Preparation method of 4, 5-position epoxy compound of steroid compound

Abstract

The invention discloses a preparation method of a steroid compound 4, 5-position epoxy compound, and relates to the technical field of organic matter synthesis methods, 17beta-hydroxy-2, 4-ene-androstane [2, 3-d] isoxazole, a medium polar solvent, hydrogen peroxide and an anhydride reagent are used as raw materials for reaction, then alcohol recrystallization is carried out, and the compound 4, 5-position epoxy compound is obtained. Finally, a target product, namely the 4 alpha, 5 alpha-epoxy-17 beta-hydroxyl-2-ene-androstane [2, 3-d] isoxazole, is obtained. The medium polar solvent comprises dichloromethane and chloroform; the anhydride reagents are acetic anhydride and acetic acid. The preparation method provided by the invention has the advantages of short process reaction time and few byproducts, is favorable for improving the purity of the product, and has important guiding significance for the synthesis of subsequent derivative products.

Description

Technical Field

[0001] The present invention relates to the technical field of organic compound synthesis, and more particularly to a method for preparing steroid compound 4- and 5-epoxy compounds. Background Art

[0002] Trilostane (4α,5α-epoxy-2-cyano-androst-2-ene-3,17β-diol) was developed by Sterling Pharmaceuticals in the United States and first launched in the UK in 1980. It is primarily used for Cushing's syndrome (hypercortisolism) and primary aldosteronism. In 2002, Bioenvision further developed it into a novel anti-estrogen drug with a novel mechanism of action for the treatment of advanced breast cancer in postmenopausal women. Existing clinical data demonstrates its efficacy significantly superior to aromatase inhibitors, the current standard second-line treatment. Due to its excellent clinical efficacy, good tolerability, and safety profile, it has gradually attracted attention in recent years.

[0003] In the prior art, the process steps for synthesizing trilostane generally involve the step of directed synthesis of 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole. The reaction process for preparing 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole by the conventional process is as follows:

[0004]

[0005] It can be seen that the reaction process uses meta-chloroperbenzoic acid as an oxidant. However, the reaction time is as long as 12 hours. In addition to the target product, the resulting product also contains a large amount of meta-chlorobenzoic acid, a by-product of meta-chloroperbenzoic acid. Due to the good solubility of this compound, it is impossible to take effective measures to remove it completely, and the target product 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole with high purity cannot be obtained, resulting in low yield of subsequent products and increased cost.

[0006] Therefore, there is a great need to develop a technology for the targeted synthesis of this compound. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a method for preparing steroidal 4- and 5-epoxy compounds to solve the defects of the prior art, such as long reaction time, difficulty in separating by-products and products, low purity of the obtained target product, great difficulty in purification, high cost and low yield.

[0008] To achieve the above object, the technical solution of the present invention is as follows:

[0009] A method for preparing a steroid compound having 4 and 5 epoxy groups, comprising the following steps:

[0010] (1) Reagent A having a structure shown in Formula 1 is mixed with solvent A, and an excess amount of reagent B relative to reagent A is added, followed by dropwise addition of hydrogen peroxide. After the reaction is complete, a crude product containing the compound shown in Formula 2 is obtained. The reaction scheme is shown below:

[0011]

[0012] (2) Purify the crude product to obtain:

[0013] Wherein, the reagent B is a carboxylic acid;

[0014] Reagent B is added in excess relative to reagent A, specifically in excess by molar ratio.

[0015] In the present invention, when solvent A is dichloromethane and reagent B is acetic anhydride, the reaction formula involved is as follows:

[0016]

[0017] Furthermore, in step (1), the solvent A is one or both of chloroform and dichloromethane; the carboxylic acid includes acetic acid or acetic anhydride; the reagent A is mixed with the solvent A, cooled to -3°C to 8°C, and then an excess of the reagent B is added; preferably, the temperature is 0 to 5°C.

[0018] Furthermore, in step (1), after the hydrogen peroxide is added dropwise, the reaction temperature is 15°C to 35°C, preferably 20°C to 30°C, and the reaction time is 4 to 10 hours, preferably 4-6 hours.

[0019] Furthermore, in step (1),

[0020] The weight-to-volume ratio of reagent A to solvent A is 1 g:5-10 ml, preferably 1 g:5-7 ml;

[0021] The molar ratio of reagent A to reagent B is 1:4-8, preferably 1:4-6.

[0022] Furthermore, in step (1), the concentration of the hydrogen peroxide is above 27% (mass concentration); and the molar ratio of reagent A to hydrogen peroxide is 1:4-8.

[0023] Furthermore, in step (1), after the reaction is completed, a quenching agent is added to quench the reaction, the pH is adjusted to weak alkalinity, and a crude product containing the compound represented by formula 2 is obtained after washing, layering, drying, and concentration.

[0024] Furthermore, in step (1), the quencher is one of a saturated sodium bisulfite aqueous solution and a saturated sodium sulfite aqueous solution; the weight volume ratio of the reagent A to the quencher is 1 g:5-10 ml, preferably 1 g:5-7 ml;

[0025] The pH value is adjusted to a weak base by using a weak alkaline saturated solution to adjust the pH value to 7-8;

[0026] The weak alkaline saturated solution is one of sodium carbonate, potassium carbonate, and sodium bicarbonate saturated aqueous solution.

[0027] Furthermore, in step (1), the drying reagent is one of anhydrous sodium sulfate, anhydrous magnesium sulfate, and a saturated sodium chloride aqueous solution.

[0028] Furthermore, in step (2), specifically:

[0029] The crude product obtained in step (1) is dissolved in solvent B, water is slowly added under heat preservation, a solid is precipitated, the solid is cooled and kept warm, and then filtered and dried under vacuum to obtain the purified compound of formula 2;

[0030] Wherein, the solvent B is an alcohol solvent.

[0031] Furthermore, in step (2), the alcohol solvent is at least one of methanol, ethanol, and isopropanol; and the weight-to-volume ratio of the reagent A to the alcohol solvent is 1 g:4-8 ml.

[0032] Furthermore, in step (2), when water is slowly added under insulation, the temperature of the added water is 20-50°C, and the insulation temperature is 15-30°C, preferably 20-30°C; the weight ratio of the reagent A to the amount of water added is 1:3-6, preferably 1:3.5-4.5.

[0033] Furthermore, in step (2), when filtering after cooling and heat preservation, the cooling temperature is 5-10° C. and the heat preservation time is 1-2 hours.

[0034] Furthermore, in step (2), the vacuum drying temperature is 40-70° C. and the time is 4-8 hours.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] (1) The present invention realizes the directional synthesis of a steroid compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole by a chemical method, which can shorten the process reaction time, reduce by-products, and help improve the purity of the product, and has important guiding significance for the synthesis of subsequent derivative products.

[0037] (2) The solvent in the present invention is chloroform or dichloromethane, and the water washing and layering process is easier to carry out.

[0038] (3) The present invention uses hydrogen peroxide, which reacts more thoroughly and produces fewer by-products than other oxidants.

[0039] (4) In the present invention, after recrystallization from a mixed solvent, the purity of the target compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole can reach about 99.5% (area normalization method). BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is the high-resolution mass spectrum of the target substance prepared in Example 7 of the present invention;

[0041] Figure 2 This is the liquid phase spectrum of the target product prepared in Example 7 of the present invention. DETAILED DESCRIPTION

[0042] The following description sets forth numerous specific details to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific implementations disclosed below.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0044] Unless otherwise specified, the materials and reagents used in the present invention can be obtained from commercial products in the art.

[0045] Example 1

[0046] A method for preparing a steroid compound 4,5-epoxy compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane [2,3-d] isoxazole, the reaction equation is as follows: Figure 2 As shown, the following steps are included:

[0047] S1. Disperse 30g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 150ml of chloroform (weight to volume ratio of Reagent A to chloroform: 1:5). Cool to 0-5°C and add 23.0g of acetic acid to form a mixed solution (molar ratio of Reagent A to acetic acid: 1:4). Slowly add 48.4g of 27% hydrogen peroxide (molar ratio of Reagent A to hydrogen peroxide: 1:4) at this temperature. Incubate at 20°C for 6 hours, allow to stand, allow the layers to separate, and quench the organic layer with 150g of saturated sodium sulfite solution (weight ratio of Reagent A to saturated sodium sulfite: 1:5). Wash the organic layer with saturated sodium carbonate solution, adjust the pH to 7, allow to stand, allow the layers to separate, and then dry the organic layer with saturated sodium chloride solution. Allow to stand, allow the layers to separate, and then concentrate the organic layer to dryness under reduced pressure to obtain Intermediate A.

[0048] S2. Intermediate A was dissolved in 120 ml of ethanol, with the weight-to-volume ratio of reagent A to ethanol being 1:4. After heating to dissolve, 105 g of water was slowly added dropwise at 20°C, with the weight ratio of reagent A to water being 1:3.5. A solid precipitated, and the mixture was cooled to 5-10°C and filtered. The filter cake was vacuum-dried at 40°C for 6 hours to obtain 26.8 g of an off-white solid, namely 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole, in a yield of 85%.

[0049] Example 2

[0050] A method for preparing a steroid compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole at the 4 and 5 positions of the steroid compound comprises the following steps:

[0051] S1. Disperse 30g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 180ml of chloroform (weight to volume ratio of Reagent A to chloroform: 1:6). Cool to 0-5°C and add 28.8g of acetic acid to form a mixed solution (molar ratio of Reagent A to acetic acid: 1:5). Slowly add 60.4g of 27% hydrogen peroxide (molar ratio of Reagent A to hydrogen peroxide: 1:5) at this temperature. Incubate at 25°C for 5 hours, allow to stand, allow the layers to separate, and quench the organic layer with 180g of saturated sodium bisulfite solution (weight ratio of Reagent A to saturated sodium bisulfite: 1:6). Wash the organic layer with saturated sodium carbonate solution, adjust the pH to 7, allow to stand, allow the layers to separate, and then dry the organic layer with saturated sodium chloride solution. Allow to stand, allow the layers to separate, and then concentrate the organic layer to dryness under reduced pressure to obtain Intermediate A.

[0052] S2. Intermediate A was dissolved in 150 ml of ethanol, with the weight-to-volume ratio of reagent A to ethanol being 1:5. After heating to dissolve, 120 g of water was slowly added dropwise at 25°C, with the weight ratio of reagent A to water being 1:4. A solid precipitated, and the mixture was cooled to 5-10°C and filtered. The filter cake was vacuum-dried at 50°C for 6 hours to obtain 27.7 g of an off-white solid, namely 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole, in a yield of 88%.

[0053] Example 3

[0054] A method for preparing a steroid compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole at the 4 and 5 positions of the steroid compound comprises the following steps:

[0055] S1. Disperse 30g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 210ml of chloroform (weight to volume ratio of Reagent A to chloroform: 1:7). Cool to 0-5°C and add 34.6g of acetic acid to form a mixed solution (molar ratio of Reagent A to acetic acid: 1:6). Slowly add 72.5g of 27% hydrogen peroxide (molar ratio of Reagent A to hydrogen peroxide: 1:6) at this temperature. Incubate at 30°C for 4 hours, allow to stand, allow the layers to separate, and quench the organic layer with 210g of saturated sodium sulfite solution (weight ratio of Reagent A to saturated sodium sulfite: 1:7). Wash the organic layer with saturated sodium carbonate solution, adjust the pH to 7-8, allow to stand, allow the layers to separate, and then dry the organic layer with saturated sodium chloride solution. Allow to stand, allow the layers to separate, and then concentrate the organic layer to dryness under reduced pressure to obtain Intermediate A.

[0056] S2. Intermediate A was dissolved in 180 ml of ethanol, with the weight-to-volume ratio of reagent A to ethanol being 1:6. After heating to dissolve, 135 g of water was slowly added dropwise at 30°C, with the weight ratio of reagent A to water being 1:4.5. A solid precipitated, and the mixture was cooled to 5-10°C and filtered. The filter cake was vacuum-dried at 60°C for 5 hours to obtain 26.2 g of an off-white solid, namely 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole, in a yield of 83%.

[0057] Example 4

[0058] A method for preparing a steroid compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole at the 4 and 5 positions of the steroid compound comprises the following steps:

[0059] S1. Disperse 30g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 150ml of dichloromethane (weight to volume ratio of Reagent A to dichloromethane:1:5). Cool to 0-5°C and add 39.2g of acetic anhydride to form a mixed solution (molar ratio of Reagent A to acetic anhydride:1:4). Slowly add 48.4g of 27% hydrogen peroxide (molar ratio of Reagent A to hydrogen peroxide:1:4) at this temperature. Incubate at 20°C for 6 hours, allow to stand, allow the layers to separate, and quench the organic layer with 150g of saturated sodium sulfite solution (weight ratio of Reagent A to saturated sodium sulfite:1:5). Wash the organic layer with saturated sodium carbonate solution, adjust the pH to 7, allow to stand, allow the layers to separate, and then dry the organic layer with saturated sodium chloride solution. Allow to stand, allow the layers to separate, and then concentrate the organic layer to dryness under reduced pressure to yield Intermediate A.

[0060] S2. Intermediate A was dissolved in 120 ml of methanol, with the weight-to-volume ratio of reagent A to methanol being 1:4. After heating to dissolve, 105 g of water was slowly added dropwise at 30°C, with the weight ratio of reagent A to water being 1:3.5. A solid precipitated, and the mixture was cooled to 5-10°C and filtered. The filter cake was vacuum-dried at 40°C for 6 hours to obtain 28.1 g of an off-white solid, namely 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole, in a yield of 89%.

[0061] Example 5

[0062] A method for preparing a steroid compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole at the 4 and 5 positions of the steroid compound comprises the following steps:

[0063] S1. Disperse 30g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 180ml of dichloromethane (weight to volume ratio of Reagent A to dichloromethane:1:6). Cool to 0-5°C and add 49.0g of acetic anhydride to form a mixed solution (molar ratio of Reagent A to acetic anhydride:1:5). Slowly add 60.4g of 27% hydrogen peroxide (molar ratio of Reagent A to hydrogen peroxide:1:5) at this temperature. Incubate at 25°C for 5 hours, allow to stand, allow the layers to separate, and quench the organic layer with 180g of saturated sodium bisulfite solution (weight ratio of Reagent A to saturated sodium bisulfite:1:6). Wash the organic layer with saturated sodium carbonate solution, adjust the pH to 7, allow to stand, allow the layers to separate, and then dry the organic layer with saturated sodium chloride solution. Allow to stand, allow the layers to separate, and then concentrate the organic layer to dryness under reduced pressure to yield Intermediate A.

[0064] S2. Dissolve intermediate A in 150 ml of methanol at a weight-to-volume ratio of reagent A to methanol of 1:5. After heating to dissolve, slowly add 120 g of water dropwise at 25°C at a weight ratio of reagent A to water of 1:4 to precipitate a solid. Cool the solid to 5-10°C and filter. Dry the filter cake in vacuo at 50°C for 6 hours to obtain 28.5 g of an off-white solid, namely 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole, in a yield of 90%.

[0065] Example 6

[0066] A method for preparing a steroid compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole at the 4 and 5 positions of the steroid compound comprises the following steps:

[0067] S1. Disperse 30g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 210ml of dichloromethane (weight to volume ratio of Reagent A to dichloromethane:1:7). Cool to 0-5°C and add 58.8g of acetic anhydride to form a mixed solution (molar ratio of Reagent A to acetic anhydride:1:6). Slowly add 72.5g of 27% hydrogen peroxide (molar ratio of Reagent A to hydrogen peroxide:1:6) at this temperature. Incubate at 30°C for 4 hours, allow to stand, allow the layers to separate, and quench the organic layer with 210g of saturated sodium sulfite solution (weight ratio of Reagent A to saturated sodium sulfite:1:7). Wash the organic layer with saturated sodium carbonate solution, adjust the pH to 7, allow to stand, allow the layers to separate, and then dry the organic layer with saturated sodium chloride solution. Allow to stand, allow the layers to separate, and then concentrate the organic layer to dryness under reduced pressure to yield Intermediate A.

[0068] S2. Intermediate A was dissolved in 180 ml of methanol, with the weight-to-volume ratio of reagent A to methanol being 1:6. After heating to dissolve, 135 g of water was slowly added dropwise at 30°C, with the weight ratio of reagent A to water being 1:4.5. A solid precipitated, and the mixture was cooled to 5-10°C and filtered. The filter cake was vacuum-dried at 60°C for 5 hours to obtain 27.1 g of an off-white solid, namely 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole, in a yield of 86%.

[0069] Example 7

[0070] A method for preparing a steroid compound 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole at the 4 and 5 positions of the steroid compound comprises the following steps:

[0071] S1. Disperse 30g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 150ml of dichloromethane (weight to volume ratio of Reagent A to dichloromethane:1:5). Cool to 0-5°C and add 44.1g of acetic anhydride to form a mixed solution (molar ratio of Reagent A to acetic anhydride:1:4.5). Slowly add 54.4g of 27% hydrogen peroxide (molar ratio of Reagent A to hydrogen peroxide:1:4.5) at this temperature. Incubate at 30°C for 5 hours, allow to stand, allow the layers to separate, and quench the organic layer with 150g of saturated sodium sulfite solution (weight ratio of Reagent A to saturated sodium sulfite:1:5). Wash the organic layer with saturated sodium bicarbonate solution, adjust the pH to 7, allow to stand, allow the layers to separate, and then dry the organic layer with saturated sodium chloride solution. Allow to stand, allow the layers to separate, and then concentrate the organic layer to dryness under reduced pressure to yield Intermediate A.

[0072] S2. Intermediate A was dissolved in 120 ml of methanol at a weight-to-volume ratio of 1:4. After heating and dissolving, 120 g of water was slowly added dropwise at 30°C at a weight-to-volume ratio of 1:4. A solid precipitated, cooled to 5-10°C, and filtered. The filter cake was vacuum-dried at 50°C for 6 hours to obtain 29.0 g of an off-white solid, namely 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole. The yield was 92%, and the HPLC purity was 99.8%.

[0073] Figure 1 This is the high-resolution mass spectrum of the white solid obtained in this example; Figure 2 1 is the liquid phase spectrum of the white solid obtained in this example.

[0074] In Example 7 of the present invention, in S1, the molar ratio of Reagent A to acetic anhydride is 1:4.5, the solvent is dichloromethane, and the molar ratio of Reagent A to hydrogen peroxide is 1:4.5. The reaction is incubated at 30°C for 5 hours. After standing and separating, the organic layer is quenched by adding 150g of saturated sodium sulfite solution. The weight ratio of Reagent A to saturated sodium sulfite is 1:5. After standing and separating, the organic layer is washed with a weak base solvent, dried, and concentrated to dryness under reduced pressure to obtain Intermediate A. In S2, Intermediate A is dissolved in 120ml of methanol. The weight ratio of Reagent A to methanol is 1:4. 120g of water is slowly added dropwise at 30°C. The weight ratio of Reagent A to water is 1:4. 29.0g of an off-white solid is obtained. The yield is 92%, and the HPLC result is 99.8%. Compared with other examples, the yield is better, which shows that Example 7 has the best effect.

[0075] Example 8

[0076] S1. Disperse 30 g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 150 ml of dichloromethane (weight to volume ratio: Reagent A: dichloromethane: 1:5). After cooling to 0-5°C, different oxidants were added for reaction (m-CPBA, acetic anhydride + hydrogen peroxide; when m-CPBA was the oxidant, the amount of m-CPBA added was 41.3 g, and the molar ratio of Reagent A to m-CPBA was 1:2.5; when acetic anhydride + hydrogen peroxide was the oxidant, the amount of acetic anhydride added was 44.1 g, and the hydrogen peroxide was 54.4 g of 27% hydrogen peroxide). The reaction was incubated at 30°C for various times (5 h, 8 h, 12 h, and 16 h), allowed to stand, and the layers separated. The organic layer was quenched by adding 150 g of saturated sodium sulfite solution (weight ratio: Reagent A: saturated sodium sulfite: 1:5). The organic layer was washed with saturated sodium bicarbonate solution, the pH value was adjusted to 7, and the mixture was allowed to stand and separate into layers. The organic layer was then dried with saturated sodium chloride solution. The mixture was allowed to stand and separate into layers. The organic layer was concentrated to dryness under reduced pressure to obtain Intermediate A.

[0077] S2. Dissolve Intermediate A in 120 ml of methanol (weight to volume ratio of Reagent A to methanol: 1:4). After heating to dissolve, slowly add 120 g of water dropwise at 30°C (weight to volume ratio of Reagent A to water: 1:4). A solid precipitates, cools to 5-10°C, and filters. The filter cake is vacuum-dried at 50°C for 6 hours to obtain an off-white solid. The purity and yield of the product are shown in Table 1 below.

[0078] The reaction time, temperature, quality and yield of 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole obtained in this example are compared with those obtained by the traditional process.

[0079] Table 1: Effect of different oxidant reaction times on product purity and yield

[0080]

[0081] As can be seen from the table above, when the traditional process (m-CPBA as the oxidant) is used, the reaction time is as long as 16 hours. In addition to the target product, the resulting product also contains a large amount of meta-chlorobenzoic acid, a by-product of meta-chloroperbenzoic acid. The degradation products of the oxidant are difficult to remove during the post-treatment process, and the operation process is complicated. As a result, the target product 4α,5α-epoxy-17β-hydroxy-2-ene-androstane[2,3-d]isoxazole with high purity cannot be obtained, resulting in low yields and increased costs of subsequent products.

[0082] Example 9

[0083] S1. Disperse 30 g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole as Reagent A in 150 ml of dichloromethane (weight to volume ratio of Reagent A to dichloromethane: 1:5). Cool the mixture to 0-5°C. Add acetic anhydride at varying molar ratios of Reagent A to acetic anhydride (1:1.2 to 1:6) to obtain a mixed solution. At this temperature, slowly add 27% hydrogen peroxide dropwise at varying molar ratios of Reagent A to hydrogen peroxide (1:4 to 1:8). Incubate at various temperatures (20-45°C) for varying times (5-26 hours). Allow to stand and separate. Quench the organic layer by adding 150 g of saturated sodium sulfite solution (weight ratio of Reagent A to saturated sodium sulfite: 1:5). Wash the organic layer with saturated sodium bicarbonate solution, adjust the pH to 7, allow to stand, separate, and then dry the organic layer with saturated sodium chloride solution. Allow to stand and separate, and then concentrate the organic layer to dryness under reduced pressure to obtain Intermediate A.

[0084] S2. Dissolve Intermediate A in 120 ml of methanol (weight to volume ratio of Reagent A to methanol: 1:4). After heating to dissolve, slowly add 120 g of water dropwise at 30°C (weight to volume ratio of Reagent A to water: 1:4). A solid precipitates, cools to 5-10°C, and filters. The filter cake is vacuum-dried at 50°C for 6 hours to obtain an off-white solid. The purity and yield of the product are shown in Table 2 below.

[0085] Table 2: Effect of different molar ratios of reagent A to hydrogen peroxide and acetic anhydride on product yield and purity

[0086]

[0087]

[0088] From Table 2 above, we can see that:

[0089] When the molar ratio of reagent A to acetic anhydride is lower than 1:4, even if the reaction time is extended to more than 20 hours, the purity and yield of the product are less than 70%; when the molar ratio of reagent A to acetic anhydride is 1:4 to 6, the reaction time can be significantly shortened, and the purity and yield can be improved; in addition, increasing the reaction temperature will reduce the purity of the target product, increase the by-products, and reduce the yield.

[0090] Example 10

[0091] S1. Disperse 30g of 17β-hydroxy-2,4-ene-androstano[2,3-d]isoxazole (Reagent A) in 150ml of dichloromethane (weight to volume ratio of Reagent A to dichloromethane:1:5). Cool to 0-5°C and add 44.1g of acetic anhydride to form a mixed solution (molar ratio of Reagent A to acetic anhydride:1:4.5). Slowly add 54.4g of 27% hydrogen peroxide (molar ratio of Reagent A to hydrogen peroxide:1:4.5) at this temperature. Incubate at 30°C for 5 hours, allow to stand, separate the layers, and quench the organic layer with 150g of saturated sodium sulfite solution (weight ratio of Reagent A to saturated sodium sulfite:1:5). Wash the organic layer with saturated sodium bicarbonate solution, adjust the pH to 7, allow to stand, separate the layers, and then dry the organic layer with saturated sodium chloride solution. Allow to stand, separate the layers, and concentrate the organic layer under reduced pressure to dryness to yield Intermediate A.

[0092] S2. Intermediate A was dissolved in various alcohol reagents (methanol, ethanol, and isopropanol) at different mass-to-volume ratios of reagent A to alcohol reagent (1:2-4). After dissolution by heating, water was slowly added dropwise at 30°C at different mass-to-volume ratios of reagent A to water (1:1-5). A solid precipitated, cooled to 5-10°C, and filtered. The filter cake was vacuum-dried at 50°C for 6 hours to obtain an off-white solid. The purity and yield of the product are shown in Table 3 below.

[0093] Table 3: Effects of different alcohol reagents and different ratios with water on product purity and yield

[0094]

[0095] By comparing the data in Table 3 above, it is clear that in step S2, the ratio of reagent A to alcohol and water is crucial; increasing the ratio of water improves the yield of the target product, but reduces its purity; reducing the ratio of water can increase the purity of the target product, but reduces the yield. When the ratio of alcohol to water is appropriate, both purity and yield can be guaranteed.

[0096] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for preparing a steroid compound 4,5-epoxy compound, characterized in that: The following steps are involved: (1) Reagent A having a structure shown in Formula 1 is mixed with solvent A, and an excess amount of reagent B relative to reagent A is added, followed by dropwise addition of hydrogen peroxide. After the reaction is complete, a crude product containing the compound shown in Formula 2 is obtained. The reaction scheme is shown below: (2) Purify the crude product to obtain: Wherein, the reagent B is carboxylic acid.

2. The preparation method according to claim 1, characterized in that In step (1), the solvent A is one or both of chloroform and dichloromethane; the carboxylic acid includes acetic acid or acetic anhydride; the reagent A is mixed with the solvent A, cooled to -3°C to 8°C, and then an excess of the reagent B is added; preferably, the temperature is 0 to 5°C.

3. The preparation method according to claim 1, characterized in that In step (1), after the hydrogen peroxide is added dropwise, the reaction temperature is 15°C to 35°C, preferably 20°C to 30°C, and the reaction time is 4 to 10 hours, preferably 4 to 6 hours.

4. The preparation method according to claim 1, characterized in that In step (1), The weight-to-volume ratio of reagent A to solvent A is 1 g:5-10 ml, preferably 1 g:5-7 ml; The molar ratio of reagent A to reagent B is 1:4-8, preferably 1:4-6.

5. The preparation method according to claim 1, characterized in that In step (1), the concentration of the hydrogen peroxide is above 27%; the molar ratio of reagent A to hydrogen peroxide is 1:4-8.

6. The preparation method according to claim 1, characterized in that In step (1), after the reaction is completed, a quenching agent is added to quench the reaction, the pH is adjusted to weak alkalinity, and the crude product containing the compound represented by formula 2 is obtained after washing, layering, drying, and concentration.

7. The preparation method according to claim 6, characterized in that In step (1), the quencher is one of a saturated sodium bisulfite aqueous solution and a saturated sodium sulfite aqueous solution; the weight volume ratio of the reagent A to the quencher is 1 g:5-10 ml, preferably 1 g:5-7 ml; The pH value of the mixture is adjusted to a weak base by using a weak alkaline saturated solution to adjust the pH value to 7-8. The weak alkaline saturated solution is one of sodium carbonate, potassium carbonate, and sodium bicarbonate saturated aqueous solution.

8. The preparation method according to any one of claims 1 to 7, characterized in that In step (2), specifically: The crude product obtained in step (1) is dissolved in solvent B, water is slowly added under heat preservation to precipitate a solid, and the solid is cooled and kept warm before filtration and vacuum drying to obtain the purified compound of formula 2; Wherein, the solvent B is an alcohol solvent.

9. The preparation method according to claim 8, characterized in that In step (2), the alcohol solvent is at least one of methanol, ethanol, and isopropanol; and the weight-to-volume ratio of the reagent A to the alcohol solvent is 1 g:4-8 ml.

10. The preparation method according to claim 8, characterized in that In step (2), when water is slowly added under heat preservation, the temperature of the added water is 20-50°C, and the heat preservation temperature is 15-30°C, preferably 20-30°C; the weight ratio of the reagent A to the amount of water added is 1:3-6, preferably 1:3.5-4.

5.

11. The preparation method according to claim 8, characterized in that In step (2), when filtering after cooling and heat preservation, the cooling temperature is 5-10° C. and the heat preservation time is 1-2 hours.

12. The preparation method according to claim 8, characterized in that In step (2), the vacuum drying temperature is 40-70° C. and the time is 4-8 hours.

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