Nucleotide-lipid conjugate and use thereof

Abstract

The present invention relates to a nucleotide-lipid conjugate and use thereof, and also relates to an oligonucleotide comprising the nucleotide-lipid conjugate. The oligonucleotide can be effectively delivered to extrahepatic tissues to inhibit gene expression.

Description

Nucleotide-lipid conjugates and their applications

[0001] This application is based on and claims priority to CN application No. 202510361057.2 filed on March 25, 2025 and CN application No. 202610162100.7 filed on February 4, 2026, the disclosures of the aforementioned applications are incorporated herein by reference in their entirety. Technical Field

[0002] This invention belongs to the field of biomedical technology, specifically relating to a nucleotide-lipid conjugate and its applications. Background Technology

[0003] Oligonucleotide drugs are a class of drugs composed of short nucleotide sequences that can provide patients with more effective treatment options. For example, antisense oligonucleotides (ASO) and small interfering RNA (siRNA) can interfere with the transcription and translation of disease-causing genes by recognizing and binding to target nucleotide sequences.

[0004] However, oligonucleotide drugs still face many challenges, such as efficient delivery. How to effectively deliver siRNA to extrahepatic tissues is a key focus and challenge in siRNA drug development. More efficient and stable delivery systems can help achieve selective delivery of siRNA drugs to extrahepatic cells, increasing the therapeutic window and thus improving efficacy while ensuring safety. Summary of the Invention

[0005] This invention provides a lipophilic nucleotide analog that effectively delivers siRNA to extrahepatic tissues by binding nucleotides to lipids, thereby enhancing the delivery efficiency of siRNA.

[0006] Nucleotide-lipid conjugate monomers

[0007] A first aspect of the present invention provides a nucleotide-lipid conjugate monomer or a pharmaceutically acceptable salt thereof, a tautomer, an enantiomer, or a stereoisomer, wherein the nucleotide-lipid conjugate monomer comprises the structure shown in formula (I).

[0008] in,

[0009] Z 1 Z 2 Z 3 Z 4 Each of them is independently selected from -O-, -S-, and -N(R). a )-, -C(=O)-, -OC(=O)-, -C(=O)O-, -OC(=O)NR a -、-C(=O)NR a-、-C(=O)NR a NR a C(=O)-、-NR a C(=O)O-、-NR a C(=O)-、-NR a C(=O)NR a -、-OC 1-6 Alkylene-, -NR a C 1-6 Alkylene-, -OC(=O)NR a C 1-6 Alkylene-, -NR a C(=O)OC 1-6 Alkylene-, -NR a C(=O)C 1-6 Alkylene-,-C(=O)NR a C 1-6 Alkylene-, -NR a C(=O)NR a C 1-6 Alkylene -, -(CH2OCH2) t -、-C 1-6 Alkylene (CH2OCH2) t -、-(CH2OCH2) t C 1-6 alkylene-, -C 1-6 Alkylene (CH2OCH2) t C 1-6 Alkylene-,-C(=O)NR a -C 1-6 Alkylene-NR a -C 1-6 Alkylene-NR a C(=O)-、 C 3-9 Cycloalkylene, 4-9 membered heterocyclic, 5-9 membered heteroarylene, and any combination thereof, or, Z 1 Z 2 Z 3 Z 4 One, two, or three of them are missing;

[0010] R a Each is independently selected from H and C. 1-6 alkyl;

[0011] t can be 0, 1, 2, 3, 4, 5, or 6;

[0012] R 1 Selected from C 12-32 Alkyl, C 12-32 alkenyl and C 12-32alkynyl group, the C 12-32 Alkyl, C 12-32 alkenyl and C 12- 32 The alkynyl group may be optionally surrounded by one or more elements selected from H, halogen, OH, CN, NO2, COOH, -OC. 1-6 Alkyl, -NHC 1- 6-alkyl and -N(C) 1-6 Substitution of alkyl groups;

[0013] The condition is that, Not O.

[0014] In some implementations, Z 1 Z 2 Z 3 Z 4 Each of them is independently selected from -O-, -S-, and -N(R). a )-, -C(=O)-, -OC(=O)-, -C(=O)O-, -OC(=O)NR a -、-C(=O)NR a -、-C(=O)NR a NR a C(=O)-、-NR a C(=O)O-、-NR a C(=O)-、-NR a C(=O)NR a -、-OC 1-6 Alkylene-, -NR a C 1-6 Alkylene-, -OC(=O)NR a C 1-6 Alkylene-, -NR a C(=O)OC 1-6 Alkylene-, -NR a C(=O)C 1-6 Alkylene-,-C(=O)NR a C 1-6 Alkylene-, -NR a C(=O)NR a C 1-6 Alkylene -, -(CH2OCH2) t -、-C 1-6 Alkylene (CH2OCH2) t -、-(CH2OCH2) t C 1-6 alkylene-, -C 1-6 Alkylene (CH2OCH2) t C 1-6 Alkylene-,-C(=O)NRa -C 1-6 Alkylene-NR a -C 1-6 Alkylene-NR a C(=O)-、 C 3-9 Cycloalkylene, 4-9 membered heterocyclic, 5-9 membered heteroarylene, and any combination thereof, or, Z 1 Z 2 Z 3 Z 4 One, two, or three of them are missing;

[0015] R a Each is independently selected from H and C. 1-6 alkyl;

[0016] t can be 0, 1, 2, 3, 4, 5, or 6;

[0017] R 1 Selected from C 12-32 Alkyl, C 12-32 alkenyl and C 12-32 alkynyl group, the C 12-32 Alkyl, C 12-32 alkenyl and C 12- 32 The alkynyl group may be optionally surrounded by one or more elements selected from H, halogen, OH, CN, NO2, COOH, -OC. 1-6 Alkyl, -NHC 1- 6-alkyl and -N(C) 1-6 Substitution of alkyl groups;

[0018] The condition is that, Not O.

[0019] In some implementations, Z 1 Z 2 Z 3 Z 4 Each is independently selected from -O-, -N(R) a -, -C(=O)-, -OC(=O)NR a -、-C(=O)NR a -、-C(=O)NR a NR a C(=O)-、-NR a C(=O)O-、-NR a C(=O)-、-NR a C(=O)NR a -、-OC 1-6 Alkylene-, -NR a C 1-6 Alkylene-, -OC(=O)NRa C 1-4 Alkylene-, -NR a C(=O)OC 1-4 Alkylene-, -NR a C(=O)C 1-4 Alkylene-,-C(=O)NR a C 1-4 Alkylene-, -NR a C(=O)NR a C 1-4 Alkylene -, -(CH2OCH2) t -、-C 1-4 Alkylene (CH2OCH2) t -、-(CH2OCH2) t C 1-4 alkylene-, -C 1-4 Alkylene (CH2OCH2) t C 1-4 Alkylene-,-C(=O)NR a -C 1-4 Alkylene-NR a -C 1-4 Alkylene-NR a C(=O)-、 C 3-6 Cycloalkylene, 4-7 membered heterocyclic alkylene, 5-6 membered heteroaryl alkylene, and any combination thereof, or, Z 1 Z 2 Z 3 Z 4 If 1, 2, or 3 of them are missing, R a And t as defined in any embodiment of the present invention.

[0020] In some implementations, Z 1 Z 2 Z 3 Z 4 Each is independently selected from -O-, -N(R) a )-、-OC(=O)NR a -、-C(=O)NR a -、-C(=O)NR a NR a C(=O)-、-NR a C(=O)O-、-NR a C(=O)-、-NR a C(=O)NR a -、-OC 1- 6-alkylene-, -NR a C 1-6 Alkylene-, -OC(=O)NRa C 1-4 Alkylene-, -NR a C(=O)OC 1-4 Alkylene-, -NR a C(=O)C 1-4 Alkylene-,-C(=O)NR a C 1-4 Alkylene-, -NR a C(=O)NR a C 1-4 Alkylene -, -(CH2OCH2) t -、-C 1-4 Alkylene (CH2OCH2) t -、-(CH2OCH2) t C 1-4 alkylene-, -C 1-4 Alkylene (CH2OCH2) t C 1-4 Alkylene-,-C(=O)NR a -C 1-4 Alkylene-NR a -C 1-4 Alkylene-NR a C(=O)-、 C 3-6 Cycloalkylene, 4-7 membered heterocyclic alkylene, 5-6 membered heteroaryl alkylene, and any combination thereof, or, Z 1 Z 2 Z 3 Z 4 If 1, 2, or 3 of them are missing, R a And t as defined in any embodiment of the present invention.

[0021] In some implementations, Z 1 Z 2 Z 3 Z 4 Each is independently selected from -O- and -NR. a -、-C(=O)-、-NR a C(=O)NR a -、-C(=O)NR a NR a C(=O)-、-O(CH2) m -、-OC(=O)NR a (CH2) n -、-NR a C(=O)(CH2) n -、-NR a C(=O)O(CH2) n-、-C(=O)NR a (CH2) n -、-(CH2) p (CH2OCH2) t (CH2) q -、-C(=O)NR a (CH2) m NR a (CH2) m NR a C(=O)-、 4-6 membered heterocyclic groups, 5-6 membered heteroaryl groups and any combination thereof, or, Z 1 Z 2 Z 3 Z 4 In the given condition, 1, 2, or 3 are not present, where m and t are each independently 1, 2, 3, or 4, and n, p, and q are each independently 0, 1, 2, 3, or 4. R a Each is independently selected from H, methyl, ethyl and isopropyl.

[0022] In some implementations, Z 1 Z 2 Z 3 Z 4 Each is independently selected from -O- and -NR. a C(=O)NR a -、-C(=O)NR a NR a C(=O)-、-O(CH2) m -、-OC(=O)NR a (CH2) n -、-NR a C(=O)(CH2) n -、-NR a C(=O)O(CH2) n -、-C(=O)NR a (CH2) n -、-(CH2) p (CH2OCH2) t (CH2) q -、-C(=O)NR a (CH2) m NR a (CH2) m NR a C(=O)-、 4-6 membered heterocyclic groups, 5-6 membered heteroaryl groups and any combination thereof, or, Z 1 Z 2 Z 3 Z4 In the given condition, 1, 2, or 3 are not present, where m and t are each independently 1, 2, 3, or 4, and n, p, and q are each independently 0, 1, 2, 3, or 4. R a Each is independently selected from H, methyl, ethyl and isopropyl.

[0023] In some implementations, Z 1 It does not exist, or it is selected from -O(CH2). m -、-OC(=O)NR a -、-NR a C(=O)(CH2) n -and-NR a C(=O)O(CH2) n - where m is 1, 2, 3, or 4, n is 0, 1, 2, 3, or 4, and R a Each is independently selected from H and methyl.

[0024] In some implementations, Z 1 It does not exist, or it is selected from -OCH2-, -OCH2CH2-, -OCH2CH2CH2-, -OC(=O)NH-, -NHC(=O)-, -NHC(=O)O-, -NHC(=O)CH2-, -NHC(=O)OCH2CH2- and -NHC(=O)CH2CH2-.

[0025] In some implementations, Z 1 Selected from -OCH2-*, -OCH2CH2-*, -OCH2CH2CH2-*, -OC(=O)NH-*, -NHC(=O)-*, -NHC(=O)O-*, -NHC(=O)CH2-*, -NHC(=O)OCH2CH2-*, and -NHC(=O)CH2CH2-*, where the * terminator is related to Z. 2 Connected.

[0026] In some implementations, Z 1 It does not exist, or it is selected from -OCH2-, -OCH2CH2-, -OCH2CH2CH2-, -OC(=O)NH-, -NHC(=O)O-, -NHC(=O)CH2-, -NHC(=O)OCH2CH2- and -NHC(=O)CH2CH2-.

[0027] In some implementations, Z 1Selected from -OCH2-*, -OCH2CH2-*, -OCH2CH2CH2-*, -OC(=O)NH-*, -NHC(=O)O-*, -NHC(=O)CH2-*, -NHC(=O)OCH2CH2-*, and -NHC(=O)CH2CH2-*, where the * terminator is related to Z. 2 Connected.

[0028] In some implementations, Z 1 It does not exist.

[0029] In some implementations, Z 2 It does not exist, or it is selected from -C(=O)NR a (CH2) n -、-NR a C(=O)NR a -、-C(=O)NR a NR a C(=O)- and -(CH2) p (CH2OCH2) t (CH2) q - where n is 0, 1, 2, or 3, p is 0, 1, or 2, q is 0, 1, or 2, t is 1, 2, or 3, and R a Each is independently selected from H and methyl.

[0030] In some implementations, Z 2 It does not exist, or it is selected from -C(=O)NH-, -C(=O)NHCH2-, -C(=O)NHNHC(=O)-, -NHC(=O)NH-, -CH2OCH2-, -CH2(CH2OCH2)2-, -(CH2OCH2)2CH2- and -CH2(CH2OCH2)2CH2-.

[0031] In some implementations, Z 2 Selected from -C(=O)NH-*, -C(=O)NHCH2-*, -NHC(=O)NH-*, -CH2OCH2-*, -CH2(CH2OCH2)2-*, -(CH2OCH2)2CH2-*, and -CH2(CH2OCH2)2CH2-*, wherein the * terminus is related to Z. 3 Connected.

[0032] In some implementations, Z 2 It does not exist.

[0033] In some implementations, Z 3 It does not exist, or is selected from 5-6-membered heteroaryl and 4-6-membered heterocyclic groups, wherein the 5-6-membered heteroaryl and 4-6-membered heterocyclic groups contain 1, 2, 3 or 4 N atoms.

[0034] In some implementations, Z 3 It does not exist, or it is selected from pyridine, pyrazolidine, imidazolyl, triazolidine, isoxazolidine, oxazolidine, pyridinidine, pyridazinidine, pyrazinidine, zazacyclobutyl, pyridinealkyl, piperidinidine, piperazinidine, high piperidinidine, and morpholino.

[0035] In some implementations, Z 3 Does not exist, or selected from Pyridine, isoxazolyl, pyridinyl, pyrazinyl, pyridinealkyl, piperidinyl, and piperazinyl.

[0036] In some implementations, Z 3 Selected from Among them, * end and Z 4 Connected.

[0037] In some implementations, Z 3 It does not exist, or it is selected from pyridine, pyrazolidine, imidazolyl, triazolidine, aziridine, pyridinealkyl, piperidinyl, piperazinyl, periperazinyl, and morpholinyl.

[0038] In some implementations, Z 3 Does not exist, or selected from Piperidine and piperazine.

[0039] In some implementations, Z 3 Selected from Among them, *end and Z 4 Connected.

[0040] In some implementations, Z 3 It does not exist.

[0041] In some implementations, Z 4 Does not exist, or is selected from -O- or -NR a -、-C(=O)-、-C(=O)NR a -、-NR a C(=O)-、 and -C(=O)NR a (CH2) m NR a (CH2) m NR a C(=O)-, where m is 1, 2, 3 or 4, R a Each is independently selected from H and methyl.

[0042] In some implementations, Z 4 It does not exist, or is selected from -O-, -NH-, -C(=O)-, -C(=O)NH-, -NHC(=O)-,

[0043] In some implementations, Z 4 Selected from -O-*, -NH-*, -C(=O)-*, -C(=O)NH-*, -NHC(=O)-*, Among them, * end and R 1 Connected.

[0044] In some implementations, Z 4 It does not exist, or it is selected from -O-, -C(=O)NR a -、-NR a C(=O)-、 and -C(=O)NR a (CH2) m NR a (CH2) m NR a C(=O)-, where m is 1, 2, 3 or 4, R a Each is independently selected from H and methyl.

[0045] In some implementations, Z 4 It does not exist, or it is selected from -O-, -C(=O)NH-, -NHC(=O)-,

[0046] In some implementations, Z 4 Selected from -O-*, -C(=O)NH-*, -NHC(=O)-*, Among them, * end and R 1 Connected.

[0047] In some implementations, Z 4 It does not exist.

[0048] In some implementations, Selected from Among them, * end and R 1 Connected.

[0049] In some implementations, Selected from Among them, * end and R 1Connected.

[0050] In some implementations,

[0051] -Z 1 -Z 2 - It does not exist, or it is a structure composed of one or more of the following groups (e.g., 1, 2, 3, 4, or 5): -O-, -N(R a )-, -C(=O)-, -OC(=O)-, -C(=O)O-, -C(=O)NR a -、-NR a C(=O)-、-OC(=O)NR a -、-NR a C(=O)O-、-C 1-6 alkylene-, R a Each is independently selected from H and methyl;

[0052] Z 3 Selected from 5-9 membered heteroaryl and 4-9 membered heterocyclic groups;

[0053] Z 4 Does not exist, or is selected from -O- or -NR a -, -C(=O)-, -OC(=O)-, -C(=O)O-, -C(=O)NR a -and-NR a C(=O)-.

[0054] In some implementations, -Z 1 -Z 2 -Does not exist, or selected from -OC 1-6 Alkylene-, -OC 1-6 Alkylene-C(=O)NR a C 1-6 Alkylene-, -NR a C(=O)C 1-6 Alkylene-, -OC(=O)NR a -、-NR a C(=O)O-、-C(=O)NR a -and-NR a C(=O)-,R a Each is independently selected from H and methyl.

[0055] In some implementations, -Z 1 -Z 2 - does not exist, or is selected from -OCH2-, -OCH2-C(=O)NHCH2-, -NHC(=O)CH2, -OC(=O)NH-, -NHC(=O)O- and -NHC(=O)-.

[0056] In some implementations, -Z 1 -Z 2 - Does not exist.

[0057] In some implementations, -Z 1 -Z 2 - Selected from -OCH2-C(=O)NHCH2-, -NHC(=O)CH2, -OC(=O)NH-, -NHC(=O)O- and -NHC(=O)-.

[0058] In some implementations, Z 3 Selected from 5-6 membered heteroaryl and 4-6 membered heterocyclic groups. In some embodiments, Z 3 It is a 5-6 member heteroaryl group.

[0059] In some implementations, Z 3 Selected from triazoleyl, pyridineyl, isoxazolyl, pyridinyl, pyrazinyl, pyridinealkyl, piperidinyl, and piperazinyl. In some embodiments, Z 3 It is a triazole group.

[0060] In some implementations, Z 4 Does not exist, or is selected from -O- or -NR a - and -C(=O)-.

[0061] In some implementations, Z 4 It does not exist.

[0062] In some implementations, Z 4 Selected from -O-, -NH- and -C(=O)-.

[0063] In some implementations, Selected from Among them, * end and R 1 Connected.

[0064] In some implementations, Selected from Among them, * end and R 1 Connected.

[0065] In some implementations, Selected from Among them, * end and R 1 Connected.

[0066] In some implementations, for Among them, * end and R 1 Connected.

[0067] In some implementations, for Among them, * end and R 1 Connected.

[0068] In some implementations, for Among them, * end and R 1 Connected.

[0069] In some implementations,

[0070] Z 1 Selected from -O(CH2) m -、-OC(=O)NR a -、-NR a C(=O)- and -NR a C(=O)O-, where m is 1, 2, 3 or 4, R a Each is independently selected from H and methyl;

[0071] Z 2 Selected from -C(=O)NR a (CH2) n -、-NR a C(=O)NR a - and -(CH2) p (CH2OCH2) t (CH2) q - where n is 0, 1, 2, or 3, p is 0, 1, or 2, q is 0, 1, or 2, t is 1, 2, or 3, and R a Each is independently selected from H and methyl;

[0072] Z 3 It does not exist;

[0073] Z 4 Selected from -O-, -NR a -, -C(=O)-, -OC(=O)-, -C(=O)O-, -C(=O)NR a -and-NR a C(=O)-.

[0074] In some implementations, Z 1 It is -OCH2CH2-.

[0075] In some implementations, Z 1 Selected from -OC(=O)NH-, -NHC(=O)- and -NHC(=O)O-.

[0076] In some implementations, Z 2 Selected from -C(=O)NH- and -(CH2) p (CH2OCH2) t (CH2) q - where p is 0, 1 or 2, q is 0, 1 or 2, and t is 1, 2 or 3.

[0077] In some implementations, Z 2 It is -C(=O)NH-.

[0078] In some implementations, Z 2 Selected from -CH2OCH2-, -CH2(CH2OCH2)2-, -(CH2OCH2)2CH2- and -CH2(CH2OCH2)2CH2-.

[0079] In some implementations, Z 4 Selected from -O-, -C(=O)NH- and -NHC(=O)-.

[0080] In some implementations, for

[0081] In some implementations, Selected from

[0082] In some implementations, R 1 Selected from C 12-28 Alkyl and C 12-28 alkenyl, the C 12-28 Alkyl and C 12-28 The alkenyl group may be optionally substituted by one or more groups selected from H, halogen, OH, CN, COOH, -OCH3, -NHCH3 and -N(CH3)2.

[0083] In some implementations, R 1 Selected from C 14-24 Alkyl, the C 14-24 The alkyl group may be optionally substituted with one or more groups selected from H, halogen, OH, CN, COOH, -OCH3, -NHCH3 and -N(CH3)2.

[0084] In some implementations, R 1 C 15-22 alkyl.

[0085] In some implementations, R 1 Selected from CH2(CH2) 13 CH3, CH2(CH2) 14 CH3, CH2(CH2)15 CH3, CH2(CH2) 16 CH3, CH2(CH2) 17 CH3, CH2(CH2) 18 CH3, CH2(CH2) 19 CH3 and CH2(CH2) 20 CH3.

[0086] In some implementations, R 1 For CH2(CH2) 14 CH3.

[0087] In some implementations, R 1 For CH2(CH2) 19 CH3.

[0088] In some implementations, R 1 For CH2(CH2) 20 CH3.

[0089] In some implementations, the structure shown in Formula I is selected from...

[0090] In some implementations, the structure shown in Formula I is selected from...

[0091] In some implementations, the structure shown in Formula I is selected from...

[0092] In some implementations, the structure shown in Formula I is selected from...

[0093] In some implementations, the structure shown in Formula I is selected from...

[0094] In some implementations, the structure shown in Formula I is selected from...

[0095] In some embodiments, the nucleotide-lipid conjugate monomer comprises the structure shown in formula (I-1).

[0096] in,

[0097] Z 1 Z 2 It does not exist, or each is independently selected from -O-, -S-, -N(R) a)-, -C(=O)-, -OC(=O)-, -C(=O)O-, -C(=O)NR a -、-NR a C(=O)-、-OC(=O)NR a -、-NR a C(=O)O-、-C 1-6 alkylene-, R a Each is independently selected from H and C. 1-6 alkyl;

[0098] Z 3 It is a 5-9 quinone heteroaryl group;

[0099] R 1 C 12-32 Alkyl, the C 12-32 The alkyl group is optionally surrounded by one or more elements selected from H, halogens, OH, CN, NO2, COOH, and -OC. 1-6 Alkyl, -NHC 1-6 Alkyl and -N(C) 1-6 Alkyl group substitution.

[0100] In some implementations, -Z 1 -Z 2 -Does not exist, or selected from -OC 1-6 Alkylene-, -OC 1-6 Alkylene-C(=O)NR a C 1-6 Alkylene-, -NR a C(=O)C 1-6 Alkylene-, -OC(=O)NR a -、-NR a C(=O)O-、-C(=O)NR a -and-NR a C(=O)-,R a Each is independently selected from H and methyl.

[0101] In some implementations, -Z 1 -Z 2 - does not exist, or is selected from -OCH2-C(=O)NHCH2- and -NHC(=O)CH2-.

[0102] In some implementations, Z 3 It is a 5-6 member heteroaryl group.

[0103] In some implementations, Z 3 It is a triazole group.

[0104] In some implementations, Selected from Among them, * end and R 1 Connected.

[0105] In some implementations, R 1 C 14-24 alkyl.

[0106] In some implementations, R 1 Selected from CH2(CH2) 14 CH3 and CH2(CH2) 20 CH3.

[0107] In some embodiments, the nucleotide-lipid conjugate monomer comprises the structure shown in formula (I-1-1).

[0108] in,

[0109] Z 1 Z 2 R 1 As defined in any embodiment of the present invention.

[0110] In some implementations, Selected from

[0111] In some embodiments, the nucleotide-lipid conjugate monomer comprises the structure shown in formula (II).

[0112] in,

[0113] Z 1 Z 2 Z 3 Z 4 R 1 As defined in any embodiment of the present invention;

[0114] X is either O or S;

[0115] Y is O or NR b ;

[0116] R b Selected from H and C 1-6 alkyl;

[0117] B can be a natural or non-natural base, or a modified or unmodified base.

[0118] In some implementations, X is 0.

[0119] In some implementations, Y is O or NR b R b Selected from H and C1-4 alkyl.

[0120] In some implementations, R b Selected from H, methyl, ethyl and isopropyl.

[0121] In some implementations, Y is O.

[0122] In some implementations, B is a nucleotide base or a nucleotide base with a protecting group.

[0123] In some embodiments, B is uracil, cytosine, adenine, guanine, uracil with an amino protecting group, cytosine with an amino protecting group, adenine with an amino protecting group, or guanine with an amino protecting group.

[0124] In some implementations, B is

[0125] In some implementations, B is

[0126] In some embodiments, the nucleotide-lipid conjugate monomer comprises the structure shown in formula (II-1).

[0127] in,

[0128] Z 1 Z 2 Z 3 R 1 X, Y, and B are as defined in any embodiment of the present invention.

[0129] In some embodiments, the nucleotide-lipid conjugate monomer comprises the structure shown in formula (II-1-1).

[0130] in,

[0131] Z 1 Z 2 R 1 X, Y, and B are as defined in any embodiment of the present invention.

[0132] In some implementations, the structure described in formula (II) is selected from the structures shown in Table A:

[0133] Table A

[0134] In some embodiments, the structure described in formula (II) is selected from: LN1, LN2, LN3, LN4, LN5, LN6, LN7, LN8, LN9, LN10, LN11, LN12, LN13, LN14, LN15, LN16, LN17, LN18, LN19, LN20, LN21, LN22, LN23, LN24, LN25 and LN26.

[0135] In some embodiments, the structure described in formula (II) is selected from: LN1, LN2, LN3, LN9, LN14, LN15, LN16, LN17, LN32, LN33, LN34, LN35.

[0136] In some embodiments, the structure described in formula (II) is selected from: LN25, LN26, LN27, LN28, LN29, LN30, LN31.

[0137] In some implementations, the structure described in formula (II) is LN5.

[0138] In some embodiments, the structure described in formula (II) is selected from: LN6, LN7, LN8, LN10, LN11, LN19, LN20, LN21, LN23.

[0139] In some implementations, the structure described in formula (II) is selected from the structures shown in Table B:

[0140] Table B

[0141] In some embodiments, the structure described in formula (II) is selected from: LN1U, LN2U, LN3U, LN4U, LN5U, LN6U, LN7U, LN8U, LN9U, LN10U, LN11U, LN12U, LN13U, LN14U, LN15U, LN16U, LN17U, LN18U, LN19U, LN20U, LN21U, LN22U, LN23U, LN24U, LN25U, LN26U, LN19A, LN1C, LN2C, LN3C, LN9C, LN15C, LN17C.

[0142] In some embodiments, the structure described in formula (II) is selected from: LN1U, LN2U, LN3U, LN9U, LN14U, LN14C, LN15U, LN16U, LN17A, LN17G, LN32U, LN33U, LN34U, LN35U.

[0143] In some embodiments, the structure described in formula (II) is selected from: LN25U, LN26U, LN27U, LN28U, LN29U, LN30U, LN31U.

[0144] In some implementations, the structure described in formula (II) is LN5U.

[0145] In some embodiments, the structure described in formula (II) is selected from: LN6U, LN7U, LN8U, LN10U, LN11U, LN19U, LN20U, LN21U, LN23U.

[0146] In some embodiments, the structure of the nucleotide-lipid conjugate monomer is shown in formula (III).

[0147] in,

[0148] Z 1 Z 2 Z 3 Z 4 R 1 X, Y, and B are as defined in any embodiment of the present invention;

[0149] R 2 R 3 Each is independently selected from H, OH protecting groups and reactive phosphorus groups;

[0150] Or, R 2 and R 3 It connects with adjacent atoms to form a protecting group.

[0151] In some embodiments, the structure of the nucleotide-lipid conjugate monomer is shown in formula (III-1).

[0152] in,

[0153] Z 1 Z 2 Z 3 R 1 X, Y, B, R 2 R 3 As defined in any embodiment of the present invention.

[0154] In some embodiments, the structure of the nucleotide-lipid conjugate monomer is shown in formula (III-1).

[0155] in,

[0156] Z 1 Z 2 R 1X, Y, B, R 2 R 3 As defined in any embodiment of the present invention.

[0157] In some implementations, B is

[0158] In some implementations, B is

[0159] In some implementations, R 2 It is an OH protecting group.

[0160] In some implementations, R 2 Selected from trimethylsilyl (TMS), triethylsilyl (TES), dimethylisopropylsilyl (DMIPS), diethylisopropylsilyl (DEIPS), tert-butyldimethylsilyl (TBDMS), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), acetyl (Ac), chloroacetyl, dichloroacetyl, trichloroacetyl, trifluoroacetyl (TFA), benzoyl, p-methoxybenzoyl, 9-fluorenylmethoxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), 2,2,2-trichloroethoxycarbonyl ( Troc), benzyloxycarbonyl (Cbz), tert-butoxycarbonyl (Boc), benzyl (Bn), p-methoxybenzyl (PMB), allyl, triphenylmethyl (Tr), bis-p-methoxytriphenylmethyl (DMTr), methoxymethyl (MOM), phenoxymethyl (BOM), 2,2,2-trichloroethoxymethyl, 2-methoxyethoxymethyl (MEM), methylthiomethyl (MTM), p-methoxybenzyloxymethyl (PMBM), -C(O)CH2CH2C(O)OH and 4,4'-dimethoxytriphenylmethyl (DMTr).

[0161] In some implementations, R 2 It is 4,4'-dimethoxytriphenylmethyl (DMTr).

[0162] In some implementations, R 2 For H.

[0163] In some implementations, R 3 It is a reactive phosphorus group.

[0164] In some implementations, R 3It is selected from phosphoramide, H-phosphonate, alkyl-phosphonate, phosphate ester and phosphate ester analogue, such as natural phosphate ester, thiophosphate ester, dithiophosphate ester, borane phosphate ester, borane thiophosphate ester, halogen-substituted phosphonate and phosphate ester, aminophosphate ester, phosphate diester, phosphate triester, thiophosphate diester, thiophosphate triester, diphosphate ester or triphosphate ester.

[0165] In some implementations, R 3 for

[0166] In some implementations, R 3 For H.

[0167] In some implementations, R 2 and R 3 It connects with adjacent atoms to form

[0168] In some embodiments, the structure of the nucleotide-lipid conjugate monomer is selected from the structures shown in Table C: Table C

[0169] Oligonucleotides

[0170] A second aspect of the invention provides an oligonucleotide or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein the oligonucleotide comprises one or more nucleotide-lipid conjugate units or pharmaceutically acceptable salts, tautomers, enantiomers, or stereoisomers thereof, the nucleotide-lipid conjugate units comprising the structure shown in formula (I).

[0171] Among them, Z 1 Z 2 Z 3 Z 4 R 1 As defined in any embodiment of the present invention.

[0172] In some embodiments, the nucleotide-lipid conjugate unit comprises the structure shown in formula (II).

[0173] in,

[0174] Z 1 Z 2 Z 3 Z 4 R 1 X, Y, and B are as defined in any embodiment of the present invention.

[0175] In some embodiments, the oligonucleotide is selected from siRNA, miRNA, shRNA, nucleic acid aptamers, ribozymes, and RNA activators.

[0176] In some embodiments, the oligonucleotide is siRNA.

[0177] In some implementations, the siRNA comprises an antisense strand and a sense strand.

[0178] In some implementations, the antisense strand and the sense strand are each independently 15-30 nucleotides in length.

[0179] In some implementations, the antisense strand and the sense strand are each independently 15-25 nucleotides in length.

[0180] In some implementations, the antisense strand and the sense strand are each independently 19-23 (e.g., 19, 20, 21, 22, 23) nucleotides in length.

[0181] In some embodiments, the nucleotide-lipid conjugate unit is located at one or more of the following locations (e.g., locations 1, 2, 3, 4, 5, or 6):

[0182] -The 3' end or 5' end of the antisense chain or the justice chain;

[0183] -The internal location of the antisense chain or the justice chain.

[0184] In some embodiments, the nucleotide-lipid conjugate unit is located at the 3' end of the positive strand.

[0185] In some embodiments, the nucleotide-lipid conjugate unit is located at the 5' end of the positive strand.

[0186] In some embodiments, the nucleotide-lipid conjugate unit is located at positions 2-9 from the 5' end to the 3' end of the positive strand, for example, at positions 2, 3, 4, 5, 6, 7, 8, and 9 from the 5' end to the 3' end of the positive strand. In some embodiments, the nucleotide-lipid conjugate unit is located at positions 2, 3, and 6 from the 5' end to the 3' end of the positive strand.

[0187] In some embodiments, the nucleotide-lipid conjugate unit is located between positions 3 and 9 from the 5' end to the 3' end of the positive strand, for example, at positions 3, 4, 5, 6, 7, 8, and 9 from the 5' end to the 3' end of the positive strand.

[0188] In some embodiments, the nucleotide-lipid conjugate unit is located at positions 2-12 from the 3' end to the 5' end of the positive strand, for example, at positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 from the 3' end to the 5' end of the positive strand. In some embodiments, the nucleotide-lipid conjugate unit is located at positions 3 and 12 from the 3' end to the 5' end of the positive strand.

[0189] In some embodiments, the antisense strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides that are approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides similar to the nucleotide sequence shown in SEQ ID NO:2, and / or

[0190] The positive strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides that are approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides similar to the nucleotide sequence shown in SEQ ID NO:42.

[0191] The positive strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides that are approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides similar to the nucleotide sequence shown in any one of SEQ ID NOs: 1, 3-13.

[0192] In some embodiments, the antisense strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides of approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides that are similar to the nucleotide sequence shown in SEQ ID NO:44, and / or

[0193] The positive strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides that are approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides similar to the nucleotide sequence shown in SEQ ID NO:43.

[0194] In some embodiments, the sense strand and the antisense strand are at least 85% (e.g., at least 90%, at least 95%, at least 99%) complementary on at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides.

[0195] In some embodiments, the sense strand has regions in at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides that are at least 85% complementary to the antisense strand.

[0196] In some embodiments, the siRNA comprises a blunt end and / or a protruding end of 1 to 4 nucleotides.

[0197] In some implementations, the siRNA contains one or two nucleotide overhangs.

[0198] In some embodiments, the protruding end is located at the 5' end and / or 3' end of the antisense chain and / or the justice chain.

[0199] In some embodiments, the 3' end of the antisense strand of the siRNA contains a two-nucleotide overhang.

[0200] intermediate

[0201] A third aspect of the invention provides an intermediate or a pharmaceutically acceptable salt thereof, a tautomer, an enantiomer, or a stereoisomer, wherein the intermediate has a structure represented by formula (M).

[0202] Among them, Z 1 Z 2 R 2 R 3 X, Y, and B are as defined in any embodiment of the present invention;

[0203] R M Selected from -NH2, -CN, -N3, -COOH, -C(=O)OCH3, -C(=O)OCH2CH3,

[0204] In some implementations, R 3 For H.

[0205] In some implementations, R 2 and R 3 It connects with adjacent atoms to form

[0206] In some implementations, Does not exist, or selected from

[0207] In some implementations, Selected from -NH2, -N3,

[0208] In some implementations, the intermediate is selected from:

[0209] Preparation and Use

[0210] The fourth aspect of the invention provides the use of the intermediates described in the third aspect of the invention, or pharmaceutically acceptable salts, tautomers, enantiomers, or stereoisomers thereof, in the preparation of the nucleotide-lipid conjugate monomers described in the first aspect of the invention, or pharmaceutically acceptable salts, tautomers, enantiomers, or stereoisomers thereof, or the oligonucleotides described in the second aspect of the invention, or pharmaceutically acceptable salts, tautomers, enantiomers, or stereoisomers thereof.

[0211] The fifth aspect of the invention provides the use of the nucleotide-lipid conjugate monomer or a pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer of the present invention as described in the first aspect of the invention in the preparation of the oligonucleotide or a pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer of the present invention as described in the second aspect of the invention.

[0212] Pharmaceutical Composition

[0213] A sixth aspect of the invention provides a pharmaceutical composition comprising the oligonucleotide described in the second aspect of the invention or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, and one or more pharmaceutically acceptable carriers and / or excipients.

[0214] Reagent test kit

[0215] A seventh aspect of the present invention provides a kit comprising a nucleotide-lipid conjugate monomer as described in the first aspect of the present invention or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, or an oligonucleotide as described in the second aspect of the present invention or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof.

[0216] Medical Use

[0217] The eighth aspect of the invention provides the use of the oligonucleotides described in the second aspect of the invention or pharmaceutically acceptable salts, tautomers, enantiomers or stereoisomers thereof, or the pharmaceutical compositions described in the sixth aspect of the invention, in the preparation of medicaments for treating and / or preventing diseases.

[0218] The eighth aspect of the invention also provides the oligonucleotides described in the second aspect of the invention or their pharmaceutically acceptable salts, tautomers, enantiomers or stereoisomers, or the pharmaceutical compositions described in the sixth aspect of the invention, for the treatment and / or prevention of diseases.

[0219] The ninth aspect of the present invention provides a method for delivering oligonucleotides to extrahepatic tissues, comprising administering to a subject in need the oligonucleotides described in the second aspect of the present invention or pharmaceutically acceptable salts, tautomers, enantiomers or stereoisomers thereof, or the pharmaceutical compositions described in the sixth aspect of the present invention.

[0220] In some embodiments, the extrahepatic tissue is fat, the central nervous system (CNS), the eye, or muscle.

[0221] The tenth aspect of the present invention provides a method for inhibiting the expression of a target gene in a cell, comprising contacting the cell with an effective amount of the oligonucleotide of the second aspect of the present invention or a pharmaceutically acceptable salt thereof, tautomer, enantiomer or stereoisomer, or a pharmaceutical composition of the sixth aspect of the present invention.

[0222] In some embodiments, the cells are cells from extrahepatic tissues.

[0223] In some embodiments, the extrahepatic tissue is fat, the central nervous system (CNS), the eye, the lungs, or muscle.

[0224] In some embodiments, the target gene is selected from ACVR2A, ACVR2B, ACVR1C, MSTN, PLIN1, TRARG1, CIDEA FABP4, GNG11, CTGF, RAGE, MMP, Mu5ae, SOD1, GFAP, PLP1, APP, MAPT, LRRK2, SNCA, mHTT, ATXN3, ATXN2, TTR, FUS, C9ORF72, PRNP, and MECP.

[0225] In some embodiments, the target gene is selected from ACVR2A, ACVR2B, ACVR1C, MSTN, PLIN1, TRARG1, CIDEA FABP4, GNG11, CTGF, RAGE, MMP, Mu5ae, and SOD1.

[0226] Terminology Definition

[0227] In this application, unless otherwise stated, the scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Furthermore, the cell culture, biochemistry, nucleic acid chemistry, and immunology laboratory procedures used herein are all standard procedures widely used in their respective fields. To better understand this application, definitions and explanations of relevant terms are provided below.

[0228] When the terms “for example,” “such as,” or variations thereof are used in this document, these terms will not be considered restrictive terms but will be interpreted as meaning “including but not limited to” or “not limited to.”

[0229] When this document uses the terms “including,” “contains,” or variations thereof, it also provides the meanings of the terms “consisting of” and “substantially composed of.”

[0230] Unless otherwise specified herein or clearly contradicted by the context, the terms “an” and “a kind” as well as “the” and similar designations shall be interpreted to cover both the singular and the plural in the context of describing the invention (especially in the context of the following claims).

[0231] As used herein, the term “and / or” should be considered as a specific disclosure of each of two or more specified features or elements, and any combination of two or more features or elements. Therefore, the term “and / or” as used in phrases, such as “A and / or B” herein, is intended to include “A and B,” “A or B,” “A” (alone), and “B” (alone).

[0232] As used herein, the terms "target gene" or "target mRNA" refer to any nucleic acid molecule whose expression or activity can be regulated by an siRNA compound; including but not limited to RNA transcribed from DNA encoding a target protein (including but not limited to mRNA precursors and mRNA or portions thereof), cDNA derived from such RNA, and miRNA. For example, a target gene can be a cellular gene (or mRNA transcribed from a gene) whose expression is associated with a specific disorder or disease state. In some embodiments, a target gene can be a nucleic acid molecule derived from an infectious agent.

[0233] As used herein, the term "conjugation" refers to the covalent connection between two or more chemical parts, each possessing a specific function; correspondingly, a "conjugated compound" refers to a compound formed by the covalent connection of these chemical parts. Further, a "nucleotide-lipid conjugation" indicates a compound formed by the covalent attachment of a lipid to a nucleotide. "Lipid" includes, but is not limited to, aliphatic, cyclic alicyclic, polycyclic alicyclic compounds, steroids (e.g., sterols), or straight-chain or branched aliphatic hydrocarbons.

[0234] As used herein, the term "nucleotide" refers to a compound consisting of a base, ribose or deoxyribose, and a phosphate group. The term "base" or "nucleobase" refers to a heterocyclic pyrimidine or purine compound that is a component of a nucleotide, and includes primary purine bases adenine and guanine, and primary pyrimidine bases cytosine, thymine, and uracil, as well as non-natural or modified bases, such as hydrophobic bases or fluorinated bases. Nucleotides can be unmodified or further modified; a "modified nucleotide" is a nucleotide that independently has a modified ribose moiety, a modified nucleoside internucleotide bond, or a modified base. The synthesis of such modified nucleotides (including phosphoramide compounds containing modified nucleotides) is known in the art. In this document, the term "modification" means that modifications applicable to this invention include all types of modifications disclosed herein or known in the art, including but not limited to methoxy modifications, fluorination modifications, thiophosphate linkages, or protecting groups.

[0235] In this article, "methoxy-modified nucleotide" or "2'-O-Me-modified nucleotide" refers to a nucleotide formed by replacing the 2' hydroxyl group of the ribosome with a methoxy group. "Fluoro-modified nucleotide" or "2'-F-modified nucleotide" refers to a nucleotide formed by replacing the 2' hydroxyl group of the ribosome with a fluorine group. "Nucleotide analogue" refers to a group that can replace a nucleotide in nucleic acids but has a structure different from adenine ribonucleotide, guanine ribonucleotide, cytosine ribonucleotide, uracil ribonucleotide, or thymine deoxyribonucleotide. The term "2'-modified RNA phosphoramidite monomer" refers to a nucleotide formed by replacing the 2' hydroxyl group of the ribosome with a phosphoramidite group. The schematic structure of a 2'-O-methyl-modified nucleotide is shown below: The schematic structure of a 2'-fluorine modified nucleotide is shown below. The schematic structure of the thiophosphate bond is as follows:

[0236] In this document, the term "protecting group" refers to any atom or group of atoms added to a molecule to prevent existing groups in the molecule from undergoing undesirable chemical reactions. A "protecting group" can be an unstable chemical motif known in the art, used to protect reactive groups, such as hydroxyl, amino, and thiol groups, from unwanted or untimely reactions during chemical synthesis. Protecting groups are typically used selectively and / or orthogonally to protect sites during reactions at other reactive sites, and can then be removed to leave unprotected groups intact or usable for further reactions. "Protecting groups" include, but are not limited to: acetyl (Ac), benzoyl (Bz), benzyl (Bn), isobutyryl (iBu), phenylacetyl, benzyloxymethyl acetal (BOM), β-methoxyethoxymethyl ether (MEM), methoxymethyl ether (MOM), p-methoxybenzyl ether (PMB), methyl thiomethyl ether, neopentanoyl, tetrahydropyranyl (THP), triphenylmethyl (Trt), methoxytriphenylmethyl [(4-methoxyphenyl)diphenylmethyl] (MMT), dimethoxytriphenylmethyl, [bis-(4-methoxyphenyl)phenylmethyl (DMT), trimethylsilyl ether (TMS), tert-butyldimethylsilyl ether (TBDMS), tri-isopropylsilyloxymethyl ether (TOM), tri-isopropylsilyl ether (TIPS), methyl ether, ethoxyethyl ether (EE), N,N-dimethylformamidinium, and 2-cyanoethyl (CE).

[0237] In this document, the term "hydroxyl protecting group" refers to a group that can prevent the hydroxyl group from undergoing chemical reactions and can be removed under specific conditions to restore the hydroxyl group, such as silane-type protecting groups, acyl-type protecting groups, or ether-type protecting groups, including but not limited to: trimethylsilyl (TMS), triethylsilyl (TES), dimethylisopropylsilyl (DMIPS), diethylisopropylsilyl (DEIPS), tert-butyldimethylsilyl (TBDMS), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), acetyl (Ac), chloroacetyl, dichloroacetyl, trichloroacetyl, trifluoroacetyl, benzoyl, p-methoxybenzoyl, and 9-fluorenyl. Methoxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), 2,2,2-trichloroethoxycarbonyl (Troc), benzyloxycarbonyl (Cbz), tert-butoxycarbonyl (Boc), benzyl (Bn), p-methoxybenzyl (PMB), allyl, triphenylmethyl (Tr), bis-p-methoxytriphenylmethyl (DMTr), methoxymethyl (MOM), phenoxymethyl (BOM), 2,2,2-trichloroethoxymethyl, 2-methoxyethoxymethyl (MEM), methylthiomethyl (MTM), p-methoxybenzylmethyl (PMBM), -C(O)CH2CH2C(O)OH or 4,4'-dimethoxytriphenylmethyl.

[0238] In this article, the term "amino protecting group" refers to a group that prevents the amino group from undergoing chemical reactions and can be removed under specific conditions to restore the amino group. Examples include alkoxycarbonyl amino protecting groups, such as benzyloxycarbonyl (Cbz), tert-butyloxycarbonyl (Boc), fluorenylmethoxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), trimethylsilylethoxycarbonyl (Teoc), and methoxycarbonyl (or ethoxycarbonyl); and acyl amino protecting groups, such as phthaloyl (…). Pht), p-toluenesulfonyl (Tos), trifluoroacetyl (Tfa), o-(p-)nitrobenzenesulfonyl (Ns), tert-pentanoyl, benzoyl (Bz), tert-butoxycarbonyl, 9-fluorenylmethoxycarbonyl, allyloxycarbonyl, trichloroethoxycarbonyl, trimethylsilylethoxycarbonyl, benzyloxycarbonyl, p-methylbenzenesulfonyl, p-nitrobenzenesulfonyl, trifluoroacetyl, methoxycarbonyl, or ethoxycarbonyl; alkyl amino protecting groups, such as triphenylmethyl (Trt), C 1-6 Alkyl-substituted triphenylmethyl, p-methoxytriphenylmethyl (MMT), dimethoxytriphenylmethyl (DMT), 2,4-dimethoxybenzyl (Dmb), 4-methoxybenzyl (PMB), and benzyl (Bn).

[0239] As used herein, the term "reactive phosphorus group" refers to a phosphorus-containing group contained in a nucleotide unit or nucleotide analog unit that can react with a hydroxyl or amino group contained in another molecule, particularly in another nucleotide unit or another nucleotide analog, via a nucleophilic attack reaction. Typically, such a reaction produces an ester-type nucleoside bond linking the first nucleotide unit or the first nucleotide analog unit to the second nucleotide unit or the second nucleotide analog unit. The reactive phosphorus group may be selected from phosphoramides, H-phosphonates, alkyl-phosphonates, phosphate esters, and phosphate ester analogs, including but not limited to: native phosphate esters, thiophosphate esters, dithiophosphate esters, boron phosphate esters, boron thiophosphate esters, phosphonates, halogen-substituted phosphonates and phosphate esters, aminophosphate esters, phosphate diesters, phosphate triesters, thiophosphate diesters, thiophosphate triesters, diphosphate esters, and triphosphate esters, such as -P(OCH2CH2CN)(N(iPr)2).

[0240] As used herein, the term "oligonucleotide" refers to a nucleic acid molecule having a length of less than, for example, 50, 100, 200, 300, or 400 nucleotides. In this text, the term "oligomery" refers to a polymer composed of certain repeating units.

[0241] As used herein, the term "RNAi agent" refers to a composition comprising an RNA or RNA-like (e.g., chemically modified RNA) oligonucleotide molecule capable of degrading or inhibiting (e.g., under appropriate conditions, degrading or inhibiting) the translation of a messenger RNA (mRNA) transcript of a target mRNA in a sequence-specific manner. As used herein, RNAi agents may act via RNA interference mechanisms (i.e., by interacting with RNA interference pathways in mammalian cells, such as RNA-induced silencing complexes or RISC) or via any alternative mechanism or pathway. While the term RNAi agent as used herein primarily acts via RNA interference mechanisms, the RNAi agents disclosed herein are not limited to any particular pathway or mechanism of action. The RNAi agents disclosed herein consist of a sense strand and an antisense strand, and include, but are not limited to, small interfering RNA (siRNA), double-stranded RNA (dsRNA), microRNA (miRNA), short hairpin RNA (shRNA), and dicer substrates. The antisense strand of the RNAi agents described herein is at least partially complementary to the targeted mRNA (i.e., PNPLA3 mRNA). RNAi agents may contain one or more modified nucleotides and / or one or more non-phosphodiester bonds.

[0242] As used herein, the term "siRNA" refers to an RNA molecule capable of sequence-specifically inducing RNAi, consisting of a sense strand and an antisense strand, and having a partially or fully complementary double-stranded structure. In the siRNAs involved in this invention, the length of the complementary double-stranded structure can be 15-30 base pairs, for example, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, or 25 base pairs. In some embodiments of this invention, the siRNA may also contain modified nucleotides as needed, which do not significantly weaken or lose the function of the siRNA in inhibiting target gene expression. Currently, there are various ways in the art to modify siRNA, including, for example, backbone modification (such as phosphate group modification), ribose group modification, and base modification (Watts, JK, G.F. Deleavey, and M.J. Damha, Chemically Modified siRNA: Tools and Applications. Drug Discov Today, 2008, 13(19-20): p. 842-55). In this document, unless otherwise stated, nucleotides or modified nucleotides in siRNA are linked by 3',5'-phosphodiester bonds. For example, in the SD02 positive strand, the 5' end of position 5 (U) and the 6th position (LN1U) are linked by a 3',5'-phosphodiester bond, and the 6th position (LN1U) and the 7th position (A) are linked by a 3',5'-phosphodiester bond. In this document, unless otherwise stated, the 5' end of siRNA is a free phosphate group, and the 3' end is a free hydroxyl group. For example, the 3' end of the SD25 positive strand is a free hydroxyl group. It is known to those skilled in the art that phosphate has a low pKa, approximately 2; therefore, in strongly acidic environments (e.g., pH < 2), the phosphate group is an undissociated phosphate group. In normal neutral environments (such as pH 7, or under physiological conditions) or even alkaline environments, the phosphate group loses two protons, exhibiting [a state of flux / property]. The structure of any form, regardless of its representation, is within the scope of this application.

[0243] As used herein, the term "antisense strand" includes a region substantially complementary to the target sequence. The term "sense strand," as used herein, refers to the strand of a region substantially complementary to the antisense strand. The term "complementary region" refers to a region on the antisense strand substantially complementary to the target mRNA or a region on the sense strand substantially complementary to the antisense strand. When a complementary region is not perfectly complementary to the target sequence or the antisense strand, a mismatch can occur within the molecule or in terminal regions. Typically, the most permissible mismatches are in terminal regions, for example, within 5, 4, 3, 2, or 1 nucleotides at the 5' and / or 3' ends.

[0244] In this document, unless otherwise specified, the term "complementary" refers to the ability of an oligonucleotide of a first sequence to hybridize with an oligonucleotide of a second sequence under certain conditions and form a double-stranded structure. "At least partially complementary" means that the two sequences can be completely complementary, or have no more than 6, 5, 4, 3, 2, or 1 mismatched base pairs in total, while retaining the ability to hybridize under the relevant conditions. Furthermore, where the two oligonucleotides are designed to form one or more single-stranded overhangs upon hybridization, such overhangs should not be considered mismatches for determining complementarity. In this document, to satisfy the above hybridization ability requirements, a "complementary" sequence may also include base pairs formed entirely from non-Watson-Crick base pairs and / or from non-natural and modified nucleotides. Such non-Watson-Crick base pairs include, but are not limited to, G:U swing base pairs or Hoogstein base pairs. Correspondingly, in this article, unless otherwise specified, "mismatch" refers to a situation in the siRNA double-stranded molecule where the bases at corresponding positions are not paired in a complementary manner.

[0245] In this document, the term "protrusion" or "nucleotide protrusion" refers to at least one unpaired nucleotide protruding from the double-stranded structure of siRNA. For example, a protrusion exists when the 3' end of one strand of siRNA extends beyond the 5' end of the other strand (or vice versa). siRNA may contain at least one nucleotide protrusion, or a protrusion may contain at least two, three, four, five, or more nucleotides. A protrusion may contain, or be composed of, nucleotide / nucleoside analogs, including deoxynucleotides / nucleosides. A protrusion may be on the sense strand, antisense strand, or any combination thereof. The nucleotide of the protrusion may be present at the 5' end, 3' end, or both ends of the antisense strand or sense strand of siRNA. Accordingly, the term "flat end" refers to the absence of a nucleotide protrusion.

[0246] As used herein, when referring to the expression of a given gene, the terms “silence,” “reduction,” “inhibition,” “downregulation,” or “knockdown” mean that when a cell, cell population, tissue, organ, or subject is treated with the RNAi agent described herein, the expression of the gene is reduced compared to a second cell, cell population, tissue, organ, or subject that has not been treated in this way, as measured by the level of RNA transcribed from the gene or the level of polypeptides, proteins, or protein subunits translated from mRNA in the cell, cell population, tissue, organ, or subject in which the gene was transcribed.

[0247] As used herein, the term "stereoisomer" refers to an isomer formed by at least one asymmetric center. In compounds having one or more (e.g., 1, 2, 3, or 4) asymmetric centers, racemic mixtures, single enantiomers, diastereomer mixtures, and individual diastereomers can be produced. Specific individual molecules may also exist as geometric isomers (cis / trans).

[0248] Similarly, the compounds described herein can exist as mixtures of two or more structurally distinct forms in rapid equilibrium (commonly referred to as tautomers). Representative examples of tautomers include keto-enol tautomers, phenol-keto tautomers, nitroso-oxime tautomers, imine-enamine tautomers, and so on. It should be understood that the scope of this document covers all such isomers or mixtures thereof in any proportion (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99%).

[0249] As used herein, the term “enantiomer” refers to one of a pair of molecular entities that are mirror images of each other and cannot be overlapped. A mixture of enantiomers can be separated, for example, under chiral resolution conditions.

[0250] Unless otherwise stated, the compounds described herein may exist as stereoisomers (including cis and trans isomers, optical isomers (e.g., R and S enantiomers), diastereomers, geometric isomers, rotational isomers, conformational isomers, trans-blocking isomers, and mixtures thereof). The compounds described herein may exhibit more than one type of isomerism and may consist of mixtures thereof (e.g., racemic mixtures and diastereomer pairs).

[0251] As used herein, the term "pharmaceutically acceptable salt" refers to a salt that retains the bioavailability and properties of a compound or conjugate, and is biologically or otherwise suitable for use in pharmaceuticals. In many cases, the prodrugs disclosed herein can form acid and / or base salts in the presence of amino and / or carboxyl or similar groups. Pharmaceutically acceptable acid addition salts can consist of inorganic and organic acids. Inorganic acids that can be derivatized to form salts include, for example, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, etc. Organic acids that can be derivatized to form salts include, for example, acetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid, maleic acid, malonic acid, succinic acid, fumaric acid, tartaric acid, citric acid, benzoic acid, cinnamic acid, mandelic acid, methanesulfonic acid, ethanesulfonic acid, p-toluenesulfonic acid, salicylic acid, etc. Pharmaceutically acceptable base addition salts can consist of inorganic and organic bases. Inorganic bases that can be derived to form salts include, for example, sodium, potassium, lithium, ammonium, calcium, magnesium, iron, zinc, copper, manganese, and aluminum; particularly preferred are ammonium, potassium, sodium, calcium, and magnesium salts. Organic bases that can be derived to form salts include, for example, primary, secondary, and tertiary amines, substituted amines including naturally occurring substituted amines, cyclic amines, basic ion exchange resins, etc., specifically, isopropylamine, trimethylamine, diethylamine, triethylamine, tripropylamine, and ethanolamine. Many such salts are known in the art, such as those described in WO87 / 05297 by Johnston et al., published on September 11, 1987 (which is incorporated herein by reference in its entirety).

[0252] As used in this application, when a variable does not exist, the two adjacent groups connected by that variable are directly connected, for example, in equation (I), when Z 4 If it does not exist, then Z 3 With R 1 Directly connected.

[0253] As used herein, the term "optionally substituted" means that the group may be unsubstituted or substituted, for example, "C..." 1-6 "Alkyl optional halogen substitution" indicates C 1-6 Alkyl groups can be unsubstituted or substituted with halogens to give haloalkyl groups. It should be understood that -N-(C 1-6 Alkyl)2 indicates that two carbon atoms are attached to the nitrogen atom. 1-6 Alkyl groups, which can be the same or different.

[0254] As used herein, unless otherwise explicitly stated, the descriptive phrase “…each independently selected” throughout this document can mean either that the specific options expressed by the same or different symbols in different groups do not affect each other, or that the specific options expressed by the same or different symbols in the same group do not affect each other.

[0255] As used in this article, the term "halogen" refers to fluorine, chlorine, bromine, and iodine.

[0256] As used herein, the term "alkyl" refers to a straight-chain or branched monovalent saturated hydrocarbon group, such as C 1-6 Alkyl groups refer to those having 1 to 6 carbon atoms, such as 1, 2, 3, 4, 5, or 6 carbon atoms. The C... 1-6 Alkyl groups include C 1-5 Alkyl, C 1-4 Alkyl groups, etc. Non-limiting examples of alkyl groups include methyl, ethyl, propyl, butyl, etc., wherein the propyl group includes n-propyl and isopropyl, and the butyl group includes n-butyl, isobutyl, and neobutyl.

[0257] As used herein, the term "alkenyl" refers to a straight-chain or branched unsaturated hydrocarbon group containing at least one double bond. 2- 6-alkenyl refers to a group having 2 to 6 (e.g., 2, 3, 4, 5, or 6) carbon atoms, including C. 2-5 alkenyl, C 2-4 alkenyl, C 2-3 Alkenes, etc., non-limiting examples include -CH=CH2, -CH=CH-CH=CH2 or -CH=C(CH)3-CH3, etc.

[0258] As used herein, the term "alkynyl" refers to a straight-chain or branched unsaturated hydrocarbon group containing at least one triple bond, for example, C. 2-6 The alkynyl group refers to a group having 2 to 6 (e.g., 2, 3, 4, 5, or 6) carbon atoms, including C. 2-5 alkynyl group, C 2-4 alkynyl group, C 2-3 Alkyne groups, etc. Non-limiting examples of alkynyl groups include ethynyl or propynyl, etc.

[0259] As used herein, the term "cycloalkyl" refers to a saturated cyclic hydrocarbon group consisting of carbon atoms. For example, C 3-9 The cycloalkyl group has 3 to 9 carbon atoms, such as 3, 4, 5, 6, 7, 8, or 9 carbon atoms, wherein the C 3-9 Cycloalkyl groups include C 3- 8-cycloalkyl, C 3-6 cycloalkyl, C 6-8 Cycloalkyl groups, etc. The cycloalkyl groups include monocyclic, bicyclic, or polycyclic rings, including spirocyclic, fused, or bridged rings. Non-limiting examples of cycloalkyl groups include cyclohexyl, cycloheptyl, adamantyl, etc.

[0260] As used herein, the term "heterocyclic group" refers to a saturated or partially unsaturated monovalent cyclic group composed of ring atoms, wherein one, two, three, or four ring atoms are heteroatoms, and the remainder are carbon atoms; preferably, the heteroatoms are selected from N, O, or S, wherein the nitrogen atom is optionally quaternized, and the nitrogen and sulfur heteroatoms may optionally be oxidized. For example, a 4-9 heterocyclic group refers to a group composed of 4-9 ring atoms, including 5-7 membered heterocyclic groups, 4-8 membered heterocyclic groups, 4-6 membered heterocyclic groups, etc. The heterocyclic group includes monocyclic, bicyclic, or polycyclic rings, including spirocyclic, fused, or bridged rings. Non-limiting examples of heterocyclic groups include oxoheterobutyl, azirrobutyl, pyrrolidinyl, piperidinyl, piperazinyl, or morpholinyl, etc.

[0261] As used herein, the term "heteroaryl" refers to an unsaturated group consisting of ring atoms with a conjugated π-electron system, wherein 1, 2, 3, or 4 ring atoms are heteroatoms and the remainder are carbon atoms; preferably, the heteroatoms are selected from N, O, or S, wherein the nitrogen atom is optionally quaternized, and the nitrogen and sulfur heteroatoms may optionally be oxidized. For example, 5-9-membered heteroaryls consist of 5 to 9 (e.g., 5, 6, 7, 8, or 9) ring atoms, including 5-6-membered heteroaryls, etc. The heteroaryls include monocyclic and polycyclic compounds, and non-limiting examples include imidazolyl, pyridinyl, quinolinyl, or isoquinolinyl, etc.

[0262] As used herein, the term “alkylene” refers to a divalent group, for example, “alkylene” refers to a divalent group formed by the loss of a hydrogen atom from an alkyl group, and the “alkyl” is as defined above.

[0263] As used herein, the term "pharmaceutically acceptable carrier and / or excipient" means a carrier and / or excipient that is pharmacologically and / or physiologically compatible with the subject and the active ingredient, which is well known in the art (see, for example, Remington's Pharmaceutical Sciences. Edited by Gennaro AR, 19th ed. Pennsylvania: Mack Publishing Company, 1995), and includes, but is not limited to: pH adjusters, surfactants, adjuvants, ionic strength enhancers, diluents, osmotic pressure maintaining agents, absorption delaying agents, and preservatives. For example, pH adjusters include, but are not limited to, phosphate buffers. Surfactants include, but are not limited to, cationic, anionic, or nonionic surfactants, such as Tween-80. Ionic strength enhancers include, but are not limited to, sodium chloride. Preservatives include, but are not limited to, various antibacterial and antifungal agents, such as parabens, chlorobutanol, phenol, sorbic acid, etc. Osmotic pressure maintaining agents include, but are not limited to, sugars, NaCl, and their analogues. Absorption delaying agents include, but are not limited to, monostearates and gelatin. Diluents include, but are not limited to, water, aqueous buffers (such as buffered saline), alcohols, and polyols (such as glycerol). Stabilizers have the meaning commonly understood by those skilled in the art for stabilizing the desired activity of the active ingredient in a pharmaceutical product, including but not limited to monosodium glutamate, gelatin, SPGA, sugars (such as sorbitol, mannitol, starch, sucrose, lactose, dextran, or glucose), amino acids (such as glutamic acid, glycine), proteins (such as dried whey, albumin, or casein) or their degradation products (such as lactalbumin hydrolysate).

[0264] As used herein, the term "prevention" refers to a method implemented to prevent or delay the occurrence of a disease, condition, or symptom (e.g., a tumor) in a subject. As used herein, the term "treatment" refers to a method implemented to obtain a beneficial or desired clinical outcome. For the purposes of this application, a beneficial or desired clinical outcome includes, but is not limited to, alleviating symptoms, reducing the extent of the disease, stabilizing (i.e., no longer worsening) the state of the disease, delaying or slowing the progression of the disease, improving or alleviating the state of the disease, and relieving symptoms (whether partial or complete), whether detectable or undetectable. Furthermore, "treatment" can also refer to prolonged survival compared to expected survival (if no treatment was received).

[0265] As used herein, the term "subject" refers to a mammal, such as a primate mammal, like a human. In some embodiments, the subject (e.g., a human) suffers from hepatitis B, particularly chronic hepatitis B.

[0266] As used herein, the term "effective amount" means an amount sufficient to achieve, or at least partially achieve, the desired effect. For example, an effective amount for treating a disease means an amount sufficient to cure or at least partially prevent the disease and its complications in a patient already suffering from the disease. Determining such an effective amount is entirely within the capabilities of those skilled in the art. For example, an effective amount for therapeutic use will depend on the severity of the disease to be treated, the overall state of the patient's own immune system, the patient's general characteristics such as age, weight, and sex, the manner of administration of the drug, and other concurrent treatments, etc. Beneficial effects

[0267] The nucleotide-lipid conjugates provided by this invention help improve the extrahepatic delivery efficiency of siRNA and inhibit the expression of target genes. Attached Figure Description

[0268] Figure 1.3 Relative amount of SOD1 mRNA in T3-L1 cells (transfection uptake);

[0269] Figure 2.3 Relative amount of SOD1 mRNA remaining in T3-L1 cells (transfection uptake);

[0270] Figure 3.3 Relative amount of SOD1 mRNA in T3-L1 cells (free uptake);

[0271] Figure 4.3 Relative amount of SOD1 mRNA in T3-L1 cells (free uptake);

[0272] Figure 5. Relative amount of SOD1 mRNA in L929 cells (free uptake);

[0273] Figure 6. Relative amount of SOD1 mRNA in L929 cells (free uptake);

[0274] The Blank group contained only test cells, the Mock group contained only transfection reagents, and the No C22 group used No C22 (sense strand as shown in SEQ ID No:15, antisense strand as shown in SEQ ID No:2) as siRNA. Detailed Implementation

[0275] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0276] The abbreviations used in this invention have the following meanings.

[0277] Example 1

[0278] Step 1: Synthesis of tetracoyne-1-yne (compounds 1-2)

[0279] Under nitrogen protection at 21°C, lithium ethylenediamine complex (1.54 g, 16.69 mmol, 3.25 eq) was dissolved in DMSO (8 mL). 1-Bromodocoane (compound 1-1, 2.00 g, 5.13 mmol, 1.0 eq) was added to the reaction solution. The reaction was carried out at 21°C under nitrogen protection for 2.5 h, then increased to 66°C and reacted for another 0.5 h. The reaction was stopped by TLC monitoring. The reaction solution was adjusted to pH 1 with 1M HCl. Saturated sodium chloride aqueous solution (20 mL) was added to the reaction solution, and the mixture was extracted with EA (20 mL * 3). The combined organic phases were washed with 1M HCl (20 mL * 2), followed by washing with saturated sodium chloride aqueous solution (20 mL * 2). The mixture was dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure to obtain tetratetryn-1-yne (compound 1-2, 1.46 g, crude product), which was used directly in the next step.

[0280] 1 H NMR (400MHz, CDCl3) δ2.52(td,J=7.1,2.7Hz,2H),2.27(t,J=2.7Hz,1H),1.91–1.82(m,2H),1.76–1.70(m,2H),1.61(s,36H),1.22(t,J=6.8Hz,3H).

[0281] Step 2: Synthesis of (2R,3R,3aS,9aR)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-hydroxy-2,3,3a,9a-tetrahydro-6H-furano[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one (compounds 1-4)

[0282] At 0 °C, 2,2'-dehydro-uridine (compounds 1-3, 5.00 g, 22.1 mmol, 1.0 eq) was dissolved in anhydrous pyridine (50 mL). 4,4'-bismethoxytriphenylmethylchloromethane (DMTrCl, 4.12 g, 12.2 mmol, 0.55 eq) was added in portions, and the temperature was restored to 21 °C, and the reaction continued for 1 hour. After 1 hour, the reaction temperature was lowered to 0 °C, and DMTrCl (4.12 g, 12.2 mmol, 0.55 eq) was added in portions to the reaction solution. The temperature was then restored to 21 °C, and the reaction continued for 1 hour. The reaction was monitored by TLC until completion. Water (50 mL) was added to the reaction solution, and the mixture was extracted with DCM (20 mL * 3). The combined organic phases were washed successively with saturated sodium chloride aqueous solution (20 mL * 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. Purified by normal column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 7% B to 15% B), the eluent was collected, concentrated under reduced pressure, and dried under vacuum to give (2R,3R,3aS,9aR)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-hydroxy-2,3,3a,9a-tetrahydro-6H-furano[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one (compounds 1-4, 9.1 g, yield: 78%).

[0283] 1 H NMR(400MHz,DMSO-d6)δ7.95(d,J=7.4Hz,1H),7.35–7.19(m,5H),7.17–7.12(m,4H) ,6.87–6.81(m,4H),6.33(d,J=5.6Hz,1H),5.96(d,J=4.5Hz,1H),5.88(d,J=7.4Hz,1 H),5.21(dd,J=5.7,1.2Hz,1H),4.36–4.27(m,1H),4.22(ddd,J=7.3,4.4,2.8Hz,1H ), 3.73 (d, J = 1.6Hz, 6H), 2.95 (dd, J = 10.3, 4.4Hz, 1H), 2.82 (dd, J = 10.3, 7.3Hz, 1H).

[0284] Step 3: Synthesis of 1-((2R,3R,4S,5R)-3-azido-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compounds 1-5)

[0285] Lithium fluoride (353.3 mg, 13.62 mmol, 1.8 eq) was dissolved in N,N-dimethylformamide (27 mL) under nitrogen protection at 21 °C. After heating to 110 °C in an oil bath, N,N,N',N'-tetramethylethylenediamine (27 mL) and azide-trimethylsilane (1.57 g, 13.62 mmol, 1.8 eq) were added sequentially. After reacting for 1 hour under nitrogen protection at 110 °C, the starting materials 2R,3R were added. A solution of N,N-dimethylformamide (7 mL) of bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-hydroxy-2,3,3a,9a-tetrahydro-6H-furano[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one (compound 1-4, 4.0 g, 7.57 mmol, 1.0 eq) was added to the reaction solution, and the reaction was carried out at 105 °C under nitrogen protection for 16 hours. TLC monitoring showed that the reactants had largely reacted. After the reaction was brought back to room temperature, water (20 mL) was added to the reaction solution, and the mixture was extracted with EA (30 mL * 3). The organic phase was collected, washed with saturated sodium chloride aqueous solution (20 mL * 2), dried over anhydrous sodium sulfate, filtered, and the solvent was evaporated under reduced pressure to obtain the crude product. Purified by normal column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 55% B to 60% B), the eluent was collected, concentrated under reduced pressure, and dried under vacuum to give 1-((2R,3R,4S,5R)-3-azido-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 1-5, 1.42 g, yield: 33%).

[0286] 1 H NMR (400MHz, DMSO-d6) δ11.44(s,1H),7.69(d,J=8.1Hz,1H),7.40–7.29(m,4H ),7.24(dq,J=7.5,2.7Hz,5H),6.90(dd,J=8.8,1.3Hz,4H),5.99(d,J=5.9Hz,1 H),5.79–5.71(m,1H),5.36(d,J=8.1Hz,1H),4.42(q,J=6.1Hz,1H),4.26(dd,J =5.8,3.8Hz,1H),3.96(dt,J=7.4,3.8Hz,1H),3.74(s,6H),3.32–3.22(m,2H).

[0287] Step 4: Synthesis of 1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(4-dococosyl-1H-1,2,3-triazol-1-yl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compounds 1-6)

[0288] Under nitrogen protection at 21°C, 1-((2R,3R,4S,5R)-3-azido-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 1-5, 770 mg, 1.35 mmol) and icostyne-1-yne (compound 1-2, 901.6 mg, 2.69 mmol, 2.0 eq) were dissolved in a mixed solvent (10 mL) of tetrahydrofuran / tert-butanol / water (3 / 1 / 1). CuSO4 (64.5 mg, 0.41 mmol, 0.3 eq) and sodium vitamin C (400.3 mg, 2.02 mmol, 1.5 eq) were added to the reaction solution, and the reaction was carried out for 16 hours under nitrogen protection at 21°C. The reaction was monitored by TLC until complete. Water (15 mL) was added to the reaction solution, and the mixture was extracted with EA (20 mL * 3). The combined organic phases were washed sequentially with saturated sodium chloride aqueous solution (20 mL * 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified by normal column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 45% B to 55% B). The eluent was collected, concentrated under reduced pressure, and dried under vacuum to give 1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(4-dococoyl-1H-1,2,3-triazol-1-yl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compounds 1-6, 1.06 g, yield: 87%).

[0289] 1H NMR (400MHz, DMSO-d6) δ11.41(d,J=2.1Hz,1H),7.85–7.80(m,2H),7.45–7.38(m,2H),7.32(t,J=7 .6Hz,2H),7.30–7.22(m,5H),6.93–6.88(m,4H),6.40(d,J=4.8Hz,1H),5.75(d,J=5.7Hz,1H),5.4 7–5.40(m,2H),4.50(q,J=6.3Hz,1H),4.22(td,J=5.5,3.0Hz,1H),3.74(s,6H),3.40–3.33(m,1H) ,3.32–3.26(m,1H),2.61(t,J=7.6Hz,2H),1.58(p,J=7.2Hz,2H),1.23(s,38H),0.87–0.80(m,3H).

[0290] Step 5: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(4-dococosyl-1H-1,2,3-triazol-1-yl)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N1U)

[0291] Pretreatment: 1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(4-dococoyl-1H-1,2,3-triazol-1-yl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compounds 1-6, 300 mg, 1 eq, 0.331 mmol) was dissolved in anhydrous pyridine (5 mL), concentrated under reduced pressure to remove trace amounts of water, repeated 3 times, and dried under an oil pump for 30 min. Anhydrous magnesium sulfate (1.2 g, 4 w / w) was added to a three-necked flask, and then heated with a torch until no bubbles were generated. After cooling to room temperature, the mixture was purged with nitrogen.

[0292] At room temperature, pretreated 1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(4-dococosyl-1H-1,2,3-triazol-1-yl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compounds 1-6) were dissolved in anhydrous dichloromethane (12 mL), and then added to a three-necked flask containing pretreated magnesium sulfate. N,N-diisopropylamine (3 mL) was added with stirring. A solution of 42 mg (2.65 mmol, 8 eq) and N-methylimidazole (13.6 mg, 0.166 mmol, 0.5 eq) in anhydrous dichloromethane (2 mL) was cooled to 0 °C and stirred for 5 min. Then, a solution of N,N-diisopropylphosphonamide (2-cyanoethyl) ester (624 mg, 2.65 mmol, 8 eq) in anhydrous dichloromethane (3 mL) was slowly added dropwise. After the addition was complete, the temperature was raised to 25 °C and stirred for 1 h. The reaction mixture was monitored by TLC to ensure complete reaction. The reaction solution was filtered, and the filter cake was washed with DCM (20 mL). The filtrate was extracted with saturated sodium bicarbonate aqueous solution (30 mL), and the aqueous phase was extracted with dichloromethane (20 mL). The organic phases were combined and washed successively with saturated sodium chloride solution (20 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. Purified by normal column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 40% B). The eluent was collected and concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(4-dococosyl-1H-1,2,3-triazol-1-yl)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N1U, 320 mg, yield: 87%).

[0293] 1H NMR (400MHz, DMSO-d6) δ11.44(s,1H),7.85(d,J=7.6Hz,2H),7.42(d,J=7.3Hz,2H),7.36–7.21(m,7H),6.90( dd,J=9.0,2.5Hz,4H),6.38(d,J=4.8Hz,1H),5.70–5.64(m,1H),5.48(dd,J=8.2,1.9Hz,1H),4.65(dt,J=12. 1,6.5Hz,1H),4.44(s,1H),3.74(s,6H),3.53(q,J=6.8Hz,2H),3.46–3.34(m,2H),3.27(s,2H),2.57(t,J=7. 6Hz,2H),2.48–2.45(m,2H),1.61–1.50(m,2H),1.25–1.19(m,38H),1.00(d,J=6.8Hz,6H),0.88–0.80(m,9H).

[0294] 31 P NMR(162MHz,DMSO-d6)δ150.03,148.26.

[0295] Example 2

[0296] Step 1: Synthesis of 1-azidocosane (compound 2-1)

[0297] At room temperature, 1-bromodocosahexadecane (compound 1-1, 10 g, 25.7 mmol, 1.0 eq) was dissolved in N,N-dimethylformamide (100 mL), and sodium azide (8.34 g, 128.4 mmol, 5.0 eq) was added. The reaction mixture was heated to 70 °C and stirred for 2 hours. TLC showed that the reaction was complete. The reaction mixture was slowly added dropwise to ice water (300 mL), and a white solid precipitated. The solid was filtered, and the filter cake was dried under vacuum for 16 hours to give 1-azidodocosahexadecane (compound 2-1, 8.6 g, yield: 95%).

[0298] Step 2: Synthesis of 1-((6aR,8R,9R,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilacyclooctane-8-yl)pyrimidine-2,4(1H,3H)-dione (compounds 2-3)

[0299] Under nitrogen protection and in an ice bath, 1,3-dichloro-1,1,3,3-tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 2-2,2 g, 8.2 mmol, 1 eq) was slowly added dropwise to an ultra-dry pyridine (15 mL) solution. After the addition was complete, the temperature was slowly raised to 25 °C and stirred for 17 hours. The reaction solution was concentrated under reduced pressure. The residue was diluted with ethyl acetate (20 mL) and poured into 2N dilute hydrochloric acid (50 mL). Ethyl acetate was used for extraction (20 mL x 3). The organic phase was washed with 2N dilute hydrochloric acid (20 mL) and saturated sodium chloride solution (20 mL), respectively. The mixture was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The residue was purified by normal column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 50% B). The eluent was collected and concentrated under reduced pressure to give 1-((6aR,8R,9R,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilicyclooctane-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 2-3, 3.4 g, yield: 85.4%).

[0300] MS:m / z 487.22[M+H] + .

[0301] 1 H NMR (400MHz, DMSO-d6) δ11.37(s,1H),7.70(d,J=8.2Hz,1H),5.59(d,J=4.6Hz,1H) ,5.55(d,J=9.6Hz,2H),4.19–4.12(m,3H),4.03–3.91(m,2H),1.10–1.01(m,28H).

[0302] Step 3: Synthesis of 3-benzoyl-1-((6aR,8R,9S,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilylonoctane-8-yl)pyrimidine-2,4(1H,3H)-dione (compounds 2-4)

[0303] Under ice bath conditions, Na₂CO₃ (9.65 g, 91 mmol, 7.0 eq) and tetrabutylammonium bromide (168 mg, 0.52 mmol, 0.04 eq) were added to a mixed solution of 1-((6aR,8R,9R,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilylonoctane-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 2-3, 6.3 g, 13 mmol, 1.0 eq) in dichloromethane (120 mL) and water (240 mL). Then, benzoyl chloride (2.36 g, 16.8 mmol, 1.3 eq) was slowly added dropwise to the reaction solution. After the addition was complete, the system was heated to 25 °C and stirred for 16 hours. TLC showed the reaction was complete. The reaction solution was allowed to stand and separate into layers. The aqueous phase was extracted with dichloromethane (150 mL). The organic phases were combined, washed with saturated sodium chloride aqueous solution (100 mL), dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was purified by normal column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 25% B). The eluent was collected and concentrated under reduced pressure to give 3-benzoyl-1-((6aR,8R,9S,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilicyclooctane-8-yl)pyrimidin-2,4(1H,3H)-dione (compound 2-4, 5.0 g, yield: 65%).

[0304] MS: m / z 613.26 [M+Na] + .

[0305] 1 H NMR(400MHz, DMSO-d6)δ8.04–7.96(m,2H),7.86(d,J=8.3Hz,1H),7.83–7.75(m,1H),7.61(t,J=7.8Hz,2H),5.82 (d,J=8.2Hz,1H),5.66(d,J=4.5Hz,1H),5.58(s,1H),4.24–4.13(m,3H),4.08–3.90(m,2H),1.14–0.93(m,28H).

[0306] Step 4: Synthesis of ethyl 2-(((6aR,8R,9S,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilicyclooctane-9-yl)oxy)acetate (compounds 2-5)

[0307] Under ice bath conditions, 3-benzoyl-1-((6aR,8R,9S,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilicyclooctane-8-yl)pyrimidin-2,4(1H,3H)-dione (compound 2-4, 2.0 g, 3.39 mmol, 1.0 eq) was dissolved in a mixed solvent of ethyl bromoacetate (10 mL) and toluene (10 mL). After purging with nitrogen, tetrabutylammonium iodide (626 mg, 1.69 mmol, 0.5 eq) was added, followed by the slow addition of NaOH aqueous solution (10 mL, 60% w / v). The reaction was carried out at 0 °C for 5 minutes. TLC showed that the reaction was essentially complete. The reaction solution was then poured into water. Extracted with dichloromethane (120 mL), washed with saturated sodium chloride aqueous solution (60 mL), dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 30% B). The eluent was collected and concentrated under reduced pressure to obtain ethyl 2-(((6aR,8R,9S,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilicyclooctane-9-yl)oxy)acetate (compound 2-5, 1.95 g, yield: 85%).

[0308] MS:m / z 677.30[M+H] + .

[0309] 1 HNMR (400MHz, DMSO-d6) δ8.03–7.95(m,2H),7.88–7.75(m,2H),7.65–7.56(m,2H),5.84(d,J=8.2Hz,1H),5.72(s,1H),4.40(d,J=16.5Hz ,1H),4.36–4.27(m,3H),4.22–4.13(m,1H),4.08–4.02(m,3H),3.94(dd,J=13.5,2.5Hz,1H),1.13(t,J=7.0Hz,3H),1.10–0.93(m,28H).

[0310] Step 5: Synthesis of methyl 2-(((6aR,8R,9S,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)methyl acetate (compounds 2-6).

[0311] Under ice bath conditions, K2CO3 (815 mg, 5.9 mmol, 2.0 eq) was added to a MeOH (25 mL) solution of ethyl 2-(((6aR,8R,9S,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilicyclooctane-9-yl)oxy)acetate (compound 2-5, 2 g, 2.95 mmol, 1.0 eq), and the mixture was stirred at room temperature for 2 h. TLC showed that the reactants reacted completely. The reaction solution was diluted with dichloromethane (50 mL) and poured into water (50 mL). It was extracted with dichloromethane (30 mL). The organic phase was washed with dilute hydrochloric acid solution (0.1 N, 30 mL) and saturated sodium chloride solution (30 mL), respectively. It was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain methyl 2-(((6aR,8R,9S,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisili-9-yl)oxy)methyl acetate (compound 2-6, 1.5 g, crude product), which was directly used in the next step.

[0312] MS:m / z 559.21[M+H] + .

[0313] Step 6: Synthesis of methyl 2-(((2R,3S,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)acetic acid methyl ester (compounds 2-7)

[0314] Under ice bath conditions, tetrabutylammonium fluoride (6.7 mL, 6.7 mmol, 2.5 eq, 1 M in THF) was added dropwise to a tetrahydrofuran (15 mL) solution of methyl 2-(((6aR,8R,9S,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)acetate (compound 2-6, 1.5 g, 2.7 mmol, 1.0 eq) of [amount missing]. After the addition was complete, the temperature was slowly raised to 25 °C, and stirring was continued for 1 h. TLC showed that the reaction was complete. The reaction solution was concentrated and dissolved in ethyl acetate (30 mL), washed successively with water (20 mL) and saturated sodium chloride aqueous solution (20 mL), dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 10% B). The eluent was collected and concentrated under reduced pressure to give methyl 2-(((2R,3S,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)acetate (compound 2-7,800 mg, crude product).

[0315] MS:m / z 317.02 [M+H] + .

[0316] 1 HNMR(400MHz,DMSO-d6)δ11.35(s,1H),7.89–7.83(m,1H),5.90(d,J=5.4Hz,1H),5.63(dd,J=8.1,2.8Hz,1H), 5.22(s,2H),4.37–4.18(m,2H),4.14(t,J=4.5Hz,1H),4.06(t,J=5.2Hz,1H),3.62(s,3H),3.61–3.53(m,2H).

[0317] Step 7: Synthesis of 2-(((2R,3S,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compounds 2-8)

[0318] Methyl 2-(((2R,3S,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)acetate (compound 2-7, 2 g, 6.3 mmol, 1.0 eq) was dissolved in MeOH (20 mL), and propargylamine (3.5 g, 63 mmol, 10 eq) was added. The mixture was heated to 65 °C and stirred for 3 h. TLC showed that the reaction was complete. The reaction solution was concentrated to obtain the crude product, which was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 10% B). The eluent was collected and concentrated under reduced pressure to obtain 2-(((2R,3S,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 2-8, 900 mg, three-step yield: 45%).

[0319] 1 HNMR (400MHz, DMSO-d6) δ11.36(s,1H),8.35(t,J=5.7Hz,1H),7.94(d,J=8.1Hz,1H),5.83(d,J=3.4Hz,1H),5.62(d,J=8.1Hz,1H),5.40(d ,J=6.7Hz,1H),5.17(t,J=5.0Hz,1H),4.20–3.97(m,4H),3.97–3.86(m,3H),3.79–3.66(m,1H),3.66–3.52(m,1H),3.13(t,J=2.5Hz,1H).

[0320] Step 8: Synthesis of 2-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-((1-eicosyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compounds 2-9)

[0321] 2-(((2R,3S,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 2-8, 400 mg, 1.0 eq, 1.2 mmol) was dissolved in a mixture of THF (10 mL) and water (2 mL). The system was cooled to 0 °C under nitrogen protection, and then 1-azidododecane (compound 2-1, 621 mg, 1.5 eq, 1.8 mmol) was added, followed by copper sulfate (94 mg, 0.5 eq, 0.6 mmol) and sodium vitamin C (350 mg, 1.5 eq, 1.8 mmol). The system was brought to room temperature and stirred for 1 h. TLC showed that the reaction was basically complete. The reaction solution was poured into a saturated NaHCO3 solution (10 mL), and a solid precipitated out. The solid was filtered, and the filter cake was dissolved in 20 mL of a mixed solvent (dichloromethane:methanol = 10:1). The solution was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 10% B). The eluent was collected and concentrated under reduced pressure to give 2-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-((1-dococosyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 2-9, 394 mg, yield: 48%).

[0322] 1 H NMR(400MHz, DMSO-d6)δ11.36(d,J=2.2Hz,1H),8.44(t,J=5.9Hz,1H),7.96–7.90(m,2H),5.83 (d,J=3.4Hz,1H),5.61(dd,J=8.1,2.2Hz,1H),5.41(d,J=6.7Hz,1H),5.17(t,J=5.0Hz,1H),4.3 7–4.27(m,4H),4.12–4.04(m,2H),4.02–3.98(m,1H),3.91–3.86(m,1H),3.69(s,1H),3.59(d, J=4.5Hz,1H),3.17(d,J=5.3Hz,1H),1.82–1.72(m,2H),1.27–1.20(m,38H),0.89–0.82(m,3H).

[0323] Step 9: Synthesis of 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-((1-eicosyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 2-10)

[0324] Pretreatment: 2-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-((1-docodecyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 2-9, 300 mg, 0.43 mmol, 1.0 eq) was dissolved in ultradry pyridine (5 mL), and then concentrated under reduced pressure. This process was repeated three times.

[0325] Under ice bath conditions, pretreated 2-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-((1-dococoyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compounds 2-9) was dissolved in ultradry pyridine (3 mL), and then 4,4'-dimethoxytriphenylchloromethane (220 mg, 0.65 mmol, 1.5 eq) was added, purging nitrogen three times. The system was slowly heated to 25 °C and stirred at room temperature for 6 h. TLC showed that the reaction was basically complete. The reaction solution was concentrated and dried. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 7% B). The eluent was collected and concentrated under reduced pressure to give 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-((1-eicosyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 2-10, 290 mg, yield: 68%).

[0326] 1HNMR (400MHz, DMSO-d6) δ11.43(d,J=2.2Hz,1H),8.46(t,J=5.9Hz,1H),7.93(s,1H),7.74(d, J=8.1Hz,1H),7.44–7.37(m,2H),7.37–7.22(m,7H),6.95–6.88(m,4H),5.84(d,J=2.1Hz,1H), 5.49(d,J=7.9Hz,1H),5.28(dd,J=8.1,2.2Hz,1H),4.44–4.21(m,6H),4.13–4.02(m,3H),3.76 (s, 6H), 3.31 (d, J = 21.4Hz, 2H), 1.78 (t, J = 7.2Hz, 2H), 1.28–1.20 (m, 38H), 0.91–0.83 (m, 3H).

[0327] Step 10: Synthesis of (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(((1-eicosyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N2U)

[0328] Pretreatment: 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-((1-dococosyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 2-10, 290 mg, 1 eq, 0.29 mmol) was dissolved in anhydrous pyridine (10 mL) and concentrated under reduced pressure to remove trace amounts of water.

[0329] Pretreated 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-((1-eicosyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 2-10) was dissolved in dichloromethane (18 mL), anhydrous magnesium sulfate (2.3 g) was added, and nitrogen was used for purging. The mixture was cooled to 0°C in an ice bath, and then a solution of N,N-diisopropylethylamine (302 mg, 2.34 mmol, 8 eq) and N-methylimidazole (12 mg, 0.15 mmol, 0.5 eq) in dichloromethane (1 mL) was added. After stirring for 5 min, a solution of N,N-diisopropylphosphonamide (2-cyanoethyl) ester (553 mg, 8 eq, 2.34 mmol) in dichloromethane (2.5 mL) was slowly added dropwise. After the addition was complete, the temperature was raised to 23°C and stirred for 2 h. The reaction solution was filtered, and the filter cake was washed with dichloromethane (20 mL). The filtrate was poured into an ice-cold saturated sodium bicarbonate aqueous solution (60 mL), and extracted with dichloromethane (20 mL * 3). The organic phase was then washed with saturated sodium bicarbonate aqueous solution (20 mL * 4) and saturated sodium chloride solution (20 mL). The solution was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The solution was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 6% B). The eluent was collected and purified under reduced pressure. After concentration, (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(((1-eicosyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N2U, 210 mg, yield: 60.3%) was obtained.

[0330] 1H NMR (400MHz, DMSO-d6) δ11.40(s,1H),8.11(t,J=6.0Hz,1H),7.86(d,J=8.8Hz,1H),7.77–7.74(m,1H),7.40–7.21(m, 9H),6.90–6.86(m,4H),5.88(dd,J=7.4,2.8Hz,1H),5.27(d,J=8.0Hz,1H),4.45–4.11(m,9H),3.81–3.75(m,1H),3.73 (d,J=2.4Hz,6H),3.70–3.58(m,1H),3.52–3.43(m,2H),3.38–3.34(m,1H),3.28–3.24(m,1H),2.75–2.71(m,1H),2.61 –2.58(m,1H),1.78–1.72(m,2H),1.22–1.21(m,38H),1.10–1.02(m,9H),0.91(d,J=6.8Hz,3H),0.85(t,J=6.6Hz,3H).

[0331] 31 P NMR(162MHz,DMSO-d6)δ149.59,148.27.

[0332] Example 3

[0333] Step 1: Synthesis of 3-benzoyl-1-((6aR,8R,9R,9aR)-2,2,4,4-tetraisopropyl-9-(prop-2-yn-1-yloxy)tetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilaoctane-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 3-1)

[0334] Under ice bath conditions, 3-benzoyl-1-((6aR,8R,9S,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilicyclooctane-8-yl)pyrimidin-2,4(1H,3H)-dione (compound 2-4, 2.0 g, 3.39 mmol, 1.0 eq) was dissolved in a mixed solvent of propargyl bromide (10 mL) and toluene (10 mL). After purging with nitrogen, tetrabutylammonium iodide (626 mg, 1.69 mmol, 0.5 eq) was added, followed by slow dropwise addition of NaOH aqueous solution (12 mL, 60% w / v). The reaction was carried out at 0 °C for 5 min. TLC showed that the reaction was essentially complete. The extract was poured into water (60 mL), extracted with dichloromethane (120 mL), washed with saturated sodium chloride aqueous solution (60 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 12% B). The eluent was collected and concentrated under reduced pressure to obtain 3-benzoyl-1-((6aR,8R,9R,9aR)-2,2,4,4-tetraisopropyl-9-(prop-2-yn-1-yloxy)tetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilacino-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 3-1, 1.2 g, yield: 55%).

[0335] MS:m / z 629.27[M+H] + .

[0336] 1 HNMR(400MHz,DMSO-d6)δ8.04–7.96(m,2H),7.88–7.76(m,2H),7.61(t,J=7.7Hz,2H),5.83(d,J=8.2Hz,1H),5.64(s,1H), 4.41(d,J=2.4Hz,2H),4.32(d,J=8.1Hz,2H),4.22–4.15(m,1H),4.03–3.92(m,2H),3.45–3.41(m,1H),1.08–1.00(m,28H).

[0337] Step 2: Synthesis of 3-benzoyl-1-((2R,3R,4R,5R)-4-hydroxy-5-(hydroxymethyl)-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 3-2)

[0338] Under ice bath conditions, tetrabutylammonium fluoride (4.8 mL, 4.78 mmol, 2.5 eq, 1 M in THF) was added dropwise to a tetrahydrofuran (12 mL) solution of 3-benzoyl-1-((6aR,8R,9R,9aR)-2,2,4,4-tetraisopropyl-9-(prop-2-yn-1-oxy)tetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiosilacinoin-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 3-1, 1.2 g, 1.91 mmol, 1.0 eq). After the addition was complete, the temperature was slowly raised to 25 °C and stirred for 1 h. TLC showed that the reaction was complete. The reaction solution was concentrated and dried to obtain a crude product, which was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 6% B). The eluent was collected and concentrated under reduced pressure to give 3-benzoyl-1-((2R,3R,4R,5R)-4-hydroxy-5-(hydroxymethyl)-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 3-2, 500 mg, yield: 84.2%).

[0339] MS:m / z 387.06 [M+H] +

[0340] 1 HNMR (400MHz, DMSO-d6) δ8.23(d,J=8.3Hz,1H),8.01–7.95(m,2H),7.83–7.77(m,1H),7.62(t,J=7.8Hz,2H),5.96(d ,J=8.2Hz,1H),5.86–5.84(m,1H),5.30(s,2H),4.35–4.17(m,5H),3.73(s,1H),3.63(s,1H),3.49(d,J=4.7Hz,1H).

[0341] Step 3: Synthesis of 1-((2R,3R,4R,5R)-4-hydroxy-5-(hydroxymethyl)-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 3-3)

[0342] 3-Benzoyl-1-((2R,3R,4R,5R)-4-hydroxy-5-(hydroxymethyl)-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 3-2, 630 mg, 1.63 mmol, 1.0 eq) was dissolved in ammonia-methanol (7 M, 10 mL) and stirred at room temperature for 2 h. TLC and LCMS showed that the reaction was complete. The reaction solution was concentrated to obtain the crude product, which was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 7% B). The eluent was collected and concentrated under reduced pressure to give 1-((2R,3R,4R,5R)-4-hydroxy-5-(hydroxymethyl)-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 3-3,421 mg, yield: 91%).

[0343] MS:m / z 283.08 [M+H] + .

[0344] 1 HNMR (400MHz, DMSO-d6) δ11.36(d,J=2.2Hz,1H),7.93(d,J=8.1Hz,1H),5.88(d,J=5.3Hz,1H),5.66(dd,J=8.1,2.1Hz,1H),5.25(d,J=5.6Hz, 1H),5.17(t,J=4.9Hz,1H),4.27(qd,J=15.9,2.4Hz,2H),4.18–4.07(m,2H),3.87(q,J=3.2Hz,1H),3.70–3.52(m,2H),3.44(t,J=2.4Hz,1H).

[0345] Step 4: Synthesis of 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compounds 3-4)

[0346] Pretreatment: 1-((2R,3R,4R,5R)-4-hydroxy-5-(hydroxymethyl)-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 3-3) was dissolved in ultradry pyridine (10 mL), concentrated and dried under reduced pressure, and repeated 3 times.

[0347] Under ice bath conditions, 4,4'-dimethoxytriphenylchloromethane (605 mg, 1.79 mmol, 1.2 eq) was added to a pretreated ultradry pyridine solution (5 mL) of 1-((2R,3R,4R,5R)-4-hydroxy-5-(hydroxymethyl)-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 3-3, 420 mg, 1.49 mmol, 1.0 eq), and nitrogen was purged three times. The reaction solution was slowly heated to 25 °C and stirred at room temperature for 16 h. TLC showed that the reaction was complete. The reaction solution was then cooled to 0 °C in an ice-water bath, and the reaction was quenched by slowly adding methanol (1 mL). The reaction solution was concentrated to obtain a crude product, which was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 7% B). The eluent was collected and concentrated under reduced pressure to give 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 3-4, 705 mg, yield: 81%).

[0348] 1 HNMR(400MHz,DMSO-d6)δ11.41(s,1H),7.74(d,J=8.1Hz,1H),7.40–7.31(m,4 H),7.29–7.21(m,5H),6.95–6.86(m,4H),5.85(d,J=4.4Hz,1H),5.31(dd,J=2 2.5,7.2Hz,2H),4.41–4.32(m,2H),4.31–4.24(m,1H),4.18(t,J=4.8Hz,1H), 3.99(d,J=4.0Hz,1H),3.74(s,6H),3.51(t,J=2.4Hz,1H),3.31–3.17(m,2H).

[0349] Step 5: Synthesis of 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-((1-eicosyl-1H-1,2,3-triazol-4-yl)methoxy)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compounds 3-5)

[0350] 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 3-4, 700 mg, 1.2 mmol, 1.0 eq) was dissolved in tetrahydrofuran (10 mL) and water (2 mL). The system was cooled to 0 °C under nitrogen protection. 1-Azide docosane (compound 2-1, 631 mg, 1.8 mmol, 1.5 eq) was added to the reaction solution, followed by copper sulfate (96 mg, 0.6 mmol, 0.5 eq) and sodium vitamin C (178 mg, 0.9 mmol, 0.75 eq). The system was then brought to room temperature and stirred for 2 h. TLC showed the reaction was complete. The reaction solution was poured into a saturated NaHCO3 solution (10 mL), extracted with dichloromethane (30 mL), and the organic phase was washed with a saturated sodium chloride solution (10 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated (300 mbar, 35 °C) to obtain the crude product. The crude product was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 4% B). The eluent was collected and concentrated under reduced pressure to obtain 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-((1-eicosyl-1H-1,2,3-triazol-4-yl)methoxy)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 3-5, 762 mg, yield: 68%).

[0351] 1 HNMR (400MHz, DMSO-d6) δ11.37(s,1H),8.08(s,1H),7.67(d,J=8.1Hz,1H),7.40–7. 19(m,9H),6.96–6.85(m,4H),5.86(d,J=3.9Hz,1H),5.30–5.19(m,2H),4.74(s,2H) ,4.27(dt,J=12.7,6.6Hz,3H),4.10(t,J=4.6Hz,1H),4.03–3.94(m,1H),3.74(s,6H ),3.31–3.17(m,2H),1.77(q,J=7.3Hz,2H),1.33–1.13(m,38H),0.94–0.78(m,3H).

[0352] Step 6: Synthesis of (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-((1-eicosyl-1H-1,2,3-triazol-4-yl)methoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N3U)

[0353] Pretreatment: 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 3-5, 300 mg, 0.32 mmol, 1 eq) was dissolved in ultradry pyridine (10 mL) and concentrated under reduced pressure to remove trace amounts of water.

[0354] Pretreated 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compounds 3-5) was dissolved in dichloromethane (18 mL), anhydrous magnesium sulfate (2.4 g) was added, nitrogen was added, and then N,N-diisopropylethylamine (332 mL) was added. A solution of N,N-diisopropylphosphonamide (2-cyanoethyl) ester (606 mg, 2.56 mmol, 8 eq) in dichloromethane (1 mL) was added dropwise. The mixture was purged with nitrogen and cooled to an ice bath. After stirring for 5 min, a solution of N,N-diisopropylphosphonamide (2-cyanoethyl) ester (606 mg, 2.56 mmol, 8 eq) in dichloromethane (3 mL) was slowly added dropwise. After the addition was complete, the temperature was raised to 23 °C and stirred for 2 h. The reaction solution was filtered, and the filter cake was washed with dichloromethane (20 mL). The filtrate was poured into a saturated sodium bicarbonate aqueous solution (60 mL), extracted with dichloromethane (20 mL * 3), and then washed with a saturated sodium bicarbonate aqueous solution (20 mL * 4) and a saturated sodium chloride solution (20 mL). The solution was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure and subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 45% B). The eluent was collected and concentrated under reduced pressure to give (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-((1-dococoyl-1H-1,2,3-triazol-4-yl)methoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N3U, 180 mg, yield: 49.5%).

[0355] 1H NMR (400MHz, DMSO-d6) δ11.38(s,1H),8.01(d,J=13.4Hz,1H),7.74–7.68(m,1H),7.38–7.21(m,9H),6.92–6.87(m ,4H),5.87(t,J=3.6Hz,1H),5.25–5.19(m,1H),4.73–4.71(m,2H),4.53–4.38(m,1H),4.32–4.27(m,3H),4.15–4.0 7(m,1H),3.82–3.77(m,1H),3.74(d,J=2.8Hz,6H),3.66–3.46(m,3H),3.29–3.24(m,2H),2.76–2.72(m,1H),2.66 –2.58(m,1H),1.80–1.73(m,2H),1.25–1.20(m,38H),1.13–1.04(m,9H),0.94(d,J=6.6Hz,3H),0.87–0.82(m,3H).

[0356] 31 P NMR(162MHz,DMSO-d6)δ149.28,148.83.

[0357] Example 4

[0358] Step 1: Synthesis of 2-(eicosicoalkoxy)isoindoline-1,3-dione (compound 4-1)

[0359] At room temperature, N-hydroxyphthalimide (3.14 g, 19.25 mmol, 1.5 eq) and potassium carbonate (2.66 g, 19.25 mmol, 1.5 eq) were added sequentially to a solution of 1-bromodocosahexadecane (compound 1-1, 5 g, 12.8 mmol, 1.0 eq) in N,N-dimethylformamide (50 mL). The reaction mixture was heated to 80 °C and stirred for 4 hours. TLC showed that the reaction was complete. The reaction mixture was poured into water (400 mL) to form a suspension. The suspension was extracted with n-heptane (500 mL) three times until no product was found in the aqueous phase. The organic phase was collected, concentrated, and dried to give 2-(dococoyloxy)isoindoline-1,3-dione (compound 4-1, 5.2 g, yield: 86%).

[0360] 1HNMR (400MHz, CDCl3) δ7.88 (dd, J=5.4, 3.1Hz, 2H), 7.78 (dd, J=5.5, 3.1Hz, 2H), 4.24 (t ,J=6.8Hz,2H),1.87–1.78(m,2H),1.56–1.47(m,2H),1.29(s,36H),0.94–0.89(m,3H).

[0361] Step 2: Synthesis of O-dodecylhydroxylamine (compound 4-2)

[0362] At room temperature, hydrazine hydrate (425 mg, 8.48 mmol, 2.0 eq) was added dropwise to a suspension of 2-(dococarboxy)isoindoline-1,3-dione (compound 4-1, 2.0 g, 4.24 mmol, 1.0 eq) in anhydrous ethanol (40 mL), and the mixture was stirred at this temperature for 2 hours. TLC showed that the reaction was complete. The reaction solution was concentrated to obtain a crude product, which was subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 3% B). The eluent was collected and concentrated under reduced pressure to give O-dococarboxyhydroxylamine (compound 4-2, 941 mg, yield: 65%).

[0363] 1 HNMR (400MHz, CDCl3) δ5.27(s,2H),3.58(t,J=6.7Hz,2H),1.54–1.41(m,4H),1.26–1.17(m,36H),0.81(t,J=6.7Hz,3H).

[0364] Step 3: Synthesis of 3-(((6aR,8R,9R,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)propionitrile (compound 4-3)

[0365] At 25°C, acrylonitrile (359.26 mg, 6.77 mmol, 20 eq.) and cesium carbonate (110.29 mg, 0.339 mmol, 1 eq.) were added to a tert-butanol (2 mL) solution of 3-benzoyl-1-((6aR,8R,9S,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilylonoctane-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 2-4, 0.2 g, 0.339 mmol, 1 eq.). The reaction mixture was stirred at 25°C for 4 hours. The reaction was monitored by LCMS until it ended. The reaction solution was filtered, and the filter cake was washed with dichloromethane (3 mL * 2). The filtrate was collected, concentrated under reduced pressure, and then subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 25% B). The eluent was collected and concentrated under reduced pressure to give 3-(((6aR,8R,9R,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)propionitrile (compound 4-3, 165 mg, yield 76%).

[0366] MS:m / z 644.31[M+H] + .

[0367] 1 H NMR (400MHz, CDCl3) δ8.05(d,J=8.3Hz,1H),7.98(d,J=7.6Hz,2H),7.71(t,J=7.5Hz,1H),7.56(t,J=7.6Hz,2H),5. 85(d,J=8.2Hz,1H),5.74(s,1H),4.36–4.21(m,3H),4.11–3.92(m,4H),2.66(t,J=6.3Hz,2H),1.19–1.04(m,28H).

[0368] Step 4: Synthesis of 1-((6aR,8R,9R,9aR)-9-(3-aminopropoxy)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilaindol-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 4-4)

[0369] Raney-Ni (750 mg) was added to an ammonia-methanol (60 mL) solution of compound 3-(((6aR,8R,9R,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)propionitrile (compound 4-3, 1.5 g, 2.33 mmol, 1 eq.) at 25 °C. The reaction mixture was purged with H2 three times and then stirred at 25 °C for 3 hours. The reaction was monitored by LCMS until complete. The reaction solution was filtered, and the filter cake was washed with methanol (10 mL * 3). The filtrate was concentrated under reduced pressure to obtain 1-((6aR,8R,9R,9aR)-9-(3-aminopropoxy)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilaindol-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 4-4, 1.35 g, crude product), which was directly used for the next reaction.

[0370] MS:m / z 544.30[M+H] + .

[0371] Step 5: Synthesis of 1-(3-(((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)propyl)-3-(eicosicoalkoxy)urea (compounds 4-5)

[0372] At room temperature, O-eicosylhydroxylamine (compound 4-2, 1.02 g, 2.34 mmol, 1 eq.) was added to a solution of compound 1-((6aR,8R,9R,9aR)-9-(3-aminopropoxy)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiazine-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 4-4, 1.27 g, 2.34 mmol, 1 eq.) in N,N-dimethylformamide (33 mL). The reaction mixture was then purged with nitrogen three times, and the solution was heated to 80 °C and stirred for 16 hours. TLC showed complete reaction of the starting materials, and the reaction solution was directly concentrated under reduced pressure. Normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 3% B) was performed. The eluent was collected and concentrated under reduced pressure to give 1-(3-(((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilyl-9-yl)oxy)propyl)-3-(eicosicoalkoxy)urea (compound 4-5, 1.21 g, yield: 57%).

[0373] 1 H NMR (400MHz, DMSO-d6) δ11.45–11.38(m,1H),8.95(s,1H),7.67(d,J=8.1Hz,1H),6.60(t,J=5.9Hz,1H), 5.60(s,1H),5.54(dd,J=8.1,2.2Hz,1H),4.28–4.23(m,1H),4.15(d,J=13.2Hz,1H),4.04(d,J=4.7Hz,1H ),4.01–3.90(m,2H),3.82–3.75(m,1H),3.74–3.68(m,1H),3.64(t,J=6.8Hz,2H),3.18(q,J=6.7Hz,2H), 1.72(p,J=6.6Hz,2H),1.60–1.50(m,2H),1.29–1.21(m,38H),1.11–0.98(m,28H),0.87(t,J=6.7Hz,3H).

[0374] Step 6: Synthesis of 1-(3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propyl)-3-(eicosicoalkoxy)urea (compounds 4-6)

[0375] Under ice bath conditions, tetrabutylammonium fluoride (0.25 mL, 0.25 mmol, 2.5 eq, 1 M) was added dropwise to a 2 mL solution of tetrahydrofuran containing 1-(3-(((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilyl-9-yl)oxy)propyl)-3-(eicosicoalkoxy)urea (compound 4-5, 90 mg, 0.099 mmol, 1.0 eq). After the addition was complete, the temperature was slowly raised to 25 °C and the mixture was stirred for 1 h. TLC showed that the reaction was complete. The reaction solution was concentrated under reduced pressure to remove the solvent. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was collected and concentrated under reduced pressure to give 1-(3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propyl)-3-(eicosethoxy)urea (compound 4-6, 50 mg, yield: 75.7%).

[0376] 1 H NMR (400MHz, DMSO-d6) δ11.35(s,1H),8.97(s,1H),7.96(d,J=8.1Hz,1H),6.74(t,J=6.0 Hz,1H),5.85(d,J=4.9Hz,1H),5.68–5.62(m,1H),5.20–5.09(m,2H),4.12(q,J=5.2Hz,1H ),3.92–3.85(m,2H),3.70–3.62(m,3H),3.61–3.49(m,3H),3.25–3.15(m,1H),3.14–3.06 (m,1H),1.71–1.64(m,2H),1.60–1.52(m,2H),1.31–1.22(m,38H),0.87(t,J=6.5Hz,3H).

[0377] Step 7: Synthesis of (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(3-(3-(eicosicoalkoxy)ureo)propoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compounds 4-7)

[0378] 1-(3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propyl)-3-(eicosicoalkoxy)urea (compound 4-6, 478 mg, 0.71 mmol, 1.0 eq) was dissolved in anhydrous pyridine (5 mL * 2), then concentrated under reduced pressure to remove residual water. At 0 °C, the pretreated 1-(3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4- 4,4'-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propyl)-3-(dococoyloxy)urea (compound 4-6, 478 mg, 0.71 mmol, 1.0 eq) was dissolved in pyridine (10 mL), and then 4,4'-dimethoxytriphenylchloromethane (361 mg, 1.07 mmol, 1.5 eq) was added. After the addition was complete, the reaction system temperature was raised to 25 °C and stirring was continued for 7 hours. When TLC monitoring showed that there was a remaining starting material, 4,4'-dimethoxytriphenylchloromethane (120 mg, 0.36 mmol, 0.5 eq) was added, and stirring was continued for 16 hours. The reaction was monitored by TLC until complete. Methanol was slowly added dropwise to the reaction solution at 0°C. The solution was then concentrated under reduced pressure to remove pyridine. The solvent was removed by further concentration under reduced pressure. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was collected and concentrated under reduced pressure to give (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(3-(3-(eicosicoalkoxy)ureo)propoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound 4-7, 390 mg, yield: 56%).

[0379] MS:m / z 971.61[M+H] + .

[0380] 1H NMR (400MHz, DMSO-d6) δ11.38(s,1H),8.95(s,1H),7.73(d,J=8.1Hz,1H),7.41–7.36(m,2H),7.32(t,J=7.6Hz,2H) ,7.25(dt,J=8.1,2.8Hz,5H),6.93–6.87(m,4H),6.71(t,J=6.0Hz,1H),5.79(d,J=3.4Hz,1H),5.28(dd,J=8.0,1.8 Hz,1H),5.20(d,J=6.7Hz,1H),4.19(q,J=6.3Hz,1H),3.97(s,1H),3.93–3.88(m,1H),3.74(s,6H),3.62(q,J=7.8, 7.3Hz, 4H), 3.31–3.06 (m, 4H), 1.68 (t, J = 6.3Hz, 2H), 1.52 (d, J = 7.1Hz, 2H), 1.25–1.18 (m, 38H), 0.89–0.80 (m, 3H).

[0381] Step 8: Synthesis of (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(3-(3-(eicosicoalkoxy)ureo)propoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N4U)

[0382] Pretreatment: 1-(3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)propyl)-3-(eicosicoalkoxy)urea (compound 4-7, 55 mg, 0.057 mmol, 1.0 eq) was azeotropically dried with toluene (0.5 mL * 2) to remove residual moisture.

[0383] 1-Hydrotetrazole (7.9 mg, 0.113 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (225 μL) under nitrogen protection at 25 °C. Bis(diisopropylamino)(2-cyanoethoxy)phosphine (34 mg, 0.113 mmol, 2.0 eq) was added to the reaction solution under nitrogen protection at 25 °C, and the reaction was carried out at 28–30 °C for 1 hour. Under nitrogen protection, pretreated 1-(3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)propyl)-3-(eicosicoalkoxy)urea (compound 4-7, 55 mg, 0.057 mmol, 1.0 eq) and ultradry N,N-diisopropylethylamine (14.7 mg, 0.113 mmol, 2.0 eq) were dissolved in dichloromethane (0.4 mL) and added to the reaction solution. The reaction was continued for 2 hours. The reaction was monitored by TLC until it was complete. The reaction solution was directly subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was collected and concentrated under reduced pressure to give (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(3-(3-(eicosicoalkoxy)ureo)propoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N4U, 38 mg, yield: 57%).

[0384] MS:m / z 1170.71[M+H] + .

[0385] 1H NMR(400MHz, DMSO-d6)δ11.38(s,1H),8.92(d,J=6.5Hz,1H),7.83–7.75(m,1H),7.42–7.20(m,9H),6.93–6.85(m,4H),6 .64–6.59(m,1H),5.82–5.78(m,1H),5.35–5.19(m,1H),4.47–4.33(m,1H),4.14–4.03(m,2H),3.83–3.76(m,1H),3.74( d,J=2.7Hz,6H),3.68–3.43(m,7H),3.39–3.34(m,2H),3.16–3.07(m,2H),2.78(t,J=5.9Hz,1H),2.65–2.57(m,1H),1.7 3–1.62(m,2H),1.57–1.47(m,2H),1.22(d,J=3.5Hz,38H),1.15–1.07(m,9H),0.96(d,J=6.7Hz,3H),0.87–0.82(m,3H).

[0386] 31 P NMR(162MHz,DMSO-d6)δ149.13,148.56.

[0387] Example 5

[0388] Step 1: Synthesis of methyl 3-((((6aR,8R,9R,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl)oxy)propionate (compound 5-1)

[0389] At room temperature, 3-benzoyl-1-((6aR,8R,9R,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 2-4,8 g, 13.56 mmol, 1.0 eq) was dissolved in tert-butanol (80 mL). Methyl acrylate (23.3 g, 271.2 mmol, 20 eq) and Cs₂CO₃ (4.42 g, 13.56 mmol, 1.0 eq) were added sequentially to the stirred solution. The reaction mixture was heated to 30 °C and stirred for 48 hours. TLC showed that the reaction was basically complete. The reaction solution was poured into water (100 mL), extracted with ethyl acetate (200 mL), and the organic phase was washed with saturated sodium chloride aqueous solution (100 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 20% B). The eluent was collected and concentrated under reduced pressure to give methyl 3-((((6aR,8R,9R,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl)oxy)propionate (compound 5-1,6 g, yield: 65.5%).

[0390] MS:m / z 677.34[M+H] +

[0391] 1 HNMR (400MHz, DMSO-d6) δ8.06–8.00(m,2H),7.88–7.78(m,2H),7.63(t,J=7.9Hz,2H),5.85(d,J=8.2Hz,1H),5.64(s,1H) ,4.27(dd,J=9.3,4.6Hz,1H),4.23–4.15(m,2H),4.02–3.89(m,4H),3.57(s,3H),2.62–2.56(m,2H),1.11–1.00(m,28H).

[0392] Step 2: Synthesis of methyl 3-(((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)propionate (compound 5-2)

[0393] Under ice bath conditions, K₂CO₃ (1.22 g, 8.8 mmol, 2.0 eq) was added to a MeOH (30 mL) solution of methyl 3-((((6aR,8R,9R,9aR)-8-(3-benzoyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl)oxy)propionate (compound 5-1, 3.0 g, 4.4 mmol, 1.0 eq) and stirred at room temperature for 2 h. TLC showed the reaction of the starting material. Completely dilute the reaction solution with ethyl acetate (100 mL) and pour it into water (50 mL). Shake and extract. Wash the organic phase with saturated sodium chloride solution (50 mL), dry with anhydrous magnesium sulfate, filter, and concentrate the filtrate under reduced pressure to obtain methyl 3-(((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)propionate (compound 5-2, crude product), which can be used directly in the next step without purification.

[0394] MS:m / z 573.20[M+H] + .

[0395] Step 3: Synthesis of methyl 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propionate (compound 5-3)

[0396] Under ice bath conditions, methyl 3-(((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)propionate (compound 5-2, crude) was added dropwise to a THF (30 mL) solution. After the addition was complete, the temperature was slowly raised to 25 °C, and stirring was continued for 1 h. TLC showed that the reaction was complete. The reaction solution was concentrated to obtain the crude product. The crude product was subjected to normal-phase column chromatography (silica gel, mobile phase A: ethyl acetate, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was collected and concentrated under reduced pressure to give methyl 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propionate (compound 5-3, 907 mg, two-step yield: 62%).

[0397] 1 HNMR (400MHz, DMSO-d6) δ11.35(s,1H),7.94(d,J=8.1Hz,1H),5.84(d,J=5.1Hz,1H),5.67(d,J=8.1Hz,1H),5.16(t,J=5.1Hz,1H),5. 05(d,J=5.4Hz,1H),4.16–4.01(m,2H),3.94(t,J=5.1Hz,1H),3.88–3.73(m,3H),3.68–3.62(m,1H),3.59(s,3H),2.64–2.57(m,2H).

[0398] Step 4: Synthesis of 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propionic acid (compound 5-4)

[0399] Under ice bath conditions, KOH (460 mg, 8.22 mmol, 3.0 eq) was added to a mixture of methyl 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propionate (compound 5-3, 904 mg, 2.74 mmol, 1.0 eq) in THF (10 mL) and pure water (5 mL). The reaction mixture was slowly heated to 25 °C and stirred for 1 h. TLC showed that the reaction was complete. The reaction mixture was poured into water (10 mL) and extracted with ethyl acetate to remove lipid-soluble impurities. The aqueous phase was collected and the pH was adjusted to 6-7 with 1 N hydrochloric acid. After freeze-drying for 18 hours, 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propionic acid (compound 5-4, crude product) was obtained and proceeded directly to the next step without further purification.

[0400] Step 5: Synthesis of 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-(eicosicoalkoxy)propionamide (compound 5-5)

[0401] At room temperature, a 20 mL anhydrous dichloromethane solution of 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propionic acid (compound 5-4, crude) was slowly added dropwise to O-docosahexadecylhydroxylamine (compound 4-2, 1.12 g, 3.3 mmol, 1.2 e e). The reaction was carried out in a 10 mL solution of dichloromethane containing q), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (525.3 mg, 2.74 mmol, 1.0 eq), 1-hydroxybenzotriazole (370.2 mg, 2.74 mmol, 1.0 eq), and N,N-diisopropylethylamine (1.06 g, 8.22 mmol, 3.0 eq), and stirred at room temperature for 17 hours. TLC showed that the reaction was basically complete. The reaction solution was concentrated to obtain a crude product, which was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 10% B). The eluent was collected and concentrated under reduced pressure to obtain 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-(eicosicooxy)propionamide (compound 5-5, 790 mg, two-step yield: 45%).

[0402] 1 HNMR(400MHz,DMSO-d6)δ11.35(d,J=2.2Hz,1H),10.92(s,1H),7.94(d,J=8.1Hz,1H) ,5.84(d,J=5.1Hz,1H),5.66(dd,J=8.1,2.2Hz,1H),5.17(t,J=5.0Hz,1H),5.09(d,J= 5.3Hz,1H),4.16(q,J=4.8Hz,1H),3.95(t,J=5.0Hz,1H),3.89–3.83(m,1H),3.80–3. 53(m,7H),2.26(t,J=6.2Hz,2H),1.60–1.46(m,2H),1.25(s,38H),0.93–0.80(m,3H).

[0403] Step 6: Synthesis of 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(eicosicoalkoxy)propionamide (compounds 5-6)

[0404] Under ice bath conditions, 4,4'-dimethoxytriphenylchloromethane (559 mg, 1.65 mmol, 1.5 eq) was added to an ultra-dry pyridine (7 mL) solution of 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-(eicosukekoxy)propionamide (compound 5-5, 700 mg, 1.1 mmol, 1.0 eq), and nitrogen was purged three times. The system was slowly heated to 25 °C and stirred overnight at room temperature for 16 hours. TLC showed that the reaction was essentially complete. The reaction solution was then cooled to 0 °C, and the reaction was quenched by slowly adding 0.5 mL of methanol. The reaction solution was then concentrated to obtain a crude product, which was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was collected and concentrated under reduced pressure to obtain 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(eicosicoalkoxy)propionamide (compounds 5-6, 773 mg, yield: 75%).

[0405] 1 HNMR(400MHz,DMSO-d6)δ11.40(s,1H),10.90(s,1H),7.73(d,J=8.1Hz,1H),7.447.31(m,4H),7.3 0–7.23(m,5H),6.92(d,J=8.4Hz,4H),5.80(d,J=3.5Hz,1H),5.31(d,J=8.1Hz,1H),5.18(d,J=6.2H z,1H),4.24(d,J=5.8Hz,1H),3.97(ddd,J=13.8,7.6,3.7Hz,2H),3.85–3.69(m,10H),3.34–3.20( m,2H),2.28(t,J=6.3Hz,2H),1.51(q,J=6.9Hz,2H),1.25(d,J=4.2Hz,38H),0.87(t,J=6.7Hz,3H).

[0406] Step 7: Synthesis of (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(3-((eicosicoalkoxy)amino)-3-oxopropoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N5U)

[0407] Pretreatment: 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(dococoyloxy)propionamide (compounds 5-6, 300 mg, 1 eq, 0.32 mmol) was dissolved in anhydrous pyridine (10 mL) and concentrated under reduced pressure to remove trace amounts of water.

[0408] Pretreated 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(eicosicoalkoxy)propionamide (compounds 5-6) were dissolved in dichloromethane (18 mL), anhydrous magnesium sulfate (2.4 g) was added, nitrogen was used for purging, and the mixture was cooled to an ice bath. Then, a solution of N,N-diisopropylethylamine (330 mg, 8 eq, 2.55 mmol) and N-methylimidazole (13 mg, 0.5 eq, 0.16 mmol) in dichloromethane (0.5 mL) was added. After stirring for 5 min, a solution of bis(diisopropylamino)(2-cyanoethoxy)phosphine (603 mg, 8 eq, 2.55 mmol) in dichloromethane (1 mL) was slowly added dropwise. After the addition was complete, the temperature was raised to 20 °C and stirred for 2 h. TLC showed that the starting material reacted completely. Filter the reaction solution, wash the filter cake with dichloromethane (30 mL), pour the filtrate into ice-cold saturated sodium bicarbonate aqueous solution (40 mL), shake, separate the organic phase, extract the aqueous phase with dichloromethane (20 mL * 2), combine the organic phases, then wash the organic phase with saturated sodium bicarbonate aqueous solution (30 mL) and saturated sodium chloride solution (30 mL), dry with anhydrous sodium sulfate, filter, and directly perform normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, washing...). Degradation: 0% B to 3% B), the eluent was collected and concentrated under reduced pressure to obtain (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(3-((dococosyloxy)amino)-3-oxopropoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N5U, 170 mg, 47%).

[0409] MS:m / z 1141.68 [M+H] + .

[0410] 1H NMR(400MHz,DMSO-d6)δ11.38(s,1H),10.84(s,1H),7.79–7.73(m,1H),7.40–7.29(m,4H),7.28–7.22(m,5H),6.91–6 .86(m,4H),5.81–5.78(m,1H),5.29–5.22(m,1H),4.44–4.30(m,1H),4.14–4.04(m,2H),3.84–3.76(m,2H),3.73(d,J =2.8Hz,6H),3.72–3.62(m,4H),3.57–3.47(m,2H),3.29–3.25(m,2H),2.77(t,J=5.8Hz,1H),2.62–2.59(m,1H),2.22 (t,J=6.6Hz,2H),1.52–1.44(m,2H),1.23–1.21(m,38H),1.14–1.09(m,9H),0.96(d,J=6.8Hz,3H),0.87–0.83(m,3H).

[0411] 31 P NMR(162MHz,DMSO-d6)δ149.23,148.68.

[0412] Example 6

[0413] Step 1: Synthesis of (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl1H-imidazol-1-carboxylic acid ester (compound 6-1)

[0414] At 25 °C, N,N'-carbonyldiimidazole (2.5 g, 15.41 mmol, 1.5 eq.) was added to a solution of compound 1-((6aR,8R,9R,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilylonoctane-8-yl)pyrimidine-2,4(1H,3H)-dione (compound 2-3,5 g, 10.27 mmol, 1 eq.) in dichloromethane (70 mL). The reaction mixture was stirred at 25 °C for 20 hours. TLC showed that the reaction was complete. The reaction solution was concentrated under reduced pressure and directly subjected to normal-phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 50% B). The eluent was collected and concentrated under reduced pressure to give (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl 1H-imidazol-1-carboxylic acid ester (compound 6-1, 4.65 g, yield: 78%).

[0415] 1 H NMR (400MHz, DMSO-d6) δ11.46(d,J=2.2Hz,1H),8.44–8.41(m,1H),7.72(t,J=1.5Hz,1H),7.67(d,J=8.1Hz,1H),7.15–7.10(m,1H),5.88(d,J=1. 2Hz,1H),5.82(dd,J=5.5,1.3Hz,1H),5.64(dd,J=8.0,2.1Hz,1H),4.81 –4.71(m,1H),4.14–3.97(m,3H),1.10–1.01(m,21H),0.83–0.74(m,7H).

[0416] Step 2: Synthesis of 2-(2-(2-(((((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)carbonyl)amino)ethoxy)ethoxy)acetic acid (compound 6-2)

[0417] To a solution of compound (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl1H-imidazol-1-carboxylic acid ester (compound 6-1,2 g, 3.44 mmol, 1.0 eq.) in N,N-dimethylformamide (20 mL), 2-(2-(2-aminoethoxy)ethoxy)acetic acid (674.29 mg, 4.13 mmol, 1.2 eq.) was added, followed by nitrogen purging three times and stirring at 80 °C for 5 hours. The reaction solution was then directly purified by reverse-phase chromatography (C18, mobile phase A: water (0.1% FA), mobile phase B: acetonitrile; elution gradient: 0% B to 62% B). The eluent was concentrated at room temperature to remove some acetonitrile, and then directly lyophilized to obtain 2-(2-(2-(((((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)carbonyl)amino)ethoxy)ethoxy)acetic acid (compound 6-2, 1.4 g, yield: 48.12%).

[0418] MS:m / z 676.29 [M+H] +

[0419] Step 3: Synthesis of (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-3)

[0420] Under nitrogen protection, N,N-dimethylformamide (25 mL) was added to compound 2-(2-(2-(((((6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)carbonyl)amino)ethoxy)ethoxy)acetic acid (compound 6-2, 1.4 g, 2.07 mmol, 1 eq.). 1-Aminodocoane (compound 10-1, 674.49 mg, 2.07 mmol, 1 eq.), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (397.09 mg, 2.07 mmol, 1 eq.), 1-hydroxybenzotriazole (279.90 mg, 2.07 mmol, 1 eq.), and N,N-diisopropylethylamine (803.16 mg, 6.21 mmol, 3 eq.) were added to the solution, and the reaction mixture was stirred at 35 °C for 22 hours. The reaction was monitored by TLC until complete. The reaction mixture was diluted with water (200 mL) and extracted with ethyl acetate (80 mL * 3). The organic phases were combined and washed with saturated sodium chloride aqueous solution (80 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure and then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 6% B). The eluent was concentrated under reduced pressure to give (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-3, 1.23 g, yield: 60.38%).

[0421] 1H NMR (400MHz, DMSO-d6) δ11.44(s,1H),7.71(d,J=8.1Hz,1H),7.62(t,J=5.6Hz,1H),7.45(t,J=5. 7Hz,1H),5.69–5.66(m,1H),5.62(d,J=8.1Hz,1H),5.34(d,J=5.8Hz,1H),4.57–4.49(m,1H),4.1 3–4.05(m,1H),4.00–3.93(m,1H),3.90–3.81(m,3H),3.62–3.52(m,4H),3.47–3.41(m,2H),3.21 –3.05(m,4H),1.46–1.38(m,2H),1.27–1.22(m,38H),1.10–0.97(m,28H),0.86(t,J=6.9Hz,3H).

[0422] Step 4: Synthesis of (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-4)

[0423] Under ice-water bath conditions, tetrabutylammonium fluoride (764.34 mg, 2.92 mmol, 2.5 eq., 1 M in THF) was added to a tetrahydrofuran (4 mL) solution of compound (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-3, 1.15 g, 1.17 mmol, 1.0 eq.) in 6-trioxadisila-9-yl(2-(2-(eicosila-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-3, 1.15 g, 1.17 mmol, 1.0 eq.). The reaction mixture was stirred at 25 °C for 0.5 h. The reaction was monitored by TLC until complete. The reaction solution was concentrated under reduced pressure and subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to give (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-4, 610 mg, yield: 70.4%).

[0424] 1H NMR (400MHz, DMSO-d6) δ11.37(s,1H),7.93(d,J=8.1Hz,1H),7.65(t,J=6.0Hz,1H),7.36(t,J=5.7H z,1H),5.99(d,J=6.1Hz,1H),5.68(d,J=8.0Hz,1H),5.50(d,J=5.3Hz,1H),5.21(t,J=4.9Hz,1H),5. 04(t,J=5.7Hz,1H),4.25–4.17(m,1H),3.93–3.88(m,1H),3.86(s,2H),3.69–3.62(m,1H),3.60–3.5 3(m,5H),3.46–3.39(m,2H),3.16–3.05(m,4H),1.44–1.38(m,2H),1.25(s,38H),0.89–0.85(m,3H).

[0425] Step 5: Synthesis of (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compounds 6-5)

[0426] Under ice bath conditions, 4,4'-dimethoxytriphenylchloromethane (412 mg, 1.2 mmol, 1.5 eq) was added to an ultra-dry pyridine (6 mL) solution of (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-4, 600 mg, 0.81 mmol, 1.0 eq), and nitrogen was purged three times. The system was slowly heated to 25 °C and stirred for 17 hours. The reaction was monitored by TLC until it was complete, and the reaction solution was cooled to 0 °C and quenched by slow dropwise addition of methanol (0.5 mL). The reaction solution was then concentrated under reduced pressure to obtain a crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 7% B). The eluent was concentrated under reduced pressure to obtain (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-5, 700 mg, yield: 82.8%).

[0427] 1 HNMR(400MHz, DMSO-d6)δ11.42(s,1H),7.68(dd,J=32.9,7.1Hz,2H),7.44–7.22(m,10H),6.91(d,J=8.7Hz ,4H),5.92(d,J=4.8Hz,1H),5.56(d,J=5.7Hz,1H),5.40(d,J=8.0Hz,1H),5.16(t,J=5.2Hz,1H),4.36(q,J= 5.6Hz,1H),3.99(d,J=3.4Hz,1H),3.87(s,2H),3.76(s,6H),3.57(t,J=1.5Hz,4H),3.45(t,J=6.0Hz,2H), 3.33–3.15(m,4H),3.09(q,J=6.7Hz,2H),1.40(d,J=7.0Hz,2H),1.24(d,J=3.8Hz,38H),0.90–0.84(m,3H).

[0428] Step 6: Synthesis of (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphono)oxy)-2-(2-(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound N6U)

[0429] Pretreatment: (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-5, 300 mg, 0.288 mmol, 1 eq) was dissolved in anhydrous pyridine (10 mL), concentrated under reduced pressure to remove trace amounts of water, repeated twice, and then pumped dry for 30 minutes.

[0430] Anhydrous magnesium sulfate (1.2 g) was added to a three-necked flask. At room temperature, pretreated (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 6-5) was dissolved in anhydrous dichloromethane (12 mL) and then added to the three-necked flask. With stirring, a solution of N,N-diisopropylethylamine (297 mg, 2.3 mmol, 8 eq) and N-methylimidazole (12 mg, 0.143 mmol, 0.5 eq) in dichloromethane (3 mL) was added. The mixture was cooled to 0 °C and stirred for 5 min. Then, a solution of N,N-diisopropylphosphonamide (2-cyanoethyl) ester (545 mg, 2.3 mmol, 8 eq) in dichloromethane (3 mL) was slowly added dropwise. After the addition was complete, the mixture was heated to 25 °C and stirred for 1 h. The reaction of the starting materials was monitored by TLC until it was complete. The reaction solution was filtered, and the filter cake was washed with dichloromethane (10 mL). At 0 °C, the reaction solution was slowly added dropwise to a saturated sodium bicarbonate aqueous solution (30 mL) to separate the organic phase. The aqueous phase was extracted with dichloromethane (10 mL). The organic phases were combined and washed successively with a saturated sodium bicarbonate aqueous solution (20 mL) and a saturated sodium chloride solution (20 mL). The mixture was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. Normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 3% B), followed by concentration of the eluent under reduced pressure, yielded (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphono)oxy)-2-(2-(2-(2-(2-(eicosylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound N6U, 205 mg, yield: 57%).

[0431] MS:m / z 1242.73 [M+H] + .

[0432] 1H NMR (400MHz, DMSO-d6) δ11.46(s,1H),7.73(dd,J=8.2,2.6Hz,1H),7.61(d,J=6.4Hz,1H),7.51(q,J=6.8,6.2Hz,1H),7.41(dd,J=7.6,2.7Hz,2H ),7.36–7.23(m,7H),6.90(ddd,J=8.9,4.2,1.6Hz,4H),5.93(dd,J=11.0,5.3Hz,1H),5.45(d,J=8.5Hz,1H),5.39–5.30(m,1H),4.58(dd,J=11.0 ,5.5Hz,1H),4.16(d,J=15.8Hz,1H),3.86(d,J=1.9Hz,2H),3.83–3.77( m,1H),3.76(d,J=1.6Hz,6H),3.66–3.36(m,9H),3.34–3.05(m,6H),2.77 (t,J=5.8Hz,1H),2.60(td,J=5.8,2.5Hz,1H),1.41(s,2H),1.24(d,J=3 .2Hz,38H),1.15–1.06(m,9H),0.97(d,J=6.8Hz,3H),0.90–0.84(m,3H).

[0433] 31 PNMR(162MHz,DMSO-d6)δ149.28,149.00.

[0434] Example 7

[0435] Step 1: Synthesis of 2,5-dioxopyrrolidone-1-yl docosanoate (compound 7-2)

[0436] Under ice bath conditions, docosanoic acid (compound 7-1, 3.4 g, 10 mmol, 1.0 eq) was dissolved in anhydrous dichloromethane (40 mL), and N-hydroxysuccinimide (1.73 g, 15 mmol, 1.5 eq) was added. After purging with nitrogen, N,N'-diisopropylcarbodiimide (1.89 g, 15 mmol, 1.5 eq) was added dropwise. The reaction was brought to room temperature and stirred continuously for 5 hours. TLC showed that a small amount of starting material remained. The reaction solution was concentrated and dried to obtain a crude product, which was subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 10% B). The eluent was concentrated under reduced pressure to obtain 2,5-dioxopyrrolidine-1-yl docosanoate (compound 7-2, 2.88 g, yield: 66%).

[0437] 1H NMR (400MHz, CDCl3) δ3.00–2.77(m,4H),2.64(t,J=7.5Hz,2H),1.78(p,J=7.5Hz,2H),1.29(s,36H),0.92(t,J=6.6Hz,3H).

[0438] Step 2: Synthesis of N-(2-(2-(2-aminoethoxy)ethoxy)ethyl)cosamide (compound 7-3)

[0439] The starting material 2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-1-amine) (5.07 g, 34.3 mmol, 10 eq) was dissolved in dichloromethane (10 mL). After purging with nitrogen, the reaction was cooled to 0 °C, and a dichloromethane (20 mL) solution of 2,5-dioxopyrrolidine-1-yl docosinate (compound 7-2, 1.5 g, 3.43 mmol, 1.0 eq) was slowly added dropwise. After the addition was complete, the reaction was raised to 20 °C and stirred for 1 hour. TLC showed that the reaction was complete. The reaction solution was poured into water (20 mL), extracted with dichloromethane (50 mL), and the organic phase was washed with saturated sodium chloride aqueous solution (20 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain N-(2-(2-(2-aminoethoxy)ethoxy)ethyl)docosamide (compound 7-3, 1.5 g, yield: 95%).

[0440] 1 H NMR (400MHz, CDCl3) δ6.19(d,J=6.4Hz,1H),3.63(s,4H),3.55(dt,J=9.9,5.1Hz,4H),3.46(q,J=5.2Hz,2H),2.89( t,J=5.2Hz,2H),2.22–2.13(m,2H),1.73(s,2H),1.61(q,J=7.3Hz,2H),1.25(d,J=1.8Hz,36H),0.90–0.86(m,3H).

[0441] Step 3: Synthesis of (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compound 7-4)

[0442] At room temperature, N-(2-(2-(2-(2-aminoethoxy)ethoxy)ethyl)cosamide (compound 7-3, 1.45 g, 3.08 mmol, 1.2 eq) was added to a solution of (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl 1H-imidazol-1-carboxylic acid ester (compound 6-1, 1.49 g, 2.57 mmol, 1.0 eq) in N,N-dimethylformamide (15 mL). After purging with nitrogen, the reaction solution was heated to 80 °C and stirred for 18 hours. TLC showed the reaction was complete. The reaction solution was poured into water (20 mL), extracted with ethyl acetate (50 mL), and the organic phase was collected. The crude product was concentrated under reduced pressure and subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compound 7-4, 1.96 g, yield: 78%).

[0443] 1 H NMR (400MHz, DMSO-d6) δ11.43(s,1H),7.81(t,J=5.5Hz,1H),7.71(d,J=8.1Hz,1H),7.43(t,J=5.7Hz,1H ),5.67(d,J=2.0Hz,1H),5.62(d,J=8.0Hz,1H),5.38–5.31(m,1H),4.58–4.48(m,1H),4.09(dd,J=12.8,4 .3Hz,1H),4.01–3.91(m,1H),3.91–3.82(m,1H),3.51(d,J=9.8Hz,4H),3.44–3.38(m,4H),3.26–3.13(m ,4H),2.05(t,J=7.4Hz,2H),1.48(t,J=7.2Hz,2H),1.26–1.23(m,36H),1.13–0.96(m,28H),0.87(t,3H).

[0444] Step 4: Synthesis of (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compounds 7-5)

[0445] Under ice bath conditions, tetrabutylammonium fluoride (4.83 mL, 4.83 mmol, 2.5 eq) was added dropwise to a tetrahydrofuran (20 mL) solution of (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiazon-9-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compound 7-4, 1.9 g, 1.93 mmol, 1.0 eq) containing 1.9 g, 1.93 mmol, 1.0 eq). After the addition was complete, the temperature was slowly raised to 25 °C and stirred for 1 hour. TLC showed that the reaction was complete. The reaction solution was concentrated under reduced pressure to obtain the crude product, which was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to obtain (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compound 7-5, 1.29 g, yield: 90%).

[0446] 1 H NMR (400MHz, DMSO-d6) δ11.36(s,1H),7.93(d,J=8.2Hz,1H),7.82(t,J=5.7Hz,1H),7.33(t,J=5.7Hz,1H) ,5.99(d,J=6.1Hz,1H),5.69(d,J=8.1Hz,1H),5.50(d,J=5.3Hz,1H),5.21(t,J=4.9Hz,1H),5.04(t,J=5.7 Hz,1H),4.22(p,J=4.4Hz,1H),3.90(q,J=3.3Hz,1H),3.72–3.54(m,2H),3.50(s,4H),3.40(td,J=6.0,4.1 Hz,4H),3.25–3.08(m,4H),2.06(t,J=7.4Hz,2H),1.49(q,J=7.2Hz,2H),1.25(s,36H),0.91–0.83(m,3H).

[0447] Step 5: Synthesis of (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-eicosanomethoxyethoxy)ethoxy)ethyl)carbamate (compounds 7-6)

[0448] Under ice bath conditions, 4,4'-dimethoxytriphenylchloromethane (687 mg, 2.02 mmol, 1.5 eq) was added to a dry pyridine (10 mL) solution of (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compound 7-5, 1 g, 1.35 mmol, 1.0 eq), and nitrogen was purged three times. The reaction was slowly heated to 25 °C and stirred for 16 hours. TLC showed that the reaction was essentially complete. The reaction solution was then cooled to 0 °C and quenched by slow dropwise addition of methanol (0.5 mL). The reaction solution was then concentrated to obtain a crude product, which was subjected to normal-phase column chromatography (silica gel, mobile phase A: ethyl acetate / petroleum ether (1 / 1), mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to obtain (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compound 7-6, 1.2 g, yield: 85%).

[0449] MS: m / z 1065.61 [M+Na] + .

[0450] 1H NMR (400MHz, DMSO-d6) δ11.42(s,1H),7.82(t,J=5.7Hz,1H),7.72(d,J=8.1Hz,1H),7.45–7.22(m,10H ),6.97–6.87(m,4H),5.92(d,J=4.8Hz,1H),5.56(d,J=5.7Hz,1H),5.40(d,J=8.0Hz,1H),5.16(t,J=5. 2Hz,1H),4.36(q,J=5.6Hz,1H),3.99(q,J=4.5Hz,1H),3.76(s,6H),3.51(s,4H),3.46–3.37(m,4H),3 .33–3.12(m,6H),2.06(t,J=7.4Hz,2H),1.47(t,J=7.2Hz,2H),1.32–1.19(m,36H),0.94–0.80(m,3H).

[0451] Step 6: Synthesis of (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphoryl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl(2-(2-(2-eicosanomethoxyethoxy)ethoxy)ethyl)carbamate (compound N7U)

[0452] Pretreatment: (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compound 7-6, 300 mg, 0.288 mmol, 1.0 eq) was azeotropically dried with toluene (2 mL * 2) to remove residual moisture.

[0453] 1H-tetrazole (41.4 mg, 0.576 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (1.2 mL) under nitrogen protection at 25 °C. Then, bis(diisopropylamino)(2-cyanoethoxy)phosphine (178.8 mg, 0.576 mmol, 2.0 eq) was added under nitrogen protection, and the mixture was stirred at 30 °C for 1 hour. A 2 mL solution of pretreated (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compounds 7-6) and N,N-diisopropylethylamine (74.4 mg, 0.576 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 1 hour. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to give (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphoryl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl(2-(2-(2-eicosamidoethoxy)ethoxy)ethyl)carbamate (compound N7U, 302 mg, yield: 84%).

[0454] MS:m / z 1243.74[M+H] + .

[0455] 1H NMR (400MHz, DMSO-d6) δ11.43(s,1H),7.78(t,J=5.6Hz,1H),7.71(dd,J=8.2,3.0Hz,1H),7.46(t,J=5.3Hz,1H),7.39(dd,J=7.7,2.6Hz,2H),7.28(d dd,J=24.5,8.2,4.4Hz,7H),6.92–6.84(m,4H),5.91(dd,J=11.8,5.2Hz,1 H),5.43(d,J=8.1Hz,1H),5.32(dt,J=12.5,5.5Hz,1H),4.56(dt,J=11.4,5 .3Hz,1H),4.13(d,J=15.5Hz,1H),3.78(t,J=6.3Hz,1H),3.73(d,J=1.5Hz ,6H),3.64–3.33(m,12H),3.30–3.04(m,5H),2.75(t,J=5.9Hz,1H),2.58( td,J=5.8,2.4Hz,1H),2.03(t,J=7.4Hz,2H),1.45(t,J=7.1Hz,2H),1.25– 1.20(m,36H),1.13–1.05(m,9H),0.95(d,J=6.7Hz,3H),0.88–0.82(m,3H).

[0456] 31 PNMR(162MHz,DMSO-d6)δ149.28,148.97.

[0457] Example 8

[0458] Step 1: Synthesis of 1-(2-(2-(2-azidoethoxy)ethoxy)ethoxy)docosahexadecane (compound 8-1)

[0459] At room temperature, potassium hydroxide (192 mg, 3.42 mmol, 1.2 eq), tetrabutylammonium bromide (46 mg, 0.143 mmol, 0.05 eq), and 2-(2-(2-azidoethoxy)ethoxy)-1-ethanol (0.5 g, 2.85 mmol, 1 eq) were added sequentially to a solution of 1-bromodocoane (compound 1-1, 1.33 g, 3.42 mmol, 1.2 eq) in 1,4-dioxane (5.7 mL). The reaction mixture was heated to 60 °C and stirred for 2 hours. TLC showed that the reaction was complete. The reaction mixture was cooled to room temperature, water (30 mL) was added, and the mixture was extracted with dichloromethane (30 mL * 2). The organic phases were combined, washed sequentially with saturated sodium chloride aqueous solution, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. Normal-phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: dichloromethane, elution gradient: 0% B to 50% B), followed by concentration of the eluent under reduced pressure, yielded 1-(2-(2-(2-azidoethoxy)ethoxy)ethoxy)docosahexadecane (compound 8-1, 610 mg, yield: 44%).

[0460] 1 H NMR (400MHz, CDCl3) δ3.77–3.66(m,8H),3.65–3.59(m,2H),3.49(t,J=6.8Hz,2H),3 .43(t,J=5.1Hz,2H),1.64–1.59(m,2H),1.39–1.23(m,38H),0.92(t,J=6.7Hz,3H).

[0461] Step 2: Synthesis of 2-(2-(2-(eicosethoxy)ethoxy)ethane-1-amine (compound 8-2)

[0462] 1-(2-(2-(2-azidoethoxy)ethoxy)ethoxy)docosahexadecane (compound 8-1, 1 g, 2.07 mmol, 1 eq) was dissolved in anhydrous tetrahydrofuran (20 mL), then Pd / C (160 mg) was added, and hydrogen was purged three times. The mixture was stirred at 30 °C for 1 hour. The reaction was monitored by TLC until complete. The reaction solution was filtered (with diatomaceous earth as a filter aid), and the filtrate was concentrated under reduced pressure to obtain 2-(2-(2-(docosahexadecyloxy)ethoxy)ethoxy)ethane-1-amine (compound 8-2, 1.1 g, crude product), which was directly used for the next reaction.

[0463] 1 H NMR (400MHz, CDCl3) δ3.64–3.34(m,14H),1.54–1.46(m,2H),1.29–1.11(m,38H),0.81(t,J=6.7Hz,3H).

[0464] Step 3: Synthesis of (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl(2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound 8-3)

[0465] At room temperature, 2-(2-(2-(2-(eicosyl-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl 1H-imidazol-1-carboxylic acid ester (compound 6-1, 470 mg, 0.809 mmol, 1 eq) of N,N-dimethylformamide (12 mL) was added to a solution of (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl 1H-imidazol-1-carboxylic acid ester (compound 6-1, 470 mg, 0.809 mmol, 1 eq). After purging with nitrogen, the reaction solution was heated to 80 °C and stirred for 18 hours. TLC showed that the reaction was complete. The reaction solution was concentrated under reduced pressure to obtain the crude product, which was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: ethyl acetate, elution gradient: 0% B to 40% B). The eluent was concentrated under reduced pressure to give (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl(2-(2-(2-(eicosethoxy)ethoxy)ethyl)carbamate) (compound 8-3,430 g, yield: 55%).

[0466] 1 H NMR (400MHz, DMSO-d6) δ11.44(s,1H),7.73–7.67(m,1H),7.38(t,J=5.8Hz,1H),5.68(s, 1H),5.61(d,J=8.0Hz,1H),5.34(d,J=5.6Hz,1H),4.57–4.48(m,1H),4.12–4.07(m,1H),3 .99–3.91(m,1H),3.89–3.82(m,1H),3.53–3.40(m,10H),3.35–3.30(m,2H),3.19–3.08( m,2H),1.51–1.43(m,2H),1.28–1.22(m,38H),1.09–0.97(m,28H),0.86(t,J=6.7Hz,3H).

[0467] Step 4: Synthesis of (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(2-(eicosylalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound 8-4)

[0468] Under ice bath conditions, tetrabutylammonium fluoride (2.83 mL, 2.83 mmol, 2.5 eq, 1 M in THF) was added dropwise to a tetrahydrofuran (20 mL) solution of (6aR,8R,9R,9aR)-8-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisiloxane-9-yl(2-(2-(2-(eicosethoxy)ethoxy)ethyl)carbamate (compound 8-3, 1.1 g, 1.13 mmol, 1.0 eq) containing 1.13 g, 1.0 eq). After the addition was complete, the temperature was slowly raised to 25 °C and stirred for 0.5 hours. TLC showed the reaction was complete. The reaction solution was concentrated under reduced pressure to obtain the crude product, which was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to obtain (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(2-(eicosylalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound 8-4, 640 g, yield: 77.6%).

[0469] 1 H NMR (400MHz, DMSO-d6) δ11.36(s,1H),7.93(d,J=8.1Hz,1H),7.32(t,J=5.7Hz,1H),5.9 9(d,J=6.1Hz,1H),5.71–5.66(m,1H),5.49(d,J=5.3Hz,1H),5.21(t,J=4.9Hz,1H),5.03 (t,J=5.7Hz,1H),4.25–4.18(m,1H),3.93–3.86(m,1H),3.70–3.55(m,2H),3.53–3.36(m ,12H),3.18–3.08(m,2H),1.53–1.44(m,2H),1.29–1.23(m,38H),0.87(t,J=6.8Hz,3H).

[0470] Step 5: Synthesis of (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound 8-5)

[0471] Under ice bath conditions, 4,4'-dimethoxytriphenylchloromethane (769 mg, 2.27 mmol, 1.5 eq) was added to a dry pyridine (10 mL) solution of (2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl(2-(2-(eicosethoxy)ethoxy)ethyl)carbamate (compound 8-4, 1.1 g, 1.5 mmol, 1.0 eq) and nitrogen was purged three times. The reaction was slowly heated to 25 °C and stirred for 5 hours. TLC showed that the reaction was essentially complete. The reaction solution was then cooled to 0 °C and quenched by slow dropwise addition of 0.5 mL of methanol. The reaction solution was then concentrated to obtain a crude product, which was subjected to normal-phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 75% B). The eluent was concentrated under reduced pressure to obtain (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(eicosylalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound 8-5, 1.4 g, yield: 90%).

[0472] MS: m / z 1030.64 [M+H] + .

[0473] 1 H NMR(400MHz,DMSO-d6)δ11.41(s,1H),7.72(d,J=8.1Hz,1H),7.44–7.24(m,10H),6.95–6 .86(m,4H),5.92(d,J=4.8Hz,1H),5.54(d,J=5.7Hz,1H),5.40(d,J=8.0Hz,1H),5.16(t, J=5.2Hz,1H),4.35(q,J=5.5Hz,1H),3.99(q,J=4.4Hz,1H),3.76(s,6H),3.54–3.36(m,1 2H),3.31–3.09(m,4H),1.48(t,J=6.7Hz,2H),1.25(d,J=2.1Hz,38H),0.89–0.84(m,3H).

[0474] Step 6: Synthesis of (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphoryl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl(2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound N8U)

[0475] Pretreatment: (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(eicosylalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound 8-5, 300 mg, 0.29 mmol, 1 eq) was dissolved in anhydrous pyridine (10 mL), concentrated under reduced pressure to remove trace amounts of water, and repeated three times.

[0476] Pretreated (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(eicosylalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound 8-5) was dissolved in dichloromethane (18 mL), anhydrous magnesium sulfate (2.4 g) was added, and the mixture was purged with nitrogen. A solution of N,N-diisopropylethylamine (301 mg, 2.33 mmol, 8 eq) and N-methylimidazole (12 mg, 0.15 mmol, 0.5 eq) in dichloromethane (0.5 mL) was added under ice bath conditions. After stirring for 5 min, a solution of N,N-diisopropylphosphonamide (2-cyanoethyl) ester (551 mg, 8 eq, 2.33 mmol) in dichloromethane (1 mL) was slowly added dropwise. After the addition was complete, the temperature was raised to 20 °C and stirred for 2 h. TLC showed the reaction was complete. The reaction mixture was filtered, and the filter cake was washed with dichloromethane (20 mL). The filtrate was poured into an ice-cold saturated sodium bicarbonate aqueous solution (40 mL), and the organic phase was separated. The aqueous phase was extracted with dichloromethane (20 mL * 2). The organic phases were combined and then washed with a saturated sodium bicarbonate aqueous solution (30 mL) and a saturated sodium chloride solution (30 mL). After drying with anhydrous magnesium sulfate, the mixture was filtered, and the filtrate was concentrated under reduced pressure and subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0). The eluent was concentrated under reduced pressure to give (2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphoryl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl(2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)ethyl)carbamate (compound N8U, 256 mg, yield: 71%).

[0477] MS:m / z 1230.75[M+H] + .

[0478] 1H NMR (400MHz, DMSO-d6) δ11.43(s,1H),7.72–7.69(m,1H),7.44–7.29(m,4H),7.28–7.23(m,5H),6.90–6.86(m,4H),5.93–5. 89(m,1H),5.44–5.42(m,1H),5.35–5.29(m,1H),4.58–4.52(m,1H),4.17–4.10(m,1H),3.80–3.75(m,1H),3.73(d,J=1.6Hz ,6H),3.64–3.52(m,1H),3.50–3.48(m,8H),3.46–3.33(m,7H),3.29–3.22(m,2H),3.16–3.09(m,2H),2.75(t,J=5.9Hz,1H) ,2.60–2.57(m,1H),1.49–1.42(m,2H),1.23–1.22(m,38H),1.12–1.06(m,8H),0.95(d,J=6.7Hz,4H),0.85(t,J=6.8Hz,3H).

[0479] 31 P NMR(162MHz,DMSO-d6)δ149.35,148.91.

[0480] Example 9

[0481] Step 1: Synthesis of 2-Azideacetic acid (compound 9-2)

[0482] Add ethyl 2-azidoacetic acid (1.0 g, 7.74 mmol, 1.0 eq) to a solution of LiOH (464 mg, 19.4 mmol, 2.5 eq) in H₂O (5 mL), purge with nitrogen, and react at 21 °C for 2 hours. Monitor the reaction by TLC until completion. Adjust the pH to 1-2 with 1N HCl, extract with ethyl acetate (20 mL * 5), combine the organic phases, dry to anhydrous magnesium sulfate, filter, and concentrate the filtrate under reduced pressure to obtain 2-azidoacetic acid (compound 9-2, 568 mg, crude product), which was directly used in the next reaction.

[0483] 1 H NMR (400MHz, DMSO-d6) δ13.13(s,1H),3.98(s,2H).

[0484] Step 2: Synthesis of 2,5-dioxopyrrolidone-1-yl-2-azidoacetate (compound 9-3)

[0485] Under nitrogen protection, a solution of N-hydroxysuccinimide (645 mg, 5.60 mmol, 1.0 eq) in N,N-dimethylformamide (6 mL) was added dropwise to a solution of 2-azidoacetic acid (compound 9-2, 568 mg, 5.60 mmol, 1.0 eq) and N,N'-dicyclohexylcarbodiimide (1.16 g, 5.60 mmol, 1.0 eq) in N,N-dimethylformamide (10 mL). After the addition was complete, the reaction was carried out at 21 °C for 2 days. After 4 hours, the reaction was monitored by TLC until it was complete. The reaction solution was filtered, and the filter cake was washed with ethyl acetate (30 mL). The filtrate was collected and washed with water (20 mL*3), saturated NaHCO3 aqueous solution (20 mL*2), and saturated NaCl aqueous solution (20 mL*3), respectively. The filtrate was dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain 2,5-dioxopyrrolidine-1-yl-2-azidoacetate (compound 9-3, 1.0 g, crude product), which was directly used in the next step of the reaction.

[0486] Step 3: Synthesis of (2R,3R,3aS,9aR)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-hydroxy-2,3,3a,9a-tetrahydro-6H-furano[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one (compound 9-4)

[0487] At 0 °C, 2,2'-dehydro-uridine (compounds 1-3, 5.00 g, 22.1 mmol, 1.0 eq) was dissolved in anhydrous pyridine (50 mL). 4,4'-bismethoxytriphenylmethyl chloride (4.12 g, 12.2 mmol, 0.55 eq) was added in portions, and the temperature was restored to 21 °C, and the reaction was continued for 1 hour. After 1 hour, the reaction temperature was lowered to 0 °C, and 4,4'-bismethoxytriphenylmethyl chloride (4.12 g, 12.2 mmol, 0.55 eq) was added in portions to the reaction solution. The temperature was then restored to 21 °C, and the reaction was continued for 1 hour. The reaction was monitored by TLC until it was complete. Water (50 mL) was added to the reaction solution, and the mixture was extracted with dichloromethane (20 mL * 3). The combined organic phases were washed sequentially with saturated sodium chloride aqueous solution (20 mL * 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 15% B). The eluent was concentrated under reduced pressure to obtain (2R,3R,3aS,9aR)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-hydroxy-2,3,3a,9a-tetrahydro-6H-furano[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one (compound 9-4, 9.1 g, yield: 78%).

[0488] 1H NMR(400MHz,DMSO-d6)δ7.95(d,J=7.4Hz,1H),7.35–7.19(m,5H),7.17–7.12(m,4H) ,6.87–6.81(m,4H),6.33(d,J=5.6Hz,1H),5.96(d,J=4.5Hz,1H),5.88(d,J=7.4Hz,1 H),5.21(dd,J=5.7,1.2Hz,1H),4.36–4.27(m,1H),4.22(ddd,J=7.3,4.4,2.8Hz,1H ), 3.73(d,J=1.6Hz,6H), 2.95(dd,J=10.3,4.4Hz,1H), 2.82(dd,J=10.3,7.3Hz,1H).

[0489] Step 4: Synthesis of 1-((3aR,4R,6R,6aS)-6-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(trichloromethyl)-3a,4,6,6a-tetrahydrofurano[3,4-d]oxazol-4-yl)pyrimidine-2,4(1H,3H)-dione (compounds 9-5)

[0490] At 21°C under nitrogen protection, NaH (189.2 mg, 4.73 mmol, 0.5 eq, 60% in mineral oil) was added to trichloroacetonitrile (25 mL). After stirring the reaction solution for 5 minutes, compound (2R,3R,3aS,9aR)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-hydroxy-2,3,3a,9a-tetrahydro-6H-furano[2',3':4,5]oxazolo[3,2-a]pyrimidin-6-one (compound 9-4, 5.0 g, 9.46 mmol, 1.0 eq) was added. The reaction was then heated to 90°C and continued for 16 hours. The reaction was monitored by TLC until it was complete. The reaction solution was concentrated under reduced pressure to obtain a crude product, which was then subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 50% B). The eluent was concentrated under reduced pressure to give 1-((3aR,4R,6R,6aS)-6-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(trichloromethyl)-3a,4,6,6a-tetrahydrofurano[3,4-d]oxazol-4-yl)pyrimidine-2,4(1H,3H)-dione (compound 9-5, 4.6 g, yield: 72%).

[0491] 1H NMR (400MHz, DMSO-d6) δ11.42(d,J=2.2Hz,1H),7.83(d,J=8.0Hz,1H),7.42–7.27( m,4H),7.26–7.16(m,5H),6.86(dd,J=10.7,8.0Hz,4H),5.91(d,J=2.2Hz,1H),5.7 0–5.59(m,1H),5.50–5.41(m,1H),5.32–5.22(m,1H),4.14(dt,J=8.0,4.1Hz,1H), 3.73(d,J=3.1Hz,6H), 3.48(dd,J=10.2,7.8Hz,1H), 3.18(dd,J=10.2,3.9Hz,1H).

[0492] Step 5: Synthesis of 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compounds 9-6)

[0493] Under nitrogen protection at 21°C, 1-((3aR,4R,6R,6aS)-6-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(trichloromethyl)-3a,4,6,6a-tetrahydrofurano[3,4-d]oxazol-4-yl)pyrimidine-2,4(1H,3H)-dione (compound 9-5, 4.6 g, 6.84 mmol, 1.0 eq) was dissolved in anhydrous ethanol (18 mL), and then 6N NaOH aqueous solution (9 mL) was added. The reaction solution was heated to 70°C and the reaction was continued for 16 hours. The reaction was monitored by TLC until complete. The reaction solution was concentrated under reduced pressure, and saturated ammonium chloride aqueous solution (30 mL) was added. The solution was extracted with dichloromethane (40 mL * 3). The organic phases were combined and washed successively with water (20 mL) and saturated sodium chloride aqueous solution (20 mL * 2). After drying with anhydrous magnesium sulfate, the solution was filtered and concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 50% B). The eluent was concentrated under reduced pressure to obtain 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 9-6, 2.62 g, yield: 72%).

[0494] 1H NMR (400MHz, DMSO-d6) δ7.62(d,J=8.1Hz,1H),7.50–7.29(m,4H),7.28–7.18(m,5H),6.99–6.79(m,4H),5.66(d,J=7.1Hz,1 H),5.39(d,J=8.1Hz,1H),3.97(dq,J=7.2,3.3Hz,2H),3.74(s,6H),3.47–3.27(m,2H),3.20(ddd,J=28.4,10.4,3.9Hz,2H).

[0495] Step 6: Synthesis of 2-azido-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)acetamide (compounds 9-7)

[0496] Under nitrogen protection and in an ice bath, a tetrahydrofuran (2 mL) solution of 2,5-dioxopyrrolidone-1-yl-2-azidoacetate (2 mL) was added dropwise to a tetrahydrofuran (5 mL) solution of 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 9-6, 500 mg, 0.92 mmol, 1.0 eq) and N,N-diisopropylethylamine (296.1 mg, 2.29 mmol, 2.5 eq). After the addition was complete, the temperature was raised to 21 °C and the reaction was allowed to proceed for 16 hours. The reaction was monitored by TLC until complete. Water (20 mL) was added to the reaction mixture, followed by extraction with dichloromethane (20 mL x 3). The organic phase was washed with saturated NaCl (10 mL x 2). The aqueous and saturated NaCl phases were combined, and the mixture was extracted again with ethyl acetate (10 mL x 2). The combined dichloromethane and ethyl acetate organic phases were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 4% B). The eluent was concentrated under reduced pressure to obtain 2-azido-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)acetamide (compound 9-7, 502 mg, yield: 87%).

[0497] 1H NMR (400MHz, DMSO-d6) δ11.36(s,1H),8.25(d,J=8.5Hz,1H),7.65(d,J=8.1Hz,1H),7.37(dd, J=27.1,7.4Hz,4H),7.27(d,J=8.4Hz,5H),6.91(d,J=8.6Hz,4H),5.90(d,J=8.0Hz,1H),5.84 (d,J=4.7Hz,1H),5.43(d,J=8.0Hz,1H),4.67(td,J=8.2,5.7Hz,1H),4.23–4.15(m,1H),4.03 (d,J=3.7Hz,1H),3.91(s,2H),3.74(s,6H),3.32–3.26(m,1H),3.18(dd,J=10.6,3.2Hz,1H).

[0498] Step 7: Synthesis of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(4-dococosyl-1H-1,2,3-triazol-1-yl)acetamide (compounds 9-8)

[0499] 2-Azide-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)acetamide (compound 9-7, 1.3 g, 2.07 mmol, 1.0 eq) and tetracosyl-1-yne (compound 1-2, 1.04 g, 3.1 mmol, 1.5 eq) were dissolved in 13 mL of a mixed solution of tetrahydrofuran / tert-butanol / water (3:1:1). Under nitrogen protection, CuSO4 (99 mg, 0.62 mmol, 0.3 eq) and sodium vitamin C (614.6 mg, 3.1 mmol, 1.5 eq) were added sequentially to the reaction solution, and the reaction was carried out at 21 °C under nitrogen protection for 16 h. The reaction was monitored by TLC until complete. Water (10 mL) and saturated NaHCO3 aqueous solution (20 mL) were added to the reaction mixture. Extraction was performed with ethyl acetate (30 mL x 3). The organic phases were combined, washed with water (20 mL x 2), dried over anhydrous sodium sulfate, and filtered through diatomaceous earth. The filter cake was washed with dichloromethane (50 mL) and ethyl acetate (50 mL), respectively. The mixture was concentrated under reduced pressure to obtain the crude product, which was then subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methyl methacrylate). Alcohol, elution gradient: 0% B), the eluent was concentrated under reduced pressure to give N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(4-dococosyl-1H-1,2,3-triazol-1-yl)acetamide (compound 9-8, 1.7 g, yield: 85.3%).

[0500] MS:m / z 964.61[M+H] + .

[0501] 1H NMR (400MHz, DMSO-d6) δ11.37(d,J=2.0Hz,1H),8.52(d,J=8.4Hz,1H),7.75(s,1H),7.64(d,J=8.1Hz,1H),7.35(dd,J=30.8,7.4H z,4H),7.25(d,J=8.7Hz,5H),6.89(d,J=8.6Hz,4H),5.94(d,J=8.0Hz,1H),5.89(d,J=4.7Hz,1H),5.39(dd,J=8.1,2.0Hz,1H),5.2 1–5.05(m,2H),4.65(td,J=8.2,5.7Hz,1H),4.19(td,J=5.3,2.2Hz,1H),4.05(d,J=2.9Hz,1H),3.73(s,6H),3.29(dd,J=10.6,4.4 Hz,1H),3.19(dd,J=10.6,3.2Hz,1H),2.60(t,J=7.6Hz,2H),1.56(q,J=7.0Hz,2H),1.22(d,J=1.8Hz,38H),0.84(t,J=6.8Hz,3H).

[0502] Step 8: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(4-dococosyl-1H-1,2,3-triazol-1-yl)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N9U)

[0503] Pretreatment: N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(4-docodialkyl-1H-1,2,3-triazol-1-yl)acetamide (compound 9-8, 300 mg, 0.3 mmol, 1 eq) was dissolved in anhydrous pyridine (10 mL) and concentrated under reduced pressure to remove trace amounts of water.

[0504] Pretreated N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(4-dococosyl-1H-1,2,3-triazol-1-yl)acetamide (compound 9-8) was dissolved in dichloromethane (18 mL), anhydrous magnesium sulfate (2.4 g) was added, and the mixture was purged with nitrogen. The mixture was cooled to an ice bath, and then a solution of N,N-diisopropylethylamine (322 mg, 2.4 mmol, 8 eq) and N-methylimidazole (12 mg, 0.15 mol, 0.5 eq) in dichloromethane (0.5 mL) was added. After stirring for 5 minutes, a solution of N,N-diisopropylphosphonamide (2-cyanoethyl) ester (591 mg, 2.4 mmol, 8 eq) in dichloromethane (1 mL) was slowly added dropwise. After the addition was complete, the mixture was heated to 23 °C and stirred for 2 hours. TLC showed that the reaction proceeds were completely reacted. The reaction solution was filtered through diatomaceous earth, and the filter cake was washed with dichloromethane (20 mL). The filtrate was poured into an ice-cold saturated sodium bicarbonate aqueous solution (40 mL), and the organic phase was separated. The aqueous phase was extracted with dichloromethane (10 mL * 3). The organic phases were combined and then washed with a saturated sodium bicarbonate aqueous solution (20 mL) and a saturated sodium chloride solution (20 mL). The solution was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The filtrate was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methane). Alcohol, elution gradient: 0% B to 5% B), the eluent was concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(4-dococosyl-1H-1,2,3-triazol-1-yl)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N9U, 220 mg, yield: 60.8%).

[0505] MS:m / z 1163.70[M+H] + .

[0506] 1H NMR (400MHz, DMSO-d6) δ11.47(s,1H),8.72(dd,J=15.0,8.4Hz,1H),7.74(d,J=3.8Hz,1H),7.67(d,J=8.0Hz,1H),7.40–7.27(m,4H),7.26–7.2 0(m,5H),6.88–6.86(m,4H),6.01(d,J=8.0Hz,1H),5.43(dd,J=8.2,2.6 Hz,1H),5.19–5.12(m,1H),5.07–5.02(m,1H),4.89–4.73(m,1H),4.48– 4.31(m,1H),4.29–4.15(m,1H),3.92–3.76(m,2H),3.73(s,6H),3.60–3 .45(m,2H),3.29–3.18(m,2H),2.79–2.76(m,1H),2.69–2.66(m,1H),2. 62–2.57(m,2H),1.61–1.56(m,2H),1.23–1.22(m,38H),1.14–1.11(m,6 H), 1.05 (d, J = 6.6Hz, 3H), 0.95 (d, J = 6.6Hz, 3H), 0.85 (d, J = 6.4Hz, 3H).

[0507] 31 P NMR(162MHz,DMSO-d6)δ149.54,147.05.

[0508] Example 10

[0509] Step 1: Synthesis of 2-(2-(dococosylamino)-2-oxoethoxy)acetic acid (compound 10-2)

[0510] Under nitrogen protection at 0°C, 1-aminodocoane (compound 10⁻¹, 200 mg, 0.61 mmol, 1.0 eq) was dissolved in tetrahydrofuran (3 mL), followed by the addition of diethylene glycol anhydride (74.9 mg, 0.65 mmol, 1.05 eq). The temperature was then raised to 21°C and the reaction was continued for 4 hours. The reaction was monitored by TLC until complete. The reaction solution was concentrated under reduced pressure to obtain 2-(2-(docodecylamino)-2-oxoethoxy)acetic acid (compound 10⁻², 277 mg, crude product), which was directly used in the next step.

[0511] 1H NMR (400MHz, DMSO-d6) δ12.66(s,1H),7.81(s,1H),4.08(d,J=9.0Hz,2H),3.93(s,2H ),3.08(q,J=6.6Hz,2H),1.41(d,J=8.9Hz,2H),1.23(s,38H),0.85(t,J=6.6Hz,3H).

[0512] Step 2: Synthesis of 2-(2-(2,5-dioxopyrrolidone-1-yl)-2-oxoethoxy)-N-eicosylacetamide (compound 10-3)

[0513] Under nitrogen protection at 21°C, compound 2-(2-(dococosylamino)-2-oxoethoxy)acetic acid (compound 10-2, 500 mg, crude) was dissolved in anhydrous tetrahydrofuran (6 mL), followed by the addition of anhydrous acetonitrile (4 mL) solutions of N,N-diisopropylethylamine (175.6 mg, 1.36 mmol, 1.2 eq) and 2-succinimide-1,1,3,3-tetramethylurea tetrafluoroborate (408.9 mg, 1.36 mmol, 1.2 eq), and the reaction was continued for 3 hours. The reaction was monitored by TLC until complete. The reaction solution was concentrated under reduced pressure. The residue was dissolved in dichloromethane (20 mL), and extracted with 0.1 N ice-cold HCl aqueous solution (10 mL). The aqueous phase was extracted with dichloromethane (20 mL * 3). The organic phases were combined and washed successively with water (10 mL) and saturated sodium chloride aqueous solution (10 mL * 2). After drying with anhydrous sodium sulfate, the solution was concentrated under reduced pressure to obtain 2-(2-(2,5-dioxopyrrolidone-1-yl)-2-oxoethoxy)-N-cosicoalkylacetamide (compound 10-3, 698.2 mg, crude product), which was directly used in the next step.

[0514] Step 3: Synthesis of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-dococosylamino)-2-oxoethoxy)acetamide (compound 10-4)

[0515] At 0 °C, 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 9-6, 600 mg, 1.13 mmol, 1.0 eq) and N,N-diisopropylethylamine (292.6 mg, 2.26 mmol, 2.0 eq) were dissolved in anhydrous tetrahydrofuran (7 mL). A solution (10 mL) of anhydrous tetrahydrofuran of 2-(2-(2,5-dioxopyrrolidone-1-yl)-2-oxoethoxy)-N-docosahexadecylacetamide (compound 10-3, 698.2 mg, crude) was added dropwise to the reaction mixture. The temperature was raised to 21 °C and the reaction was continued for 16 hours. The reaction was monitored by TLC until complete, and the crude product was obtained by concentration under reduced pressure. Normal-phase column chromatography (silica gel, mobile phase A: ethyl acetate, mobile phase B: dichloromethane, elution gradient: 0% B to 1% B), followed by concentration of the eluent under reduced pressure, yielded N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-docosahexamethylamino)-2-oxoethoxy)acetamide (compound 10-4, 652 mg, two-step yield: 59.5%).

[0516] 1 H NMR (400MHz, DMSO-d6) δ11.34(s,1H),7.97(t,J=5.8Hz,1H),7.89(d,J=8.5Hz,1H),7.67(d,J=8.1Hz,1H),7.36(dd, J=29.2,7.4Hz,4H,7.28–7.25(m,5H),6.91–6.88(m,4H),5.92(d,J=7.8Hz,1H),5.83(d,J=4.9Hz,1H),5.42(d,J=8. 1Hz,1H),4.65(q,J=7.8Hz,1H),4.19(q,J=4.5,2.5Hz,1H),4.04(q,J=3.6Hz,1H),4.01(s,2H),3.94(s,2H),3.74(s ,6H), 3.31–3.17(m,2H),3.08(q,J=6.7Hz,2H),1.39(d,J=6.9Hz,2H),1.22(d,J=3.0Hz,38H), 0.86(d,J=6.5Hz,3H).

[0517] Step 4: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(2-docosahexamethylamino)-2-oxoethoxy)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N10U)

[0518] Pretreatment: N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-docosahexamethylamino)-2-oxoethoxy)acetamide (compound 10-4, 300 mg, 1 eq, 0.3 mmol) was dissolved in anhydrous pyridine (10 mL), concentrated under reduced pressure to remove trace amounts of water, and repeated three times.

[0519] Pretreated N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-docosylamino)-2-oxoethoxy)acetamide (compound 10-4) was dissolved in dichloromethane (18 mL), anhydrous magnesium sulfate (2.4 g) was added, nitrogen was purged, and the mixture was added under ice bath conditions. A solution of N,N-diisopropylethylamine (324 mg, 2.472 mmol, 8 eq) and N-methylimidazole (12 mg, 0.156 mmol, 0.5 eq) in dichloromethane (0.5 mL) was stirred for 10 minutes. Then, a solution of N,N-diisopropylphosphonamide (2-cyanoethyl) ester (588 mg, 2.472 mmol, 8 eq) in dichloromethane (0.5 mL) was slowly added dropwise. After the addition was complete, the temperature was raised to 20 °C and stirred for 2 hours. TLC showed the reaction was complete. The reaction solution was directly filtered to remove anhydrous magnesium sulfate. The filter cake was washed with dichloromethane (5 mL), extracted with saturated sodium bicarbonate solution (20 mL), and washed with saturated sodium chloride solution (10 mL). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(2-docosahexamethylamino)-2-oxoethoxy)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N10U, 216 mg, yield: 62%).

[0520] MS:m / z 1169.69[M+H] + .

[0521] 1 H NMR(400MHz, DMSO-d6)δ11.40(s,1H),8.13–7.93(m,2H),7.69(d,J=8.2Hz,1H),7.41–7.29(m,4H),7.27–7.23(m, 5H),6.90–6.86(m,4H),5.97(t,J=7.2Hz,1H),5.48–5.45(m,1H),4.89–4.76(m,1H),4.48–4.18(m,2H),4.08–3.92 (m,4H),3.83–3.75(m,1H),3.73(d,J=1.6Hz,6H),3.71–3.63(m,1H),3.55–3.44(m,2H),3.29–3.21(m,2H),3.11– 3.05(m,2H),2.74–2.62(m,2H),1.43–1.36(m,2H),1.22–1.21(m,38H),1.12–0.95(m,12H),0.84(t,J=6.8Hz,3H).

[0522] 31 P NMR(162MHz,DMSO-d6)δ149.23,147.90.

[0523] Example 11

[0524] Step 1: Synthesis of 2-[2-[2-(eicosylalkoxy)ethoxy]ethoxy]ethanol (compound 11-1)

[0525] Under nitrogen protection at 21°C, KOH (559.2 mg, 8.47 mmol, 1.1 eq) was added to a solution of 1,4-dioxane (48 mL) of 2,2'-(ethane-1,2-diylbis(oxy))bis(ethanol) (4.16 g, 27.7 mmol, 3.6 eq). The mixture was heated to 60°C and reacted for 1 hour until the KOH was completely dissolved. The temperature was then lowered to 25–30°C, and 1-bromodocoane (compound 1-1, 3.0 g, 7.70 mmol, 1.0 eq) and tetrabutylammonium bromide (124.2 mg, 0.39 mmol, 0.05 eq) were added sequentially to the reaction solution. The mixture was then reacted at 110°C under nitrogen protection for 1 hour. The reaction was monitored by TLC until it was complete. Water (20 mL) was added to the reaction solution, and the mixture was extracted with dichloromethane (30 mL*3). The organic phase was then washed with water (30 mL*3) and saturated NaCl solution (20 mL*2), respectively. After drying with anhydrous sodium sulfate, the mixture was filtered. The filtrate was concentrated under reduced pressure to obtain the crude product, which was then subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 18% B to 25% B). The eluent was concentrated under reduced pressure to obtain 2-[2-[2-(eicosylalkoxy)ethoxy]ethoxy]ethanol (compound 11-1, 2.62 g, yield: 74%).

[0526] 1 H NMR (400MHz, CDCl3) δ3.74–3.56(m,12H),3.45(t,J=6.8Hz,2H),1.59(q,J=7.0Hz,2H),1.25(s,38H),0.88(t,J=6.7Hz,3H).

[0527] Step 2: Synthesis of 2-(2-(2-(eicosyloxy)ethoxy)ethoxy)acetic acid (compound 11-1)

[0528] 2-[2-[2-(eicosethoxy)ethoxy]ethanol (compound 11-1, 1.6 g, 3.49 mmol, 1.0 eq) was dissolved in a mixture of dichloromethane (30 mL) and 15% NaHCO3 aqueous solution (10 mL). KBr (83.0 mg, 0.70 mmol, 0.2 eq) and 2,2,6,6-tetramethylpiperidine oxide (11.0 mg, 0.07 mmol, 0.02 eq) were added sequentially. The mixture was stirred at 21 °C for 5 minutes, then cooled to 0 °C. Trichloroisocyanuric acid (1.62 g, 6.98 mmol, 2.0 eq) was slowly added in portions to the reaction solution. After the addition was complete, the temperature was raised to 21 °C and the reaction was carried out for 16 hours. The reaction was monitored by TLC until it was complete. Isopropanol (3 mL) was slowly added dropwise to quench the reaction. After stirring at 21 °C for 5 min, formic acid (2 mL) was slowly added dropwise to separate the organic phase. The remaining small amount of aqueous phase was extracted again with dichloromethane (10 mL * 5). The organic phases were combined, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane (0.03% formic acid), mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to obtain 2-(2-(2-(eicosylalkoxy)ethoxy)ethoxy)acetic acid (compound 11-2, 1.34 g, yield: 81%).

[0529] 1 HNMR (400MHz, CDCl3) δ4.16 (s, 2H), 3.79-3.74 (m, 2H), 3.70 (td, J = 5.3, 4.3, 2.2Hz, 4H), 3.60 (dd, J =5.8,3.6Hz,2H),3.45(t,J=6.8Hz,2H),1.58(q,J=6.9Hz,2H),1.25(s,38H),0.88(t,J=6.7Hz,3H).

[0530] Step 3: Synthesis of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)acetamide (compound 11-3)

[0531] Under nitrogen protection at 21°C, 2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)acetic acid (compound 11-2, 563 mg, 1.19 mmol, 1.3 eq) was dissolved in dichloromethane (7 mL), followed by the addition of N,N-diisopropylethylamine (356 mg, 2.75 mmol, 3.0 eq). After the reaction solution was completely dissolved, the temperature was lowered to 0°C, and then 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (229 mg, 1.19 mmol, 1.3 eq) was added sequentially. The mixture was reacted with 1-hydroxybenzotriazole (161 mg, 1.19 mmol, 1.3 eq), slowly restored to 21 °C, and reacted under nitrogen protection for 50 minutes. Then, 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 9-6, 500 mg, 0.92 mmol, 1.0 eq) was added, and the mixture was reacted under nitrogen protection at 21 °C for 16 hours. The reaction was monitored by TLC until completion. Saturated NaHCO3 solution (30 mL) and dichloromethane (30 mL x 3) were added to the reaction solution for extraction. The organic phase was then washed sequentially with water (20 mL x 2) and saturated NaCl solution (20 mL x 2), and the organic phase was separated. The solution was dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to...). 5% B), the eluent was concentrated under reduced pressure to give N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)acetamide (compound 11-3, 1.41 g, yield: 76.9%).

[0532] MS:m / z 1000.62[M+H] + .

[0533] 1H NMR (400MHz, DMSO-d6) δ11.32(s,1H),7.66(d,J=8.1Hz,1H),7.53(d,J=8.4Hz,1H),7.42–7.29(m,4H),7.26(d,J=8.6Hz,5H), 6.89(d,J=8.4Hz,4H),5.94(d,J=5.1Hz,1H),5.89(d,J=7.8Hz,1H),5.44(d,J=8.1Hz,1H),4.61(q,J=7.7Hz,1H),4.17(q,J=6. 0,4.4Hz,1H),4.04(q,J=3.5Hz,1H),4.00–3.87(m,2H),3.57(ddd,J=14.0,8.5,4.6Hz,6H),3.51–3.46(m,2H),3.36(t,J=6.6 Hz,2H),3.31–3.26(m,1H),3.19(dd,J=10.6,3.2Hz,1H),1.46(t,J=6.8Hz,2H),1.22(d,J=4.2Hz,38H),0.85(t,J=6.5Hz,3H).

[0534] Step 4: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)acetamyl)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N11U)

[0535] Pretreatment: The substrate N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)acetamide (compound 11-3, 300 mg, 0.3 mmol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0536] Under nitrogen protection, 1H-tetrazole (42.9 mg, 0.6 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (1.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (186.4 mg, 0.6 mmol, 2.0 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A 2 mL solution of pretreated N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-(2-(2-(eicosylalkoxy)ethoxy)ethoxy)acetamide (compound 11-3) and N,N-diisopropylethylamine (77.5 mg, 0.6 mmol, 2.0 eq)) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol / acetone (1 / 1), elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)acetamyl)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N11U, 260 mg, yield: 72%).

[0537] MS:m / z 1200.74 [M+H] + .

[0538] 1H NMR (400MHz, DMSO-d6) δ11.38(s,1H),7.68(d,J=8.1Hz,1H),7.53(dd,J=56 .7,8.6Hz,1H),7.43–7.28(m,4H),7.25(td,J=9.7,9.2,3.0Hz,5H),6.88(dd ,J=8.7,4.6Hz,4H),5.92(dd,J=7.7,3.1Hz,1H),5.49(dd,J=8.1,5.2Hz,1H) ,4.81(dq,J=23.0,7.7Hz,1H),4.22(dt,J=46.6,4.4Hz,1H),4.05–3.78(m,2 H),3.73(d,J=1.6Hz,6H),3.57(dddt,J=29.3,23.7,12.6,6.7Hz,12H),3.3 5(td,J=6.5,1.8Hz,2H),3.32–3.21(m,2H),2.75(t,J=5.9Hz,1H),2.64(td, J=5.9,2.7Hz,1H),1.46(t,J=6.6Hz,2H),1.22(d,J=3.6Hz,38H),1.14–1.10 (m,6H),1.07(d,J=6.7Hz,3H),0.98(d,J=6.7Hz,3H),0.84(t,J=6.6Hz,3H).

[0539] 31 P NMR(162MHz,DMSO-d6)δ149.62,148.10.

[0540] Example 12

[0541] Step 1: Synthesis of docosanehydrazine (compound 12-2)

[0542] Methyl docosanoate (compound 12-1, 5.0 g, 14.1 mmol, 1.0 eq) was dissolved in ethanol (50 mL), and then hydrazine hydrate (3.53 g, 70.5 mmol, 5.0 eq) was added. The reaction mixture was heated to 80 °C and stirred under reflux for 6 hours. TLC showed that the reaction was essentially complete. The reaction mixture was cooled to 22 °C, and the precipitated white solid was collected by filtration. Petroleum ether (20 mL) was added to the collected white solid, and the mixture was slurried to remove the remaining small amount of raw material. The mixture was filtered again, and the solid was collected and dried under vacuum to give docosanoyl hydrazine (compound 12-2, 2.75 g, yield: 55%).

[0543] 1HNMR (400MHz, CDCl3) δ2.26–2.09(m,2H),1.71–1.63(m,2H),1.35–1.20(m,38H),0.92(t,J=6.7Hz,3H).

[0544] Step 2: Synthesis of (E)-4-(2-docosahydrazideylidene)valeric acid (compound 12-3)

[0545] Under nitrogen protection, docosanoyl hydrazide (compound 12-2, 3.1 g, 8.74 mmol, 1.0 eq) was dissolved in dichloromethane (60 mL). Acetic acid (1.25 g, 20.89 mmol, 2.39 eq) and 4-oxopentanoic acid (1.0 g, 8.74 mmol, 1.0 eq) were added sequentially at 21 °C, and the mixture was then heated to 38 °C and reacted for 1.5 h. TLC showed that the reaction was essentially complete. The reaction solution was concentrated under reduced pressure to obtain a crude product. Petroleum ether (30 mL) was added and the mixture was stirred. The solid was collected and dried under vacuum to obtain (E)-4-(2-docosanoyl hydrazideylidene)pentanoic acid (compound 12-3, 2.96 g, yield: 95%).

[0546] 1 HNMR(400MHz,DMSO-d6)δ12.02(s,1H),9.94(d,1H),2.51–2.40(m,6H),1.84 (d,J=7.9Hz,3H),1.51(d,J=7.5Hz,2H),1.26(s,36H),0.87(t,J=6.6Hz,3H).

[0547] Step 3: Synthesis of (E)-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-(2-docosahexahydrazide)pentanamide (compound 12-4)

[0548] To a solution of (E)-4-(2-eicosanoylhydrazide)valerate (compound 12-3, 970 mg, 2.14 mmol, 1.3 eq) in anhydrous dichloromethane (20 mL), 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound) was added sequentially. The following substances were added: 9-6,900 mg (1.65 mmol, 1.0 eq), 1-ethyl-(3-dimethylaminopropyl)carbodiimide (474 ​​mg, 2.48 mmol, 1.5 eq), 1-hydroxybenzotriazole (335 mg, 2.48 mmol, 1.5 eq), and N,N-diisopropylethylamine (639 mg, 4.95 mmol, 3.0 eq). The mixture was stirred at 21 °C for 16 hours. TLC showed the reaction was nearly complete. The reaction mixture was poured into water (20 mL), extracted with dichloromethane (20 mL), washed with saturated sodium chloride aqueous solution (20 mL), dried over anhydrous magnesium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. Normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 3% B) was performed, and the eluent was concentrated under reduced pressure to give (E)-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-(2-docosahexahydrazide)pentanamide (compound 12-4, 1.1 g, yield: 68%).

[0549] MS:m / z 980.61[M+H] + .

[0550] 1HNMR (400MHz, DMSO-d6) δ11.33(s,1H),9.93(d,J=11.1Hz,1H),7.96(dd,J=40.6,8.5Hz,1H),7.65(dd,J=8.2,1. 8Hz,1H),7.46–7.19(m,9H),6.91(d,J=8.4Hz,4H),5.89(dd,J=8.0,3.3Hz,1H),5.70(dd,J=13.6,4.7Hz,1H),5.4 1(d,J=8.0Hz,1H),4.64(q,J=7.9Hz,1H),4.17(q,J=4.8Hz,1H),4.04(q,J=3.5Hz,1H),3.76(s,6H),3.31–3.13(m ,2H),2.51–2.33(m,6H),1.83(d,J=7.6Hz,3H),1.53(d,J=8.1Hz,2H),1.24(d,J=3.5Hz,36H),0.91–0.81(m,3H).

[0551] Step 4: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-((E)-4-(2-eicosodehydrazideylidene)pentanylamino)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N12U)

[0552] Pretreatment: The substrate (E)-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-(2-eicosanoylhydrazide)pentanamide (compound 12-4, 300 mg, 0.3 mmol, 1.0 eq) was azeotropically dehydrated with toluene (4.0 ml * 2).

[0553] Under nitrogen protection, 1H-tetrazole (43.75 mg, 0.6 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (1.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (190.19 mg, 0.6 mmol, 2.0 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A 2 mL solution of pretreated (E)-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-(2-eicosanoylhydrazide)pentanamide (compound 12-4) and N,N-diisopropylethylamine (79.11 mg, 0.6 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane / petroleum ether (1 / 1, 0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-((E)-4-(2-eicosodehydrazideylidene)pentanylamino)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N12U, 160 mg, yield: 44%).

[0554] MS:m / z 1180.72[M+H] + .

[0555] 1 H NMR (400MHz, DMSO-d6) δ11.43(s,1H),10.28–9.86(m,1H),8.40–8.04(m,1H),7.73–7.63(m,1H),7.47–7. 22(m,9H),6.94–6.87(m,4H),6.04–5.89(m,1H),5.45(d,J=8.1Hz,1H),5.00–4.74(m,1H),4.52–4.15(m,2 H),3.76(d,J=1.5Hz,10H),3.27(d,J=26.0Hz,2H),2.84–2.64(m,2H),2.50–2.08(m,6H),1.90–1.78(m,3 H),1.52(s,2H),1.25(d,J=2.6Hz,36H),1.17–1.05(m,10H),0.98(t,J=7.5Hz,2H),0.87(t,J=6.6Hz,3H).

[0556] Example 13

[0557] Step 1: Synthesis of (E)-4-((dococoyloxy)imino)valerate (compound 13-1)

[0558] O-dodecylhydroxylamine (compound 4-2, 1.0 g, 2.93 mmol, 1.0 eq) was dissolved in dichloromethane (20 mL) under nitrogen protection at 21 °C. Then, acetic acid (420 mg, 7.0 mmol, 2.39 eq) and 4-oxopentanoic acid (323 mg, 2.78 mmol, 1.0 eq) were added sequentially. The reaction was carried out in a water bath at 38 °C for 1.5 h under nitrogen protection. The reaction was monitored by TLC until complete. The reaction solution was concentrated under reduced pressure to obtain a crude product as a white solid. Petroleum ether (15 mL) was added to the crude product, and the mixture was stirred in a water bath at 50 °C for 5 min. After standing at 21 °C for 10 min, a solid precipitated out. The solid was filtered, and the filter cake was washed with petroleum ether (30 mL). The filter cake was collected and dried under vacuum to obtain (E)-4-((docodecoxy)imino)pentanoic acid (compound 13-1, 1.15 g, yield: 88%).

[0559] 1 H NMR(400MHz, CDCl3)δ4.05(dt,J=13.4,6.7Hz,2H),2.68–2.51(m,4H),1.92( d,J=35.5Hz,3H),1.63(q,J=6.9Hz,2H),1.25(s,38H),0.88(t,J=6.8Hz,3H).

[0560] Step 2: Synthesis of (E)-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-((eicosicoalkoxy)imino)pentanamide (compound 13-2)

[0561] Under nitrogen protection at 21°C, (E)-4-((dococooxy)imino)valerate (compound 13-1 1.05 g, 2.38 mmol, 1.3 eq) was dissolved in dichloromethane (16 mL), followed by the addition of N,N-diisopropylethylamine (712 mg, 5.5 mmol, 3.0 eq). After the reaction solution was completely dissolved, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (458 mg, 2.38 mmol, 1.3 eq) and 1-hydroxybenzotriazole (322 mg, 2.38 mmol, 1.3 eq) were added sequentially at 0°C, and the reaction was then carried out under nitrogen protection at 21°C for 50 minutes. 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 9-6, 1 g, 1.84 mmol, 1.0 eq) was added, and the reaction was continued for 16 hours under nitrogen protection at 21 °C. The reaction was monitored by TLC until complete. Water (20 mL) was added to the reaction mixture, followed by extraction with dichloromethane (20 mL * 3). The organic phase was washed sequentially with saturated NaHCO3 aqueous solution (20 mL * 2) and saturated NaCl aqueous solution (20 mL * 2). The mixture was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to obtain (E)-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-((dococoyloxy)imino)pentanamide (compound 13-2, 1.3 g, yield: 75.3%).

[0562] MS:m / z 967.61[M+H] + .

[0563] 1H NMR (400MHz, DMSO-d6) δ11.32(d,J=2.3Hz,1H),7.95(d,J=8.4Hz,1H),7.63(dd,J=8.2,3.9Hz,1H),7.43–7.30(m,4H),7.25(td,J=6. 5,6.1,3.1Hz,5H),6.91–6.88(m,4H),5.88(dd,J=8.1,2.8Hz,1H),5.70(dd,J=15.1,4.7Hz,1H),5.39(dd,J=8.1,2.1Hz,1H),4.64(t d,J=8.3,5.8Hz,1H),4.15(dt,J=7.2,3.8Hz,1H),4.01(q,J=3.4Hz,1H),3.88(t,J=6.6Hz,2H),3.74(s,6H),3.26(dd,J=10.6,4.4Hz ,1H),3.18(dd,J=10.5,3.4Hz,1H),2.43–2.30(m,4H),1.72(d,J=1.4Hz,3H),1.54(q,J=6.9Hz,2H),1.23(s,38H),0.86–0.82(m,3H).

[0564] Step 3: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-((E)-4-((eicosicoalkoxy)imino)pentamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N13U)

[0565] Pretreatment: The substrate (E)-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-((dococoyloxy)imino)pentanamide (compound 13-2, 300 mg, 0.31 mmol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0566] Under nitrogen protection, 1H-tetrazole (40 mg, 0.56 mmol, 1.8 eq) was dissolved in anhydrous dichloromethane (1.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (174 mg, 0.56 mmol, 1.8 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A 2 mL solution of pretreated (E)-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-((eicosicoalkoxy)imino)pentanamide (compound 13-2) and N,N-diisopropylethylamine (80.2 mg, 0.62 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol / acetone (1 / 1), elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-((E)-4-((eicosicoalkoxy)imino)pentamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N13U, 262 mg, yield: 72%).

[0567] MS:m / z 1167.73 [M+H] + .

[0568] 1H NMR (400MHz, DMSO-d6) δ11.41(d,J=3.1Hz,1H),8.14(dt,J=15.8,8.3Hz,1H),7.65(dd,J=8.1,2.0Hz,1H),7.49–7.15(m,9H) ,6.88(dd,J=9.0,2.8Hz,4H),5.94(t,J=7.0Hz,1H),5.41(d,J=8.1Hz,1H),4.83(dq,J=30.2,7.9Hz,1H),4.48–4.26(m,1H), 4.19(d,J=33.1Hz,1H),4.02–3.85(m,2H),3.83(s,6H),3.73–3.42(m,4H),3.31–3.17(m,2H),2.70(dt,J=39.7,6.0Hz,2H), 2.45–2.22(m,4H),1.73(dd,J=8.8,5.2Hz,3H),1.58–1.47(m,2H),1.22(s,39H),1.13–0.95(m,12H),0.84(t,J=6.6Hz,3H).

[0569] 31 P NMR(162MHz,DMSO-d6)δ148.99,147.54.

[0570] Example 14

[0571] Step 1: Synthesis of octadecane-1-yne (compound 14-2)

[0572] Under nitrogen protection at 21°C, lithium ethylenediamine complex (3.05 g, 29.8 mmol, 3.25 eq) was dissolved in dimethyl sulfoxide (10 mL), and 1-bromohexadecane (15-1, 2.8 g, 9.17 mmol, 1.0 eq) was added. The reaction was carried out at 21°C under nitrogen protection for 2.5 h, and then the temperature was increased to 66°C and the reaction was carried out for 0.5 h. The reaction was monitored by TLC until complete. The pH of the reaction solution was adjusted to 1 with 1M HCl aqueous solution. Saturated sodium chloride aqueous solution (10 mL) and ethyl acetate (10 mL * 3) were added to the reaction solution for extraction. The organic phase was washed twice with 1M HCl aqueous solution and twice with saturated sodium chloride aqueous solution. After drying with anhydrous sodium sulfate, the mixture was filtered and the residue was obtained by vacuum distillation. The residue was directly subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B). The eluent was concentrated under reduced pressure to give octadecane-1-yne (compound 14-2, 2.3 g, yield: 98%).

[0573] 1H NMR (400MHz, CDCl3) δ2.18(td,J=7.1,2.6Hz,2H),1.93(t,J=2.6Hz,1H),1.52(p,J=7.0Hz,2H),1.44–1.34(m,2H),1.26(s,24H),0.88(t,J=6.8Hz,3H).

[0574] Step 2: Synthesis of 1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(4-hexadecyl-1H-1,2,3-triazol-1-yl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 14-3)

[0575] Under nitrogen protection, 1-((2R,3R,4S,5R)-3-azido-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 1-5, 500 mg, 0.88 mmol), octadecane-1-yne (compound 14-2, 438 mg, 1.75 mmol, 2.0 eq), CuSO4 (41.9 mg, 0.26 mmol, 0.3 eq) and sodium vitamin C (260.0 mg, 1.31 mmol, 1.5 eq) were dissolved in a tetrahydrofuran / tert-butanol / water (3 / 1 / 1, 5 mL) mixture and reacted at 21°C for 5 hours under nitrogen protection. The reaction was monitored by TLC until it was complete. NaHCO3 (10 mL) was added to the reaction solution, and the mixture was extracted with ethyl acetate (20 mL * 3). The combined organic phases were washed successively with saturated sodium chloride aqueous solution (20 mL * 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to obtain 1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(4-hexadecyl-1H-1,2,3-triazol-1-yl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 14-3, 582 mg, yield: 83%).

[0576] 1H NMR(400MHz, DMSO-d6)δ11.41(d,J=2.1Hz,1H),7.89–7.78(m,2H),7.47–7.31(m,4H),7.30–7.12(m,5H ),6.99–6.86(m,4H),6.40(d,J=4.8Hz,1H),5.75(d,J=5.6Hz,1H),5.43(ddd,J=11.5,7.4,3.4Hz,2H), 4.49(q,J=6.3Hz,1H),4.22(td,J=5.6,2.9Hz,1H),3.74(s,6H),3.35(dd,J=10.8,5.4Hz,1H),3.29(dd ,J=10.5,2.8Hz,1H),2.61(t,J=7.6Hz,2H),1.57(q,J=7.3Hz,2H),1.23(s,26H),0.85(t,J=6.6Hz,3H).

[0577] Step 3: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(4-hexadecyl-1H-1,2,3-triazol-1-yl)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N14U)

[0578] Pretreatment: Substrate 1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(4-hexadecyl-1H-1,2,3-triazol-1-yl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 14-3, 380 mg, 0.42 mol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0579] Under nitrogen protection, 1H-tetrazazole (47 mg, 0.66 mmol, 1.8 eq) was dissolved in anhydrous dichloromethane (1.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (204 mg, 0.66 mmol, 1.8 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A dichloromethane solution (3 mL) of pretreated 1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(4-hexadecyl-1H-1,2,3-triazol-1-yl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 14-3) and N,N-diisopropylethylamine (94 mg, 0.73 mmol, 2.0 eq) was added to the reaction mixture. The reaction was continued at 25°C under nitrogen protection for 2 hours. The reaction was monitored by TLC until completion, and then directly subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol / acetone (1 / 1), elution gradient: 0% B to 1% B). The eluent was concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(4-hexadecyl-1H-1,2,3-triazol-1-yl)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N14U, 236 mg, yield: 82%).

[0580] MS: m / z 1022.59 [M+H] + .

[0581] 1 H NMR (400MHz, DMSO-d6) δ11.44(s,1H),7.87(dd,J=21.5,7.3Hz,2H),7.47–7.31(m,4H),7.29–7.20(m,5H),6. 89(ddd,J=8.4,5.2,2.7Hz,4H),6.38(t,J=4.4Hz,1H),5.70–5.49(m,1H),5.49–5.37(m,1H),4.41(d,J=18.7 Hz,1H),3.74(d,J=2.9Hz,6H),3.66–3.33(m,4H),3.16(s,2H),2.79(t,J=5.8Hz,1H),2.59(dt,J=14.9,7.6H z,3H),1.58(d,J=8.3Hz,2H),1.23(s,26H),0.99(d,J=7.7Hz,5H),0.87–0.81(m,7H),0.74(d,J=6.7Hz,3H).

[0582] 31 P NMR(162MHz,DMSO-d6)δ150.04,148.28.

[0583] Example 15

[0584] Step 1: Synthesis of 1-azidohexadecane (compound 15-2)

[0585] Sodium azide (5.32 g, 82 mmol, 5 eq) was added to a solution of 1-bromohexadecane (14-1, 5 g, 16.4 mmol, 1 eq) in N,N-dimethylformamide (50 mL). After purging with nitrogen, the mixture was stirred at 70 °C for 1 h. TLC showed that the reaction proceeds were completely reacted. The reaction solution was poured into ice water (500 mL), extracted with ethyl acetate (100 mL * 3), and the organic phase was washed with water and saturated sodium chloride solution (100 mL * 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to give 1-azidohexadecane (compound 15-2, 4.2 g, yield: 96%).

[0586] 1 H NMR (400MHz, CDCl3) δ3.25(t,J=7.0Hz,2H),1.64–1.55(m,2H),1.38–1.26(m,26H),0.88(t,J=6.6Hz,3H).

[0587] Step 2: Synthesis of 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 15-3)

[0588] Pretreatment: 2-(((2R,3S,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 2-8, 750 mg, 2.21 mmol, 1 eq) was dissolved in anhydrous pyridine (5 mL), concentrated under reduced pressure, and repeated three times.

[0589] Pretreated 2-(((2R,3S,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 2-8) was dissolved in anhydrous pyridine (10 mL), nitrogen was purged, the mixture was cooled to an ice bath, 4,4'-dimethoxytriphenylchloromethane (1.12 g, 3.32 mmol, 1.5 eq) was added, nitrogen was purged again, the mixture was heated to 23 °C, and stirred for 8 h. The reaction was monitored by TLC until complete. The reaction solution was diluted with dichloromethane (20 mL) and poured into ice-cold saturated NaHCO3 solution (60 mL). The solution was extracted with dichloromethane (20 mL x 3 mL), and the organic phase was washed with saturated sodium chloride solution (20 mL). The solution was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 6% B). The eluent was collected and concentrated under reduced pressure to obtain 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 15-3, 930 mg, yield: 66%).

[0590] 1 H NMR (400MHz, DMSO-d6) δ11.40(s,1H),8.35(t,J=5.8Hz,1H),7.72(d,J=8.2Hz,1H ),7.40–7.30(m,4H),7.27–7.23(m,5H),6.91(d,J=8.6Hz,4H),5.82(d,J=2.1Hz,1 H),5.47(d,J=8.0Hz,1H),5.27(dd,J=8.2,1.8Hz,1H),4.26–4.19(m,2H),4.08–4 .02(m,3H),3.94–3.91(m,2H),3.74(s,6H),3.31–3.24(m,2H),3.13–3.12(m,1H).

[0591] Step 3: Synthesis of 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 15-4)

[0592] 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 15-3, 930 mg, 1 eq, 1.45 mmol) and 1-azidohexadecane (compound 15-2) 582 mg (1.5 eq, 2.17 mmol) was dissolved in a mixed solution of tetrahydrofuran (15 mL) and H2O (3 mL). Under ice bath conditions, CuSO4 (116 mg, 0.5 eq, 0.73 mmol) and sodium vitamin C (431 mg, 1.5 eq, 2.17 mmol) were added. After nitrogen purging, the mixture was heated to 28 °C and stirred for 3 h. The reaction was monitored by TLC until complete. The reaction solution was filtered through diatomaceous earth. The filter cake was washed with dichloromethane (40 mL). The filtrate was poured into a saturated sodium bicarbonate solution (40 mL), extracted with dichloromethane (20 mL * 3), and the organic phase was washed with a saturated sodium chloride solution (30 mL). The mixture was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: methanol / ethyl acetate (1 / 1), elution gradient: 0% B to 6% B). The eluent was collected under reduced pressure. After concentration, 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 15-4, 950 mg, yield: 72%) was obtained.

[0593] 1 H NMR (400MHz, DMSO-d6) δ11.41(s,1H),8.44(t,J=6.0Hz,1H),7.91(s,1H),7.72(d,J=8.0Hz,1H),7.39– 7.30(m,4H),7.28–7.22(m,5H),6.90(d,J=8.6Hz,4H),5.81(d,J=2.0Hz,1H),5.47(d,J=7.8Hz,1H),5.2 6(dd,J=8.0,2.0Hz,1H),4.36(t,J=6.4Hz,2H),4.28(t,J=7.2Hz,2H),4.25–4.18(m,2H),4.08–3.99(m ,3H),3.74(s,6H),3.26–3.23(m,2H),1.77(q,J=7.2Hz,2H),1.22–1.21(m,26H),0.84(t,J=6.6Hz,3H).

[0594] Step 4: Synthesis of (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N15U)

[0595] Pretreatment: The substrate 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 15-4, 380 mg, 0.42 mol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0596] Under nitrogen protection, 1H-tetrazole (58.6 mg, 0.84 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (1.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (252 mg, 0.84 mol, 2.0 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A 3 mL solution of pretreated 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)acetamide (compound 14-4) and N,N-diisopropylethylamine (108 mg, 0.84 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 4% B). The eluent was concentrated under reduced pressure to give (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N15U, 393 mg, yield: 85%).

[0597] MS:m / z 1109.66237[M+H] + .

[0598] 1 H NMR (400MHz, DMSO-d6) δ11.40(s,1H),8.11(t,J=6.0Hz,1H),7.86(d,J=8.8Hz,1H),7.75(dd,J=8.2,5.8Hz,1H),7.40–7.29(m, 4H),7.28–7.22(m,5H),6.90–6.86(m,4H),5.87(dd,J=7.6,2.8Hz,1H),5.27(dd,J=8.2,2.0Hz,1H),4.46–4.11(m,9H),3.79–3 .76(m,1H),3.73(d,J=2.2Hz,6H),3.70–3.58(m,1H),3.52–3.43(m,2H),3.39–3.35(m,1H),3.28–3.24(m,1H),2.75–2.71(m,1 H),2.61–2.58(m,1H),1.78–1.71(m,2H),1.22–1.21(m,26H),1.10–1.02(m,9H),0.91(d,J=6.8Hz,3H),0.84(t,J=6.6Hz,3H).

[0599] 31 P NMR(162MHz,DMSO-d6)δ149.59,148.29.

[0600] Example 16

[0601] Step 1: Synthesis of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamide (compound 16-1)

[0602] Under nitrogen protection, 2-azido-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)acetamide (compound 9-7, 300 mg, 0.48 mmol, 1.0 eq), octadecane-1-yne (compound 14-2, 179 mg, 0.72 mmol, 2.0 eq), CuSO4 (23 mg, 0.14 mmol, 0.3 eq) and sodium vitamin C (142 mg, 0.72 mmol, 1.5 eq) were dissolved in a mixed solution of tetrahydrofuran / tert-butanol / water (3 / 1 / 1, 5 mL) and reacted at 21°C for 3 hours under nitrogen protection. The reaction was monitored by TLC until it was complete. NaHCO3 (10 mL) was added to the reaction solution, and the mixture was extracted with ethyl acetate (20 mL * 3). The combined organic phases were washed successively with saturated sodium chloride aqueous solution (20 mL * 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 4% B). The eluent was concentrated under reduced pressure to obtain N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamide (compound 16-1,400 mg, yield: 87%).

[0603] Step 2: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N17U)

[0604] Pretreatment: The substrate N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamide (compound 16-1,380 mg, 0.42 mol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0605] Under nitrogen protection, 1H-tetrazole (25 mg, 0.35 mmol, 1.8 eq) was dissolved in anhydrous dichloromethane (1.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (108 mg, 0.35 mmol, 1.8 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A 1 mL solution of pretreated N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamide (compound 16-1) and N,N-diisopropylethylamine (50 mg, 0.39 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol / acetone (1 / 1), elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N17U, 188 mg, yield: 90%).

[0606] MS:m / z 1079.6188[M+H] + .

[0607] 1H NMR (400MHz, DMSO-d6) δ11.47(s,1H),8.72(dd,J=15.0,8.5Hz,1H),7.76–7.64(m,2H),7.53–7.08(m,10H),6.94–6.81(m ,4H),6.01(d,J=7.9Hz,1H),5.43(d,J=8.1Hz,1H),5.23–5.00(m,2H),4.81(dq,J=40.7,7.8Hz,1H),4.23(d,J=41.1Hz,1H ),3.73(s,8H),3.53(dt,J=22.9,8.6Hz,2H),3.31–3.11(m,2H),2.82–2.75(m,1H),2.68(d,J=6.5Hz,1H),2.60(td,J=7.7 ,2.9Hz,2H),1.57(s,2H),1.23(s,26H),1.12(dd,J=6.8,3.5Hz,6H),1.00(dd,J=40.2,6.7Hz,6H),0.85(t,J=6.6Hz,3H).

[0608] 31 P NMR(162MHz,DMSO-d6)δ149.55,147.07.

[0609] Example 17

[0610] Step 1: Synthesis of 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methoxy)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 17-1)

[0611] 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(prop-2-yn-1-oxy)tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 3-4, 2.0 g, 3.42 mmol, 1.0 eq) was dissolved in tetrahydrofuran (20 mL) and water (4 mL). The reaction mixture was cooled to 0 °C under nitrogen protection. Octadecan-1-yne (compound 15-2, 1.1 g, 4.11 mmol, 1.2 eq) was added to the reaction mixture, followed by copper sulfate (273 mg, 1.73 mmol, 0.5 eq) and sodium vitamin C (1.02 g, 5.13 mmol, 1.5 eq). The mixture was then heated to room temperature (21 °C) and stirred for 2 hours. TLC showed that the reaction was basically complete. The two batches of reaction solution were combined and poured into a saturated NaHCO3 solution (50 mL). The solution was extracted with dichloromethane (50 mL). The organic phase was then washed with a saturated sodium chloride aqueous solution (50 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain a yellow crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 6% B). The eluent was concentrated under reduced pressure to obtain the crude product. The crude product was dissolved in ethyl acetate (30 mL), washed successively with ethylenediaminetetraacetic acid (0.5 M, 20 mL * 2), ultrapure water (20 mL), and saturated sodium chloride aqueous solution (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated to give 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methoxy)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 17-1, 2.1 g, yield: 72%).

[0612] 1 H NMR(400MHz,DMSO-d6)δ11.40(s,1H),8.10(s,1H),7.69(d,J=8.1Hz,1H),7.42– 7.21(m,9H),6.97–6.89(m,4H),5.88(d,J=3.9Hz,1H),5.32–5.21(m,2H),4.75( s,2H),4.37–4.24(m,3H),4.12(t,J=4.6Hz,1H),4.00(q,J=5.3,4.3Hz,1H),3.7 6(s,6H),3.33–3.18(m,2H),1.86–1.72(m,2H),1.30–1.19(m,26H),0.86(t,3H).

[0613] Step 2: Synthesis of (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N16U)

[0614] Pretreatment: Substrate 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methoxy)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 17-1, 300 mg, 0.35 mmol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0615] Under nitrogen protection, 1H-tetrazole (50.3 mg, 0.70 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (1.4 mL). Under nitrogen protection, N,N-diisopropylphosphoramide (2-cyanoethyl) ester (218.8 mg, 0.70 mmol, 2.0 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A 2 mL solution of pretreated 1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methoxy)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 17-1) and N,N-diisopropylethylamine (91.01 mg, 0.70 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol / acetone (1 / 1), elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to give (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-((1-hexadecyl-1H-1,2,3-triazol-4-yl)methoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N16U, 240 mg, yield: 65%).

[0616] MS: m / z 1052.60 [M+H] +

[0617] 1H NMR (400MHz, DMSO-d6) δ11.41(s,1H),8.03(d,J=13.4Hz,1H),7.73(dd,J=16.4,8.1Hz,1H),7.44–7.19(m,9H),6 .97–6.86(m,4H),5.89(t,J=3.7Hz,1H),5.24(dd,J=19.1,8.1Hz,1H),4.74(dd,J=8.0,1.9Hz,2H),4.57–4.39(m ,1H),4.36–4.26(m,3H),4.19–4.07(m,1H),3.85–3.46(m,10H),3.34–3.25(m,2H),2.80–2.73(m,1H),2.67–2.6 0(m,1H),1.84–1.71(m,2H),1.28–1.19(m,26H),1.16–1.04(m,9H),0.96(t,J=6.7Hz,3H),0.87(t,J=6.7Hz,3H).

[0618] 31 P NMR(162MHz,DMSO-d6)δ149.27,148.82.

[0619] Example 18

[0620] Step 1: Synthesis of 2-(hexadecyloxy)isoindoline-1,3-dione (compound 18-1)

[0621] At room temperature, N-hydroxyphthalimide (403 mg, 2.47 mmol, 1.5 eq) and potassium carbonate (341 mg, 2.47 mmol, 1.5 eq) were added sequentially to a solution of 1-bromohexadecane (14-1,500 mg, 1.65 mmol, 1.0 eq) in N,N-dimethylformamide (10 mL). The reaction mixture was heated to 80 °C and stirred for 4 h. TLC showed that the reaction was complete. The reaction mixture was poured into water (20 mL) to form a suspension. The suspension was extracted with petroleum ether / ethyl acetate (10 / 1; 30 mL). The organic phase was collected and washed sequentially with ultrapure water (10 mL), saturated sodium chloride aqueous solution (10 mL), dried over anhydrous magnesium sulfate, filtered, and the residue was concentrated and dried under vacuum to give 2-(hexadecyloxy)isoindoline-1,3-dione (compound 18-1,507 mg, yield: 80%).

[0622] 1H NMR (400MHz, CDCl3) δ7.88–7.80(m,2H),7.77–7.70(m,2H),4.20(t,J=6.8Hz,2H), 1.79(p,J=7.1Hz,2H),1.47(p,J=7.0Hz,2H),1.25(s,24H),0.88(t,J=6.6Hz,3H).

[0623] Step 2: Synthesis of hexadecylhydroxylamine (compound 18-2)

[0624] At room temperature, hydrazine hydrate (1.4 g, 28 mmol, 2.0 eq) was added dropwise to a suspension of 2-(hexadecyloxy)isoindoline-1,3-dione (compound 18-1, 5.4 g, 14 mmol, 1.0 eq) in anhydrous ethanol (100 mL), and stirring was continued at this temperature for 2 h. TLC showed the reaction was complete. The reaction solution was concentrated to give the crude product. The crude product was subjected to normal-phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to give hexadecylhydroxylamine (compound 18-2, 3.44 g, yield: 96%).

[0625] 1 H NMR (400MHz, CDCl3) δ3.69 (t, J = 6.7Hz, 2H), 1.61 (q, J = 6.9Hz, 2H), 1.29 (s, 26H), 0.92 (t, J = 6.7Hz, 3H).

[0626] Step 3: Synthesis of methyl 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)propionate (compound 18-3)

[0627] Pretreatment: Solid methyl 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propionate (compound 5-3, 1.6 g, 4.84 mmol, 1.0 eq) was dissolved in ultradry pyridine (20 mL), concentrated under reduced pressure, and repeated 3 times.

[0628] Under nitrogen protection, a dry pyridine (16 mL) solution of pretreated methyl 3-(((2R,3R,4R,5R)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxy-5-(hydroxymethyl)tetrahydrofuran-3-yl)oxy)propionate (compound 5-3) was cooled to 0 °C, and then 4,4'-dimethoxytriphenylchloromethane (2.46 g, 7.27 mmol, 1.5 eq) was added, and the system was purged with nitrogen three times. The system was slowly heated to 25 °C and stirred for 17 hours. TLC showed that the reaction was complete. The reaction solution was then cooled to 0 °C, and the reaction was quenched by slowly adding 1 mL of methanol. The reaction solution was then concentrated to obtain a crude product, which was subjected to normal-phase column chromatography (silica gel, mobile phase A: petroleum ether / ethyl acetate (1 / 1), mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to obtain methyl 3-(((2R,3R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)propionate (compound 18-3, 2.6 g, yield: 85%).

[0629] 1 H NMR (400MHz, DMSO-d6) δ11.38(s,1H),7.71(d,J=8.0Hz,1H),7.40–7.23(m,9H),6.95–6.87(m,4H),5.78(d,J=3.7Hz,1H),5.30(d,J=8.0Hz,1H),5.1 2(d,J=6.5Hz,1H),4.19(q,J=6.1Hz,1H),4.00–3.90(m,2H),3.86–3.78(m ,2H),3.74(s,6H),3.58(s,3H),3.32–3.18(m,2H),2.61(t,J=6.0Hz,2H).

[0630] Step 4: Synthesis of 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)propionic acid (compound 18-4)

[0631] Under ice bath conditions, 0.1 M NaOH (80 mL) was slowly added to an ultradry pyridine (80 mL) solution of methyl 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)propionate (compound 18-3, 1.6 g, 2.53 mmol, 1.0 eq). The solution was heated to 20 °C and stirred at this temperature for 30 min. TLC showed that the reaction was complete. The reaction solution was poured into a saturated ammonium chloride (80 mL) solution, extracted with ethyl acetate (100 mL), and then washed with a saturated sodium chloride aqueous solution (80 mL). The organic phase was collected and diisopropylethylamine (981 mg, 7.59 mmol, 3.0 eq) was slowly added to it. The mixture was then dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain 3-(((2R,3R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)propionic acid (compound 18-4, crude product), which was used directly in the next step.

[0632] Step 5: Synthesis of 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(hexadecyloxy)propionamide (compound 18-5)

[0633] At room temperature (22°C), hexadecyl hydroxylamine (compound 18-2, 977 mg, 3.8 mmol, 1.5 eq), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (728 mg, 3.8 mmol, 1.5 eq), 1-hydroxybenzotriazole (513 mg, 3.8 mmol, 1.5 eq) and N,N-diisopropylethylamine (981 mg, 7.59 mmol, 3.0 eq) were added sequentially to an anhydrous dichloromethane (30 mL) solution of 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)propionic acid (compound 18-4, crude) at 977 mg, 3.8 mmol, 1.5 eq), N,N-diisopropylethylamine (981 mg, 7.59 mmol, 3.0 eq) at 22°C. The reaction mixture was stirred at this temperature for 16 hours. TLC showed the reaction was complete. The reaction solution was concentrated and dried. The residue was dissolved in ethyl acetate (100 mL) and washed successively with water (50 mL) and saturated sodium chloride aqueous solution (50 mL). The organic phase was collected, dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(hexadecyloxy)propionamide (compound 18-5, 1.43 g, yield: 66%).

[0634] MS:m / z 858.49[M+H] + .

[0635] 1 H NMR (400MHz, DMSO-d6) δ11.38(s,1H),10.88(s,1H),7.70(d,J=8.1Hz,1H),7.42–7.20 (m,9H),6.96–6.85(m,4H),5.77(d,J=3.5Hz,1H),5.28(d,J=8.1Hz,1H),5.15(d,J=6.4 Hz,1H),4.21(q,J=6.0Hz,1H),4.03–3.88(m,2H),3.85–3.65(m,10H),3.32–3.19(m,2H ),2.26(t,J=6.2Hz,2H),1.48(q,J=6.9Hz,2H),1.34–1.17(m,26H),0.92–0.79(m,3H).

[0636] Step 6: Synthesis of (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(3-((hexadecyloxy)amino)-3-oxopropoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N18U)

[0637] Pretreatment: The substrate 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(hexadecyloxy)propionamide (compound 18-5, 300 mg, 0.35 mmol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0638] Under nitrogen protection, 1H-tetrazole (98 mg, 1.4 mmol, 4.0 eq) was dissolved in anhydrous dichloromethane (2.8 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (423 mg, 1.4 mmol, 4.0 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A dichloromethane solution (3 mL) of pretreated 3-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(hexadecyloxy)propionamide (compound 18-5) and N,N-diisopropylethylamine (182 mg, 1.4 mmol, 4.0 eq) was added to the reaction mixture. The reaction was continued at 25°C under nitrogen protection for 2 hours. The reaction was monitored by TLC until completion, and then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give (2R,3R,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(3-((hexadecyloxy)amino)-3-oxopropoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N18U, 240 mg, yield: 65%).

[0639] MS:m / z 1058.60 [M+H] + .

[0640] 1H NMR (400MHz, DMSO-d6) δ11.37(s,1H),10.84(s,1H),7.76(dd,J=15.6,8.1Hz,1H),7.43–7.19(m,9H),6.89(ddd,J=9.4 ,7.1,2.6Hz,4H),5.80(dd,J=6.8,3.4Hz,1H),5.26(dd,J=19.7,8.1Hz,1H),4.46–4.28(m,1H),4.18–4.01(m,2H),3.9 1–3.47(m,14H),3.38–3.33(m,1H),3.30–3.23(m,1H),2.78(t,J=5.8Hz,1H),2.63–2.57(m,1H),2.22(t,J=6.6Hz,2H) ,1.55–1.42(m,2H),1.22(d,J=3.8Hz,26H),1.12(dd,J=11.9,6.7Hz,9H),0.96(d,J=6.7Hz,3H),0.85(t,J=6.6Hz,3H).

[0641] 31 P NMR(162MHz,DMSO-d6)δ149.24,148.70.

[0642] Example 19

[0643] Step 1: Synthesis of 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 19-1)

[0644] Under ice bath conditions, imidazole (509 mg, 7.5 mmol, 3 eq) was added to a solution of 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (15-3, 1.6 g, 2.5 mmol, 1 eq) in N,N-dimethylformamide (16 mL). After stirring for 10 min, tert-butyldimethylchlorosilane (752 mg, 5 mmol, 2 eq) was added. After purging with nitrogen, the mixture was heated to 40 °C and stirred for 14 hours. TLC monitoring showed that the reaction proceeds were complete. The reaction solution was poured into water (100 mL), extracted with ethyl acetate (30 mL * 3), washed with saturated sodium chloride solution (50 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was directly subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to give 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 19-1, 1.6 g, yield: 85%).

[0645] 1 H NMR (400MHz, DMSO-d6) δ11.40(d,J=2.0Hz,1H),7.99(t,J=5.8Hz,1H),7.81(d,J=8.2Hz,1H), 7.40–7.29(m,4H),7.28–7.21(m,5H),6.92–6.86(m,4H),5.85(d,J=2.2Hz,1H),5.32(dd,J=8 .2,2.0Hz,1H),4.34–4.31(m,1H),4.14–3.99(m,4H),3.95–3.82(m,2H),3.74(s,6H),3.39–3 .36(m,1H),3.20–3.16(m,1H),3.08(t,J=2.6Hz,1H),0.73(s,9H),0.02(s,3H),-0.09(s,3H).

[0646] Step 2: Synthesis of 2-(((2R,3R,4R,5R)-2-(4-amino-2-oxopyrimidin-1(2H)-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 19-2)

[0647] To a solution of 2-(((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 19-1, 1.6 g, 2.12 mmol, 1 eq) in acetonitrile (16 mL), 4-dimethylaminopyridine (518 mg, 4.24 mmol, 2 eq) and triethylamine (429 mg, 4.24 mmol, 2 eq) were added, nitrogen was purged, and the solution was cooled to an ice bath. Then, 2,4,6-triisopropylbenzenesulfonyl chloride (962 mg, 3.18 mmol, 1.5 eq) was added. After the addition was complete, nitrogen gas was purged, the temperature was raised to 20°C, and the mixture was stirred for 3 hours. Then, ammonia water (3 mL) was added, and the mixture was stirred at 20°C for another 17 hours. The reaction mixture was monitored by TLC until the reaction was complete. The reaction solution was poured into ice water (100 mL), extracted with EA (50 mL * 2), and the organic phase was washed with saturated sodium chloride solution (50 mL). The solution was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain 2-(((2R,3R,4R,5R)-2-(4-amino-2-oxopyrimidin-1(2H)-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 19-2, 1.6 g, crude product), which was directly used in the next step of the reaction.

[0648] Step 3: Synthesis of N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsilyl)oxy)-3-(2-oxo-2-(prop-2-yn-1-ylamino)ethoxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-3)

[0649] Pretreatment: 2-(((2R,3R,4R,5R)-2-(4-amino-2-oxopyrimidin-1(2H)-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 19-2, 1.6 g, crude)) was dissolved in ultradry pyridine (10 mL), concentrated under reduced pressure, and repeated three times.

[0650] Pretreated 2-(((2R,3R,4R,5R)-2-(4-amino-2-oxopyrimidin-1(2H)-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-3-yl)oxy)-N-(prop-2-yn-1-yl)acetamide (compound 19-2) was dissolved in pyridine (16 mL), purged with nitrogen, and cooled to an ice bath. Benzoyl chloride (358 mg, 2.54 mmol, 1.2 eq) was then added. After the addition was complete, the temperature was raised to 20 °C and stirred for 2 h. The reaction mixture was monitored by TLC until complete. The reaction solution was diluted with dichloromethane (30 mL) and then poured into a saturated sodium bicarbonate solution (100 mL). The organic phase was extracted with methane (50 mL * 3), washed with saturated sodium chloride solution (50 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was directly subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 4% B). The eluent was concentrated under reduced pressure to give N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsilyl)oxy)-3-(2-oxo-2-(prop-2-yn-1-ylamino)ethoxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-3, 1.6 g, yield: 88%).

[0651] 1H NMR (400MHz, DMSO-d6) δ11.34(s,1H),8.50(d,J=7.4Hz,1H),8.01–7.99(m,3H),,7.63(t,J=7.4Hz,1H),7.52(t ,J=7.6Hz,2H),7.42–7.33(m,4H),7.27(dd,J=8.7,1.8Hz,5H),7.18(d,J=7.4Hz,1H),6.92(d,J=8.6Hz,4H),5.9 3(s,1H),4.42–4.39(m,1H),4.33(d,J=15.2Hz,1H),4.25–4.22(m,1H),4.14–4.06(m,2H),4.00–3.84(m,2H),3. 76(s,6H),3.58–3.54(m,1H),3.26–3.23(m,1H),3.08(t,J=2.6Hz,1H),0.70(s,9H),0.01(s,3H),-0.12(s,3H).

[0652] Step 4: Synthesis of N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(2-oxo-2-(prop-2-yn-1-ylamino)ethoxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-4)

[0653] N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsilyl)oxy)-3-(2-oxo-2-(prop-2-yn-1-ylamino)ethoxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-3, 1.6 g, 1.86 mol, 1 eq) was dissolved in tetrahydrofuran (16 mL), and tetrabutylammonium fluoride (1 M in THF, 2.8 mL, 1.5 eq) was added under ice bath conditions. After the addition was complete, the mixture was heated to 20 °C and stirred for 1 h. TLC monitoring showed that the reaction proceeded to completion. The reaction solution was concentrated under reduced pressure and directly subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 4% B). The eluent was concentrated under reduced pressure to give N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(2-oxo-2-(prop-2-yn-1-ylamino)ethoxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-4, 1.2 g, yield: 87%).

[0654] 1 H NMR (400MHz, DMSO-d6) δ11.32 (s, 1H), 8.40–8.35 (m, 2H), 8.00 (d, J = 7.6Hz, 2H), 7.63 (t, J=7.4Hz,1H),7.52(t,J=7.6Hz,2H),7.46–7.33(m,4H),7.29–7.25(m,5H),7.18(d,J=7.4 Hz,1H),6.93(d,J=8.2Hz,4H),5.88(s,1H),5.52(d,J=8.6Hz,1H),4.42–4.30(m,2H),4.2 1–4.13(m,2H),3.76(s,6H),3.96–3.93(m,3H),3.45–3.33(m,2H),3.13(d,J=2.4Hz,1H).

[0655] Step 5: Synthesis of N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(2-(((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-5)

[0656] To a mixture of tetrahydrofuran (10 mL) and H₂O (2 mL) of N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxy-3-(2-oxo-2-(prop-2-yn-1-ylamino)ethoxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-4, 1.2 g, 1.61 mmol, 1 eq) and 1-azidohexadecane (compound 15-2, 646 mg, 2.42 mmol, 1.5 eq), the mixture was cooled to an ice bath. Then anhydrous CuSO₄ (128.6 mg, 0.5 eq, 0.8 mmol) and sodium vitamin C (479 mg, 1.5 eq, 2.42 mmol) were added. After nitrogen purging, the mixture was heated to 30 °C and stirred for 2 h. TLC monitoring showed the reaction proceeded to completion. The reaction solution was diluted with ethyl acetate (30 mL) and poured into a saturated sodium bicarbonate solution (100 mL). Extraction was performed with ethyl acetate (30 mL x 3), followed by extraction with EDTA (0.5 M, pH = 7.4, 50 mL x 10 mL). 4) Wash the organic phase with saturated sodium chloride solution (30 mL), dry with anhydrous sodium sulfate, filter, concentrate the filtrate under reduced pressure, and perform normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). Concentrate the eluent under reduced pressure to give N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(2-(((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-5, 1.4 g, yield: 86%).

[0657] 1H NMR (400MHz, DMSO-d6) δ11.32(s,1H),8.48(t,J=6.0Hz,1H),8.36(d,J=7.4Hz,1H),8.01(d,J=7.8Hz,2H),7.93(s, 1H),7.63(t,J=7.6Hz,1H),7.52(t,J=7.6Hz,2H),7.44–7.35(m,4H),7.31–7.26(m,5H),7.19(d,J=7.4Hz,1H),6.92 (dd,J=8.8,1.8Hz,4H),5.88(s,1H),5.52(d,J=8.6Hz,1H),4.44–4.37(m,3H),4.33–4.27(m,3H),,4.21–4.12(m,2H ),3.99(d,J=4.8Hz,1H),3.76(s,6H),3.44–3.37(m,2H),1.80–1.73(m,2H),1.22–1.21(m,26H),0.86–0.82(m,3H).

[0658] Step 6: Synthesis of (2R,3R,4R,5R)-5-(4-benzamido-2-oxopyrimidin-1(2H)-yl)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(2-(((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N15C)

[0659] Pretreatment: The substrate N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(2-(((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-5, 350 mg, 0.35 mmol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0660] Under nitrogen protection, 1H-tetrazole (49 mg, 0.7 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (1.4 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (209 mg, 0.7 mmol, 2.0 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A 2.5 mL solution of pretreated N-(1-((2R,3R,4R,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(2-(((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 19-5) and N,N-diisopropylethylamine (90 mg, 0.6 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give (2R,3R,4R,5R)-5-(4-benzamido-2-oxopyrimidin-1(2H)-yl)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(2-(((1-hexadecyl-1H-1,2,3-triazol-4-yl)methyl)amino)-2-oxoethoxy)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N15C, 380 mg, yield: 91%).

[0661] MS:m / z 1212.67 [M+H] +

[0662] 1H NMR (400MHz, DMSO-d6) δ11.31(s,1H),8.43–8.37(m,1H),8.16(t,J=6.4Hz,1H),8.01–7.99(m,2H),7.89(d,J=6.4Hz,1H), 7.63(t,J=7.6Hz,1H),7.51(t,J=7.6Hz,2H),7.45–7.32(m,4H),7.31–7.26(m,5H),7.17–7.12(m,1H),6.92–6.89(m,4H),5 .97(d,J=11.6Hz,1H),4.55–4.42(m,1H),4.40–4.16(m,8H),3.75(d,J=2.8Hz,6H),3.68–3.35(m,6H),2.73–2.69(m,1H), 2.61–2.57(m,1H),1.78–1.71(m,2H),1.21–1.19(m,26H),1.11–1.00(m,9H),0.90(d,J=6.8Hz,3H),0.84(t,J=6.6Hz,3H).

[0663] 31 P NMR(162MHz,DMSO-d6)δ150.08,148.16.

[0664] Example 20

[0665] Step 1: Synthesis of (1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione) (Compound 20-1)

[0666] At room temperature, 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidine-2,4(1H,3H)-dione (compound 9-6, 1.0 g, 2.02 mmol, 1.0 eq) was azeotropically dehydrated with toluene (10 mL * 2) and dried with an oil pump for 0.5 h. It was then dissolved in N,N-dimethylformamide (5 mL). Imidazole (412 mg, 6.05 mmol, 3.0 eq) and tert-butyldimethylchlorosilane (456 mg, 3.02 mmol, 1.5 eq) were added sequentially at 0 °C, and the reaction was carried out at 30 °C for 3 h. The reaction was monitored by TLC until complete. Saturated NaHCO3 (20 mL) was added to the reaction solution, and the mixture was extracted with ethyl acetate (30 mL * 3). The combined organic phases were washed successively with saturated sodium chloride aqueous solution (20 mL * 2), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to obtain (1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione) (compound 20-1, 1.2 g, crude product).

[0667] 1 H NMR(400MHz,DMSO-d6)δ11.34(s,1H),7.65(d,J=8.1Hz,1H),7.54–7.30(m,4H) ,7.25(d,J=8.4Hz,5H),6.90(d,J=8.4Hz,4H),5.60(d,J=6.9Hz,1H),5.45(d,J =8.0Hz,1H),4.09(t,J=4.1Hz,1H),3.90(q,J=3.8Hz,1H),3.74(s,6H),3.40(t ,J=6.3Hz,1H),3.23(ddd,J=42.8,10.8,4.0Hz,2H),0.83(s,9H),0.06(s,3H).

[0668] Step 2: Synthesis of (2-azido-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)acetamide) (compound 20-2)

[0669] At 21°C, (1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione) (compound 20-1, 1.2 g, crude) was dissolved in dichloromethane (10 mL), and N,N-diisopropylethylamine (470 mg, 1.82 mmol, 2.0 eq) was added. Then, 2,5-dioxopyrrolidone-1-yl-2-azidoacetate (420 mg, 2.00 mmol, 1.1 eq) was added at 0°C, and the reaction was carried out at 21°C for 5 hours. The reaction was monitored by TLC until completion, and then NaHCO3 was added to the reaction solution. Extracted with dichloromethane (20 mL * 3), the organic phase was washed with saturated NaCl aqueous solution (20 mL * 2), dried over anhydrous sodium sulfate, filtered, and distilled under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give (2-azido-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)acetamide) (compound 20-2, 1.26 g, two-step yield: 83%).

[0670] 1 H NMR (400MHz, DMSO-d6) δ11.43(s,1H),8.30(d,J=8.7Hz,1H),7.71(d,J=8.1Hz,1H ),7.43–7.30(m,4H),7.29–7.23(m,5H),6.90(d,J=8.7Hz,4H),5.88(d,J=6.8Hz,1 H),5.52(dd,J=7.9,1.8Hz,1H),4.64(q,J=7.1Hz,1H),4.35–4.30(m,1H),4.03–3. 78(m,3H),3.74(s,6H),3.23(dd,J=15.3,10.5Hz,2H),0.78(s,9H),-0.08(s,3H).

[0671] Step 3: Synthesis of (N-((2R,3R,4S,5R)-2-(4-amino-2-oxopyrimidin-1(2H)-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-3-yl)-2-azidoacetamide) (compound 20-3)

[0672] Under nitrogen protection at 21°C, 4-dimethylaminopyridine (197 mg, 1.62 mmol, 2 eq) and triethylamine (164 mg, 1.62 mmol, 2 eq) were added to a solution of (2-azido-N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)acetamide) (compound 20-2,600 mg, 0.81 mmol, 1 eq) in acetonitrile (5 mL). After purging with nitrogen, the solution was cooled to 0°C, and then 2,4,6-triisopropylbenzenesulfonyl chloride (367 mg, 1.21 mmol, 1.5 eq) was added. After the addition was complete, the solution was heated to 20°C and stirred for 3 h. The mixture was then monitored by TLC. After the raw materials were completely consumed, ammonia (1.2 mL, 26-28% content) was added, and the mixture was stirred at 21°C for 17 h. The reaction was monitored by TLC until complete. Water (10 mL) was added to the reaction solution, and the mixture was extracted with ethyl acetate (20 mL * 3). After drying with anhydrous sodium sulfate, the mixture was filtered, distilled under reduced pressure, and dried at room temperature with an oil pump to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to obtain (N-((2R,3R,4S,5R)-2-(4-amino-2-oxopyrimidin-1(2H)-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-3-yl)-2-azidoacetamide) (compound 20-3, 1.1 g, three-step yield: 72%).

[0673] Step 4: Synthesis of (N-(1-((2R,3R,4S,5R)-3-(2-azidoacetamido)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide) (compound 20-4)

[0674] At 21°C, (N-((2R,3R,4S,5R)-2-(4-amino-2-oxopyrimidin-1(2H)-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-3-yl)-2-azidoacetamide) (compound 20-3, 1.1 g, 1.48 mmol, 1.0 eq) was added to toluene (10 mL * 2) for azeotropic dehydration, dried under vacuum with an oil pump for 0.5 h, dissolved in anhydrous dichloromethane (5 mL), and N,N-diisopropylethylamine (480 mg, 3.71 mmol, 2.5 eq) was added. Benzoyl chloride (251 mg, 1.78 mmol, 1.2 eq) was added dropwise at 0°C, and the reaction was carried out at 21°C under nitrogen protection for 2 h. The reaction was monitored by LC until complete. At 0°C, saturated NaHCO3 aqueous solution (20 mL) was added dropwise to the reaction mixture. Extraction was performed with dichloromethane (20 mL x 3), dried over anhydrous sodium sulfate, filtered, and then distilled under reduced pressure. The crude product was dried at room temperature using an oil pump. Normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 2% B) was performed. The eluent was concentrated under reduced pressure to give (N-(1-((2R,3R,4S,5R)-3-(2-azidoacetamido)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide) (compound 20-4, 1.1 g, yield: 86%).

[0675] 1 H NMR (400MHz, DMSO-d6) δ11.32(s,1H),8.39(d,J=8.9Hz,1H),8.25(d,J=7.6Hz,1H),8.00( d,J=7.7Hz,2H),7.63(t,J=7.4Hz,1H),7.52(t,J=7.6Hz,2H),7.44–7.21(m,10H),6.91(d, J=8.7Hz,4H),6.01(d,J=5.3Hz,1H),4.68–4.61(m,1H),4.38(t,J=5.8Hz,1H),4.08(s,1H) ,4.00–3.77(m,2H),3.74(s,6H),3.28(dd,J=10.9,4.7Hz,1H),0.76(s,9H),-0.10(s,3H).

[0676] Step 5: Synthesis of (N-(1-((2R,3R,4S,5R)-3-(2-azidoacetamido)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide) (compound 20-5)

[0677] At 21°C, (N-(1-((2R,3R,4S,5R)-3-(2-azidoacetamido)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide) (compound 20-4, 1.0 g, 1.18 mmol, 1.0 eq) was dissolved in tetrahydrofuran (5 mL), and tetrabutylammonium fluoride (2.36 mL, 2.36 mmol, 1 M in) was added at 21°C. The reaction was carried out under nitrogen protection at 21℃ for 3 h (THF, 2.0 eq). The reaction was monitored by TLC until complete. Ethyl acetate (20 mL) was added to the reaction solution, and the organic phase was washed with pure water (20 mL * 3) and saturated NaCl aqueous solution (20 mL * 3). The solution was dried with anhydrous sodium sulfate, filtered, and distilled under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to obtain (N-(1-((2R,3R,4S,5R)-3-(2-azidoacetamido)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide) (compound 20-5,782 mg, yield: 82%).

[0678] 1 H NMR (400MHz, DMSO-d6) δ11.29(s,1H),8.31(d,J=8.6Hz,1H),8.16(d,J=7.6Hz,1H),7.99(d,J=7.7Hz,2 H),7.63(t,J=7.4Hz,1H),7.51(t,J=7.6Hz,2H),7.45–7.24(m,9H),7.18(d,J=7.5Hz,1H),6.91(d,J=8 .6Hz,4H),6.05(d,J=6.9Hz,1H),5.81(d,J=4.9Hz,1H),4.69(q,J=7.2Hz,1H),4.26(q,J=4.8Hz,1H),4 .10(q,J=3.7Hz,1H),3.99–3.83(m,2H),3.75(s,6H),3.39–3.33(m,1H),3.24(dd,J=10.7,3.1Hz,1H).

[0679] Step 6: Synthesis of (N-(1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide) (compound 20-6)

[0680] At 21 °C, (N-(1-((2R,3R,4S,5R)-3-(2-azidoacetamido)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 20-5, 500 mg, 0.68 mmol, 1.0 eq), octadecane-1-yne (compound 14-2, 257 mg, 1.02 mmol, 1.5 eq), CuSO4 (33 mg, 0.21 mmol, 0.3 eq) and sodium vitamin C (203 mg, 1.02 mmol, 1.5 eq) were dissolved in a mixed solution (THF:tBuOH:H2O = 3:1:1, 5 mL), and the reaction was carried out at 30 °C for 3 hours under nitrogen protection. The reaction was monitored by TLC until complete. Saturated sodium bicarbonate aqueous solution (20 mL) and ethyl acetate (20 mL) were added to the reaction solution. After separation, the organic phase was washed with pure water (20 mL*3) and saturated NaCl aqueous solution (20 mL*3), respectively. Anhydrous sodium sulfate was added to the combined organic phase and dried. The crude product was obtained by filtration and vacuum distillation. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 8% B). The eluent was concentrated under vacuum to obtain (N-(1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide) (compound 20-6,606 mg, yield: 91%).

[0681] 1H NMR (400MHz, DMSO-d6) δ11.27(s,1H),8.59(d,J=8.5Hz,1H),8.14(d,J=7.5Hz,1H),7.99(d,J=7.6Hz,2H),7.75(s,1H),7.62(t ,J=7.4Hz,1H),7.51(t,J=7.6Hz,2H),7.37(dd,J=33.0,7.6Hz,4H),7.27(d,J=8.7Hz,5H),7.16(s,1H),6.90(d,J=8.4Hz,4H), 6.09(d,J=6.9Hz,1H),5.87(d,J=4.8Hz,1H),5.12(q,J=16.5Hz,2H),4.67(q,J=7.1Hz,1H),4.32–4.18(m,1H),4.17–4.05(m,1 H),3.74(s,7H),3.37(d,J=4.1Hz,1H),2.59(d,J=7.9Hz,2H),1.55(d,J=7.8Hz,2H),1.25–1.13(m,26H),0.84(t,J=6.6Hz,3H).

[0682] Step 7: Synthesis of ((2R,3S,4R,5R)-5-(4-benzamido-2-oxopyrimidin-1(2H)-yl)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide) (compound N17C)

[0683] Pretreatment: The substrate (N-(1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide) (compound 20-6, 400 mg, 0.41 mmol, 1.0 eq) was azeotropically dehydrated with toluene (5.0 ml * 2).

[0684] Under nitrogen protection, 1H-tetrazole (52.4 mg, 0.73 mmol, 1.8 eq) was dissolved in anhydrous dichloromethane (1.4 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (195 mg, 0.73 mmol, 1.8 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A 2.5 mL solution of pretreated (N-(1-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-3-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)-4-hydroxytetrahydrofuran-2-yl)-2-oxo-1,2-dihydropyrimidin-4-yl)benzamide (compound 20-6) and N,N-diisopropylethylamine (106 mg, 0.82 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol / acetone (1 / 1), elution gradient: 0% B to 6% B). The eluent was concentrated under reduced pressure to give ((2R,3S,4R,5R)-5-(4-benzamido-2-oxopyrimidin-1(2H)-yl)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide) (compound N17C, 410 mg, yield: 85%).

[0685] MS:m / z 1182.6670[M+H] + .

[0686] 1H NMR (400MHz, DMSO-d6) δ11.32(s,1H),8.78(dd,J=13.5,8.6Hz,1H),8.16(d,J=7.7Hz, 1H),7.99(d,J=7.7Hz,2H),7.73(d,J=9.8Hz,1H),7.63(t,J=7.5Hz,1H),7.51(t,J=7. 7Hz,2H),7.41(dd,J=7.6,2.9Hz,2H),7.34–7.21(m,7H),7.19–7.12(m,1H),6.88(dd, J=9.0,2.7Hz,4H),6.22–6.10(m,1H),5.20–5.02(m,2H),4.84(dq,J=37.2,7.2Hz,1H) ,4.31(d,J=35.8Hz,1H),3.94–3.65(m,8H),3.54(ddt,J=24.4,11.1,6.6Hz,2H),3.38 (dd,J=11.6,4.9Hz,1H),3.28(d,J=9.8Hz,1H),2.77(t,J=6.1Hz,1H),2.68(d,J=6.0H z,1H),2.59(td,J=7.6,4.7Hz,2H),1.56(d,J=7.8Hz,2H),1.26–1.18(m,26H),1.13(d d,J=6.8,4.7Hz,6H),1.06(d,J=6.7Hz,3H),0.96(d,J=6.7Hz,3H),0.90–0.75(m,3H).

[0687] 31 P NMR(162MHz,DMSO-d6)δ149.41,147.34.

[0688] Example 21

[0689] Step 1: Synthesis of N-(9-((6aR,8R,9S,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilyoctyl-8-yl)-9H-purine-6-yl)benzamide (compound 21-2)

[0690] Under nitrogen protection and in an ice bath, 1,3-dichloro-1,1,3,3-tetrahydrofuran-2-yl)-9H-purine-6-yl)benzamide (compound 21-1,5 g, 1 eq, 13.46 mmol) was slowly added dropwise to an ultradry pyridine (35 mL) solution. After the addition was complete, the reaction solution was slowly heated to 25 °C and stirred for 23 h. The reaction was monitored by TLC until completion. The reaction solution was concentrated under reduced pressure to remove the solvent. The residue was then diluted with ethyl acetate (50 mL) and poured into dilute hydrochloric acid (120 mL, 2N). Extraction was performed with ethyl acetate (30 mL x 3). The organic phase was washed with dilute hydrochloric acid (50 mL, 2N) and saturated sodium chloride solution (50 mL), respectively. The solution was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was then subjected to normal phase column chromatography (silica gel, mobile phase A: petroleum ether). Mobile phase B: ethyl acetate, elution gradient: 0% B to 60% B), the eluent was concentrated under reduced pressure to give N-(9-((6aR,8R,9S,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisilyoctyl-8-yl)-9H-purine-6-yl)benzamide (compound 21-2, 5.19 g, yield: 63%).

[0691] 1 H NMR (400MHz, DMSO-d6) δ11.24(s,1H),8.69(s,1H),8.56(s,1H),8.11–8.03(m,2H),7.70–7.64(m,1H),7.57(t,J=7.6Hz,2H), 6.03(s,1H),5.70(d,J=4.6Hz,1H),4.85(dd,J=8.1,5.2Hz,1H),4.68(t,J=5.1Hz,1H),4.08–3.94(m,3H),1.12–0.98(m,28H).

[0692] Step 2: Synthesis of (6aR,8R,9S,9aR)-8-(6-benzoylamino-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiosyloctyl-9-yl 1H-imidazolium-1-carboxylic acid ester (compound 21-3)

[0693] N,N'-carbonyldiimidazole (396.23 mg, 2.44 mmol, 1.5 eq.) was added to a solution of N-(9-((6aR,8R,9S,9aS)-9-hydroxy-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiosyloctyl-8-yl)-9H-purine-6-yl)benzamide (compound 21-2, 1 g, 1.63 mmol, 1 eq.) in dichloromethane (10 mL) at 25 °C. The reaction mixture was stirred at 25 °C for 1 h. TLC monitoring showed that the reaction was complete. The reaction solution was concentrated under reduced pressure to remove most of the solvent, and then directly subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: acetone, elution gradient: 0% B to 60% B). The eluent was concentrated under reduced pressure to give (6aR,8R,9S,9aR)-8-(6-benzoylamino-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiosyloctyl-9-yl 1H-imidazol-1-carboxylic acid ester (compound 21-3, 1.1 g, yield: 95%).

[0694] MS:m / z 708.36[M+H] + .

[0695] 1 H NMR(400MHz,DMSO-d6)δ11.31(s,1H),8.68(s,1H),8.62(s,1H),8.48(s,1H),8.11–8 .04(m,2H),7.71–7.64(m,2H),7.62–7.54(m,2H),7.17–7.13(m,1H),6.50(d,J=1.1Hz ,1H),6.23–6.14(m,1H),5.45(dd,J=8.9,5.5Hz,1H),4.24–4.18(m,1H),4.10(dd,J=1 2.9, 4.0Hz, 1H), 4.03 (dd, J=12.9, 3.1Hz, 1H), 1.17–1.01 (m, 21H), 0.89–0.79 (m, 7H).

[0696] Step 3: Synthesis of 2-(2-(2-(((((6aR,8R,9R,9aR)-8-(6-benzamido-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisili-9-yl)oxy)carbonyl)amino)ethoxy)ethoxy)acetic acid (compound 21-4)

[0697] To a solution of compound (6aR,8R,9S,9aR)-8-(6-benzoylamino-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiosyloctyl-9-yl 1H-imidazolium-1-carboxylic acid ester (compound 21-3, 0.5 g, 0.706 mmol, 1.0 eq.) in N,N-dimethylformamide (4 mL), 2-(2-(2-aminoethoxy)ethoxy)acetic acid (138.29 mg, 0.848 mmol, 1.2 eq.) was added. The reaction mixture was then purged with nitrogen three times and stirred at 80 °C for 5 h. TLC monitoring showed that the reaction was complete. The reaction mixture was directly purified by reverse-phase chromatography (C18, mobile phase A: water (0.1% TFA), mobile phase B: acetonitrile, elution gradient: 5% B to 95% B). The eluent was concentrated at room temperature to remove some acetonitrile and then lyophilized to give 2-(2-(2-((((6aR,8R,9R,9aR)-8-(6-benzamido-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisila-9-yl)oxy)carbonyl)amino)ethoxy)ethoxy)acetic acid (compound 21-4, 370 mg, yield: 65%).

[0698] MS:m / z 803.34 [M+H] + .

[0699] Step 4: Synthesis of (6aR,8R,9R,9aR)-8-(6-benzamido-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiazine-indole-9-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 21-5)

[0700] Add the compound 2-(2-(2-(((((6aR,8R,9R,9aR)-8-(6-benzamido-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadisili-9-yl)oxy)carbonyl)amino)ethoxy)ethoxy)acetic acid (compound 21-4, 1.25 g, 1.56 mmol, 1 eq.) to a solution of N,N-dimethylformamide (24 mL). Hexadecane-1-amine (375.86 mg, 1.56 mmol, 1 eq.), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (298.41 mg, 1.56 mmol, 1 eq.), 1-hydroxybenzotriazole (210.34 mg, 1.56 mmol, 1 eq.), and N,N-diisopropylethylamine (603.56 mg, 4.67 mmol, 3 eq.) were added. The mixture was then purged with nitrogen three times and stirred at 35 °C for 16 h. The reaction was monitored by TLC until complete. The reaction solution was diluted with 200 mL of water and extracted with ethyl acetate (60 mL * 3). The organic phases were combined and washed once with saturated sodium chloride aqueous solution (100 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to obtain the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to obtain (6aR,8R,9R,9aR)-8-(6-benzamido-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxadiazine-indole-9-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 21-5, 1.08 g, yield: 65%).

[0701] 1H NMR(400MHz, DMSO-d6)δ11.27(s,1H),8.65(d,J=11.9Hz,2H),8.10–8.03(m,2H),7.70–7.65(m,1H),7.6 2–7.54(m,3H),6.25–6.17(m,1H),5.89–5.80(m,1H),5.78(s,1H),5.29–5.18(m,1H),4.06(dd,J=13.1, 5.0Hz,1H),3.99(d,J=10.3Hz,2H),3.86(s,2H),3.63–3.51(m,4H),3.44(d,J=3.0Hz,2H),3.24–3.12(m ,2H),3.12–3.02(m,2H),1.44–1.35(m,2H),1.29–1.19(m,26H),1.15–0.95(m,28H),0.89–0.84(m,3H).

[0702] Step 5: Synthesis of (2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-4-hydroxy-5-hydroxymethyltetrahydrofuran-3-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 21-6)

[0703] Tetrabutylammonium fluoride (0.78 mL, 0.779 mmol, 2.5 eq., 1 M) was added to a solution of (6aR,8R,9R,9aR)-8-(6-benzamido-9H-purin-9-yl)-2,2,4,4-tetraisopropyltetrahydro-6H-furano[3,2-f][1,3,5,2,4]trioxisindo-9-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 21-5, 0.32 g, 0.312 mmol, 1.0 eq.) in N,N-dimethylformamide (5 mL) at 0 °C. The reaction mixture was then stirred at 20 °C for 1 h. The reaction was monitored by TLC until completion. The reaction solution was concentrated under reduced pressure to obtain the crude product, which was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to obtain (2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-4-hydroxy-5-hydroxymethyltetrahydrofuran-3-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 21-6, 150 mg, yield: 61%).

[0704] 1H NMR(400MHz, DMSO-d6)δ11.25(s,1H),8.77(d,J=9.1Hz,2H),8.09–8.03(m,2H),7.70–7.60(m,2H),7.60 –7.53(m,2H),7.40(t,J=5.6Hz,1H),6.26(d,J=5.8Hz,1H),5.67–5.58(m,2H),5.19(t,J=5.4Hz,1H),4.5 1(q,J=5.0Hz,1H),4.07–4.01(m,1H),3.85(s,2H),3.78–3.70(m,1H),3.65–3.58(m,1H),3.57–3.49(m, 4H),3.39(t,J=6.1Hz,2H),3.15–3.03(m,4H),1.44–1.34(m,2H),1.27–1.18(m,26H),0.90–0.82(m,3H).

[0705] Step 6: Synthesis of (2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compounds 21-7)

[0706] At 21°C, (2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-4-hydroxy-5-hydroxymethyltetrahydrofuran-3-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 21-6, 500 mg, 0.64 mmol, 1.0 eq) was dissolved in pyridine (5 mL) and azeotropically twice. It was then dissolved again in pyridine (3 mL), and 4,4'-dimethoxytriphenylchloromethane (260 mg, 0.08 mmol, 1.2 eq) was added at 0°C. The reaction was carried out at 21°C under nitrogen protection for 2 h. The reaction was monitored by TLC until it was complete. Saturated NaHCO3 (10 mL) was added to the reaction solution to quench the reaction. Ethyl acetate (30 mL), pure water (20 mL x 3), and saturated NaCl (20 mL x 2) were added sequentially to wash the organic phase. The organic phases were combined, dried over anhydrous sodium sulfate, and filtered to obtain the crude product. The crude product was then subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to obtain (2R,3R,4R,5R)-2-(6 -Benzamido-9H-purin-9-yl)-4-hydroxy-5-hydroxymethyltetrahydrofuran-3-yl(2R,3R,4R,5R)-2-(6-Benzamido-9H-purin-9-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (Compound 21-7, 352 mg, yield: 52%).

[0707] 1H NMR (400MHz, DMSO-d6) δ11.24(s,1H),8.68(s,1H),8.62(s,1H),8.07–8.02(m,2H),7.68–7.59(m,2H),7.55(t,J=7.6Hz,2H ),7.42(t,J=5.7Hz,1H),7.37–7.32(m,2H),7.29–7.13(m,7H),6.81(dd,J=8.9,4.9Hz,4H),6.25(d,J=4.5Hz,1H),5.77(t, J=5.1Hz,1H),5.65(d,J=5.6Hz,1H),4.72(t,J=5.6Hz,1H),4.11(d,J=4.9Hz,1H),3.83(s,2H),3.71(d,J=1.3Hz,7H),3.58 –3.49(m,4H),3.41(d,J=12.0Hz,2H),3.21–3.01(m,4H),1.36(d,J=7.5Hz,2H),1.21(d,J=5.9Hz,26H),0.89–0.79(m,3H).

[0708] Step 7: Synthesis of (2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphoryl)oxy)tetrahydrofuran-3-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound N19A)

[0709] Pretreatment: The substrate (2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-4-hydroxy-5-hydroxymethyltetrahydrofuran-3-yl(2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (compound 21-7, 300 mg, 0.28 mmol, 1.0 eq) was azeotropically dehydrated with toluene (3.0 ml * 2).

[0710] Under nitrogen protection, 1H-tetrazole (36.0 mg, 0.50 mmol, 1.8 eq) was dissolved in anhydrous dichloromethane (1.4 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (155 mg, 0.50 mmol, 1.8 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A solution (3 mL) of pretreated (2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-4-hydroxy-5-hydroxymethyltetrahydrofuran-3-yl(2R,3R,4R,5R)-2-(6-benzamido-9H-purin-9-yl)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-3-yl(2-(2-(2-(hexadecylamino)-2-oxoethoxy)ethoxy)ethyl)carbamate (72 mg, 0.55 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol / acetone (1 / 1), elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to give ((2R,3S,4R,5R)-5-(4-benzamido-2-oxopyrimidin-1(2H)-yl)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(2-(4-hexadecyl-1H-1,2,3-triazol-1-yl)acetamido)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide) (compound N19A, 301 mg, yield: 85%).

[0711] MS:m / z 1286.71 [M+H] + .

[0712] 1H NMR(400MHz,DMSO-d6)δ11.25(s,1H),8.67–8.59(m,2H),8.08–8.00(m,2H),7.68–7.49(m,5H),7.44–7.00(m,9 H),6.80(dd,J=8.5,5.4Hz,4H),6.28(dd,J=17.4,5.0Hz,1H),4.27(dd,J=10.8,5.0Hz,1H),3.82(d,J=1.6Hz,2H ),3.71(d,J=1.5Hz,6H),3.64–3.32(m,13H),3.28–3.10(m,2H),3.05(q,J=6.7Hz,2H),2.77(t,J=5.9Hz,1H),2 .61(q,J=5.7Hz,1H),1.36(q,J=6.4,5.8Hz,2H),1.21(d,J=6.2Hz,26H),1.15–0.99(m,12H),0.90–0.79(m,3H).

[0713] 31 P NMR(162MHz,DMSO-d6)δ149.54.

[0714] Example 22

[0715] Step 1: Synthesis of 2-(2-(2-(eicosyloxy)ethoxy)ethoxy)-1-ethanol (compound 22-2)

[0716] Potassium hydroxide (790 mg, 14.1 mmol, 1.1 eq) was dissolved in 2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-1-ol) (6 g, 64.1 mmol, 5 eq), followed by the sequential addition of 1,4-dioxane (5 mL), 1-bromodocoane (compound 1-1, 5 g, 12.8 mmol, 1.0 eq), and tetrabutylammonium bromide (206 mg, 0.64 mmol, 0.05 eq). The reaction temperature was raised to 100 °C, and the reaction was continued for 1 hour under nitrogen protection. After 1 hour, the reaction was monitored by TLC to ensure complete reaction. Water (20 mL) and dichloromethane (20 mL) were added for extraction. The aqueous phase was extracted with DCM (20 mL). The combined organic phases were washed sequentially with saturated sodium chloride aqueous solution (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to remove excess solvent. Normal-phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 30% B), followed by concentration of the eluent under reduced pressure, yielded 2-(2-(2-(dococoyloxy)ethoxy)ethoxy)-1-ethanol (compound 22-2, 4.3 g, yield: 73%).

[0717] 1 H NMR (400MHz, DMSO-d6) δ4.56(t,J=5.4Hz,1H),3.55–3.32(m,14H),1.46(s,2H),1.23(s,38H),0.85(t,J=6.2Hz,3H).

[0718] Step 2: Synthesis of 2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)carbamate (compound 22-4)

[0719] At 0 °C, 2-(2-(2-(dococooxy)ethoxy)ethoxy)-1-ethanol (compound 22-2, 504 mg, 1.1 mmol, 1.1 eq) and triphosgene (506 mg, 1.7 mmol, 1.7 eq) were dissolved in anhydrous THF (15 mL), followed by the slow addition of an ultradry tetrahydrofuran (1 mL) solution of pyridine (158 mg, 2 mmol, 2.0 eq). The reaction mixture was stirred for 30 minutes at 25 °C, and after adding anhydrous THF (15 mL), it was used directly in the next step.

[0720] At 0°C, N-hydroxysuccinimide (345 mg, 3 mmol, 3.0 eq) and pyridine (237 mg, 3 mmol, 3.0 eq) were added sequentially to the above solution. The reaction system was heated to room temperature and stirred for 30 minutes. The reaction was monitored by TLC until complete. The residue was dissolved in ethyl acetate (20 mL) and washed sequentially with saturated sodium bicarbonate aqueous solution (20 mL), 0.1 M HCl (20 mL), and saturated sodium chloride aqueous solution (20 mL). The organic phase was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to remove most of the solvent. The filtrate was then dried under vacuum for 1 hour to remove the residual solvent, yielding a pale yellow, foamy active ester intermediate (compound 22-3, 1.2 g).

[0721] At 0 °C, 1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-hydroxytetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione (compound 9-6, 545 mg, 1 mmol, 1 eq) was dissolved in anhydrous THF (20 mL). Then, N,N-diisopropylethylamine (387 mg, 3 mmol, 3 eq) and a tetrahydrofuran solution of the active ester intermediate (compound 22-3) (10 mL) were added sequentially. The mixture was then brought to room temperature and stirred. After the reaction was completed by TLC monitoring, the solvent was removed by concentration under reduced pressure to obtain the crude product. Normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: acetone:methanol = 1:1, elution gradient: 0% B to 3% B), followed by concentration of the eluent under reduced pressure, yielded 2-(2-(2-(dococoyloxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)carbamate (compound 22-4, 650 mg, yield: 63%).

[0722] 1 H NMR (400MHz, DMSO-d6) δ11.35(s,1H),7.66(d,J=8.1Hz,1H),7.39(d,J=7.7Hz,2H),7.31(t,J=7.6Hz,2H), 7.29–7.18(m,6H),6.93–6.86(m,4H),5.86(d,J=7.5Hz,1H),5.60(d,J=4.9Hz,1H),5.40(d,J=8.1Hz,1H), 4.39–4.30(m,1H),4.20–4.11(m,1H),4.07(t,J=4.7Hz,2H),4.02–3.94(m,1H),3.74(s,6H),3.61–3.34(m ,12H),3.29–3.22(m,1H),3.21–3.12(m,1H),1.51–1.41(m,2H),1.23(d,J=1.8Hz,38H),0.89–0.81(m,3H).

[0723] Step 3: Synthesis of 2-(2-(2-(eicosicoalkoxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphonocyclic)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)carbamate (compound N20U)

[0724] Pretreatment: The substrate 2-(2-(2-(eicosethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)carbamate (compound 22-4, 50 mg, 0.049 mmol, 1.0 eq) was azeotropically dehydrated with toluene (1.0 ml * 2).

[0725] Under nitrogen protection, 1H-tetrazole (6.8 mg, 0.097 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (0.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (29.2 mg, 0.97 mmol, 2.0 eq) was added, and the mixture was stirred at 25 °C for 1 hour. A 1 mL solution of pretreated 2-(2-(2-(eicosethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)carbamate (compound 22-4) and N,N-diisopropylethylamine (12.6 mg, 0.097 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol / acetone (1 / 1), elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to give 2-(2-(2-(dococoyloxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphonoheteroyl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)carbamate (compound N20U, 30 mg, yield: 50%).

[0726] MS: m / z 1247.78 [M+NH3] + .

[0727] 1H NMR (400MHz, DMSO-d6) δ11.41(s,1H),7.71(dd,J=8.2,5.6Hz,1H),7.51(dd,J=17.7,8.7Hz,1H),7.39(dd,J=7.8,3.4Hz,2H),7.28( ddq,J=20.6,8.4,3.7Hz,7H),6.92–6.82(m,4H),5.90(t,J=6.2Hz,1H),5.44(dd,J=10.1,8.4Hz,1H),4.60–4.40(m,1H),4.44–4.27 (m,1H),4.08(ddt,J=19.6,8.0,4.2Hz,2H),3.73(d,J=1.7Hz,7H),3.69–3.30(m,16H),3.25(dt,J=20.6,5.9Hz,2H),2.75(t,J=6.0 Hz,1H),2.62(t,J=6.0Hz,1H),1.46(t,J=6.8Hz,2H),1.22(s,26H),1.14–1.03(m,9H),0.95(d,J=6.7Hz,3H),0.84(t,J=6.7Hz,3H).

[0728] 31 P NMR(162MHz,DMSO-d6)δ149.58,147.64.

[0729] Example 23

[0730] Step 1: Synthesis of 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)-1-ethanol (compound 23-1)

[0731] Potassium hydroxide (408 mg, 7.3 mmol, 1.1 eq) was dissolved in 2,2'-(ethane-1,2-diylbis(oxy))bis(ethane-1-ol) (4.9 g, 32.8 mmol, 5 eq), followed by the sequential addition of 1,4-dioxane (3 mL), 1-bromohexadecane (2 g, 6.6 mmol, 1.0 eq), and tetrabutylammonium bromide (106 mg, 0.33 mmol, 0.05 eq). The reaction temperature was raised to 100 °C, and the reaction was continued for 1 hour under nitrogen protection. After 1 hour, the reaction was monitored by TLC to ensure complete reaction. Water (20 mL) and dichloromethane (20 mL) were added for extraction. The aqueous phase was extracted with DCM (20 mL). The combined organic phases were washed sequentially with saturated sodium chloride aqueous solution (20 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to remove excess solvent. Normal-phase column chromatography (silica gel, mobile phase A: petroleum ether, mobile phase B: ethyl acetate, elution gradient: 0% B to 40% B), followed by concentration of the eluent under reduced pressure, yielded 2-(2-(2-(hexadecoxy)ethoxy)ethoxy)-1-ethanol (compound 23-1, 1.9 g, yield: 77%).

[0732] 1 H NMR (400MHz, DMSO-d6) δ4.56 (t, J = 5.5 Hz, 1H), 3.53–3.31 (m, 15H), 1.47 (p, J = 6.7 Hz, 2H), 1.24 (s, 27H), 0.85 (t, J = 6.7 Hz, 3H).

[0733] Step 2: Synthesis of 2-(2-(2-(hexadecoxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsilyl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)carbamate (compound 23-3)

[0734] At 0 °C, 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)-1-ethanol (compound 23-1, 342 mg, 0.92 mmol, 1.2 eq) and triphosgene (465 mg, 1.56 mmol, 1.7 eq) were dissolved in anhydrous tetrahydrofuran (5 mL), followed by the slow addition of a 1 mL solution of ultradry tetrahydrofuran containing pyridine (145 mg, 1.84 mmol, 2.0 eq). The reaction mixture was stirred at 25 °C for 30 minutes and used directly in the next step.

[0735] At 0°C, N-hydroxysuccinimide (317 mg, 2.76 mmol, 3.0 eq) and pyridine (218 mg, 2.76 mmol, 3.0 eq) were added sequentially to the above solution. The reaction system was heated to room temperature and stirred for 30 minutes. The reaction was monitored by TLC until complete. The residue was dissolved in ethyl acetate (10 mL) and washed sequentially with saturated sodium bicarbonate aqueous solution (10 mL), 0.1 M HCl (10 mL), and saturated sodium chloride aqueous solution (10 mL). The organic phase was dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to remove most of the solvent. The filtrate was then dried under vacuum for 1 hour to remove the residual solvent, yielding the active ester intermediate (compound 23-2, 1.2 g).

[0736] At 0 °C, (1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione) (compound 20-1, 500 mg, 0.76 mmol, 1 eq) was dissolved in anhydrous tetrahydrofuran (10 mL). Then, N,N-diisopropylethylamine (294 mg, 2.28 mmol, 3 eq) and a tetrahydrofuran solution of the active ester intermediate (compound 23-2) were added sequentially. The mixture was then brought to room temperature and stirred continuously. The reaction was monitored by TLC. After the reaction was completed, the solvent was removed by concentration under reduced pressure to obtain the crude product. The crude product was then subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to give 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsilyl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)carbamate (compound 23-3,736 mg, yield: 92%).

[0737] 1H NMR(400MHz,DMSO-d6)δ11.31(s,1H),8.68(s,1H),8.62(s,1H),8.48(s,1H),8.11–8 .04(m,2H),7.71–7.64(m,2H),7.62–7.54(m,2H),7.17–7.13(m,1H),6.50(d,J=1.1Hz ,1H),6.23–6.14(m,1H),5.45(dd,J=8.9,5.5Hz,1H),4.24–4.18(m,1H),4.10(dd,J=1 2.9, 4.0Hz, 1H), 4.03 (dd, J=12.9, 3.1Hz, 1H), 1.17–1.01 (m, 21H), 0.89–0.79 (m, 7H).

[0738] Step 3: Synthesis of 2-(2-(2-(hexadecoxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)carbamate (compound 23-4)

[0739] At 25°C, 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsilyl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)carbamate (compound 23-3,736 mg, 0.69 mmol, 1.0 eq) was dissolved in anhydrous tetrahydrofuran (5 mL), and then tetrabutylammonium fluoride (2.1 mL, 2.1 mmol, 3.0 eq, 1 M in THF) was slowly added dropwise. The reaction mixture was stirred for 30 minutes. After 30 minutes, the reaction was monitored by TLC until it was complete. Ethyl acetate (10 mL) and water (10 mL) were added for extraction. The organic phase was washed successively with water (10 mL), saturated sodium chloride aqueous solution (10 mL), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to remove the organic solvent, yielding the crude product. The crude product was subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was concentrated under reduced pressure to give 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)carbamate (compound 23-4, 510 mg, yield: 78%).

[0740] 1 H NMR (400MHz, DMSO-d6) δ11.35(s,1H),7.66(d,J=8.1Hz,1H),7.42–7.18(m,9H),6.90(d,J=8.5Hz,4 H),5.87(d,J=7.5Hz,1H),5.60(d,J=5.0Hz,1H),5.40(d,J=7.8Hz,1H),4.40–4.30(m,1H),4.21–4. 11(m,1H),4.10–4.03(m,2H),4.01–3.94(m,1H),3.74(s,6H),3.60–3.32(m,13H),3.26(dd,J=10.6 ,4.6Hz,1H),3.17(dd,J=10.4,3.1Hz,1H),1.51–1.40(m,2H),1.23(s,26H),0.85(t,J=6.7Hz,3H).

[0741] Step 4: Synthesis of 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphonoheteroyl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)carbamate (compound N21U)

[0742] Pretreatment: The substrate 2-(2-(2-(hexadecoxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)carbamate (compound 23-4, 50 mg, 0.053 mmol, 1.0 eq) was azeotropically dehydrated with toluene (1.0 ml * 2).

[0743] Under nitrogen protection, 1H-tetrazole (7.4 mg, 0.106 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (0.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (32 mg, 0.106 mmol, 2.0 eq) was added, and the mixture was stirred at 30 °C for 1 hour. A solution (1 mL) of pretreated 2-(2-(2-(hexadecoxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)carbamate (compound 23-4) and N,N-diisopropylethylamine (14 mg, 0.106 mmol, 2.0 eq) in dichloromethane was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane (0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)ethyl((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-(((2-cyanoethoxy)(diisopropylamino)phosphonoheteroyl)oxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)carbamate (compound N21U, 37 mg, yield: 61%).

[0744] MS:m / z 1163.68 [M+H] + .

[0745] 1 H NMR (400MHz, DMSO-d6) δ11.41(s,1H),7.71(dd,J=8.2,5.9Hz,1H),7.52(dd,J=18.6,8.8Hz,1H),7.39(dd,J=7.8,3.0 Hz,2H),7.35–7.20(m,7H),6.92–6.84(m,4H),5.90(t,J=6.3Hz,1H),5.44(t,J=9.2Hz,1H),4.60–4.41(m,1H),4.44– 4.27(m,1H),4.15–3.99(m,2H),3.73(d,J=1.6Hz,7H),3.70–3.32(m,27H),3.31–3.17(m,2H),2.76(t,J=6.0Hz,1H), 2.62(t,J=5.9Hz,1H),1.51–1.40(m,2H),1.23(s,26H),1.14–1.03(m,9H),0.95(d,J=6.7Hz,3H),0.89–0.80(m,3H).

[0746] 31 P NMR(162MHz,DMSO-d6)δ149.56,147.63.

[0747] Example 24

[0748] Step 1: Synthesis of 4-(((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)amino)-4-oxobutyric acid (compound 24-1)

[0749] At room temperature (22°C), (1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione) (compound 20-1, 2.2 g, 3.3 mmol, 1.0 eq) was dissolved in anhydrous dichloromethane (20 mL), followed by the addition of succinic anhydride (334 mg, 3.3 mmol, 1.0 eq) and triethylamine (675 mg, 6.7 mmol, 2.0 eq). After purging with nitrogen, the mixture was stirred at room temperature for 5 hours. TLC showed that the reaction was essentially complete, and the reaction solution was used directly for the next step without further treatment.

[0750] Step 2: Synthesis of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)-4-(2-eicosanohydrazido)-4-oxobutyramide (compound 24-2)

[0751] At room temperature, to a solution of 4-(((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)amino)-4-oxobutyric acid (compound 24-1, crude) in anhydrous dichloromethane (20 mL, the reaction solution from the previous step), docosanoyl hydrazine (12-2, 1.17 g, 3.3 mmol, 1.0 eq), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (759 mg, 4.0 mmol, 1.2 eq), and 1-hydroxybenzotriazole (535 mg) were added sequentially. The reaction mixture (4.0 mmol, 1.2 eq) was stirred for 19 h. TLC showed that the reaction was almost complete. The reaction mixture was concentrated and dried to obtain the crude product. Normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B) was performed. The eluent was concentrated under reduced pressure to give N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)-4-(2-eicosanohydrazido)-4-oxobutyramide (compound 24-2, 1.6 g, two-step yield: 45%).

[0752] 1H NMR (400MHz, DMSO-d6) δ11.43(d,J=2.3Hz,1H),9.73(d,J=1.9Hz,1H),9.66(d,J=1.8Hz,1H),8.13(d,J=8.8Hz,1H), 7.72(d,J=8.1Hz,1H),7.46–7.23(m,9H),6.97–6.87(m,4H),5.86(d,J=6.6Hz,1H),5.52(dd,J=8.1,2.1Hz,1H),4.65 (q,J=7.1Hz,1H),4.31(dd,J=6.4,4.1Hz,1H),4.05–3.97(m,1H),3.76(s,6H),3.30–3.16(m,2H),2.50–2.33(m,4H), 2.10(t,J=7.2Hz,2H),1.51(t,2H),1.31–1.23(m,36H),0.87(t,J=6.5Hz,3H),0.81(s,9H),-0.03(d,J=26.9Hz,6H).

[0753] Step 3: Synthesis of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-(2-eicosanohydrazido)-4-oxobutyramide (compound 24-3)

[0754] Under ice bath conditions, tetrabutylammonium fluoride (3.65 mL, 3.65 mmol, 2.5 eq) was added dropwise to a tetrahydrofuran (16 mL) solution of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)-4-(2-eicosanohydrazido)-4-oxobutyramide (compound 24-2, 1.6 g, 1.46 mmol, 1.0 eq). After the addition was complete, the temperature was slowly raised to 25 °C. Continue stirring for 1 hour. TLC showed the reaction was complete. The reaction solution was concentrated and dried to obtain the crude product. Normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B) was performed. The eluent was concentrated under reduced pressure to give N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-(2-eicosanohydrazido)-4-oxobutyramide (compound 24-3, 950 mg, yield: 66%).

[0755] 1 H NMR (400MHz, DMSO-d6) δ11.35(d,J=2.3Hz,1H),9.72(d,J=2.0Hz,1H),9.66(d,J=1.9Hz,1H),8.03(d,J=8.5Hz,1H),7. 66(d,J=8.1Hz,1H),7.45–7.20(m,9H),6.92(dd,J=9.3,2.6Hz,4H),5.89(d,J=7.9Hz,1H),5.68(d,J=4.7Hz,1H),5.42( dd,J=8.1,2.2Hz,1H),4.70–4.55(m,1H),4.22–4.13(m,1H),4.03(dd,J=4.9,2.2Hz,1H),3.76(s,6H),3.24(ddd,J=33 .1,10.5,3.9Hz,2H),2.49–2.29(m,4H),2.10(t,J=7.4Hz,2H),1.49(d,J=8.0Hz,2H),1.25(s,36H),0.91–0.83(m,3H).

[0756] Step 4: Synthesis of (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(4-(2-eicosicohydrazido)-4-oxobutanylamino)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N22U)

[0757] Pretreatment: The substrate N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-(2-eicosicohydrazido)-4-oxobutyramide (compound 24-3, 300 mg, 0.3 mmol, 1.0 eq) was azeotropically dehydrated with toluene (5.0 ml * 2).

[0758] Under nitrogen protection, 1H-tetrazole (42.8 mg, 0.6 mmol, 2.0 eq) was dissolved in anhydrous dichloromethane (1.2 mL). Under nitrogen protection, bis(diisopropylamino)(2-cyanoethoxy)phosphine (184.1 mg, 0.6 mmol, 2.0 eq) was added, and the mixture was stirred at 25 °C for 1 hour. A 3 mL solution of pretreated N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-4-(2-eicosanohydrazido)-4-oxobutyramide (compound 24-3) and N,N-diisopropylethylamine (79.0 mg, 0.6 mmol, 2.0 eq) in tetrahydrofuran was added to the reaction mixture. The reaction was continued at 25 °C under nitrogen protection for 2 hours. The reaction was monitored by TLC until it was complete. The mixture was then directly subjected to normal-phase column chromatography (silica gel, mobile phase A: petroleum ether / dichloromethane (1 / 1, 0.1% triethylamine), mobile phase B: methanol, elution gradient: 0% B to 3% B). The eluent was concentrated under reduced pressure to give (2R,3S,4R,5R)-2-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-5-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-(4-(2-eicosodehydrazido)-4-oxobutanylamino)tetrahydrofuran-3-yl(2-cyanoethyl)diisopropylphosphonamide (compound N22U, 210 mg, yield: 58%).

[0759] MS: m / z 1199.74 [M+NH3] + .

[0760] 1H NMR (400MHz, DMSO-d6) δ11.41(s,1H),9.70(dd,J=4.0,1.9Hz,1H),9.64(d,J=1.9Hz,1H),8.18(d,J=8.5,6.5Hz,1H) ,7.66(d,J=8.2,1.7Hz,1H),7.45–7.17(m,9H),6.95–6.80(m,4H),5.92(dd,J=7.8,2.6Hz,1H),5.48–5.36(m,1H),4. 91–4.70(m,1H),4.50–4.09(m,2H),3.93–3.63(m,8H),3.63–3.42(m,2H),3.32–3.15(m,2H),2.80–2.61(m,2H),2.47 –2.25(m,4H),2.08(t,J=7.6Hz,2H),1.48(t,J=7.3Hz,2H),1.23(s,36H),1.14–0.93(m,12H),0.85(t,J=6.8Hz,3H).

[0761] 31 P NMR(162MHz,DMSO-d6)δ149.19,147.28.

[0762] Example 25

[0763] Step 1: Synthesis of 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)acetic acid (compound 25-1)

[0764] 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)-1-ethanol (compound 23-1, 3.8 g, 10.2 mmol, 1 eq) was dissolved in a mixture of dichloromethane (100 mL) and saturated NaHCO3 (25 mL), followed by the sequential addition of KBr (238 mg, 2 mmol, 0.2 eq) and TEMPO (31.2 mg, 0.2 mmol, 0.02 eq). Trichloroisocyanuric acid (4.7 g, 20.4 mmol, 2.0 eq) was slowly added in portions at 0 °C, and the reaction was allowed to proceed at room temperature for 3 hours. After the reaction was complete, isopropanol was slowly added dropwise to quench the reaction, resulting in a weakly acidic pH. Water and dichloromethane were added for extraction. The aqueous phase was extracted twice with dichloromethane. The combined organic phases were washed successively with saturated sodium chloride aqueous solution, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain the crude product. This crude product was then subjected to normal-phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 5% B). The eluent was concentrated under reduced pressure to give 2-(2-(2-(hexadecyloxy)ethoxy)ethoxyacetic acid (compound 25-1, 1.8 g, yield: 45%).

[0765] Step 2: Synthesis of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)-2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)acetamide (compound 25-2)

[0766] 2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)acetic acid (compound 25-1, 698 mg, 1.8 mmol, 1.5 eq) was dissolved in dichloromethane (10 mL), and N,N-diisopropylethylamine (468 mg, 3.6 mmol, 3.0 eq) was added. After the reaction solution was completely dissolved, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (346 mg, 1.8 mmol, 1.5 eq) was added sequentially at 0 °C. -Hydroxybenzotriazole (243 mg, 1.8 mmol, 1.5 eq) was added. After the addition was complete, the reaction temperature was raised to 25 °C, and the reaction was continued for 30 min under nitrogen protection. Then, (1-((2R,3R,4S,5R)-3-amino-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)tetrahydrofuran-2-yl)pyrimidin-2,4(1H,3H)-dione) (compound 20-1,800) was added. The reaction was continued at 25°C under nitrogen protection (mg, 1.2 mmol, 1.0 eq). After the reaction was complete as monitored by TLC, saturated sodium bicarbonate aqueous solution and dichloromethane (10 mL) were added for extraction. The aqueous phase was extracted once with dichloromethane (10 mL). The organic phases were combined, washed successively with saturated sodium chloride aqueous solution, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure to remove the organic phase, yielding the crude product. The crude product was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol / acetone (1 / 1)). Elution gradient: 0% B to 2% B), the eluent was concentrated under reduced pressure to give N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)-2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)acetamide (compound 25-2, 1.1 g, yield: 89%).

[0767] 1H NMR (400MHz, DMSO-d6) δ11.37(d,J=2.2Hz,1H),7.70(d,J=8.1Hz,1H),7.44–7.19(m,10H),6.89(d,J=8.6Hz,4 H),5.84(d,J=6.8Hz,1H),5.54(dd,J=8.1,2.2Hz,1H),4.63(q,J=7.3Hz,1H),4.29–4.23(m,1H),4.03–3.97(m, 1H),3.94(s,1H),3.92(s,1H),3.73(s,6H),3.62–3.44(m,8H),3.36(d,J=6.6Hz,2H),3.25(dd,J=14.8,10.1H z,2H),1.49–1.41(m,2H),1.24–1.20(m,26H),0.84(t,J=6.7Hz,3H),0.80(s,9H),-0.01(s,3H),-0.08(s,3H).

[0768] Step 3: Synthesis of N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)-4-hydroxytetrahydrofuran-3-yl)-2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)acetamide (compound 25-3)

[0769] At 25°C, N-((2R,3R,4S,5R)-5-((bis(4-methoxyphenyl)(phenyl)methoxy)methyl)-4-((tert-butyldimethylsiloxy)-2-(2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-3-yl)-2-(2-(2-(hexadecyloxy)ethoxy)ethoxy)acetamide (compound 25-2, 1.1 g, 1.1 mmol, 1.0 eq) was dissolved in anhydrous tetrahydrofuran (5 mL), and then tetrabutylammonium fluoride (3.3 mL, 3.3 mmol, 3.0 eq, 1 M in) was slowly added dropwise. THF was used to stir the reaction mixture. After 1 hour, the reaction was monitored by TLC until it was complete. Ethyl acetate (10 mL) and water (10 mL) were added for extraction. The organic phase was washed with water, then with saturated sodium chloride solution, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated under reduced pressure to remove the organic solvent, yielding the crude product. The crude product was then subjected to normal phase column chromatography (silica gel, mobile phase A: dichloromethane, mobile phase B: methanol, elution gradient: 0% B to 2% B). The eluent was ...

Claims

Nucleotide-lipid conjugate monomers or their pharmaceutically acceptable salts, tautomers, enantiomers or stereoisomers, wherein, The nucleotide-lipid conjugate monomer comprises a structure represented by Formula (I), in, Z 1 Z 2 Z 3 Z 4 Each of them is independently selected from -O-, -S-, and -N(R). a )-, -C(=O)-, -OC(=O)-, -C(=O)O-, -OC(=O)NR a -、-C(=O)NR a -、-C(=O)NR a NR a C(=O)-、-NR a C(=O)O-、-NR a C(=O)-、-NR a C(=O)NR a -、-OC 1-6 Alkylene-, -NR a C 1-6 Alkylene-, -OC(=O)NR a C 1-6 Alkylene-, -NR a C(=O)OC 1-6 Alkylene-, -NR a C(=O)C 1-6 Alkylene-,-C(=O)NR a C 1-6 Alkylene-, -NR a C(=O)NR a C 1-6 Alkylene -, -(CH2OCH2) t -、-C 1-6 Alkylene (CH2OCH2) t -、-(CH2OCH2) t C 1-6 alkylene-, -C 1-6 Alkylene (CH2OCH2) t C 1-6 Alkylene-,-C(=O)NR a -C 1-6 Alkylene-NR a -C 1-6 Alkylene-NR a C(=O)-、 C 3-9 Cycloalkylene, 4-9 membered heterocyclic, 5-9 membered heteroarylene, and any combination thereof, or, Z 1 Z 2 Z 3 Z 4 One, two, or three of them are missing; R a each independently selected from H and C 1-6 alkyl; t can be 0, 1, 2, 3, 4, 5, or 6; R 1 selected from C 12-32 alkyl, C 12-32 alkenyl and C 12-32 alkynyl, said C 12-32 alkyl, C 12-32 alkenyl and C 12- 32 alkynyl is optionally substituted with one or more groups selected from H, halogen, OH, CN, NO2, COOH, -OC 1-6 alkyl, -NHC 1- 6alkyl and -N(C 1-6 alkyl)2; provided that, Not O. The nucleotide-lipid conjugate monomer of claim 1 or its pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer, wherein, Z 1 Z 2 Z 3 Z 4 Each is independently selected from -O-, -N(R) a -, -C(=O)-, -OC(=O)NR a -、-C(=O)NR a -、-C(=O)NR a NR a C(=O)-、-NR a C(=O)O-、-NR a C(=O)-、-NR a C(=O)NR a -、-OC 1-6 Alkylene-, -NR a C 1-6 Alkylene-, -OC(=O)NR a C 1-4 Alkylene-, -NR a C(=O)OC 1-4 Alkylene-, -NR a C(=O)C 1-4 Alkylene-,-C(=O)NR a C 1-4 Alkylene-, -NR a C(=O)NR a C 1-4 Alkylene -, -(CH2OCH2) t -、-C 1-4 Alkylene (CH2OCH2) t -、-(CH2OCH2) t C 1-4 alkylene-, -C 1-4 Alkylene (CH2OCH2) t C 1-4 Alkylene-,-C(=O)NR a -C 1-4 Alkylene-NR a -C 1-4 Alkylene-NR a C(=O)-、 C 3-6 cycloalkylene, 4-7 membered heterocyclylene, 5-6 membered heteroarylene, and any combination thereof, or, Z 1 , Z 2 , Z 3 , Z 4 1, 2, or 3 of R a and t are as defined in claim 1, Preferably, Z 1 Z 2 Z 3 Z 4 Each is independently selected from -O- and -NR. a -、-C(=O)-、-NR a C(=O)NR a -、-C(=O)NR a NR a C(=O)-、-O(CH2) m -、-OC(=O)NR a (CH2) n -、-NR a C(=O)(CH2) n -、-NR a C(=O)O(CH2) n -、-C(=O)NR a (CH2) n -、-(CH2) p (CH2OCH2) t (CH2) q -、-C(=O)NR a (CH2) m NR a (CH2) m NR a C(=O)-、 4-6 membered heterocyclylene, 5-6 membered heteroarylene, and any combination thereof, or, Z 1 , Z 2 , Z 3 , Z 4 1, 2, or 3 of R a are each independently selected from H, methyl, ethyl, and isopropyl; Preferably, Z 1 is absent or selected from -0(CH2) m -, -OC(=0)NR a -, -NR a C(=0)(CH2) n - and -NR a C(=0)0(CH2) n -, wherein m is 1, 2, 3 or 4, n is 0, 1, 2, 3 or 4, R a each independently selected from H and methyl, Preferably, Z 1 is absent or selected from -OCH2-, -OCH2CH2-, -OCH2CH2CH2-, -OC(=O)NH-, -NHC(=O)-, -NHC(=O)O-, -NHC(=O)CH2-, -NHC(=O)OCH2CH2-, and -NHC(=O)CH2CH2-; Preferably, Z 2 It does not exist, or it is selected from -C(=O)NR a (CH2) n -、-NR a C(=O)NR a -、-C(=O)NR a NR a C(=O)- and -(CH2) p (CH2OCH2) t (CH2) q - where n is 0, 1, 2, or 3, p is 0, 1, or 2, q is 0, 1, or 2, t is 1, 2, or 3, and R a Each is independently selected from H and methyl. Preferably, Z 2 is absent, or is selected from -C(=O)NH-, -C(=O)NHCH2-, -C(=O)NHNHC(=O)-, -NHC(=O)NH-, -CH2OCH2-, -CH2(CH2OCH2)2-, -(CH2OCH2)2CH2-, and -CH2(CH2OCH2)2CH2-; Preferably, Z 3 It does not exist, or is selected from 5-6-membered heteroaryl and 4-6-membered heterocyclic groups, wherein the 5-6-membered heteroaryl and 4-6-membered heterocyclic groups contain 1, 2, 3 or 4 N atoms. Preferably, Z 3 It does not exist, or is selected from pyridine, pyrazolidine, imidazolyl, triazolidine, isoxazolidine, oxazolidine, pyridinidine, pyridazinidine, pyrazinidine, zazonyl, pyridinealkyl, piperidinidine, piperazinidine, homopiperazinidine, and morpholinoyl. Preferably, Z 3 is absent or is selected from Pyridine, isoxazolyl, pyridinyl, pyrazinyl, pyridinealkyl, piperidinyl, and piperazinyl; Preferably, Z is absent, or is selected from -O-, -NR 4 absent, or is selected from -O-, -NR a -, -C(=O)-, -C(=O)NR a -, -NR a C(=O)-, and -C(=O)NR a (CH2) m NR a (CH2) m NR a C(=O)-, wherein m is 1, 2, 3 or 4, R a are each independently selected from the group consisting of H and methyl, Preferably, Z 4 It does not exist, or is selected from -O-, -NH-, -C(=O)-, -C(=O)NH-, -NHC(=O)-, The nucleotide-lipid conjugate monomer of claim 1 or 2, or its pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer, wherein, selected from the group consisting of wherein the * end is attached to R 1 . The nucleotide-lipid conjugate monomer of claim 1 or 2, or its pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer, wherein, -Z 1 -Z 2 - It does not exist, or it is a structure composed of one or more of the following groups (e.g., 1, 2, 3, 4, or 5): -O-, -N(R a )-, -C(=O)-, -OC(=O)-, -C(=O)O-, -C(=O)NR a -、-NR a C(=O)-、-OC(=O)NR a -、-NR a C(=O)O-、-C 1-6 alkylene-, R a Each is independently selected from H and methyl; Z 3 selected from 5-9 membered heteroaryl and 4-9 membered heterocyclyl; Z 4 is absent, or is selected from -O-, -NR a -, -C(=O)-, -OC(=O)-, -C(=O)O-, -C(=O)NR a - and -NR a C(=O)-; Preferably, -Z 1 -Z 2 -Does not exist, or selected from -OC 1-6 Alkylene-, -OC 1-6 Alkylene-C(=O)NR a C 1-6 Alkylene-, -NR a C(=O)C 1-6 Alkylene-, -OC(=O)NR a -、-NR a C(=O)O-、-C(=O)NR a -and-NR a C(=O)-,R a Each is independently selected from H and methyl; - Z 1 - Z 2 - is absent or is selected from -OCH2-, -OCH2-C(=O)NHCH2-, -NHC(=O)CH2-, -OC(=O)NH-, -NHC(=O)O-, and -NHC(=O)-; - Z 1 - Z 2 - is absent or is selected from -OCH2-C(=O)NHCH2-, -NHC(=O)CH2-, -OC(=O)NH-, -NHC(=O)O-, and -NHC(=O)-; Preferably, Z 3 Selected from 5-6 membered heteroaryl and 4-6 membered heterocyclic groups; Preferably, Z 3 Selected from triazolyl, pyrrolyl, isoxazolyl, pyridinyl, pyrazinyl, pyrrolylalkyl, piperidinyl, and piperazinyl; Preferably, Z is selected from -O-, -NH-, and -C(=O)-; and 4 is absent, or is selected from -O-, -NH-, and -C(=O)-; Preferably, selected from the group consisting of wherein the * end is attached to R 1 ; Preferably, selected from the group consisting of wherein the * end is attached to R 1 . The nucleotide-lipid conjugate monomer of any one of claims 1-4, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, R 1 selected from C 12-28 alkyl and C 12-28 alkenyl, said C 12-28 alkyl and C 12-28 alkenyl are optionally substituted with one or more groups selected from H, halogen, OH, CN, COOH, -OCH3, -NHCH3, and -N(CH3)2; Preferably, R 1 Selected from C 14-24 Alkyl, the C 14-24 The alkyl group may be optionally substituted with one or more groups selected from H, halogen, OH, CN, COOH, -OCH3, -NHCH3 and -N(CH3)2; Preferably, R 1 is C 15-22 alkyl; Preferably, R 1 Selected from CH2(CH2) 13 CH3, CH2(CH2) 14 CH3, CH2(CH2) 15 CH3, CH2(CH2) 16 CH3, CH2(CH2) 17 CH3, CH2(CH2) 18 CH3, CH2(CH2) 19 CH3 and CH2(CH2) 20 CH3. The nucleotide-lipid conjugate monomer of any one of claims 1-5, or its pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer, wherein, the structure shown in formula I is selected from The nucleotide-lipid conjugate monomer or its pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer according to any one of claims 1-6, wherein, The nucleotide-lipid conjugate monomer comprises a structure represented by Formula (II), in, Z 1 , Z 2 , Z 3 , Z 4 , R 1 as defined in any one of claims 1 to 6; X is either O or S; Y is O or NR b ; R b selected from H and C 1-6 alkyl; B can be a natural or non-natural base, or a modified or unmodified base. The nucleotide-lipid conjugate monomer of any one of claims 1-7, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, X is O. The nucleotide-lipid conjugate monomer of any one of claims 1-8, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, Y is O or NR b R b is selected from H and C 1-4 alkyl; Preferably, R b is selected from H, methyl, ethyl and isopropyl; Preferably, Y is O. The nucleotide-lipid conjugate monomer of any one of claims 1-9, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, B is a nucleotide base or a nucleotide base with a protecting group; Preferably, B is uracil, cytosine, adenine, guanine, uracil with an amino protecting group, cytosine with an amino protecting group, adenine with an amino protecting group, or guanine with an amino protecting group. Preferably, B is The nucleotide-lipid conjugate monomer of any one of claims 1-10, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, The structure described in formula (II) is selected from the structures shown in Table A: Table A The nucleotide-lipid conjugate monomer of any one of claims 1-11, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, The structure described in formula (II) is selected from the structures shown in Table B: Table B The nucleotide-lipid conjugate monomer or its pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer according to any one of claims 1-12, wherein, The structure of the nucleotide-lipid conjugate monomer is shown in formula (III). in, Z 1 , Z 2 , Z 3 , Z 4 , R 1 , X, Y and B are as defined in any one of claims 1 to 10; Preferably, B is R 2 , R 3 each independently is selected from H, an OH protecting group, and a reactive phosphorus group; or R 2 and R 3 with the adjacent atom to form a protecting group. The nucleotide-lipid conjugate monomer or its pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer according to any one of claims 1-13, wherein, R 2 R is OH protecting group; Preferably, R 2 Selected from trimethylsilyl (TMS), triethylsilyl (TES), dimethylisopropylsilyl (DMIPS), diethylisopropylsilyl (DEIPS), tert-butyldimethylsilyl (TBDMS), tert-butyldiphenylsilyl (TBDPS), triisopropylsilyl (TIPS), acetyl (Ac), chloroacetyl, dichloroacetyl, trichloroacetyl, trifluoroacetyl (TFA), benzoyl, p-methoxybenzoyl, 9-fluorenylmethoxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), 2,2,2-trichloroethoxycarbonyl ( Troc), benzyloxycarbonyl (Cbz), tert-butyloxycarbonyl (Boc), benzyl (Bn), p-methoxybenzyl (PMB), allyl, triphenylmethyl (Tr), bis-p-methoxytriphenylmethyl (DMTr), methoxymethyl (MOM), phenoxymethyl (BOM), 2,2,2-trichloroethoxymethyl, 2-methoxyethoxymethyl (MEM), methylthiomethyl (MTM), p-methoxybenzyloxymethyl (PMBM), -C(O)CH2CH2C(O)OH and 4,4'-dimethoxytriphenylmethyl (DMTr); Preferably, R 2 is 4,4'-dimethoxytrityl (DMTr); Or, R 2 For H; Preferably, R 3 is a reactive phosphorus group; Preferably, R 3 selected from phosphoramidites, H-phosphonates, alkyl-phosphonates, phosphates and phosphate analogs, such as natural phosphates, phosphorothioates, phosphorodithioates, boranophosphates, boranophosphorothioates, halogen substituted phosphonates and phosphates, phosphoramidates, phosphodi esters, phosphotriesters, phosphorodiesters, phosphorotriesters, diphosphates or triphosphates; Preferably, R 3 for Or, R 3 For H; Or, R 2 and R 3 It connects with adjacent atoms to form The nucleotide-lipid conjugate monomer of any one of claims 1-14, or its pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer, wherein, The structure of the nucleotide-lipid conjugate monomer is selected from the structures shown in Table C: Table C An oligonucleotide or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein the oligonucleotide comprises one or more nucleotide-lipid conjugate units or pharmaceutically acceptable salts, tautomers, enantiomers, or stereoisomers thereof, the nucleotide-lipid conjugate unit comprising the structure shown in formula (I). wherein Z 1 , Z 2 , Z 3 , Z 4 , R 1 as defined in any one of claims 1 to 6. The oligonucleotide of claim 16, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, The nucleotide-lipid conjugate unit comprises the structure shown in formula (II). in, Z 1 , Z 2 , Z 3 , Z 4 , R 1 , X, Y, B are as defined in any of claims 1 to 10. The oligonucleotide of claim 16 or 17, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, The oligonucleotide is selected from siRNA, miRNA, shRNA, nucleic acid aptamers, ribozymes, and RNA activators. Preferably, the oligonucleotide is siRNA. The oligonucleotide according to any one of claims 16-18, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, The siRNA contains an antisense strand and a sense strand; Preferably, the antisense strand and the sense strand are each 15-25 nucleotides in length independently; Preferably, the antisense strand and the sense strand are each independently 19-23 (e.g., 19, 20, 21, 22, 23) nucleotides in length. The oligonucleotide of claim 19, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, The nucleotide-lipid conjugate unit is located at one or more of the following locations (e.g., 1, 2, 3, 4, 5, or 6): -The 3' end or 5' end of the antisense chain or the justice chain; -The internal location of the antisense chain or the justice chain; Preferably, the nucleotide-lipid conjugate unit is located at the 5' end of the positive strand; Preferably, the nucleotide-lipid conjugate unit is located at the 3' end of the positive strand; Preferably, the nucleotide-lipid conjugate unit is located at positions 2-9 from the 5' end to the 3' end of the positive strand, for example, at positions 2, 3, 4, 5, 6, 7, 8, and 9 from the 5' end to the 3' end of the positive strand; more preferably, at positions 2, 3, and 6 from the 5' end to the 3' end of the positive strand. Preferably, the nucleotide-lipid conjugate unit is located at positions 2-12 from the 3' end to the 5' end of the positive strand, for example, at positions 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12 from the 3' end to the 5' end of the positive strand, and preferably at positions 3 and 10 from the 3' end to the 5' end of the positive strand. The oligonucleotide of claim 19 or 20, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, The antisense strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides of approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides similar to the nucleotide sequence shown in SEQ ID NO:2, and / or The positive strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides having approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides similar to the nucleotide sequence shown in SEQ ID NO:42; or, The antisense strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides of approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides similar to the nucleotide sequence shown in SEQ ID NO:44, and / or The positive strand comprises at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides that are approximately 4 (e.g., 0, 1, 2, 3, or 4) nucleotides similar to the nucleotide sequence shown in SEQ ID NO:43; Preferably, the sense strand has regions in at least 15 (e.g., at least 16, 17, 18, 19, 20) consecutive nucleotides that are at least 85% complementary to the antisense strand; Preferably, the siRNA comprises a blunt end and / or a protruding end of 1 to 4 nucleotides; Preferably, the siRNA contains one or two nucleotide overhangs; Preferably, the protruding end is present at the 5' end and / or 3' end of the antisense chain and / or the justice chain; Preferably, the 3' end of the antisense strand of the siRNA contains a two-nucleotide overhang. An intermediate or a pharmaceutically acceptable salt thereof, a tautomer, an enantiomer, or a stereoisomer, wherein the intermediate has a structure represented by formula (M). wherein Z 1 , Z 2 , R 2 , R 3 , X, Y, B are as defined in any one of claims 1 to 14; Preferably, R 3 is H; Or preferably, R 2 and R 3 It connects with adjacent atoms to form R M Selected from -NH2, -CN, -N3, -COOH, -C(=O)OCH3, -C(=O)OCH2CH3, The intermediate of claim 22 or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, Does not exist, or selected from Preferably, Selected from -NH2, -N3, The intermediate of claim 22 or 23, or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, wherein, The intermediate is selected from: Use of the intermediate of any one of claims 22-24 or its pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer in the preparation of the nucleotide-lipid conjugate monomer of any one of claims 1-15 or its pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer, or the oligonucleotide of any one of claims 16-21 or its pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer. Use of the nucleotide-lipid conjugate monomer of any one of claims 1-15 or its pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer in the preparation of the oligonucleotide of any one of claims 16-21 or its pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer. A pharmaceutical composition comprising the oligonucleotide of any one of claims 16-21 or a pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer thereof, and one or more pharmaceutically acceptable carriers and / or excipients. The kit comprises a nucleotide-lipid conjugate monomer as described in any one of claims 1-15 or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof, or an oligonucleotide as described in any one of claims 16-21 or a pharmaceutically acceptable salt, tautomer, enantiomer, or stereoisomer thereof. Use of the oligonucleotide of any one of claims 16-21 or a pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer thereof or the pharmaceutical composition of claim 27 in the preparation of a medicament for treating and / or preventing disease. A method for delivering oligonucleotides to extrahepatic tissues, comprising administering to a subject in need the oligonucleotide of any one of claims 16-21 or a pharmaceutically acceptable salt, tautomer, enantiomer or stereoisomer thereof or the pharmaceutical composition of claim 27; Preferably, the extrahepatic tissue is fat, the central nervous system (CNS), the eye, or muscle. A method for inhibiting the expression of a target gene in a cell, comprising contacting the cell with an effective amount of the oligonucleotide of any one of claims 16-21 or a pharmaceutically acceptable salt thereof, tautomer, enantiomer or stereoisomer, or the pharmaceutical composition of claim 27; Preferably, the cells are cells from extrahepatic tissue; Preferably, the extrahepatic tissue is fat, the central nervous system (CNS), the eye, the lungs, or muscle; Preferably, the target genes are selected from ACVR2A, ACVR2B, ACVR1C, MSTN, PLIN1, TRARG1, CIDEA FABP4, GNG11, CTGF, RAGE, MMP, Mu5ae, SOD1, GFAP, PLP1, APP, MAPT, LRRK2, SNCA, mHTT, ATXN3, ATXN2, TTR, FUS, C9ORF72, PRNP, and MECP.

Images