Intermediates for the synthesis of 3d-mpl, processes for their preparation and use thereof

Abstract

The present application relates to the technical field of pharmaceutical chemistry, and in particular to an intermediate for synthesizing 3D-MPL, a preparation method and application thereof. A first intermediate for synthesizing 3D-MPL is selected from the compounds shown in the following structural formula: wherein n1 and n2 are respectively selected from any integer between 8 and 12. The protecting group in the intermediate can be removed efficiently and conveniently, significantly shortening the route for synthesizing 3D-MPL and significantly improving the total yield.

Description

Technical Field

[0001] This invention relates to the field of medicinal chemistry, and more specifically, to intermediates for the synthesis of 3D-MPL, their preparation methods, and their applications. Background Technology

[0002] Immunoadjuvants are a class of molecules that primarily alter cytokine levels to enhance vaccine efficacy, generally through various mechanisms such as activating MHC molecules, co-stimulatory factors, or related intracellular signaling molecules. A typical example is lipopolysaccharide (LPS), an endotoxin found in the cell walls of Gram-negative bacteria. LPS-mediated immune activation occurs through its interaction with TLR4 (toll-like receptors) and acceptor proteins MyD88 and TRIF, producing inflammatory factors such as Th1 interferon and chemokines. The most frequently evaluated family of molecules is monophosphoryl lipid A (MPL). Lipid A is an amphiphilic derivative of attenuated LPS, retaining good immunogenicity and exhibiting a similar mechanism of action to LPS. Compared to LPS, MPL exhibits significantly reduced toxicity (between 0.1% and 1%) and has proven remarkably effective. Therefore, it is widely used as an adjuvant in vaccines, allergy medications, and immunotherapies to enhance immune responses. Generally, while live attenuated vaccines have strong immunogenicity, they also have high toxicity; while inactivated vaccines, which are non-toxic, have weaker immunogenicity. The addition of adjuvants can enhance the immunogenicity of inactivated vaccines without introducing pathogenic risks. MPL is the first novel human adjuvant substance approved by the FDA, besides aluminum salts. Naturally extracted MPL sources mainly include Salmonella Minnesota extract, with 3D-MPL as the main component; and E. coli extract, EcML, with MPL-12 as the main component, both of which are in clinical trials. Several new vaccines using the MPL adjuvant system have already been marketed domestically and internationally, such as the hepatitis B vaccine Fendrix, the cervical cancer vaccine Cerivix, the shingles vaccine Shingrix, and the malaria vaccine Mosquirix.

[0003] Most existing MPL sources are bio-extracted. However, MPL derived from different bacteria or different serotypes of the same bacteria has different structures, primarily differing in the number and linkage positions of fatty acid chains and the length of their carbon chains. Bio-extracted MPL is mostly a mixture, with significant fluctuations in mixing ratios, resulting in highly unstable quality and posing substantial safety risks when used as an adjuvant. Furthermore, compared to naturally extracted MPL, synthetically produced MPL induces higher levels of cytokines in immunized mice, with comparable induction levels for CD4+ T cells and CD8+ T cells. However, synthetic MPL can also induce and activate NKT cells. MPL synthesis is currently a hot topic, with several methods, including GLA (MPLA) and 3D-MPL, already in preclinical evaluation. However, these methods are structurally complex, involve long synthesis routes, and present the following challenges:

[0004] 1. Ligands that typically provide the phosphate group are benzyl pyrophosphate (di-O-benzyloxy(N,N-diisopropylamino)phosphine) or o-xylene-N,N-diethylphosphamide as the source of the phosphate group, with Bn as the protecting group. All of these protecting groups must ultimately be removed under hydrogenation conditions, and the purification process is complex and difficult to scale up for production.

[0005] 2. The reported synthetic routes for the total synthesis of MPL analogs are all quite long. In addition to the fact that the benzyl protecting group used is difficult to completely remove during the later deprotection process, some temporary protecting groups are usually required to avoid side reactions in the reaction. This results in the involvement of multiple protecting groups, requiring repeated protection and deprotection, which leads to lengthy routes, poor selectivity, low yield, and many impurities.

[0006] To address these issues, the inventors have developed a highly effective MPLA synthesis process. Considering that 3D-MPL has a more stable chemical structure than MPLA, and that preclinical experiments have shown it to be superior to MPLA in anti-inflammatory and antiviral effects, as well as significantly increasing IgG antibody titers in immunized mice, we have further developed a scalable 3D-MPL synthesis method. Based on this, we propose this invention.

[0007] The 3D-MPL structure is shown below;

[0008] In the formula, n1~n6 are independent integers between 8 and 12. Preferably, n1, n3 and n5 are independently 10, 12 and 14, and n2, n4 and n6 are independently 8, 10 or 12. Summary of the Invention

[0009] The purpose of this invention is to provide intermediates for the synthesis of 3D-MPL, their preparation methods, and their applications. Embodiments of this invention provide a series of novel intermediates for the synthesis of 3D-MPL, in which the protecting groups can be efficiently and conveniently removed, significantly shortening the synthetic route for 3D-MPL and significantly improving the overall yield.

[0010] This invention is implemented as follows:

[0011] In a first aspect, the present invention provides a first intermediate (hereinafter also referred to as compound 5) for the synthesis of 3D-MPL, the first intermediate being selected from compounds with the following structural formulas:

[0012] , where n1 and n2 are selected from any integers between 8 and 12.

[0013] Secondly, the present invention provides a method for preparing the first intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, comprising synthesizing according to the following synthetic route:

[0014] , where n1 and n2 are selected from any integers between 8 and 12.

[0015] Thirdly, the present invention provides a second intermediate (hereinafter also referred to as compound 6) for the synthesis of 3D-MPL, the second intermediate being selected from compounds shown in the following structural formulas:

[0016] , where n1 and n2 are selected from any integers between 8 and 12.

[0017] Fourthly, the present invention provides a method for preparing the second intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, comprising: glycosylation reaction of the first intermediate described in the foregoing embodiments with compound B in an organic solvent in the presence of an acid catalyst to obtain the second intermediate; the specific synthetic route is as follows:

[0018]

[0019] , where n1 and n2 are selected from any integers between 8 and 12.

[0020] Fifthly, the present invention provides a third intermediate (hereinafter also referred to as compound 7) for the synthesis of 3D-MPL, said third intermediate being selected from compounds with the following structural formulas:

[0021] , where n1 and n2 are selected from any integers between 8 and 12.

[0022] Sixthly, the present invention provides a method for preparing the third intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, comprising: in an organic solvent, under zinc powder / acid catalysis, performing a deprotection reaction of the Troc protecting group at the 2-position of the second intermediate described in the foregoing embodiments to obtain the third intermediate, the specific synthetic route of which is as follows:

[0023]

[0024] , where n1 and n2 are selected from any integers between 8 and 12.

[0025] In a seventh aspect, the present invention provides a fourth intermediate (hereinafter also referred to as compound 8) for the synthesis of 3D-MPL, said fourth intermediate being selected from compounds with the following structural formulas:

[0026] , where n1 and n2 are selected from any integers between 8 and 12.

[0027] Eighthly, the present invention provides a method for preparing a fourth intermediate for the synthesis of 3D-MPL as described in the foregoing embodiments. In an organic solvent, under condensing agent catalysis, the third intermediate described in the foregoing embodiments is subjected to an amidation condensation reaction with compound C to obtain the fourth intermediate. The specific synthetic route is as follows:

[0028]

[0029] , where n1 and n2 are selected from any integers between 8 and 12.

[0030] In a ninth aspect, the present invention provides a fifth intermediate (hereinafter also referred to as compound 9) for the synthesis of 3D-MPL, said fifth intermediate being selected from compounds with the following structural formulas:

[0031] , where n1 and n2 are selected from any integers between 8 and 12.

[0032] In a tenth aspect, the present invention provides a method for preparing a fifth intermediate for the synthesis of 3D-MPL as described in the foregoing embodiments, comprising: in an organic solvent, under desilylation catalysis, subjecting the fourth intermediate described in the foregoing embodiments to a silyl ether protecting group removal reaction to obtain the fifth intermediate; the specific synthetic route is as follows:

[0033]

[0034] , where n1 and n2 are selected from any integers between 8 and 12.

[0035] In one aspect, the present invention provides a sixth intermediate (hereinafter also referred to as compound 10) for the synthesis of 3D-MPL, said sixth intermediate being selected from compounds with the following structural formulas:

[0036] , where n1 to n6 are selected from any integers between 8 and 12.

[0037] In a twelfth aspect, the present invention provides a method for preparing a sixth intermediate for the synthesis of 3D-MPL as described in the foregoing embodiments, comprising: in an organic solvent, under palladium catalysis, performing an allyloxy protecting group removal reaction on the fifth intermediate described in the foregoing embodiments to obtain the sixth intermediate; the specific synthetic route is as follows:

[0038]

[0039] , where n1 to n6 are selected from any integers between 8 and 12.

[0040] In a thirteenth aspect, the present invention provides a method for preparing 3D-MPL, comprising: preparing 3D-MPL using any one of the following: a first intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a second intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a third intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a fourth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a fifth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, or a sixth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments.

[0041] In a fourteenth aspect, the present invention provides the use of a first intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a second intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a third intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a fourth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a fifth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, or a sixth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments in the preparation of the immune adjuvant 3D-MPL.

[0042] The present invention has the following beneficial effects: Among the series of intermediates (compounds 5 to 10) provided in the embodiments of the present invention, compound 5 uses allyl oxycarbonyl (Alloc) to selectively protect the 3-position and naphthylmethyl (Nap) as the 4-position protecting group; compound 6 selects naphthylmethyl (Nap), allyl (Allyl), allyl oxycarbonyl (Alloc) silyl ether (TBS) as protecting groups; compounds 7, 8, 9 and 10 use allyl phosphate ligands as the source of phosphate groups in 3D-MPL and Nap as the protecting group, which can be easily removed in subsequent operations; the above-mentioned intermediate synthesis routes are short and the overall yield is significantly increased, providing a basis for the synthesis and scale-up of 3D-MPL. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 The 1H NMR spectrum of compound 5 is provided for Example 7 of this invention;

[0045] Figure 2 A mass spectrum of compound 5 is provided for Example 7 of the present invention;

[0046] Figure 3 The 1H NMR spectrum of compound 6 is provided for Example 8 of this invention;

[0047] Figure 4 The carbon NMR spectrum of compound 6 is provided for Example 8 of this invention;

[0048] Figure 5 A mass spectrum of compound 6 is provided for Example 8 of the present invention;

[0049] Figure 6 The 1H NMR spectrum of compound 7 is provided for Example 9 of this invention;

[0050] Figure 7 The carbon NMR spectrum of compound 7 is provided for Example 9 of this invention;

[0051] Figure 8 A mass spectrum of compound 7 is provided for Example 9 of the present invention;

[0052] Figure 9 The 1H NMR spectrum of compound 8 is provided for Example 10 of the present invention;

[0053] Figure 10 The carbon NMR spectrum of compound 8 is provided for Example 10 of the present invention;

[0054] Figure 11 A mass spectrum of compound 8 is provided for Example 10 of the present invention;

[0055] Figure 12 The 1H NMR spectrum of compound 9 is provided for Example 11 of this invention;

[0056] Figure 13 The carbon NMR spectrum of compound 9 is provided for Example 11 of this invention;

[0057] Figure 14 A mass spectrum of compound 9 is provided for Example 11 of the present invention;

[0058] Figure 15 The 1H NMR spectrum of compound 10 is provided for Example 12 of the present invention;

[0059] Figure 16 The carbon NMR spectrum of compound 10 is provided for Example 12 of the present invention;

[0060] Figure 17 A mass spectrum of compound 10 is provided for Example 12 of the present invention. Detailed Implementation

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0062] In a first aspect, the present invention provides a first intermediate (hereinafter also referred to as compound 5) for the synthesis of 3D-MPL, the first intermediate being selected from compounds with the following structural formulas:

[0063] Where n1 and n2 are selected from any integers between 8 and 12, preferably n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0064] Specifically, compound 5 is selected from any one of the compounds shown in the following structural formulas:

[0065] .

[0066] This invention specifically employs TBS and Alloc as protecting groups, which not only ensures the formation of subsequent intermediates and the synthesis of 3D-MPL, but also guarantees a high yield. The inventors discovered that changing the protecting groups, such as replacing Alloc with trichloroacetonitrile, Nap, benzyl, or TBS, may prevent subsequent reactions from proceeding, resulting in low yields or even the failure to form 3D-MPL.

[0067] Secondly, the present invention provides a method for preparing the first intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, comprising:

[0068] (1) Synthesize compound 2;

[0069] In an organic solvent, in the presence of an acid-binding agent, compound 1 is reacted with allyl chloroformate to obtain compound 2; the specific synthetic route is as follows:

[0070] .

[0071] The organic solvent is a haloalkane solvent, preferably dichloromethane and / or trichloromethane; the mass-to-volume ratio of compound 1 to the organic solvent is 50-200 g / L, preferably 100 g / L. The acid-binding agent is pyridine, triethylamine, or tetramethylethylenediamine (TMEDA), preferably TMEDA. The molar ratio of the acid-binding agent to compound 1 is 1-3:1, preferably 1-2:1. The molar ratio of allyl chloroformate to compound 1 is 2-5:1, preferably 3-4:1. The reaction temperature is 0-30℃, preferably 10-20℃. The reaction process is monitored, and the reaction endpoint is defined as the disappearance of compound 1 or the cessation of its decrease; preferably, the reaction time is 1-5 h.

[0072] The reaction also includes the following post-processing steps: after the reaction is completed, quenching, washing, drying, filtering, concentration, and separation and purification are performed; for example, washing is performed sequentially with saturated sodium bicarbonate solution and saturated sodium chloride solution; separation and purification are performed by column chromatography, with silica gel as the packing material and petroleum ether and ethyl acetate as the eluent.

[0073] It should be noted that the protecting group in compound 2 can only be one of the three protecting groups mentioned above, and its position cannot be changed. Changing any of the three protecting groups may prevent subsequent reactions from proceeding. For example, when compound 6 forms compound 7, it may not only remove Troc from the NH4+, but also remove TBS or Alloc. If Alloc is replaced with another protecting group, the protecting group at the Alloc position may also be removed when TBS is removed, causing the reaction to fail or the yield to decrease significantly.

[0074] (2) Synthesize compound 3;

[0075] In an organic solvent, compound 2 is reduced in the presence of acetic acid and zinc powder to obtain compound 3; the specific synthetic route is as follows:

[0076] .

[0077] The organic solvent is a haloalkane solvent, preferably dichloromethane and / or trichloromethane; the mass-to-volume ratio of compound 2 to the organic solvent is 50-200 g / L, preferably 100 g / L; the mass ratio of acetic acid to compound 2 is 2-5:1, preferably 3.5:1. The mass ratio of zinc powder to compound 2 is 1-3:1, preferably 2:1. The reaction temperature is 0-30℃, preferably 10-20℃. The reaction process is monitored, and the reaction endpoint is defined as the disappearance of compound 2 or the cessation of its decrease; preferably, the reaction time is 3-6 hours.

[0078] The operation steps also include the following post-processing steps after the reaction: after the reaction, filtration, washing, drying, concentration, separation and purification; for example, the washing is carried out sequentially with saturated sodium bicarbonate solution and saturated sodium chloride solution; the separation and purification is carried out by column chromatography, with silica gel as the packing material and petroleum ether and ethyl acetate as the eluent.

[0079] (3) Synthesize compound 4;

[0080] In an organic solvent, in the presence of triethylsilane (Et3SiH) and dichlorophenylborane (PhBCl2), compound 3 underwent a selective reduction ring-opening reaction to yield compound 4; the specific synthetic route is as follows:

[0081] .

[0082] The organic solvent is a haloalkane solvent, preferably dichloromethane and / or trichloromethane; the mass-volume ratio of compound 3 to the organic solvent is 50~200 g / L; the molar ratio of Et3SiH to compound 3 is 2~5:1, preferably 3:1; the molar ratio of PhBCl2 to compound 3 is 2~5:1, preferably 3:1; the reaction temperature is -90~40℃, preferably -78℃; the reaction process is monitored, and the reaction endpoint is defined as when compound 3 disappears or its content no longer decreases; preferably, the reaction time is 0.5-2h.

[0083] The process also includes the following post-processing steps after the reaction: After the reaction, the reaction product is sequentially quenched, filtered, washed, dried, concentrated, and purified. For example, quenching is performed using pyridine or triethylamine; washing can be performed sequentially using saturated sodium bicarbonate solution and saturated sodium chloride solution; purification is achieved by column chromatography, using silica gel as the packing material and petroleum ether and ethyl acetate as the eluent.

[0084] (4) Synthesize compound 5;

[0085] In an organic solvent, in the presence of a condensing agent, compound 4 is subjected to an acylation reaction with compound A as shown below to give compound 5, the first intermediate; the synthesis is carried out according to the following synthetic route:

[0086] In the formula, n1 and n2 are any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0087] The organic solvent is a haloalkane solvent, preferably dichloromethane and / or trichloromethane; the condensing agent is one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl), dicyclohexylcarbodiimide (DCC), and N,N'-diisopropylcarbodiimide (DIC), preferably 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; the mass-volume ratio of compound 4 to organic solvent is 50~200 g / L; the molar ratio of condensing agent to compound 4 is 1~5:1, preferably 1~3:1; the molar ratio of compound A to compound 4 is 1~3:1, preferably 1~2.5:1; the reaction temperature is -10~50℃, more preferably 10~30℃; the reaction process is monitored, and the reaction endpoint is defined as when compound 4 disappears or its content no longer decreases; preferably, the reaction time is 2~12 h.

[0088] The procedure also includes the following post-processing steps after the acylation reaction: washing, drying, filtering, concentration, and purification of the target product are performed sequentially. For example, washing involves sequential washing with saturated sodium bicarbonate solution and saturated sodium chloride solution; purification is performed by column chromatography using silica gel as the packing material and petroleum ether and ethyl acetate as the eluent.

[0089] Thirdly, the present invention provides a second intermediate (hereinafter also referred to as compound 6) for the synthesis of 3D-MPL, the second intermediate being selected from compounds shown in the following structural formulas:

[0090] Wherein, n1 and n2 are selected from any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0091] For example, compounds with any of the following specific structures:

[0092] .

[0093] Fourthly, the present invention provides a method for preparing the second intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, comprising: glycosylation reaction of the first intermediate described in the foregoing embodiments with compound B in an organic solvent in the presence of an acid catalyst to obtain the second intermediate; the specific synthetic route is as follows:

[0094]

[0095] In the formula, n1 and n2 are any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0096] The organic solvent is a haloalkane solvent, more preferably dichloromethane and / or trichloromethane; the mass-volume ratio of compound 5 to the organic solvent is 50~200 g / L; the acid catalyst is one or more of trifluoromethanesulfonic acid (TfOH), trimethylsilyl trifluoromethanesulfonate (TMSOTf), and trifluoromethanesulfonic anhydride (Tf2O); preferably trifluoromethanesulfonic acid (TfOH); the molar ratio of acid catalyst to compound 5 is 3~5:1, preferably 4~5:1; the molar ratio of compound B to compound 5 is 5:8~10, preferably 5:8; the reaction temperature is -10℃~-40℃, preferably -20℃; the reaction process is monitored, and the reaction endpoint is defined as when compound 5 disappears or its content no longer decreases, preferably 2h-12h, more preferably 2-6h.

[0097] The preparation method also includes the following post-processing steps: after the reaction is completed, the reaction system is sequentially quenched, concentrated, and purified. The quenching reagent is selected from pyridine, and the separation and purification are preferably carried out by column chromatography. The packing material for column chromatography is C18 or silica gel, and the eluent for column chromatography is petroleum ether and ethyl acetate.

[0098] Fifthly, the present invention provides a third intermediate (hereinafter also referred to as compound 7) for the synthesis of 3D-MPL, said third intermediate being selected from compounds with the following structural formulas:

[0099] Wherein, n1 and n2 are selected from any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0100] For example, a compound with any of the following specific structures:

[0101] .

[0102] Sixthly, the present invention provides a method for preparing the third intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, comprising: in an organic solvent, under zinc powder / acid catalysis, performing a deprotection reaction of the Troc protecting group at the 2-position of the second intermediate described in the foregoing embodiments to obtain the third intermediate, the specific synthetic route of which is as follows:

[0103]

[0104] Wherein, n1 and n2 are selected from any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0105] The organic solvent is a haloalkane solvent, more preferably dichloromethane and / or trichloromethane; the mass-volume ratio of compound 6 to the organic solvent is 50~200 g / L; the acid can be one or more of acetic acid, hydrochloric acid, and sulfuric acid, more preferably acetic acid; the mass-volume ratio of acid to compound 6 is 1~5 g / mL, more preferably 3 g / mL; the molar ratio of zinc powder metal catalyst to compound 6 is 20~15:1, more preferably 16:1; the reaction temperature is 10℃~30℃, more preferably room temperature; the reaction process is monitored, and the reaction endpoint is when compound 6 disappears or its content no longer decreases; preferably, the reaction time is 2h-6h.

[0106] The preparation method further includes the following post-processing steps: after the reaction is completed, the reaction system is washed and purified. For example, washing is performed sequentially with water, saturated sodium bicarbonate solution, and saturated sodium chloride solution; purification is performed by column chromatography; the packing material for column chromatography is silica gel, and the eluent is petroleum ether and ethyl acetate.

[0107] In a seventh aspect, the present invention provides a fourth intermediate (hereinafter also referred to as compound 8) for the synthesis of 3D-MPL, said fourth intermediate being selected from compounds with the following structural formulas:

[0108] Wherein, n1 and n2 are selected from any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0109] For example, a compound with any of the following specific structures:

[0110] .

[0111] Eighthly, the present invention provides a method for preparing a fourth intermediate for the synthesis of 3D-MPL as described in the foregoing embodiments. In an organic solvent, under condensing agent catalysis, the third intermediate described in the foregoing embodiments is subjected to an amidation condensation reaction with compound C to obtain the fourth intermediate. The specific synthetic route is as follows:

[0112]

[0113] Wherein, n1 and n2 are selected from any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0114] The organic solvent is a haloalkane solvent, more preferably dichloromethane and / or trichloromethane; the mass-to-volume ratio of compound 7 to the organic solvent is 120~200 g / L; the condensing agent is one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCl), dicyclohexylcarbodiimide (DCC), and N,N'-diisopropylcarbodiimide (DIC); preferably 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; the molar ratio of the condensing agent to compound 7 is 5~10:1, more preferably 6:1; the molar ratio of compound C to compound 7 is 5~10:1, more preferably 6:1; the reaction temperature is 10℃~30℃, more preferably room temperature; the reaction progress is monitored, and the reaction endpoint is when compound 7 disappears or its content no longer decreases; preferably, the reaction time is 2h-6h.

[0115] The preparation method further includes the following post-processing steps: after the reaction is complete, washing, rotary evaporation, and separation and purification. For example, the washing is performed with a saturated sodium chloride solution; the separation and purification is performed by: after rotary evaporation, purification through a C18 packing material, eluting with acetonitrile, methanol, and chloroform sequentially, followed by purification by silica gel column chromatography using petroleum ether and ethyl acetate as eluents.

[0116] In a ninth aspect, the present invention provides a fifth intermediate (hereinafter also referred to as compound 9) for the synthesis of 3D-MPL, said fifth intermediate being selected from compounds with the following structural formulas:

[0117] Wherein, n1 and n2 are selected from any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0118] For example, a compound with any of the following specific structures:

[0119] .

[0120] In a tenth aspect, the present invention provides a method for preparing a fifth intermediate for the synthesis of 3D-MPL as described in the foregoing embodiments, comprising: in an organic solvent, under desilylation catalysis, subjecting the fourth intermediate described in the foregoing embodiments to a silyl ether protecting group removal reaction to obtain the fifth intermediate; the specific synthetic route is as follows:

[0121]

[0122] Wherein, n1 and n2 are selected from any integers between 8 and 12. Preferably, n1 is 10, 12 or 14, and n2 is 8, 10 or 12.

[0123] The organic solvent is a furan solvent, preferably tetrahydrofuran; the mass-to-volume ratio of compound 8 to the organic solvent can be 30-40 g / L; the desilication catalyst is HF / Py, wherein the mass fraction of Py is 65-70%; the mass-to-volume ratio of the desilication catalyst to compound 8 is 50-150 g / L, preferably 100 g / L; the reaction temperature can be 10℃-30℃, preferably room temperature; the reaction process is monitored, and the reaction endpoint is reached when compound 8 disappears or its content no longer decreases; preferably, the reaction time is 8-16 h, more preferably 8-12 h.

[0124] The preparation method further includes the following post-processing steps: after the reaction is completed, quenching, extraction, concentration, and purification are performed. For example, quenching is achieved by adding a saturated sodium bicarbonate aqueous solution for neutralization, extraction is performed using chloroform, concentration is achieved by concentrating the organic solvent to constant weight using a rotary evaporator, and purification is achieved by C18 packed-pack chromatography, using acetonitrile, methanol, and chloroform as eluents to obtain the target product.

[0125] In one aspect, the present invention provides a sixth intermediate (hereinafter also referred to as compound 10) for the synthesis of 3D-MPL, said sixth intermediate being selected from compounds with the following structural formulas:

[0126] Where n1 to n6 are selected from any integers between 8 and 12, preferably n1, n3 and n5 are independently 10, 12 and 14, and n2, n4 and n6 are independently 8, 10 or 12.

[0127] For example, a compound with any of the following specific structures:

[0128] .

[0129] In a twelfth aspect, the present invention provides a method for preparing a sixth intermediate for the synthesis of 3D-MPL as described in the foregoing embodiments, comprising: in an organic solvent, under palladium catalysis, performing an allyloxy protecting group removal reaction on the fifth intermediate described in the foregoing embodiments to obtain the sixth intermediate; the specific synthetic route is as follows:

[0130]

[0131] Where n1 to n6 are selected from any integers between 8 and 12, preferably n1, n3 and n5 are independently 10, 12 and 14, and n2, n4 and n6 are independently 8, 10 or 12.

[0132] The organic solvent is a furan solvent, preferably tetrahydrofuran; the mass-to-volume ratio of compound 9 to the organic solvent is 30-40 g / L; the palladium catalyst is any one of tetratriphenylphosphine palladium, palladium acetate, and palladium carbonate; preferably tetratriphenylphosphine palladium.

[0133] The molar ratio of palladium catalyst to compound 9 is 7:3-5, preferably 7:4; the reaction temperature is 10℃~30℃, preferably room temperature; the reaction process is monitored, and the reaction endpoint is reached when compound 9 disappears or its content no longer decreases; preferably, the reaction time is 2-6 hours, more preferably 2-4 hours.

[0134] The preparation method further includes the following post-processing steps: after the reaction is completed, filtration, concentration, and purification are performed. For example, filtration is used to remove insoluble matter, concentration is used to concentrate to constant weight using a rotary evaporator, and purification is used to purify by C18 packed-pack chromatography, eluting with acetonitrile, methanol, and chloroform sequentially to obtain the target product.

[0135] In a thirteenth aspect, the present invention provides a method for preparing 3D-MPL, comprising: preparing 3D-MPL using any one of the following: a first intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a second intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a third intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a fourth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a fifth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, or a sixth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments.

[0136] For example, 3D-MPL can be formed using compound 10 following the synthetic pathway:

[0137]

[0138] Where n1 to n6 are selected from any integers between 8 and 12, preferably n1, n3 and n5 are independently 10, 12 and 14, and n2, n4 and n6 are independently 8, 10 or 12.

[0139] In a fourteenth aspect, the present invention provides the use of a first intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a second intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a third intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a fourth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, a fifth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments, or a sixth intermediate for synthesizing 3D-MPL as described in the foregoing embodiments in the preparation of the immune adjuvant 3D-MPL.

[0140] In summary, in this embodiment of the invention, compound 5 is prepared by amide condensation of compound 4 and compound A; then, compound 5 is glycosylated with compound B (the synthesis of compound B is described in Chinese patent application CN202010306826.6) to efficiently prepare a new compound 6; then, the Troc protecting group is removed by acid to obtain a new compound 7; similarly, it is amide condensed with a dialiphatic chain compound C (prepared in the same way as compound B) to obtain a new compound 8; compound 8 is desilylated (TBS) in HF / Py solvent to obtain compound 9; compound 9 is simultaneously deallylated (Allyl) and allyloxycarbonyl (Alloc) under Pd catalyst conditions to obtain compound 10; finally, two naphthyl Nap groups are removed under DDQ conditions to obtain 3D-MPL. Novel compound 5 uses allyloxycarbonyl (Alloc) to selectively protect the 3-position and naphthylmethyl (Nap) as the 4-position protecting group; novel compound 6 uses naphthylmethyl (Nap), allyl (Allyl), allyloxycarbonyl (Alloc), and silyl ether (TBS) as protecting groups; novel compounds 7, 8, 9, and 10 use allyl phosphate ligands as the source of phosphate groups in 3D-MPL and Nap as the protecting group, which can be easily removed in subsequent operations. The synthetic intermediate route is short and the overall yield is significantly increased, providing a basis for the synthesis and scale-up of 3D-MPL.

[0141] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0142] Example 1

[0143] This embodiment provides a method for preparing compound 1, referring to the following synthetic route:

[0144] The details are as follows:

[0145] (1) Adding 2-deoxy-1-oxo-(1,1-dimethylethyl)dimethylsilyl-2-[(2,2,2-trichloroethoxy)carbonyl]amino-3,4,6-triacetyl- β Guanidin hydrochloride buffer solution (100 mL, pH=8) was slowly added to the reaction flask containing 10 g of D-glucose (16.8 mmol) and stirred at room temperature for 3.5 h.

[0146] (2) After the raw materials were consumed by TLC detection, the reaction solution was neutralized with cation exchange resin, filtered and concentrated, and the product was extracted with dichloromethane and saturated sodium bicarbonate solution. The organic layer was collected and concentrated to obtain 2-deoxy-1-oxo-(1,1-dimethylethyl)dimethylsilyl-2-[(2,2,2-trichloroethoxy)carbonyl]amino- β -D-glucose (1-1, 8.23g).

[0147] (3) In a reaction flask, 1-1 and 2-(dimethoxymethyl)-naphthalene (5.1 g, 25 mmol, 1.5 eq) were dissolved in 50 mL of acetonitrile, and camphor sulfonic acid (0.39 g, 1.69 mmol, 0.1 eq) was added. The mixture was stirred at room temperature for 4 h, and triethylamine was added until neutral. The reaction solution was extracted with dichloromethane and saturated sodium bicarbonate solution, and the mixture was separated. The organic phase was dried by rotary evaporation to obtain a yellow solid. The crude product was passed through a silica gel sintered glass funnel (PE:EA = 5:1) to obtain compound 1 (light yellow solid, 6.97 g), with a two-step yield of 68.3%.

[0148] TOF-MS: m / z: 607.89 [M+H] + .

[0149] Compound 1: 1 H NMR (400 MHz, CDCl3) δ 7.96 – 7.50 (m, 7H), 5.72 (s, 1H), 5.17 (d, J = 6.3 Hz, 1H), 4.88 (d, J = 7.7 Hz, 1H), 4.73 (q, J = 12.0 Hz, 2H), 4.36(dd, J = 10.5, 5.0 Hz, 1H), 4.13 – 4.01 (m, 1H), 3.86 (t, J = 10.3 Hz, 1H), 3.70– 3.58 (m, 1H), 3.52 (td, J= 9.7, 5.0 Hz, 1H), 3.47 – 3.35 (m, 1H), 2.96 (s,1H), 0.94 (d, J = 8.2 Hz, 9H), 0.20 – 0.08 (m, 6H).

[0150] 13 C NMR (101 MHz, CDCl3) δ 154.54, 134.52, 133.78, 132.87, 128.41,128.29, 127.75, 126.69, 126.41, 126.07, 123.93, 101.97, 96.33, 95.30, 81.52,74.85, 70.71, 68.68, 66.20, 60.73, 26.94, 25.59, 17.90, -4.14, -5.26.

[0151] Example 2

[0152] This embodiment provides a method for preparing compound 2, referring to the following synthetic route:

[0153]

[0154] Compound 1 (10 g, 16.47 mmol) was dissolved in 100 ml of dichloromethane, TMEDA (3 g, 25.82 mmol) was added, and allyl chloroformate (6 g, 49.78 mmol) was added under ice bath conditions. After stirring at room temperature for 2 hours, compound 1 was completely consumed.

[0155] The reaction solution was quenched in ice water (100 ml), and the solution was separated. The reaction solution was then washed and separated in sequence with saturated sodium bicarbonate solution (100 ml) and saturated saline solution (100 ml).

[0156] Compound 2 was purified by rotary evaporation and silica gel column chromatography (petroleum ether: ethyl acetate = 10:1) to give compound 2 (11.3 g, 90%, colorless oily liquid).

[0157] TOF-MS: m / z: 714.13 [M+Na] + .

[0158] Compound 2: 1 H NMR (400 MHz, CDCl3) δ 7.99 – 7.44 (m, 7H), 5.95 – 5.80 (m,1H), 5.67 (s, 1H), 5.52 – 5.36 (m, 1H), 5.30 (d, J= 2.7 Hz, 2H), 5.26 – 5.16(m, 2H), 4.79 (dd, J = 16.3, 9.9 Hz, 2H), 4.32 (dd, J = 10.5, 5.0 Hz, 1H), 3.82(dt, J = 13.6, 9.9 Hz, 2H), 3.69 (dd, J = 18.3, 9.4 Hz, 1H), 3.54 (td, J = 9.7, 5.0Hz, 1H), 0.87 (s, 9H), 0.09 – -0.02 (m, 6H).

[0159] 13 C NMR (151 MHz, CDCl3) δ 134.89 – 132.26 (m), 128.64 – 127.09 (m), 126.30 – 125.10 (m), 123.49 (s), 118.41 (s), 101.44 (s), 96.52 (s), 78.96(s), 75.29(s), 74.40(s), 68.53(d, J = 17.1 Hz), 65.91 (s), 58.34 (s), 25.16 (s), -5.26 (d, J = 162.0 Hz).

[0160] Example 3

[0161] This embodiment provides a method for preparing compound 3, referring to the following synthetic route:

[0162]

[0163] Compound 2 (11 g, 15.92 mmol) was dissolved in 110 ml of dichloromethane, zinc powder (22 g, 0.336 mol) was added, and acetic acid (33 ml, 3 vol) was added under ice bath conditions. After stirring at room temperature for 3 hours, compound 2 was completely consumed.

[0164] The reaction solution was washed and separated sequentially with water (100 ml), saturated sodium bicarbonate solution (100 ml), and saturated saline solution (100 ml). The solution was purified by rotary evaporation and silica gel column chromatography (petroleum ether: ethyl acetate = 8:1) to give compound 3 (8 g, 97%, colorless oily liquid).

[0165] TOF-MS: m / z: 538.22 [M+Na]+ .

[0166] Compound 3: 1 H NMR (400 MHz, CDCl3) δ 7.95 (s, 1H), 7.90 – 7.80 (m, 3H), 7.53 (ddt, J = 8.6, 6.8, 3.1 Hz, 3H), 5.93 (ddt, J = 16.2, 10.5, 5.7 Hz, 1H), 5.68 (s, 1H), 5.45 – 5.28 (m, 1H), 5.21 (dt, J = 7.1, 3.6 Hz, 1H), 5.08 – 4.88(m, 1H), 4.76 – 4.55 (m, 3H), 4.44 – 4.28 (m, 1H), 3.84 (dt, J = 18.9, 9.8 Hz, 2H), 3.60 (td, J = 9.8, 5.0 Hz, 1H), 2.96 (dd, J = 10.0, 7.6 Hz, 1H), 0.96 (s, 9H), 0.18 (s, 6H).

[0167] 13 C NMR (151 MHz, CDCl3) δ 134.30 – 132.50 (m), 131.07 (s), 128.24 –127.27 (m), 125.81 (dd, J = 91.4, 25.4 Hz), 123.51 (s), 118.57 (s), 100.31 (d, J = 362.4 Hz), 79.17 (s), 77.54 (s), 68.57 (d, J = 26.0 Hz), 66.33 (s), 58.30(s), 25.33 (s), -5.04 (d, J = 153.6 Hz).

[0168] Example 4

[0169] This embodiment provides a method for preparing compound 4 (starting compound), referring to the following synthetic route:

[0170]

[0171] Compound 3 (4.3 g, 8.34 mmol) was dissolved in 86 ml of dichloromethane and cooled to -75 °C. Triethylsilane (4.85 g, 25.02 mmol) and dichlorophenylborane (3.3 g, 20.85 mmol) were added sequentially. After stirring at -75 °C for 1 hour, compound 3 was completely consumed.

[0172] The reaction solution was quenched with methanol (12.9 ml, 3 vol), and the pH of the reaction solution was adjusted to neutral using triethylamine. After the reaction solution was evaporated to dryness, it was purified by silica gel column chromatography to obtain compound 4 (3.84 g, 89%, colorless oily liquid).

[0173] TOF-MS: m / z: 540.24 [M+Na] + .

[0174] Compound 4: 1 H NMR (400 MHz, CDCl3) δ 7.65 – 7.33 (m, 7H), 5.93 – 5.73 (m,1H), 5.35 – 5.12 (m, 2H), 4.93 – 4.75 (m, 3H), 4.62 – 4.44 (m, 3H), 3.88 (dd, J = 12.0, 2.6 Hz, 1H), 3.81 – 3.60 (m, 2H), 3.48 (ddd, J = 9.6, 4.2, 2.8 Hz,1H), 2.88 – 2.75 (m, 1H), 0.92 (d, J = 2.5 Hz, 9H), 0.15 – -0.06 (m, 6H).

[0175] 13 C NMR (101 MHz, CDCl3) δ 155.05 (s), 135.28 (d, J = 31.7 Hz), 133.98(s), 133.64 (s), 133.13 (d, J = 20.3 Hz), 131.30 (s), 128.30 – 127.54 (m), 126.74 (d, J = 7.7 Hz), 126.27 – 125.63 (m), 119.18 (d, J = 5.9 Hz), 98.94 (s), 81.49 (d, J= 13.7 Hz), 76.06 (s), 75.23 (s), 74.92 (s), 68.86 (s), 62.00 (s), 58.24 (d, J = 20.9 Hz), 25.71 (s), 18.00 (s), -4.60 (dd, J = 108.8, 13.4 Hz).

[0176] Example 5

[0177] This embodiment provides a method for preparing compound A (starting compound), referring to the following synthetic route:

[0178]

[0179] Compound 12 (10 g, 0.023 mol) was dissolved in 100 ml of dichloromethane, and DMAP (0.28 g, 0.002 mol) and pyridine (2.69 g, 0.034 mol) were added sequentially. The mixture was cooled to 0 °C, and palmitoyl chloride (9.32 g, 0.034 mol) was added. After reacting for 2 hours, compound 12 was completely consumed.

[0180] The reaction solution was quenched with water (200 ml, 20 vol), and the organic layer was collected. The reaction solution was then washed sequentially with hydrochloric acid solution, sodium bicarbonate solution, and sodium chloride solution.

[0181] The reaction solution was evaporated to dryness and purified by silica gel column chromatography to obtain compound 12-A (12.9 g, 84%, white solid).

[0182] Compound 12-A (13g, 0.019mol) was dissolved in 130ml of dichloromethane, zinc powder (13g, 0.199mol) was added, and acetic acid (26ml, 2vol) was added under ice bath conditions. After stirring at room temperature for 3 hours, compound 12-A was completely consumed.

[0183] The reaction solution was washed successively with water, saturated sodium bicarbonate solution, and saturated saline solution. After rotary evaporation to dryness, the reaction solution was purified by silica gel column chromatography to obtain compound A (7.7 g, 83%, colorless oily liquid).

[0184] Compound A: 1 H NMR (400 MHz, CDCl3) δ 5.29 – 4.99 (m, 1H), 2.52 (qd, J =15.8, 6.4 Hz, 2H), 2.21 (t, J = 7.5 Hz, 2H), 1.52 (dd, J= 13.9, 7.0 Hz, 4H),1.18 (s, 42H), 0.81 (t, J = 6.9 Hz, 6H).

[0185] 13 C NMR (101 MHz, CDCl3) δ 176.37 (s), 173.39 (s), 70.04 (s), 38.95(s), 34.86 – 33.54 (m), 31.93 (d, J = 1.2 Hz), 30.13 – 28.69 (m), 25.06 (d, J =10.3 Hz), 22.69 (s), 14.10 (s).

[0186] Example 6

[0187] This embodiment provides a method for preparing compound C (starting compound), referring to the following synthetic route:

[0188]

[0189] Compound 12 (10 g, 0.023 mol) was dissolved in 100 ml of dichloromethane, and DMAP (0.28 g, 0.002 mol) and pyridine (2.69 g, 0.034 mol) were added sequentially. The mixture was cooled to 0 °C, and lauroyl chloride (7.44 g, 0.034 mol) was added. After reacting for 2 hours, compound 12 was completely consumed.

[0190] The reaction solution was quenched with water (200 ml, 20 vol), and the organic layer was collected. The reaction solution was washed successively with hydrochloric acid solution, sodium bicarbonate solution, and sodium chloride solution. After rotary evaporation to dryness, the reaction solution was purified by silica gel column chromatography to obtain compound 12-C (12 g, 85.7%, white solid).

[0191] Compound 12-C (12 g, 0.019 mol) was dissolved in 130 ml of dichloromethane, zinc powder (12 g, 0.183 mol) was added, and acetic acid (24 ml, 2 vol) was added under ice bath conditions. After stirring at room temperature for 3 hours, compound 12-C was completely consumed.

[0192] The reaction solution was washed successively with water, saturated sodium bicarbonate solution, and saturated saline solution. After rotary evaporation to dryness, the reaction solution was purified by silica gel column chromatography to obtain compound C (6.5 g, 80%, colorless oily liquid).

[0193] Compound C: 1H NMR (400 MHz, CDCl3) δ 5.20 – 5.07 (m, 1H), 2.53 (qd, J =15.8, 6.4 Hz, 2H), 2.21 (t, J = 7.5 Hz, 2H), 1.68 – 1.43 (m, 4H), 1.19 (s,34H), 0.81 (t, J = 6.8 Hz, 6H).

[0194] 13 C NMR (101 MHz, CDCl3) δ 176.44 (s), 173.33 (s), 69.99 (s), 38.92 (s), 34.23 (d, J = 51.8 Hz), 31.92 (s), 30.11 – 28.76 (m), 25.06 (d, J = 10.3Hz), 22.69 (s), 14.11 (s).

[0195] Example 7

[0196] This embodiment provides a method for preparing compound 5, referring to the following synthetic route:

[0197]

[0198] Compound A (6.4 g, 13.26 mmol) was dissolved in 43 ml of dichloromethane, and EDCI (2.55 g, 13.26 mmol) was added under ice bath conditions.

[0199] After stirring for 0.5 hours, a solution of compound 4 (4.3 g, 8.288 mmol) in dichloromethane (43 ml, 10 vol) was added.

[0200] Compound 4 was completely consumed after reacting at room temperature for 4 hours. The reaction solution was washed and separated using saturated brine (100 ml). Purification by rotary evaporation and silica gel column chromatography (petroleum ether:ethyl acetate = 10:1) yielded compound 5 (7 g, 85%, colorless oily liquid). Its 1H NMR spectrum is shown below. Figure 1 See mass spectrum Figure 2 .

[0201] TOF-MS: m / z 1004.67 [M+Na] + .

[0202] Compound 5: 1H NMR (400 MHz, CDCl3) δ 7.79 – 7.25 (m, 7H), 5.85 (d, J = 8.9Hz, 1H), 5.72 (ddt, J = 16.2, 10.6, 5.7 Hz, 1H), 5.18 (dd, J = 17.2, 1.4 Hz, 1H),5.09 (dd, J = 10.4, 1.1 Hz, 1H), 5.02 – 4.91 (m, 2H), 4.75 (dt, J = 18.8, 9.7 Hz,3H), 4.50 – 4.32 (m, 2H), 3.88 – 3.70 (m, 2H), 3.71 – 3.60 (m, 2H), 3.41(ddd, J = 9.5, 4.2, 2.8 Hz, 1H), 2.37 (dt, J = 17.5, 8.8 Hz, 1H), 2.32 – 2.16 (m,3H), 1.77 (dt, J = 14.5, 7.3 Hz, 1H), 1.23 – 1.11 (m, 46H), 0.81 – 0.77 (m,15H), 0.08 – -0.03 (m, 6H)。

[0203] 13 C NMR (101 MHz, CDCl3) δ 176.37 (s), 173.39 (s), 155.05 (s), 135.28(d, J = 31.7 Hz), 133.98 (s), 133.64 (s), 133.13 (d, J = 20.3 Hz), 131.30 (s),128.30 – 127.54 (m), 126.74 (d, J = 7.7 Hz), 126.27 – 125.63 (m), 119.18 (d, J =5.9 Hz), 98.94 (s), 81.49 (d, J = 13.7 Hz), 76.06 (s), 75.23 (s), 74.92 (s),70.04 (s), 68.86 (s), 62.00 (s), 58.24 (d,J = 20.9 Hz), 38.95 (s), 34.86 –33.54 (m), 31.93 (d, J = 1.2 Hz), 30.13 – 28.69 (m), 25.71 (s), 22.69 (s), 25.06(d, J = 10.3 Hz), 18.00 (s), -4.60 (dd, J = 108.8, 13.4 Hz), 14.10 (s).

[0204] Example 8

[0205] This embodiment provides a method for preparing compound 6, referring to the following synthetic route:

[0206]

[0207]

[0208] Compound 5 (5 g, 5.10 mmol) and compound B (10.3 g, 8.16 mmol, synthesis and preparation process can be found in Chinese patent application CN202010306826.6) were dissolved in 100 ml of dichloromethane, and molecular sieve activation powder (5 g) was added under nitrogen protection.

[0209] The reaction solution was cooled to -20°C, and TfOH (0.153 g, 1.02 mmol) was added. After reacting at room temperature for 2 hours, compound 5 was completely consumed, and the reaction solution was quenched with pyridine.

[0210] After rotary evaporation, the compound was purified by C18 packing material (eluting sequentially with CH3CN, MeOH, and CHCl3), followed by silica gel column chromatography (petroleum ether: ethyl acetate = 6:1) to give compound 6 (6.2 g, 62%, colorless oily liquid). Its 1H NMR spectrum is shown below. Figure 3 See the carbon NMR spectrum. Figure 4 See mass spectrum Figure 5 .

[0211] TOF-MS: m / z: 2055.25 [MH] - .

[0212] Compound 6: 1 H NMR (600 MHz, CDCl3) δ 7.73 – 7.64 (m, 7H), 7.60 (s, 1H), 7.41 – 7.32 (m, 5H), 7.25 (d, J= 7.8 Hz, 1H), 5.75 – 5.64 (m, 3H), 5.23 – 5.09(m, 5H), 5.05 (t, J = 9.6 Hz, 2H), 4.95 (dd, J = 12.6, 6.6 Hz, 2H), 4.81 – 4.71(m, 2H), 4.70 – 4.58 (m, 4H), 4.42 – 4.21 (m, 7H), 4.01 (d, J = 10.0 Hz, 1H),3.72 (dt, J = 14.9, 7.1 Hz, 2H), 3.65 – 3.59 (m, 2H), 3.52 (d, J = 3.3 Hz, 2H),3.30 (dd, J = 17.9, 8.6 Hz, 1H), 2.51 (qd, J = 15.6, 6.2 Hz, 2H), 2.31 (dd, J =14.9, 5.9 Hz, 1H), 2.24 – 2.13 (m, 5H), 1.56 – 1.42 (m, 8H), 1.23 – 1.10 (m,84H), 0.78 (dd, J = 12.7, 5.5 Hz, 21H), 0.02 (d, J = 19.1 Hz, 6H)。

[0213] 13 C NMR (151 MHz, CDCl3) δ 173.61 (s), 170.10 (s), 169.31 (s), 154.97(s), 153.74 (d, J = 82.1 Hz), 135.51 (d, J = 52.3 Hz), 133.11 (d, J = 41.3 Hz),132.46 – 131.84 (m), 131.35 (s), 127.92 (dd, J= 36.8, 32.8 Hz), 127.07 –125.50 (m), 119.09 – 117.85 (m), 100.06 (s), 95.87 (s), 95.33 (s), 78.87 (s),76.33 (s), 74.54 (s), 74.41 – 73.89 (m), 73.67 (s), 72.33 (s), 71.06 (s),70.14 (s), 68.50 (dd, J = 38.1, 6.8 Hz), 56.73 (d, J = 53.5 Hz), 41.77 (s), 39.79 (s), 34.49 (d, J = 14.2 Hz), 33.94 (s), 31.93 (s), 29.51 (dt, J = 51.6, 14.7 Hz), 25.66 (s), 25.15 (dd, J = 33.4, 15.7 Hz), 22.69 (s), 14.11 (s).

[0214] Example 9

[0215] This embodiment provides a method for preparing compound 7, referring to the following synthetic route:

[0216]

[0217]

[0218] Compound 6 (6 g, 2.92 mmol) was dissolved in 90 ml of dichloromethane, zinc powder (12 g, 0.184 mol) was added, and acetic acid (18 ml, 3 vol) was added under ice bath conditions. After stirring at room temperature for 3 hours, compound 6 was completely consumed.

[0219] The reaction solution was washed and separated in sequence with water (100 ml), saturated sodium bicarbonate solution (100 ml), and saturated saline solution (100 ml).

[0220] Compound 7 was purified by rotary evaporation and silica gel column chromatography (petroleum ether: ethyl acetate = 6:1) to give compound 7 (4.5 g, 82%, colorless oily liquid). Its 1H NMR spectrum is shown below. Figure 6 See the carbon NMR spectrum. Figure 7 See mass spectrum Figure 8 .

[0221] TOF-MS: m / z 1903.23 [M+Na]+ 。

[0222] More information:7: 1 H NMR (400 MHz,CDCl3 / CD3OD) δ 7.74 – 7.63 (m, 8H), 7.48 –7.36 (m, 6H), 5.88 – 5.65 (m, 3H), 5.32 – 5.24 (m, 1H), 5.24 – 5.15 (m, 4H),5.15 – 5.04 (m, 3H), 4.97 (dd, J = 19.4, 10.4 Hz, 2H), 4.75 (d, J = 8.0 Hz, 1H),4.73 (s, 2H), 4.65 (q, J = 12.2 Hz, 2H), 4.21 (d, J = 8.0 Hz, 1H), 4.15 (d, J = 9.1Hz, 1H), 3.91 – 3.73 (m, 2H), 3.72 – 3.58 (m, 4H), 3.30 (s, 2H), 2.83 (dd, J =10.2, 8.1 Hz, 1H), 2.69 (dd, J = 15.4, 3.9 Hz, 1H), 2.55 (dd, J = 15.3, 8.5 Hz, 1H), 2.42 (dd, J = 14.4, 6.2 Hz, 1H), 2.25 (dt, J = 11.3, 6.9 Hz, 5H), 1.21 (s,92H), 0.82 (d, J = 5.1 Hz, 21H), 0.07 (d, J = 6.7 Hz, 6H)。

[0223] 13 13C NMR (151 MHz, CDCl3 / CD3OD) δ 173.71 (d, J = 21.2 Hz), 170.21 (d, J =31.9 Hz), 154.73 (s), 135.00 (d, J = 55.4 Hz), 131.70 (d, J= 18.0 Hz), 131.06(s), 128.15 – 127.11 (m), 126.49 – 125.13 (m), 118.24 (d, J = 24.4 Hz), 103.22(s), 95.59 (s), 79.00 (s), 74.80 (d, J = 89.5 Hz), 73.58 (d, J = 75.1 Hz), 70.45(d, J = 106.8 Hz), 68.80 – 67.99 (m), 55.64 (d, J = 52.2 Hz), 40.19 (d, J = 198.4Hz), 34.49 – 33.81 (m), 33.42 (s), 31.60 (s), 29.16 (dt, J = 54.2, 17.6 Hz),25.50 – 24.52 (m), 22.33 (s), 17.46 (s), 13.55 (s), -5.17 (d, J = 177.1 Hz).

[0224] Example 10

[0225] This embodiment provides a method for preparing compound 8, referring to the following synthetic route:

[0226]

[0227]

[0228] Compound C (5.8 g, 13.59 mmol) was dissolved in 43 ml of dichloromethane, and EDCI (2.6 g, 13.59 mmol) was added under ice bath conditions.

[0229] After stirring for 0.5 hours, a solution of compound 7 (4.25 g, 2.26 mmol) in dichloromethane (43 ml, 10 vol) was added. After reacting at room temperature for 4 hours, compound 7 was completely consumed.

[0230] The reaction solution was washed and separated using saturated saline solution (100 ml).

[0231] After rotary evaporation, the compound was purified by C18 packing material (eluting sequentially with CH3CN, MeOH, and CHCl3), followed by silica gel column chromatography (petroleum ether: ethyl acetate = 6:1) to obtain compound 8 (3.7 g, 72%, colorless oily liquid). Its 1H NMR spectrum is shown below. Figure 9 See the carbon NMR spectrum. Figure 10 See mass spectrum Figure 11 .

[0232] TOF-MS: m / z 2311.61[M+Na] + .

[0233] Compound 8: 1 H NMR (600 MHz, CDCl3 / CD3OD) δ 7.85 – 7.66 (m, 8H), 7.49 –7.32 (m, 6H), 6.19 (d, J = 7.6 Hz, 1H), 5.86 – 5.67 (m, 4H), 5.51 – 5.43 (m,1H), 5.32 – 5.07 (m, 9H), 5.04 (dd, J = 13.1, 5.6 Hz, 1H), 5.00 (dd, J = 10.4, 9.0 Hz, 1H), 4.80 (d, J = 7.7 Hz, 1H), 4.78 – 4.73 (m, 2H), 4.72 – 4.65 (m,2H), 4.51 – 4.29 (m, 7H), 4.08 (d, J = 9.5 Hz, 1H), 3.88 – 3.76 (m, 3H), 3.75 –3.65 (m, 3H), 3.60 (ddd, J = 9.5, 4.9, 2.0 Hz, 1H), 3.53 – 3.43 (m, 1H), 2.70 –2.48 (m, 2H), 2.44 – 2.16 (m, 10H), 1.77 – 1.17 (m, 126H), 0.87 (dd, J = 14.6, 7.4 Hz, 27H), 0.09 (t, J = 13.1 Hz, 6H).

[0234] 13 C NMR (151 MHz, CDCl3 / CD3OD) δ 174.92 – 168.22 (m), 132.84 (d, J =36.7 Hz), 127.88 – 127.15 (m), 125.73 (dd, J= 52.5, 39.3 Hz), 118.43 – 117.83(m), 97.72 (d, J = 577.7 Hz), 78.76 (s), 76.53 – 76.37 (m), 74.46 (s), 74.25 –74.03 (m), 73.80 (s), 73.31 (s), 72.55 (s), 70.74 (s), 70.28 – 70.26 (m),70.21 (s), 69.77 (s), 68.23 (t, J = 47.3 Hz), 55.76 (s), 54.93 (s), 40.61 (d, J =44.7 Hz), 38.63 (s), 34.56 – 33.16 (m), 31.57 (s), 29.58 – 28.54 (m), 24.88(d, J = 64.8 Hz), 22.29 (s), 17.39 (s), 13.48 (s), -5.19 (d, J = 203.9 Hz).

[0235] Example 11

[0236] This embodiment provides a method for preparing compound 9, referring to the following synthetic route:

[0237]

[0238]

[0239] Compound 8 (2 g, 0.874 mmol) was dissolved in THF (40 mL), and a solution of pyridine hydrofluoride (20 mL, 65-70% concentration) dissolved in pyridine (60 mL) was added at –40 °C. The mixture was then heated to room temperature and stirred overnight.

[0240] After the reaction was completed, saturated sodium bicarbonate aqueous solution was added to quench the reaction, and chloroform was added for extraction multiple times.

[0241] The organic layer was dried, filtered, and concentrated, then purified using a C18 packing material (eluting sequentially with CH3CN, MeOH, and CHCl3) to give compound 9 (1.6 g, 81%, white solid). Its 1H NMR spectrum is shown below. Figure 12 See the carbon NMR spectrum. Figure 13 See mass spectrum Figure 14 .

[0242] TOF-MS: m / z2198.54[M+Na] + 。

[0243] More information: 9: 1 1H NMR (400 MHz, CDCl3 / CD3OD) δ 7.70 (dd, J = 21.0, 11.0 Hz,8H), 7.41 (dd, J = 9.7, 6.6 Hz, 6H), 5.85 – 5.61 (m, 3H), 5.36 – 4.99 (m, 12H),4.88 (d, J = 8.3 Hz, 1H), 4.76 – 4.57 (m, 4H), 4.38 – 4.22 (m, 5H), 4.12 (ddd, J = 24.1, 14.3, 7.0 Hz, 3H), 3.78 (d, J = 9.4 Hz, 1H), 3.74 – 3.59 (m, 4H), 3.54(t, J = 9.6 Hz, 1H), 3.30 (s, 2H), 2.59 (d, J = 6.0 Hz, 2H), 2.48 – 2.13 (m,10H), 1.40 (d, J = 16.3 Hz, 6H), 1.17 (d, J = 27.5 Hz, 121H), 0.83 (t, J = 6.7 Hz, 18H)

[0244] 13 1C NMR (151 MHz, CDCl3 / CD3OD) δ 155.11 (s), 135.04 (d) J = 28.5 Hz), 132.93 (d, J = 33.7 Hz), 131.72 (d, J = 19.0 Hz), 131.13 (s), 128.04 – 127.25 (m), 126.26 (d, J (12.6 Hz), 125.68 (dd, J= 33.6, 18.7 Hz), 118.54 – 118.18(m), 99.97 (s), 91.01 (s), 74.65 (s), 74.23 – 73.63 (m), 73.34 (s), 72.54 –72.40 (m), 70.71 (d, J = 52.1 Hz), 69.87 (d, J = 19.4 Hz), 68.84 – 68.16 (m), 67.75 (s), 54.49 (s), 52.16 (s), 40.83 (d, J = 16.0 Hz), 38.70 (s), 34.53 –33.56 (m), 31.68 (s), 29.78 – 28.64 (m), 24.87 (dd, J = 23.3, 7.2 Hz), 22.41(s), 13.67(s).

[0245] Example 12

[0246] This embodiment provides a method for preparing compound 10, referring to the following synthetic route:

[0247]

[0248]

[0249] Compound 9 (1.6 g, 0.736 mmol) and PPh3 (480 mg, 1.83 mmol) were added to a reaction flask. Under nitrogen protection, THF (48 mL), TEA (2.4 mL, 1.5 vol), HCOOH (1.44 mL, 0.9 vol), and Pd(Ph3P)4 (480 mg, 0.415 mmol) were added. After reacting at 25 °C for 3 h, compound 9 was completely consumed. The organic layer was dried, filtered, and concentrated. Purification was then performed using a C18 packing material (eluting sequentially with CH3CN, MeOH, and CHCl3) to obtain compound 10 (1.53 g, 97%, pale yellow solid). Its 1H NMR spectrum is shown below. Figure 15 See the carbon NMR spectrum. Figure 16 See mass spectrum Figure 17 .

[0250] TOF-MS: m / z 2009.42 [MH] - .

[0251] Compound 10: 1H NMR (400 MHz, CDCl3 / CD3OD) δ 7.61 (dd, J = 21.0, 11.0 Hz,8H), 7.33 (dd, J = 9.7, 6.6 Hz, 6H), 5.32 – 5.03 (m, 6H), 4.81 (d, J = 8.3 Hz,1H), 4.60 (d, J = 10.0 Hz, 2H), 4.30 – 4.15 (m, 5H), 3.96 (ddd, J = 24.1, 14.3,7.0 Hz, 3H), 3.71 (d, J = 9.4 Hz, 1H), 3.67 – 3.49 (m, 4H), 3.37 (t, J = 9.6 Hz,1H), 3.20 (s, 2H), 2.79 (d, J = 6.0 Hz, 2H), 2.48 – 2.10(m, 10H), 1.24 (d, J =16.3 Hz, 6H), 1.06 (d, J = 27.5 Hz, 121H), 0.87 (t, J = 6.7 Hz, 18H)。

[0252] 13 C NMR (151 MHz, CDCl3 / CD3OD) δ 135.95 (d, J = 28.2 Hz), 133.83 –132.41 (m), 128.56 – 127.14 (m), 126.59 – 125.03 (m), 91.07 (s), 75.09 (s),74.54 (s), 73.54 (s), 72.26 – 71.93 (m), 71.26 (s), 70.25 (s), 54.31 (d, J =37.3 Hz), 45.46 (s), 41.40 (d, J = 73.1 Hz), 39.34 (s), 34.32 (dd, J = 62.1, 31.7Hz), 31.96 (d, J= 5.5 Hz), 30.66 – 28.62 (m), 26.20 – 24.50 (m), 22.69 (s), 14.10 (s).

[0253] Example 13

[0254] This embodiment provides a method for preparing compound 11 (i.e., 3D-MPL), referring to the following synthetic route:

[0255]

[0256]

[0257] Compound 10 (1.53 g, 0.761 mmol) and DDQ (2.59 g, 11.42 mmol, 15 eq) were added to a reaction flask, followed by 153 mL of CHCl3. The reaction was stopped by sonication at 30 °C for 60 min. The reaction solution was then evaporated to dryness.

[0258] Acetonitrile was added to the rotary flask and then purified by decolorization in a C18 packed column. After the excess DDQ was completely removed, the product was eluted with chloroform:methanol (3:1) to obtain the final product compound 11 (1g, 76%).

[0259] TOF-MS: m / z 1729.31 [MH] - .

[0260] Compound 11: 1 H NMR (600 MHz, CDCl3 / CD3OD) δ 5.17 – 4.98 (m, 5H), 4.59 (t, J = 7.8 Hz, 1H), 4.04 – 3.96 (m, 1H), 3.90 (d, J = 7.6 Hz, 1H), 3.85 – 3.71 (m,4H), 3.66 – 3.54 (m, 2H), 3.41 – 3.26 (m, 6H), 3.22 (dd, J = 17.4, 8.6 Hz, 1H), 2.63 – 2.21 (m, 12H), 1.54 (s, 12H), 1.20 (d, J = 6.1 Hz, 114H), 0.82 (q, J = 6.9Hz, 18H).

[0261] 13C NMR (151 MHz, CDCl3 / CD3OD) δ 174.05 (d, J = 15.6 Hz), 171.68 –170.88 (m), 170.79 – 169.87 (m), 101.05 (s), 91.26 (s), 75.05 – 74.64 (m),73.26 – 73.04 (m), 72.57 (s), 71.48 (s), 71.29 (s), 71.09 (s), 70.56 (s),70.16 (s), 60.64 – 60.46 (m), 60.46 – 60.26 (m), 60.25 – 60.07 (m), 53.93(s), 41.46 (s), 38.87 (s), 34.45 (s), 34.13 (s), 31.85 (s), 29.37 (dd, J =52.9, 21.5 Hz), 25.05 (d, J = 35.3 Hz), 22.60 (s).

[0262] Comparative Example 1:

[0263] The specific process for forming compound 11 using compound 10 is as follows:

[0264] Compound 10 (50 mg, 0.025 mmol) and Pd (400 mg) were added to a hydrogenation reactor and dissolved in THF:H2O = 4:1 (20 mL). The reaction was carried out at 1 MPa and 30 °C for 24 h.

[0265] Add one drop of triethylamine to quench the reaction, then filter and evaporate the solution to dryness.

[0266] The final product compound 11 (15 mg, 32.4%) was obtained by decolorization and purification using column chromatography with C18 packing.

[0267] TLC analysis revealed residual raw material with numerous impurities, and the raw material did not decrease with extended processing time. The yield and purity were significantly lower than in the previous examples.

[0268] Comparative Example 2

[0269] This comparative example provides a method for preparing compound 2, following the synthetic route below:

[0270]

[0271] Compound 1 (1 g, 1.65 mmol) was dissolved in 10 ml of dichloromethane, and NaH (0.12 g, 4.95 mmol) was added. Naphthylmethyl bromide (1.09 g, 4.95 mmol) was added under ice bath conditions. The mixture was stirred at room temperature for 2 hours. After reflux at 45 °C, compound 1 could not be completely consumed.

[0272] The reaction solution was quenched in ice water (10 ml), and the solution was separated. The reaction solution was then washed and separated in sequence with saturated sodium bicarbonate solution (10 ml) and saturated saline solution (10 ml).

[0273] Compound 2 was purified by rotary evaporation and silica gel column chromatography (petroleum ether: ethyl acetate = 10:1) to give compound 2 (0.12 g, 10%, colorless oily liquid).

[0274] Note: Replacing naphthylmethyl bromide with benzyl bromide results in a 13% reaction yield; however, the steric hindrance is significant, making it difficult to connect.

[0275] TOF-MS: m / z: 714.13 [M+Na] + .

[0276] In summary, (1) the present invention uses an allyl ligand to avoid subsequent hydrogenation reactions, and the reaction can be completed in 1.5 h using tetra-triphenylphosphine. The final product can be obtained after simple decolorization using a C18 packed column. This avoids the problems of numerous impurities, low yield, and complex purification methods caused by hydrogenation to remove the benzyl protecting group in the prior art. It has significantly better performance.

[0277] (2) Compared with the existing technology, which requires a palladium carbon hydrogenation reaction of more than 20 hours and repeated filtration through ion column chromatography, resulting in a low yield (only about 50%), the present invention simplifies the operation by using the Nap protecting group. After optimization, the yield of the deprotection step can reach more than 91.5%, and the purity can reach 97%. (The determination method is as follows: Determination of MPL content in BLP25 liposome vaccine by HPLC-ELSD method, Chinese Journal of Pharmaceutical Affairs, Vol. 26, No. 5, 2012, Wang Mingjuan, Wang Yan, Hu Changqin).

[0278] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing 3D-MPL, characterized in that, include: Synthesize using the sixth intermediate shown in the following structural formula: Where n1 to n6 are selected from any integers between 8 and 12; The preparation method of the sixth intermediate is as follows: In an organic solvent, in the presence of an acid-binding agent, compound 1 is reacted with allyl chloroformate to obtain compound 2; in an organic solvent, in the presence of acetic acid and zinc powder, compound 2 is reduced to obtain compound 3; in an organic solvent, in the presence of triethylsilane and dichlorophenylborane, compound 3 is selectively reduced to open the ring to obtain compound 4. Compound 4 reacts with compound A to form a first intermediate, which is compound 5 as shown in the following structural formula; the structural formula of compound A is shown below: ; In an organic solvent and in the presence of an acid catalyst, the first intermediate is glycosylated with compound B to give a second intermediate; the second intermediate is compound 6 as shown in the following structural formula; the structural formula of compound B is shown below: ; In an organic solvent, under zinc powder / acid catalysis, the Troc protecting group at the 2-position of the second intermediate is removed to obtain a third intermediate, which is compound 7 with the following structural formula; In an organic solvent, under condensing agent catalysis, the third intermediate is subjected to an amidation condensation reaction with compound C to obtain a fourth intermediate; the fourth intermediate is compound 8 as shown in the following structural formula; the structural formula of compound C is shown below: ; In an organic solvent, under desilylation catalysis, the fourth intermediate is subjected to a silyl ether protecting group removal reaction to obtain a fifth intermediate; the fifth intermediate is compound 9 as shown in the following structural formula; In an organic solvent, under palladium catalysis, the fifth intermediate is subjected to an allyloxy protecting group removal reaction to obtain the sixth intermediate; the sixth intermediate is compound 10 as shown in the following structural formula; Specifically, the sixth intermediate is synthesized according to the following synthesis path: ； Compound 10 is synthesized to form 3D-MPL via the following synthetic pathway: 。 2. The preparation method according to claim 1, characterized in that, The first intermediate is selected from any one of the compounds shown in the following structural formulas: 。 3. The preparation method according to claim 1, characterized in that, The conditions for synthesizing compound 5 include: a molar ratio of compound A to compound 4 of 1-3:1; an acylation reaction temperature of -10 to 50°C; the solvent used is a haloalkane solvent, with a mass-to-volume ratio of compound 4 to solvent of 50-200 g / L; and the condensing agent used is one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, dicyclohexylcarbodiimide, and N,N'-diisopropylcarbodiimide, with a molar ratio of the condensing agent to compound 4 of 1-5:

1. The progress of the acylation reaction is monitored, and the reaction ends when compound 4 disappears or its content no longer decreases. Post-processing is performed after the acylation reaction is completed.

4. The preparation method according to claim 1, characterized in that, The conditions for synthesizing compound 5 include: a molar ratio of compound A to compound 4 of 1-2.5:1; an acylation reaction temperature of 10 to 30°C; the solvent used is dichloromethane and / or trichloromethane; the condensing agent used is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, the molar ratio of the condensing agent to compound 4 is 1-3:1; and the reaction time is 2-12 hours. Post-processing includes washing, drying, filtration, concentration, and separation and purification of the target product.

5. The preparation method according to claim 1, characterized in that, The reaction conditions for synthesizing compound 4 include: the organic solvent is a haloalkane solvent, and the mass-to-volume ratio of compound 3 to the organic solvent is 50-200 g / L; The molar ratio of the triethylsilane to the compound 3 is 2-5:1; The molar ratio of the dichlorophenylborane to compound 3 is 2-5:1; The reaction temperature ranges from -90°C to 40°C. The reaction process was monitored, and the reaction endpoint was defined as when compound 3 disappeared or its content no longer decreased; and post-processing was performed after the reaction was completed.

6. The preparation method according to claim 5, characterized in that, The reaction conditions for synthesizing compound 4 include: the organic solvent being dichloromethane and / or trichloromethane; The molar ratio of the triethylsilane to compound 3 is 3:1; The molar ratio of the dichlorophenylborane to compound 3 is 3:1; The reaction temperature is -78℃; the reaction time is 0.5-2 hours. Post-processing includes: quenching, filtering, washing, drying, concentrating, and purifying the reaction system sequentially after the reaction is completed.

7. The preparation method according to claim 1, characterized in that, The conditions for synthesizing compound 3 include: the organic solvent is a haloalkane solvent; The mass-to-volume ratio of compound 2 to the organic solvent is 50-200 g / L; The mass ratio of the acetic acid to the compound 2 is 2~5:1; The mass ratio of the zinc powder to the compound 2 is 1~3:1; The reaction temperature is 0~30℃; The reaction process is monitored, and the reaction ends when compound 2 disappears or its content no longer decreases; and post-processing is performed after the reaction is completed.

8. The preparation method according to claim 7, characterized in that, The conditions for synthesizing compound 3 include: the organic solvent being dichloromethane and / or trichloromethane; The mass-to-volume ratio of compound 2 to the organic solvent is 100 g / L; The mass ratio of acetic acid to compound 2 is 3.5:1; The mass ratio of the zinc powder to the compound 2 is 2:1; The reaction temperature is 10-20℃; the reaction time is 3-6 h; Post-processing includes: filtering, washing, drying, concentrating, and purifying the reaction system sequentially after the reaction is completed.

9. The preparation method according to claim 1, characterized in that, The conditions for synthesizing compound 2 include: the organic solvent is a haloalkane solvent; The mass-to-volume ratio of compound 1 to the organic solvent is 50~200 g / L; The acid-binding agent is any one of pyridine, triethylamine, and tetramethylethylenediamine; The molar ratio of the acid-binding agent to compound 1 is 1~3:1; The molar ratio of allyl chloroformate to compound 1 is 2~5:1; The reaction temperature is 0~30℃; The reaction process is monitored, and the reaction ends when compound 1 disappears or its content no longer decreases. Post-processing is performed after the reaction is completed.

10. The preparation method according to claim 9, characterized in that, The conditions for synthesizing compound 2 include: the organic solvent is dichloromethane and / or trichloromethane; The mass-to-volume ratio of compound 1 to the organic solvent is 100 g / L; The acid-binding agent is tetramethylethylenediamine; The molar ratio of the acid-binding agent to compound 1 is 1~2:1; The molar ratio of allyl chloroformate to compound 1 is 3~4:1; The reaction temperature is 10~20℃; the reaction time is 1-5 h; Post-processing includes: quenching, washing, drying, filtering, concentration, and separation and purification of the reaction system after the reaction is completed.

11. The preparation method according to claim 1, characterized in that, The second intermediate is selected from any one of the compounds shown in the following structural formulas: 。 12. The preparation method according to claim 1, characterized in that, The conditions for synthesizing the second intermediate include: the organic solvent is a haloalkane solvent; The mass-to-volume ratio of the first intermediate to the organic solvent is 50~200 g / L; The acid catalyst is one or more of trifluoromethanesulfonic acid, trimethylsilyl trifluoromethanesulfonic acid, and trifluoromethanesulfonic anhydride; The molar ratio of the acid catalyst to the first intermediate is 3~5:1; The molar ratio of compound B to the first intermediate is 5:8~10; The reaction temperature is -10℃ to -40℃; The glycosylation reaction was monitored, and the reaction endpoint was defined as the disappearance of the first intermediate or the glycosylation content no longer decreasing. Post-processing was performed after the reaction was completed.

13. The preparation method according to claim 12, characterized in that, The conditions for synthesizing the second intermediate include: the organic solvent is dichloromethane and / or trichloromethane; The acid catalyst is trifluoromethanesulfonic acid; The molar ratio of the acid catalyst to the first intermediate is 4~5:1; The molar ratio of compound B to the first intermediate is 5:8; The reaction temperature is -20℃; the reaction time is 2h-12h. Post-processing includes: quenching the reaction system after the reaction is completed, concentration, and separation and purification.

14. The preparation method according to claim 1, characterized in that, The third intermediate is selected from any one of the compounds shown in the following structural formulas: 。 15. The preparation method according to claim 1, characterized in that, The conditions for synthesizing the third intermediate include: the organic solvent is a haloalkane solvent; The mass-to-volume ratio of the second intermediate to the organic solvent is 50~200 g / L; The acid is selected from one or more of acetic acid, hydrochloric acid, and sulfuric acid; The mass-to-volume ratio of the acid to the second intermediate is 1~5 g / mL; The molar ratio of the zinc powder to the second intermediate is 20~15:1; The reaction temperature is 10℃~30℃; The reaction process is monitored, and the reaction ends when the second intermediate disappears or its content no longer decreases. Post-processing is performed after the reaction is completed.

16. The preparation method according to claim 15, characterized in that, The conditions for synthesizing the third intermediate include: the organic solvent is dichloromethane and / or trichloromethane; The acid is acetic acid; The mass-to-volume ratio of the acid to the second intermediate is 3 g / mL; The molar ratio of the zinc powder to the second intermediate is 16:1; The reaction temperature was room temperature; the reaction time was 2-6 hours. Post-processing includes washing and purifying the reaction system sequentially after the reaction is completed.

17. The preparation method according to claim 1, characterized in that, The fourth intermediate is selected from any one of the compounds shown in the following structural formulas: 。 18. The preparation method according to claim 1, characterized in that, The conditions for synthesizing the fourth intermediate include: the organic solvent is a haloalkane solvent; The mass-to-volume ratio of the third intermediate to the organic solvent is 120~200g / L; The condensing agent is one or more of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, dicyclohexylcarbodiimide, and N,N'-diisopropylcarbodiimide; The molar ratio of the condensing agent to the third intermediate is 5~10:1; The molar ratio of compound C to the third intermediate is 5~10:1; The reaction temperature is 10℃~30℃; The reaction process is monitored, and the reaction ends when the third intermediate disappears or its content no longer decreases. Post-processing is performed after the reaction is completed.

19. The preparation method according to claim 8, characterized in that, The conditions for synthesizing the fourth intermediate include: the organic solvent is dichloromethane and / or trichloromethane; The condensing agent is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride; The molar ratio of the condensing agent to the third intermediate is 6:1; The molar ratio of compound C to the third intermediate is 6:1; The reaction temperature was room temperature; the reaction time was 2-6 hours. Post-processing includes washing, evaporating, and purifying the reaction system sequentially after the reaction is complete.

20. The preparation method according to claim 1, characterized in that, The fifth intermediate is selected from any one of the compounds shown in the following structural formulas: 。 21. The preparation method according to claim 1, characterized in that, The conditions for synthesizing the fifth intermediate include: the organic solvent is a furan-based solvent; The mass-to-volume ratio of the fourth intermediate to the organic solvent can be 30-40 g / L; The desilication catalyst is HF / Py, wherein the mass fraction of Py is 65-70%; The mass-to-volume ratio of the desilication catalyst to the fourth intermediate is 50-150 g / L; The reaction temperature is 10℃~30℃; The reaction process is monitored, and the reaction ends when the fourth intermediate disappears or its content no longer decreases. Post-processing is performed after the reaction is completed.

22. The preparation method according to claim 21, characterized in that, The conditions for synthesizing the fifth intermediate include: the organic solvent is tetrahydrofuran; The mass-to-volume ratio of the desilication catalyst to the fourth intermediate is 100 g / L; The reaction was carried out at room temperature; the reaction time was 8–16 hours. Post-processing includes: quenching, extraction, concentration and purification of the reaction system after the reaction is completed.

23. The preparation method according to claim 1, characterized in that, The sixth intermediate is selected from any one of the compounds shown in the following structural formulas: 。 24. The preparation method according to claim 1, characterized in that, The conditions for synthesizing the sixth intermediate include: the organic solvent is a furan-based solvent; The mass-to-volume ratio of the fifth intermediate to the organic solvent is 30-40 g / L; The palladium catalyst is any one of tetraphenylphosphine palladium, palladium acetate, and palladium carbonate; The molar ratio of the palladium catalyst to the fifth intermediate is 7:3-5; The reaction temperature is 10℃~30℃; The reaction process is monitored, and the reaction ends when the fifth intermediate disappears or its content no longer decreases. Post-processing is performed after the reaction is completed.

25. The preparation method according to claim 24, characterized in that, The conditions for synthesizing the sixth intermediate include: the organic solvent is tetrahydrofuran; The palladium catalyst is tetraphenylphosphine palladium; The molar ratio of the palladium catalyst to the fifth intermediate is 7:4; The reaction temperature is room temperature; the reaction time is 2-6 hours. Post-processing includes: filtering, concentrating, and purifying the reaction system sequentially after the reaction is completed.

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