Preparation method of desonide single crystal

Abstract

The invention relates to the technical field of single crystal preparation, in particular to a preparation method of a desonide single crystal. The method comprises the following steps: adding a desonide sample into a solvent 1; ultrasonically dissolving to a saturated state; adding a solvent 2 into the mixture, uniformly shaking, and filtering; adding the obtained clear filtrate into a bottle, adding a solvent 3 again, and sealing with a sealing film; pricking a hole in a sealing film of the sealed bottle; standing and culturing at the temperature of 20-30 DEG C, separating out crystals, removing supernate, enabling a crystallization system to slowly reach supersaturation by controlling different solvents and solution temperature, and promoting ordered growth of the crystals to obtain the single crystal of desonide. And irradiating the single crystal by using an X-Ray diffractometer under specific conditions to obtain a diffraction pattern and diffraction data.

Description

Technical Field

[0001] The invention relates to the technical field of single crystal preparation, and in particular to a method for preparing a desonide single crystal. Background Art

[0002] Desonide (English name: Desonide) is a corticosteroid drug with strong anti-inflammatory effect. It is suitable for the treatment of various skin diseases that are effective in corticosteroid treatment, such as contact dermatitis, neurodermatitis, seborrheic dermatitis, eczema, psoriasis, lichen planus, lichen simplex, dyshidrosis, etc., and has broad market prospects.

[0003] Desonide, chemical name: 11-β, 21-dihydroxy-16α, 17α-(isopropylenedioxy)pregnane-1,4-diene-3,20-dione, its structure is shown in Formula 1:

[0004]

[0005] The properties are white or off-white crystalline powder. There are eight chiral carbon atoms in the desonide molecule. Currently, the main methods for determining the absolute configuration of chiral molecules are: (1) Organic chemistry: Organic synthesis is the earliest method for determining molecular chirality, which is mainly a chemical correlation method, that is, the target molecule is analyzed by reverse synthesis, starting from the initial known chiral compound, through chiral controlled organic chemical reactions, it is converted into the target compound, and then its absolute configuration is deduced from their optical rotation signs or corresponding gas chromatography and liquid chromatography. However, organic synthesis is always a tedious and laborious choice. (2) Nuclear magnetic resonance method: NMR technology is the preferred method for obtaining the structure of compounds. Its coupling constant and NOE spectrum are important means to obtain the relative configuration of compounds. It is suitable for the configuration confirmation of rigid structure diastereomers, but for optical (enantiomer) isomers, the signals of their NMR spectra are generally the same, that is, the NMR spectrum cannot be directly distinguished, and its absolute configuration cannot be determined. Therefore, organic chemistry and nuclear magnetic resonance methods have brought challenges to the structural identification of desonide, especially the configuration identification of chiral carbon positions. (3) X-ray diffraction method: In single crystal structure analysis, the internationally recognized parameter characterizing the absolute configuration is called the Flack parameter. When the structure analysis enters the final refinement stage, if the parameter is equal to or close to 0, or its parameter is within ±0.3, then it is generally believed that the absolute configuration is determined. The single crystal X-ray diffraction method uses less sample, is fast to measure, and has reliable and intuitive results. It can be used as a method to determine the final stereo configuration.

[0006] Desonide single crystal refers to a crystal formed by the arrangement of desonide molecules in a single and regular manner. In this crystal, all desonide molecules are arranged in the same direction and pattern to form a long-range ordered structure. The arrangement of internal atoms or molecules has a high degree of regularity and consistency, which makes the single crystal show unique uniformity and stability in physical and chemical properties, and is more suitable for medicinal use. However, the preparation of desonide single crystals in the prior art has defects, and it is difficult to obtain a well-characterized single crystal structure by X-ray diffraction. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for preparing a desonide single crystal, which is scientific and effective, and the prepared desonide single crystal can be better characterized by using an X-ray diffraction method.

[0008] In order to solve the above problems, the technical solution of the present invention is:

[0009] The method for preparing the desonide single crystal of the present invention is prepared by the following steps:

[0010] (1) Desonide sample is added to solvent 1;

[0011] (2) Ultrasonic dissolution until saturation;

[0012] (3) adding solvent 2 to the mixture obtained in step (2), shaking well, and filtering;

[0013] (4) adding the clarified filtrate obtained in step (3) into the bottle, adding solvent 3 again, and sealing with a sealing film;

[0014] (5) Punch a hole in the sealing film of the sealed bottle;

[0015] (6) culturing at 20-30° C., preferably at 25° C., until crystals precipitate, and removing the supernatant to obtain desonide single crystals;

[0016] The solvent 1 is one or more of methanol, ethanol, isopropanol, dimethyl sulfoxide, and water;

[0017] The solvent 2 is one or more of methanol, ethanol, isopropanol, dimethyl sulfoxide, and water;

[0018] The solvent 3 is one or more of methanol, ethanol, isopropanol, dimethyl sulfoxide, and water;

[0019] The solvent 1 and the solvent 2 cannot be the same solvent at the same time.

[0020] The mass volume ratio of the desonide sample described in step (1) to the solvent 1 is 500 mg: (4.5-5.5) mL.

[0021] The ultrasonic treatment time in step (2) is 5 to 30 minutes.

[0022] The mass volume ratio of the solvent 2 described in step (3) to the desonide sample is (1.5-2.5) mL:500 mg.

[0023] The filtration in step (3) is performed using a microporous filter membrane with a pore size of 0.45 μm.

[0024] The mass volume ratio of the solvent 3 described in step (4) to the desonide sample is (0.5-1.5) mL:500 mg.

[0025] The static culture time in step (6) is 5 to 20 days, preferably 10 days.

[0026] The obtained desonide single crystal has the absolute configuration of the chiral center in the molecule: {5S, 7R, 8S, 9R, 13S, 15S, 16S, 22S}. The desonide single crystal belongs to the tetragonal system, P41212 space group, and the unit cell parameters are: α=90°, β=90°, γ=90°.

[0027] The beneficial effects of the present invention are as follows:

[0028] The invention controls the difference of solvents and the temperature of the solution to slowly supersaturate the crystallization system and promote the orderly growth of crystals to obtain single crystals of desonide. The single crystals are irradiated with an X-Ray diffractometer under specific conditions to obtain diffraction patterns and diffraction data. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. In the accompanying drawings:

[0030] Figure 1 The three-dimensional structure diagram of the molecule in the desonide crystal obtained in Example 3;

[0031] Figure 2 The molecular structure of desonide obtained in Example 3 (line diagram). DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the embodiments.

[0033] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0034] Example 1

[0035] The method for preparing the desonide single crystal is prepared by the following steps:

[0036] (1) Take 500 mg of desonide sample and add it to 5 ml of methanol;

[0037] (2) Ultrasonication at 25°C for 15 min to dissolve until saturated;

[0038] (3) Add 2 ml of ethanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0039] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of water, and seal with a sealing film;

[0040] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0041] (6) The mixture was placed at 25° C. and incubated for 10 days. Crystals precipitated and the supernatant was removed to obtain single crystals of desonide (400 mg, yield: 80%, HPLC purity: 95%).

[0042] Example 2

[0043] The method for preparing the desonide single crystal is prepared by the following steps:

[0044] (1) Take 500 mg of desonide sample and add it to 5 ml of dimethyl sulfoxide;

[0045] (2) Ultrasonication at 25°C for 25 min to dissolve until saturated;

[0046] (3) Add 2 ml of water to the mixture obtained in step (2), shake well, and filter;

[0047] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of water, and seal with a sealing film;

[0048] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0049] (6) The mixture was placed at 25° C. and incubated for 10 days. Crystals precipitated and the supernatant was removed to obtain single crystals of desonide (200 mg, yield: 40%, HPLC purity: 90%).

[0050] Example 3

[0051] The method for preparing the desonide single crystal is prepared by the following steps:

[0052] (1) Take 500 mg of desonide sample and add it to 5 ml of methanol;

[0053] (2) Ultrasonication for 10 min to dissolve until saturation;

[0054] (3) Add 2 ml of isopropanol to the mixture obtained in step (2) at 25° C., shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0055] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of ethanol, and seal with a sealing film;

[0056] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0057] (6) The mixture was placed at 25° C. and incubated for 10 days. Crystals precipitated and the supernatant was removed to obtain single crystals of desonide (480 mg, yield: 96%, HPLC purity: 96%).

[0058] Example 4

[0059] The method for preparing the desonide single crystal is prepared by the following steps:

[0060] (1) Take 500 mg of desonide sample and add it to 5 ml of isopropanol;

[0061] (2) Ultrasonication at 25°C for 15 min to dissolve until saturated;

[0062] (3) Add 2 ml of methanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0063] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of water, and seal with a sealing film;

[0064] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0065] (6) The mixture was placed at 25° C. and incubated for 10 days. Crystals precipitated and the supernatant was removed to obtain single crystals of desonide (250 mg, yield: 50%, HPLC purity: 85%).

[0066] Example 5

[0067] The method for preparing the desonide single crystal is prepared by the following steps:

[0068] (1) Take 500 mg of desonide sample and add it to 5 ml of isopropanol;

[0069] (2) Ultrasonication at 25°C for 15 min to dissolve until saturated;

[0070] (3) Add 2 ml of methanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0071] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of methanol, and seal with a sealing film;

[0072] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0073] (6) The mixture was placed at 25° C. and incubated for 10 days. Crystals precipitated and the supernatant was removed to obtain single crystals of desonide (200 mg, yield: 40%, HPLC purity: 90%).

[0074] Example 6

[0075] The method for preparing the desonide single crystal is prepared by the following steps:

[0076] (1) Take 500 mg of desonide sample and add it to 5 ml of water;

[0077] (2) Ultrasonication at 25°C for 15 min to dissolve until saturated;

[0078] (3) Add 2 ml of methanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0079] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of isopropanol, and seal with a sealing film;

[0080] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0081] (6) The mixture was placed at 25° C. and incubated for 10 days. Crystals precipitated and the supernatant was removed to obtain single crystals of desonide (250 mg, yield: 50%, HPLC purity: 80%).

[0082] Example 7

[0083] The method for preparing the desonide single crystal is prepared by the following steps:

[0084] (1) Take 500 mg of desonide sample and add it to 5 ml of water;

[0085] (2) Ultrasonication at 25°C for 15 min to dissolve until saturated;

[0086] (3) Add 2 ml of isopropanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0087] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of water, and seal with a sealing film;

[0088] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0089] (6) The mixture was placed at 25° C. and incubated for 10 days. Crystals precipitated and the supernatant was removed to obtain single crystals of desonide (100 mg, yield: 20%, HPLC purity: 55%).

[0090] Example 8

[0091] The method for preparing the desonide single crystal is prepared by the following steps:

[0092] (1) Take 500 mg of desonide sample and add it to 5 ml of ethanol;

[0093] (2) Ultrasonication at 25°C for 15 min to dissolve until saturated;

[0094] (3) Add 2 ml of water to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0095] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of methanol, and seal with a sealing film;

[0096] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0097] (6) The mixture was placed at 25° C. and incubated for 10 days. Crystals precipitated and the supernatant was removed to obtain single crystals of desonide (150 mg, yield: 30%, HPLC purity: 60%).

[0098] Comparative Example 1

[0099] The method for preparing the desonide single crystal is prepared by the following steps:

[0100] (1) Take 500 mg of desonide sample and add it to 5 ml of methanol;

[0101] (2) Ultrasonication at 25°C for 20 min to dissolve until saturated;

[0102] (3) Add 2 ml of ethanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0103] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of water, and seal with a sealing film;

[0104] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0105] (6) Place the mixture at -10°C and incubate until no crystals are precipitated.

[0106] Comparative Example 2

[0107] The method for preparing the desonide single crystal is prepared by the following steps:

[0108] (1) Take 500 mg of desonide sample and add it to 5 ml of methanol;

[0109] (2) Ultrasonication at 25°C for 20 min to dissolve until saturated;

[0110] (3) Add 2 ml of ethanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0111] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of water, and seal with a sealing film;

[0112] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0113] (6) Place the mixture at -25°C and incubate until no crystals are precipitated.

[0114] Comparative Example 3

[0115] The method for preparing the desonide single crystal is prepared by the following steps:

[0116] (1) Take 500 mg of desonide sample and add it to 5 ml of isopropanol;

[0117] (2) Ultrasonication at 25°C for 10 min to dissolve until saturated;

[0118] (3) Add 2 ml of methanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0119] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of methanol, and seal with a sealing film;

[0120] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0121] (6) Place the mixture at -10°C and incubate until no crystals are precipitated.

[0122] Comparative Example 4

[0123] The method for preparing the desonide single crystal is prepared by the following steps:

[0124] (1) Take 500 mg of desonide sample and add it to 5 ml of isopropanol;

[0125] (2) Ultrasonication at 25°C for 10 min to dissolve until saturated;

[0126] (3) Add 2 ml of methanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0127] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of methanol, and seal with a sealing film;

[0128] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0129] (6) Place the mixture at -25°C and incubate until no crystals are precipitated.

[0130] Comparative Example 5

[0131] The method for preparing the desonide single crystal is prepared by the following steps:

[0132] (1) Take 500 mg of desonide sample and add it to 5 ml of methanol;

[0133] (2) Ultrasonication at 25°C for 5 min to dissolve until saturated;

[0134] (3) Add 2 ml of isopropanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0135] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of ethanol, and seal with a sealing film;

[0136] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0137] (6) Place the mixture at -10°C and incubate until no crystals are precipitated.

[0138] Comparative Example 6

[0139] The method for preparing the desonide single crystal is prepared by the following steps:

[0140] (1) Take 500 mg of desonide sample and add it to 5 ml of methanol;

[0141] (2) Ultrasonication at 25°C for 5 min to dissolve until saturated;

[0142] (3) Add 2 ml of isopropanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0143] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of ethanol, and seal with a sealing film;

[0144] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0145] (6) Place the mixture at -25°C and incubate until no crystals are precipitated.

[0146] Comparative Example 7

[0147] The method for preparing the desonide single crystal is prepared by the following steps:

[0148] (1) Take 500 mg of desonide sample and add it to 5 ml of methanol;

[0149] (2) Ultrasonication at 25°C for 5 min to dissolve until saturated;

[0150] (3) Add 2 ml of methanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0151] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of ethanol, and seal with a sealing film;

[0152] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0153] (6) Place the mixture at 25°C and incubate until no crystals are precipitated.

[0154] Comparative Example 8

[0155] The method for preparing the desonide single crystal is prepared by the following steps:

[0156] (1) Take 500 mg of desonide sample and add it to 5 ml of isopropanol;

[0157] (2) Ultrasonication at 25°C for 5 min to dissolve until saturated;

[0158] (3) Add 2 ml of isopropanol to the mixture obtained in step (2), shake well, and filter using a microporous filter membrane with a pore size of 0.45 μm;

[0159] (4) Add the clarified filtrate obtained in step (3) into a vial, add 1 ml of ethanol, and seal with a sealing film;

[0160] (5) Use a syringe needle to pierce a hole in the sealing film of the sealed vial;

[0161] (6) Place the mixture at 25°C and incubate until no crystals are precipitated.

[0162] The present invention selected the desonide single crystal obtained in Example 3 and confirmed the configuration of the chiral carbon in the desonide molecule through X-ray single crystal diffraction analysis. The data are shown in Table 1 below.

[0163] Table 1 Crystal data of desonide single crystal

[0164]

[0165]

[0166] Desonide single crystal diffraction experiment

[0167] Take out desonide crystals from the vial and select 0.3×0.2×0.1mm 3 Single crystals of different sizes were used for single crystal diffraction. They were irradiated with a Cu-Kα target ray source on a German Bruker single crystal diffractometer. The X-ray operating voltage was 50 kV, the operating current was 0.95 mA, the maximum 2θ angle was 69.717°, the detection temperature was 296 K, the number of diffraction points was 3998, the number of independent diffraction points was 2608 (Rint = 0.2041), the data integrity was 99.7%, the crystal was colorless and transparent, and belonged to the tetragonal system. The space group was P41212, and the unit cell parameters were: α=90°,β=90°,γ=90°,unit cell volume The number of molecules in the unit cell is Z = 8, there is 1 molecule in the independent area of ​​the unit cell, and the crystal density is 1.278 g / cm 3 The results showed that there were eight chiral carbon atoms in the desonide molecule, and their configurations were 5S, 7R, 8S, 9R, 13S, 15S, 16S, and 22S, which were consistent with those reported in the literature.

[0168] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a desonide single crystal, characterized in that: Prepared by the following steps: (1) Desonide sample is added to solvent 1; (2) Ultrasonic dissolution until saturation; (3) adding solvent 2 to the mixture obtained in step (2), shaking well, and filtering; (4) adding the clarified filtrate obtained in step (3) into the bottle, adding solvent 3 again, and sealing with a sealing film; (5) Punch a hole in the sealing film of the sealed bottle; (6) incubating at 20-30° C. until crystals precipitate, and removing the supernatant to obtain desonide single crystals; The solvent 1 is one or more of methanol, ethanol, isopropanol, dimethyl sulfoxide, and water; The solvent 2 is one or more of methanol, ethanol, isopropanol, dimethyl sulfoxide, and water; The solvent 3 is one or more of methanol, ethanol, isopropanol, dimethyl sulfoxide, and water; The solvent 1 and the solvent 2 cannot be the same solvent at the same time.

2. The method for preparing a desonide single crystal according to claim 1, characterized in that: The mass volume ratio of the desonide sample described in step (1) to the solvent 1 is 500 mg: (4.5-5.5) mL.

3. The method for preparing a desonide single crystal according to claim 1, characterized in that: The ultrasonic treatment time in step (2) is 5 to 30 minutes.

4. The method for preparing a desonide single crystal according to claim 1, characterized in that: The mass volume ratio of the solvent 2 described in step (3) to the desonide sample is (1.5-2.5) mL:500 mg.

5. The method for preparing a desonide single crystal according to claim 1, characterized in that: The filtration in step (3) is performed using a microporous filter membrane with a pore size of 0.45 μm.

6. The method for preparing a desonide single crystal according to claim 1, characterized in that: The mass volume ratio of the solvent 3 described in step (4) to the desonide sample is (0.5-1.5) mL:500 mg.

7. The method for preparing a desonide single crystal according to claim 1, characterized in that: The static culture time in step (6) is 5 to 20 days.

8. The method for preparing a desonide single crystal according to claim 1, characterized in that: The temperature of the static culture in step (6) is 25°C.

9. The method for preparing a desonide single crystal according to claim 7, characterized in that: The static culture time in step (6) is 10 days.

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