A crystal form of a nucleoside compound, and preparation method and application thereof

Abstract

The present application relates to a crystal form of a compound of formula (I) and a preparation method and application thereof. Specifically, the present application provides a crystal form of a compound of formula (I), which has good stability, good drug efficacy, and good safety, and can be used for preparing a drug for treating or preventing feline transmissible enteric disease virus infection or coronavirus infection caused diseases.

Description

Technical Field

[0001] This invention relates to the field of medicinal chemistry, and in particular to a crystal form of a nucleoside compound, its preparation method, and its application. Background Technology

[0002] Feline coronaviruses are enveloped, non-segmented, single-stranded, positive-sense RNA viruses. Feline enteric coronaviruses are the most common, prevalent in cats worldwide with a carrier rate of 70%–80%. While not a serious pathogen in itself, approximately 5% of persistently infected cats develop highly lethal mutant feline infectious peritonitis virus (FIPV), causing FIP. The compound of formula (I) of this invention has been proven to be effective against FIP; however, prior art lacks research on the relevant crystal forms of compound (I). Therefore, there is an urgent need to find a suitable crystal form for compound (I) that is easy to store, has long-term product stability, and high bioavailability.

[0003] Summary of the Invention

[0004] One aspect of the present invention is to provide a crystal form I of a compound of formula (I), the structure of which is shown below:

[0005]

[0006] In some embodiments, the X-ray powder diffraction pattern of crystal form I of the compound of formula (I) has a diffraction peak at 4.0 ± 0.2°; or at 7.0 ± 0.2°; or at 10.5 ± 0.2°; or at 10.7 ± 0.2°; or at 12.0 ± 0.2°; or at 12.2 ± 0.2°; or at 13.8 ± 0.2°; or at 14.0 ± 0.2°; or at 14.4 ± 0.2°; or at 16.1 ± 0.2°; or The diffraction peaks are located at 16.6±0.2°; or at 17.5±0.2°; or at 19.3±0.2°; or at 20.1±0.2°; or at 20.5±0.2°; or at 20.8±0.2°; or at 21.2±0.2°; or at 25.7±0.2°; preferably including any 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 of the above diffraction peaks, more preferably including any 6, 12 or 18 of them.

[0007] In some embodiments, the X-ray powder diffraction pattern of crystal form I of the compound of formula (I) has diffraction peaks at 4.0±0.2°, 7.0±0.2°, 10.5±0.2°, 10.7±0.2°, 13.8±0.2°, and 14.0±0.2°;

[0008] In some embodiments, the X-ray powder diffraction pattern of crystal form I of the compound of formula (I) has diffraction peaks at 4.0±0.2°, 7.0±0.2°, 10.5±0.2°, 10.7±0.2°, 12.0±0.2°, 12.2±0.2°, 13.8±0.2°, 14.0±0.2°, 14.4±0.2°, 17.5±0.2°, 20.1±0.2°, and 25.7±0.2°.

[0009] In some embodiments, the X-ray powder diffraction pattern of crystal form I of the compound of formula (I) has diffraction peaks at 4.0±0.2°, 7.0±0.2°, 10.5±0.2°, 10.7±0.2°, 12.0±0.2°, 12.2±0.2°, 13.8±0.2°, 14.0±0.2°, 14.4±0.2°, 16.1±0.2°, 16.6±0.2°, 17.5±0.2°, 19.3±0.2°, 20.1±0.2°, 20.5±0.2°, 20.8±0.2°, 21.2±0.2°, and 25.7±0.2°.

[0010] In some embodiments, the crystal form I of the compound of formula (I) has substantially the following characteristics: Figure 1 The X-ray powder diffraction pattern shown is basically as follows: Figure 2 As shown.

[0011] Another aspect of the present invention is to provide a crystal form II of a compound of formula (I), the structure of which is as shown above.

[0012] In some embodiments, the X-ray powder diffraction pattern of crystal form II of the compound of formula (I) has a diffraction peak at 4.0 ± 0.2°; or at 6.9 ± 0.2°; or at 10.6 ± 0.2°; or at 12.0 ± 0.2°; or at 13.9 ± 0.2°; or at 14.4 ± 0.2°; or at 16.1 ± 0.2°; or at 16.5 ± 0.2°; or at 17.5 ± 0.2°; or at 18.8 ± 0.2°. Alternatively, it may have a diffraction peak at 19.2±0.2°; or at 20.2±0.2°; or at 21.0±0.2°; or at 22.4±0.2°; or at 25.7±0.2°; or at 26.6±0.2°; or at 27.6±0.2°; or at 28.1±0.2°; preferably including any 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18 of the above diffraction peaks, more preferably including any 6, 12 or 18 of them.

[0013] In some embodiments, the X-ray powder diffraction pattern of crystal form II of the compound of formula (I) has diffraction peaks at 4.0±0.2°, 6.9±0.2°, 10.6±0.2°, 12.0±0.2°, 13.9±0.2°, and 25.7±0.2°;

[0014] In some embodiments, the X-ray powder diffraction pattern of crystal form II of the compound of formula (I) has diffraction peaks at 4.0±0.2°, 6.9±0.2°, 10.6±0.2°, 12.0±0.2°, 13.9±0.2°, 14.4±0.2°, 16.1±0.2°, 16.5±0.2°, 17.5±0.2°, 19.2±0.2°, 20.2±0.2°, and 25.7±0.2°.

[0015] In some embodiments, the X-ray powder diffraction pattern of crystal form II of the compound of formula (I) has diffraction peaks at 4.0±0.2°, 6.9±0.2°, 10.6±0.2°, 12.0±0.2°, 13.9±0.2°, 14.4±0.2°, 16.1±0.2°, 16.5±0.2°, 17.5±0.2°, 18.8±0.2°, 19.2±0.2°, 20.2±0.2°, 21.0±0.2°, 22.4±0.2°, 25.7±0.2°, 26.6±0.2°, 27.6±0.2°, and 28.1±0.2°.

[0016] In some embodiments, the crystal form II of the compound of formula (I) has substantially the following characteristics: Figure 3 The X-ray powder diffraction pattern shown is basically as follows: Figure 4 As shown.

[0017] Another aspect of the present invention is to provide a crystal form III of a compound of formula (I), the structure of which is as shown above.

[0018] In some embodiments, the X-ray powder diffraction pattern of crystal form III of the compound of formula (I) has a diffraction peak at 5.1 ± 0.2°; or at 6.5 ± 0.2°; or at 8.8 ± 0.2°; or at 10.3 ± 0.2°; or at 11.5 ± 0.2°; or at 11.8 ± 0.2°; or at 13.9 ± 0.2°; or at 14.0 ± 0.2°; or at 15... The diffraction peak is present at 0.5 ± 0.2°; or at 16.1 ± 0.2°; or at 16.4 ± 0.2°; or at 17.4 ± 0.2°; or at 18.4 ± 0.2°; or at 19.7 ± 0.2°; or at 19.9 ± 0.2°; preferably including any 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 of the above diffraction peaks, more preferably including any 6, 11 or 15 of them.

[0019] In some embodiments, the X-ray powder diffraction pattern of crystal form III of the compound of formula (I) has diffraction peaks at 5.1±0.2°, 6.5±0.2°, 11.5±0.2°, 11.8±0.2°, 15.5±0.2°, and 17.4±0.2°;

[0020] In some embodiments, the X-ray powder diffraction pattern of crystal form III of the compound of formula (I) has diffraction peaks at 5.1±0.2°, 6.5±0.2°, 11.5±0.2°, 11.8±0.2°, 13.9±0.2°, 14.0±0.2°, 15.5±0.2°, 16.1±0.2°, 17.4±0.2°, 18.4±0.2°, and 19.9±0.2°.

[0021] In some embodiments, the X-ray powder diffraction pattern of crystal form III of the compound of formula (I) has diffraction peaks at 5.1±0.2°, 6.5±0.2°, 8.8±0.2°, 10.3±0.2°, 11.5±0.2°, 11.8±0.2°, 13.9±0.2°, 14.0±0.2°, 15.5±0.2°, 16.1±0.2°, 16.4±0.2°, 17.4±0.2°, 18.4±0.2°, 19.7±0.2°, and 19.9±0.2°.

[0022] In some embodiments, the crystal form III of the compound of formula (I) has substantially the following characteristics: Figure 5 The X-ray powder diffraction pattern shown is basically as follows: Figure 6 As shown.

[0023] Another aspect of the present invention is to provide a crystal form IV of a compound of formula (I), the structure of which is as shown above.

[0024] In some embodiments, the X-ray powder diffraction pattern of crystal form IV of the compound of formula (I) has a diffraction peak at 3.9 ± 0.2°; or at 6.8 ± 0.2°; or at 7.0 ± 0.2°; or at 7.8 ± 0.2°; or at 10.4 ± 0.2°; or at 10.7 ± 0.2°; or at 12.0 ± 0.2°; or at 12.3 ± 0.2°; or at 13.6 ± 0.2°; or at 14.1 ± 0.2°. The diffraction peak is present at 0.2°; or at 15.7±0.2°; or at 16.4±0.2°; or at 19.7±0.2°; or at 20.5±0.2°; or at 20.8±0.2°; or at 24.0±0.2°; or at 25.8±0.2°; preferably including any 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 or 17 of the above diffraction peaks, more preferably including any 6, 11 or 17 of them.

[0025] In some embodiments, the X-ray powder diffraction pattern of crystal form IV of the compound of formula (I) has diffraction peaks at 3.9±0.2°, 6.8±0.2°, 10.4±0.2°, 10.7±0.2°, 13.6±0.2°, and 14.1±0.2°;

[0026] In some embodiments, the X-ray powder diffraction pattern of crystal form IV of the compound of formula (I) shows diffraction peaks at 3.9±0.2°, 6.8±0.2°, 10.4±0.2°, 10.7±0.2°, 12.0±0.2°, 12.3±0.2°, 13.6±0.2°, 14.1±0.2°, 15.7±0.2°, 16.4±0.2°, and 19.7±0.2°.

[0027] In some embodiments, the X-ray powder diffraction pattern of crystal form IV of the compound of formula (I) has diffraction peaks at 3.9±0.2°, 6.8±0.2°, 7.0±0.2°, 7.8±0.2°, 10.4±0.2°, 10.7±0.2°, 12.0±0.2°, 12.3±0.2°, 13.6±0.2°, 14.1±0.2°, 15.7±0.2°, 16.4±0.2°, 19.7±0.2°, 20.5±0.2°, 20.8±0.2°, 24.0±0.2°, and 25.8±0.2°.

[0028] In some embodiments, the crystal form IV of the compound of formula (I) has substantially the following characteristics: Figure 7 The X-ray powder diffraction pattern shown is shown.

[0029] Another aspect of the present invention is to provide a crystal form V of a hydrate of a compound of formula (I), the structure of which is as shown above.

[0030] In some embodiments, the X-ray powder diffraction pattern of crystal form V of the hydrate of compound (I) has a diffraction peak at 8.2 ± 0.2°; or at 9.9 ± 0.2°; or at 10.5 ± 0.2°; or at 11.9 ± 0.2°; or at 13.1 ± 0.2°; or at 14.0 ± 0.2°; or at 16.3 ± 0.2°; or at 16.7 ± 0.2°; or at 18... The diffraction peak is present at 0.8 ± 0.2°; or at 19.2 ± 0.2°; or at 19.7 ± 0.2°; or at 21.1 ± 0.2°; or at 22.3 ± 0.2°; or at 25.3 ± 0.2°; or at 25.6 ± 0.2°; preferably including any 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15 of the above diffraction peaks, more preferably including any 5, 10 or 15 of them.

[0031] In some embodiments, the X-ray powder diffraction pattern of crystal form V of the hydrate of the compound of formula (I) has diffraction peaks at 8.2±0.2°, 10.5±0.2°, 11.9±0.2°, 25.3±0.2°, and 25.6±0.2°;

[0032] In some embodiments, the X-ray powder diffraction pattern of crystal form V of the hydrate of the compound of formula (I) has diffraction peaks at 8.2±0.2°, 10.5±0.2°, 11.9±0.2°, 13.1±0.2°, 14.0±0.2°, 16.7±0.2°, 18.8±0.2°, 22.3±0.2°, 25.3±0.2°, and 25.6±0.2°.

[0033] In some embodiments, the X-ray powder diffraction pattern of crystal form V of the hydrate of the compound of formula (I) has diffraction peaks at 8.2±0.2°, 9.9±0.2°, 10.5±0.2°, 11.9±0.2°, 13.1±0.2°, 14.0±0.2°, 16.3±0.2°, 16.7±0.2°, 18.8±0.2°, 19.2±0.2°, 19.7±0.2°, 21.1±0.2°, 22.3±0.2°, 25.3±0.2°, and 25.6±0.2°.

[0034] In some embodiments, the crystal form V of the hydrate of the compound of formula (I) has substantially the following characteristics: Figure 8 The X-ray powder diffraction pattern shown is basically as follows: Figure 9 As shown.

[0035] Another aspect of the present invention is to provide a crystal form VI of a compound of formula (I) having the structure shown above.

[0036] In some embodiments, the X-ray powder diffraction pattern of crystal form VI of the compound of formula (I) has a diffraction peak at 6.5 ± 0.2°; or at 8.1 ± 0.2°; or at 9.9 ± 0.2°; or at 10.5 ± 0.2°; or at 11.9 ± 0.2°; or at 13.0 ± 0.2°; or at 14.0 ± 0.2°; or at 19.2 ± 0.2°. The diffraction peaks are: either at 20.0 ± 0.2°, or at 20.3 ± 0.2°, or at 21.0 ± 0.2°, or at 22.3 ± 0.2°, or at 25.3 ± 0.2°, or at 28.4 ± 0.2°; preferably including any 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 of the above diffraction peaks, more preferably including any 4, 9 or 14 of them.

[0037] In some embodiments, the X-ray powder diffraction pattern of crystal form VI of the compound of formula (I) has diffraction peaks at 8.1±0.2°, 9.9±0.2°, 10.5±0.2°, and 11.9±0.2°;

[0038] In some embodiments, the X-ray powder diffraction pattern of crystal form VI of the compound of formula (I) has diffraction peaks at 6.5±0.2°, 8.1±0.2°, 9.9±0.2°, 10.5±0.2°, 11.9±0.2°, 13.0±0.2°, 14.0±0.2°, 19.2±0.2°, and 20.0±0.2°;

[0039] In some embodiments, the X-ray powder diffraction pattern of crystal form VI of the compound of formula (I) has diffraction peaks at 6.5±0.2°, 8.1±0.2°, 9.9±0.2°, 10.5±0.2°, 11.9±0.2°, 13.0±0.2°, 14.0±0.2°, 19.2±0.2°, 20.0±0.2°, 20.3±0.2°, 21.0±0.2°, 22.3±0.2°, 25.3±0.2°, and 28.4±0.2°.

[0040] In some embodiments, the crystal form VI of the compound of formula (I) has substantially the following characteristics: Figure 10 The X-ray powder diffraction pattern shown is shown.

[0041] Another object of the present invention is to provide a pharmaceutical composition comprising a therapeutically effective amount of the crystal form of the aforementioned compound of formula (I) or its hydrate, and one or more pharmaceutically acceptable carriers or excipients.

[0042] In some embodiments, the pharmaceutical composition further comprises other therapeutic agents.

[0043] In some embodiments, the other therapeutic agent is one or more of corticosteroids, protease inhibitors, and anti-inflammatory signal transduction modulators.

[0044] The present invention also aims to provide a crystal form of the compound of the aforementioned formula (I) or its hydrate, or the use of the above-mentioned pharmaceutical composition in the preparation of a medicament for treating or preventing diseases caused by feline infectious peritonitis virus infection or coronavirus infection.

[0045] In some embodiments, the disease caused by the feline infectious peritonitis virus infection is feline infectious peritonitis.

[0046] In some implementations, the coronavirus is the novel coronavirus SARS-CoV-2.

[0047] The present invention also aims to provide a method for treating or preventing diseases caused by feline infectious peritonitis virus infection or coronavirus infection, comprising the step of applying an effective amount of the above-mentioned compound or its hydrate crystal form or the above-mentioned pharmaceutical composition to the subject to be treated.

[0048] In some implementations, the disease caused by feline infectious peritonitis virus infection is feline infectious peritonitis.

[0049] In some implementations, the coronavirus is a feline coronavirus.

[0050] In some implementations, the coronavirus is the novel coronavirus SARS-CoV-2.

[0051] In some implementations, the subject of treatment is a human or an animal; further, the subject of treatment is a human or a cat.

[0052] Studies have shown that the crystal form of the compound of formula (I) prepared by this invention can meet the pharmaceutical requirements for production, transportation and storage. The production process is stable, repeatable and controllable, and can be adapted to industrial production. At the same time, it has high bioavailability, good efficacy and excellent safety. Attached Figure Description

[0053] Figure 1 The image shows the XRPD diagram of crystal form I of compound (I).

[0054] Figure 2 The DSC diagram shows the crystal form I of compound (I).

[0055] Figure 3 The image shows the XRPD diagram of crystal form II of compound (I).

[0056] Figure 4The DSC diagram shows the crystal form II of compound (I).

[0057] Figure 5 The image shows the XRPD diagram of crystal form III of compound (I).

[0058] Figure 6 The DSC diagram shows the crystal form III of compound (I).

[0059] Figure 7 The image shows the XRPD diagram of crystal form IV of compound (I).

[0060] Figure 8 The image shows the XRPD diagram of crystal form V of compound (I).

[0061] Figure 9 The DSC diagram shows the crystal form V of compound (I).

[0062] Figure 10 The image shows the XRPD diagram of crystal form VI of compound (I).

[0063] Figure 11 The pharmacokinetic curve of compound (I) in ICR mouse plasma (IV 10 mg / kg) is shown.

[0064] Figure 12 The pharmacokinetic curve of compound (I) in ICR mouse plasma (IG 25 mg / kg). Detailed Implementation

[0065] Unless otherwise stated, the terms used in the specification and claims have the following meanings.

[0066] The different terms "X is selected from A, B, or C", "X is selected from A, B, and C", "X is selected from A, B, or C", "X is selected from A, B, and C", "X is A, B, or C", and "X is A, B, and C" all express the same meaning, that is, X can be any one or more of A, B, and C.

[0067] The hydrogen atoms described in this invention can all be replaced by their isotope deuterium. Any hydrogen atom in the compounds of the embodiments of this invention can also be replaced by a deuterium atom.

[0068] "Optional" or "optionally" means that the event or circumstances described below may, but do not have to, occur. This description includes the circumstances in which the event or circumstances may or may not occur.

[0069] "Pharmaceutical composition" means a mixture containing one or more of the compounds described herein or their physiologically / pharmacologically acceptable salts or prodrugs, along with other chemical components and other components such as physiologically / pharmacologically acceptable carriers and excipients. The purpose of a pharmaceutical composition is to facilitate administration to a living organism, promote the absorption of the active ingredient, and thereby exert its biological activity.

[0070] "Medicinal salts" refer to the salts of the compounds of this invention. These salts are safe and effective when used in mammals and have the appropriate biological activity.

[0071] X-ray powder diffraction (XRPD) refers to the experimentally observed diffraction pattern or parameters derived from it, characterized by peak positions (x-axis) and peak intensities (y-axis). Those skilled in the art will understand that experimental errors depend on instrument conditions, sample preparation, and sample purity. In particular, it is known to those skilled in the art that X-ray diffraction patterns typically change with instrument conditions. Those skilled in the art should understand that suitable error tolerances for XRPD can be: 2θ ± 0.5°; 2θ ± 0.4°; 2θ ± 0.3°; 2θ ± 0.2°. It should be particularly noted that the relative intensity of the X-ray diffraction pattern may also change with experimental conditions, so the order of peak intensities cannot be considered the sole or decisive factor. Furthermore, the influence of experimental factors such as sample height can cause an overall shift in peak angles, which is generally permissible. Therefore, those skilled in the art will understand that any crystal form with characteristic peaks identical or similar to those of the patterns of this invention falls within the scope of this invention.

[0072] "DSC" refers to the Differential Scanning Calorimetry (DSC) experiment.

[0073] "HPLC" refers to High Performance Liquid Chromatography (HPLC) experiments.

[0074] "PK" refers to pharmacokinetic (PK) experiments.

[0075] The present invention is further described below with reference to embodiments, but these embodiments are not intended to limit the scope of the present invention.

[0076] 1. Instruments and Methods

[0077] 1.1 X-ray Powder Diffractometer (XRPD)

[0078] Table 1-1 XRPD Test Parameters

[0079]

[0080]

[0081] 1.2 Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC)

[0082] Table 1-2 TGA and DSC Test Parameters

[0083]

[0084]

[0085] 1.3 Proton NMR spectrum 1 HNMR)

[0086] Table 1-3 1 HNMR test parameters

[0087]

[0088] 1.4 High Performance Liquid Chromatography (HPLC)

[0089] Table 1-4 HPLC Methods

[0090]

[0091]

[0092] 1.5 Dynamic Moisture Adsorption (DVS)

[0093] Table 1-5 DVS Test Parameters

[0094]

[0095]

[0096] Thin-layer chromatography (TLC) uses Yantai Huanghai HSGF254 or Qingdao GF254 silica gel plates. The standard size for TLC is 0.15mm to 0.20mm, while the standard size for separating and purifying products using TLC is 0.4mm to 0.5mm. Column chromatography generally uses Yantai Huanghai 200-300 mesh silica gel as the carrier.

[0097] The starting materials used in the embodiments of the present invention are known and commercially available, or can be synthesized using or in accordance with methods known in the art.

[0098] Unless otherwise specified, all reactions in this invention are carried out under continuous magnetic stirring, in a dry nitrogen or argon atmosphere, using a dry solvent, and the reaction temperature is expressed in degrees Celsius.

[0099] Example 1

[0100] Synthesis of compound (I) (the product obtained is crystal form I)

[0101]

[0102] 25 g (1.0 eq) of GS-441524 was added to 200 mL of DMF for suspension, followed by 76.64 mL (6.7 eq) of N,N-dimethylformamide dimethyl acetal (DMF-DMA). The mixture was then heated in an oil bath at 60 °C for 1 hour. TLC monitoring was performed to ensure complete reaction (evolving solvent: dichloromethane / methanol = 10 / 1). After the reaction was complete, heating was stopped, and DMF was removed by rotary evaporation under reduced pressure. 50 mL of isopropanol and 150 mL of toluene were added, and the mixture was stirred and filtered to obtain 25 g of a white solid, with a yield of 84%. The proton NMR spectrum and LC-MS chromatogram of the product are shown below: 1 HNMR(500MHz,DMSO)δ8.94(s,1H),8.14(s,1H),6.98(d,J=4.5Hz,1H),6.82( d,J=4.5Hz,1H),6.11(d,J=6.4Hz,1H),5.21(d,J=5.1Hz,1H),4.91(t,J=5.7 Hz,1H),4.67(t,J=5.7Hz,1H),4.07(dd,J=8.5,4.5Hz,1H),3.98(dd,J=10.4 ,5.2Hz,1H),3.68–3.59(m,1H),3.56–3.45(m,1H),3.24(s,3H),3.18(s,3H).

[0103] HRMS(ESI):m / z calcd for[M+H]+:347.1462,found:347.1473.

[0104] Example 2

[0105] Preparation of crystal form II of compound (I)

[0106] Approximately 200 mg of crystal form I of compound (I) was weighed, and 5 mL of toluene was added. The mixture was stirred at 50°C for approximately 4 days, and the resulting solid was separated by filtration. The filter cake was dried under vacuum at room temperature for approximately 16 hours, and then dried at 50°C for approximately 16 hours to obtain crystal form II of compound (I). Analysis revealed that it possesses the following properties: Figure 3 The XRPD diagram shown is as follows: Figure 4 The DSC diagram shown.

[0107] Example 3

[0108] Preparation of crystal form III of compound (I)

[0109] Approximately 30 mg of crystal form I of compound (I) was weighed and added to 0.7 mL of isopropanol. After stirring at 50°C for about 3 days, the solid was centrifuged and dried under vacuum at room temperature for 3 days to obtain crystal form III of compound (I). Analysis revealed that it possesses the following properties: Figure 5 The XRPD diagram shown is as follows: Figure 6 The DSC diagram shown.

[0110] Example 4

[0111] Preparation of crystal form IV of compound (I)

[0112] Approximately 30 mg of crystal form I of compound (I) was weighed, added to 0.7 mL of acetonitrile, stirred at 5°C for approximately 3 days, and then centrifuged to obtain crystal form IV of compound (I). Analysis revealed that it possessed the following properties: Figure 7 The XRPD diagram shown.

[0113] Example 5

[0114] Preparation of crystal form V of compound (I)

[0115] Approximately 200 mg of crystal form I of compound (I) was weighed and added to 5 mL of tetrahydrofuran / n-heptane (1:3). After stirring at 5°C for approximately 8 days, the solid was filtered off. The filter cake was dried at 50°C for approximately 16 hours to obtain crystal form V of compound (I). Analysis revealed that it possesses the following properties: Figure 8 The XRPD diagram shown is as follows: Figure 9 The DSC diagram shown.

[0116] Example 6

[0117] Preparation of crystal form VI of compound (I)

[0118] Approximately 20 mg of crystal form I of compound (I) was weighed, added to 1 mL of water, and stirred at 37°C for 24 h. The resulting crystal form VI of compound (I) was then separated. Analysis revealed that it possessed the following properties: Figure 10 The XRPD diagram shown.

[0119] Example 7

[0120] Hybrid Competition Test

[0121] The suspension competition tests of crystal forms I / II / III / V were conducted in toluene (25°C and 50°C) and ethyl acetate (room temperature and 50°C), respectively. First, suspensions equilibrated for 2 hours at the corresponding temperatures and solvents were filtered (suspension preparation method: add the compound of formula (I) obtained in Example 1 to 1 mL of solvent, stir at the desired temperature, and continue adding the compound as it dissolves, until no further dissolution is possible, indicating a supersaturated suspension). This yielded saturated solutions of the compound at different temperatures. Then, solid-state physical mixtures of crystal forms I, II, III, and V were added. The physical mixtures of crystal forms I / II / III / V all converted to crystal form II in the toluene (room temperature and 50°C) system, and were a mixture of crystal forms I and II in the ethyl acetate (room temperature and 50°C) system. This indicates that within the temperature range of 25°C to 50°C (under 0 water activity conditions), both crystal forms II and I possess a certain degree of stability, with crystal form II exhibiting higher thermodynamic stability. The results are shown in Table 2.

[0122] Table 2 Results of the Hybrid Suspension Competition Test

[0123]

[0124] Example 8

[0125] Water activity test

[0126] Experiments were conducted with water activities (aw) of 0.248, 0.4, and 1.0 to investigate the interconversion relationships between crystal forms I / II / III / V. First, suspensions of Acetone / H₂O mixed solvent with different water contents were obtained by filtering suspensions equilibrated at room temperature for 2 hours (preparation method as in Example 7) to obtain saturated solutions of the compounds at 25°C. Then, solid mixtures of crystal forms I, II, III, and V were added. The results showed that crystal form I was relatively stable at water activities ranging from 0.248 to 0.4 at 25°C. The results are shown in Table 3.

[0127] Table 3 Summary of Water Activity Tests

[0128]

[0129] Example 9

[0130] Solid-state stability

[0131] Crystal forms I and II were placed under long-term (25℃ / 60%RH) conditions for 7 days and under high-temperature (60℃, RH<30%) conditions for 24 hours, respectively, and their HPLC purity and crystal form changes were tested. The results are summarized in Table 4.

[0132] HPLC: Crystal form I and crystal form II showed no significant change in purity after being placed at high temperature for 24 hours.

[0133] XRPD: Crystal forms I and II showed no significant changes in crystal form after 7 days of long-term storage and 24 hours of high-temperature storage.

[0134] Table 4 Solid-state stability assessment results

[0135]

[0136] Example 10

[0137] Hygroscopicity assessment

[0138] To assess the stability risk of samples at 25℃ with changes in humidity, DVS tests were performed on crystal forms I and II, and XRPD tests were conducted on the collected solid samples after the tests. The results are shown in Table 5. No crystal form change was observed in crystal form I samples before and after the DVS test, while some crystal form II samples partially transformed into crystal form I.

[0139] Table 5 Summary of Hygroscopicity Assessment Results

[0140] solid form Crystal form after testing Crystal form I Crystal form I Crystal form II Crystal form I

[0141] Example 11

[0142] equilibrium solubility

[0143] The equilibrium solubility of crystal forms I, II, and III in water (H₂O) was tested. In the experiment, crystal forms I, II, and III were prepared into suspensions (~20 mg / mL) in their respective buffer solutions and mixed at 37±2℃. After 24 h, samples of the suspensions were taken, and the supernatant was filtered to determine the concentration.

[0144] The results are shown in Table 6. Within 24 hours, the equilibrium solubilities of crystal form I, crystal form II, and crystal form III in H2O were 10.03 mg / mL, 9.90 mg / mL, and 1.1 mg / mL, respectively. Crystal form III was slightly soluble, while crystal form I was soluble, showing a significant difference in solubility.

[0145] Table 6 Equilibrium solubility results

[0146]

[0147]

[0148] Example 12

[0149] according to Figure 2 , Figure 3 and Figure 6The melting points of crystal form I, crystal form II, and crystal form III are shown in Table 7:

[0150] Table 7 Melting point results of crystal forms

[0151] solid form Melting point (°C) Crystal form I 159.77 Crystal form II 158.54 Crystal form III 178.69

[0152] Compared to crystal form III, crystal forms I and II of the present invention have better stable crystallization, but have a lower melting point, better solubility and stability. "Generally speaking, stable crystals of drugs have higher melting points and stability than metastable crystals" (Modern Pharmaceutics, edited by Ping Qineng et al., China Medical Science and Technology Press, 1st edition, 1st printing, October 1998, page 31, paragraph 3).

[0153] Example 13:

[0154] Pharmacokinetic experiments of compound (I) crystal form I:

[0155] Animals: Male ICR mice, weighing 20-25g, aged 6-8 weeks.

[0156] Drug information:

[0157] Sample Name Sample grouping content Formula (I) Dosage and testing Greater than 95%

[0158] Drug grouping:

[0159] Formula (I) Dosage Table

[0160]

[0161] The intravenous injection site is the tail vein.

[0162] Drug preparation method:

[0163] Take an appropriate amount of crystal form I powder, add 5% DMSO to dissolve it until clear according to the solvent ratio, then add 5% Solutol, vortex mix, add physiological saline, vortex mix to obtain a clear solution.

[0164] Note: Animals should be fasted for 12-16 hours before administration, but water can be allowed. After administration, animals should be fasted and water should be withheld, and food and water should be given 4 hours later.

[0165] Blood collection time points:

[0166] Intravenous injection: Pre-Dose, 0.083, 0.25, 0.5, 1, 2, 4, 8, 24.

[0167] Gavage: Pre-Dose, 0.25, 0.5, 1, 2, 4, 6, 8, 24.

[0168] Allowable error range for blood collection time:

[0169] Time point Acceptable time range 0.083h ±0.25 minutes 0.5-4h ±0.5 minutes 4-10h ±1 minute 10-24h ±2 minutes

[0170] Anticoagulant: K2-EDTA.

[0171] Whole blood sample processing method:

[0172] Whole blood samples were temporarily stored on ice and centrifuged at 4°C and 3000 rcf for 10 minutes within 1.5 hours. The supernatant (plasma) was then collected and stored at -20°C.

[0173] Detection method:

[0174] Instrument Name: Ultra-High Performance Liquid Chromatography-Mass Spectrometer; Instrument Model: XEVO TQ-S; Manufacturer: Waters

[0175] Liquid phase method:

[0176] Column: ACQUITY BEH C18 2.1x50mm 1.7μm

[0177] Mobile phase: 0.1% formic acid water (A) - acetonitrile (B) Flow rate: 0.35 mL / min Injection volume: 2 μL

[0178] mobile phase gradient:

[0179]

[0180] Mass spectrometry methods:

[0181] Source gas parameters:

[0182]

[0183]

[0184] Ion pair information:

[0185]

[0186] Sample preparation method:

[0187] Standard curve range: (2.00, 5.00, 10.00, 20.00, 50.00, 100.00, 200.00, 500.00, 1000.00, 2000.00, 5000.00, 10000.00) ng / mL

[0188] Quality control range: (6.00, 60.00, 800.00, 8000.00) ng / mL

[0189] Blank matrix: Blank plasma from male ICR mice

[0190] Preparation method of working solution: Take the compound stock solution and dilute it stepwise with DMSO:methanol:water = 2:2:1 to prepare standard working solutions containing (40, 100, 200, 400, 1000, 2000, 4000, 10000, 20000, 40000, 100000, 200000) ng / mL of each compound, and quality control working solutions containing (120, 1200, 16000, 160000) ng / mL of each compound.

[0191] Preparation and processing of standard curve and quality control samples: Take 47.5 μL of blank matrix and add 2.50 μL of standard curve working solution and quality control working solution to prepare standard curve and quality control samples respectively. Add 400 μL of acetonitrile (containing 2 ng / mL of internal standard verapamil), vortex for 3 min, centrifuge at 15000 rcf and 4℃ for 10 min, and take the supernatant for LC-MS / MS analysis.

[0192] Unknown sample preparation and processing: Take 50 μL of the sample to be tested, add 400 μL of acetonitrile (containing 2 ng / mL of internal standard verapamil), vortex for 3 min, centrifuge at 15000 rcf and 4℃ for 10 min, and take the supernatant for LC-MS / MS analysis.

[0193] Experimental results are as follows Figure 11 and Figure 12 As shown.

[0194] The calculated oral bioavailability of the tested compound (I) is approximately 89%, indicating good oral bioavailability and suitability for oral formulations.

[0195] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0196] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A compound having the chemical formula shown in formula (I): Formula (I); The compound has crystal form I, which has the X-ray powder diffraction pattern shown in Figure 1, and crystal form I of the compound is prepared by the following method: 25 g (1.0 eq) of GS-441524 was added to 200 mL of DMF for suspension, followed by 76.64 mL (6.7 eq) of N,N-dimethylformamide dimethyl acetal (DMF-DMA). The mixture was then heated in an oil bath at 60 °C for 1 hour. The reaction was monitored by TLC until complete, with a 10:1 dichloromethane:methanol eluent. After the reaction was complete, heating was stopped, and DMF was removed by rotary evaporation under reduced pressure. 50 mL of isopropanol and 150 mL of toluene were added, and the mixture was stirred and filtered to obtain the crystal form I of the compound of formula (I). The 1H NMR and LC-MS characteristics of the product are as follows: 1H NMR (500 MHz, DMSO) δ 8.94 (s, 1H), 8.14 (s, 1H), 6.98 (d, J = 4.5 Hz, 1H), 6.82 (d, J = 4.5 Hz, 1H), 6.11 (d, J = 4.5 Hz, 1H). 6.4 Hz, 1H), 5.21 (d, J = 5.1 Hz, 1H), 4.91 (t, J = 5.7 Hz, 1H), 4.67 (t, J = 5.7 Hz, 1H), 4.07 (dd, J = 8.5, 4.5Hz, 1H), 3.98 (dd, J = 10.4, 5.2 Hz, 1H), 3.68–3.59 (m, 1H), 3.56–3.45 (m,1H), 3.24 (s, 3H), 3.18 (s, 3H); HRMS (ESI): m / z calcd for [M+H]+: 347.1462, found: 347.1473.

2. The compound according to claim 1, characterized in that, The X-ray powder diffraction pattern of crystal form I shows a diffraction peak at 4.0±0.2°; or at 7.0±0.2°; or at 10.5±0.2°; or at 10.7±0.2°; or at 12.0±0.2°; or at 12.2±0.2°; or at 13.8±0.2°; or at 14.0±0.2°; or at 14.4±0.2°; or at 16.1±0.2°; or at 16.6±0.2°; or at 17.5±0.2°; or at 19.3±0.2°. Alternatively, a diffraction peak may be present at 20.1±0.2°; or at 20.5±0.2°; or at 20.8±0.2°; or at 21.2±0.2°; or at 25.7±0.2°.

3. The compound according to claim 2, characterized in that, The X-ray powder diffraction pattern of crystal form I of the compound includes any one of the diffraction peaks at 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17 or 18.

4. The compound according to claim 3, characterized in that, The X-ray powder diffraction pattern of crystal form I of the compound includes any 6, 12, or 18 diffraction peaks.

5. The compound according to claim 1, characterized in that, The X-ray powder diffraction pattern of crystal form I shows diffraction peaks at 4.0±0.2°, 7.0±0.2°, 10.5±0.2°, 10.7±0.2°, 13.8±0.2° and 14.0±0.2°.

6. The compound according to claim 1, characterized in that, The X-ray powder diffraction pattern of crystal form I of formula (I) shows diffraction peaks at 4.0±0.2°, 7.0±0.2°, 10.5±0.2°, 10.7±0.2°, 12.0±0.2°, 12.2±0.2°, 13.8±0.2°, 14.0±0.2°, 14.4±0.2°, 17.5±0.2°, 20.1±0.2°, and 25.7±0.2°.

7. The compound according to claim 1, characterized in that, The X-ray powder diffraction pattern of crystal form I of formula (I) shows diffraction peaks at 4.0±0.2°, 7.0±0.2°, 10.5±0.2°, 10.7±0.2°, 12.0±0.2°, 12.2±0.2°, 13.8±0.2°, 14.0±0.2°, 14.4±0.2°, 16.1±0.2°, 16.6±0.2°, 17.5±0.2°, 19.3±0.2°, 20.1±0.2°, 20.5±0.2°, 20.8±0.2°, 21.2±0.2°, and 25.7±0.2°.

8. The compound according to claim 6, characterized in that, The DSC spectrum of crystal form I of formula (I) is basically as shown in Figure 2.

9. A pharmaceutical composition comprising a therapeutically effective amount of crystal form I of the compound of any one of claims 1-8 and one or more pharmaceutically acceptable carriers and / or excipients.

10. The pharmaceutical composition of claim 9, further comprising other therapeutic agents, said other therapeutic agents being one or more of corticosteroids, protease inhibitors, and anti-inflammatory signal transduction modulators.

11. Use of the compound of any one of claims 1-8, or the pharmaceutical composition of any one of claims 9-10, in the preparation of a medicament for treating or preventing diseases caused by feline infectious peritonitis virus infection or coronavirus infection; wherein the disease caused by feline infectious peritonitis virus infection is feline infectious peritonitis.

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