CN106674321A - Preparation method of sofosbuvir crystal form 6 - Google Patents

Abstract

The invention provides a preparation method of a sofosbuvir crystal form 6. The preparation method comprises the following steps: mixing a solution formed by a sofosbuvir coarse product and a water-containing alcohol solvent with alkane, and performing crystallization to obtain the sofosbuvir crystal form 6. According to the sofosbuvir coarse product, the mass content of a special impurity II is not greater than 3%, the mass content is percentage of mass of the specific impurity II in the sofosbuvir coarse product, and the specific impurity II is pentafluorophenol. The preparation method provided by the invention is simple and efficient in crystallization process, short in step, high in yield, good in repeatability and obvious in refining effect of the specific impurity II; and the obtained product is good in stability and high in purity, meets the demands of an oral solid preparation, meets the demands (HPLC purity is greater than 99.50% and the maximum single impurity is smaller than 0.1%) of raw material medicines, is green and environmental-friendly, and is suitable for industrial production.

Description

The preparation method of sofosbuvir crystal form 6

technical field

The present invention relates to a preparation method of sofosbuvir crystal form 6.

Background technique

Sofosbuvir (trade name: Sovaldi, generic name: Sofosbuvir, formerly known as GS-7977, PSI-7977), chemical name: (S)-2-{[(2R,3R,4R,5R)-5- (2,4-Dioxo-3,4-dihydro-2H-pyrimidin-1-yl)-4-fluoro-3-hydroxy-4-methyl-tetrahydrofuran-2-ylmethoxy]-phosphono Amino}-propionic acid isopropyl ester. The CAS registration number is: 1190307-88-0, and the chemical structure is as follows:

Sofosbuvir is a hepatitis C virus (HCV) nucleotide analog NS5B polymerase inhibitor developed by Glead Sciences in the United States. It is suitable for use as a combined component in a combined antiviral therapy or alone It is mainly used for the treatment of adult patients with genotype 1, type 2, type 3 and type 4 chronic hepatitis C (Hepatitis C) in order to block the consistent specific protein required for the replication of hepatitis C virus to treat chronic hepatitis C infection. Sofosbuvir (trade name: Sovaldi, 400mg tablet) was approved by the US Food and Drug Administration (FDA) for marketing in the United States on December 6, 2013, and approved by the European Medicines Agency (EMEA) on January 16, 2014. Approved for marketing in EU countries. Sovaldi is the first drug approved for the full oral treatment of hepatitis C. When used for the treatment of specific genotypes (type 2, type 3) of chronic hepatitis C, it can eliminate the traditional injectable drug interferon (IFN) need. The drug has not yet been launched in the domestic market, and the market prospect is good.

Polymorphic drugs refer to solid drugs whose active ingredients exist in a specific crystal state, and drug polymorphism refers to the existence of two or more different crystal states of a drug. Drug polymorphism is a ubiquitous natural phenomenon in solid pharmaceuticals. Because drugs with different crystal forms may affect their dissolution and absorption in the body, which may affect the clinical efficacy and safety of the drug to a certain extent. Therefore, for polymorphic drugs, when developing solid oral preparations, the study of crystal forms is beneficial to the selection of a meaningful, stable and controllable active ingredient in clinical treatment. For sofosbuvir, polymorphism has been reported, and the original crystal form 6 is the dominant crystal form of the main active ingredient in the marketed finished drug.

Gilead's original research patent CN102858790A discloses 6 crystal forms of sofosbuvir and their preparation methods. US patent US8648076 focuses on the introduction of sofosbuvir crystal form 6 and the protection of the preparation method.

Patent CN102858790A introduces the characteristics of six crystal forms of sofosbuvir, and discloses the corresponding XPRD characterization spectrum and characterization data, and clearly points out that crystal form 1 is composed of crystal form 2, crystal form 3, crystal form 4, and crystal form 5 or transformed from an amorphous form. Crystal form 2, crystal form 3, crystal form 4, and crystal form 5 are obtained by crystallization of amorphous sofosbuvir from different solvents respectively. The preparation of Form 6 requires at least two steps of crystal transformation, that is, Form 2, 3, 4, 5 or amorphous form is transformed into Form 1, and Form 1 is then transformed into Form 6.

Patent US8648076 reports two preparation methods of crystal form 6, both of which are obtained by crystallization from crystal form 1:

Method 1: Since the crystal form 1 is very easy to absorb water and deliquescence, put the powder of the crystal form 1 under indoor humidity, and it will turn into a gel after a few days, grind the gel substance into a powder, and place the powder in the open The sample slowly transformed into Form 6 after being placed in the container for 6-10 weeks.

Method 2: Add crystal form 1 to 5 mg/mL-50 mg/mL water at room temperature, and stir at room temperature or 50°C for more than 40 hours to obtain crystal form 6.

Moreover, patents CN102858790A and US8648076 both specify that crystal form 6 cannot be obtained from organic solvents.

In 2015, Nanjing Qichang Pharmaceutical Technology Co., Ltd. announced the preparation method of sofosbuvir crystallization form 6 through the patent CN104829673A. In this patent, cyclopentyl methyl ether is used as the main crystallization solvent, and ether solvents such as methyl tert-butyl ether, isopropyl ether or dibutyl ether are used in conjunction. However, we repeated the test three times for its Examples 6 and 7 respectively, no matter whether the Sofosbuvir used was an amorphous product or a crystal form 1, crystals could not be separated out, only a group of oily matter was separated out from the organic solvent, and Severe wall sticking.

In addition, according to the literature [J.Med.Chem.2010,53(17),7202-7218] report, in the preparation route of sofosbuvir raw material medicine, pentafluorophenol (II) has influence on the quality of product API as process impurity important impact, therefore, it must be strictly controlled within an appropriate range through the crystallization process to meet the standards of APIs.

In the literature, the method of column chromatography is used to remove the impurity, but the method of column chromatography has defects such as high economic cost and unsuitability for industrial production.

However, the crystal form preparation methods reported in patents CN102858790A and US8648076 do not have a refining effect, and must be purified before preparing the sofosbuvir pharmaceutical crystal form.

To sum up, with the widespread use of sofosbuvir drugs, and to relieve the pain of hepatitis C patients as soon as possible, it is urgent to solve the problem of preparing the sofosbuvir crystal form in patents CN102858790A and US8648076, that is, it must be converted from crystal form 1 It is crystal form 6, and crystal form 1 needs to be obtained from crystal form 2, 3, 4, 5 or amorphous transformation, the steps are cumbersome, there is no refining effect, the raw material drug has high purity requirements, and the cost is high, so it is not suitable for industrial production and other defects.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the preparation of sofosbuvir crystal form 6 in the prior art, which needs to be converted from crystal form 2, 3, 4, 5 or amorphous form to crystal form 1, and then converted from crystal form 1 It is crystal form 6, the steps are cumbersome, the cost is high, and it has no refining effect, it is not easy to meet the standards of raw materials, and it is not suitable for industrial production; and a preparation method of sofosbuvir crystal form 6 is provided. The crystallization process of the preparation method of the present invention is simple and efficient, has few steps, high yield, good repeatability, good purification effect on specific impurities, high purity of the prepared product, can meet the requirements of raw materials, is green and environmentally friendly, and is suitable for industrial production .

The present invention proposes a preparation method of sofosbuvir crystal form 6, which comprises the following steps: the solution formed by sofosbuvir crude product and water-containing alcoholic solvent is mixed with alkane and crystallized to obtain sofosbuvir Wei crystal form 6 is sufficient; the sofosbuvir crude product is a sofosbuvir crude product with a mass content of the specific impurity II not greater than 3%, and the mass content refers to that the mass content of the specific impurity II accounts for sofosbuvir The percentage of crude product mass; the specific impurity II is pentafluorophenol.

In the preparation method of the sofosbuvir crystal form 6, in the "alcohol solvent containing water", the volume ratio of the water to the alcohol solvent is preferably 0.02 to 0.05, such as 0.02, 0.03, 0.04 or 0.05, the volume ratio refers to the ratio of the volume of water to the volume of alcohol solvent.

In the preparation method of the sofosbuvir crystal form 6, in the "alcohol solvent containing water", the "alcohol solvent" is preferably methanol, ethanol, n-propanol, isopropanol, n-propanol, One or more of butanol, tert-butanol and isobutanol; more preferably one or more of ethanol, isopropanol, n-butanol, tert-butanol and isobutanol.

In the preparation method of the sofosbuvir crystal form 6, the volume-to-mass ratio of the "aqueous alcoholic solvent" to the crude sofosbuvir product is preferably 0.5mL/g to 10.0mL/g, further Preferably 2.0 mL/g to 9.0 mL/g, eg 3.1 mL/g, 3.2 mL/L, 4.1 mL/g, 4.2 mL/g or 6.3 mL/g.

In the preparation method of the sofosbuvir crystal form 6, the temperature of the "solution formed by the crude product of sofosbuvir and an aqueous alcoholic solvent" is preferably 5°C to 65°C, more preferably 5°C to 50°C ; For example, 5°C to 10°C, 10°C to 15°C, 20°C to 25°C, 40°C to 45°C or 45°C to 50°C.

In the preparation method of the sofosbuvir crystal form 6, the alkane is preferably one or more of n-heptane, n-hexane, 2-hexane, n-octane and isooctane.

In the preparation method of the sofosbuvir crystal form 6, the volume mass ratio of the alkane to the sofosbuvir crude product is preferably 3.0mL/g-50.0mL/g, more preferably 5.0mL/g-45.0mL/g g, for example 6.0 mL/g, 12.0 mL/L, 13.0 mL/g, 15.0 mL/g, 20.0 mL/g, 22.0 mL/g, 30.0 mL/g or 40.0 mL/g.

In the preparation method of the described sofosbuvir crystal form 6, the sofosbuvir crude product can be sofosbuvir crystal form 1 crude product, sofosbuvir crystal form 2 crude product, sofosbuvir crystal form 3 crude product One or more of the crude product, the crude product of Sofosbuvir crystal form 4, the crude product of Sofosbuvir crystal form 5, and the crude product of Sofosbuvir amorphous form. The sofosbuvir crude product is a sofosbuvir crude product whose mass content of the specific impurity II is not more than 3%; the specific impurity II is pentafluorophenol.

In the preparation method of the sofosbuvir crystal form 6, the method of mixing is preferably dropwise; the speed of the dropwise addition is preferably 1mL/min～100mL/min, more preferably 1mL/min～80mL/min , such as 1.4 mL/min, 2.8 mL/min, 12.6 mL/min, 13.6 mL/min, 51.7 mL/min, 52.0 mL/min, 52.5 mL/min, or 68.7 mL/min.

In the preparation method of the sofosbuvir crystal form 6, the crystallization is preferably carried out under stirring conditions, and the stirring speed is preferably 60 rpm to 500 rpm, more preferably 200 rpm to 260 rpm, such as 200 rpm, 210 rpm, 230 rpm, 250 rpm or 260 rpm.

In the preparation method of the sofosbuvir crystal form 6, the crystallization temperature is preferably 0-50°C, more preferably 10°C-35°C.

In the preparation method of the sofosbuvir crystal form 6, the crystallization time is preferably 10 hours to 96 hours, more preferably 12 hours to 48 hours, such as 15 hours, 16 hours, 24 hours, 34 hours, 36 hours or 44 hours.

In the preparation method of the sofosbuvir crystal form 6, the "solfosbuvir crude product and a water-containing alcoholic solvent" is preferably obtained by the following steps: dissolving the sofosbuvir crude product in a water-containing In the alcoholic solvent, the solution formed by the sofosbuvir crude product and the aqueous alcoholic solvent can be obtained. The dissolution temperature is preferably 5°C to 65°C, more preferably 5°C to 50°C; for example, 5°C to 10°C, 10°C to 15°C, 20°C to 25°C, 40°C to 45°C or 45°C to 50°C ℃.

The preparation method of the sofosbuvir crystal form 6 preferably includes the following post-processing steps: filtering, washing and drying the sofosbuvir crystal form 6 to obtain the purified sofosbuvir crystal form 6.

Described filtration can adopt the conventional method of this kind of operation in this field, adopt filter paper or filter cloth to filter. The filter paper is preferably medium-speed filter paper; the filter cloth is preferably 200-300 mesh filter cloth. The said washing can adopt the conventional method of this type of operation in the art, and the solvent used for washing is preferably a mixed solvent of alcohol solvent and alkane or water. One or more of the preferred methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol and isobutanol of the alcoholic solvent; more preferably ethanol, isopropanol, n-butanol, isobutanol One or more of butanol and tert-butanol. The alkane is preferably one or more of n-heptane, n-hexane, n-octane and isooctane. The "mixed solvent of alcohol solvent and alkane" is preferably a mixed solvent of isopropanol and n-heptane, a mixed solvent of ethanol and n-hexane, a mixed solvent of ethanol and n-heptane, a mixed solvent of n-butanol and n-octane , a mixed solvent of isobutanol and isooctane, a mixed solvent of isopropanol and 2-hexane, a mixed solvent of isobutanol and n-hexane, or a mixed solvent of tert-butanol and n-heptane.

The volume ratio of the alcohol solvent to the alkane described in the "mixed solvent of alcohol solvent and alkane" is preferably 5:1 to 1:5, more preferably 3:1 to 1:3, for example 2: 3. 1:3 or 3:4. The number of times of said washing is preferably 1 to 3 times. Said drying can adopt conventional methods of this type of operation in the art, said drying is preferably vacuum drying; said vacuum drying is preferably carried out in a vacuum oven. The drying temperature is preferably 30°C-70°C, more preferably 45°C-60°C, for example 45°C-50°C. The drying time is preferably 10 hours to 50 hours; more preferably 16 hours to 30 hours, such as 16 hours, 18 hours, 20 hours or 28 hours; the pressure of the vacuum drying is preferably -0.008MPa to -0.1MPa.

The sofosbuvir crystal form 6 prepared by the present invention has a yield greater than 90.0%, an HPLC purity greater than 99.50%, and a maximum single impurity less than 0.10%, reaching the standard of raw materials.

On the basis of not violating common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain preferred examples of the present invention.

The reagents and raw materials used in the present invention are all commercially available.

In the present invention, the room temperature refers to an ambient temperature of 10°C to 35°C.

The positive progress effect of the present invention lies in: the crystallization process of the preparation method of the present invention is simple and efficient, the steps are short, the yield is high, the repeatability is good, the refining effect on the specific impurity II is obvious, the obtained product has good stability and high purity, and is suitable for use as The requirements of oral solid preparations meet the requirements of raw materials (HPLC purity greater than 99.50%, the largest single impurity less than 0.1%), green and environmentally friendly, suitable for industrial production.

Description of drawings

Fig. 1 is the XRD spectrogram of sofosbuvir obtained according to embodiment 1 of the present invention.

Fig. 2 is the XPRD spectrogram of sofosbuvir obtained according to Example 1 of the present invention.

Fig. 3 is the DSC spectrogram of sofosbuvir obtained according to Example 1 of the present invention.

Fig. 4 is the TGA spectrogram of sofosbuvir obtained according to Example 1 of the present invention.

Fig. 5 is the XPRD spectrogram of sofosbuvir obtained according to Example 2 of the present invention.

Figure 6 is the XPRD spectrum of sofosbuvir obtained according to Example 3 of the present invention.

detailed description

The present invention is further illustrated below by means of examples, but the present invention is not limited to the scope of the examples. For the experimental methods that do not specify specific conditions in the following examples, select according to conventional methods and conditions, or according to the product instructions.

In the preparation process of sofosbuvir crystal form 6 of the present invention, the sofosbuvir crude product used (including sofosbuvir amorphous form, crystal form 1, crystal form 2, crystal form 3, crystal form 4 and crystal form 5, etc.) all prepare sofosbuvir products according to existing literature reports (such as: J.Med.Chem.2010,53 (17), 7202-7218), and other solvents and reagents are commercially available chemically pure or analytical pure.

Example 1

10 ℃～15 ℃, sofosbuvir crystal form 1 crude product (5.0g, HPLC purity 97.3%, specific impurity II mass content is 2.4%; described mass content refers to the mass content of specific impurity II in a single-necked flask The percentage of sofosbuvir crude product mass; The specific impurity II is that pentafluorophenol is completely dissolved in isopropanol (20mL), and water (0.6mL, water: isopropanol volume ratio is 0.03) is added to obtain sofosbuvir The solution formed by the crude product of Sofosbuvir and isopropanol containing water, and then the solution formed by the crude product of sofosbuvir and isopropanol containing water is transferred to a constant pressure dropping funnel for subsequent use.

Add n-heptane (30mL) into a three-necked flask equipped with mechanical stirring, turn on the mechanical stirring, and the stirring speed is 260 rpm. The solution formed by the alcohol is slowly dropped into the n-heptane solution through a constant pressure dropping funnel, which takes about 15 minutes, and a milky white suspension can be obtained after the drop is completed. Continue stirring at room temperature (10°C to 35°C) for 15 hours to crystallize, filter with medium-speed filter paper, and rinse the filter cake with 10 mL of a mixed solvent of isopropanol and n-heptane (volume ratio of isopropanol: n-heptane is 2:3). After washing once, vacuum drying at 45°C to 50°C for 16 hours (vacuum degree-0.008MPa), 4.74g of Sofosbuvir product was obtained, with a yield of 94.8%, HPLC purity of 99.74%, and the largest single impurity (impurity II) 0.04%.

The mother liquor is left to stand for 5 days, sofosbuvir single crystal can be separated out, and the single crystal pattern (XRD) is shown in Figure 1. After the crystal is separated, the Bruker SMART APEX-II diffractometer is used to collect diffraction intensity data, CuKa radiation, graphite Monochromator, single tube diameter Ψ=0.50mm, distance between crystal and CCD detector d=60.3mm, tube pressure 40KV, tube current 30mA, scanning method: ψ/ω scanning, total number of collected diffraction points is 9575, independent diffraction points The number of observable points is 4822, and the number of observable points is 4778. The measurement results are: the crystal is colorless and transparent columnar, the crystal size for diffraction experiment is 0.15×0.18×0.26mm, it belongs to monoclinic system, space group P2 ₁ , unit cell parameters : a=12.956(3), b=6.2049(12), α=γ=90.0°, β=93.87(3)°, unit cell volume The number of asymmetric units in the unit cell is Z=2.

The crystal product obtained by drying is subjected to powder X-ray diffraction (XPRD) detection, and its spectrum is shown in FIG. 2 . The powder X-ray diffraction data of Sofosbuvir Form 6 corresponding to Figure 2 are shown in Table 1. The DSC spectrum of sofosbuvir obtained in Example 1 is shown in Figure 3. The endothermic transition of sofosbuvir crystal form 6 is at 126.0°C±2°C, and the melting absorption heat peak is 100.7J/g. The TGA spectrum of sofosbuvir obtained in Example 1 is shown in Figure 4, and the TGA weight loss is 0.36%.

The XPRD characteristic peak position of table 1 embodiment 1 gained sofosbuvir products

The result shown in the XPRD spectrum is consistent with the characteristic spectrum of the original crystal form 6 reported in patents CN102858790A and US8648076, and it can be confirmed that the crystal is sofosbuvir crystal form 6.

Example 2

5 ℃ ~ 10 ℃, sofosbuvir crystal form 1 crude product (1.0kg, HPLC purity 98.3%, specific impurity II mass content 2.1%) was completely dissolved in ethanol (3L) in a single-necked flask, then added water (100mL ) to obtain the solution formed by the crude product of Sofosbuvir and ethanol containing water, then transfer the solution formed by the crude product of Sofosbuvir and ethanol containing water into the constant pressure dropping funnel for subsequent use.

Add n-hexane (20L) to the reactor equipped with mechanical stirring, turn on the mechanical stirring, the rotation speed is 230 rpm, at room temperature (10 ° C ~ 35 ° C), the solution formed by the crude product of sofosbuvir and ethanol containing water Slowly drop it into the n-hexane solution through a constant pressure dropping funnel, which takes about 60 minutes, and a milky white suspension can be obtained after the drop is completed. Continue stirring at room temperature (10°C-35°C) for 44 hours to crystallize, filter with a 200-mesh-300-mesh filter cloth, rinse the filter cake once with 1L of ethanol and n-hexane mixed solvent (volume ratio of ethanol:n-hexane is 1:3) , 45 ℃ ~ 50 ℃ vacuum drying for 20 hours (vacuum degree -0.008MPa), sofosbuvir product 936g, yield 93.6%, HPLC purity 99.77%, the largest single impurity (impurity II) 0.03%.

The crystal product obtained by drying is subjected to powder X-ray diffraction (PXRD) detection, and its spectrogram is as shown in Figure 5, and the powder X-ray diffraction data of Sofosbuvir crystal form 6 corresponding to Figure 5 are shown in Table 2 . After analysis, the test results of the product are consistent with the characteristic spectrum of the original sofosbuvir crystal form 6 reported in the patent, confirming that the product is sofosbuvir crystal form 6.

The XPRD characteristic peak position table of table 2 embodiment 2 gained Sofosbuvir products

The result shown in the XPRD spectrum is consistent with the characteristic spectrum of the original crystal form 6 reported in patents CN102858790A and US8648076, and it can be confirmed that the crystal is sofosbuvir crystal form 6.

Example 3

At 40°C to 45°C, the sofosbuvir crystal form 3 crude product (100g, HPLC purity 97.1%, specific impurity II mass content 2.8%) was completely dissolved in n-butanol (600mL) in a single-necked flask, and water was added (30mL) to obtain the solution that sofosbuvir crude product and aqueous n-butanol form, then the solution that sofosbuvir crude product and aqueous n-butanol form is transferred in the constant pressure dropping funnel, for subsequent use.

Add n-octane (3L) to the reactor equipped with mechanical stirring, turn on the mechanical stirring, the rotating speed is 200 rpm, at room temperature (10 ° C ~ 35 ° C), mix the crude product of sofosbuvir with aqueous n-butanol The formed solution was slowly dropped into the n-octane solution through a constant-pressure dropping funnel, which took about 50 minutes, and a milky white suspension was obtained after the dropping. Continue stirring at room temperature (10°C to 35°C) for 36 hours to crystallize, filter with a 200-mesh to 300-mesh filter cloth, and use 300 mL of n-butanol and n-octane mixed solvent for the filter cake (n-butanol: n-octane volume ratio is 3: 4) Rinse once, vacuum dry at 45°C-50°C for 28 hours, vacuum degree -0.008MPa, obtain 96.2g of Sofosbuvir product, yield: 96.2%, HPLC purity 99.87%, largest single impurity 0.03%.

The crystal product obtained by drying is subjected to powder X-ray diffraction (XPRD) detection, and its spectrogram is shown in Figure 6, and the powder X-ray diffraction data of Sofosbuvir crystal form 6 corresponding to Figure 6 are shown in Table 3 . After analysis, the test results of the product are consistent with the characteristic spectrum of the original sofosbuvir crystal form 6 reported in the patent, confirming that the product is sofosbuvir crystal form 6.

The XPRD characteristic peak position of table 3 embodiment 3 gained sofosbuvir products

The result shown in the XPRD spectrum is consistent with the characteristic spectrum of the original crystal form 6 reported in patents CN102858790A and US8648076, and it can be confirmed that the crystal is sofosbuvir crystal form 6.

Example 4

At 45°C to 50°C, the sofosbuvir crystal form 4 crude product (100g, HPLC purity 97.1%, specific impurity II mass content 2.8%) was completely dissolved in tert-butanol (400mL) in a single-necked flask, and water ( 8mL) to obtain the solution that sofosbuvir crude product and water-containing tert-butanol form, then the solution that this sofosbuvir crude product and water-containing tert-butanol form is transferred in the constant pressure dropping funnel, for subsequent use.

Add n-heptane (1.3 L) to the reactor equipped with mechanical stirring, turn on the mechanical stirring, the rotating speed is 200 rpm, at room temperature (10 ° C ~ 35 ° C), mix the crude product of sofosbuvir with water-containing tert-butyl The solution formed by the alcohol is slowly dropped into the n-heptane solution through a constant pressure dropping funnel, which takes about 30 minutes, and a milky white suspension can be obtained after the drop is completed. Continue to stir at room temperature (10°C-35°C) for 15 hours to crystallize, filter with 200-300-mesh filter cloth, rinse the filter cake with water (100mL) once, and vacuum-dry at 45°C-50°C for 18 hours (vacuum degree -0.008MPa ), sofosbuvir product 95.7g, yield 95.7%, HPLC purity 99.73%, the largest single impurity 0.04%.

The crystalline product obtained by drying is subjected to powder X-ray diffraction (XPRD) detection. After analysis, the test result of the product is consistent with the characteristic spectrum of the original crystal form 6 of sofosbuvir reported in the patent (the original crystal form reported in patent CN102858790A and US8648076 6), confirming that the product is sofosbuvir crystal form 6.

Example 5

At 20°C to 25°C, the sofosbuvir crystal form 5 crude product (10g, HPLC purity 97.1%, specific impurity II mass content 2.8%) was completely dissolved in isobutanol (40mL) in a single-necked flask, and water ( 2mL) to obtain the solution formed by the crude product of sofosbuvir and isobutanol containing water, then the solution formed by the crude product of sofosbuvir and isobutanol containing water is transferred to a constant pressure dropping funnel for subsequent use.

Add isooctane (400mL) to the reactor equipped with mechanical stirring, turn on the mechanical stirring, the rotating speed is 210 rpm, at room temperature (10°C～35°C), mix the crude product of sofosbuvir with aqueous isobutanol The formed solution was slowly dropped into the isooctane solution through a constant pressure dropping funnel, which took about 15 minutes, and a milky white suspension was obtained after the drop was completed. Continue stirring at room temperature (10°C to 35°C) for 16 hours to crystallize, filter with a 200-mesh to 300-mesh filter cloth, and use 10 mL of a mixed solvent of isobutanol and isooctane for the filter cake (the volume ratio of isobutanol: isooctane is 3: 4) Rinse once, and vacuum dry at 45°C-50°C for 28 hours (vacuum degree-0.008MPa), to obtain 9.2g of Sofosbuvir product, with a yield of 92%, HPLC purity of 99.73%, and the largest single impurity of 0.06%.

The crystalline product obtained by drying is subjected to powder X-ray diffraction (XPRD) detection. After analysis, the test result of the product is consistent with the characteristic spectrum of the original crystal form 6 of sofosbuvir reported in the patent (the original crystal form reported in patent CN102858790A and US8648076 6), confirming that the product is sofosbuvir crystal form 6.

Example 6

5 ℃～10 ℃, sofosbuvir amorphous crude product (1.0kg, HPLC purity 97.1%, specific impurity II mass content 2.8%) was completely dissolved in isopropanol (3L) in a single-necked flask, added water (150mL ) to obtain the solution formed by the sofosbuvir crude product and aqueous isopropanol, then transfer the solution formed by the sofosbuvir crude product and aqueous isopropanol into a constant pressure dropping funnel for subsequent use.

Add 2-hexane (15L) into the reactor equipped with mechanical stirring, turn on the mechanical stirring, the rotation speed is 230 rpm, at room temperature (10°C ~ 35°C), mix the crude product of sofosbuvir with aqueous isopropyl The solution formed by the alcohol is slowly dropped into the aqueous solution through a constant pressure dropping funnel, which takes about 60 minutes, and a milky white suspension can be obtained after the drop is completed. Continue stirring at room temperature (10°C to 35°C) for 24 hours to crystallize, filter with a 200-mesh to 300-mesh filter cloth, and use 500 mL of isopropanol and 2-hexane mixed solvent for the filter cake (volume of isopropanol: 2-hexane mixed solvent The ratio is 3:4), rinse once, and vacuum dry at 45°C to 50°C for 20 hours (vacuum degree-0.008MPa), to obtain 935g of Sofosbuvir product, with a yield of 93.5%, HPLC purity of 99.65%, and the largest single impurity of 0.05%. .

The crystalline product obtained by drying is subjected to powder X-ray diffraction (XPRD) detection. After analysis, the test result of the product is consistent with the characteristic spectrum of the original crystal form 6 of sofosbuvir reported in the patent (the original crystal form reported in patent CN102858790A and US8648076 6), confirming that the product is sofosbuvir crystal form 6.

Example 7

5°C to 10°C, in a single-necked flask, completely dissolve the crude product of Sofosbuvir Form 2 (1.0kg, HPLC purity 97.1%, specific impurity II mass content 2.8%) in ethanol (3L), add water (90mL) Obtain the solution formed by the crude product of Sofosbuvir and ethanol containing water, and then transfer the solution formed by the crude product of Sofosbuvir and ethanol containing water into a constant pressure dropping funnel for subsequent use.

Add n-heptane (20L) into the reactor equipped with mechanical stirring, turn on the mechanical stirring, the rotating speed is 230 rpm, at room temperature (10 ° C ~ 35 ° C), the sofosbuvir crude product and the ethanol containing water are formed The solution was slowly dropped into the n-heptane solution through a constant pressure dropping funnel, which took about 60 minutes, and a milky white suspension was obtained after the drop. Continue stirring at room temperature (10°C-35°C) for 24 hours to crystallize, filter with a 200-mesh-300-mesh filter cloth, rinse the filter cake with 3L of ethanol and n-heptane mixed solvent (volume ratio of ethanol:n-heptane is 1:3) Once, vacuum drying at 45°C-50°C for 20 hours (vacuum degree-0.008MPa), 956g of sofosbuvir product was obtained, with a yield of 95.6%, HPLC purity of 99.75%, and the largest single impurity of 0.06%.

The crystalline product obtained by drying is subjected to powder X-ray diffraction (XPRD) detection. After analysis, the test result of the product is consistent with the characteristic spectrum of the original crystal form 6 of sofosbuvir reported in the patent (the original crystal form reported in patent CN102858790A and US8648076 6), confirming that the product is sofosbuvir crystal form 6.

Example 8

5°C to 10°C, in a single-necked flask, the sofosbuvir crystal form 3 crude product (1.0kg, HPLC purity 97.1%, specific impurity II mass content 2.8%) was completely dissolved in isobutanol (3L), and water ( 120mL) to obtain the solution that sofosbuvir crude product and aqueous isobutanol form, then the solution that this sofosbuvir crude product and aqueous isobutanol forms is transferred in the constant pressure dropping funnel, for subsequent use.

Add n-hexane (22L) into the reactor equipped with mechanical stirring, turn on the mechanical stirring, the rotating speed is 230 rpm, at room temperature (10°C-35°C), the sofosbuvir crude product is formed with aqueous isobutanol The solution was slowly dropped into the n-hexane solution through a constant pressure dropping funnel, which took about 60 minutes, and a milky white suspension was obtained after the drop. Continue to stir at room temperature (10°C-35°C) for 34 hours to crystallize, filter with a 200-300-mesh filter cloth, and use 1 L of isobutanol and n-hexane mixed solvent for the filter cake (the volume ratio of isobutanol:n-hexane is 2:3) Rinse once, and vacuum dry at 45°C-50°C for 20 hours (vacuum degree-0.008MPa), to obtain 913g of Sofosbuvir product with a yield of 91.3%, HPLC purity of 99.57%, and the largest single impurity of 0.09%.

The crystalline product obtained by drying is subjected to powder X-ray diffraction (PXRD) detection. After analysis, the test result of the product is consistent with the characteristic spectrum of the original crystal form 6 of sofosbuvir reported in the patent (the original crystal form reported in patent CN102858790A and US8648076 6), confirming that the product is sofosbuvir crystal form 6.

Example 9

5 ℃～10 ℃, sofosbuvir amorphous crude product (1.0kg, HPLC purity 97.1%, specific impurity II mass content 2.8%) was completely dissolved in tert-butanol (4L) in a single-necked flask, and water (120mL ) to obtain the solution formed by the sofosbuvir crude product and water-containing tert-butanol, and then transfer the solution formed by the sofosbuvir crude product and water-containing tert-butanol into a constant-pressure dropping funnel for subsequent use.

Add n-heptane (12L) into the reactor equipped with mechanical stirring, turn on the mechanical stirring, the rotating speed is 250 rpm, at room temperature (10°C～35°C), mix the crude product of sofosbuvir with water-containing tert-butanol The formed solution was slowly dropped into the n-heptane solution through a constant pressure dropping funnel, which took about 60 minutes, and a milky white suspension was obtained after the dropping. Continue to stir at room temperature (10°C-35°C) for 24 hours to crystallize, filter with a 200-300-mesh filter cloth, and use 1L of mixed solvent of tert-butanol and n-heptane for the filter cake (the volume ratio of tert-butanol: n-heptane is 2: 3) Rinse once, and vacuum dry at 45°C-50°C for 20 hours (vacuum degree-0.008MPa), to obtain 917g of Sofosbuvir product, with a yield of 91.7%, HPLC purity of 99.63%, and the largest single impurity of 0.08%.

The crystalline product obtained by drying is subjected to powder X-ray diffraction (PXRD) detection. After analysis, the test result of the product is consistent with the characteristic spectrum of the original crystal form 6 of sofosbuvir reported in the patent (the original crystal form reported in patent CN102858790A and US8648076 6), confirming that the product is sofosbuvir crystal form 6.

Comparative Example 1 (with reference to patent CN 102858790, the operation of paragraph 0459)

Using the same starting material sofosbuvir (crystalline form 1, 1.04 g) as in the crystallization process of Example 2, was added to 40 mL of water, magnetically stirred and heated to 50° C. And vigorously stirred at 50°C for 1 hour, then added Sofosbuvir crystal form 6 (0.1g) as a seed crystal, cooled to 20°C within 90 minutes, kept stirring for 16 hours, a large amount of white solids were precipitated, and adhered to bottle wall. Then cool down to 0-5°C within 30 minutes and keep it warm for 2.5 hours, filter the crystallization mixture to get the filter cake, wash it with 10mL of ice-cold water, and dry the filter cake in vacuum at a vacuum degree of -0.008MPa, and dry at 45°C-50°C for 50 hours 0.76g of Sofosbuvir product was obtained, yield: 76%, HPLC purity 99.33%, maximum single 0.25%.

Conclusion: the yield is greatly reduced compared with Example 2. During the crystal transformation reaction, a large amount of white solids adhere to the wall of the kettle. During industrial production, it is difficult to take out the product adhered to the wall of the reactor, which is not suitable for industrial production. Moreover, the HPLC purity of the product obtained by the crystallization reaction is only 99.33%, and the maximum simple impurity reaches 0.25%; it does not reach the raw material drug standard of HPLC purity>99.5%, and the maximum simple impurity is less than 0.1%.

Comparative Example 2: (with reference to the operating steps of Patent CN104829673A Example 1, no crystals were precipitated)

Use the same starting material Sofosbuvir (crystalline form 1, 5g) as in the crystallization process of Example 2, add to the mixed solution containing 50mL cyclopentyl methyl ether and 5mL anisole, and heat the mixture to 75°C , and with stirring at 20 rpm the solids were completely dissolved, which took about 15 minutes. Then it was cooled to 20-25° C. within 90 minutes, and sofosbuvir Form 6 white powder (0.1 g) was added as a seed crystal. Stirring at this temperature at a speed of 30 rpm for 16 hours, and then cooling down to 0°C for 1 hour, no crystals precipitated.

Claims (10)

1. a preparation method of Sofosbuvir crystal form 6, is characterized in that it comprises the following steps: the solution that Sofosbuvir crude product and the alcoholic solvent containing water are formed, mixes with alkane again, crystallizes, obtains Sofosbuvir Buwei crystal form 6 is sufficient; the sofosbuvir crude product is a sofosbuvir crude product with a mass content of the specific impurity II not greater than 3%, and the mass content refers to that the mass content of the specific impurity II accounts for sofosbuvir The percentage of Wei crude product quality; Described specific impurity II is pentafluorophenol. 2. the preparation method of sofosbuvir crystal form 6 as claimed in claim 1, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, in the "alcohol solvent containing water", the volume ratio of the water to the alcohol solvent is 0.02-0.05, and the Volume ratio refers to the ratio of the volume of water to the volume of alcoholic solvent; and / or, In the preparation method of the described sofosbuvir crystal form 6, in the "alcohol solvent containing water", the "alcohol solvent" is methanol, ethanol, n-propanol, isopropanol, n-propanol, One or more of butanol, tert-butanol and isobutanol; and / or, In the preparation method of the sofosbuvir crystal form 6, the volume-to-mass ratio of the "aqueous alcoholic solvent" to the crude sofosbuvir product is 0.5mL/g-10.0mL/g; and / or, In the preparation method of the sofosbuvir crystal form 6, the temperature of the "solution formed by the crude sofosbuvir product and the aqueous alcoholic solvent" is 5°C to 65°C; and / or, In the preparation method of the sofosbuvir crystal form 6, the alkane is one or more of n-heptane, n-hexane, 2-hexane, n-octane and isooctane; and / or, In the preparation method of the sofosbuvir crystal form 6, the volume mass ratio of the alkane to the sofosbuvir crude product is 3.0mL/g～50.0mL/g; and / or, In the preparation method of the sofosbuvir crystal form 6, the sofosbuvir crude product is the sofosbuvir crystal form 1 crude product, the sofosbuvir crystal form 2 crude product, and the sofosbuvir crystal form 3 crude product , one or more of the crude product of Sofosbuvir crystal form 4, the crude product of Sofosbuvir crystal form 5, and the crude product of Sofosbuvir amorphous form. 3. the preparation method of sofosbuvir crystal form 6 as claimed in claim 2, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, in the "alcohol solvent containing water", the volume ratio of the water to the alcohol solvent is 0.02, 0.03, 0.04 or 0.05 ; and / or, In the preparation method of the described sofosbuvir crystal form 6, in the "alcohol solvent containing water", the "alcohol solvent" is ethanol, isopropanol, n-butanol, tert-butanol and One or more of isobutanol; and / or, In the preparation method of the sofosbuvir crystal form 6, the volume-mass ratio of the "aqueous alcoholic solvent" to the crude sofosbuvir product is 2.0mL/g-9.0mL/g; and / or, In the preparation method of the sofosbuvir crystal form 6, the temperature of the "solution formed by the crude sofosbuvir product and the aqueous alcoholic solvent" is 5°C to 50°C; and / or, In the preparation method of the sofosbuvir crystal form 6, the volume-mass ratio of the alkane to the crude sofosbuvir product is 5.0mL/g-45.0mL/g. 4. the preparation method of sofosbuvir crystal form 6 as claimed in claim 3, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, the volume mass ratio of the "aqueous alcoholic solvent" to the crude sofosbuvir product is 3.1mL/g, 3.2mL/L, 4.1 mL/g, 4.2mL/g or 6.3mL/g; and / or, In the preparation method of the sofosbuvir crystal form 6, the temperature of the "solution formed by the crude product of sofosbuvir and an alcoholic solvent containing water" is 5°C to 10°C, 10°C to 15°C, 20°C ℃～25℃, 40℃～45℃ or 45℃～50℃; and / or, In the preparation method of the sofosbuvir crystal form 6, the volume mass ratio of the alkane to the sofosbuvir crude product is 6.0mL/g, 12.0mL/L, 13.0mL/g, 15.0mL/g, 20.0 mL/g, 22.0 mL/g, 30.0 mL/g, or 40.0 mL/g. 5. the preparation method of sofosbuvir crystal form 6 as claimed in claim 1, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, the mixing method is dropwise; and / or, In the preparation method of the sofosbuvir crystal form 6, the crystallization is carried out under stirring conditions; and / or, In the preparation method of the sofosbuvir crystal form 6, the temperature of the crystallization is 0-50°C; and / or, In the preparation method of the sofosbuvir crystal form 6, the crystallization time is 10 hours to 96 hours. 6. The preparation method of Sofosbuvir crystal form 6 as claimed in claim 5, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, when mixing by dropwise addition, the rate of the dropwise addition is 1mL/min～100mL/min; and / or, In the preparation method of the sofosbuvir crystal form 6, when the crystallization is carried out under stirring conditions, the stirring speed is 60 rpm to 500 rpm; and / or, In the preparation method of the sofosbuvir crystal form 6, the crystallization temperature is 10°C to 35°C; and / or, In the preparation method of the sofosbuvir crystal form 6, the crystallization time is 12 hours to 48 hours. 7. The preparation method of Sofosbuvir crystal form 6 as claimed in claim 6, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, when mixing by dropwise addition, the rate of the dropwise addition is 1mL/min～80mL/min; and / or, In the preparation method of the sofosbuvir crystal form 6, when the crystallization is carried out under stirring conditions, the stirring speed is 200 rpm to 260 rpm; and / or, In the preparation method of the sofosbuvir crystal form 6, the crystallization time is 15 hours, 16 hours, 24 hours, 34 hours, 36 hours or 44 hours. 8. The preparation method of Sofosbuvir crystal form 6 as claimed in claim 1, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, the "solution formed by the sofosbuvir crude product and the aqueous alcoholic solvent" is obtained by the following steps: dissolving the sofosbuvir crude product in the aqueous alcoholic solvent In the solvent-like solvent, the solution formed by the sofosbuvir crude product and the alcoholic solvent containing water can be obtained; and / or, The preparation method of the sofosbuvir crystal form 6 includes the following post-processing steps: filtering, washing and drying the sofosbuvir crystal form 6 to obtain the purified sofosbuvir crystal form 6. 9. The preparation method of Sofosbuvir crystal form 6 as claimed in claim 8, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, in the step adopted in the "solution formed by the crude product of sofosbuvir and an aqueous alcoholic solvent", the temperature of the dissolution is 5° C. to 65° C. ℃; and / or, In the post-processing step included in the preparation method of the sofosbuvir crystal form 6, the filter is filtered with filter paper or filter cloth; and / or, In the post-processing step included in the preparation method of the sofosbuvir crystal form 6, the solvent used in the washing is a mixed solvent of an alcohol solvent and an alkane or water; and / or, In the post-processing step included in the preparation method of the sofosbuvir crystal form 6, the number of washings is 1 to 3 times; and / or, In the post-processing step included in the preparation method of the sofosbuvir crystal form 6, the drying is vacuum drying; and / or, In the post-treatment step included in the preparation method of the sofosbuvir crystal form 6, the drying temperature is 30°C to 70°C; and / or, In the post-treatment step included in the preparation method of the sofosbuvir crystal form 6, the drying time is 10 hours to 50 hours. 10. The preparation method of Sofosbuvir crystal form 6 as claimed in claim 9, is characterized in that: In the preparation method of the sofosbuvir crystal form 6, in the step adopted in the "solution formed by the crude sofosbuvir product and the aqueous alcoholic solvent", the dissolution temperature is 5°C to 50°C ℃; and / or, In the post-processing step included in the preparation method of the sofosbuvir crystal form 6, when filter paper is used for filtration, the filter paper is medium-speed filter paper; and / or, In the post-processing step included in the preparation method of the sofosbuvir crystal form 6, when filter cloth is used for filtering, the filter cloth is a filter cloth of 200 mesh to 300 mesh; and / or, In the post-processing step included in the preparation method of the sofosbuvir crystal form 6, when the solvent used in the washing is a mixed solvent of an alcohol solvent and an alkane, the alcohol solvent is methanol, ethanol, One or more of n-propanol, isopropanol, n-butanol, tert-butanol and isobutanol; and / or, In the post-processing step included in the preparation method of the sofosbuvir crystal form 6, when the solvent used in the washing is a mixed solvent of an alcohol solvent and an alkane, the alkane is n-heptane, n-hexane One or more of , n-octane and isooctane; and / or, In the post-treatment step included in the preparation method of the sofosbuvir crystal form 6, when the solvent used in the washing is a mixed solvent of alcohol solvent and alkane, the "mixture of alcohol solvent and alkane The volume ratio of the alcohol solvent described in "Solvent" to the alkane is 5:1～1:5; and / or, In the post-processing step included in the preparation method of sofosbuvir crystal form 6, when the drying is vacuum drying, the vacuum drying is carried out in a vacuum drying oven; and / or, In the post-treatment step included in the preparation method of the sofosbuvir crystal form 6, the drying temperature is 45°C to 60°C; and / or, In the post-treatment step included in the preparation method of the sofosbuvir crystal form 6, the drying time is 16 hours to 30 hours.