CN117567542A

CN117567542A - Intermediate 4 and preparation method and application thereof

Info

Publication number: CN117567542A
Application number: CN202311575473.XA
Authority: CN
Inventors: 邹元; 刘红; 周振; 王平; 邓英; 曾权
Original assignee: Hunan Kerey Pharmaceutical Co ltd
Current assignee: Hunan Kerey Pharmaceutical Co ltd
Priority date: 2023-11-24
Filing date: 2023-11-24
Publication date: 2024-02-20

Abstract

The invention discloses an intermediate 4, and a preparation method and application thereof, and belongs to the technical field of drug synthesis. The intermediate 4 has the structural formula ofA process for the preparation of intermediate 4 comprising the steps of: intermediate 3, methylene chloride and dilute hydrochloric acid were mixed and then reacted at 40-45 ℃ to give intermediate 4. The invention also provides an application of the intermediate 4 or the intermediate 4 prepared by the preparation method in the preparation of 25-hydroxy cholesterol or 25-hydroxy dehydrocholesterol. The intermediate 4 provided by the invention can synthesize 25-hydroxy cholesterol or 25-hydroxy dehydrocholesterol by adopting a shorter line, and has high yield.

Description

Intermediate 4 and preparation method and application thereof

Technical Field

The invention relates to the technical field of medicine synthesis, in particular to an intermediate 4 and a preparation method and application thereof.

Background

The cholesterol side chain is led with 25-hydroxy to obtain 25-hydroxy steroid compound, which is mainly 25 hydroxy cholesterol and 25 hydroxy dehydrocholesterol, has wide pharmacological activity including anti-inflammatory, antiviral, anti-IR injury and other functions and is closely related to the natural immunity of human. The industrial 25-hydroxy dehydrocholesterol is an important raw material for synthesizing the calcitol, the calcitol is a semi-active vitamin D3, has stronger biological activity compared with common vitamin D3, is one of the essential nutrient substances in human and animal bodies, has been widely applied to the fields of medicines, food feeds and the like at present, can be directly used for treating diseases of osteomalacia and hypothyroidism clinically, and is particularly suitable for treating vitamin D deficiency of patients with liver and kidney dysfunction. Meanwhile, the composition has wide application of inhibiting the growth of tumor cells, treating non-alcoholic fatty liver, protecting liver fibrosis and the like. 25-hydroxycholesterol, an endogenous oxidized sterol, has various production mechanisms in the body and also has various physiological effects on the human body.

The market has vigorous demands for commercialized 25-hydroxy vitamin D3, and a large-scale low-cost industrialized preparation method of the 25-hydroxy vitamin D3 is needed; the 25-hydroxy steroid compound is an important reaction raw material for preparing the 25-hydroxy vitamin D3, and a preparation method for searching for the 25-hydroxy steroid compound on a large scale is an important step for realizing the large-scale preparation of the 25-hydroxy vitamin D3.

The prior art has the difficulty that the side chain is modified to introduce 25-position hydroxyl. At present, the main construction methods are of two types: the AB ring and the side chain are respectively well constructed, and then are butted through reaction; the other is to modify the side chain of cholesterol to introduce a hydroxyl group at position 25.

Patent CN112608361a discloses a method for synthesizing 25-hydroxycholesterol using Bisnoralcohol (BA) as starting material, which route is as follows:

the route bromine substitutes a large amount of lithium bromide and lithium carbonate, the bromination cost is high, in addition, the coupling of the bromides and acrylic ester, nickel chloride and zinc powder are used to generate a large amount of solid waste, pyridine is used as a solvent, and a large amount of methyl acrylate is used, so that the odor of the two is large, the environment is not friendly, and the reaction is difficult to avoid due to the chemical property that the methyl acrylate is easy to polymerize.

The 3-trimethylsiloxy-3-methylbutylmagnesium bromide reagent adopted in the coupling process needs to be catalyzed by copper lithium reagent, the dosage of the magnesium reagent is more than 10 equivalents, the reaction can be completed, the atom economy is low, and the 3-trimethylsiloxy-3-methylbutylmagnesium bromide and copper lithium reagent are expensive, so that the cost of 25-hydroxycholesterol is high.

Patent CN103626821a discloses a process for preparing 25-hydroxycholesterol using 24-dehydrocholesterol as starting material, which route is as follows:

the route synthesizes the 2-hydroxy cholesterol through acylation, epoxy, ring opening and other reactions, but the yield is lower, the 24-dehydrocholesterol which is the starting material is not easy to obtain, and the purity requirement is higher, so that the cost is high and the mass production cannot be realized. Heavy metal salts are also used in the process, causing great pollution.

The preparation method reported at present has the defects of long route, low yield, high reagent toxicity, high price of the initial raw materials and the like. Therefore, a rapid, efficient, low-toxicity and low-cost synthetic route is needed.

Disclosure of Invention

The invention aims to overcome the technical defects, provide an intermediate 4, a preparation method and application thereof, and solve the technical problem of low line length and yield of synthesizing 25-hydroxycholesterol or 25-hydroxydehydrocholesterol in the prior art.

To achieve the above technical purpose, the present invention provides an intermediate 4 having a structural formula of

In addition, the invention also provides a preparation method of the intermediate 4, which comprises the following steps:

mixing the intermediate 3, methylene dichloride and dilute hydrochloric acid, and then reacting at 40-45 ℃ to obtain the intermediate 4; the structural formula of the intermediate 3 is

In some embodiments, the intermediate 3 is prepared by the steps of: mixing the intermediate 2, tetrahydrofuran and triphenylphosphine, then cooling to-2 ℃ to 2 ℃, sequentially adding acetone cyanohydrin and diisopropyl azodicarboxylate, and heating to 20-30 ℃ after the addition is finished to react to obtain the intermediate 3;

the structural formula of the intermediate 2 is as follows:

in some embodiments, the intermediate 2 is prepared by the steps of:

mixing ethylene glycol, triethyl orthoformate, p-toluenesulfonic acid and a starting material 1, and then heating to 65-70 ℃ for reaction to obtain an intermediate 2, wherein the structural formula of the starting material 1 is

In some embodiments, the intermediate 2 is obtained by reacting for 3-4 hours at a temperature of 65-70 ℃.

In addition, the invention also provides an application of the intermediate 4 or the intermediate 4 prepared by the preparation method in the preparation of 25-hydroxycholesterol or 25-hydroxydehydrocholesterol.

In some embodiments, the above-described applications include:

s1, mixing the intermediate 4, isopropenyl acetate and p-toluenesulfonic acid to react at 75-80 ℃ to obtain an intermediate 5A;

s2, mixing tetrahydrofuran and anhydrous lithium chloride, then adding sodium borohydride in batches at the temperature of 0-5 ℃, and then adding an intermediate 5A to obtain an intermediate 6A;

s3, mixing the intermediate 6A with tetrahydrofuran, and then adding a tetrahydrofuran solution of methyl magnesium chloride to obtain 25-hydroxycholesterol;

the structural formula of the intermediate 5A isThe structural formula of the intermediate 6A is +.>

In some embodiments, in step S1, a crystallization step is further included: after the reaction at 75-80 ℃, the organic layer of the obtained product is washed with water, then the organic layer is decompressed and concentrated, methylene dichloride is replaced by methanol, the organic layer is replaced into a thick state, and the temperature is reduced to 3-8 ℃ to obtain the intermediate 5A.

In some embodiments, the above-described applications include:

t1, mixing methanol, trimethyl orthoacetate, PTS and an intermediate 4, then reacting at 35-40 ℃, then cooling to below 10 ℃, adding triethylamine to adjust pH to 7-8, then cooling to below 5 ℃, reacting at a temperature of heat preservation, and then performing suction filtration to obtain a wet product;

t2, mixing acetone, water, chloranil and the wet product, and reacting at 38-42 ℃ to obtain a mixture 5B;

t3, mixing acetic anhydride, acetyl chloride and the mixture 5B, and then heating and refluxing to react to obtain an intermediate 6B;

t4, mixing tetrahydrofuran, sodium borohydride and anhydrous lithium chloride, and then adding an intermediate 6B at the temperature of-5 to-2 ℃ to react to obtain an intermediate 7B;

t5, mixing the intermediate 7B with tetrahydrofuran, and then adding a tetrahydrofuran solution of methyl magnesium chloride to perform heating reflux reaction to obtain 25-hydroxy dehydrocholesterol;

the structural formula of the intermediate 5B isThe structural formula of the intermediate 6B is +.>The structural formula of the intermediate 7B is

In some embodiments, in step T1, the reaction time is 2-4 hours at 35-40 ℃; and/or, in the step T3, the reflux reaction is carried out for 8-10 hours.

Compared with the prior art, the invention has the beneficial effects that: the intermediate 4 provided by the invention can synthesize 25-hydroxy cholesterol or 25-hydroxy dehydrocholesterol by adopting a shorter line, and has high yield.

Drawings

FIG. 1 is a hydrogen spectrum of intermediate 2 prepared in example 1 of the present invention.

FIG. 2 is a carbon spectrum of intermediate 2 prepared in example 1 of the present invention.

FIG. 3 is a hydrogen spectrum of intermediate 3 prepared in example 1 of the present invention.

FIG. 4 is a carbon spectrum of intermediate 3 prepared in example 1 of the present invention.

FIG. 5 is a hydrogen spectrum of intermediate 4 prepared in example 1 of the present invention.

FIG. 6 is a carbon spectrum of intermediate 4 prepared in example 1 of the present invention.

FIG. 7 is a hydrogen spectrum of 25-hydroxycholesterol obtained in example 2 of the present invention.

FIG. 8 is a carbon spectrum of 25-hydroxycholesterol produced in example 2 of this invention.

FIG. 9 is an HPLC chart of 25-hydroxycholesterol obtained in example 2 of the present invention.

FIG. 10 is a hydrogen spectrum of 25-hydroxydehydrocholesterol prepared in example 3 of the present invention.

FIG. 11 is a carbon spectrum of 25-hydroxydehydrocholesterol prepared in example 3 of the present invention.

FIG. 12 is an HPLC chart of 25-hydroxydehydrocholesterol obtained in example 3 of the present invention.

Detailed Description

In the following description reference is made to "some embodiments," "this embodiment," and examples, etc., which describe a subset of all possible embodiments, but it is to be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with one another without conflict.

If a similar description of "first/second" appears in the application document, the following description is added, in which the terms "first/second/third" are merely distinguishing between similar objects and not representing a particular ordering of the objects, it being understood that the "first/second/third" may be interchanged with a particular order or precedence, where allowed, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.

The term "and/or" in this embodiment is merely an association relationship describing an associated object, and indicates that three relationships may exist, for example, object a and/or object B may indicate: there are three cases where object a alone exists, object a and object B together, and object B alone exists.

The specific embodiment provides an intermediate 4, which is characterized by the structural formula

The specific embodiment also provides a preparation method of the intermediate 4, which comprises the following steps:

glycol, triethyl orthoformateMixing p-toluenesulfonic acid and a starting material 1, and then heating to 65-70 ℃ for reaction for 3-4 hours to obtain the intermediate 2, wherein the structural formula of the starting material 1 is

Mixing the intermediate 2, tetrahydrofuran and triphenylphosphine, then cooling to-2 ℃ to 2 ℃, sequentially adding acetone cyanohydrin and diisopropyl azodicarboxylate, and heating to 20-30 ℃ after the addition is finished to react to obtain the intermediate 3;

the structural formula of the intermediate 2 is as follows:

The specific embodiment also provides application of the intermediate 4 or the intermediate 4 prepared by the preparation method in preparation of 25-hydroxy cholesterol or 25-hydroxy dehydrocholesterol.

In some embodiments, the use of intermediate 4 in the preparation of 25-hydroxycholesterol comprises:

s1, mixing an intermediate 4, isopropenyl acetate and p-toluenesulfonic acid for reaction at 75-80 ℃, washing an organic layer of an obtained product with water, concentrating the organic layer under reduced pressure, replacing dichloromethane with methanol, replacing the dichloromethane into a thick state, and cooling to 3-8 ℃ to obtain an intermediate 5A;

In some embodiments, the use of intermediate 4 in the preparation of 25-hydroxydehydrocholesterol comprises:

t1, mixing methanol, trimethyl orthoacetate, PTS and an intermediate 4, then reacting for 2-4 hours at 35-40 ℃, then cooling to below 10 ℃, adding triethylamine to adjust pH to 7-8, then cooling to below 5 ℃ for heat preservation reaction, and then performing suction filtration to obtain a wet product;

t3, mixing acetic anhydride, acetyl chloride and the mixture 5B, and then heating and refluxing for reaction for 8-10 hours to obtain an intermediate 6B;

The prior art has the difficulty that the side chain is modified to introduce 25-position hydroxyl. At present, the main construction methods are of two types: the AB ring and the side chain are respectively well constructed, and then are butted through reaction; the other is to modify the side chain of cholesterol to introduce a hydroxyl group at position 25. The invention adopts a method which is different from the prior strategy: the intermediate 4 is obtained by constructing a carbon chain by reduction and cyanidation of the cheap cholic acid structure 1, the intermediate 4 is used as a general intermediate, after different modifications are carried out on an AB ring, the side chain is subjected to one-step simple format reaction, and the 25-hydroxy cholesterol and the 25-hydroxy dehydrocholesterol are correspondingly obtained.

The synthesis of the 25-hydroxy cholesterol and the 25-hydroxy dehydrocholesterol shares the intermediate 4, which is favorable for production amplification and productivity improvement, and the raw materials and the reaction reagents in each step are cheap and easy to obtain, the yield is high, and the cost is low; and the use of reagents with heavy metals and the like which have great damage to the environment is avoided, the method is economical and environment-friendly, and the process route is as follows:

the present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

Example 1

This example proposes an intermediate 4, prepared by the steps of:

1) Adding 100ml of ethylene glycol, 100ml of triethyl orthoformate and 0.25g of p-toluenesulfonic acid into a clean and dry reaction bottle under stirring, adding 50g of a starting material 1 after nitrogen replacement, slowly heating to 70 ℃ for reacting for 3 hours, monitoring by TLC, cooling to room temperature after the reaction is finished, adding 0.3g of triethylamine into the system for neutralizing the reaction system, adding 300ml of THF, stirring and clearing, continuously cooling to 0-5 ℃, adding 10g of lithium chloride, stirring for 10 minutes, adding sodium borohydride (2.5 g each time at intervals of 20 minutes, keeping the temperature of not more than 5 ℃) in 2 batches, keeping the temperature of 5-10 ℃ for reacting after the whole process is finished, keeping the temperature of 5-10 ℃ for quenching reaction after the reaction is finished for 3 hours, and dropwise adding 35g of acetic acid; then concentrating under reduced pressure to recover THF, concentrating dry THF, slowly adding 500ml of water into the system under stirring, and eluting solid by water; filtering, leaching the solid with water, and drying at 50 ℃ to obtain an intermediate 2, white solid, and the yield is 103%; the hydrogen and carbon spectra of intermediate 2 are shown in figures 1 and 2, respectively;

the reaction formula is:

2) Weighing 50g of intermediate 2, placing into a 1000ml three-mouth bottle, pouring 500ml of tetrahydrofuran, adding 50g of triphenylphosphine in the stirring process, cooling to about 0 ℃, dropwise adding 11.1g of acetone cyanohydrin, keeping the system at about 0 ℃, slowly dropwise adding 30g of diisopropyl azodicarboxylate (DIAD), heating up severely in the process, controlling the injection speed and keeping the temperature at about 0 ℃, and naturally heating up the reaction system to the room temperature of 25 ℃ after dropwise adding is completed; after the reaction, 100ml of water was added dropwise, stirred for 30 minutes, tetrahydrofuran was recovered by concentrating under reduced pressure, then 500ml of dichloromethane was added to extract the separated liquid, and the organic layer was concentrated to dryness to obtain a small amount of oil. Adding 250ml of acetone, heating to 40 ℃ under stirring, slowly dropwise adding 300ml of water into the system at 40 ℃, precipitating a large amount of solids along with the addition of water, and cooling to 5-10 ℃ for crystallization for 1h after the dropwise addition; filtering, drying at 50 ℃ to obtain intermediate 3, namely light yellow solid with the yield of 98%; the hydrogen and carbon spectra of intermediate 3 are shown in figures 3 and 4, respectively;

the reaction formula is:

3) Nitrogen replacement, 50g of intermediate 3, 250ml of dichloromethane and 50ml of 20% dilute hydrochloric acid are put into a 250ml three-mouth bottle, then the temperature is raised to 40 ℃ for reaction, TLC monitoring is carried out, and the reaction is completed for about 3 hours; standing and separating after the reaction is finished, washing an organic layer twice (100 ml is added each time), separating the liquid, concentrating the organic layer under reduced pressure, replacing methylene dichloride with methanol, replacing the methylene dichloride into a thick state, and cooling to about 5 ℃ for crystallization; filtering, leaching the solid with a small amount of methanol, and drying at 50 ℃ to obtain an intermediate 4 which is a white solid with a yield of 88%; the hydrogen and carbon spectra of intermediate 4 are shown in fig. 5 and 6, respectively.

The reaction formula is:

example 2

This example proposes the use of intermediate 4 prepared in example 1 for the preparation of 25-hydroxycholesterol, comprising:

s1, adding 50g of intermediate 4, 250ml of isopropenyl acetate and 1.0g of p-toluenesulfonic acid into a 100ml three-port bottle, heating to 80 ℃ for reaction under stirring, and monitoring by TLC (thin layer chromatography) to finish the reaction for about 4 hours; after the reaction is completed, cooling to room temperature, adding 1g of triethylamine, concentrating under reduced pressure at 60 ℃ to be thick, adding 200ml of methanol for replacement, refining and replacing the methanol to be thick, cooling to about 5 ℃ for crystallization for 1h, filtering, and drying at 50 ℃ to obtain an intermediate 5A, wherein the yield is 107%;

the reaction formula is:

s2, adding 300ml of tetrahydrofuran into a reaction bottle under stirring, then adding 7g of anhydrous lithium chloride, stirring until the anhydrous lithium chloride is completely dissolved, and cooling to 0-5 ℃. 7.5g of sodium borohydride was added in 3 portions, each at 10 minutes intervals, to ensure that the temperature was controlled below 5℃throughout the process. Stirring for 0.5 hours at 0-5 ℃ after adding sodium borohydride, slowly adding 50g of intermediate 5A, keeping the reaction below 10 ℃ after adding, and monitoring by TLC; after the reaction of the raw materials is completed, the reaction solution is slowly added into 750ml of water, glacial acetic acid is slowly added dropwise at the temperature below 30 ℃ until the pH is adjusted to 4. After the pH is adjusted to be in place, the tetrahydrofuran is recovered by decompression concentration, and 500ml of DCM is added for extraction and liquid separation is carried out; concentrating the organic layer under reduced pressure, refining by replacing methanol, cooling to about 10deg.C, vacuum filtering, and drying the solid at 50deg.C to obtain intermediate 6A as white solid with 86% yield;

the reaction formula is:

s3, adding 50g of intermediate 6A and 250ml of tetrahydrofuran into a reaction bottle, and stirring for dissolution; nitrogen replacement, slowly dropwise adding 200ml of tetrahydrofuran solution (3 mol/L) of methyl magnesium chloride, heating and refluxing for reaction after dropwise adding, and monitoring by TLC (thin layer chromatography) for about 12 hours; after the reaction is finished, cooling to room temperature, slowly pouring the reaction system into 800ml of water, regulating the PH to 3 by using concentrated hydrochloric acid, concentrating dry tetrahydrofuran under reduced pressure, separating out the material by water, filtering to obtain a wet 25-hydroxycholesterol product, and drying at 50 ℃ to obtain a crude product; adding 300ml of dichloromethane and 300ml of methanol into the obtained dry crude product for dissolution, concentrating under reduced pressure at 40 ℃, discharging by replacing methanol, filtering, and drying the solid at 50 ℃ to obtain a refined product of 25 hydroxy cholesterol, wherein the yield is 105%, and the purity is more than 98%; the hydrogen and carbon spectra of 25-hydroxycholesterol are shown in figures 7 and 8, respectively; the HPLC profile of 25 hydroxycholesterol is shown in fig. 9;

the reaction formula is:

example 3

This example proposes the use of intermediate 4 prepared in example 1 for the preparation of 25-hydroxydehydrocholesterol comprising:

adding 200ml of methanol and 75ml of trimethyl orthoacetate into a reaction bottle, replacing with nitrogen until 1gPTS is added, stirring and completely dissolving under the protection of nitrogen, and adding 50g of intermediate 4; heating to 35-40 ℃ for reaction for 3 hours, and sampling the spot plate until the raw materials are basically reacted completely. After the reaction is completed, the temperature is reduced to below 10 ℃, and triethylamine is slowly added to adjust the PH to 8; cooling to below 5 ℃, preserving heat, stirring for 0.5h, carrying out suction filtration, and directly putting wet products into a next reaction without drying;

feeding for the second time: 350ml of acetone and 50ml of tap water are added into a reaction bottle, and 30g of tetrachlorobenzoquinone and wet materials in the previous procedure are added under stirring. Heating to the internal temperature of 38-42 ℃ for reaction for 2 hours, and fully reacting the sample point plate with the etherate. Concentrating to recover acetone, cooling, adding DCM into the solid, stirring to dissolve, and filtering. Concentrating the organic layer under reduced pressure, concentrating DCM under reduced pressure, replacing with 5% sodium hydroxide solution, precipitating a large amount of solid after the DCM is concentrated to dryness, cooling to below 15 ℃, carrying out suction filtration, washing the solid with water, and drying at 55 ℃ to obtain intermediate 5B with a yield of 97%;

the reaction formula is:

100ml of acetic anhydride and 100ml of acetyl chloride are added into a reaction bottle and stirred. Nitrogen displacement was performed, and 50g of 5B was charged. And heating and refluxing for reaction for 8-10 hours. Sampling TLC monitoring; after the reaction is completed, the internal temperature is controlled to be about 60-70 ℃, the mixture is concentrated to be thick under reduced pressure, the temperature is reduced to be below 30 ℃,300ml of DCM is added, the mixture is stirred and reduced to be below 5 ℃, new methanol is slowly added dropwise at 0.5v, and the internal temperature is strictly controlled to be below 10 ℃. After the addition was completed, stirring was continued for 30 minutes. Concentrated to small volume under reduced pressure, methanol was displaced three times (2+2+1v). Cooling to about 10 ℃ for crystallization. Suction filtering, leaching with a small amount of methanol, and drying at 40-45 ℃ to obtain an intermediate 6B with a yield of 95%;

the reaction formula is:

200ml of tetrahydrofuran and 6.5g of sodium borohydride are weighed into a reaction bottle under stirring, and then 3.5g of anhydrous lithium chloride is weighed into the reaction bottle. Cooling to-5 ℃ under stirring. Then 50g of 6B is added, and the reaction is carried out for 8 hours at the temperature of minus 5 ℃ after the addition. After the reaction is finished, slowly adding the second reaction solution into 500ml of water, slowly dropwise adding glacial acetic acid to adjust the pH to 4, stirring for 2 hours, carrying out suction filtration, washing a filter cake to be neutral by using drinking water, carrying out suction drying to obtain a wet product, and drying to obtain an intermediate 7B, wherein the yield is 88.9%;

the reaction formula is:

t5, adding 50g7B and 250ml tetrahydrofuran into a reaction bottle, stirring and dissolving; nitrogen replacement, slowly dropwise adding 200ml of tetrahydrofuran solution (3 mol/L) of methyl magnesium chloride, heating and refluxing for reaction after dropwise adding, and monitoring by TLC (thin layer chromatography) for about 12 hours; after the reaction is finished, cooling to room temperature, slowly pouring the reaction system into 800ml of water, regulating the pH to 3 by using concentrated hydrochloric acid, concentrating dry tetrahydrofuran under reduced pressure, separating out the material by water, filtering to obtain a wet 25-hydroxydehydrocholesterol product, and drying at 50 ℃ to obtain a crude product; adding 300ml of dichloromethane and 300ml of methanol into the obtained dry crude product for dissolution, concentrating under reduced pressure at 40 ℃, discharging by replacing methanol, filtering, and drying the solid at 50 ℃ to obtain a refined product of 25 hydroxy dehydrocholesterol, wherein the yield is 105%, and the purity is more than 98%; the hydrogen and carbon spectra of 25-hydroxydehydrocholesterol are shown in figures 10 and 11, respectively; the HPLC profile of 5-hydroxydehydrocholesterol is shown in FIG. 12.

The reaction formula is:

the above-described embodiments of the present invention do not limit the scope of the present invention. Any other corresponding changes and modifications made in accordance with the technical idea of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. An intermediate 4, characterized in that the structural formula is

2. A process for the preparation of intermediate 4 according to claim 1, comprising the steps of:

3. A process for the preparation of intermediate 4 according to claim 2, wherein said intermediate 3 is prepared by the steps of: mixing the intermediate 2, tetrahydrofuran and triphenylphosphine, then cooling to-2 ℃ to 2 ℃, sequentially adding acetone cyanohydrin and diisopropyl azodicarboxylate, and heating to 20-30 ℃ after the addition is finished to react to obtain the intermediate 3;

the structural formula of the intermediate 2 is as follows:

4. a process for the preparation of intermediate 4 according to claim 3, wherein intermediate 2 is prepared by the steps of:

5. The process for producing intermediate 4 according to claim 4, wherein the intermediate 2 is obtained by reacting at 65 to 70℃for 3 to 4 hours.

6. Use of an intermediate 4 according to claim 1 or an intermediate 4 prepared according to the preparation method of any one of claims 1 to 5 for the preparation of 25-hydroxycholesterol or 25-hydroxydehydrocholesterol.

7. The use according to claim 6, characterized in that it comprises:

8. The use according to claim 7, further comprising a crystallization step in step S1: after the reaction at 75-80 ℃, the organic layer of the obtained product is washed with water, then the organic layer is decompressed and concentrated, methylene dichloride is replaced by methanol, the organic layer is replaced into a thick state, and the temperature is reduced to 3-8 ℃ to obtain the intermediate 5A.

9. The use according to claim 5, characterized in that it comprises:

the structural formula of the intermediate 5B isThe structural formula of the intermediate 6B isThe structural formula of the intermediate 7B is

10. Use according to claim 9, characterized in that in step T1 the reaction time is 2-4 hours at 35-40 ℃; and/or, in the step T3, the reflux reaction is carried out for 8-10 hours.