Β-lactam compound, crystal form thereof, preparation method therefor, and use thereof

Abstract

The present invention relates to a β-lactam compound, a preparation method therefor, and a use thereof. The β-lactam compound has a structure as represented by formula (I), where n = 0-6. The X-ray powder diffraction pattern of crystal form A thereof has characteristic diffraction peaks at diffraction angles of 2θ at 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2°, and 18.6±0.2° The β-lactam compound of the present invention has improved efficacy and has improved solubility and stability.

Description

Beta-lactam compounds, crystalline forms thereof, preparation methods and uses thereof TECHNICAL FIELD

[0001] The present application relates to the technical field of pharmaceutical chemistry, in particular to a beta-lactam compound, a crystalline form thereof, a preparation method and uses thereof. The present application also relates to a composition comprising the beta-lactam compound. BACKGROUND

[0002] To date, various antibacterial agents have been developed, such as beta-lactams, aminoglycosides, tetracyclines, fluoroquinolones, glycopeptides, macrolides, etc. Patent application CN 113754651A discloses a novel beta-lactam compound, which has good antibacterial properties and low drug resistance to bacteria, especially gram-negative bacteria, and has good prospects for effectively treating various diseases. However, there is still a need to further improve its physical properties and efficacy.

[0003] SUMMARY

[0004] The present application is made to overcome the above-mentioned deficiencies in the prior art.

[0005] The present application provides a novel beta-lactam compound, which is a compound of formula (I):

[0006] wherein n = 0-6, preferably 2-3.

[0007] The compound of formula (I) of the present application is in the form of a sodium salt. Surprisingly, it has been found that the compound of the present application has improved efficacy against Klebsiella pneumoniae compared to the free acid of the prior art. Specifically, the compound of the present application exhibits a lower minimum inhibitory concentration.

[0008] In addition, the present application also provides a new crystalline form A of the compound of formula (I), which has characteristic diffraction peaks at 2θ diffraction angles of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2° and 18.6±0.2° in the X-ray powder diffraction pattern.

[0009] Unexpectedly, it has been found that the crystalline form A can further improve the solubility and stability compared to the amorphous form of the compound of formula (I), thereby facilitating the preparation into a form of a powder injection and the like for injection and the like. Therefore, when preparing an injection and the like, the present application allows using less solvent to dissolve the sample, thereby benefiting the reduction of cost and the improvement of the availability of the product.

[0010] In addition, the present application also provides a method for preparing the compound of formula (I), comprising:

[0011] salifying the compound of formula (A-1) and a sodium transfer agent in a good solvent,

[0012] In addition, the present application also provides a method for preparing the crystalline form A of the compound of formula (I), which further comprises:

[0013] At a temperature of 0°C to 30°C, a poor solvent of the compound of formula (I) is added to the salted solution to form crystals.

[0014] In addition, the present application also provides a pharmaceutical composition, characterized in that it comprises the compound of formula (I) of the present application or the compound of formula (I) prepared according to the method of the present application, and a pharmaceutically acceptable auxiliary.

[0015] In addition, the present application also provides the use of the compound of formula (I) of the present application or the pharmaceutical composition of the present application for resisting Gram-negative bacteria, in particular Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Citrobacter freundii and / or Proteus mirabilis, in particular Klebsiella pneumoniae. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figures 1 to 6 are XRPD patterns of the crystalline form A prepared according to Examples 1 to 6 of the present application, respectively;

[0017] Figure 7 is a crystal structure of the crystalline form A obtained in Example 2 of the present application;

[0018] Figures 8 to 9 are TGA patterns of the crystalline form A prepared according to Examples 1 and 2 of the present application, respectively;

[0019] Figure 10 is a DSC pattern of the crystalline form A prepared according to Example 2 of the present application;

[0020] Figure 11 is an XRPD pattern of the β-lactam compound in free acid form prepared according to Comparative Example 1;

[0021] Figure 12 is an XRPD pattern of the β-lactam compound in amorphous form prepared according to Comparative Example 2. DETAILED DESCRIPTION

[0022] In one aspect, the present application provides a compound of formula (I):

[0023] wherein n = 0-6, preferably 0.5-5, more preferably 2-3. In a particular embodiment, n is 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4 or 4.5.

[0024] Further, the present application also provides a crystalline form A of the compound of formula (I) as described above, having an X-ray powder diffraction (XRPD) pattern with characteristic peaks at 2-theta angles of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2° and 18.6±0.2°.

[0025] More preferably, the X-ray powder diffraction pattern of the crystalline form A further has characteristic peaks at 2-theta angles of 21.3±0.2° and 36.6±0.2°.

[0026] Further preferably, the X-ray powder diffraction pattern of the crystalline form A further has characteristic peaks at 2-theta angles of 5.1±0.2°, 11.5±0.2°, 13.1±0.2°.

[0027] In a preferred embodiment of the present application, the thermogravimetric analysis (TGA) pattern of the crystalline form A has a weight loss of 7.4%-11.2% in the range of 30-170°C, preferably has a weight loss of 10.3±0.5%, and more preferably has a weight loss of 9.6±1.0%; more preferably, the thermogravimetric analysis pattern of the crystalline form A has a weight loss of 0.5%-1.5% in the range of 30-53°C, preferably has a weight loss of 1.0±0.3%; more preferably, the thermogravimetric analysis pattern of the crystalline form A has a weight loss of 7.6%-10.0% in the range of 53.1-170°C, preferably has a weight loss of 9.5±0.3%; and more preferably, the thermogravimetric analysis pattern of the crystalline form A has a weight loss of 1.0%-2.5% in the range of 95-170°C, preferably has a weight loss of 1.5±0.2%.

[0028] In a preferred embodiment of the present application, the differential scanning calorimetry (DSC) pattern of the crystalline form A has an endothermic peak in the range of 70-125°C, preferably has an endothermic peak at 80±2°C and 110±2°C, and more preferably has an endothermic peak at 110±2°C.

[0029] In a preferred embodiment of the present application, the X-ray powder diffraction pattern of the crystalline form A is substantially as shown in Figure 2.

[0030] In another aspect, the present application provides a method for preparing the compound of formula (I) as described above, comprising: step (1), dissolving a compound of formula (A-1) and a sodium transfer agent in a good solvent to form a salt:

[0031] The compound of formula (A-1) is known and can be readily obtained by those skilled in the art or prepared according to the methods disclosed in the prior art, for example, the methods disclosed in patent application CN113754651A, the disclosure of which is incorporated herein by reference.

[0032] In a preferred embodiment of the present application, the good solvent is selected from at least one of methanol, water, DMSO and DMF, preferably at least one of methanol and water.

[0033] In a preferred embodiment of the present application, the sodium transfer agent is selected from at least one of sodium lactate, sodium bicarbonate, sodium carbonate, sodium iso-octoate and sodium acetate, preferably at least one of sodium iso-octoate and sodium acetate.

[0034] In a preferred embodiment of the present application, the good solvent is used in an amount of 0.5-20 mL / g of the compound of formula (A-1), preferably 1-10 mL / g of the compound of formula (A-1), more preferably 2-6 mL / g of the compound of formula (A-1); preferably, the molar ratio of the compound of formula (A-1) to the sodium transfer agent is 1:(1-6), preferably 1:(1.5-4), more preferably 1:(2-3.5).

[0035] In a preferred embodiment of the present application, the temperature of step (1) is 0°C-35°C, preferably 2-23°C, more preferably 4-20°C, still more preferably 6-15°C or 10-20°C.

[0036] In a preferred embodiment of the present application, the compound of formula (I) obtained in step (1) is further crystallized. Unexpectedly, the present application has found that a crystalline form A of the compound of formula (I) can be prepared, which further comprises: step (2), adding a poor solvent of the compound of formula (I) to the solution obtained in step (1) at a temperature of 0°C-30°C, to form crystals.

[0037] The temperature of crystallization in step (2) can be 0°C-25°C, preferably 2-23°C, more preferably 4-20°C, still more preferably 6-15°C or 10-20°C. Preferably, the temperature of crystallization in step (2) is the same as the temperature of step (1).

[0038] In a preferred embodiment of the present application, in step (2), the poor solvent is selected from at least one of ethyl acetate, petroleum ether, ethanol, acetone, isopropyl alcohol and diethyl ether, preferably at least one of ethyl acetate, ethanol, acetone and isopropyl alcohol.

[0039] Preferably, when the sodium transfer agent is selected from at least one of sodium iso-octoate and sodium acetate, the good solvent is selected from at least one of methanol and water. Still preferably, when the sodium transfer agent is selected from at least one of sodium bicarbonate and sodium carbonate, the good solvent is water.

[0040] In a preferred embodiment of the present application, the volume ratio of the good solvent to the poor solvent can be 1:(1-20), preferably 1:(3-17), still preferably 1:(4-12).

[0041] In a preferred embodiment of the present application, it further comprises step (3): filtering the crystallization obtained in step (2), washing the crystallization with a poor solvent and drying.

[0042] In a preferred embodiment of the present application, in step (3), the drying temperature is 0-80°C, preferably 15-55°C, and more preferably 30-45°C.

[0043] In another aspect, the present application provides a pharmaceutical composition comprising a compound of formula (I) of the present application or a compound of formula (I) prepared according to the method of the present application and a pharmaceutically acceptable adjuvant.

[0044] In the present application, the term "pharmaceutically acceptable adjuvant" includes, but is not limited to, at least one of arginine, sodium bicarbonate, sodium carbonate, sulbactam sodium and avibactam sodium.

[0045] In a preferred embodiment of the present application, the pharmaceutical composition can be in any dosage form, such as tablets, pills, capsules, powders, granules or suppositories, etc.

[0046] In the present application, the pharmaceutical composition can also be an injection, in particular a powder injection.

[0047] In another aspect, the present application also provides the use of a compound of formula (I) of the present application or a pharmaceutical composition thereof for resisting Gram-negative bacteria, in particular Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Citrobacter freundii and / or Proteus mirabilis, in particular Klebsiella pneumoniae.

[0048] Surprisingly, the compound of formula (I) of the present application has improved antibacterial efficacy, in particular against Klebsiella pneumoniae, compared with the free acid. Therefore, the compound of formula (I) of the present application or a pharmaceutical composition thereof is also preferably used for treating infectious diseases associated with the above-mentioned bacteria.

[0049] In addition, in the present application, Na in the compound of formula (I) can also be replaced by K or NH4. It is also found that the crystalline form A of the compound of formula (I) of the present application has better crystallinity, stability and / or hygroscopicity compared with the crystalline form of the corresponding other salt.

[0050] Examples

[0051] The following examples are provided to better illustrate the present application. It is understood that the examples are merely illustrative, and should not be construed as limiting the scope of the present application.

[0052] In the present application, all temperatures are room temperature (25±2°C) and the pressure is atmospheric pressure (101 kPa) unless otherwise specified.

[0053] General remarks

[0054] 1. The measurement information of X-ray powder diffraction (XRPD) is as follows:

[0055] Detection instrument: Empyrean X-ray diffractometer

[0056] Detection conditions: Cu target Kα ray, voltage 40 kV, current 40 mA, divergence slit 1 / 8°, anti-scattering slit 1 / 4°, anti-scattering slit 7.5 mm, 2θ range: 3°-60°, step size 0.02°, dwell time per step 40 s.

[0057] Detection according to: “People's Republic of China Pharmacopoeia” 2020 edition volume 4 0451 X-ray diffraction method.

[0058] 2. The measurement information of thermal gravimetric analysis (TGA) is as follows:

[0059] Analysis instrument: TA Q5000; heating rate: 10℃ per minute; protective gas: nitrogen.

[0060] 3. The measurement information of differential scanning calorimetry (DSC) is as follows:

[0061] Analysis instrument: TA Q2000; temperature change rate: 5℃ per minute; protective gas: nitrogen.

[0062] Preparation examples

[0063] Comparative example 1: preparation of compound of formula (A-1)

[0064] The compound of formula (A-1) was prepared according to the manner described in Preparation Example 1 in patent application CN 113754651A. Characterized by XRPD, shown in Figure 11.

[0065] As can be seen from Figure 11, the compound of formula (A-1) does not show the characteristic peaks of crystals, and the compound is in amorphous structure.

[0066] Example 1: preparation of compound of formula (I)

[0067] 8 g of sodium isooctanoate was dissolved in 50 mL of water at 3℃, then 10 g of compound of formula (A-1) prepared according to comparative example 1 was added, 500 mL of acetone was added to the above mixture at 3℃, then the crystallization was stirred at this temperature, after the crystallization was completed, it was filtered, washed with appropriate amount of acetone, and vacuum dried at 40℃ to obtain crystal form A of compound of formula (I) with a yield of 87%. Characterized by XRPD and TGA, shown in Figure 1 and Figure 8 respectively.

[0068] As shown in Figure 1, the X-ray powder diffraction pattern of the crystal form A prepared according to the embodiment 1 of the present application has the following characteristic peaks: characteristic diffraction peaks at 2-theta of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2° and 18.6±0.2°, in addition, also has characteristic diffraction peaks at 21.3±0.2°, 36.6±0.2°, 5.1±0.2°, 11.5±0.2° and 13.1±0.2°.

[0069] As shown in Figure 8, the crystal form A prepared according to the embodiment 1 of the present application has a weight loss of 10.42% when heated to 170°C. The crystal form A has a weight loss of 0.86% in the range of 30-55°C (this part is free water and solvent), and a weight loss of 9.56% in the range of 55.1-170°C (this part is crystal water), by calculation, it can be concluded that the crystal form A obtained in the embodiment 1 is disodium trihydrate, that is, n in formula (I) is 3.

[0070] Embodiment 2

[0071] At 5°C, 4g of sodium acetate was dissolved in 30mL of water, then 10g of the compound of formula (A-1) prepared according to the comparative embodiment 1 was added into the above sodium acetate solution at 5°C, 350mL of isopropyl alcohol was added into the above mixture, then crystallization was carried out at this temperature under stirring, after the crystallization was completed, it was filtered, washed with appropriate amount of isopropyl alcohol, and dried under vacuum at 35°C to obtain the crystal form A of the compound of formula (I) with a yield of 94%. It was characterized by XRPD, TGA and DSC, which are shown in Figure 2, Figure 9 and Figure 10, respectively.

[0072] As shown in Figure 2, the X-ray powder diffraction pattern of the crystal form A prepared according to the embodiment 2 of the present application has the following characteristic peaks: characteristic diffraction peaks at 2-theta of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2° and 18.6±0.2°, in addition, also has characteristic diffraction peaks at 21.3±0.2°, 36.6±0.2°, 5.1±0.2°, 11.5±0.2° and 13.1±0.2°.

[0073] As shown in Figure 9, the crystal form A prepared according to the embodiment 2 of the present application has a weight loss of 10.72% when heated to 170°C. The crystal form A has a weight loss of 1.03% in the range of 30-53°C (this part is free water and solvent), and a weight loss of 9.67% in the range of 53.1-170°C (this part is crystal water), by calculation, it can be concluded that the crystal form A obtained in the embodiment 2 is disodium trihydrate, that is, n in formula (I) is 3.

[0074] As shown in Figure 10, the crystal form A prepared according to the embodiment 2 of the present application has endothermic peaks at 79.9°C and 110.3°C.

[0075] In addition, the crystal form A obtained in Example 2 was subjected to single crystal structure analysis, and as a result, it was shown that the crystal form A has a monoclinic P21 space group, and the unit cell parameters are listed in Table 1 below, and the single crystal structure is shown in FIG. 7.

[0076] Table 1 Unit cell parameters

[0077] Example 3

[0078] At 5°C, 10 g of the compound of formula (A-1) prepared according to Comparative Example 1 was dissolved in 20 mL of water, and then 4 g of sodium carbonate was added; to the above mixture, 100 mL of ethanol was added at 5°C, and then crystallization was performed by stirring at this temperature, and after the crystallization was completed, it was filtered, washed with an appropriate amount of ethanol, and dried at 45°C under vacuum to obtain the crystal form A of the compound of formula (I) at a yield of 87%. It was characterized by XRPD, and shown in FIG. 3.

[0079] As shown in FIG. 3, the X-ray powder diffraction pattern of the crystal form A prepared according to Example 3 of the present application has characteristic peaks at 2-theta of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2°, and 18.6±0.2°, and in addition, has characteristic peaks at 21.3±0.2°, 36.6±0.2°, 5.1±0.2°, 11.5±0.2°, and 13.1±0.2°.

[0080] Example 4

[0081] At 15°C, 10 g of the compound of formula (A-1) prepared according to Comparative Example 1 was dissolved in 30 mL of methanol and water (volume ratio 1:1), and then 7 g of sodium iso-octanoate was added; to the above mixture, 500 mL of acetone was added at 15°C, and then crystallization was performed by stirring at this temperature, and after the crystallization was completed, it was filtered, washed with an appropriate amount of acetone, and dried at 40°C under vacuum to obtain the crystal form A of the compound of formula (I) at a yield of 89%. It was characterized by XRPD, and shown in FIG. 4.

[0082] As shown in FIG. 4, the X-ray powder diffraction pattern of the crystal form A prepared according to Example 4 of the present application has characteristic peaks at 2-theta of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2°, and 18.6±0.2°, and in addition, has characteristic peaks at 21.3±0.2°, 36.6±0.2°, 5.1±0.2°, 11.5±0.2°, and 13.1±0.2°.

[0083] Example 5

[0084] In 12°C, 6g of sodium acetate was dissolved in 20mL of water, then 10g of the compound of formula (A-1) prepared according to Comparative Example 1 was added, to the above mixture, 300mL of isopropyl alcohol was added at 12°C, then crystallization was carried out by stirring at this temperature, after the crystallization was completed, it was filtered, washed with appropriate amount of isopropyl alcohol, dried at 30°C under vacuum, to obtain the crystal form A of the compound of formula (I) with a yield of 92%. It was characterized by XRPD, shown in Figure 5.

[0085] As shown in Figure 5, the X-ray powder diffraction pattern of the crystal form A prepared according to Example 5 of the present application has the following characteristic peaks: characteristic diffraction peaks at 2θ of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2° and 18.6±0.2°, in addition, also has characteristic diffraction peaks at 21.3±0.2°, 36.6±0.2°, 5.1±0.2°, 11.5±0.2° and 13.1±0.2°.

[0086] Example 6

[0087] In 23°C, 10g of the compound of formula (A-1) prepared according to Comparative Example 1 was dissolved in 30mL of water, then 4g of sodium bicarbonate was added; to the above mixture, 360mL of ethanol was added at 23°C, then crystallization was carried out by stirring at this temperature, after the crystallization was completed, it was filtered, washed with appropriate amount of ethanol, dried at 35°C under vacuum, to obtain the crystal form A of the compound of formula (I) with a yield of 89%. It was characterized by XRPD, shown in Figure 6.

[0088] As shown in Figure 6, the X-ray powder diffraction pattern of the crystal form A prepared according to Example 6 of the present application has the following characteristic peaks: characteristic diffraction peaks at 2θ of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2° and 18.6±0.2°, in addition, also has characteristic diffraction peaks at 21.3±0.2°, 36.6±0.2°, 5.1±0.2°, 11.5±0.2° and 13.1±0.2°.

[0089] Comparative Example 2

[0090] 1g of the crystal form A of the compound of formula (I) obtained from Example 1 was dissolved in 10mL of water, then freeze-dried, to obtain the amorphous solid of the compound of formula (I). It was characterized by XRPD, shown in Figure 12.

[0091] As can be seen from Figure 12, the obtained compound does not show the characteristic peaks of crystals, and is an amorphous structure.

[0092] Effect Example

[0093] 1. In vitro pharmacodynamic test

[0094] To evaluate the antibacterial activity of the compound of formula (I) (prepared from Example 2), the in vitro antibacterial activity studies were performed against the control drugs Aztreonam, Ceftazidime / avibactam, Cefepime, Amikacin, Ciprofloxacin, Colistin, Meropenem, Ertapenem and Tegecycline.

[0095] Minimum inhibitory concentration (MIC) determination

[0096] The susceptibility test was performed by agar dilution method according to CLSI standard. The test strains were inoculated in appropriate liquid or solid medium for culture, and the drugs were diluted in broth medium to the required concentrations, and then added to the plates. After the agar medium was melted, it was added to the plates containing the drug solution and mixed well, so that the final concentration of the drug in the plate was 128, 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.12, 0.06, 0.03 μg / mL. The test strains were inoculated using a multipoint inoculator at a dose of about 104CFU / point, and incubated at 35°C. The results were observed after 18h. The minimum concentration of the drug contained in the sterile growth plate was the minimum inhibitory concentration (MIC). The results are shown in Tables 2 and 3 below.

[0097] Table 2-1 MIC determination of the compound of formula (I) and its control drugs against clinical isolates (μg / mL) Note: CRE represents carbapenem-resistant Enterobacteriaceae

[0098] Table 2-2 MIC determination of the compound of formula (I) and its control drugs against clinical isolates (μg / mL)

[0099] Table 3-1 MIC determination of the compound of formula (I) and its control drugs against carbapenem-resistant strains (μg / mL) Note: CRE CL represents carbapenem-resistant Enterobacter cloacae, and CRE C represents carbapenem-resistant Escherichia coli

[0100] Table 3-2 MIC determination of the compound of formula (I) and its control drugs against ESBLs-producing strains (μg / mL) Note: ESBLs represents β-lactamase

[0101] The test results show that the compound of formula (I) has strong antibacterial effect on various clinically common gram-negative bacteria (including ESBLs-producing strains, carbapenem-resistant strains), and has strong antibacterial effect on Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Citrobacter freundii and Proteus mirabilis.

[0102] The compound of formula (I) has strong antibacterial activity on 150 strains of Escherichia coli, and the MIC50 and MIC90 values are 0.12 μg / mL and 2 μg / mL respectively. The antibacterial activity of the compound of formula (I) is 2 times that of meropenem, 4 times that of amikacin, and 8 times that of ertapenem, and is obviously better than that of aztreonam, ciprofloxacin and cefepime.

[0103] The compound of formula (I) has strong antibacterial activity on 45 strains of CREC strains, and the MIC50 and MIC90 values are 1 μg / mL and 32 μg / mL respectively. The antibacterial activity of the compound of formula (I) is similar to that of meropenem, 2 times that of ertapenem, and is better than that of aztreonam, ceftazidime / avibactam, cefepime, amikacin and ciprofloxacin.

[0104] The compound of formula (I) has strong antibacterial activity on 57 strains of ESBLs-producing Escherichia coli (non-CREC strains), and the MIC50 and MIC90 values are 0.12 μg / mL and 0.5 μg / mL respectively. The antibacterial activity of the compound of formula (I) is similar to that of colistin and tigecycline, 8 times that of amikacin, and is obviously better than that of aztreonam, cefepime and ciprofloxacin.

[0105] The compound of formula (I) has strong antibacterial activity on 167 strains of Klebsiella pneumoniae, and the MIC50 and MIC90 values are 0.12 μg / mL and 4 μg / mL respectively. The antibacterial activity of the compound of formula (I) is 8 times that of amikacin, 16 times that of cefepime, ciprofloxacin and meropenem, is better than that of aztreonam and ertapenem, and is slightly weaker than that of tigecycline.

[0106] The compound of formula (I) has strong antibacterial activity on 56 strains of CRKP, and the MIC50 and MIC90 values are 2 μg / mL and 32 μg / mL respectively. The antibacterial activity of the compound of formula (I) is 2 times that of meropenem, 4 times that of cefepime and ciprofloxacin, and is better than that of aztreonam, amikacin and ertapenem.

[0107] The compound of formula (I) has strong antibacterial activity on 30 strains of ESBLs-producing Klebsiella pneumoniae (non-CRKP strains), and the MIC50 and MIC90 values are 0.5 μg / mL and 16 μg / mL respectively. The antibacterial activity of the compound of formula (I) is 2 times that of cefepime, 4 times that of ciprofloxacin, and 8 times that of aztreonam.

[0108] The compound of formula (I) has strong antibacterial activity against 55 strains of Enterobacter cloacae, and the MIC50 and MIC90 values are 4 and 32 μg / mL respectively. The antibacterial activity of the compound of formula (I) is similar to that of ertapenem, 4 times that of ciprofloxacin, and better than that of amikacin, amikacin, cefepime and amikacin.

[0109] The compound of formula (I) has strong antibacterial activity against 39 strains of CRECL, and the MIC50 and MIC90 values are 8 and 32 μg / mL respectively. The antibacterial activity of the compound of formula (I) is similar to that of ertapenem, 4 times that of ciprofloxacin, and better than that of amikacin, amikacin, cefepime and amikacin.

[0110] The compound of formula (I) has strong antibacterial activity against 36 strains of Enterobacter aerogenes, and the MIC50 and MIC90 values are 0.12 and 0.25 μg / mL respectively. The antibacterial activity of the compound of formula (I) is similar to that of cefoperazone / avibactam and ertapenem, 2 times that of colistin and tigecycline, 8 times that of amikacin, and 16 times that of amikacin.

[0111] The compound of formula (I) has strong antibacterial activity against 37 strains of Proteus mirabilis, and the MIC50 and MIC90 values are ≤0.03 and ≤0.03 μg / mL respectively. The antibacterial activity is similar to that of amikacin / avibactam and ertapenem, better than that of amikacin, cefoperazone / avibactam and meropenem, and significantly better than that of cefepime, amikacin, ciprofloxacin, colistin and tigecycline.

[0112] 2. Comparison of antibacterial activity

[0113] The results of the antibacterial activity of the compound of formula (A-1) prepared according to Comparative Example 1 and the compound of formula (I) prepared according to Example 2 against Klebsiella pneumoniae are shown in Table 4 below. The minimum inhibitory concentration MIC was determined as described above.

[0114] Table 4. Results of antibacterial activity

[0115] The test results show that the compound of formula (I) of the present application has a better effect against Klebsiella pneumoniae than the compound of formula (A-1).

[0116] 2. Solubility test

[0117] The solubility of the compound of formula (A-1) prepared according to Comparative Example 1, the crystalline form A of the compound of formula (I) prepared according to Example 2 and the amorphous form of the compound of formula (I) prepared according to Comparative Example 2 was determined at room temperature, and the test results are shown in Table 5 below:

[0118] Table 5. Solubility data

[0119] As can be seen from Table 2, the crystalline Form A of the compound of formula (I) according to the present application can achieve improved solubility even without the use of a cosolvent. Surprisingly, the crystalline Form A according to the present application shows higher solubility than its amorphous form.

[0120] 3. Stability

[0121] Six 1 g samples of the crystalline Form A of the compound of formula (I) prepared according to Example 2 of the present application and six 1 g samples of the amorphous form of the compound of formula (I) prepared according to Comparative Example 2 were stored in a constant temperature and humidity test chamber at 25°C / 60% RH, respectively. The content, pH value and moisture of each sample were tested after an interval shown in Table 6 (month means natural month). The test results are summarized in Table 6, wherein the active content refers to the content of the compound of formula (I) in wt%.

[0122] Table 6 Stability data

[0123] As can be seen from the above table, the crystalline Form A according to the present application has substantially unchanged quality after being stored at 25°C / 60% RH for 12 months, which indicates that it has high stability. In contrast, the corresponding amorphous compound shows lower stability.

[0124] Although several preferred embodiments of the present application have been described for illustrative purposes, those of ordinary skill in the art will appreciate that various modifications, additions and substitutions are possible without departing from the spirit and scope of the present application as defined by the appended claims.

Claims

1. Compound of formula (I): wherein n = 0-6, preferably 2-3.

2. The compound according to claim 1, which is in crystalline Form A having an X-ray powder diffractogram 2Q diffraction angles with characteristic diffraction peaks at 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2° and 18.6±0.2°, preferably further at 21.3±0.2° and 36.6±0.2°, more preferably further at 5.1±0.2°, 11.5±0.2°, 13.1±0.2°.

3. The compound according to any one of claims 1 to 3, having an X-ray powder diffractogram as shown in Figure 2.

4. The compound of any one of claims 1 to 4, having monoclinic P21 space group and the following unit cell parameters: α = 90° β = 107.352(5)° γ = 90°.

5. A process for preparing a compound of formula (I) according to any one of claims 1 to 4, comprising: The compound of formula (A-1) and the sodium transfer reagent are dissolved in a good solvent to form a salt, wherein the good solvent is preferably selected from at least one of methanol, water, DMSO and DMF, more preferably at least one of methanol and water; the sodium transfer agent is preferably selected from at least one of sodium lactate, sodium bicarbonate, sodium carbonate, sodium iso-octoate and sodium acetate, more preferably at least one of sodium iso-octoate and sodium acetate; the good solvent is preferably used in an amount of 0.5-20 mL / g of compound of formula (A-1), more preferably 1-10 mL / g of compound of formula (A-1), most preferably 2-6 mL / g of compound of formula (A-1).

6. The process according to claim 5, further comprising: adding a poor solvent for the compound of formula (I) to the solution after salification at a temperature of 0-30 °C, to form crystals, wherein the poor solvent is preferably selected from at least one of ethyl acetate, petroleum ether, ethanol, acetone, isopropanol and diethyl ether, more preferably at least one of ethyl acetate, ethanol, acetone and isopropanol, the volume ratio of good solvent to poor solvent is preferably 1 : (1-20), more preferably 1 : (3-17).

7. A pharmaceutical composition, characterized by, which comprises a compound of formula (I) according to any one of claims 1 to 4 or prepared according to the process of claim 5 or 6, and pharmaceutically acceptable auxiliaries.

8. The pharmaceutical composition according to claim 7, in the form of a tablet, a pill, a capsule, a powder, a granule, a suppository or an injection, in particular in the form of a powder injection.

9. Use of a compound of formula (I) according to any one of claims 1 to 4 or of a pharmaceutical composition according to claim 6 or 7 for combating gram-negative bacteria, in particular Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Citrobacter freundii and / or Proteus mirabilis.

10. Use according to claim 10 for the treatment of infectious diseases associated with gram-negative bacteria, in particular Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Citrobacter freundii and / or Proteus mirabilis.

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