compound 1 p Diastereomer:R p The ratios of diastereomers are approximately 51:49, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, 98:2, or 99:1.

[0073] In one embodiment, the purification in step (b) is performed by selective crystallization of the concentrated mixture in, for example, an alkyl acetate solvent such as ethyl acetate or isopropyl acetate, a chlorinating solvent such as dichloromethane, a ketone solvent such as acetone, an aromatic solvent such as toluene, or a mixture thereof, to obtain pure S p - The objective is to obtain compound 1. In one embodiment, purification is carried out by selective crystallization from alkyl acetate such as isopropyl acetate. In a particular embodiment, purification is carried out by selective crystallization from a mixture of ethyl acetate and toluene.

[0074] In one embodiment, the purification in step (b) is the selective crystallization of the concentrated mixture, in which the concentrated mixture is dissolved in an organic solvent, and then a poor solvent is added dropwise to the solution system, where the organic solvent is C 1~8 Alcohol, C 2~8 Ether, C 3~7 Ketones, C 3~7 Ester, C 1~2 Chlorocarbon, and C 2~7 It contains a solvent selected from nitriles, and the poor solvent is C 5~12 Saturated hydrocarbons, C 6~12 The solvent is selected from aromatic hydrocarbons and petroleum ethers. In one embodiment, the organic solvent is selected from ethyl acetate, tert-butyl methyl ether, isopropanol, or tetrahydrofuran. In one embodiment, the poor solvent is selected from petroleum ether or hexane.

[0075] In one embodiment, the diastereomerically pure compound 1 has a purity of over 95%, over 96%, over 98%, over 99%, or 100%.

[0076] In one embodiment of the present invention, the method for synthesizing the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate is as follows: (1.a) A step of coupling phenyl dichlorophosphate with benzyl alcohol to produce benzylphenyl phosphorochloride in situ, and then reacting this with L-alanine isopropyl ester hydrochloride to obtain isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate, [ka] (1.b) A step of debenzylation of isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate and in situ reduction of the kinin to obtain the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate, [ka] Includes.

[0077] In one embodiment, debenzylation of isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate and in situ reduction of kinin are carried out in the presence of Pd / C and H2. In an alternative embodiment, debenzylation and reduction are carried out in the presence of a metal catalyst and H2. In an additional alternative embodiment, debenzylation and reduction are carried out in the presence of a metal catalyst and a reducing agent. Suitable reducing agents for the conversion include, but are not limited to, formates, hantchu esters and their derivatives, and cyclohexadienes and their derivatives.

[0078] In an alternative embodiment, debenzylation of isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate is carried out in the presence of dihydrokinin to obtain the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate: [ka]

[0079] In certain embodiments, the dihydroquinine added to the debenzylation reaction is prepared separately by reduction of the kinin. [ka]

[0080] In certain embodiments, the kinin reduced to dihydrokinin is a salt. In certain embodiments, this salt is a hemisulfate. In certain embodiments, the kinin is a hemisulfate monohydrate.

[0081] In certain embodiments, separately preparing the dihydroquinine used in step (1.b) results in improved impurity control.

[0082] In some embodiments, step (1.a) is carried out in an isopropyl acetate solvent. In some embodiments, step (1.a) is carried out in an alkyl acetate solvent. In some embodiments, step (1.a) is carried out in a polar aprotic organic solvent. Suitable alternative solvents for use in step (Ia) include, but are not limited to, dichloromethane, acetonitrile, tetrachloroethane, benzene, chlorobenzene, toluene, trifluorotoluene, isopropyl acetate, ethyl acetate, tetrahydrofuran, diethyl ether, methyl tertiary butyl ether, dimethoxyethane, dimethylacetamide, and N-methyl-2-pyrrolidone.

[0083] Step (1.a) can be carried out below room temperature. In certain embodiments, step (1.a) is carried out at about -70°C or below. In certain embodiments, step (1.a) is carried out at about -50°C or below. In certain embodiments, step (1.a) is carried out at about -30°C or below. In certain embodiments, step (1.a) is carried out at about -10°C or below. In certain embodiments, step (1.a) is carried out at about 0°C or below. In certain embodiments, step (1.a) is carried out at about 20°C or below. Alternatively, step (1.a) can be carried out at any temperature that achieves the desired result.

[0084] In some embodiments, the debenzylation step of step (1.b) is carried out in an isopropyl alcohol solvent. In some embodiments, debenzylation is carried out in an alkyl alcohol solvent. In some embodiments, benzylation is carried out in a polar protic solvent. In some embodiments, benzylation is carried out in a polar solvent. Suitable alternative solvents for use in step (1.b) include, but are not limited to, water, methanol, ethanol, n-propyl alcohol, butanol, pentanol, hexanol, dimethyl sulfoxide, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethoxyethane, dimethyl carbonate, acetonitrile, and N-methyl-2-pyrrolidone.

[0085] Step (1.b) can be carried out at any temperature that achieves the desired result. In some embodiments, step (1.b) is carried out at about -20°C or below. In some embodiments, step (1.b) is carried out at about 0°C or below. In some embodiments, step (1.b) is carried out at about 10°C or below. In some embodiments, step (1.b) is carried out between about 10°C and about 30°C. In some embodiments, step (1.b) is carried out at about 30°C or above. In some embodiments, step (1.b) is carried out at about 50°C or above. In some embodiments, step (1.b) is carried out at about 70°C or above.

[0086] In a further embodiment of the present invention, the method for synthesizing compound 2 is as follows: Step 1 (1.2.a): Protect the 5'-hydroxyl and 3'-hydroxyl of the nucleoside (3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)-3-methyldihydrofuran-2(3H)-one to form a carbonate compound or carbamate compound of formula I (wherein R 1a and R 1b It is an oxygen protecting group, and R 1a and R 1b At least one of them is -C(O)OC 1~6Alkyl, -C(O)O-benzyl, or -CH2-phenyl, where the phenyl group is substituted or, in alternative embodiments, R 1a and R 1b At least one of them is -C(O)OC 1~20 Alkyl, -C(O)OC 2~20 Alkenyl, or -C(O)NR 10a R 10b And here, R 10a and R 10b These are, independently, hydrogen and C 1~20 Alkyl, C 2~20 A step to obtain a compound selected from alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl, wherein the aryl, arylalkyl, heteroaryl, and heteroarylalkyl may optionally be substituted with at least one substituent selected from alkoxy (but not limited to methoxy and ethoxy), hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl. Includes: [ka]

[0087] In one embodiment, R 1a and R 1b At least one of the groups is -CH2-phenyl, where the phenyl group is substituted with at least one substituent selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl groups.

[0088] Non-limiting examples of substituted benzyl ether moieties include p-methoxybenzyl, 3,4-dimethoxybenzyl, 2,4-dimethoxybenzyl, 2-hydroxybenzyl, 3,4-dimethoxybenzyl, 2,3,4-trimethoxybenzyl, 3,4,5-trimethoxybenzyl, 2,5-dimethoxybenzyl, o-nitrobenzyl, p-nitrobenzyl, p-bromobenzyl, p-chlorobenzyl, 2,6-dichlorobenzyl, p-phenylbenzyl, 2,6-difluorobenzyl, p-azidobenzyl, 2-trifluorobenzyl, and 4-azido-3-chlorobenzyl.

[0089] In one embodiment, R 1a and R 1b At least one of them is -C(O)OC 1~6 Alkyl, for example, -C(O)OtBu or -C(O)O-benzyl. In an alternative embodiment, R 1a and R 1b At least one of them is -C(O)OCH3. In an alternative embodiment, R 1a and R 1b Both are -C(O)OCH3.

[0090] In one embodiment, R 1a is -C(O)OC 1~6 Alkyl, -C(O)O-benzyl, or -CH2-phenyl, where the phenyl group is substituted and R 1b This is an oxygen protecting group, which, when bonded to oxygen, is an ester, ether, or silyl ether moiety. In an alternative embodiment, R 1b is -C(O)OC 1~6 Alkyl, -C(O)O-benzyl, or -CH2-phenyl, where the phenyl group is substituted and R 1a This is an oxygen protecting group, which, when bonded to oxygen, forms an ester, ether, or silyl ether moiety.

[0091] In an alternative embodiment, R 1a and R 1bAt least one of them is -C(O)OC 1~18 Alkyl, -C(O)OC 1~16 Alkyl, -C(O)OC 1~14 Alkyl, -C(O)OC 1~12 Alkyl, -C(O)OC 1~10 Alkyl, -C(O)OC 1~8 Alkyl, -C(O)OC 1~6 Alkyl, -C(O)OC 1~4 Alkyl, -C(O)OC 1~2 Alkyl, -C(O)OC 2~20 Alkyl, -C(O)OC 4~20 Alkyl, -C(O)OC 6~20 Alkyl, -C(O)OC 8~20 Alkyl, -C(O)OC 10~20 Alkyl, -C(O)OC 12~20 Alkyl, -C(O)OC 14~20 Alkyl, -C(O)OC 16~20 Alkyl and -C(O)OC 18~20 Alkyl-containing -C(O)OC 1~20 It is alkyl. In one embodiment, R 1a and R 1b Both are -C(O)OC 1~20 It is alkyl. In one embodiment, R 1a and R 1b Both are -C(O)OC 16 H 33 That is the case.

[0092] In an alternative embodiment, R 1a and R 1b Both are -C(O)NR 10a R 10b , for example, -C(O)NHPh, -C(O)NHBn, -C(O)N(Ph)2, -C(O)N(Bn)2, -C(O)NHC 1~20 Alkyl (not limited to, but including -C(O)NHCH3, -C(O)NHtBu, and -C(O)NHC) 16 H 33 (including), and -C(O)N(C 1~20Alkyl)2 (not limited to, but including -C(O)N(CH3)2, -C(O)N(tBu)2, and -C(O)N(C 16 H 33 )2 is included). In one embodiment, R 1a and R 1b Both are -C(O)NR 10a R 10b In one embodiment, R 1a is -C(O)NR 10a R 10b And R 1b This is an oxygen protecting group, which, when bonded to oxygen, is an ester, ether, or silyl ether moiety. In an alternative embodiment, R 1b is -C(O)NR 10a R 10b And R 2a This is an oxygen protecting group, which, when bonded to oxygen, forms an ester, ether, or silyl ether moiety.

[0093] In one embodiment, R 1a and R 1b At least one of them is -C(O)NHC 1~18 Alkyl, -C(O)NHC 1~16 Alkyl, -C(O)NHC 1~14 Alkyl, -C(O)NHC 1~12 Alkyl, -C(O)NHC 1~10 Alkyl, -C(O)NHC 1~8 Alkyl, -C(O)NHC 1~6 Alkyl, -C(O)NHC 1~4 Alkyl, -C(O)NHC 1~2 Alkyl, -C(O)NHC 2~20 Alkyl, -C(O)NHC 4~20 Alkyl, -C(O)NHC 6~20 Alkyl, -C(O)NHC 8~20 Alkyl, -C(O)NHC 10~20 Alkyl, -C(O)NHC 12~20 Alkyl, -C(O)NHC 14~20 Alkyl, -C(O)NHC 16~20 Alkyl and -C(O)NHC 18~20-C(O)NHC containing alkyl 1~20 It is alkyl. In one embodiment, R 1a and R 1b Both are -C(O)NHC 1~20 It is alkyl. In one embodiment, R 1a and R 1b Both are -C(O)NHC 16 H 33 That is the case.

[0094] This process may be carried out according to one of the procedures for hydroxyl protection described in Theodora W. Green, Protective Groups in Organic Synthesis, Third Edition, John Wiley & Sons (1999) (which is incorporated herein by reference). For example, R 1a and / or R 1b When is -CH2-phenyl, and the phenyl group is substituted, the compound of formula I can be prepared according to the conditions described on pages 76 to 99 of the document. 1a and / or R 1b When is -C(O)OCH3, the compound of formula I can be prepared using ClC(O)OCH3 in a suitable solvent such as triethylamine and THF.

[0095] In an alternative embodiment, the 5'-hydroxyl group and the 3'-hydroxyl group in the nucleoside (3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)-3-methyldihydrofuran-2(3H)-one are protected by the R 1c and R 1d Protected by (here, R 1c and R 1d (When bonded to oxygen, it independently forms an ester, ether, or silyl ether moiety), yielding a compound of formula I': [ka]

[0096] For example, the protecting group when bonded to oxygen may be an ester moiety, such as a benzoate acetate. In one embodiment, the oxygen protecting group when bonded to oxygen is a silyl ether moiety (e.g., trimethylsilyl (TMS), triisopropylsilyl (TIPS), tert-butyldimethylsilyl (TBDMS or TBS), or tert-butyldiphenylsilyl (TBDPS)). In one embodiment, the oxygen protecting group when bonded to oxygen is an ether moiety, such as a methyl ether, methoxymethyl ether, or benzyl ether. These protecting groups may be introduced according to one of the procedures for protecting hydroxyls described in Theodora W. Green, Protective Groups in Organic Synthesis, Third Edition, John Wiley & Sons (1999) (which is incorporated herein by reference). For example, when the oxygen protecting group bonded to oxygen is the ester moiety, the compound of formula I can be prepared according to the conditions described on pages 149 to 178 of the document, and when the oxygen protecting group bonded to oxygen is the silyl ether moiety, the compound of formula I can be prepared according to the conditions described on pages 113 to 147 of the document. In one embodiment, the protecting group is a tert-butyldimethylsilyl (TBS) group. The TBS group is selectively introduced into primary alcohols rather than secondary alcohols using the conditions described on page 128 of the document and in Ogilvie et al. Can. J. Chem. 1979, 57, 2230. These conditions include the use of TBSCl, DMAP, and NEt3 in DMF at 25°C.

[0097] Non-limiting examples of additional protecting groups when bonded to oxygen include: bromobenzoate, p-methoxybenzyloxymethyl ether (MPBM), o-nitrobenzyloxymethyl ether (NBOM), p-nitrobenzyloxymethyl ether, t-butoxymethyl ether, 2,2,2-trichloroethoxymethyl ether, 3-bromotetrahydropyranyl ether, tetrahydropyranyl ether, tetrahydrothiopyranyl ether, 1-methoxycyclohexyl ether, 1,4-dioxan-2-yl ether, Other examples include tetrahydrofuranyl ether, tetrahydrothiofuranyl ether, substituted phenyl ether, 2-picolyl ether, 4-picolyl ether, 1,3-benzodithiolan-2-yl ether, p-chlorophenoxyacetic acid, 3-phenylpropionic acid, p-phenylbenzoic acid, alkyl p-nitrophenyl carbonyl, alkyl benzyl carbonyl, alkyl p-methoxybenzyl carbonyl, alkyl o-nitrobenzyl carbonyl, and alkyl p-nitrobenzyl carbonyl.

[0098] R 1a and R 1b A non-restrictive example of this is: [ka] These are some examples.

[0099] R 1a and R 1b An additional non-limiting example of this is: [ka] These are some examples.

[0100] R 1a and R 1b An additional non-limiting example of this is: [ka] These are some examples.

[0101] R 1aand R 1b An additional non-limiting example of this is: [ka] These are some examples.

[0102] In one embodiment, R 10a is hydrogen. In one embodiment, R 10a It is phenyl.

[0103] Non-limiting examples of carbonate compounds of formula I include: [ka] TIFF0007851034000049.tif253170 is one example.

[0104] Additional non-limiting examples of carbonate compounds of formula I include: [ka] These are some examples.

[0105] Additional non-limiting examples of carbonate compounds of formula I include: [ka] These are some examples.

[0106] Additional non-limiting examples of compounds of formula I include: [ka] These are some examples.

[0107] In one embodiment, R 10a is hydrogen. In one embodiment, R 10a It is phenyl.

[0108] Step (1.2.b): Using a suitable fluorinating agent such as Morpho-DAST, DAST, or SO2F2, the alcohol of formula I is converted to the corresponding fluoro derivative by stereochemical inversion to obtain the carbonate compound or carbamate compound of formula II: [ka]

[0109] In one embodiment, step (1.2.b) described herein is carried out using a sulfonyl fluoride / TREAT·HF mixture (SO2F2, NET3·3HF). In one embodiment, step (1.2.b) described herein is carried out using DAST (Et2NSF3). In one embodiment, step (1.2.b) described herein is carried out using Deoxo-Fluor®. In one embodiment, step (1.2.b) described herein is carried out using morpholinosulfur trifluoride (Morph-DAST). Alternatively, step (1.2.b) can be carried out using any fluorinating reagent that achieves the desired result.

[0110] In some embodiments, step (1.2.b) is performed at a temperature of about -70°C or lower. In some embodiments, step (1.2.b) is performed at a temperature of about -50°C or lower. In some embodiments, step (1.2.b) is performed at a temperature of about -10°C or lower. In some embodiments, step (1.2.b) is performed at a temperature of about 0°C or lower. In some embodiments, step (1.2.b) is performed at a temperature of about 10°C or lower. In some embodiments, step (1.2.b) is performed between about 10°C and about 30°C. In some embodiments, step (1.2.b) is performed at a temperature of about 30°C or higher. In some embodiments, step (1.2.b) is performed at a temperature of about 50°C or higher. Step (1.2.b) can be performed at any temperature that achieves the desired result.

[0111] In an alternative embodiment, the fluorination reaction proceeds primarily while maintaining stereochemistry at the 2' position. In this embodiment, the compound of formula I'' is reacted with a fluorinating reagent to obtain the compound of formula II: [ka]

[0112] When the product of a fluorination reaction is a mixture of "α-fluoro" lactone derivatives and "β-fluoro" lactone derivatives, these compounds can be separated by conventional methods known to those skilled in the art, such as column chromatography or crystallization, to isolate the desired stereochemistry ("α-fluoro" configuration).

[0113] Additional non-limiting examples of nucleophilic fluorinating reagents include pyridinium poly(hydrogen fluoride) (Olar's Reagent), nitrosonium tetrafluoroborate / pyridinium poly(hydrogen fluoride), triethylamine tris(hydrogen fluoride) (TREAT·HF), perfluoro-1-butanesulfonyl fluoride (PBSF), Jarovenko Reagent, Ishikawa Reagent, TFEDMA, N,N'-dimethyl-2,2-difluoroimidazolidine, 4-morpholinosulfate trifluoride, bromine trifluoride, and 4-tert-butyl-2,6-dimethylphenylsulfate trifluoride (Fluolead®). Fluorination reactions can be carried out according to the conditions described in Pankiewicz, K., Journal of Fluorine Chemistry, 1993, 64, 15-36; Hudlicky, M., “Fluorination with Diethylaminosulfur Trifluoride and related Aminofluorosulfuranes” in Organic Reactions, Vol. 35, 1998, 513-637; Singh et al. Synthesis, 2002, 17, 2561-2578; and Liang, Theresa, et al. Angewandte Chemie International Edition, 2013, 52, 8214-8264.

[0114] Step (1.2.c): A step of reducing the lactone of the nucleoside compound of formula II using a suitable reducing agent, such as Red-Al, DIBAL, LiAlH4, or NaBH4, to obtain the nucleoside compound of formula III; [ka]

[0115] Non-limiting reagents for the reduction of lactones described herein include DIBAL-H (diisobutylaluminum hydride), NaBH4, Red-Al (trademark) sodium bis(2-methoxyethoxy)aluminum hydride, and LiAlH4 (lithium aluminum hydride). Alternatively, the reduction of lactones can be achieved by metal reducing agents, but are not limited to, zinc, magnesium, copper, iron, sodium, potassium, and lithium. Any reducing agent that achieves the desired result can be used.

[0116] In some embodiments, step (1.2.c) is performed at a temperature of about -70°C or lower. In some embodiments, step (1.2.c) is performed at a temperature of about -50°C or lower. In some embodiments, step (1.2.c) is performed at a temperature of about -10°C or lower. In some embodiments, step (1.2.c) is performed at a temperature of about 0°C or lower. In some embodiments, step (1.2.c) is performed at a temperature of about 10°C or lower. In some embodiments, step (1.2.c) is performed between about 10°C and about 30°C. In some embodiments, step (1.2.c) is performed at a temperature of about 30°C or higher. In some embodiments, step (1.2.c) is performed at a temperature of about 50°C or higher. Step (1.2.c) can be performed at any temperature that achieves the desired result.

[0117] If the reduction product is a mixture of nucleosides having R-stereochemistry and S-stereochemistry at the hydroxyl group, these compounds can be separated by conventional methods known to those skilled in the art, such as column chromatography or crystallization, to isolate the desired stereochemistry. Alternatively, the mixture of diastereomers can be carried over to step (1.2.d) described herein to obtain the compound of formula IV as a mixture of diastereomers. In this embodiment, the compound of formula IV (as a mixture of diastereomers at the 1' position) is reacted with 2-amino-6-chloropurine to obtain the compound of formula V as a mixture of diastereomers. The diastereomer of formula V can be separated by conventional methods known to those skilled in the art, such as column chromatography or crystallization, to isolate the desired stereochemistry.

[0118] Step (1.2.d): Step of converting the compound of formula III to the compound of formula IV: [ka] (In the formula, X is Cl, Br, or OAc).

[0119] In one embodiment, the hydroxyl group is converted to Br using PPh3 and CBr4. In another embodiment, the hydroxyl group is converted to Br using PPh3 and dibromohydantoin. In yet another embodiment, the hydroxyl group is converted to Cl using PPh3 and CCl4. In yet another embodiment, the hydroxyl group is converted to OAc using ClC(O)CH3 and optionally NEt3. Step (1.2.d) can be accomplished by any chlorinating, brominating, or acetylating reagent that achieves the desired result.

[0120] In some embodiments, step (1.2.d) is carried out in a tetrahydrofuran solvent. In some embodiments, step (1.2.d) is carried out in an ether solvent. In some embodiments, step (1.2.d) is carried out in a nonpolar solvent. In some embodiments, step (1.2.d) is carried out in a polar protic solvent. Suitable solvents for use in step (1.2.d) include, but are not limited to, diethyl ether, methyl tertiary butyl ether, tetrahydrofuran, dimethoxyethane, methanol, ethanol, trifluoroethanol, propanol, butanol, pentanol, hexanol, pentane, hexane, heptane, benzene, toluene, trifluorotoluene, and xylene.

[0121] In some embodiments, step (1.2.d) is carried out at approximately -70°C or below. In some embodiments, step (1.2.d) is carried out at approximately -50°C or below. In some embodiments, step (1.2.d) is carried out at approximately -10°C or below. In some embodiments, step (1.2.d) is carried out at approximately 0°C or below. In some embodiments, step (1.2.d) is carried out at approximately 10°C or below. In some embodiments, step (1.2.d) is carried out between approximately 10°C and approximately 30°C. In some embodiments, step (1.2.d) is carried out at approximately 30°C or above. In some embodiments, step (1.2.d) is carried out at approximately 50°C or above. Step (1.2.d) can be carried out at any temperature that achieves the desired result.

[0122] Step (1.2.e): A step to obtain compound V by nucleophilically substituting the compound of formula IV with 2-amino-6-chloropurine: [ka]

[0123] In one embodiment, the nucleophilic substitution in step (1.2.e) described herein is carried out using a non-nucleophilic base. Non-limiting embodiments of the non-nucleophilic base for step (1.2.e) include sodium tert-pentoxide, potassium tert-pentoxide, sodium tert-butoxide, potassium tert-butoxide, lithium diisopropylamide, and lithium bis(trimethylsilyl)amide. In one embodiment, the base in step (1.2.e) described herein is sodium tert-butoxide or potassium tert-butoxide. In one embodiment, the base in step (1.2.e) described herein is sodium tert-pentoxide or potassium tert-pentoxide. Any base that achieves the desired result can be used in step (1.2.e).

[0124] In some embodiments, the reaction in step (1.2.e) is carried out in an acetonitrile solvent. In some embodiments, the solvent in step (1.2.e) is selected from acetonitrile, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, and dimethoxyethane. In some embodiments, the reaction in step (1.2.e) is carried out in a polar aprotic solvent.

[0125] In some embodiments, the compound of formula V can be purified from the crude reaction mixture by selective crystallization. In some embodiments, selective crystallization is carried out using a mixture of solvents. In some embodiments, the mixture of solvents used is a mixture of DCM and n-heptane.

[0126] In some embodiments, step (1.2.e) is performed between about 10°C and about 30°C. In some embodiments, step (1.2.e) is performed at about 30°C or higher. In some embodiments, step (1.2.e) is performed at about 50°C or higher. In some embodiments, step (1.2.e) is performed at about 70°C or higher. In some embodiments, step (1.2.e) is performed at about 90°C or higher. Step (1.2.e) can be performed at any temperature that achieves the desired result.

[0127] In a particular embodiment, the present invention has a structure: [ka] It contains a crystalline compound of formula V.

[0128] Step (1.2.f): 2-amino-6-chloropurine base to 2-amino-N 6 -The process involves converting to a methyl base and deprotecting the 3' and 5' positions to obtain compound 2: [ka]

[0129] In some embodiments, step (1.2.f) is carried out using methylamine. In some embodiments, the methylamine used is a solution in methanol. In some embodiments, the methylamine used is a solution in water.

[0130] In some embodiments, the reaction in step (1.2.f) is carried out in an acetonitrile solvent. In some embodiments, the solvent in step (1.2.f) is selected from acetonitrile, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dimethoxyethane, methanol, ethanol, propanol, butanol, pentanol, and hexanol. In some embodiments, the reaction in step (1.2.f) is carried out in a polar aprotic solvent. In some embodiments, the reaction in step (1.2.f) is carried out in a polar protic solvent.

[0131] In some embodiments, step (1.2.f) is performed between about 10°C and about 30°C. In some embodiments, step (1.2.f) is performed at about 30°C or higher. In some embodiments, step (1.2.f) is performed at about 50°C or higher. In some embodiments, step (1.2.f) is performed at about 70°C or higher. In some embodiments, step (1.2.f) is performed at about 90°C or higher. Step (1.2.f) can be performed at any temperature that achieves the desired result.

[0132] In some embodiments, step (1.2.f) comprises at least two more detailed steps, the product optionally purified between them. In certain embodiments, step (1.2.f) can be divided into two steps. In some embodiments of step (1.2.f), the compound of formula V is first converted to the compound of formula Va while retaining the alcohol protecting group. [ka]

[0133] The compound of formula Va is optionally purified by crystallization. In some embodiments, the crude compound of formula Va is carried over without further purification. In certain embodiments, it is advantageous to purify the intermediate compound of formula Va. In certain embodiments, the present invention has a structure: [ka] This includes crystalline compounds of formula Va.

[0134] In some embodiments of step (1.2.f), the compound of formula Va is deprotected to obtain compound 2. In certain embodiments, deprotection is carried out under acidic conditions. In certain embodiments, deprotection is carried out under basic conditions. When basic conditions are used for deprotection, the step of neutralizing the salt before the next reaction is not required. [ka]

[0135] In an alternative embodiment, as shown in step (1.2.f.1), the 2-amino-6-chloropurine base is replaced with 2-amino-N 6 -Converts to a methyl base and selectively deprotects the 5'-hydroxyl group: [ka]

[0136] In certain embodiments, the mixture of products obtained from step (1.2.f) can be proceeded to the next step without further purification. In certain embodiments, if the product from step (1.2.e) is purified, the mixture of products can be proceeded to the next step without further purification.

[0137] In this embodiment, the compound of formula VI is reacted with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of the specified activators and bases described herein, S p - diastereomer is R p - Protected diastereomers that are present in excess of the diastereomers, enriched by formula VII S p - Obtain phosphoramidate nucleotides: [ka]

[0138] In an alternative embodiment, the N of the nucleoside 2 The position is protected before phosphorylation. In this embodiment, N 2 -A compound of formula VIII in which the amine is protected is reacted with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of the specified activators and bases described herein, S p - diastereomer is R p - Protected diastereomer enriched in excess of diastereomers of formula IX p - Obtain phosphoramidate nucleotides: [ka]

[0139] In one embodiment, the preparation of the compound of formula VIII is as follows: (1.2.f.1) N in compounds of formula V 2 Protecting the position R 3a The process involves protecting the compound with a solution to obtain the compound of formula X, [ka] (In the formula, R 3a This is a nitrogen protecting group, which, when bonded to nitrogen, forms an amine, amide, or carbamate moiety. (1.2.g) The 6-chloro position in the compound of formula X is N 6 -Converted to a methylamino group, R 1a Position and R 1b The process involves deprotecting the position to obtain the compound of formula VIII, [ka] Includes.

[0140] In additional alternative embodiments, the N of the nucleoside 2 -amine and N 6-Protect methylamine before phosphorylation. In this embodiment, N 2 -amine and N 6 - A methylamine-protected compound of formula XI is reacted with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of the specified activators and bases described herein, S p - diastereomer is R p - Protected diastereomers that are present in excess of the diastereomers, enriched by formula XII S p - Obtain phosphoramidate nucleotides: [ka]

[0141] In one embodiment, the preparation of the compound of formula XI is carried out by N in the compound of formula VIII. 6 -Methylamine is protected by the protecting group R 3b This includes protecting the compound of formula XI with: [ka] (In the formula, R 3b This is a nitrogen protecting group, which, when bonded to nitrogen, forms an amine, amide, or carbamate moiety.

[0142] In an alternative embodiment, the N of the nucleoside 6 -Protect methylamine before phosphorylation. In this embodiment, N 6 - A methylamine-protected compound of formula XIII is reacted with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of the specified activators and bases described herein, S p - diastereomer is R p - Protected diastereomer enriched in excess of diastereomers of formula XIV p - Obtain phosphoramidate nucleotides: [ka]

[0143] In one embodiment, the preparation of the compound of formula XIII is carried out by N in compound 2. 6 -Methylamine is protected by the protecting group R 3b Protected by the compound of formula XIII (N 6 It is synthesized by obtaining the methylamine position: [ka]

[0144] In one embodiment, R 3a and R 3b These are, independently, nitrogen protecting groups that form a carbamate moiety when bonded to nitrogen, such as tert-butoxycarbonyl-(Boc) and benzyloxycarbonyl-(Cbz). In one embodiment, R 3a and R 3b R is independently a nitrogen protecting group that is an amine moiety when bonded to nitrogen, such as benzylamine or para-methoxybenzylamine. In some embodiments, R 3a and R 3b R 1 It is a protecting group similar to the one described herein and can be deprotected by the same methods as described herein. In one embodiment, R 3a and R 3b It is a benzylamine when bonded to nitrogen. The benzyl group can be formed and cleaved as described on pages 579-580 of Theodora W. Green, Protective Groups in Organic Synthesis, Third Edition, John Wiley & Sons (1999). For example, the benzyl group can be introduced using BnBr and NEt3 in CH3CN, and the benzyl group can be removed using Pd / C and HCOOH in CH3OH. In one embodiment, R 3a and R 3bThis is a tert-butoxycarbonyl-(Boc) group that is formed and cleaved independently, as described on pages 518-525 of Theodora W. Green, Protective Groups in Organic Synthesis, Third Edition, John Wiley & Sons (1999). For example, the tert-butoxycarbonyl group can be introduced using di-tert-butyl-dicarbonate and DMAP in MeCN and removed using catalyst DBU in MeOH.

[0145] Next, protected diastereomer enriched S of formula VII, formula IX, formula XII, or formula XIV p -Phosphoramide nucleotides are optionally further purified by selective crystallization, for example, to obtain diastereomers of formulas VII, IX, XII, or XIV, respectively, resulting in pure S p -Purin phosphoramide nucleotides (where the diastereomer purity is over 90%, 95%, or even over 99%) are obtained, and then deprotected to obtain diastereomerally pure S p - Obtain phosphoramidate nucleotide compound 1.

[0146] Next, in one embodiment, compound 1 is further purified and / or converted to a pharmaceutically acceptable salt, for example, compound 1-A.

[0147] In an alternative embodiment, the preparation of compound 2 includes steps (1.2.a) to (1.2.d): (1.2.a) A step of protecting the nucleoside (3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)-3-methyldihydrofuran-2(3H)-one with a 3'-hydroxyl group and a 5'-hydroxyl group. Here, the protecting group connects the 3'-hydroxyl group and the 5'-hydroxyl group to form a cross-linking structure, and [ka] Bridge structures are [ka] Selected from, where the phenyl group may be substituted with substituents selected from alkoxy (including, but not limited to, methoxy and ethoxy), hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl groups.

[0148] In an alternative embodiment, the bridge structure is, [ka] Selected from, where the phenyl group may be substituted with substituents selected from alkoxy (including, but not limited to, methoxy and ethoxy), hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl groups.

[0149] (1.2.b) A step to obtain the compound of formula II' by converting the alcohol of formula I' to a monofluoride through stereochemical inversion. [ka]

[0150] In one embodiment, step (1.2.b) described herein can be carried out using a sulfonyl fluoride / TREAT·HF mixture (SO2F2, NET3·3HF). In one embodiment, step (1.2.b) described herein can be carried out using DAST (Et2NSF3). In one embodiment, step (1.2.b) described herein can be carried out using Deoxo-Fluor™. In one embodiment, step (1.2.b) described herein can be carried out using morpholinosulfur trifluoride (Morph-DAST).

[0151] In an alternative embodiment, the fluorination reaction can proceed while maintaining stereochemistry primarily at the 2' position. In this embodiment, the compound of formula XV is reacted with a fluorinating reagent to obtain the compound of formula II': [ka]

[0152] When the product of a fluorination reaction is a mixture of "α-fluoro" lactone derivatives and "β-fluoro" lactone derivatives, these compounds can be separated by conventional methods known to those skilled in the art, such as column chromatography or crystallization, to isolate the desired stereochemistry ("α-fluoro" configuration).

[0153] Step (1.2.c): A step in which the lactone of the nucleoside compound of formula II' is reduced using a suitable reducing agent, such as Red-Al, DIBAL, LiAlH4, or NaBH4, to obtain the nucleoside compound of formula III'. [ka]

[0154] Non-limiting reagents for lactone reduction include DIBAL-H (diisobutylaluminum hydride), NaBH4, Red-Al (trademark) sodium bis(2-methoxyethoxy)aluminum hydride, and LiAlH4 (lithium aluminum hydride). When the reduction product is a mixture of nucleosides having R-stereochemistry and nucleosides having S-stereochemistry at the hydroxyl group, these compounds can be separated by conventional methods known to those skilled in the art, such as column chromatography or crystallization, to isolate the desired stereochemistry. Alternatively, a mixture of diastereomers can be carried to step (1.2.d) to obtain the compound of formula IV' as a mixture of diastereomers. In this embodiment, the compound of formula IV' (as a mixture of diastereomers at the 1' position) can be reacted with 2-amino-6-chloropurine to obtain the compound of formula V as a mixture of diastereomers. The diastereomer of formula V' can be separated by conventional methods known to those skilled in the art, such as column chromatography or crystallization, to isolate the desired stereochemistry.

[0155] (1.2.d) A step to convert the compound of formula III' into the compound of formula IV'. [ka] (In the formula, X is Cl, Br, or OAc).

[0156] In one embodiment, the hydroxyl group can be converted to Br using PPh3 and CBr4. In another embodiment, the hydroxyl group can be converted to Cl using PPh3 and CCl4. In yet another embodiment, the hydroxyl group can be converted to OAc using ClC(O)CH3 and optionally NEt3.

[0157] (1.2.e) A step to obtain a compound of formula V' by nucleophilic substitution of the compound of formula IV' with 2-amino-6-chloropurine. [ka]

[0158] (1.2.f) 2-amino-6-chloropurine base to 2-amino-N 6 - The process involves converting to a methyl base and deprotecting the 3' and 5' positions to obtain compound 2. [ka]

[0159] In another aspect of the present invention, S other than the specific phosphoramide shown in the diagram of the compound p A method for producing phosphoramide nucleosides is provided. In one embodiment, S p -Isomer R p -A method is provided for producing a phosphoramidate of formula XVI or a pharmaceutically acceptable salt thereof in excess of the isomer: [ka] (In the formula, R 4 is hydrogen, C 1~6 Alkyl (including methyl, ethyl, propyl, and isopropyl), C 3~7 It is a cycloalkyl or aryl (including phenyl and naphthyl), R 5 is hydrogen, or C 1~6 Alkyl (including methyl, ethyl, propyl, and isopropyl), R 6a and R 6b These are, independently, hydrogen and C 1~6 Alkyl (including methyl, ethyl, propyl, and isopropyl), or C 3~7 Selected from cycloalkyl groups, R 7 is hydrogen, C 1~6 Alkyl (including methyl, ethyl, propyl, and isopropyl), C 1~6 Haloalkyl, or C 3~7 (It is cycloalkyl.)

[0160] In one embodiment, diastereomer enriched S of formula XVI p - A method for producing phosphoramidate nucleotides is, (a) Compound 2 is contacted with the dihydrokinine salt of formula XVII in the presence of the specified activators and bases described herein to obtain a diastereomerized S of formula XVI. p - Obtaining phosphoramidate nucleotides, [ka] (b) Diastereomerized S of formula XVI p -Further purification of the phosphoramidate nucleotide to diastereomerically pure S of formula XVI with a diastereomer purity of over 90%, over 95%, or even over 99% p - To obtain purine phosphoramidate nucleotides, (c) Optionally, convert the compound of formula XVI into a pharmaceutically acceptable salt of the compound of formula XVI, Includes, in the formula, R 2 , R 4 , R 5 , R 6a , R 6b , and R 7 This is as defined herein.

[0161] In one embodiment, compounds having alternative amino acid configurations are synthesized by the method discussed above: [ka]

[0162] Similarly, the present invention also provides a method for pharmaceutically acceptable salts of compounds having alternative amino acid configurations, including hemisulfate compounds: [ka]

[0163] definition Compounds are described using their formal names. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which this invention pertains.

[0164] The terms "a" and "an" do not indicate a limit on quantity, but rather indicate the presence of at least one of the items mentioned. The term "or" means "and / or". Unless otherwise specified herein, the enumeration of value ranges is intended simply as a way to refer individually to each distinct value contained within that range, and each distinct value becomes part of this specification by being cited as if they were individually enumerated herein. All endpoints of a range are contained within that range and can be combined independently.

[0165] All methods described herein can be carried out in a preferred order unless otherwise specified herein or clearly rejected by the context. The use of example or illustrative language (e.g., "such as") is intended solely to better illustrate the invention and does not imply any limitation of the scope of the invention unless otherwise asserted.

[0166] Throughout this application, the R / S system of enantiomer nomenclature is followed. Chiral centers relating to the phosphorus atom P are assigned priority according to the Kahn-Ingold-Prelogue priority rule (CIP), where each substituent on atom P is assigned priority based on its atomic number. p or S pIt is named as such. For the CIP rule, refer to "Advanced Organic Chemistry" (2007) by J. March, published by John Wiley & Sons, and IUPAC Rules for the Nomenclature of Organic Chemistry, Section E, Stereochemistry (1974). In the CIP rule, the lowest priority is assigned to the direct substituent with the lowest atomic number on the chiral center P. In the case of phosphoramide, this substituent is N. Next, orient the P center so that the N substituent faces away from the observer. Next, according to the CIP rule, consider the atoms or the next closest atoms (if any) to the three O atoms directly bonded to P. If the atomic numbers of these atoms decrease clockwise, then this enantiomer is R P Let us name it S. When the atomic numbers of these atoms decrease counterclockwise, this enantiomer is S P Let's call it that.

[0167] Symbols present in some of the formulas of the specification and claims [ka] The dashed line indicates that the substituent is oriented downwards on the page. This symbol appears in some of the formulas in the specification and claims. [ka] The wedge-shaped bond indicates that the substituent is oriented upwards on the plane of the paper.

[0168] Compounds prepared by the method of the present invention have one or more stereocenters and may exist, be used, or be isolated in a diastereoisomerically pure form or as a diastereomer-enriched mixture. It should be understood that the method of the present invention can yield a diastereoisomerically pure form or a diastereomer-enriched mixture. It should also be understood that the products of the present invention can be isolated in a diastereoisomerically pure form or as a diastereomer-enriched mixture.

[0169] Unless otherwise specified, a diastereomer mixture may contain two diastereoisomers in any relative ratio.

[0170] As used in this application, "diastereomer-enriched" means that one diastereoisomer is present in excess of the other diastereoisomer.

[0171] "Diastereomerically pure" refers to a compound in which the purity of the diastereoisomer is at least about 90%, about 95%, or even more than about 99%, and which may be 100% pure.

[0172] "Alkyl" refers to a branched or linear saturated aliphatic hydrocarbon group. In one non-limiting embodiment, an alkyl group contains about 1 to about 6 carbon atoms, more commonly 1 to about 4 carbon atoms, or 1 to about 3 carbon atoms. Examples of alkyl groups, but not limited to, include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, n-hexyl, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, and 2,3-dimethylbutane.

[0173] A "cycloalkyl" is a saturated group in a monocyclic or polycyclic (e.g., bicyclic or tricyclic) non-aromatic ring system that contains the entire carbocyclic ring and 3 to 6 carbon atoms ("C3-C6 cycloalkyl"), and does not contain heteroatoms. Non-limiting examples of "cycloalkyl" include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0174] Any compound used in or formed by the methods described herein can be modified to form a "pharmaceutically acceptable salt" under appropriate conditions of use by producing an inorganic acid addition salt or inorganic base addition salt or an organic acid addition salt or organic base addition salt thereof. Salts of the compounds of the present invention can be synthesized from parent compounds having a basic or acidic moiety by conventional chemical methods. Generally, such salts can be prepared by reacting the free acid form of these compounds with a stoichiometric amount of a suitable base (e.g., Na, Ca, Mg, or K hydroxide, carbonate, bicarbonate, etc.) or by reacting the free basic form of these compounds with a stoichiometric amount of a suitable acid. Such reactions are typically carried out in water or an organic solvent, or a mixture of the two. Generally, non-aqueous media such as ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are typical, if feasible. Salts of the compounds of the present invention may optionally be provided in the form of solvates.

[0175] Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic salts of basic residues such as amines, and alkali or organic salts of acidic residues such as carboxylic acids. Pharmaceutically acceptable salts include, for example, conventional salts of parent compounds formed from inorganic or organic acids that are not excessively toxic, and quaternary ammonium salts. For example, conventional salts include salts derived from inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, sulfamic acid, phosphoric acid, and nitric acid, as well as acetic acid, propionic acid, succinic acid, glycolic acid, stearic acid, lactic acid, malic acid, tartaric acid, citric acid, ascorbic acid, pamoic acid, maleic acid, hydroxymaleic acid, phenylacetic acid, glutamic acid, benzoic acid, salicylic acid, mesylic acid, ecylic acid, besylic acid, sulfanilic acid, 2-acetoxybenzoic acid, fumaric acid, toluenesulfonic acid, methanesulfonic acid, ethanedisulfonic acid, oxalic acid, isethionic acid, HOOC-(CH2) n This includes salts prepared from organic acids such as -COOH (where n is 0-4) or using different acids that produce the same counterion. A list of additional suitable salts can be found, for example, in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., p. 1418 (1985).

[0176] C1-C8 alcohols refer to linear / branched and / or cyclic / acyclic alcohols having any number of carbon atoms within that range, and the range is particularly intended to disclose each compound within that range independently. Examples of C1-C8 alcohols, but not limited to, include methanol, ethanol, n-propanol, isopropanol, isobutanol, hexanol, and cyclohexanol.

[0177] C2-C8 ethers refer to linear / branched and / or cyclic / acyclic ethers having any number of carbon atoms within that range, and the range is particularly intended to disclose each compound within that range independently. Examples of C2-C8 ethers, but not limited to, include dimethyl ether, diethyl ether, diisopropyl ether, di-n-butyl ether, methyl-t-butyl ether (MTBE), tetrahydrofuran, and dioxane.

[0178] C3-C7 ketones refer to linear / branched and / or cyclic / acyclic ketones having any number of carbon atoms within that range, and the range is particularly intended to disclose each compound within that range independently. Examples of C3-C7 ketones, but are not limited to, include acetone, methyl ethyl ketone, propanone, butanone, methyl isobutyl ketone, methyl butyl ketone, and cyclohexanone.

[0179] C3-C7 esters refer to linear / branched and / or cyclic / acyclic esters having any number of carbon atoms within that range, and the range is particularly intended to disclose each compound within that range independently. Examples of C3-C7 esters, but not limited to, include ethyl acetate, propyl acetate, and n-butyl acetate.

[0180] C1-C2 chlorocarbons refer to chlorocarbons that have one or two carbon atoms along with any number of chloro atoms to satisfy the desired purpose. Examples of C1-C2 chlorocarbons, but not limited to them, include chloroform, methylene chloride (DCM), carbon tetrachloride, 1,2-dichloroethane, and tetrachloroethane.

[0181] C2-C7 nitriles refer to nitriles having any number of carbon atoms within that range, and the range is particularly intended to disclose each compound within that range independently. Examples of C2-C7 nitriles, but not limited to, include acetonitrile and propionitrile.

[0182] Various solvents refer to, but are not limited to, solvents known to those skilled in the art and used in organic chemistry, and include, diethylene glycol, diglym (diethylene glycol dimethyl ether), 1,2-dimethoxyethane, dimethylformamide, dimethyl sulfoxide, ethylene glycol, glycerin, hexamethylphosphoramide, hexamethylphosphite triamide, N-methyl-2-pyrrolidinone, nitromethane, pyridine, triethylamine, and acetic acid.

[0183] C5~C 12 The term saturated hydrocarbon refers to linear / branched and / or cyclic / acyclic hydrocarbons having any number of carbon atoms within that range, and the range is particularly intended to disclose each compound within that range independently. C5~C 12 Examples of saturated hydrocarbons, though not limited to them, include pentane (including n-pentane), petroleum ether (ligroin), hexane (including n-hexane), heptane (including n-heptane), cyclohexane, and cycloheptane.

[0184] C6~C 12 The term aromatic refers to substituted and unsubstituted hydrocarbons that have a phenyl group in their main chain. Examples of hydrocarbons include benzene, xylene, toluene, chlorobenzene, o-xylene, m-xylene, p-xylene, and xylenes, with toluene being particularly useful.

[0185] Compounds of formulas IIA, IIIA, II', and III' The present invention also provides compounds of formulas IIA, IIIA, II', and III', or pharmaceutically acceptable salts thereof: [ka] (In the formula, R 2a and R 2b It is an oxygen protecting group, and R 2a and R 2b At least one of them is -C(O)OC 1~6Alkyl (e.g., -C(O)OtBu or -C(O)OCH3) or -C(O)O-benzyl, or in an alternative embodiment, R 2a and R 2b At least one of them is -C(O)OC 1~20 Alkyl, -C(O)OC 2~20 Alkenyl, or -C(O)NR 10a R 10b And here, R 10a and R 10b These are, independently, hydrogen and C 1~20 Alkyl, C 2~20 Selected from alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl, where R 2a and R 2b Each of these may be independently optionally substituted with substituents selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl groups, and The bridging structure in equations II' and III' is, [ka] Selected from, The phenyl group in the cross-linked structure may be substituted with substituents selected from alkoxy (but not limited to methoxy and ethoxy), hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl groups).

[0186] In an alternative embodiment, the bridge structure is, [ka] Selected from.

[0187] In one embodiment, the compound of formula IIIA is: [ka] It is a compound of [the compound].

[0188] In one embodiment, the compound of formula IIIA is: [ka] It is a compound of [the compound].

[0189] In one embodiment, the compound of formula III' is: [ka] It is a compound of [the compound].

[0190] In one embodiment, the compound of formula III' is: [ka] It is a compound of [the compound].

[0191] In one embodiment, R 2a and R 2b Both are -C(O)OC 1~6 Alkyl, for example, -C(O)OtBu. In one embodiment, R 2a and R 2b Both are -C(O)O-benzyl. In one embodiment, R 2a is -C(O)OC 1~6 Alkyl or -C(O)O-benzyl, and R 2b This is an oxygen protecting group, which, when bonded to oxygen, is an ester, ether, or silyl ether moiety. In an alternative embodiment, R 2b is -C(O)OC 1~6 Alkyl or -C(O)O-benzyl, and R 2a This is an oxygen protecting group, which, when bonded to oxygen, forms an ester, ether, or silyl ether moiety.

[0192] In an alternative embodiment, R 2a and R 2b Both are -C(O)OCH3. In an alternative embodiment, R 2a is -C(O)OCH3 and R 2bThis is an oxygen protecting group, which, when bonded to oxygen, is an ester, ether, or silyl ether moiety. In an alternative embodiment, R 2b is -C(O)OCH3 and R 2a This is an oxygen protecting group, which, when bonded to oxygen, forms an ester, ether, or silyl ether moiety.

[0193] In an alternative embodiment, R 2a and R 2b At least one of them is -C(O)OC 1~18 Alkyl, -C(O)OC 1~16 Alkyl, -C(O)OC 1~14 Alkyl, -C(O)OC 1~12 Alkyl, -C(O)OC 1~10 Alkyl, -C(O)OC 1~8 Alkyl, -C(O)OC 1~6 Alkyl, -C(O)OC 1~4 Alkyl, -C(O)OC 1~2 Alkyl, -C(O)OC 2~20 Alkyl, -C(O)OC 4~20 Alkyl, -C(O)OC 6~20 Alkyl, -C(O)OC 8~20 Alkyl, -C(O)OC 10~20 Alkyl, -C(O)OC 12~20 Alkyl, -C(O)OC 14~20 Alkyl, -C(O)OC 16~20 Alkyl and -C(O)OC 18~20 Alkyl-containing -C(O)OC 1~20 Selected from alkyl groups. In one embodiment, R 2a and R 2b Both are -C(O)OC 1~20 It is alkyl. In one embodiment, R 2a and R 2b Both are -C(O)OC 16 H 33 That is the case.

[0194] In an alternative embodiment, R 2a and R 2b Both are -C(O)NR10a R 10b , for example, -C(O)NHPh, -C(O)NHBn, -C(O)N(Ph)2, -C(O)N(Bn)2, -C(O)NHC 1~20 Alkyl (not limited to, but including -C(O)NHCH3, -C(O)NHtBu, and -C(O)NHC) 16 H 33 (including), and -C(O)N(C 1~20 Alkyl)2 (not limited to, but including -C(O)N(CH3)2, -C(O)N(tBu)2, and -C(O)N(C 16 H 33 )2 is included). In one embodiment, R 2a and R 2b Both are -C(O)NR 10a R 10b In one embodiment, R 2a is -C(O)NR 10a R 10b And R 2b This is an oxygen protecting group, which, when bonded to oxygen, is an ester, ether, or silyl ether moiety. In an alternative embodiment, R 2b is -C(O)NR 10a R 10b And R 2a This is an oxygen protecting group, which, when bonded to oxygen, forms an ester, ether, or silyl ether moiety.

[0195] In one embodiment, R 2a and R 2b At least one of them is -C(O)NHC 1~18 Alkyl, -C(O)NHC 1~16 Alkyl, -C(O)NHC 1~14 Alkyl, -C(O)NHC 1~12 Alkyl, -C(O)NHC 1~10 Alkyl, -C(O)NHC 1~8 Alkyl, -C(O)NHC 1~6 Alkyl, -C(O)NHC 1~4 Alkyl, -C(O)NHC 1~2 Alkyl, -C(O)NHC 2~20Alkyl, -C(O)NHC 4~20 Alkyl, -C(O)NHC 6~20 Alkyl, -C(O)NHC 8~20 Alkyl, -C(O)NHC 10~20 Alkyl, -C(O)NHC 12~20 Alkyl, -C(O)NHC 14~20 Alkyl, -C(O)NHC 16~20 Alkyl and -C(O)NHC 18~20 -C(O)NHC containing alkyl 1~20 It is alkyl. In one embodiment, R 2a and R 2b Both are -C(O)NHC 1~20 It is alkyl. In one embodiment, R 2a and R 2b Both are -C(O)NHC 16 H 33 That is the case.

[0196] In one embodiment, the protecting group when bonded to oxygen is an ester moiety, for example, a benzoate acetate. In one embodiment, the oxygen protecting group when bonded to oxygen is a silyl ether moiety, for example, trimethylsilyl (TMS), triisopropylsilyl (TIPS), tert-butyldimethylsilyl (TBDMS or TBS), or tert-butyldiphenylsilyl (TBDPS). In one embodiment, the oxygen protecting group when bonded to oxygen is an ether moiety, for example, a methyl ether, a methoxymethyl ether, or a benzyl ether. These protecting groups can be introduced according to one of the procedures for protecting hydroxyls described in Theodora W. Green, Protective Groups in Organic Synthesis, Third Edition, John Wiley & Sons (1999) (which is incorporated herein by reference). For example, when the oxygen protecting group bonded to oxygen is an ester moiety, compounds of formulas II, IIA, III, IIIA, II', or III' can be prepared according to the conditions described on pages 149 to 178 of the document, and when the oxygen protecting group bonded to oxygen is a silyl ether, compounds of formulas II, IIA, III, IIIA, II', or III' can be prepared according to the conditions described on pages 113 to 147 of the document. In one embodiment, the protecting group is a tert-butyldimethylsilyl (TBS) group. The TBS group is selectively introduced into primary alcohols rather than secondary alcohols using the conditions described on page 128 of the document and in Ogilvie et al. Can. J. Chem. 1979, 57, 2230. These conditions include the use of TBSCl, DMAP, and NEt3 in DMF at 25°C.

[0197] Non-limiting examples of additional protecting groups when bonded to oxygen include bromobenzoates, p-methoxybenzyloxymethyl ether (MPBM), o-nitrobenzyloxymethyl ether (NBOM), p-nitrobenzyloxymethyl ether, t-butoxymethyl ether, 2,2,2-trichloroethoxymethyl ether, 3-bromotetrahydropyranyl ether, tetrahydropyranyl ether, tetrahydrothiopyranyl ether, 1-methoxycyclohexyl ether, 1,4-dioxan-2-yl ether, tetrahydrofuranyl ether, tetrahydrothiofuranyl ether, substituted phenyl ethers, 2-picolyl ether, 4-picolyl ether, 1,3-benzodithiolan-2-yl ether, p-chlorophenoxyacetic acid, 3-phenylpropionic acid, p-phenylbenzoic acid, alkyl p-nitrophenylcarbonyl, alkyl benzylcarbonyl, alkyl p-methoxybenzylcarbonyl, alkyl o-nitrobenzylcarbonyl, and alkyl p-nitrobenzylcarbonyl.

[0198] R 2a and R 2b A non-restrictive example of this is: [ka] These are some examples.

[0199] R 2a and R 2b An additional non-limiting example of this is: [ka] These are some examples.

[0200] R 2a and R 2b An additional non-limiting example of this is: [ka] These are some examples.

[0201] R 2aand R 2b An additional non-limiting example of this is: [ka] These are some examples.

[0202] In one embodiment, R 10a is hydrogen. In one embodiment, R 10a It is phenyl.

[0203] In one embodiment, the carbonate compound or carbamate compound of formula IIIA is formula: [ka] It is a compound of [the compound].

[0204] In one embodiment, the carbonate compound or carbamate compound of formula IIIA is formula: [ka] It is a compound of [the compound].

[0205] In one embodiment, the crosslinked compound of formula III' is: [ka] It is a compound of [the compound].

[0206] In one embodiment, the crosslinked compound of formula III' is: [ka] It is a compound of [the compound].

[0207] Non-limiting examples of carbonate or carbamate compounds of formulas IIA and IIIA, or bridged compounds of formulas II' and III', include: [ka] These are some examples.

[0208] Additional non-limiting examples of carbonate compounds of formula IIA include: [ka] These are some examples.

[0209] Additional non-limiting examples of carbonate or carbamate compounds of formulas IIA and IIIA include: [ka] TIFF0007851034000105.tif185170 and TIFF0007851034000106.tif195170 are examples.

[0210] Non-limiting examples of carbonate compounds of formulas IIA and IIIA include: [ka] TIFF0007851034000108.tif208170 is one example.

[0211] Additional non-limiting examples of carbamate compounds of formulas IIA and IIIA include: [ka] TIFF0007851034000110.tif55170 is one example.

[0212] Additional non-limiting examples of carbonate compounds of formulas II' and III' include: [ka] These are some examples.

[0213] Additional non-limiting examples of bridged compounds of formulas II' and III' include: [ka] These are some examples.

[0214] Additional Embodiments 1. In a particular embodiment, the nucleotide of formula XVI is the S of the diastereomer of formula XVI, which has a purity of more than 90%. p - A method for preparing phosphoramidate nucleotides, (a) Contacting nucleoside compound 2 with the dihydrokinine salt of the compound of formula XVII, as well as an activator and a base, to form the diastereomer S of formula XVI. p - The process of obtaining phosphoramidate nucleotides, [ka] (b) Optionally, the diastereomerized S of formula XVI p - A process to further purify phosphoramidate nucleotides to increase their purity, Including, in the formula, R 4 is hydrogen, C 1~6 Alkyl, C 3~7 It is a cycloalkyl or aryl compound. R 5 is hydrogen or C 1~6 It is alkyl, R 6a and R 6b These are, independently, hydrogen and C 1~6 Alkyl and C 3~7 Selected from the group consisting of cycloalkyl, R 7 is hydrogen, C 1~6 Alkyl, C 1~6 Haloalkyl, or C 3~7 A method is provided that involves cycloalkyl. 2.R 4 The method according to Embodiment 1, wherein the aryl is... 3.R 5 The method according to Embodiment 1 or 2, wherein the hydrogen is... 4.R 6a and R 6bThe method according to any one of embodiments 1 to 3, wherein at least one of is hydrogen. 5.R 6a and R 6b The method according to any one of Embodiments 1 to 4, wherein is hydrogen and methyl. 6.R 7 C 1~6 The method according to any one of Embodiments 1 to 5, wherein the alkyl group is used. 7. The activators are HOBt (1-hydroxybenzotriazole), PyBOP (benzotriazole-1-yloxytri(pyrrolidino)phosphonium hexafluorophosphate), HATU (O-(7-azabenzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate), HBTU (3-[bis(dimethylamino)methylumyl]-3H-benzotriazole-1-oxidehexafluorophosphate), HCTU (2 The method according to any one of Embodiments 1 to 6, selected from (6-chloro-1H-benzotriazol-1-yl)-1,1,3,3-tetramethylaminium hexafluorophosphate), COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate), and TBTU (O-benzotriazol-1-yl-1,1,3,3-tetramethyluronium tetrafluoroborate). 8. The method according to any one of Embodiments 1 to 7, wherein the activator is HATU(O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate). 9. The method according to any one of Embodiments 1 to 7, wherein the activator is COMU((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate). 10. The method according to any one of Embodiments 1 to 9, wherein the base is NR3, and R can be independently selected from H, alkyl, aryl, heteroaryl, alkenyl, alkynyl, benzyl, and allyl, where at least one R is not hydrogen. 11. The method according to any one of Embodiments 1 to 10, wherein the base is DIPEA (N,N-diisopropylethylamine) or NEt3 (triethylamine). 12. The method according to any one of Embodiments 1 to 11, wherein the base is DIPEA (N,N-diisopropylethylamine). 13. The method according to any one of Embodiments 1 to 9, wherein the base is a kinin. 14. The method according to any one of Embodiments 1 to 13, wherein step (a) is carried out in a polar aprotic solvent. 15. The method according to Embodiment 13, wherein the solvent is selected from dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate (ԅ), acetonitrile (MeCN), dimethyl sulfoxide (DMSO), acetone, and N-methylpyrrolidone. 16. The method according to any one of Embodiments 1 to 13, wherein step (a) is carried out in a mixture of solvents selected from dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate (SiO), acetonitrile (MeCN), dimethyl sulfoxide (DMSO), acetone, and N-methylpyrrolidone. 17. The method according to Embodiment 16, wherein the solvent mixture comprises dichloromethane (DCM) and 2-methyltetrahydrofuran (2-MeTHF). 18. S before step (b) p Diastereomer:R p The method according to any one of Embodiments 1 to 17, wherein the ratio of diastereomers is approximately 60:40. 19. S before step (b) p Diastereomer:R p The method according to any one of Embodiments 1 to 18, wherein the ratio of diastereomers is approximately 70:30. 20. S before process (b) p Diastereomer:R pThe method according to any one of Embodiments 1 to 19, wherein the ratio of diastereomers is approximately 80:20. 21. S before process (b) p Diastereomer:R p The method according to any one of Embodiments 1 to 20, wherein the diastereomer ratio is approximately 90:10. 22. The method according to any one of Embodiments 1 to 21, wherein the nucleotide of formula XVI has a purity of more than approximately 98%. 23. The method according to any one of Embodiments 1 to 22, wherein the nucleotide of formula XVI has a purity of more than approximately 99%. 24. The purification in step (b) is selective crystallization, according to any one of Embodiments 1 to 23. 25. The method according to Embodiment 24, wherein the crystallization is carried out in a polar organic solvent. 26. The method according to Embodiment 24 or 25, wherein the crystallization is carried out in an alkyl ester. 27. The method according to any one of Embodiments 24 to 26, wherein the crystallization is carried out in ethyl acetate or isopropyl acetate. 28. The method according to Embodiment 24, wherein the crystallization is carried out in a mixture of solvents. 29. The method according to Embodiment 24 or 28, wherein the crystallization is carried out in a mixture of a polar organic solvent and an aromatic solvent. 30. The method according to any one of Embodiments 24, 28, or 29, wherein the crystallization is carried out in a mixture of ethyl acetate and toluene. 31. (c) The method according to any one of Embodiments 1 to 30, further comprising the step of converting the compound of formula XVI into a pharmaceutically acceptable salt. 32. The method according to Embodiment 31, wherein the pharmaceutically acceptable salt is a hemisulfate. 33. The compound of formula XVI is [ka] The compound having the structure of formula XVII is [ka] The method according to any one of embodiments 1 to 32, having the structure described herein. 34. In a particular embodiment, a method for preparing compound 2, (a) A step of protecting (3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)-3-methyldihydrofuran-2(3H)-one with 5'-hydroxyl and 3'-hydroxyl to obtain the compound of formula I, [ka] (b) A step of converting the compound of formula I into the compound of formula II, [ka] (c) A step of reducing the compound of formula II to obtain the compound of formula III, [ka] (d) A step of converting the compound of formula III into the compound of formula IV, [ka] (e) A step of converting the compound of formula IV to the compound of formula V via nucleophilic substitution using 2-amino-6-chloropurine, [ka] (f) A step of converting the compound of formula V into compound 2, [ka] Including, in the formula, R 1a and R 1b It is an oxygen protecting group, R 1a and R 1b At least one of them is -C(O)OC 1~6The group is alkyl, -C(O)O-benzyl, or -CH2-phenyl, where the phenyl group is substituted with at least one substituent selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl. R 1a and R 1b At least one of them is -C(O)OC 1~20 Alkyl, -C(O)OC 2~20 Alkenyl, or -C(O)NR 10a R 10b And, R 10a and R 10b These are, independently, hydrogen and C 1~20 Alkyl, C 2~20 Selected from alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl, where C 1~20 Alkyl, C 2~20 Alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl may optionally be substituted with one, two, three, or four substituents independently selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl, and A method is provided in which X is Cl, Br, or OAc. 35. The method according to embodiment 34, wherein X is Br. 36.R 1a and R 1b The method according to embodiment 34 or 35, wherein is -C(O)OtBu. 37. A method for preparing compound 2 in a particular embodiment, (a) A step of protecting (3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)-3-methyldihydrofuran-2(3H)-one with 5'-hydroxyl and 3'-hydroxyl to form a crosslinking structure and obtain the compound of formula I', [ka] (b) A step of converting the compound of formula I' into the compound of formula II', [ka] (c) A step of reducing the compound of formula II' to obtain the compound of formula III', [ka] (d) A step of converting the compound of formula III' into the compound of formula IV', [ka] (e) A step of converting the compound of formula IV' to the compound of formula V' via nucleophilic substitution using 2-amino-6-chloropurine, [ka] (f) A step of converting the compound of formula V' into compound 2, [ka] Including, in the formula, The aforementioned bridge structure is, [ka] Selected from, and, A method is provided in which X is Cl, Br, or OAc. 38. The method according to any one of embodiments 34 to 37, wherein step (b) is carried out using a fluorinating agent selected from sulfonyl fluoride / TREAT·HF mixture (SO2F2, NET3·3HF), DAST (Et2NSF3), and morpholinosulfur trifluoride (Morph-DAST). 39. The method according to any one of Embodiments 34 to 38, wherein step (c) is carried out using a reducing agent selected from DIBAL-H (diisobutylaluminum hydride), NaBH4, Red-Al (trademark) (sodium bis(2-methoxyethoxy)aluminum hydride), and LiAlH4 (lithium aluminum hydride). 40. The method according to any one of embodiments 34 to 39, wherein step (d) is carried out using triphenylphosphine and dibromohydantoin. 41. The method according to any one of Embodiments 34 to 40, wherein step (e) is carried out using a non-nucleophilic base selected from sodium tert-butoxide, potassium tert-butoxide, sodium tert-pentoxide, potassium tert-pentoxide, lithium diisopropylamide, and lithium bis(trimethylsilyl)amide. 42. Step (f) is, (f.1) A step of reacting the compound of formula V or formula V' with methylamine (NH2Me) to obtain a crude mixture, (f.2) A step of reacting the crude mixture from step (f.1) under deprotection conditions to obtain compound 2, The method according to any one of embodiments 34 to 41, further comprising the above. 43. The method according to Embodiment 42, wherein the deprotection conditions are DBU and methanol. 44. In a particular embodiment, a method for preparing a compound of formula VII, (a) A step of converting the compound of formula V into the compound of formula VI, [ka] (b) The compound of formula VI is reacted with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of an activator and a base, and S p - diastereomer is R p - Protected diastereomers that are present in excess of the diastereomers, enriched by formula VII S p - The process of obtaining phosphoramidate nucleotides, [ka] Including, in the formula, R 1a and R 1b It is an oxygen protecting group, R 1a and R 1bAt least one of them is -C(O)OC 1~6 The group is alkyl, -C(O)O-benzyl, or -CH2-phenyl, where the phenyl group is substituted with at least one substituent selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl. R 1a and R 1b At least one of them is -C(O)OC 1~20 Alkyl, -C(O)OC 2~20 Alkenyl, or -C(O)NR 10a R 10b And, R 10a and R 10b These are, independently, hydrogen and C 1~20 Alkyl, C 2~20 Selected from alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl, where C 1~20 Alkyl, C 2~20 A method is provided in which the alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl may optionally be substituted with at least one substituent selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl. 45. The method according to Embodiment 44, wherein step (a) is performed in a single conversion using methylamine. 46. ​​The method according to Embodiment 44 or 45, wherein the activator in step (b) is HATU (O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) or COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate). 47. The method according to any one of Embodiments 44 to 46, wherein the base in step (b) is DIPEA (diisopropylethylamine). 48. (c) Further comprising the step of converting the compound of formula VII into compound 1, [ka] The method according to any one of embodiments 44 to 47. 49. The method according to Embodiment 48, wherein step (c) is performed using DBU in methanol. 50. In a particular embodiment, the compound of formula VIII is reacted with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate using an activator and a base, S p - diastereomer is R p - Protected diastereomer enriched in excess of diastereomers of formula IX p - A method for preparing the compound of formula IX by obtaining phosphoramidate nucleotides: [ka] (In the formula, R 3a The following are provided: selected from tert-butoxycarbonyl-(Boc), benzyloxycarbonyl-(Cbz), benzyl, and p-methoxybenzyl. 51. The compound of formula VIII above, (a) Compound V of formula N 2 A step of protecting the compound of formula X at a certain position, [ka] (b) A step of converting the compound of formula X to the compound of formula VIII, [ka] The method according to Embodiment 50, further comprising preparing by a method comprising: 52. The method according to Embodiment 51, wherein step (b) is performed in a single conversion using methylamine (NH2Me). 53. Further comprising converting the compound of formula IX into compound 1, [ka] The method according to any one of embodiments 50 to 52. 54. The method according to Embodiment 53, wherein the compound of formula IX is converted to compound 1 by reacting it with Pd / C and hydrogen. 55. The method according to Embodiment 53, wherein the compound of formula IX is converted to compound 1 by reacting it with HCl in DCM. 56. The method according to any one of Embodiments 50 to 55, wherein the activator is HATU (O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) or COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate). 57. The method according to any one of embodiments 50 to 56, wherein the base is DIPEA (diisopropylethylamine). 58. In a particular embodiment, the compound of formula XI is reacted with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate using an activator and a base, S p - diastereomer is R p - Protected diastereomers that are present in excess of the diastereomers, enriched by formula XII S p - A method for preparing the compound of formula XII by obtaining phosphoramidate nucleotides: [ka] (In the formula, R 3a and R 3b The following are independently provided (selected from tert-butoxycarbonyl-(Boc), benzyloxycarbonyl-(Cbz), benzyl, and p-methoxybenzyl). 59. Further comprising converting the compound of formula VIII to the compound of formula XI, [ka] The method described in Embodiment 58. 60. Further comprising converting the compound of formula XII into compound 1, [ka] The method described in Embodiment 58 or 59. 61. The method according to Embodiment 60, wherein the compound of formula XII is converted to compound 1 using HCl in DCM. 62. The method according to Embodiment 60, wherein the compound of formula XII is converted to compound 1 using Pd / C and hydrogen. 63. The method according to Embodiment 60, wherein the compound of formula XII is converted to compound 1 using DBU and MeOH. 64. The method according to any one of Embodiments 58 to 63, wherein the activator is HATU (O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) or COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate). 65. The method according to any one of embodiments 58 to 64, wherein the base is DIPEA (diisopropylethylamine). 66. In a particular embodiment, the compound of formula XIII is reacted with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate using an activator and a base, S p - diastereomer is R p - Protected diastereomer enriched in excess of diastereomers of formula XIV p - A method for preparing the compound of formula XIV by obtaining phosphoramidate nucleotides: [ka] (In the formula, R 3a and R 3b The following are independently provided (selected from tert-butoxycarbonyl-(Boc), benzyloxycarbonyl-(Cbz), benzyl, and p-methoxybenzyl). 67. Further comprising converting compound 2 to the compound of formula XIII, [ka] The method according to embodiment 66. 68. Further comprising converting the compound of formula XIV into compound 1, [ka] The method according to embodiment 66 or 67. 69. The method according to embodiment 68, wherein the compound of formula XIV is converted to compound 1 using HCl in DCM. 70. The method according to Embodiment 68, wherein the compound of formula XIV is converted to compound 1 using Pd / C and hydrogen. 71. The method according to Embodiment 68, wherein the compound of formula XIV is converted to compound 1 using DBU and MeOH. 72. The method according to any one of Embodiments 66 to 71, wherein the activator is HATU (O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) or COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate). 73. The method according to any one of embodiments 66 to 72, wherein the base is DIPEA (diisopropylethylamine). 74. In a particular embodiment, formula XVII: [ka] A method for preparing the compound, (a) A step of coupling a appropriately substituted dichlorophosphate ester with benzyl alcohol to produce an appropriately substituted benzyl phosphorochloride without isolation, and subsequently reacting the substituted benzyl phosphorochloride with an appropriately substituted amino acid to obtain a benzyl phosphoramidate, [ka] (b) The benzyl phosphoramidate is debenzylated in the presence of a chiral tertiary amine selected from quinine and dihydroquinine to obtain a compound of formula XVII, [ka] Including, in the formula, R 4 is hydrogen, C 1~6 Alkyl, C 3~7 It is a cycloalkyl or aryl compound. R 5 is hydrogen or C 1~6 It is alkyl, R 6a and R 6b These are, independently, hydrogen and C 1~6 Alkyl, or C 3~7 Selected from cycloalkyl, R 7 is hydrogen, C 1~6 Alkyl, C 1~6 Haloalkyl, or C 3~7 A method is provided that involves cycloalkyl. 75.R 4 The method according to embodiment 74, wherein the aryl is... 76.R 4 The method according to Embodiment 74 or 75, wherein is phenyl. 77.R 5 The method according to any one of embodiments 74 to 76, wherein the hydrogen is... 78.R 6a and R 6b The method according to any one of embodiments 74 to 77, wherein at least one of is hydrogen. 79.R 6a and R 6b The method according to any one of embodiments 74 to 78, wherein is hydrogen and methyl. 80.R 7 C 1~6 The method according to any one of embodiments 74 to 79, wherein the alkyl group is used. 81.R 7The method according to any one of embodiments 74 to 80, wherein isopropyl. 82. Step (b) is the method according to any one of embodiments 74 to 81, performed using Pd / C and hydrogen. 83. The method according to any one of embodiments 74 to 82, wherein dihydroquinine is used in step (b). 84. In certain embodiments, compounds of formula IIA, formula IIIA, formula II', or formula III', or pharmaceutically acceptable salts thereof: [ka] (In the formula, R 2a and R 2b It is an oxygen protecting group, R 2a and R 2b At least one of them is -C(O)OC 1~20 Alkyl, -C(O)OC 2~20 Alkenyl, or -C(O)NR 10a R 10b And, R 10a and R 10b These are, independently, hydrogen and C 1~20 Alkyl, C 2~20 Selected from alkenyl, aryl, arylalkyl, heteroaryl, and heteroarylalkyl, R 2a and R 2b Each of these may be independently optionally substituted with substituents selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl groups, and The aforementioned bridge structure is, [ka] Selected from, These are provided (which are optionally substituted with substituents selected from alkoxy, hydroxy, nitro, bromo, chloro, fluoro, azide, and haloalkyl). 85.R 2a and R 2bThe compound described in Embodiment 84 is -C(O)OtBu. 86.R 2a and R 2b The compound described in Embodiment 84 is -C(O)OMe. 87. In a particular embodiment, formula XVII: [ka] (In the formula, R 4 is hydrogen, C 1~6 Alkyl, C 3~7 It is a cycloalkyl or aryl compound. R 5 is hydrogen or C 1~6 It is alkyl, R 6a and R 6b These are, independently, hydrogen and C 1~6 Alkyl, or C 3~7 Selected from cycloalkyl, R 7 is hydrogen, C 1~6 Alkyl, C 1~6 Haloalkyl, or C 3~7 Compounds (which are cycloalkyl) are provided. 88.R 4 The compound according to embodiment 87, wherein the compound is an aryl compound. 89.R 4 The compound according to embodiment 87 or 88, wherein the compound is phenyl. 90.R 5 The compound is hydrogen, as described in any one of embodiments 87 to 89. 91.R 6a and R 6b A compound according to any one of embodiments 87 to 90, wherein at least one of the elements is hydrogen. 92.R 6a and R 6b The compound according to any one of embodiments 87 to 91, wherein the compounds are hydrogen and methyl. 93.R 7 C 1~6 A compound according to any one of embodiments 87 to 92, wherein the compound is alkyl. 94.R 7 The compound is isopropyl, as described in any one of embodiments 87 to 93. 95. Structure: [ka] A compound according to any one of embodiments 87 to 94. 96. In a particular embodiment, the structure: [ka] The compound is provided. 97. In a particular embodiment, the structure: [ka] The compound is provided.

[0215] Coupling of the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate with nucleoside compound 2: In one embodiment of the present invention, a diastereomer of compound 1, pure S p -Methods for synthesizing phosphoramidate nucleotides are, (a) Contacting nucleoside compound 2 with the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate in the presence of the specified activator and base described herein, S p - diastereomer is R p - Diastereomer-enriched S, which is substantially in excess of diastereomers. p - A step to obtain phosphoramidate nucleotide compound 1, [ka] (b) Optionally, diastereomer-enriched S p -Phosphoramide nucleotide compound 1 is further purified, for example by selective crystallization, to obtain diastereomerally pure S with a diastereomer purity of over 90%, or even over 95%, or even over 99%.p - The process of obtaining compound 1, Includes.

[0216] In one embodiment, the activator is COMU((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate).

[0217] In one embodiment, the activator is HATU(O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate).

[0218] In some embodiments, alternative activators, typically but not limited to, benzotriazole-based activators including HOBt (1-hydroxybenzotriazole), PyBOP (benzotriazole-1-yloxytri(pyrrolidino)phosphonium hexafluorophosphate), HBTU (3-[bis(dimethylamino)methylumyl]-3H-benzotriazole-1-oxidehexafluorophosphate), HCTU (2-(6-chloro-1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium hexafluorophosphate), and TBTU (O-benzotriazole-1-yl-1,1,3,3-tetramethyluronium tetrafluoroborate).

[0219] Non-limiting examples of additional alternative activators include AOMP (5-(7-azabenzotriazole-1-yloxy)-3,4-dihydro-1-methyl2H-pyrrolium hexachloroantimonate), AOP ((7-azabenzotriazole-1-yl)oxytris(dimethylamino)phosphonium hexafluorophosphate), BDDC (bis(4-(2,2-dimethyl-1,3-dioxolyl)-methyl-carbodiimide), BD MP (5-(1H-benzotriazole-1-yloxy)-3,4-dihydro-1-methyl2H-pyrrolium hexachloroantimonate), BDP (benzotriazole-1-yldiethyl phosphate), BEC (N-tert-butyl-N'-ethylcarbodiimide), BEMT (2-bromo-3-ethyl-4-methylthiazolium tetrafluoroborate), BEP (2-bromo-1-ethylpyridinium tetrafluoroborate) BEPH (2-bromo-1-ethylpyridinium hexachloroantimonate), BMP-Cl (N,N'-bismorpholinophosphinate), Boc (t-butyloxycarbonyl), BOMP (2-(benzotriazole-1-yloxy)-1,3-dimethyl-2-pyrrolidine-1-yl-1,3,2-diazaphosphoridinium hexafluorophosphate), BOP (benzotriazole-1-yloxytris(dimethylamine) (N)Phosphonium hexafluorophosphate), BOP-Cl(N,N'-bis(2-oxo-3-oxazolidinyl)phosphinate), BroP(bromotris(dimethylamino)phosphonium hexafluorophosphate), Bsmoc(1,1-dioxobenzo-bthiophen-2-ylmethyloxycarbonyl), Bspoc(2-(tert-butylsulfonyl)-2-propyloxycarbonyl), Bts-Fmoc(2,7-Bis(trimethylsilyl)-9-Fluorenylmethyloxycarbonyl), BTFFH (Bis(tetramethylene)fluoroformamidinium hexafluorophosphate), BPMP (1-(1H-benzotriazole-1-yloxy)phenylmethylenepyrrolidinium hexachloroantimonate), BTC (Triphosgene), BTCFH (Bis(tetramethylene)chloroformamidinium hexafluorophosphate, (PyClU)), Bts-Cl (Benzothiazole- 2-Sulfonyl chloride), Cbz, Z (benzyloxycarbonyl), CDMT (2-chloro-4,6-dimethoxy-1,3,5-triazine), CC (cyanuryl chloride), CDPOP (pentachlorophenyldiphenyl phosphate), CDPP (pentachlorophenyldiphenyl phosphinate), CF (cyanuryl fluoride), CF3-BOP ([6-(trifluoromethyl)benzotriazole-1-yl)-N-oxytris(dimethylamino)phosphonium hexafluorophosphate) CF3-HBTU(2-6-(trifluoromethyl)benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate), CF3-NO2-PyBOP(4-nitro-6-(trifluoromethyl)benzotriazol-1-yl)-oxytris(pyrrolidino)), 6-Cl-HOBI(6-chloro-N-hydroxy-2-phenylbenzimidazolephosphonium hexafluorophosphate), CF3-PyBOP(6-(trifluoro (Isopropyl chloro-1,)(3-dimethyl-1H-benzimidazolium hexafluorophosphate), CMPI (2-chloro-1-methylpyridinium iodide), COMU (1-(1-(cyano-2-ethoxy-2-oxoethylideneaminooxy)-dimethylaminomorpholinomethylene)methanaminonium hexafluorophosphate), Cpt-Cl (1-oxochlorophosphorane), CPC (N,N'-dicyclopentylcarbodiimide), CPP (2-chloro-1,3-dimethylpyrimidinium hexafluorophosphate), DCC (N,N'-dicyclo Hexylcarbodiimide), DCMT (2,4-dichloro-6-methoxy-1,3,5-triazine), DECP (diethylcyanophosphonate), DEPAT (3-(diethoxyphosphoryloxy)-1,2,3-pyridino-βtriazine-4-(3H)-one), DKP (2,5-diketopiperazine), DEBP (diethyl 2-(3-oxo-2,3-dihydro-1,2-benzisosulfonazolyl)phosphonate), DEPB (diethylphosphorobromide), DEPBO (N-diethoxyphosphorylbenzoxazolone), DEP BT(3-(diethoxyphosphoryloxy)-1,2,3-benzotriazine-4(3H)-one), DEPC (diphenyl phosphorochloride), DEFFH (1,2-diethyl-3,3-tetramethylenefluoroformamidinium hexafluorophosphate), DFIH (1,3-dimethyl-2-fluoro-4,5-dihydro-1H-imidazolium hexafluorophosphate), DIC (N,N'-diisopropylcarbodiimide), DMCH (N-(chloro(morpholino)methylene)-N-methylmethanaminonium hexafluorophosphate) (Luolophosphate), DMCT (2-chloro-4,6-dimethyl-1,3,5-triazine), DMFFH (1,2-dimethyl-3,3-tetramethylenefluoroformamidinium hexafluorophosphate), DMFH (N-(fluoro(morpholino)methylene)-N-methylmethanaminonium hexafluorophosphate), DMTMM (4-(4,6-dimethoxy[1,3,5]triazine-2-yl)-4-methylmorpholinium chloride), DNAs (3H-[1,2,3]triazolo[4,5-b]pyridine-3-yl 2,4-Dinitrobenzenesulfonate), DNBs (1H-benzo[d][1,2,3]triazole-1-yl2,4-dinitrobenzenesulfonate), DOMP (5-(30,40-dihydro-40-oxo-10,20,30-benzotriazine-30-yloxy)-3,4-dihydro-1-methyl-2H-pyrrolium hexachloroantimonate), DOPBO (N-(2-oxo-1,3,2-dioxaphosphorinanyl)-benzooxy Sazolone), DOPBT (3-[O-(2-oxo-1,3,2-dioxaphospholinanyl)-oxy]-1,2,3-benzotriazine-4(3H)-one), DOEPBI (diethyl phosphate 2-phenylbenzimidazole-1-yl ester), DOPPBI (diphenyl-2-phenylbenzimidazole-1-yl phosphate), DPPBI (diphenylphosphinate 2-phenylbenzimidazole-1-yl ester), DPPAT (3-(diphenoxyphosphoryloxy)-1,2,3-pyridino-β-triazine-4-(3H)-one), DPP-Cl (diphenylphosphinate), DPPA (diphenylphosphoryl azide), Dtb-Fmoc (2,7-di-tert-butyl-9-fluorenylmethyloxycarbonyl), EDC (1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide hydrochloride), FDMP (3,5-bis(trifluoro Methylphenyl (phenyl diphenyl phosphinate), FDPP (pentafluorophenyl diphenyl phosphinate), FEP (2-fluoro-1-ethylpyridinium tetrafluoroborate), FEPH (2-fluoro-1-ethylpyridinium hexachloroantimonate), FIP (2-fluoro-1,3-dimethylimidazolidinium hexafluorophosphate), Fmoc (9-fluorenylmethyloxycarbonyl), FOMP 2H-Pyrrolium(5-(pentafluorophenyloxy)-3,4-dihydro-1-methyl-hexachloroantimonate), HAE2PipU(O-(1H-1,2,3-triazolo[4,5-b]pyridine-1-yl)-1,1-diethyl-3,3-pentamethyleneuronium), HAE2PyU(O-(1H-1,2,3-triazolo[4,5-b]pyridine-1-yl)-1,1-diethyl-3,3-tetramethyleneuronium hexafluorophosphate), HAM2PipU(O-(1H-1,2,3-triazolo[4,5-b]pyridine-1-yl)-1,1-dimethyl-3,3-pentamethyleneuronium hexafluorophosphate), HAM2PyU(O-(1H-1,2,3-triazolo[4,5-b]pyridine-1-yl)-1,1-dimethyl-3,3-tetramethyleneuronium hexafluorophosphate), HAMTU(O-(7-azabenzotriazol-1-yl)-1,3-dimethyl-1,3 -Trimethyleneuronium hexafluorophosphate), HAMDU (O-(7-azabenzotriazol-1-yl)-1,3-dimethyl-1,3-dimethyluronium hexafluorophosphate), HAPipU (O-(7-azabenzotriazol-1-yl)-1,1,3,3-bis(pentamethylene)uronium hexafluorophosphate), HAPyU (1-(1-pyrrolidinyl-1H-1,2,3-triazolo[4,5-b]-pyridine-1-ylmethylene)pyrrolidinium hexafluorophosphate N -Oxide), HAPyTU (1-(1-pyrrolidinyl-1H-1,2,3-triazolo[4,5-b]-pyridine-1-ylmethylene)pyrrolidinium hexafluorophosphate N-sulfide), HAPTU (7-azabenzotriazol-1-yl)-1,1,3-trimethyl-1-phenyluronium hexafluorophosphate), HATTU (S-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate), HATU (O-(1H-1,2,3-tri Azolo[4,5-b]pyridine-1-yl)-1,1,3,3-tetraethyluronium hexafluorophosphate), HBE2PipU(O-(1H-benzotriazol-1-yl)-1,1-diethyl-3,3-pentamethyleneuronium hexafluorophosphate), HBE2PyU(O-(1H-benzotriazol-1-yl)-1,1-diethyl-3,3-tetramethyleneuronium hexafluorophosphate), HBM2PipU(O-(1H-benzotriazol-1-yl)-1,1-dimethyl-3,3-Pentamethyleneuronium hexafluorophosphate), HBM2PyU(O-(1H-benzotriazol-1-yl)-1,1-dimethyl-3,3-tetramethyleneuronium hexafluorophosphate), HBMTU(O-(benzotriazol-1-yl)-1,3-dimethyl-1,3-trimethyleneuronium hexafluorophosphate), HBPTU((7-benzotriazol-yl)-1,1,3-trimethyl-1-phenyluronium hexafluorophosphate), HBTeU(O-(1H- (Benzotriazol-1-yl)-1,1,3,3-tetraethyluronium hexafluorophosphate), HBMDU (O-(benzotriazol-1-yl))-1,3-dimethyl-1,3-dimethyluronium hexafluorophosphate), HBPipU (O-(benzotriazol-1-yl)-1,1,3,3-bis(pentamethylene)uronium hexafluorophosphate), HBPyU (O-(benzotriazol-1-yl)oxybis(pyrrolidino)-uronium hexafluorophosphate), HDATU (O-(3,4-dihydro-4-oxo-5-azabenzo-1,2,3-triazine-3-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate), HDAPyU (O-(3,4-dihydro-4-oxo-5-azabenzo-1,2,3-triazine-3-yl)-1,1,3,3-bis(tetramethylene)uronium hexafluorophosphate), HDTU (O-(3,4-dihydro-4-oxo-1,2,3-benzotriazine-3-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) (T), HDATU(O-(3,4-dihydro-4-oxo-5-azabenzo-1,2,3-triazine-3-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate), HDA(1-((dimethylamino)-(morpholino)methylene)-1H-[1,2,3]triazolo[4,5-b]pyridinium hexafluorophosphate-3-oxide), 4-HDMA(3-((dimethylamino)-(morpholino)methylene)-1H-[1,2,3]triazolo[4,5-b]pyridinium hexafluorophosphate-1-oxide) ), HDMB (1-((dimethylamino)(morpholino)methylene)-1H-benzotriazolium hexafluorophosphate-3-oxide), HDMC (6-chloro-1-((dimethylamino)(morpholino)methylene)-1H-benzotriazolium hexafluorophosphate-3-oxide), 6-6-HDMFB (6-trifluoromethyl-1-((dimethylamino)(morpholino)methylene)-1H-benzotriazolium hexafluorophosphate-3-oxide), HDMODC (1-[(1-(dicyanomethyleneaminooxy )-dimethylaminomorpholinomethylene)]methanaminonium hexafluorophosphate), HDMODeC(1-[(1,3-diethoxy-1,3-dioxopropane-2-ylideneaminooxy)-dimethylaminomorpholinomethylene)]methanaminonium hexafluorophosphate), HDMOPC(N-[(cyano(pyridine-2-yl)methyleneaminooxy)-(dimethylamino)methylene]-N-morpholinometanaminonium hexafluorophosphate), HDMP(1-((dimethylamino)(morpholino))oxypyrrolidine-2,5-Dionemethanaminonium hexafluorophosphate), HDMPfp(1-((dimethylamino)-(morpholino))oxypentafluorophenylmethanaminonium hexafluorophosphate), HDmPyODC(1-[(1-(cyano-2-ethoxy-2-oxoethylideneaminooxy)-dimethylaminopyrrolodinomethylene)]methanaminonium hexafluorophosphate), HDPyU(O-(3,4-dihydro-4-oxo-1,2,3-benzotriazine-3-yl)-1,1,3,3-bis(tetramethylene)uro HDTMA (1-((dimethylamino)(thiomorpholino)methylene)-1H-[1,2,3]triazolo[4,5-b]pyridinium hexafluorophosphate-3-oxide), HDTMB (1-((dimethylamino)(thiomorpholino)methylene)-1H-benzotriazolium hexafluorophosphate-3-oxide), HDmPyODeC (1-[(1,3-diethoxy-1,3-dioxopropane-2-ylideneaminooxy)-dimethylaminopyrrolodinomethylene)]methanami HMPyOC(1-(1-(cyano-2-ethoxy-2-oxoethylideneaminooxy)-dimethylamino-pyrrolodinomethylene)]methanaminonium hexafluorophosphate), HMPyODC(1-((dicyanomethyleneaminooxy)morpholinomethylene)pyrrolidinium hexafluorophosphate), HMPA(hexamethylphosphoramide), HMPyOC(1-((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)(morpholino)methylene)pyrrolidinium Hexafluorophosphate), HOAt (1-hydroxy-7-azabenzotriazole), 4-HOAt (4-aza-1-hydroxybenzotriazole), 5-HOAt (5-aza-1-hydroxybenzotriazole), 6-HOAt (6-aza-1-hydroxybenzotriazole), HOBI (N-hydroxy-2-phenylbenzimidazole), HOCt (ethyl-1-hydroxy-1H-1,2,3-triazole-4-carboxylate), HODhbt (3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine), HODhad (3-hydroxy-4-oxo-3,4-dihydro-5-azabenzo-1,3-diazene), HODhat (3-hydroxy-4-oxo-3,4-dihydro-5-azabenzo-1,2,3-triazene), HODT (S-(1-oxide-2-pyridinyl)-1,3-dimethyl-1,3-trimethylenethionium hexafluorophosphate), HOSu (N-hydroxysuccinimide), HOI (N-hydroxyindorin-2-one), 6-NO2-HOBt (1-hydroxy (Loxy-6-nitrobenzotriazole), HONP (p-nitrophenyl active ester), HOPy (1-hydroxy-2-pyridinone), 6-CF3-HOBt (6-trifluoromethyl-1-hydroxybenzotriazole), PS-SO2-HOBt (polymer-supported 1-hydroxy-6-disulfoxide benzotriazole), PS-HOSu (polymer-supported N-hydroxysuccinimide), PS-DCT (polymer-supported 2,4-dichloro-1,3,5-triazine), HONB (N-hydroxy-5-norbol). Nen-endo-2,3-dicarboximide), HOTT(S-(1-oxide-2-pyridinyl)-1,1,3,3-tetramethylthiouronium hexafluorophosphate), HOTU(O-[cyano(ethoxycarbonyl)methyleneamino]-N,N,N',N'-tetramethyluronium hexafluorophosphate), HPyOPfp(N,N,N',N'-bis(tetramethylene)-O-pentafluorophenyluronium hexafluorophosphate), HPFTU(N,N,N',N'-bis(tetramethylene) HPTU(2-(2-oxo-1(2H)-pyridyl-1,1,3,3-tetramethyluronium hexafluorophosphate), HPyONP(N,N,N',N'-bis(tetramethylene)-O-2-nitrophenyluronium hexafluorophosphate), HPyOTCp(N,N,N',N'-bis(tetramethylene)-O-pentafluorophenyluronium hexafluorophosphate), HPySPfp(N,N,N',N'-Bis(tetramethylene)-S-pentafluorothiophenyluronium hexafluorophosphate), HSTU(2-succinimide-1,1,3,3-tetramethyluronium hexafluorophosphate), HTODC(O-[(dicyanomethylidene)-amino]-1,1,3,3-tetramethyluronium hexafluorophosphate), HTODeC(O-[(diethoxycarbonylmethylidene)amino]-1,1,3,3-tetramethyluronium (Umium hexafluorophosphate), HTOPC (N-[(cyano(pyridine-2-yl)methyleneaminooxy)-(dimethylamino)methylene)-N-methylmethanaminonium hexafluorophosphate), MPTA (methylmethanaminonium tetrafluoro), MPTO (3-dimethylphosphinothio-2(3H)-oxazolone), Mspoc (2-methylsulfonyl-3-phenyl-1-propa-2-enyloxycarbonyl), Mukaiyama Reagent (2-chloro -1-methylpyridinium iodide), NAs(3-((naphthalene-2-ylsulfonyl)methyl)-3H-[1,2,3]-triazolo[4,5-b]pyridine), 2-NAs(3H-[1,2,3]triazolo[4,5-b]pyridine-3-yl2-nitrobenzenesulfonate), 4-NAs(3H-[1,2,3]triazolo[4,5-b]pyridine-3-yl4-nitrobenzenesulfonate), NBs(1-((naphthalene-2-ylsulfonyl) Methyl)-1H-benzo-[d][1,2,3]triazole), 2-NBs(1H-benzo[d][1,2,3]triazole-1-yl2-nitrobenzenesulfonate), 4-NBs(1H-benzo[d][1,2,3]triazole-1-yl4-nitrobenzenesulfonate), NDPP(norborna-5-en-2,3-dicarboximidediphenylphosphate), N-HATU(N-[(dimethylamino)-1H-1,2,3-triazolo[4,5-b]-pyridine-1-ylmethylene]-N-methylmethanaminonium hexafluorophosphate N-oxide), N-CF3-HBTU(N-[6-trifluoromethyl(1H-benzotriazole-1-yl)-(dimethylamino)methylene]-N-methylmethanaminonium hexafluorophosphate N-oxide), N-CF3-TBTU(N-[6-trifluoromethyl(1H-benzotriazole-1-yl)-(dimethylamino)methylene]-N-methylmethanaminonium tetrafluoroborate N-oxide), N-HAPyU(1-(1- Pyrrolidinyl-1H-1,2,3-triazolo[4,5-b]pyridine-1-ylmethylene)pyrrolidinium hexafluorophosphate N-oxide), N-HATTU(N-[(dimethylamino)-1H-1,2,3-triazolo[4,5-b]-pyridine-1-ylmethylene]-N-methylmethanaminonium hexafluorophosphate N-sulfide), N-HBPyU((1H-benzotriazol-1-yl)(1-pyrrolidinylmethylene)pyrrolidinium hexafluorophosphate N-oxide), N-HBTU(N-[(1H-benzotri Azole-1-yl)(dimethylamino)-methylene]-N-methylmethanaminonium hexafluorophosphate N-oxide), N-TATU(N-[(dimethylamino)-1H-1,2,3-triazolo[4,5-b]-pyridine-1-ylmethylene]-N-methylmethanaminonium tetrafluoroborate N-oxide), N-TBTU(N-[(1H-benzotriazol-1-yl)(dimethylamino)-methylene]-N-methylmethanaminonium tetrafluoroborate N-oxide), NDPP(norborna-5-ene-2,3-diccarboxylate) Midodiphenyl phosphate), NMM (N-methylmorpholine), NO2-PyBOP (6-nitrobenzotriazole-1-yloxy)tris(pyrrolidino)phosphonium hexafluorophosphate), Oxyma (ethyl 2-cyano-2-(hydroxyimino)acetate), PIC (N-phenyl,N-isopropylcarbodiimide), PS (polymer supported), PS-DCC (polymer cyclohexylcarbodiimide), PS-EDC (polymer 1-ethyl-3-(30-dimethylaminopropyl)-carbodiimide), PEC (N-ethyl,N-phenylcarbodiimide), PS-TBTU (N-[(1H-benzotriazole-1-yl)(dimethylamino)-methylene]-N-methylmethanaminonium tetrafluoroborate N-oxide), PTF (benzyltriphenylphosphonium dihydrogen trifluoride), PyAOP ((7-azabenzotriazole-1-yl)oxy]tris(pyrrolidino)phosphonium hexafluorophosphate), PyBroP (bromotri(pyrrolidino)phosphonium hexafluorophosphate), PyCloP (chlorotri(pyrrolidino)phosphonium hexafluorophosphate), PyDOP ([(3,4-dihydro-4-oxo-1,2,3-benzotriazine-3-yl)oxy]-tris(pyrrolidino)phosphonium hexafluorophosphate), PyCloK ((, 6-Chlorobenzotriazole-1-yloxy)tris(pyrrolidino)phosphonium hexafluorophosphate), PyPOP ((pentafluorophenyloxy)tris(pyrrolidino)phosphonium hexafluorophosphate), PyDAOP ([(3,4-dihydro)-4-oxo-5-azabenzo-1,2,3-triazine-3-yl]tris(pyrrolidino)phosphonium hexafluorophosphate), PyFOP ([[6-(trifluoromethyl)benzotriazole-1-yl]oxy]-tris(pyrrolidino)phosphonium hexafluorophosphate), PyFNBOP ([4-nitro-6-(trifluoromethyl)benzotriazole-1-yl] PyNOP ([(6-nitrobenzotriazole-1-yl)oxy]tris(pyrrolidino)phosphonium hexafluorophosphate), PyOxm (O-[(cyano(ethoxycarbonyl)methylidene)-amino]-yloxytri(pyrrolidino)phosphonium hexafluorophosphate), PyTOP ((pyridyl-2-thio)tris(pyrrolidino)phosphonium hexafluorophosphate), SOMP (5-(succinimidyloxy)-3,4-dihydr (L-1-methyl2H-pyrrolium hexachloroantimonate), TATU (O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate), TAs (3H-[1,2,3]triazolo[4,5-b]pyridine-3-yl-4-methylbenzenesulfonate), TBs (1H-benzo[d][1,2,3]triazol-1-yl-4-methylbenzenesulfonate), TBCR1 (4-(4,6-dimethoxy-1,3,5-triazine-2-yl)-4-methylmorpholinium tetrafluoro TBCR2(1-(4,6-dimethoxy-1,3,5-triazine-2-yl)-1-methylpiperidinium tetrafluoroborate), TBCR3(1-(4,6-dimethoxy-1,3,5-triazine-2-yl)quinuclidinium tetrafluoroborate), TDBTU(2-(3,4-dihydro-4-oxo-1,2,3-benzotriazine-3-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate), TCFH(tetramethylchloroformamidinium hexafluorophosphate), TCP(2,4,5-Trichlorophenyl active ester), TDATU (O-(3,4-dihydro-4-oxo-5-azabenzo-1,2,3-triazine-3-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate), TDTU (2-(3,4-dihydro-4-oxo-1,2,3-benzotriazine-3-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate), TEFFH (tetraethylfluoroformamidinium hexafluorophosphate), TF MS-DEP (diphenyl(trifluoromethylsulfonyl)phosphoramide), TFFH (tetramethylfluoroformamidinium hexafluorophosphate), TNTU (2-(5-norbornene-2,3-dicarboximide)-1,1,3,3-tetramethyluronium tetrafluoroborate), TODT (S-(1-oxide-2-pyridinyl)-1,3-dimethyl-1,3-trimethylenethionium tetrafluoroborate), TOTT (S-(1-oxide- 2-Pyridinyl)-1,1,3,3-tetramethylthiouronium tetrafluoroborate), TOTU(O-[cyano(ethoxycarbonyl)methyleneamino]-N,N,N',N'-tetramethyluronium tetrafluoroborate), TPTU(2-(2-oxo-1(2H)-pyridyl-1,1,3,3-tetramethyluronium tetrafluoroborate), TSTU(2-succinimide-1,1,3,3-tetramethyluronium tetrafluoroborate), TOPPipU Examples include (2[2-oxo-1(2H)-pyridyl]-1,1,3,3-bis(pentamethylene)uronium tetrafluoroborate), T3P (2-propanephosphonic anhydride, PPAA), TPFTU (N,N,N',N'-bis(tetramethylene)-O-pentafluorophenyluronium tetrafluoroborate), TPhTU (2-phthalimide-1,1,3,3-tetramethyluronium tetrafluoroborate), and TPP (triphenylphosphine carbon tetrachloride).

[0220] In one embodiment, the base is selected from NR3, where R can be independently selected from H, alkyl, aryl, heteroaryl, alkenyl, alkynyl, benzyl, and allyl, which typically have at least one, often two or more, non-hydrogen R groups. In one embodiment, the base is DIPEA (N,N-diisopropylethylamine). In one embodiment, the base is NEt3 (triethylamine). In alternative embodiments, the base is selected from DMAP, (S)-C5Ph5-DMAP, (R)-C5Me5-DMAP, quinidine, quinine, TEA, DBU, TMEDA, imidazole, and K2CO3. In one embodiment, the base is quinine. In one embodiment, the base is dihydroquinine.

[0221] In one embodiment, the base is, but is not limited to, DABCO, 1,5-diazobicyclo[4.3.0]nona-5-ene, 1,8-diazabicyclo[5.4.0]unde-7-ene, DMAP, 2,6-lutidine, piperidine, pyrrole, 3-pyrrolin, 2H-pyrrole, 2-pyrrolin, pyrrolidine, carbazole, azaindole, isoindole, indole, 3H-indole, indoridine, indoline, pyridine, pipe Lysine, quinuclidine, 4H-quinolidine, isoquinoline, quinoline, 1,8-naphthyridine, tetrahydroquinoline, acridine, oxazole, isoxazole, benoxazole, benzothiazole, isothiazole, thiazole, benzimidazole, imidazole 2, imidazole, imidazolidine, tetrazole, 1,3,4-thiadiazole, 1,2,3-tetrazole, 1,2,4-triazole, benzotriazole, imida Zollpyridine, indazole, oxadiazole, phenodiazene, thiomorpholine, dithiane, phenoxazine, morpholine, pyrazole, 2-pyrazoline, pyrazolidine, quinazoline, cinnoline, pyrimidine, pteridine, phthalazine, 1,2,4-triazine, 1,3,5-triazine, piperazine, quinoxaline, phenazine, 1H-indazole, pyridazine, hydantoin, cinnoline, cyclazine, triazolepyridine, These are heterocyclic bases comprising 2,2,6,6-tetramethylpiperidine, 2,8,9-triisobutyl-2,5,8,9-tetraaza-1-phosphabicyclo[3.3.3]undecane, 2,8,9-triisopropyl-2,5,8,9-tetraaza-1-phosphabicyclo[3,3,3]undecane, 2,8,9-trimethyl-2,5,8,9-tetraaza-1-phosphabicyclo[3.3.3]undecane, and their substituted derivatives.

[0222] In alternative embodiments, the base is selected from DMAP, (S)-C5Ph5-DMAP, (R)-C5Me5-DMAP, quinidine, kinin, TEA, DBU, TMEDA, imidazole, and K2CO3. In one embodiment, the base is kinin.

[0223] In some embodiments, the specified activator is a uronium-type activator selected from HBTU, HATU, COMU, and TFFH, and the base is DIPEA. In one embodiment, the activator is COMU and the base is NEt3. In another embodiment, the activator is COMU and the base is DIPEA.

[0224] In some embodiments, the identified activator is a benzotriazole-based activator selected from HOBt, PyBOP, HATU, HBTU, HCTU, and TBTU, and the base is DIPEA. In one embodiment, the activator is a benzotriazole-based activator selected from HOBt, PyBOP, HATU, HBTU, HCTU, and TBTU, and the base is NEt3. In one embodiment, the activator is HATU, and the base is DIPEA. In one embodiment, the activator is HATU, and the base is NEt3.

[0225] In an alternative embodiment, the quinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate is coupled to compound 2 in step (a): [ka]

[0226] In one embodiment of the present invention, the production of the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate is (1.1.a) A step of coupling phenyl dichlorophosphate with benzyl alcohol to produce benzylphenyl phosphorochloride in situ, and then reacting this with L-alanine isopropyl ester hydrochloride to obtain isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate, [ka] (1.1.b) A step of debenzylation of isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate and in situ reduction of the kinin to obtain the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate, [ka] Includes.

[0227] In an alternative embodiment, isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate is debenzylated in step (1.b) in the presence of a tertiary amine other than kinin to obtain a tertiary amine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate. Non-limiting examples of tertiary amine salts of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate include DBU, DABCO, and diisopropylethylamine: [ka]

[0228] In an alternative embodiment of the present invention, the production of the dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate is (1.1.a) A step of coupling phenyl dichlorophosphate with L-alanine isopropyl ester hydrochloride to obtain isopropyl(chloro(phenoxy)phosphoryl)-L-alaninate, [ka] (1.1.b.1) A step of forming DABCO phosphate, followed by treatment with an aqueous calcium chloride solution to obtain calcium diphosphoamide dihydrate salt, [ka] (1.1.c) A step of treating with dihydroquinine under acidic conditions to obtain the dihydroquinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate, [ka] Includes.

[0229] In one embodiment, the calcium diphosphoamide dihydrate salt is crystalline. In one embodiment, the phosphate in step (1.1.b.1) is an alternative tertiary base, but is not limited to DBU, DMAP, and diisopropylethylamine. In one embodiment, step (1.1.c) is carried out in the presence of HCl.

[0230] Additional examples of tertiary amines that may be used in step (1.1.b) or step (1.1.b.1) include 1,5-diazobicyclo[4.3.0]nona-5-ene, 1,8-diazabicyclo[5.4.0]unde-7-ene, DMAP (4-dimethylaminopyridine), 2,6-lutidine, piperidine, pyrrole, 3-pyrrolin, 2H-pyrrole, 2-pyrrolin, pyrrolidine, carbazole, azaindole, isoindole, indole, and 3H-in Dol, indoridine, indoline, pyridine, piperidine, quinuclidine, 4H-quinolidine, isoquinoline, quinoline, 1,8-naphthyridine, tetrahydroquinoline, acridine, oxazole, isoxazole, benoxazole, benzothiazole, isothiazole, thiazole, benzimidazole, imidazole 2, imidazole, imidazolidine, tetrazole, 1,3,4-thiadiazole, 1,2,3-tetrazole, 1,2,4-tri Azole, benzotriazole, imidazolepyridine, indazole, oxadiazole, phenodiazene, thiomorpholine, dithiane, phenoxazine, morpholine, pyrazole, 2-pyrazoline, pyrazolidine, quinazoline, cinnoline, pyrimidine, pteridine, phthalazine, 1,2,4-triazine, 1,3,5-triazine, piperazine, quinoxaline, phenazine, IH-indazole, pyridazine, hydantoin, cinnoline, cyclazine Examples include triazolepyridine, 2,2,6,6-tetramethylpiperidine, 2,8,9-triisobutyl-2,5,8,9-tetraaza-1-phosphabicyclo[3.3.3]undecane, 2,8,9-triisopropyl-2,5,8,9-tetraaza-1-phosphabicyclo[3,3,3]undecane, 2,8,9-trimethyl-2,5,8,9-tetraaza-1-phosphabicyclo[3.3.3]undecane, and their substituted derivatives.

[0231] In one embodiment, the tertiary amine is chiral. Non-limiting examples of chiral tertiary amines that may be used in step (1.1.b) or step (1.1.b.1) include tetramisole, quinine, quinine acetate, quinidine gluconate, 9-epi-quinine, 3-hydroxyquinine, quinine N-oxide, hydroquinine 4-chlorobenzoate, hydroquinine-9-phenanthryl ether, quinidine, quinidine N-oxide, hydroquinidine, hydroquinidine 9-phenanthryl ether, hydroquinidine 4-methyl-2-quinolyl ether, and hydroquinine 4-methyl-2-quinolyl ether. Tel, O-desmethylquinidine, hydroquinidine 4-chlorobenzoate, L-(-)-α-amino-ε-caprolactam hydrochloride, D-(+)-α-amino-ε-caprolactam hydrochloride, (R)-(-)-1-amino-2-propanol, (S)-(+)-1-amino-2-propanol, chiral amino acids, brucine, cinconin, cinconidine, dihydrocinconidine, dihydrocinconin, O-methylcinconidine, cinconan-6',9-diol, cinconan-9-ol, (9S)-(±)-10,11-dihydro-6' -Methoxy-cinconan-9-ol, 7'-(trifluoromethyl)-10,11-dihydrocinconan-9-ol, cupreine, β-isocupreine, euprosin, ethylhydrocupreine, (+)-dehydroabiethylamine, (+)-dehydroabiethylamine, (S)-(-)-N,α-dimethylbenzylamine, ephedrine, pseudoephedrine, (S)-α-methyl-2-pyridinemethanol, (R)-α-methyl-2-pyridinemethanol, strychnine, (2R,4S,5R)-2-hydroxymethyl -5-ethylquinuclidine, (2S,4S,5R)-2-aminomethyl-5-ethylquinuclidine, (2R,5R)-(+)-5-vinyl-2-quinuclidine methanol, N-[3,5-bis(trifluoromethyl)phenyl]-N'-[(8a,9S)-10,11-dihydro-6'-methoxy-9-cinconanyl]thiourea, N-[3,5-bis(trifluoromethyl)phenyl]-N'-[(9R)-6'-methoxy-9-cinconanyl]thiourea, N-[3,5-bis(trifluoromethyl)phenyl]-N'-[(8a,Examples include 9S)-6'-methoxy-9-cinconanyl]thiourea, quinine ethyl carbonate, 9-acetoxyl vanone, (DHQD)2PHAL, (DHQ)2PHAL, (DHQD)2Pyr, (DHQ)2Pyr, (DHQD)2AQN, and their derivatives.

[0232] In an alternative embodiment, debenzylation of isopropyl((benzyloxy)(phenoxy)phosphoryl)-L-alaninate is carried out in the presence of dihydrokinin to obtain the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate: [ka]

[0233] In an alternative embodiment, diastereomer-enriched S of formula XVI p -A method for producing phosphoramidate nucleotides is provided. This method is (a) Compound 2 and the compound of formula XVII are brought into contact in the presence of the specified activators and bases described herein to obtain a diastereomerized compound of formula XVI. p - Obtaining phosphoramidate nucleotides, [ka] (b) Diastereomerized S of formula XVI p -Further purification of the phosphoramidate nucleotide to diastereomerally pure S of formula XVI with a diastereomer purity of over 90%, about 95%, or even over 99% p - To obtain purine phosphoramidate nucleotides, (c) Optionally, convert the compound of formula XVI into a pharmaceutically acceptable salt of the compound of formula XVI, Includes, in the formula, R 2 , R 4 , R 5 , R 6a , R 6b , and R 7This is as defined herein.

[0234] Non-limiting examples of compounds of formula XVII include: [ka] TIFF0007851034000162.tif246170 is one example.

[0235] In one embodiment, diastereomer-enriched S p -Purify phosphoramidate compound 1 or the nucleotide of formula VII, formula IX, formula XII, formula XIV, or formula XVI to obtain the corresponding diastereomerally pure S p -Purin phosphoramide nucleotides are obtained by selective crystallization from alkyl acetate such as ethyl acetate, or chlorinated solvents such as dichloromethane, ketone solvents such as acetone, aromatic solvents such as toluene, or mixtures thereof. In one embodiment, purification is carried out by crystallization from alkyl acetate, chlorinated solvent, ketone solvent, or mixtures thereof using acetonitrile or aliphatic hydrocarbons. In one embodiment, purification is carried out by crystallization from alkyl acetate such as isopropyl acetate. In a particular embodiment, purification is carried out by selective crystallization from a mixture of ethyl acetate and toluene.

[0236] In one embodiment, the purification process involves dissolving the concentrated mixture in an organic solvent, and then adding a poor solvent dropwise to the solution system to crystallize the concentrated mixture, where the organic solvent is C 1~8 Alcohol, C 2~8 Ether, C 3~7 Ketones, C 3~7 Ester, C 1~2 Chlorocarbon, and C 2~7 It contains a solvent selected from nitriles, and the poor solvent is C 5~12 Saturated hydrocarbons, C 6~12The solvent is selected from aromatic hydrocarbons and petroleum ethers. In one embodiment, the organic solvent is selected from ethyl acetate, tert-butyl methyl ether, isopropanol, or tetrahydrofuran. In one embodiment, the poor solvent is selected from petroleum ether or hexane.

[0237] In one embodiment, diastereomer-enriched S p -Purify phosphoramide nucleotide compound 1 to obtain a diastereomer of pure S p -The purine phosphoramide nucleotide compound 1 is obtained by crystallization from an alkyl acetate such as ethyl acetate or isopropyl acetate, or a chlorinated solvent such as dichloromethane, or a mixture thereof. In one embodiment, purification is carried out by crystallization from an alkyl acetate, a chlorinated solvent, or a mixture thereof using acetonitrile or an aliphatic hydrocarbon.

[0238] The acquisition of compound 1 by deprotection conditions of formula VII, formula IX, or formula XII is generally known to those skilled in the art and is described in Theodora W. Green, Protective Groups in Organic Synthesis, Third Edition, John Wiley & Sons (1999) (which is part of this specification by reference).

[0239] For example, R 1b , R 3a , and R 3b When the protecting group selected is tert-butoxycarbonyl (Boc), the protecting group(s) can be removed via the conditions described on pages 281 and 520-525, including the use of HCl in ¼, AcCl in MeOH, CF3COOH in PhSH, and TsOH in THF. In other embodiments, the protecting group(s) can be removed with DBU in MeOH.

[0240] R 1b , R 3a, and R 3b When the protecting group selected is benzyloxycarbonyl (Cbz), the protecting group(s) can be removed via the conditions described on pages 520-522, including hydrogenation conditions (H2 / Pd-C) and strongly acidic conditions (HBr, AcOH; 50% CF3COOH; 70% HF, pyridine, CF3SO3H; FSO3H and CH3SO3H). In other embodiments, the protecting group(s) can be removed with DBU in MeOH.

[0241] R 1b , R 3a , and R 3b If the protecting group selected from is a substituted benzyl group, the protecting group(s) can be removed via the conditions described on pages 86 to 101. For example, R 1 When the compound is para-methoxybenzyl, the deprotection conditions include DDQ(2,3-dichloro-5,6-dicyano-1,4-benzoquinone), CH2Cl2, and the catalyst DDQ(2,3-dichloro-5,6-dicyano-1,4-benzoquinone), FeCl3, CH2Cl2, and H2O.

[0242] R 1b , R 3a , and R 3b When the protecting group selected is para-methoxybenzyloxymethyl, the protecting group(s) can be removed via the conditions described on page 37, which include HCl in a 3:1 ratio of THF-6M.

[0243] Deprotection of compounds of formula VI, formula VIII, formula XI, or formula XIII (wherein R 1b Group, R 2 Group, R 3a Base, and / or R 3b(The group needs to be removed) is also generally known to those skilled in the art and is described in Theodora W. Green, Protective Groups in Organic Synthesis, Third Edition, John Wiley & Sons (1999) (which is part of this specification by reference). For example, R 1a The base can be removed as discussed above, R 3a Base and / or R 3b The base can be removed as described on pages 504-537 and 573-586 of the document. For example, R 3a and / or R 3b When R is a methyl carbamate, 3a and / or R 3b It can be removed using HBr in AcOH, R 3a and / or R 3b When R is a benzyl group, 3a and / or R 3b This can be removed using Pd / C in the presence of HCOOH.

[0244] Additional optional steps include: (b) Diastereomerally pure S p - A step of preparing a pharmaceutically acceptable salt form of purine phosphoramide nucleotide compound 1, These are some examples.

[0245] In one embodiment, the pharmaceutically acceptable salt form of compound 1 is the hemisulfate form, i.e., compound 1-A: [ka] That is the case.

[0246] In one embodiment, compound 1-A is prepared by adding concentrated H2SO4 in MeOH dropwise to compound 1 and filtering the resulting precipitate. In an alternative embodiment, compound 1-A is prepared by adding concentrated H2SO4 in acetone dropwise to compound 1 and filtering the resulting precipitate.

[0247] Non-limiting examples of compounds of formula XVI synthesized by the method of the present invention include: [ka] Alternatively, pharmaceutically acceptable salts thereof may be used. [Examples]

[0248] Example 1. Preparation of dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate [ka]

[0249] Phenyl dichlorophosphate (1-1, 150 g, 1.0 equivalent) was added to 1300 mL of isopropyl acetate. After cooling the solution to -10°C ± 5°C, solutions of benzyl alcohol (1-2, 80.6 g, 1.05 equivalent) and Et3N (86.3 g, 1.2 equivalents) were added. The mixture was stirred at -10°C ± 5°C for 3 hours. The endpoint of the reaction was monitored by TLC.

[0250] L-alanine isopropyl ester hydrochloride (1-4, 125 g, 1.05 equivalents) and Et3N (152 g, 2.1 equivalents) were added at -10°C ± 5°C. The reaction mixture was stirred at -10°C ± 5°C for 2 hours. The endpoint of the reaction was monitored by TLC.

[0251] The reaction mixture was filtered, and the filtered cake was washed with 20 mL of isopropyl acetate. The filtrate was washed with 1 N HCl, water, and aqueous sodium bicarbonate solution. The separated organic layer was dried over anhydrous Na₂SO₄ and then evaporated to dryness under vacuum at 40°C to 50°C to obtain 240 g of crude product 1-5 as a diastereomer mixture (approximately 1:1) (pale yellow oily substance; yield: 89.6% (mol / mol); HPLC purity: 83.4 area%; HPLC assay: 86.2% (g / g)). The product contained approximately 6% to 7% residual benzyl alcohol. Crude products 1-4 were used directly in the next step.

[0252] Compounds 1-5 (135 g, 1.0 equivalent, 86.2% (assay)) and kinin (100 g, 1.0 equivalent) were added to 650 mL of i-PrOH. After adding 5% Pd / C (19.2 g, 60% water (by KF)), hydrogenation was carried out in a sealed system at 20°C to 25°C for 8 hours using a hydrogen bag. After the reaction was complete, the mixture was filtered through a Buchner funnel. The filtrate was concentrated under vacuum to remove the solvent.

[0253] 300 mL of TBME was added to the above residue. The mixture was concentrated under vacuum at 40°C to 45°C to remove the solvent, and this process was repeated with another 300 mL of MTBE. 600 mL of MTBE was added to the above mixture, and the mixture was stirred at 40°C to 45°C for 1 hour, followed by stirring at 0°C to 5°C for another 1 hour. The mixture was filtered, and the filtered cake was washed with 100 mL of MTBE. The cake was dried at 45°C for 16 hours without vacuum to obtain 152 g of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate dihydrokinine salt (white solid; yield: 69.5% (mol / mol); HPLC purity: 97.91%).

[0254] Example 2. General preparation of Compound 2 [ka]

[0255] Step 1: Protect the (3S,4R,5R)-3,4-dihydroxy-5-(hydroxymethyl)-3-methyldihydrofuran-2(3H)-one at the 3' and 5' positions with the R protection group. 1a and R 1b Protect with to obtain the compound of formula A.

[0256] Step 2: The hydroxyl group is converted to fluorine by stereochemical inversion to obtain the compound of formula B.

[0257] Step 3: Next, the ketone on compound B is reduced to a hydroxyl group to obtain compound C. In certain embodiments, the reduction is stereoselective.

[0258] Step 4: Next, the hydroxyl group on compound C is replaced in a bromination reaction that inverts the stereocenter to obtain compound D.

[0259] Step 5: Next, the bromine on compound D is replaced with a nucleotide in a nucleophilic reaction to obtain compound E.

[0260] Step 6: Next, the nucleotides on the compound of formula E are reacted with methylamine to obtain the compound of formula F.

[0261] Step 7: Protecting group R on compound of formula F 1a and R 1b Remove the compound of formula G.

[0262] Example 3.R 1a Position and R 1b Preparation of compound 2 using a Cbz group at the position: [ka]

[0263] In step 1, compound 2-1 is dissolved in DMC, the reaction mixture is cooled to 10°C, benzyl chloroformate is added, followed by NEt3. The reaction mixture is cooled to room temperature and stirred for 12 to 14 hours. Compound 2-2 is isolated according to appropriate workup and purification conditions. In step 2, compound 2-2 is dissolved in acetonitrile, cooled to -15°C to 5°C, and then Morpho DAST is added. The reaction mixture is stirred for 6 hours. Compound 2-3 is isolated according to appropriate workup and purification conditions. In step 3, compound 2-3 is dissolved in toluene, the reaction mixture is cooled to 0°C to 10°C, and then Red Al is added. Compound 2-4 is isolated as a diastereomer having (R)-stereochemistry at the hydroxyl position according to appropriate workup and purification conditions. In step 4, compound 2-4 is dissolved in acetonitrile, cooled to -15°C to 5°C, and then CBr4 and PPh3 are added. Compounds 2-5 are isolated according to appropriate post-treatment and purification conditions. In step 5, compound 2-5 is dissolved in acetonitrile, and t-BuOH, t-BuOK, and 6-chloro-9H-purine-2-amine are added. The reaction mixture is heated to 40°C-50°C. Compound 2-6 is isolated according to appropriate post-treatment and purification conditions. In step 6, compound 2-6 is dissolved in MeOH, and MeNH2 is added. The reaction mixture is heated to 20°C-30°C. Compound 2 is isolated according to appropriate post-treatment and purification conditions.

[0264] In an alternative embodiment, compounds 2-4 are isolated as a mixture of diastereomers with respect to the stereochemistry at the hydroxyl group. After isolating the diastereomers, compound 2-4 is dissolved in DCM, the reaction mixture is cooled to 10°C, and then acetyl chloride is added. The reaction mixture is heated to room temperature and stirred. Compound 2-5' is isolated according to appropriate workup and purification conditions. In step 5', compound 2-5' is dissolved in acetonitrile, and 6-chloro-9H-purine-2-amine and SnCl4 are added. The reaction mixture is heated to 50°C to 65°C and stirred until complete. Compound 2-6 is isolated according to appropriate workup and purification conditions. Similarly, in step 6, compound 2-6 is dissolved in MeOH, and MeNH2 is added. The reaction mixture is heated to 20°C to 30°C. Compound 2 is isolated according to appropriate workup and purification conditions. [ka]

[0265] Example 4.R 1a Position and R 1b Preparation of compound 2 using cross-linked groups at the position [ka]

[0266] In step 1, a solution of compound 2-1 (1.0 mol) in DCM or THF and 2.5 to 3.0 mol of triethylamine can be slowly added to isophthaloyl dichloride (compound 2-7, 1.0 mol) in DCM or THF under controlled temperature, and the reaction mixture can be stirred until it appears complete by HPLC. Compound 2-8 can be isolated by work-up by extraction and purified by recrystallization from a suitable solvent (isopropyl alcohol, ethyl acetate, heptane, or a combination thereof). In step 2, compound 2-8 can be dissolved in acetonitrile, and after cooling to -15°C to 5°C, Morpho-DAST can be added. In an alternative embodiment, DAST is added instead of Morpho-DAST. The reaction mixture can be stirred for 6 to 8 hours. Compound 2-9 can be isolated according to appropriate work-up and purification conditions. In step 3, compound 2-9 can be dissolved in toluene, and after cooling the reaction mixture to 0°C to 10°C, Red-Al can be added. The reaction mixture can be stirred for 1 to 2 hours. In an alternative embodiment, compound 2-9 can be dissolved in THF, and DIBAL can be added after the reaction mixture has been cooled to -30°C. In this embodiment, the reaction mixture can be stirred for 2 to 4 hours. Compound 2-10 can be isolated as a diastereomer having (R)-stereochemistry at the hydroxyl position, subject to appropriate post-treatment and purification conditions. In step 4, compound 2-10 can be dissolved in acetonitrile, cooled to -15°C to 5°C, and then CBr4 and PPh3 can be added, and the reaction mixture can be stirred for 2 hours. Compound 2-11 can be isolated, subject to appropriate post-treatment and purification conditions. In step 5, compound 2-11 can be dissolved in acetonitrile, and t-BuOH, t-BuOK, and 6-chloro-9H-purine-2-amine can be added. The reaction mixture can be heated to 40°C to 50°C. Compound 2-12 can be isolated, subject to appropriate post-treatment and purification conditions. In step 6, compound 2-12 can be dissolved in MeOH, and an excess of MeNH2 can be added.The reaction mixture can be heated to 20°C-30°C and stirred for 8 hours. Compound 2 can be isolated according to appropriate workup and purification conditions.

[0267] Example 5.R 1a Position and R 1b Preparation of compound 2 using a -C(O)OCH3 group at the position: [ka]

[0268] In step 1, compound 2-1 is dissolved in THF, and methyl chloroformate and NEt3 are added. The reaction mixture is cooled to room temperature and stirred until complete. Compound 2-13 is isolated according to appropriate workup and purification conditions. In step 2, compound 2-13 is dissolved in acetonitrile, cooled, and then sulfonyl fluoride (SO2F2), triethylamine trifluoride (NEt3·3HF), and DBU are added. The reaction mixture is stirred until complete. Compound 2-14 is isolated according to appropriate workup and purification conditions. In step 3, compound 2-14 is dissolved in THF, cooled, and then Red-Al and ZnCl2 are added. Compound 2-15 is isolated as a diastereomer having (R)-stereochemistry at the hydroxyl position according to appropriate workup and purification conditions. In step 4, compound 2-15 is dissolved in ethyl acetate, cooled, and then CBr4 and PPh3 are added. Compound 2-16 is isolated according to appropriate post-treatment and purification conditions. In step 5, compound 2-16 is dissolved in acetonitrile and t-BuOH, t-BuOK, and 6-chloro-9H-purine-2-amine are added. The reaction mixture is heated to 40°C-50°C. Compound 2-17 is isolated according to appropriate post-treatment and purification conditions. In step 6, compound 2-17 is dissolved in MeOH and DIPEA is added. The reaction mixture is stirred until complete. Compound 2-18 is isolated according to appropriate post-treatment and purification conditions. In step 7, compound 2-18 is dissolved in MeOH and MeNH2 is added. The reaction mixture is heated to 20°C-30°C. Compound 2 is isolated according to appropriate post-treatment and purification conditions.

[0269] Example 6: R 1a Position and R 1b At position -C(O)OC 16 H 33 Preparation of compound 2 using the group: [ka]

[0270] Step 1: Preparation of Compound 2-19: Lactone compound 2-1 (10 g, 1.0 equivalent) and triethylamine (12.3 g, 2.2 equivalents) were dissolved in THF (100 mL). The solution was then cooled to approximately -10°C to 0°C, and hexadecyl carbonate chloride (34 g, 2.0 equivalents), diluted with THF (20 mL), was slowly added to the reaction mixture at approximately -10°C to 0°C over a period of no more than 2 hours. After stirring for 6 hours, the reaction was completed as confirmed by TLC monitoring. The formed triethylamine hydrochloride was then removed by filtration, and the solid was washed with THF (50 mL). The combined filtrate was concentrated to remove THF. Dichloromethane (200 mL) and water (100 mL) were then added with stirring. After separating the phases, the solvent was removed by concentration. Heptane (300 mL) was added to the residue, and the mixture was heated to 55°C to obtain a clear solution. After cooling the solution to 20°C-25°C, a solid precipitate formed from the mixture. After stirring at 20°C-25°C for 2 hours, the product was filtered, washed with heptane (10 mL), and dried at 50°C for 10 hours to obtain compound 2-19 (25 g) in 64% yield. 1 H NMR(400MHz,DMSO-d6) δ 5.18(d,1H), 4.56(dd,1H), 4.46~4.44(m,1H), 4.37(dd,1H), 4.20~4.15(m,4H ), 3.22(brd,1H), 1.69~1.65(m,4H), 1.47(s,3H), 1.25(m,52H), 0.88(m,6H).

[0271] Step 2: Preparation of Compound 2-20: NEt3-3HF (3.44 g, 1.5 equivalents) and DBU (6.6 g, 3 equivalents) were dissolved in dichloromethane (100 mL), and the mixture was cooled to below 10°C. Compound 2-19 (10 g, 1.0 equivalent), diluted with dichloromethane (20 mL), was added dropwise while bubbling SO2F2 gas. After monitoring the reaction by TLC and confirming completion (6 hours), water (100 mL) was added to quench the reaction. DCM (100 mL) was added to the mixture while stirring. The separated phase was then concentrated, and acetonitrile (100 mL) was added while heating (55°C-60°C) to obtain a clear solution. After cooling and stirring at 20°C to 25°C for 2 hours, the product was filtered, washed with acetonitrile (10 mL), and dried at 50°C for 6 hours to obtain compound 2-20 (9 g) in 90% yield. 1 H NMR(400MHz,DMSO-d6) δ 5.08(dd,1H), 4.72~4.71(m,1H), 4.58(dd,1H), 4.36(dd,4H), 4.27~4.13(m,4H), 1.76~1.57(m,7H), 1.26(m,52H), 0.89(m,6H).

[0272] Step 3: Preparation of Compound 2-21: Red-Al (6.3 mL, 1.5 equivalents, 70% solution in toluene) was added dropwise to anhydrous ZnCl2 (2.9 g, 1.5 equivalents) solution in THF at -20°C to -10°C. The mixture was stirred at this temperature for 30 minutes. Compound 2-20 (10 g, 14 mmol) was dissolved in THF (100 mL). The Red-Al-ZnCl2 solution prepared above was added dropwise to the reaction mixture at below -20°C, and the reaction mixture was stirred at -15°C to -5°C for 3 to 4 hours. The reaction mixture was then poured into 5% HOAc in water (100 mL). After extraction with 100 mL of ethyl acetate, the solvent was removed by concentration to obtain the crude product as a solid. The solid was dissolved by adding heptane (40 mL) while heating to 55°C. After cooling and stirring at 0°C to 10°C for 2 hours, the product was filtered, washed with heptane (10 mL), and dried at 40°C for 12 hours to obtain compound 2-21 (7.6 g) in 75% yield. 1H NMR(400MHz,DMSO-d6) δ 5.25(dd,1H), 5.51(dd,1H), 4.47~4.44(m,1H), 4.35~4.30(m,1H), 4.20~4.13(m,4H), 3.52(brd,1H), 1.70~1.67(m,4H), 1.55~1.50(m,3H), 1.38~1.27(m,52H), 0.90(m,6H).

[0273] Step 4: Preparation of Compound 2-22: Compound 2-21 (5.5 g, 7.82 mmol, 1.0 equivalent) was dissolved in DCM (30 mL), and the mixture was cooled to 0°C to 10°C under an N2 atmosphere. PPh3 (5.1 g, 19.44 mmol, 2.5 equivalents) was added to the solution at 0°C to 10°C, and CBr4 (5.2 g, 15.68 mmol, 2.0 equivalents) was added gradually. The reaction mixture was stirred at 5°C to 10°C for 1 hour, at which point TLC monitoring indicated that lactol had been completely consumed. MeOH (60 mL) was slowly added dropwise to the mixture at 20°C to 30°C. The mixture was stirred at 20°C to 30°C for 1 hour to remove OPPh3 and other impurities (excluding α / β isomers). A white solid was obtained by filtration and dried in an oven at 35°C for 3 hours to obtain 4.5 g of compound 2-22 in 75% yield (the α / β isomer ratio was approximately 3-4:1). 1 H NMR(400MHz,DMSO-d6) δ 6.33(dd,1H), 4.84(dd,1H), 4.64~4.58(m,1H), 4.54~4.52(m,1H), 4.44~4.36( m,1H), 4.23~4.15(m,4H), 1.76~1.64(m,7H), 1.39~1.25(m,52H), 0.90(m,6H).

[0274] Step 5: Preparation of compound 2-23: Cl-purine (2.65 g, 3 equivalents) and t-BuOK (1.8 g, 16.04 mmol, 3.0 equivalents) tThe reaction was added to BuOH (40 mL). The reaction was maintained at 55°C-60°C for 1 hour. Compound 2-22 (4.0 g, 5.22 mmol, 1.0 equivalent) in MeCN (60 mL) was added, and the reaction was maintained at 55°C-60°C overnight. TLC showed that the bromosaccharide was completely consumed. The reaction mixture was concentrated to remove most of the solvent, then ethyl acetate was added to remove the solid. The solution was neutralized with 1 N HCl. The organic phase was concentrated to obtain a concentrated oily substance, and methanol (30 mL) was added. After stirring for 1 hour, the solid precipitated, which was filtered and dried to obtain 3.8 g of crude product. The crude product was then dissolved in ethyl acetate (50 mL), and charcoal (1 g) was added. After filtering and concentration, the residue was crystallized from methanol (20 mL) to obtain pure compound 2-23 (2.5 g, 56% yield). The α-isomer was removed as shown by TLC. 1 H NMR(400MHz,DMSO-d6) δ 8.01(s,1H), 6.14(d,1H), 5.75(dd,1H), 5.52(brd,2H), 4.69(d,1H), 4.49~4.41 (m,2H), 4.21~4.10(m,4H), 1.70~1.66(m,3H), 1.36~1.25(m,56H), 0.89(m,6H).

[0275] Step 6: Preparation of Compound 2-18: Compound 2-23 (5 g, 5.85 mmol, 1.0 equivalent) was dissolved in MeOH (30 mL). DIPEA (1.51 g, 11.7 mmol, 2.0 equivalents) was added dropwise to the reaction mixture. The reaction mixture was then heated to 50°C and stirred at this temperature for 18 hours. Complete conversion was shown by TLC. The reaction mixture was concentrated, redissolved in MTBE (25 mL), and concentrated again. Then, MTBE (25 mL) was added, and the mixture was stirred as a slurry at room temperature for 30 minutes. The solid was filtered and drip washed with MTBE (5 mL). The collected solid was dried in an oven at 50°C to obtain 1.74 g of white solid powder as Compound 2-18 in 93% yield.

[0276] Step 7: Preparation of Compound 2: Compound 2-18 (1.5 g, 1.0 equivalent) was dissolved in THF (15 mL). An aqueous solution of MeNH2 (28%, 1.6 g, 3.0 equivalents) was added dropwise to the solution. The reaction mixture was stirred overnight at 20°C to 30°C until the starting materials were completely consumed. A solution of NaHCO3 (410 mg, 1.0 equivalent) in H2O (5 mL) was added to the reaction mixture. After stirring for 10 minutes, the mixture was concentrated under reduced pressure. The residue was redissolved in EtOH (20 mL). The concentration-division process was repeated twice, and the residue was stirred in EtOH (20 mL). The mixture was filtered to remove the salts, and the filtrate was concentrated. The residue was dissolved in HCl, and the solution was concentrated. Then, HCl (10 mL) was added, and the solution was stirred at 50°C for 0.5 hours, after which a solid precipitate formed. The mixture was slowly cooled overnight with stirring, the solid was filtered, and dried at 55°C for 7 hours to obtain 1.1 g of compound 2 in 75% yield and 97.36% purity (by area HPLC).

[0277] Example 7.R 1a Position and R 1b Preparation of compound 2 using a -C(O)NHPh group at the position: [ka]

[0278] In step 1, compound 2-1 is dissolved in THF and cooled to 0°C using an ice bath, after which compounds 2-24 and NEt3 are added. The reaction mixture is cooled to room temperature and stirred until complete. Compound 2-25 is isolated according to appropriate workup and purification conditions. In step 2, NEt3-3HF and DBU are dissolved in acetonitrile and the mixture is cooled to 0°C to 10°C. Compound 2-25, diluted in acetonitrile, is added dropwise while bubbling SO2F2 gas. The reaction mixture is stirred until complete. Compound 2-26 is isolated according to appropriate workup and purification conditions. In step 3, compound 2-26 is dissolved in toluene and the reaction mixture is cooled, after which LiAlH(Ot-Bu)3 is added. Compound 2-27 is isolated as a diastereomer having (R) stereochemistry at the hydroxyl position according to appropriate workup and purification conditions. In step 4, compound 2-27 is dissolved in ethyl acetate, cooled, and then CBr4 and PPh3 are added. Compound 2-28 is isolated according to appropriate workup and purification conditions. In step 5, compound 2-28 is dissolved in acetonitrile and t-BuOH, t-BuOK, and 6-chloro-9H-purine-2-amine are added. The reaction mixture is heated to 40°C to 50°C. Compound 2-29 is isolated according to appropriate workup and purification conditions. In step 6, compound 2-29 is dissolved in MeOH and MeNH2 is added. The reaction mixture is heated to 20°C to 30°C. Compound 2 is isolated according to appropriate workup and purification conditions.

[0279] Example 8.R 1a Position and R 1b Preparation of compound 2 using the -C(O)N(Ph)2 group at the position: [ka]

[0280] In step 1, compound 2-1 is dissolved in THF and cooled to 0°C using an ice bath, after which diphenylcarbamate chloride is added. The reaction mixture is cooled to room temperature and stirred until complete. Compound 2-30 is isolated according to appropriate workup and purification conditions. In step 2, NEt3-3HF and DBU are dissolved in acetonitrile and the mixture is cooled to 0°C to 10°C. Compound 2-30, diluted in acetonitrile, is added dropwise while bubbling SO2F2 gas. The reaction mixture is stirred until complete. Compound 2-31 is isolated according to appropriate workup and purification conditions. In the alternative reaction, fluorination is performed using DAST. In step 3, compound 2-31 is dissolved in toluene and, after cooling the reaction mixture, LiAlH(Ot-Bu)3 is added. Compound 2-32 is isolated as a diastereomer having (R) stereochemistry at the hydroxyl position according to appropriate workup and purification conditions. In step 4, compound 2-32 is dissolved in ethyl acetate, cooled, and then CBr4 and PPh3 are added. Compound 2-33 is isolated according to appropriate post-treatment and purification conditions. In step 5, compound 2-33 is dissolved in acetonitrile and t-BuOH, t-BuOK, and 6-chloro-9H-purine-2-amine are added. The reaction mixture is heated to 40°C to 50°C. Compound 2-34 is isolated according to appropriate post-treatment and purification conditions. In step 6, compound 2-34 is dissolved in MeOH and MeNH2 is added. The reaction mixture is heated to 20°C to 30°C. Compound 2-35 is isolated according to appropriate post-treatment and purification conditions. In step 7, compound 2-35 is dissolved in a suitable solvent and NaOEt is added. Compound 2 is isolated according to appropriate post-treatment and purification conditions.

[0281] Example 9. Preparation of Compound 1 [ka]

[0282] Isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate dihydrokinine salt (5.9 g, 1.5 equivalents), compound 2 (2.0 g, 1.0 equivalent), DIPEA (0.83 g, 1.0 equivalent), and HATU (3.65 g, 1.5 equivalents) were added to 100 mL of dichloromethane. The mixture was heated to 40°C and stirred for 18 hours. The reaction was monitored by TLC and HPLC.

[0283] After the reaction was complete, the reaction mixture was cooled to room temperature and washed with 1N hydrochloric acid (100 mL x 2), water (100 mL x 2), and a 5% sodium bicarbonate aqueous solution (15 mL x 1). The separated organic phase was dried over 2 g of anhydrous sodium sulfate, filtered, and concentrated under vacuum at 40°C to 45°C to obtain a yellow oily substance.

[0284] Isopropyl acetate (10 mL) was added. After stirring, the mixture was concentrated under vacuum. Then, 25 mL of isopropyl acetate was added. The mixture was heated to 45°C to obtain a clear solution. After stirring at room temperature for 2 hours, the solid precipitate was filtered and dried at 45°C for 15 hours without vacuum to obtain 2.0 g of crude compound 1 (Yield: 53.8% (mol / mol); HPLC purity: 93.1% (3.7% R) p -Contains compound 1).

[0285] A mixture of crude compound 1 (2.0 g) and 15 mL of isopropyl acetate was heated to 80°C to 85°C to obtain a solution. The solution was cooled to 20°C to 25°C and stirred for 1 hour. The precipitated solid was filtered, washed with isopropyl acetate (1 mL), and dried at 50°C for 16 hours without vacuum to obtain 1.7 g of compound 1 (yield: 45.7% (mol / mol); HPLC purity: 98.99%). 1 1H NMR, 19 F NMR, and 31 The structure of compound 1 was confirmed by the 1P NMR spectrum.

[0286] Example 10. Alternative preparation of Compound 1 and Compound 1-A [ka]

[0287] Isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate dihydrokinin salt, compound 2, kinin, and HATU are added to dichloromethane. The mixture is heated and stirred until complete by TLC and HPLC. Compound 1 is isolated under appropriate workup and purification conditions. Compound 1 is then dissolved in acetone and H2SO4 is added dropwise. The reaction is stirred until complete. Compound 1-A is isolated under appropriate workup and purification conditions.

[0288] Example 11. Preparation of Compound 2, Compound 1, and Compound 1-A Part A. Synthesis of dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate: [ka]

[0289] Phenylenide dichlorophosphate 1-1 (175 g, 1.0 equivalent) was added to 1750 mL of isopropyl acetate. After cooling the solution to -10°C ± 5°C, a solution of benzyl alcohol (95 g, 1.05 equivalent) and Et3N (105 g, 1.0 equivalent) was added. The mixture was stirred at -10°C ± 5°C for 3 hours to form benzylphenyl phosphorochloride intermediate 1-3. L-alanine isopropyl ester hydrochloride 1-4 (140 g, 1.0 equivalent) and Et3N (180 g, 2.1 equivalents) were added at -10°C ± 5°C. The reaction mixture was stirred at -10°C ± 5°C for 2 hours. The solid in the reaction mixture was then filtered, and the filtered cake was washed with 100 mL of isopropyl acetate. The filtrate was washed with water (750 mL), 1N HCl (750 mL), saturated sodium bicarbonate solution (750 mL), and water (750 mL). Charcoal (25 g) was added to the separated organic phase. After stirring at 25°C to 30°C for 2 hours, the mixture was filtered, and the cake was washed with 100 mL of isopropyl acetate. The combined filtrate was concentrated under vacuum at 40°C to 50°C to obtain 300 g of crude product compounds 1-5 (pale yellow oily substance; yield: 96% (mol / mol); HPLC purity: 91.5% area). 1 ¹H NMR (400MHz, chloroform-d) δ 7.37~7.13 (m, 10H), 5.13 (t, J=8.0Hz, 2H), 5.00~4.95 (m, 1H), 3.95~3.92 (m, 1H), 3.60 (q, J=8.0Hz, 1H), 1.35~1.29 (m, 3H), 1.22~1.18 (m, 6H).

[0290] Compounds 1-5 (300 g, 1.0 equivalent) and quinine (250 g, 0.9 equivalent) were added to 1750 mL of i-PrOH. After adding 5% wet Pd / C (45 g, 60% water (by KF)), hydrogenation was carried out at 20°C-25°C for 20 hours. The mixture was filtered through a Buchner funnel. The filtrate was concentrated to dryness under vacuum. MTBE (1000 mL) was added. The mixture was concentrated to dryness under vacuum at 40°C-45°C, and this step was repeated. MTBE (1500 mL) was added, and the mixture was stirred at 50°C for 1 hour, then stirred at 0°C-5°C for 1 hour. The mixture was filtered to obtain the crude product. Next, 1250 mL of acetonitrile was added to the cake. The mixture was heated under reflux to obtain a clear solution. The solution was then cooled to 0°C-10°C and stirred at this temperature for 3 hours. The precipitated solid was filtered, washed with 100 ml of cold acetonitrile, and dried at 45°C for 16 hours without vacuum to obtain 330 g of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate dihydrokinine salt (white solid; 2-step yield: 65% (mol / mol); HPLC purity: 99.4 area%). 1 H NMR(400MHz,DMSO-d6) δ 12.56(s,1H), 8.75(d,J=4.5Hz,1H), 7.97(d,J=9.2Hz,1H), 7.65(d,J=4.4Hz,1H), 7.55(d,J=2.6Hz,1H), 7.42(dd, J=9.2,2.6Hz,1H), 7.26~7.09(m,4H), 6.93(t,J=7.0Hz,1H), 6.56(s,1H), 6.06(s,1H), 4.80(h,J=6.2Hz,1H), 3.98 (s,5H), 3.77(q,J=7.7Hz,1H), 3.59(s,1H), 3.49(s,1H), 3.04(s,1H), 2.82(s,1H), 2.09~1.89(m,3H), 1.75(d,J=3 4.0Hz,2H), 1.46~1.33(m,1H), 1.33~1.18(m,2H), 1.15(d,J=7.0Hz,3H), 1.12~1.09(m,6H), 0.76(t,J=7.3Hz,3H).

[0291] Part B. Synthesis of Compound 2 [ka]

[0292] Step 1: Preparation of Compound 2-13: Compound 2-1 (20 g, 1.0 equivalent) was dissolved in THF (100 mL), and the solution was cooled to -55°C to 5°C. Then, Et3N (22.4 g, 2.0 equivalent) and methyl chloroformate (21 g, 2.0 equivalent) were simultaneously added dropwise to the reaction mixture at -15°C to 5°C. The addition was completed within 1 hour, and the reaction mixture was stirred at this temperature for a further 3 hours. After filtering the formed triethylamine hydrochloride, the filtrate was concentrated at 40°C to 45°C. Then, toluene (60 mL) and H2O (15 mL) were added over 5 hours at 0°C to 10°C with stirring. The precipitated solid was filtered, washed with water (20 mL), and dried at 45°C to 50°C for 8 hours to obtain Compound 2-13 as a white solid (24 g) in 78% yield. 1 H NMR (400MHz, DMSO-d6) δ 5.23(d,1H), 4.58(dd,1H), 4.49~4.45(m,1H), 4.42~4.37(m,1H), 3.87(s,3H), 3.83(s,3H), 3.02(brd,1H), 1.46(s,3H).

[0293] Step 2: Preparation of Compound 2-14: NEt3-3HF (6.1 g, 1.5 equivalents) and DBU (11.5 g, 3 equivalents) were dissolved in acetonitrile (35 mL), and the mixture was cooled to 0°C to 10°C. Compound 2-13 (7 g, 1.0 equivalent), diluted with acetonitrile (14 mL), was added dropwise while bubbling SO2F2 gas. After monitoring the reaction by TLC and confirming completion (2 hours), water (70 mL) was added to quench the reaction. DCM (70 mL) was added to the mixture while stirring. The separated phase was then concentrated, and i-propanol (100 mL) was added while heating (55°C to 60°C) to obtain a clear solution. After cooling and stirring at 0°C to 10°C for 2 hours, the product was filtered, washed with i-propanol (5 mL), and dried at 50°C to obtain compound 2-14 (6 g) in 85% yield. 1H NMR (400MHz, DMSO-d6) δ 5.09(dd,1H), 4.71(m,1H), 4.59(dd,1H), 4.37(dd,1H), 3.88(s,3H), 3.82(s,3H), 1.76(d,3H).

[0294] Step 3: Preparation of Compound 2-15: Anhydrous ZnCl2 (14.6 g, 0.107 mol, 1.5 equivalents) was added to THF (200 mL) at 20°C to 25°C. After stirring for 30 minutes, Compound 2-14 (20 g, 0.07 mol, 1.0 equivalent) was added to the solution. The mixture was cooled to -20°C to -10°C, and Red-Al (31 g, 0.107 mol, 1.5 equivalents, 70% solution in toluene) was added dropwise within 2 hours at this temperature. After stirring the reaction mixture for a further 1 hour, the starting materials were completely consumed as observed by TLC. The reaction mixture was poured into 10% HOAc in water (200 mL) at below 10°C. Then, toluene (200 mL) was added to separate the phases. The aqueous phase was extracted once with toluene (100 mL). The combined organic phases were washed with sodium bicarbonate solution (100 mL, 5%). The organic solution was concentrated to approximately 30 mL, and the mixture was cooled to 0°C to 10°C and stirred for 2 hours. The precipitated solid was filtered, washed with toluene (5 mL), and dried at 40°C for 12 hours to obtain compound 2-15 (15.3 g) in 75% yield. 1 H NMR (400MHz, DMSO-d6) δ 7.23(d,1H), 4.97(m,1H), 4.84(dd,1H), 4.38(m,1H), 4.12(m,1H), 3.77(s,3H), 3.74(s,3H), 1.37(d,3H).

[0295] Step 4: Preparation of Compound 2-16: Compound 2-15 (12 g, 1.0 equivalent, α / β ratio of approximately 13 / 87) was dissolved in ethyl acetate (60 mL), and the mixture was cooled to 0°C to 10°C under an N2 atmosphere. PPh3 (17.9 g, 1.6 equivalents) was added to the solution at 0°C to 10°C, and CBr4 (21.1 g, 1.5 equivalents) was added gradually. The reaction mixture was stirred at 5°C to 10°C for 2 hours, at which point TLC monitoring indicated complete consumption of lactol. The precipitated solid was removed by filtration, and the solid was washed with ethyl acetate (2 × 5 mL). The filtrate was then washed with sodium bicarbonate solution (20 mL, 5%) and dried over anhydrous sodium sulfate. Heptane (250 mL) was added to the ethyl acetate solution, and the solid was precipitated. The solid was filtered, washed with heptane (10 mL), and dried at 40°C for 4 hours to obtain 13 g of Compound 2-16. The yield was calculated to be 62% by HPLC measurement. The analytical sample was prepared by column chromatography using a heptane / ethyl acetate = 20:1 eluent. 1 H NMR (400MHz, DMSO-d6) δ 6.25(s,1H), 4.84(dd,1H), 4.63~4.61(m,1H), 4.55(dd,1H), 4.42(dd,1H), 3.88(s,3H), 3.83(s,3H), 1.69(d,3H).

[0296] Step 5: Preparation of Compound 2-17: Cl-purine (6.4 g, 3 equivalents) and t-BuOK (4.2 g, 3.0 equivalents) were added to t-BuOH (45 mL). The reaction mixture was maintained at 55°C to 60°C for 1 hour. Then, a solution of Compound 2-16 (6.0 g, 72% (assay), 1.0 equivalent) in acetonitrile (65 mL) was added, and the reaction mixture was maintained at 55°C to 60°C overnight. TLC showed that the bromosaccharide had been completely consumed. The reaction mixture was cooled to 0°C to 10°C and neutralized with hydrochloric acid (37%, 1.1 mL). The solid was then removed by filtration, and the filtrate was concentrated. Ethyl acetate (20 mL) was added, and the resulting solid was again removed by filtration. The solution was then washed with water, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by column chromatography using a dichloromethane / methanol = 30:1 eluent to obtain compound 2-17 (2.82 g, 52% yield). 1 H NMR(400MHz,DMSO-d6) δ 8.29(s,1H), 7.09(s,2H), 6.27(d,1H), 5.69(dd,1H), 4.60(dd,1H), 4.53(dd,1H), 4.43~4.39(m,1H), 3.81(s,3H), 3.73(s,3H), 1.27(d,3H).

[0297] Step 6: Preparation of Compound 2-18: Compound 2-17 (2 g, 1.0 equivalent) and diisopropylethylamine (1.2 g, 2.0 equivalents) were added to methanol (10 mL). The mixture was then warmed overnight at 45°C to 50°C. After TLC indicated that the starting materials had been completely consumed, the reaction mixture was cooled to 0°C to 10°C with stirring. The precipitated solid was collected by filtration, washed with methanol (2 mL), and dried at 50°C for 7 hours to obtain 1.14 g of Compound 2-18 in 78.1% yield. 1 H NMR(400MHz,DMSO-d6) δ 8.44(s,1H), 7.09(s,1H), 6.10(d,1H), 5.70(d,1H), 5.26(t,1H), 4.22~4.16(m,1H), 3.95~3.84(m,2H), 3.72~3.71(m,1H), 1.15(d,3H).

[0298] Step 7: Preparation of Compound 2: An aqueous solution of MeNH2 (28%, 0.85 g, 3.0 equivalents) was added dropwise to a solution of Compound 2-18 (1.5 g, 1.0 equivalent) in THF (12 mL). The reaction mixture was stirred at 20°C to 30°C for 7 hours, at which point the starting materials were completely consumed. A solution of NaHCO3 (220 mg, 1.0 equivalent) in H2O (3 mL) was added to the reaction mixture. After stirring for 10 minutes, the mixture was concentrated under reduced pressure. The residue was redissolved in EtOH (15 mL). The concentration-division process was repeated twice, and the residue was stirred in EtOH (20 mL). The mixture was filtered to remove the salts, and the filtrate was concentrated. The residue was dissolved in HCl, and the solution was concentrated. Then, HCl (10 mL) was added, and the solution was stirred at 50°C for 0.5 hours, at which point a solid precipitate formed. The mixture was cooled to 0°C to 5°C over 3 hours, the solid was filtered, and the mixture was dried at 55°C for 8 hours to obtain 0.68 g of compound 2 in 86% yield. 1 H NMR(400MHz,DMSO-d6) δ 7.98(s,1H), 7.29(s,2H), 6.03~5.97(m,3H), 5.64(d,1H), 5.26(s,1H), 4. 23~4.17(m,1H), 3.91~3.83(m,2H), 3.70(m,1H), 2.89(s,3H), 1.23(d,3H).

[0299] Part C: Synthesis of Compound 1 and Compound 1-A [ka]

[0300] Step 1: Preparation of Compound 1: Isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate dihydroquinine salt (295 g, 1.5 equivalents), Compound 2 (100 g, 1.0 equivalent), DIPEA (41.5 g, 1.0 equivalent), and HATU (182.5 g, 1.5 equivalents) were added to 1500 mL of dichloromethane. The mixture was heated to 40°C and stirred for 18 hours. The reaction was monitored by TLC and HPLC.

[0301] Workup, step 1: After the reaction was complete, the reaction mixture was cooled to 0°C to 10°C. 6N hydrochloric acid (400 mL) was slowly added at 0°C to 10°C, causing most of the dihydroquinine hydrochloride to precipitate. The precipitated solid was filtered, and the filtrate was washed with 2N HCl (500 mL), 5% sodium bicarbonate aqueous solution (500 mL), and water (500 mL). The separated organic phase was concentrated under vacuum at 40°C to 45°C to obtain a yellow oily substance.

[0302] Step 2: Isopropyl acetate (400 mL) and water (5000 mL) were added to dissolve the oily substance. Then, 2N HCl was added to adjust the pH to 4 and form a salt. After standing for 10 minutes, the phases were sufficiently separated. Many impurities entered the upper organic phase, while the hydrochloride salt of compound 1 remained in the lower aqueous phase. The aqueous phase was then adjusted to pH 8 and washed with dichloromethane (1250 mL x 2) to extract compound 1 into the organic phase. After washing the combined organic phase with water (500 mL), charcoal (10 g) was added. After stirring at 25°C to 30°C for 2 hours, the mixture was filtered and the cake was washed with 20 mL of dichloromethane. The dichloromethane was removed by concentration, and 200 mL of isopropyl acetate was added and concentrated again to obtain a yellow oily product.

[0303] Step 3: Isopropyl acetate (600 mL) was added. The mixture was heated to 50°C to obtain a clear solution. After stirring at room temperature for 2 hours, the precipitate was filtered to obtain an off-white solid of crude compound 1.

[0304] Step 4 (Recrystallization): The crude compound 1 and 600 mL of isopropyl acetate were heated to approximately 50°C to obtain a solution. The solution was cooled to 20°C-25°C and stirred for 2 hours. The precipitated solid was filtered, washed with isopropyl acetate (50 mL), and dried at 45°C-50°C for 16 hours without vacuum to obtain 112.5 g of compound 1 (yield: 60.5% (mol / mol); HPLC purity: 99.1 area%). 1H NMR(400MHz,DMSO-d6) δ 7.81(s,1H), 7.38~7.34(m,3H), 7.24~7.18(m,3H), 6.07~6.00(m,4H), 5.76(d,J=6.8Hz,1H), 4.87~4.78(m,1H) , 4.44~4.40(m,1H), 4.34~4.29(m,1H), 4.10~4.06(m,1H), 3.81~3.78(m,1H), 2.88(s,3H), 1.22~1.12(m,12H).

[0305] Step 2: Preparation of Compound 2: Compound 1 (14 g) was added to acetone (180 mL), and the mixture was stirred at 20°C to 30°C to obtain a solution. Then, sulfuric acid (1.12 g, 0.475 equivalents) was slowly added at 15°C to 20°C (within 30 minutes), and the solid gradually precipitated. The mixture was stirred at 15°C to 20°C for 30 minutes, and then stirred at 40°C to 45°C for 12 hours. The mixture was then cooled to 25°C to 30°C within 2 hours and stirred at this temperature for 1 hour. The solid was filtered and rinsed with acetone (28 mL). The wet substance was dried in air at 55°C for 15 hours to obtain Compound 2 (13.3 g) in 88% yield. 1 H NMR(400MHz,DMSO-d6) δ 8.42(brd,1H), 7.96(s,1H), 7.38~7.34(m,2H), 7.22~7.17(m,3H), 6.68(brd,2H), 6.09~5.99(m,2H), 5.81(brd,1) H), 4.82~4.79(m,1H), 4.43~4.28(m,3H), 4.11~4.07(m,1H), 3.80~3.77(m,1H), 2.90(s,3H), 1.22~1.09(m,12H).

[0306] Example 12. Large-scale production of Compound 1, Compound 1-A, and Compound 2: Part A: Synthesis of Compound 2: [ka]

[0307] Step 1: Preparation of Compound 2-36: Ethanol (24 kg) was placed in a 50 L four-necked double-walled glass flask equipped with a mechanical stirrer, addition funnel, condenser, and thermometer. Compound 2-35 (6 kg, 24.17 mol, 1 equivalent) was added all at once at 10°C to obtain a suspension. The mixture was heated to 25°C over 20 minutes to obtain a clear solution. While the internal temperature reached 32°C from 25°C, hydrochloric acid (36%, 6.1 kg, 60.42 mol, 2.5 equivalents) was added dropwise over 2 hours to obtain a pale yellow clear solution. The reaction mixture was heated at 79°C ± 2°C for 16 hours while maintaining gentle reflux, at which point TLC (DCM:MeOH = 10:1, 1% aqueous KMnO4 solution as chromogenic reagent) indicated that compound 2-30 had been completely consumed. The mixture was cooled to 40°C-45°C. The reaction mixture was transferred to a rotary evaporator (50 L) and concentrated under vacuum (less than 0.09 MPa) while maintaining a temperature of 60°C ± 5°C (water bath) through a condenser until no more fractions flowed out, yielding a brownish, viscous (rope) liquid. Anhydrous ethanol (12 kg) was added and evaporation was repeated. An additional anhydrous ethanol (12 kg) was added and evaporation was repeated once more. The crude product (oil) was dissolved in ethyl acetate (12 kg) at 50°C ± 5°C to obtain a clear solution (no acetylated impurities were observed) and transferred to a 50 L reactor. While maintaining the internal temperature between 25°C ± 5°C, water (0.625 kg, 34.72 mol, 1.5 equivalents) was added dropwise over 1 hour. After a further 0.5 hours with stirring, a solid precipitate formed. The resulting suspension was stirred at 15°C ± 5°C for 16 hours. The solid was filtered and washed with ethyl acetate (3 kg). The moist cake was dried in an air oven at 45°C ± 5°C for 16 hours without using a vacuum. Compound 2-36 (3.821 kg) was obtained as a white solid in 87.8% yield. 1 H NMR (DMSO-d6): δ 5.82~5.75(m,2H), 5.11~5.08(bs,1H), 4.02~3.95(m,2H), 3.74~3.71(m,1H), 3.53~3.48(m,3H), 1.19(s,3H).

[0308] Step 2: Preparation of Compound 2-37: Toluene (37.5 kg) was added to a 50 L four-necked double-walled glass reactor equipped with a mechanical stirrer, an addition funnel, a condenser, and a thermometer. Compound 2-36 (7.5 kg, 41.63 mol, 1 equivalent) was added to the reactor all at once. The mixture was heated and crystalline water was removed by azeotropic distillation. When the temperature rose to 86°C, water began to separate. After 8 hours, azeotropic distillation was completed and 700 g of water was collected. The reaction mixture was cooled to 40°C ± 5°C and transferred in two batches to a rotary evaporator (50 L). The solution was then concentrated under vacuum (less than 0.09 MPa) at 50°C ± 5°C to obtain a light brown liquid. Tetrahydrofuran (7.5 kg) was added and the mixture was concentrated under vacuum (less than 0.09 MPa) at 50°C ± 5°C to obtain a light brown liquid. Tetrahydrofuran (7.5 kg) was added again, and the mixture was concentrated under vacuum (less than 0.09 MPa) at 50°C ± 5°C until no more fraction flowed out through a condenser, yielding a light brown oily substance. The oily substance was dissolved in tetrahydrofuran (30 kg) at 50°C ± 5°C to obtain a clear solution, which was then transferred to a 50 L four-necked double-walled glass reactor. DMAP (0.51 kg, 4.16 mol, 2.0 equivalents) was added to the reactor, and the mixture was cooled to 2°C. Next, a solution of (Boc)2O (18.17 kg, 83.26 mol, 2.0 equivalents) in tetrahydrofuran (9 kg) was added to the reactants over 8 hours at 0°C to 10°C. Next, the reaction mixture was stirred at this temperature for a further 3 hours, at which point complete consumption of compound 2-36 was indicated by TLC (PE:EA = 5:1 → 1:1, with a 1% aqueous solution of KMnO4 as a chromogenic reagent). The reaction mixture was transferred in four batches to a rotary evaporator (50 L), and then concentrated under vacuum (less than 0.09 MPa) at 50°C ± 5°C until no more fractions flowed out through a condenser, yielding a pale yellow oil. In two batches, the oil was transferred to a 50 L reactor. Water (28 kg) was added to the oil over 2 hours while stirring and maintaining the internal temperature between 15°C ± 5°C. A white solid precipitated during the addition of water. The resulting suspension was stirred at 15°C ± 5°C for 16 hours. The solid was filtered to obtain two batches of crude product.Two batches of moist cake were combined and dissolved in dichloromethane (11.25 kg) with stirring. After standing for 30 minutes, the phases were separated. The upper aqueous phase was discarded. The amount of separated water was 2.8 kg. The separated organic phase was then transferred to a rotary evaporator (50 L) and concentrated to half its volume at 45°C ± 5°C under vacuum (less than 0.07 MPa). The suspension was transferred to a 50 L reactor. Heptane (22.5 kg) was added with stirring. The mixture was slurryed at 15°C to 20°C for 16 hours. The solid was filtered and the cake was washed with heptane (5 kg). The moist cake was dried in an air oven at 45°C ± 5°C for 16 hours. Compound 2-37 (11.285 kg) was obtained as a white solid in 74.8% yield. 1 H NMR (CDCl3): δ 5.10~5.08(m,1H), 4.51~4.45(m,2H), 4.31~4.27(m,1H), 3.44~3.43(bs,1H), 1.53~1.46(m,21H).

[0309] Step 3: Preparation of Compound 2-38: DCM (12 kg) was placed at 12°C in a 50 L double-walled glass flask with four necks, equipped with a mechanical stirrer, addition funnel, condenser, and thermometer. Et3N-3HF (7.2 kg, 44.7 mol, 1.5 equivalents) was added to the reactor all at once to obtain a colorless, clear solution. The temperature was not changed. The mixture was then cooled to 0°C. DBU (13.6 kg, 89.4 mol, 3.0 equivalents) was added to the solution over 2 hours while maintaining the temperature between 0°C and 10°C by jacket cooling. The mixture was first degassed under a vacuum of less than 0.09 MPa. Next, while purging with SO2F2 (4 kg, 39.1 mol, 1.3 equivalents), a solution of compound 2-37 (10.8 kg, 29.8 mol, 1.0 equivalent) in DCM (10.8 kg) was simultaneously added dropwise to the reactor at 0°C to 10°C over 2 hours. The reaction mixture turned dark brown. After the addition of compound 2-37, SO2F2 was purged for another 2 hours. After bubbling a total of 4 kg of SO2F2, the reaction mixture was stirred for a further 16 hours at 15°C ± 5°C, at which point complete consumption of compound 2-37 was indicated by TLC (PE:EA = 3:1, with 1% aqueous KMnO4 as a chromogenic reagent). The reaction mixture was then transferred in two batches to a rotary evaporator (50 L). Both batches were carried over separately. First, these batches were concentrated to half their volume under vacuum (less than 0.07 MPa) at 20°C ± 5°C. 15 kg of water was added to a 50 L double-walled four-necked glass flask, and the reaction mixture was quenched in water at 0-5°C within 15 minutes while stirring. The mixture was then stirred for a further 10 minutes. After standing for 30 minutes, the phases were separated. The upper aqueous phase was discarded. The separated organic phase was washed with water (15 kg) for approximately 10 minutes while stirring. After standing for 30 minutes, the phases were separated. The upper aqueous phase was discarded. The separated organic phase was washed again with water (15 kg) for approximately 10 minutes while stirring. After standing for 30 minutes, the phases were separated. The upper aqueous phase was discarded. The separated organic phase was transferred to a rotary evaporator (50 L) and concentrated to half its volume under vacuum (less than 0.07 MPa) at 20°C ± 5°C. Isopropanol (21.6 kg) was added. The mixture was then concentrated to half its volume under vacuum (less than 0.07 MPa) at 45°C ± 5°C. Precipitation began during the concentration process.First and second batches of the substance were obtained. The two batches of the substance were combined and transferred to a 50 L reactor. Isopropanol (21.6 kg) was added over 1 hour with stirring. The mixture was stirred at 0°C to 5°C for 16 hours. The solid was filtered, and the cake was washed with isopropanol (8 kg). The moist cake was dried in an air oven at 45°C ± 5°C for 16 hours to obtain compound 2-38 (9.2 kg) in 85% yield. 1 H NMR (CDCl3): δ 5.04~4.99(m,1H), 4.73~4.70(m,1H), 4.87~4.45(m,1H), 4.33~4.28(m,1H), 1.78~1.72(m,3H), 1.53~1.50(m,18H).

[0310] Step 4: Preparation of Compound 2-39: A mechanical stirrer, an addition funnel, and a thermometer were installed in a 50 L four-necked glass reactor. Anhydrous THF (26.65 kg) was added to the reactor. Anhydrous ZnCl2 (1.68 kg, 12.351 mol, 1.5 equivalents) was added to the reactor at a temperature of 25°C ± 5°C to obtain a turbid solution, which was stirred at room temperature for 0.5 hours. Compound 2-38 (3 kg, 8.234 mol, 1.0 equivalent) was added to the reactor at a temperature of 25°C ± 5°C to obtain a turbid solution, which was stirred at room temperature for approximately 0.5 hours. Red-Al (3.57 kg, 12.351 mol, 1.5 equivalents) was added under a nitrogen atmosphere at -20°C to -30°C over 3 hours, and the mixture was stirred for approximately 30 minutes. At this point, TLC (PE:EA = 10:1, with 1% aqueous KMnO4 as a colorimetric reagent) indicated complete consumption of the starting material. While maintaining the reaction solution temperature below -10°C, acetic acid (3 kg, 49.404 mol, 6.0 equivalents) was added to the reaction solution. The reaction solution was then poured into a mixture of toluene (27 kg) and cold water (24 kg). While maintaining the reaction solution temperature below -5°C, hydrochloric acid (10%, 21 kg, 1.0 mol, 7.3 equivalents) was added to adjust the pH to 2-3. After stirring for 5 minutes, the layers were separated. The aqueous phase was extracted again with toluene (13.5 kg). The combined organic phase was washed with water (13.5 kg). While maintaining the temperature below 35°C, the separated organic phase was concentrated under a vacuum of less than 0.09 MPa to remove most of the THF. Toluene (27 kg) was added to obtain a clear solution, and the solution was washed with water (13.5 kg). The organic phase was washed with an aqueous solution of NaHCO3 (5%, 13.5 kg). The organic phase was washed with water (13.5 kg). Charcoal (300 mg) was added to the separated organic phase. After stirring at 20°C to 30°C for 1 hour, the mixture was filtered, and the cake was washed with toluene (5 kg). The combined filtrate was concentrated at 40°C to 60°C under a vacuum of less than 0.09 MPa to obtain the crude product compound 2-39 as an oil. Methanol (4.2 kg) was added at 40°C to obtain a clear solution. The solution was then cooled to 20°C to 30°C and slowly added to water (18 kg) at 10°C to 20°C over 2 hours. Seed (0.02 kg) of compound 2-39 was added. After stirring at 15°C to 20°C for 18 hours, the precipitated solid was filtered to obtain an off-white solid.The solid was dried at 45°C for 22 to 24 hours without using a vacuum to obtain 2706 g of compound 2-39 as a white solid (yield: 90%) (in d6-DMSO). 1 (H NMR measurement revealed α / β = 3:97). 1 H NMR (DMSO-d6): δ 7.19(d,1H), 5.08(m,1H), 4.89(m,1H), 4.26(m,1H), 4.07(m,2H), 1.43(m,18H), 1.34(m,3H).

[0311] Step 5: Preparation of Compound 2-40: Acetonitrile (10.67 kg) was added to a 50 L four-necked glass reactor equipped with a mechanical stirrer, an addition funnel, and a thermometer at -5°C ± 5°C. Triphenylphosphine (4.75 kg, 18.45 mol, 2.5 equivalents) was added all at once, the suspension was cooled, and stirred at -5°C ± 5°C for 30 minutes. Compound 2-39 (2.7 kg, 7.37 mol, 1.0 equivalent) was added all at once to the suspension at this temperature. Dibromohydantoin (2.75 kg, 9.59 mol, 1.3 equivalents) was added to the resulting mixture in 20 portions over 90 minutes at an internal temperature between -5°C ± 5°C (the suspension became a clear solution after half of the dibromohydantoin had been added; after the complete addition, the reaction solution turned slightly red). The reaction mixture was stirred for a further 1 hour at -5°C ± 5°C, at which point TLC (PE:EA = 10:1, 1% aqueous KMnO4 solution as chromogenic reagent) indicated that the reaction was complete. The α / β ratio in the reaction mixture was 86.6 / 13.4 based on TLC. A solution of sodium sulfite (0.56 kg, 4.44 mol, 0.6 equivalents), water (10 kg), and sodium bicarbonate (1.24 kg, 14.76 mol, 2.0 equivalents) was added dropwise to the reaction mixture via an additive funnel at 0°C ± 5°C. Some of the inorganic salts precipitated. The upper organic phase was separated, and the aqueous phase and precipitated inorganic salts were discarded (the α / β ratio in the reaction mixture was 86.6:13.4 by HPLC). Ethanol (10.65 kg) was added to the organic phase at 0°C ± 5°C to obtain a clear solution. Next, water (20 kg) was added dropwise to the solution via an addition funnel over 30 minutes, and a solid precipitated. After adding water, the mixture was stirred for a further 0.5 hours at 0°C ± 5°C. The solid was filtered to obtain 3.1 kg of a moist white solid. Ethanol (8.5 kg) was added to the reaction kettle and slurrying was carried out at 0°C ± 5°C for 0.5 hours. The solid was filtered and dried at 45°C for 16 hours without vacuum. After drying, 2388 g of a white solid was obtained with a purity of 97.3% and a yield of 76%. (HPLC showed that 1.8% of the β-isomer remained.)

[0312] Step 6: Preparation of Compound 2-42: Compound 2-41 (52.1 g, 308.25 mmol, 3.3 equivalents) was placed in a 2.0 L four-necked flask equipped with a mechanical stirrer, thermometer, condenser, and drying tube. Tert-amyl alcohol (323.6 g) was added to the flask and the mechanical stirrer was activated. Potassium tert-pentylate (35.4 g, 280.42 mmol, 3.0 equivalents) was added to the suspension all at once. The mixture was heated at 50°C ± 5°C for 30 minutes. The mixture was then stirred at 50°C ± 5°C for 1 hour. After heating for about 20 minutes, the reaction product became a clear solution, after which a solid precipitate formed. Acetonitrile (474 ​​g) was added all at once. Compound 2-40 (40 g, 93.44 mmol, 1.0 equivalent) was added all at once and maintained at 50°C ± 5°C for 12 to 16 hours. TLC indicated that the reaction was complete. The reactants were cooled to 0°C ± 5°C. Hydrochloric acid (36%, 18.864 g) was added dropwise to the reactants at 5°C ± 5°C to adjust the pH to 5-6. The mixture was stirred for a further 30 minutes. The suspension was filtered through a Celite pad. The filtrate cake was washed twice with acetonitrile (63.2 g), and the filtrates were combined. The filtrates were concentrated to approximately 20-30 ml of solvent at 50°C ± 5°C under vacuum (-0.1 MPa). Heptane (278 g) was added and the mixture was further concentrated to approximately 20-30 ml of solvent under those conditions. The mixed solvent (EA (360.8 g): heptane (55.6 g) = 1:5) was then added at 30°C ± 5°C. Silica gel (200-300 mesh, 40 g) was added to the solution and stirred at 30°C ± 5°C for 1 hour, and the mixture was filtered. The filtered cake was washed three times with a mixed solvent (EA (180.4 g): heptane (27.8 g) = 1:5). The filtrates were combined and concentrated in a vacuum at 50°C ± 5°C to obtain a yellow foamy solid (40 g).

[0313] Steps 7 and 8: Preparation of compound 2-44: Crude compound 2-42 (40 g, 77.5 mmol, 1.0 equivalent) from the last step was added to a 500 ml three-necked glass bottle equipped with a thermometer. THF (178 g) was added at 15°C, and the solution was stirred until the substance dissolved and a homogeneous solution was formed. A methylamine aqueous solution (calculated as having a 25% content, 28.9 g, 232.6 mmol, 3.0 equivalents) was added all at once, and after addition, the internal temperature of the reaction system was lowered to approximately 5°C. The reaction system was heated to 30°C ± 5°C and maintained at 30°C ± 5°C for approximately 16 hours with stirring, at which point completion was indicated by TLC (DCM:MeOH = 20:1 under UV254). The reactants were concentrated to a small volume (approximately 50 ml) under vacuum (-0.1 MPa). Ethyl acetate (180g) was added, and the mixture was concentrated to a small volume (approximately 50ml) using a water pump under -0.1 MPa. Ethyl acetate (180g) and water (100g) were added, and the mixture was stirred for 30 minutes. After standing for 30 minutes, the phases were separated. Water (100g) was added to the upper organic phase and stirred for 30 minutes. After standing for 30 minutes, the phases were separated. Water (100g) was added to the upper organic phase and stirred for 30 minutes. After standing for 30 minutes, the phases were separated. The upper organic phase was concentrated under vacuum until no more liquid flowed out of the condenser, yielding compound 2-43 as a foamy solid, which was used directly in the next step.

[0314] Crude compound 2-43 was dissolved in methanol. An HCl / MeOH solution (2 mol / L, 116.3 g, 232.6 mmol, 3.0 equivalents) was added all at once. The mixture was heated under reflux and stirred for 15-20 minutes, after which a solid precipitated. The mixture was kept under reflux for approximately 2 hours, at which point TLC indicated completion (DCM:MeOH = 20:1 under UV254). The reaction mixture was cooled to 15°C and stirred for 2 hours. The solid was filtered and washed with a small amount of methanol (9.6 g) to obtain a wet crude product. Ethanol (96 g) was added to the wet product, and the mixture was heated under reflux for approximately 3 hours. The reaction mixture was then cooled to 15°C and stirred for approximately 2-3 hours. The reaction mixture was filtered and washed with a small amount of ethanol (9.6 g) to obtain a wet product. The moist cake was dried in an air oven at 60°C for 16 hours, and compound 2-44 was obtained in two steps as an off-white solid (22.9 g) with a yield of 77%.

[0315] Step 9: Preparation of Compound 2: Compound 2-44 (3.0 g, 7.79 mmol, 1.0 equivalent) was mixed with 2-methyltetrahydrofuran (25.68 g). Next, NaHCO3 solid (1.64 g, 1848 mmol, 2.5 equivalents) was added all at once, followed by water (3 g). The mixture was heated to 30°C ± 5°C and stirred for 30 minutes, after which Na2SO4 (3 g) was added and the reaction mixture was stirred for 30 minutes. The mixture was filtered, and the filtrate cake was washed with a small amount of 2-methyltetrahydrofuran (2.6 g). The phases of the filtrate were separated. The upper organic phase was concentrated to dryness under reduced pressure to obtain Compound 2 as a white solid in 95% yield.

[0316] Part B. Synthesis of dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate: [ka]

[0317] Steps 1 and 2: A 50 L four-necked glass reactor was fitted with a mechanical stirrer, an addition funnel, and a thermometer. Isopropyl acetate (25 kg) was added to the reactor, and the temperature of the reaction solution was maintained below 10°C. Phenyl dichlorophosphate (compound 1-1, 3.5 kg, 16.6 mol, 1.0 equivalent) was added to the reactor to obtain a clear solution, which was then cooled to -10°C + 5°C. Next, a solution of benzyl alcohol (compound 1-2, 1.89 kg, 17.43 mol, 1.05 equivalent), triethylamine (2.01 kg, 19.9 mol, 1.2 equivalent), and isopropyl acetate (3.1 kg) was added over 2 hours at -10°C + 5°C under a nitrogen atmosphere. The mixture was stirred at -10°C + 5°C for 1.5 hours, at which point completion was indicated by TLC (siRNA:PE=1:2, UV254). L-alanine isopropyl hydrochloride (compound 1-4, 2.78 kg, 16.6 mol, 1.0 equivalent) was placed in the reactor. Then, a solution of triethylamine (3.5 kg, 34.9 mol, 2.1 equivalents) and isopropyl acetate (155 kg) was added over approximately 2 hours at -10°C + 5°C under nitrogen protection. The mixture was stirred at -10°C + 5°C for approximately 1 to 2 hours, at which point completion was indicated by TLC (Â:PE=1:2, UV254). The reaction mixture was filtered, and the filtrate was washed with isopropyl acetate (2.0 kg). The filtrate was washed with water (15 kg) at below 10°C. The separated organic phase was washed with hydrochloride (1N, 15 kg) at below 10°C. The separated organic phase was washed with saturated sodium bicarbonate solution (15 kg) at below 10°C. The separated organic phase was washed with water (15 kg) at a temperature below 10°C. Charcoal (350 kg) was added to the separated organic phase. After stirring at 25°C to 30°C for 2 hours, the mixture was filtered, and the cake was washed with isopropyl acetate (2.0 kg). The combined filtrate was concentrated at 40°C to 50°C under a vacuum of less than 0.09 MPa to obtain the crude products, compounds 1-5 (6.19 kg; pale yellow oily substance; yield: 99% (mol / mol); HPLC purity: 90% (area percent)).

[0318] Step 3: A 20 L three-necked glass flask equipped with a mechanical stirrer and thermometer was placed in the reactor along with compounds 1-5. Isopropanol (8 kg) was added to the reactor. Kinin (2 kg, 6.17 mol, 1.0 equivalent) was added to the reactor to obtain a clear solution. 5% wet Pd / C (65% water (by KF), 300 kg) was added to the reactor. Hydrogenation was carried out with hydrogen at 1 atm at 20°C-25°C for 48-50 hours, at which point TLC showed complete consumption of kinin. The mixture was filtered through a Buchner funnel. The filtrate was concentrated to dryness at 50°C-60°C under a vacuum of less than 0.09 MPa to obtain the crude product, and heptane (5 kg) was added. The mixture was concentrated at 40°C-45°C under a vacuum of less than 0.09 MPa, and this process was repeated by adding fresh heptane (5 kg). Heptane (10 kg) was added, and the mixture was stirred at 15°C to 25°C for 2 to 3 hours. The mixture was filtered to obtain the crude product of dihydroquinine, which was then dried at 45°C for 16 hours without vacuum to obtain 1.86 kg of dihydroquinine (off-white solid; yield: 93% (mol / mol); HPLC purity: 99.4 area%).

[0319] In alternative step 3, dihydroquinine is added during the hydrogenation step: [ka]

[0320] Isopropanol (175 g) was placed in a 500 ml three-necked glass flask, and compound 1-5 (35 g) and dihydroquinine (27.2 g, 0.084 mol, 1.0 equivalent) were added to obtain a clear solution. 5% wet Pd / C (5 g, 60% water (by KF)) was added to the solution. Hydrogenation was carried out at 20°C-25°C for 20-24 hours, at which point completion was indicated by TLC. The mixture was filtered through a Buchner funnel. Charcoal (2 g) was then added. After stirring at 25°C-30°C for 2 hours, the mixture was filtered, and the cake was washed with isopropanol. The filtrate was concentrated to dryness at 50°C-60°C under a vacuum of less than 0.09 MPa to obtain the crude product, and methyl tert-butyl ether (100 g) was added. The mixture was concentrated at 40°C-45°C under a vacuum of less than 0.09 MPa, and this process was repeated. Methyl tert-butyl ether (120 g) was added, and the mixture was stirred at 50°C for 1 hour, then stirred at 0°C to 5°C for 1 hour. The mixture was filtered to obtain the crude dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate. Acetonitrile (100 g) was then added, and the mixture was heated under reflux to obtain a clear solution. The solution was then cooled to 0°C to 10°C and stirred at this temperature for 3 hours. The precipitated solid was filtered, washed with cold acetonitrile (10 g), and dried at 45°C for 16 hours without vacuum to obtain 37 g of dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate (off-white solid; 2-step yield: 65% (mol / mol); HPLC purity: 97.5 area%).

[0321] Part C: Synthesis of Compound 1 and Compound 1-A: [ka]

[0322] Step 1: Preparation of Compound 1: A mechanical stirrer and thermometer were attached to a 3 L three-necked glass flask. Dichloromethane (2100 g) was added to the reactor. Isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate didroquinine salt (295 g, 0.480 mol, 1.5 equivalents), Compound 2 (100 g, 0.320 mol, 1.0 equivalent), DIPEA (41.5 g, 0.320 mol, 1.0 equivalent), and HATU (182.5 g, 0.480 mol, 1.5 equivalents) were added to the reactor to obtain a turbid solution. The mixture was heated to 40°C and stirred for 18 to 20 hours, at which point TLC (siRNA:MeOH=15:1) and HPLC showed that Compound 2 had been completely consumed. The reaction mixture was cooled to 0°C to 10°C. When hydrochloric acid (6N, 400g, 2.40mol, 7.5 equivalents) was slowly added at 0°C to 10°C, most of the dihydroquinine hydrochloride precipitated. The precipitated solid was filtered and washed with HCl (2N, 500g), 5% sodium bicarbonate aqueous solution (500g), and water (500g). The separated organic phase was concentrated at 40°C to 45°C under a vacuum of less than 0.09 MPa to obtain a yellow oily substance. Isopropyl acetate (360g) and water (5000g) were added to dissolve the oily substance. HCl (2N) was added to adjust the pH to 4 and form a salt. After standing for 10 minutes, the phases separated sufficiently, with many impurities entering the upper organic phase and the hydrochloride of compound 1 remaining in the lower aqueous phase. The aqueous phase was then adjusted to pH 8 with sodium bicarbonate and washed with dichloromethane to extract compound 1 into the organic phase. The combined organic phases were washed with water, and charcoal (10g) was added. After stirring at 25°C to 30°C for 2 hours, the mixture was filtered, and the cake was washed with dichloromethane (15g). Dichloromethane was removed by concentration at 30°C to 50°C under a vacuum of less than 0.09 MPa. Isopropyl acetate (180g) was added, and concentration was performed again to obtain a yellow oily product. Isopropyl acetate (540g) was added. The mixture was heated to 50°C to obtain a clear solution. After stirring at room temperature for 2 hours, the precipitate was filtered to obtain an off-white solid of crude compound 1. Crude compound 1 and isopropyl acetate (540g) were heated to approximately 50°C to obtain a solution, which was cooled to 20°C to 25°C and stirred for 2 hours.The precipitated solid was filtered, washed with isopropyl acetate (45 g), and dried at 45°C to 50°C for 16 hours without vacuum to obtain 112.5 g of compound 1 (yield: 60.5% (mol / mol); HPLC purity: 99.1 area%).

[0323] Step 2: Preparation of Compound 1-A: Acetone (1000g) was placed in a glass flask while stirring at 20°C to 25°C, and compound 1 (100g, 0.172mol) was added to form a clear solution. While maintaining the internal temperature at 20°C to 25°C, concentrated sulfuric acid (98%, 8g, 0.082mol, 0.475 equivalents) was slowly added to the solution. The addition time was 60 minutes or more. The suspension was left to stand at an internal temperature of 20°C to 25°C for 30 minutes. The suspension was heated at an internal temperature of 40°C to 45°C for 16 hours while stirring. The suspension was cooled to an internal temperature of 20°C to 25°C within 2 hours, and then left to stand for 2 hours or more. The solid was filtered through vacuum filtration, and the moist filtration cake was washed with an appropriate amount of acetone (50g) at ambient temperature. The product was dried under vacuum at 40°C ± 5°C for more than 5 hours, and then further dried under vacuum at 55°C ± 5°C for more than 17 hours to obtain compound 1-A in 88% yield.

[0324] Example 13. Alternative large-scale production of Compound 1, Compound 1-A, and Compound 2: Alternative methods for preparing Compound 1, Compound 1-A, and Compound 2 are detailed below. In this method, crystallization of Compound 2-42 from DCM and n-heptane is used in Step 1. This allows for better control of impurities in the starting materials for subsequent steps. Increasing the purity of the starting material, Compound 2-42, also reduces the number of by-products generated in Step 2. The reduction in by-products allows a simpler mixture of products generated in Step 2 to be used in Step 3 without further purification. After overall Boc deprotection, the crude reaction mixture formed after Step 2 proceeds to the single target compound 2. Deprotecting the Boc group using basic conditions instead of more common acidic conditions means that a subsequent step of salt removal is unnecessary, in contrast to the method in Example 12. Crystallization of the neutral amine of Compound 2 yields a material ready for coupling with phosphoramide.

[0325] An alternative method also involves separately preparing the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate. The dihydrokinin base is prepared from the hemisulfate of kinin in a separate reaction, rather than in situ debenzylation of the phosphoramidate. The separate reaction provides greater control over the purity of the final isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate dihydrokinin salt.

[0326] Furthermore, it was found that using COMU as an alternative activator to HATU resulted in higher diastereoselectivity at lower reaction temperatures in the coupling reaction between compound 2 and the dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate. This helps to shorten the reaction time while also resulting in a higher yield of compound 1.

[0327] Part A. Synthesis of Compound 2 The synthesis of intermediate compounds 2-40 is carried out using the same conditions as described in Example 12.

[0328] Step 1: Preparation of Compound 2-42 [ka]

[0329] In a 5 L three-necked glass reactor equipped with a mechanical stirrer, an addition funnel, and a thermometer, tert-butanol (10 vols) was added at 25°C, followed by potassium t-butoxide (3 equivalents). The mixture was stirred for 15 minutes to obtain a nearly clear solution, after which the temperature rose to 35°C due to an exothermic dissolution process. 2-amino-6-chloropurine compound 2-41 (3.1 equivalents) was added all at once to obtain a suspension. The mixture was heated to 52.5°C ± 2.5°C over 30 minutes and stirred at that temperature for 1 hour to obtain a viscous suspension. Acetonitrile (15.0 vols) was added all at once, followed by compound 2-40 (1.0 equivalent), and the mixture was stirred at 52.5°C ± 2.5°C for 16 hours. After the reaction was complete, the mixture was cooled to 5°C ± 5°C, water (8 vols) was added with stirring to obtain a clear solution, then toluene (8 vols) was added and stirred for 2 to 3 minutes. Once the layers settled, the upper organic phase was separated, washed with water (8 vol.), and concentrated under vacuum at 55°C ± 5°C. The residue was then combined and concentrated with toluene (2 × 2 vol.) at 55°C ± 5°C under vacuum, and then mixed with CH2Cl2 (5 vol.) at 20°C ± 5°C to obtain a light-colored suspension. Silica gel (200-300 mesh, 0.3 wt) was added, and the mixture was stirred for 30 minutes. The suspension was filtered through a short silica gel pad (200-300 mesh, 0.7 wt, 8 cm in diameter and 12 cm in height). The moistened silica pad was washed with CH2Cl2 (6 × 1.0 vol.). The combined filtrate was concentrated under vacuum at 55°C for 50 minutes to obtain an oily solid, which was further purified by recrystallization with CH2Cl2 (1.5 vol.) and n-heptane (8 vol.). The solid was collected by filtration through a Buchner funnel and dried in hot air at 60°C ± 5°C for 16 hours to obtain compound 2-42 in 59% yield (mol basis) and 99.5% (a / a) HPLC purity.

[0330] Steps 2 and 3: Preparation of Compounds 2-43 and Telescoping to Compound 2 [ka]

[0331] Here, the procedure of Example 12 was further developed to obtain both compound 2-42 and compound 2-43 as crystallizable solids, which allowed for better control of impurities in these steps through product isolation and purification. However, only compound 2-42 was isolated as a crystalline intermediate, while compound 2-43 obtained from compound 2-42 was not isolated but telescoped to the next step. In this way, problems arising from the presence of impurity compound 2-43B were avoided. Furthermore, by using an aqueous methylamine solution (28% (wt / wt), 3 equivalents) in ACN (10 vol) at 30°C to 40°C, better conditions for step 2 were established for the reaction, and this was post-treated with toluene. As a result, the quality of crude compound 2-43 was greatly improved, allowing it to be used directly in step 3.

[0332] Compound 2-42 (300 g, 1.0 equivalent) was added to a 2 L three-necked glass reactor equipped with a mechanical stirrer, an addition funnel, and a thermometer at 20 °C ± 5 °C, followed by acetonitrile (1500 mL, 5 volumes), and then a methylamine aqueous solution (calculated as 28 wt%, 3.0 equivalents) was added all at once at 25 °C. After the addition, the internal temperature of the reaction system decreased to approximately 20 °C. The reaction system was heated and maintained at 35 °C ± 5 °C and stirred for approximately 16 hours (overnight). The reaction was initially monitored by TLC, which indicated that the reaction was complete. HPLC revealed 95.9% (a / a) of compound 2-43 and 3.6% (a / a) of compound 2-43B. The reaction mixture was concentrated to approximately 1.5 volumes (450 mL) under vacuum (0.1 MPa) at 45 °C to 50 °C. Toluene (1500 mL, 5 volumes) and water (600 mL, 2 volumes) were added at 20°C ± 5°C, and the mixture was stirred for 30 minutes. After standing for 30 minutes, the phases were separated. Water (600 mL, 2 volumes) was added to the organic layer at 20°C ± 5°C, and the mixture was stirred for 30 minutes. After standing for 30 minutes, the layers were separated. This procedure (i.e., layer separation following the addition of water (600 mL, 2 volumes)) was repeated once more. The upper organic phase was concentrated under vacuum to approximately 2 volumes (600 mL). Methanol (600 mL, 2 volumes) was added, and the mixture was concentrated under vacuum to approximately 2 volumes. The resulting mixture was used directly in the next step.

[0333] Methanol (1500 mL, 5 volumes) was added to the above compound 2-43 solution at 20°C ± 5°C. DBU (8.85 g, 0.1 equivalent) was added all at once at 20°C ± 5°C, and the mixture was heated to 60°C-70°C and stirred overnight under reflux. TLC indicated that the reaction was complete, and HPLC analysis showed 99.5% (a / a) of compound 2. Acetonitrile (1800 mL, 6 volumes) was added over 30 minutes via an addition funnel, and the mixture was concentrated to approximately 2 volumes (600 mL) at atmospheric pressure. At this point, the temperature of the distillate reached 80°C. The second portion of acetonitrile (900 mL, 3 volumes) was added over 10 minutes via an addition funnel, and the mixture was concentrated to approximately 3 volumes (900 mL) at atmospheric pressure, at which point the temperature of the distillate reached 82°C. The mixture was stirred at 80°C ± 5°C for approximately 1 hour, then slowly cooled to 20°C to 25°C over 2 hours at a cooling rate of approximately 15°C per 30 minutes. It was further cooled to 5°C ± 5°C over 1 hour and stirred at 5°C ± 5°C for 1 hour. The solid was collected by filtration, and the filtered cake was rinsed with acetonitrile to obtain the wet product. The wet cake was dried in vacuum at 55°C to 60°C for 16 hours to obtain compound 2 as an off-white solid (164.9 g) with a purity of 99.8% (a / a) in a yield of 90.8%. The isolated solid was ground and used in step 7.

[0334] Part B: Synthesis of dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate Step 4: Preparation of compounds 1-5 [ka]

[0335] Isopropyl acetate (10.3 volume) was added to a 50 L four-necked glass reactor equipped with a mechanical stirrer, an addition funnel, and a thermometer. While maintaining the solution temperature below 10°C, phenyl dichlorophosphate (3.5 kg, 1.0 equivalent) was added to the reactor and stirred to obtain a clear solution. The solution was cooled to -10°C ± 5°C, and a solution of benzyl alcohol (1.05 equivalents) and triethylamine (1.2 equivalents) in isopropyl acetate (1.0 volume) was added over 2 hours under nitrogen protection. The mixture was stirred at -10°C ± 5°C for 1.5 hours. Once IPC indicated that the benzyl alcohol had been completely consumed, L-alanine isopropyl hydrochloride (1.0 equivalent) was added to the reactor. Then, an additional solution of triethylamine (2.1 equivalents) in isopropyl acetate (1.0 volume) was added over approximately 2 hours at -10°C ± 5°C under nitrogen protection. The mixture was stirred for a further 1 to 2 hours at -10°C ± 5°C, and the progress of the reaction was monitored by IPC. Once intermediate compounds 1-3 were completely consumed, the reaction mixture was filtered, and the filtered cake was washed with isopropyl acetate (0.66 vol). The filtrate was cooled to below 10°C and washed continuously at below 10°C with water (4.3 vol), aqueous hydrochloric acid (1N, 4.3 vol), saturated aqueous sodium bicarbonate (4.3 vol), and water (4.3 vol). This was then stirred with charcoal (10 wt%) at 25°C to 30°C for 2 hours and filtered. The cake was washed with isopropyl acetate (0.66 vol), and the combined filtrate was concentrated at 40°C to 50°C under a vacuum of less than 0.09 MPa to obtain the crude product compounds 1-5 (6.19 kg) as a pale yellow oil in 99% yield with 90% (a / a) HPLC purity. The product was used directly in step 6.

[0336] Step 5: Preparation of dihydroquinine [ka]

[0337] In a 1 L three-necked glass flask equipped with a mechanical stirrer, an addition funnel, a condenser, and a thermometer, methanol (6 vols) and water (1 vols) were added and stirred. Kinin hemisulfate monohydrate (100 g, 1 equivalent) and Na2CO3 (15 g, 0.55 equivalents) were added to the reactor. The mixture was heated to 50°C-60°C and stirred at 50°C-60°C for 4-5 hours. The mixture was then filtered at high temperature and washed with methanol (0.6 vols). The filtrate was placed in a 1 L one-necked glass flask and 5% wet Pd / C (65% water (by KF), 12% wet weight) was added. Hydrogenation was carried out under hydrogen at 1 atm at 20°C-25°C for 10-15 hours. Once IPC indicated that the kinin had been completely consumed, the mixture was filtered through a Buchner funnel and the filtration cake was rinsed with methanol (0.6 vols). The filtrate was concentrated at 50°C to 60°C under a vacuum of less than 0.09 MPa to obtain the crude product as a mixture of oil and water. The crude product was added to 5% aqueous sodium chloride solution (2 volumes) and DCM (5 volumes) and stirred at 20°C to 30°C for 20 minutes. After settling for 15 minutes, the phases were separated, and the upper aqueous phase was extracted with an additional DCM (1 volume). The organic phases were combined and concentrated to one-quarter of the original volume at 45°C ± 5°C under a vacuum (less than 0.07 MPa), after which n-heptane (3 volumes) was slowly added. The mixture was then concentrated to half its volume at 45°C ± 5°C under a vacuum (less than 0.07 MPa). During concentration, the substance began to precipitate, so n-heptane (3 volumes) was slowly added and stirred at 0°C to 10°C for 5 hours. The solid was collected by filtration and washed with n-heptane (1 volume) to obtain a moist cake, which was dried under vacuum at 45°C ± 5°C for 16 hours to obtain dihydrokinin (79 g) in 95% yield and 97.7% (a / a) HPLC purity.

[0338] Step 6: Preparation of dihydrokinin salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate [ka]

[0339] Isopropanol (356 mL, 5.5 vol) was placed in a 1000 mL three-necked glass flask. Compound 1-5 (64 g, 1.0 equivalent) and dihydroquinine (50 g, 0.9 equivalent) were added and stirred to obtain a clear solution. 5% wet Pd / C (60% water (by KF), 5% (weight / weight) dry basis) was added to this solution, and hydrolysis was carried out at 20°C-25°C for 18-20 hours using hydrogen at 1 atm. Once IPC-1 indicated that compound 1-5 had been completely consumed, the mixture was filtered through a Buchner funnel, and the filtrate was stirred with 4.0 g of charcoal at 25°C-30°C for 2 hours. The mixture was filtered, and the cake was washed with isopropanol (50 mL, 0.8 vol). The filtrate was concentrated at 50°C-60°C under a vacuum of less than 0.09 MPa to obtain the crude product. Isopropyl acetate (230 mL, 3.6 vol.) was added, and the mixture was concentrated again at 50°C to 60°C under a vacuum of less than 0.09 MPa. This process was repeated one more time with 3.6 vol. fresh isopropyl acetate. To the residue, fresh isopropyl acetate (184 mL, 2.9 vol.) was added, and the mixture was stirred at 80°C to 90°C for 2 to 3 hours to obtain a clear solution. This was then cooled to 0°C to 10°C at a cooling rate of 20°C per hour, and stirred at this temperature for 2 to 3 hours. The solid was collected by filtration and rinsed with cold isopropyl acetate (22 mL, 0.3 vol.) to obtain a moist cake (80 g) of crude dihydroquinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate, which was divided into two equal parts.

[0340] The first portion was dried at 50°C for 18 hours without vacuum to obtain 36 g of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate dihydroquinine salt as an off-white solid in 76% yield with a purity of 95.85% (a / a) of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate. The second portion was mixed with isopropyl acetate (80 mL) and stirred at 80°C to 90°C for 2 to 3 hours until completely dissolved. This was then cooled to 0°C to 10°C at a cooling rate of 20°C per hour and stirred at this temperature for 2 to 3 hours. The precipitated solid was filtered, washed with cold isopropyl acetate (11 mL), and dried at 50°C for 18 to 20 hours without vacuum to obtain 33.5 g of dihydrokinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate as a white solid in 71% yield with a purity of 98.65% (a / a) of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate.

[0341] Part C: Synthesis of Compound 1 and Compound 1-A Step 7: Preparation of Compound 1 [ka]

[0342] A thermometer, an addition funnel, and a mechanical stirrer were attached to a 3 L three-necked glass flask. Dichloromethane (10 vol), 2-MeTHF (20 vol), dihydroquinine salt of isopropyl(hydroxy(phenoxy)phosphoryl)-L-alaninate (1.75 equivalents), compound 2 (60 g, 1.0 equivalent), and COMU (1.75 equivalents) were added to the reactor at 20°C under a nitrogen atmosphere. The resulting suspension was heated to approximately 30°C, and DIPEA was slowly added to the reaction mixture via the addition funnel at 30°C ± 2.5°C over 3 hours. The reaction mixture was stirred at 30°C ± 2.5°C for 2 hours and considered complete by IPC test. The mixture was cooled to 0°C to 10°C over 1 hour and washed with water (10 vol). When an aqueous hydrochloric acid solution (20% (wt / wt), 300 g, 8.5 equivalents) was slowly added over 1 hour at -5°C to 0°C while stirring, most of the dihydroquinine hydrochloride (DHQ·HCl) precipitated. The salt was removed by filtration, and the filtrate was washed with an aqueous HCl solution (7% (wt / wt), 180 g, 2.0 equivalents) at 0°C to 10°C to remove all remaining DHQ, compound 2, DIPEA, and urea by-products. This was then washed with a 5% aqueous sodium bicarbonate solution (3 × 1.9 equivalents) to remove oxime by-products, followed by washing with water (2 × 10 volumes). Charcoal (10% (wt / wt)) was added to the organic layer, stirred at 20°C to 30°C for 2 hours, filtered, and the cake was washed with dichloromethane (0.5 volume). The filtrate was then concentrated to approximately 5 volumes at 30°C to 55°C under a vacuum of less than 0.09 MPa. Toluene (600 mL, 10 volumes) was added to the mixture and concentrated again to approximately 5 volumes at 40°C to 55°C under a vacuum of less than 0.09 MPa. Ethyl acetate (120 mL, 2 volumes) and further toluene (180 mL, 3 volumes) were added to the residue, and the mixture was heated to 65°C to 75°C with stirring to obtain a clear solution. This was cooled stepwise with stirring, first to 50°C over 1 hour, then to 30°C over 1 hour, and finally to 5°C over another 1 hour. After continuing stirring at 5°C for a further 4 hours, the solid was collected by filtration to obtain crude compound 1 as a yellow solid.

[0343] Crude compound 1 was divided into two equal parts. Part 1 was further purified by two consecutive recrystallizations from ethyl acetate / toluene (1:1 (volt / volt), 5.0 volt) and ethyl acetate (5.0 volt), while Part 2 was purified by two consecutive recrystallizations from ethyl acetate (5.0 volt). In each case, compound 1 was obtained with a purity of over 99.6% (a / a) and isomer impurities C of less than 0.20% (a / a), as determined by HPLC. The molar yield for step 7 was approximately 55%.

[0344] Step 8: Preparation of Compound 1-A [ka]

[0345] [Table 1]

[0346] A 500 mL four-necked jacketed flask equipped with a mechanical stirrer, addition funnel, condenser, and thermometer was filled with acetone (12 volumes) at an external temperature of 15°C to 30°C. Compound 1 (30 g, 92% (weight / weight) (HPLC and titration assay)) was added to the reactor and stirred. The temperature of the solution in the reactor was controlled to 20°C to 25°C. Visual inspection confirmed that the reactants were a clear solution. While maintaining the internal temperature at 20°C to 25°C, concentrated sulfuric acid (the amount varied as shown in the materials table above for three separate experiments using 30 g of Compound 1 each) was slowly added to the reactor over 2 hours. The suspension was stirred for 30 minutes at the same internal temperature of 20°C to 25°C, then heated to 40°C to 50°C and stirred at this temperature for 16 hours. This was then cooled to an internal temperature of 20°C to 25°C over 4 hours and stirred for at least 2 hours. The solid was collected by filtration, and the moist filtration cake was washed with acetone (1 volume) at 15°C–20°C. The product was dried in an air oven at 40°C ± 5°C for at least 2 hours, followed by further drying in an air oven at 55°C ± 5°C for approximately 18 hours. Three batches of compound 1-A obtained using three different equivalents of sulfuric acid under this procedure had a purity of over 99.95% (a / a) according to HPLC. A summary of the yields and analytical data for these batches is shown in Table 2.

[0347] [Table 2]

[0348] Example 14: XPRD data for selected compound 1-A sample

[0349] [Table 3]

[0350] [Table 4]

[0351] [Table 5]

[0352] Example 15: Differential scanning calorimetry data for selected compound 1-A sample Compound 1-A from Experiment 1: Processing software: METTLER TOLEDO STARe 15.00 Sample: Compound 1-A from Experiment 1, 2.7560 mg Sample holder: Aluminum standard 40 μL; Weight: 0; Material: Aluminum Method: 80~200°C 10K N2 50; dt 1.00s; [1] 80.0℃~200.0℃, 10.00K / min, N2 50.0ml / min; Synchronization effective.

[0353] The DSC thermogram showed an endothermic peak with an onset at 121.71°C, a peak at 133.70°C, and an endset at 141.02°C, with an integral value of -26.34 mJ. The thermogram of this sample is shown in Figure 4.

[0354] Compound 1-A from Experiment 2: Processing software: METTLER TOLEDO STARe 15.00 Sample: Compound 1-A from Experiment 2, 2.0660 mg Sample holder: Aluminum standard 40 μL; Weight: 0; Material: Aluminum Method: 80~200°C 10K N2 50; dt 1.00s; [1] 80.0℃~200.0℃, 10.00K / min, N2 50.0ml / min; Synchronization effective.

[0355] The DSC thermogram showed two endothermic peaks. The first peak had an onset at 122.35°C, a peak at 133.55°C, an endset at 140.41°C, and an integral value of -14.97 mJ. The second peak had an onset at 174.19°C, a peak at 174.57°C, an endset at 176.18°C, and an integral value of -0.43 mJ. The thermogram of this sample is shown in Figure 5.

[0356] Compound 1-A from Experiment 3: Processing software: METTLER TOLEDO STARe 15.00 Sample: Compound 1-A from Experiment 3, 1.9360 mg Sample holder: Aluminum standard 40 μL; Weight: 0; Material: Aluminum Method: 80~200°C 10K N2 50; dt 1.00s; [1] 80.0℃~200.0℃, 10.00K / min, N2 50.0ml / min; Synchronization effective.

[0357] The DSC thermogram showed an endothermic peak with an onset at 129.41°C, a peak at 134.55°C, and an endset at 141.56°C, with an integral value of -13.10 mJ. The thermogram of this sample is shown in Figure 6.

[0358] This specification is written with reference to embodiments of the present invention. However, it will be understood by those skilled in the art that various modifications and changes can be made without departing from the scope of the invention as described in the appended claims. Accordingly, this specification is intended to be illustrative rather than restrictive, and all such modifications are intended to be within the scope of the invention. Item 1 The nucleotide of formula XVI is the S of the diastereomer of formula XVI, which has a purity of over 90%. p - A method for preparing phosphoramidate nucleotides, (a) Contacting nucleoside compound 2 with the dihydrokinine salt of the compound of formula XVII, as well as an activator and a base, to form the diastereomer S of formula XVI. p - The process of obtaining phosphoramidate nucleotides, [ka] (b) Optionally, the diastereomerized S of formula XVI p - A process to further purify phosphoramidate nucleotides to increase their purity, Including, in the formula, R 4 is hydrogen, C 1~6 Alkyl, C 3~7 It is a cycloalkyl or aryl compound. R5 is hydrogen or C 1~6 It is alkyl, R 6a and R 6b These are, independently, hydrogen and C 1~6 Alkyl and C 3~7 Selected from the group consisting of cycloalkyl, R 7 is hydrogen, C 1~6 Alkyl, C 1~6 Haloalkyl, or C 3~7 It is a cycloalkyl, method. Section 2 R 4 The method described in item 1, wherein the aryl is... Section 3 R 5 The method according to item 1 or 2, wherein is hydrogen. Section 4 R 6a and R 6b The method according to any one of items 1 to 3, wherein at least one of is hydrogen. Section 5 R 6a and R 6b The method according to any one of claims 1 to 4, wherein is hydrogen and methyl. Section 6 R 7 C 1~6 The method according to any one of items 1 to 5, wherein the alkyl group is used. Section 7 The aforementioned activators are HOBt (1-hydroxybenzotriazole), PyBOP (benzotriazole-1-yloxytri(pyrrolidino)phosphonium hexafluorophosphate), HATU (O-(7-azabenzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate), HBTU (3-[bis(dimethylamino)methylumyl]-3H-benzotriazole-1-oxidehexafluorophosphate), HCTU (2 The method according to any one of claims 1 to 6, selected from (6-chloro-1H-benzotriazol-1-yl)-1,1,3,3-tetramethylaminium hexafluorophosphate), COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate), and TBTU (O-benzotriazol-1-yl-1,1,3,3-tetramethyluronium tetrafluoroborate). Item 8 The method according to any one of claims 1 to 7, wherein the activator is HATU(O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate). Section 9 The method according to any one of claims 1 to 7, wherein the activator is COMU((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate). Item 10 The aforementioned base is NR 3 The method according to any one of claims 1 to 9, wherein R can be independently selected from H, alkyl, aryl, heteroaryl, alkenyl, alkynyl, benzyl, and allyl, where at least one R is not hydrogen. Section 11 The aforementioned base is DIPEA (N,N-diisopropylethylamine) or NET 3 The method according to any one of claims 1 to 10, wherein (triethylamine). Section 12 The method according to any one of claims 1 to 11, wherein the base is DIPEA (N,N-diisopropylethylamine). Section 13 The method according to any one of items 1 to 9, wherein the base is a kinin. Item 14 Step (a) is the method according to any one of items 1 to 13, carried out in a polar aprotic solvent. Section 15 The method according to claim 13, wherein the solvent is selected from dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate (SiO), acetonitrile (MeCN), dimethyl sulfoxide (DMSO), acetone, and N-methylpyrrolidone. Section 16 The method according to any one of claims 1 to 13, wherein step (a) is carried out in a mixture of solvents selected from dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate (SiO), acetonitrile (MeCN), dimethyl sulfoxide (DMSO), acetone, and N-methylpyrrolidone. Item 17 The method according to claim 16, wherein the solvent mixture comprises dichloromethane (DCM) and 2-methyltetrahydrofuran (2-MeTHF). Section 18 S before process (b) p Diastereomer:R p The method according to any one of items 1 to 17, wherein the diastereomer ratio is approximately 60:40. Section 19 S before process (b) p Diastereomer:R p The method according to any one of items 1 to 18, wherein the diastereomer ratio is approximately 70:30. Section 20 S before process (b) p Diastereomer:R p The method according to any one of items 1 to 19, wherein the diastereomer ratio is greater than approximately 80:20. Section 21 S before process (b) p Diastereomer:R p The method according to any one of items 1 to 20, wherein the diastereomer ratio is greater than 90:10. Section 22 The nucleotide of formula XVI is the method according to any one of items 1 to 21, wherein the nucleotide is of a purity of more than approximately 98%. Section 23 The nucleotide of formula XVI is of a purity of more than approximately 99%, as described in any one of items 1 to 22. Section 24 The purification in step (b) is selective crystallization, as described in any one of items 1 to 23. Section 25 The crystallization is carried out in a polar organic solvent, as described in item 24. Section 26 The crystallization is carried out in an alkyl ester, as described in item 24 or 25. Section 27 The crystallization is carried out in ethyl acetate or isopropyl acetate, according to any one of claims 24 to 26. Section 28 The crystallization is carried out in a mixture of solvents, according to the method of item 24. Section 29 The crystallization is carried out in a mixture of a polar organic solvent and an aromatic solvent, as described in item 24 or 28. Item 30 The crystallization is carried out in a mixture of ethyl acetate and toluene, according to the method of any one of claims 24, 28, or 29. Item 31 (c) The method according to any one of claims 1 to 30, further comprising the step of converting the compound of formula XVI into a pharmaceutically acceptable salt. Section 32 The method according to item 31, wherein the pharmaceutically acceptable salt is a hemisulfate. Item 33 The compound of formula XVI is

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Claims

1. S of the diastereomer of formula XVI having a purity of more than 90% ｐ - A method for preparing phosphoramidate nucleotides, (a) The nucleoside compound 2 and the dihydrokinine salt of the compound of formula XVIi are brought into contact in the presence of an activator selected from HATU (O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) and COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate) and a base to form the diastereomer of formula XVI. ｐ - The process of obtaining phosphoramidate nucleotides, 【Chemistry 1】 (b) The diastereomer-enriched S of formula XVI ｐ - A process to further purify the phosphoramidate nucleotide to increase its purity, Including, in the formula, R ４ It is phenyl, R ５ It is hydrogen, R6a is hydrogen, R 6b is methyl, R ７ It is isopropyl. method.

2. The method according to claim 1, wherein the activator is COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate).

3. The method according to claim 1, wherein the activator is HATU(O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate).

4. The method according to claim 1, wherein the base is DIPEA (N,N-diisopropylethylamine).

5. The method according to claim 1, wherein step (a) is carried out in a polar aprotic solvent.

6. The method according to claim 5, wherein the solvent is selected from dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), ethyl acetate (EtOAc), acetonitrile (MeCN), dimethyl sulfoxide (DMSO), acetone, and N-methylpyrrolidone.

7. The method according to claim 1, wherein step (a) is carried out in a mixture of solvents selected from dimethylformamide (DMF), dichloromethane (DCM), tetrahydrofuran (THF), ethyl acetate (EtOAc), acetonitrile (MeCN), dimethyl sulfoxide (DMSO), acetone, and N-methylpyrrolidone.

8. The method according to claim 1, wherein step (a) is carried out in a polar aprotic solvent containing dichloromethane (DCM).

9. The aforementioned base is of formula NR ３ The method according to claim 1, wherein R is a base, and R can be independently selected from H, alkyl, aryl, heteroaryl, alkenyl, alkynyl, benzyl, and allyl, where at least one R is not hydrogen.

10. The activator is COMU ((1-cyano-2-ethoxy-2-oxoethylideneaminooxy)dimethylamino-morpholino-carbenium hexafluorophosphate), The method according to claim 1, wherein the base is DIPEA (N,N-diisopropylethylamine).

11. The method according to claim 10, wherein step (a) is carried out in a polar aprotic solvent containing dichloromethane.

12. The activator is HATU (O-(7-azabenzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate), The aforementioned base is DIPEA (N,N-diisopropylethylamine). The method according to claim 1.

13. The method according to claim 1, wherein step (a) is carried out in a polar aprotic solvent.

14. The method according to claim 13, wherein the polar aprotic solvent is dichloromethane.

15. S before step (b) ｐ Diastereomer: R ｐ The method according to claim 1, wherein the ratio of the diastereomers is more than 60:

40.

16. S before process (b) ｐ Diastereomer: R ｐ The method according to claim 1, wherein the ratio of diastereomers is greater than 70:

30.

17. S before process (b) ｐ Diastereomer: R ｐ The method according to claim 1, wherein the ratio of diastereomers is greater than 80:

20.

18. S before process (b) ｐ Diastereomer: R ｐ The method according to claim 1, wherein the ratio of diastereomers is greater than 90:

10.

19. The method according to claim 1, wherein the purification in step (b) is selective crystallization.

20. The method according to claim 19, wherein the crystallization is carried out in a polar organic solvent.

21. The method according to claim 20, wherein the crystallization is carried out in an alkyl ester.

22. The method according to claim 21, wherein the crystallization is carried out in ethyl acetate or isopropyl acetate.

23. The method according to claim 19, wherein the crystallization is carried out in a mixture of solvents selected from alkyl acetate solvents, chlorinated solvents, and ketone solvents.

24. The method according to claim 23, wherein the crystallization is carried out in an organic solvent selected from C1-8 alcohols, C2-8 ethers, C3-7 ketones, C3-7 esters, C1-2 chlorocarbons, and C2-7 nitriles, and a poor solvent selected from C5-12 saturated hydrocarbons, C6-12 aromatic hydrocarbons, and petroleum ethers.

25. The method according to claim 24, wherein the crystallization is carried out in a mixture of C3-7 esters and C6-12 aromatic hydrocarbons.

26. (c) The method according to claim 1, further comprising the step of converting compound 1 to a pharmaceutically acceptable salt.

27. The method according to claim 26, wherein the pharmaceutically acceptable salt is a hemisulfate.

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