β-Lactam Compounds, Their Crystal Forms, Preparation Methods and Uses

Abstract

The present invention relates to a β-lactam compound, its preparation method and uses. The β-lactam compound has a structure shown in formula (I), where n = 0-6. The X-ray powder diffraction pattern of its crystal form A has characteristic diffraction peaks at diffraction angles 2θ of 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 not only has improved drug efficacy, but also has improved solubility and stability.

Description

Technical Field

[0001] The present invention relates to the technical field of medicinal chemistry, and more particularly, to a β-lactam compound, its crystal form, preparation method and use. The present invention also relates to a composition comprising the β-lactam compound. Background Art

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

[0003] The present invention is made to overcome the above-mentioned deficiencies in the prior art.

[0004] The present invention provides a new β-lactam compound, which is a compound of formula (I):

[0005]

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

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

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

[0009] Unexpectedly, it has now been found that compared with the amorphous form of the compound of formula (I), the crystal form A can further improve solubility and stability, which is beneficial for preparing into forms such as powder for injection and used for injection, etc. Therefore, when preparing injection solutions, etc., the present invention allows the use of less solvent to dissolve the sample, which is beneficial for reducing costs and improving the utilization rate of the product.

[0010] In addition, the present invention 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]

[0013] In addition, the present invention also provides a method for preparing crystalline form A of the compound of formula (I), which further comprises:

[0014] Adding a poor solvent of the compound of formula (I) to the salt-forming solution at a temperature of 0 °C - 30 °C to form crystals.

[0015] Furthermore, the present invention also provides a pharmaceutical composition, which is characterized in that it comprises the compound of formula (I) of the present invention or the compound of formula (I) prepared according to the method of the present invention, and a pharmaceutically acceptable adjuvant.

[0016] In addition, the present invention also provides the use of the compound of formula (I) of the present invention or the pharmaceutical composition of the present invention for combating Gram-negative bacteria, particularly Escherichia coli, Klebsiella pneumoniae, Klebsiella aerogenes, Enterobacter cloacae, Citrobacter freundii and / or Proteus mirabilis, particularly Klebsiella pneumoniae. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figures 1 to 6 XRPD diagrams of crystalline form A prepared according to Examples 1 to 6 of the present invention, respectively;

[0018] Figure 7 Crystal structure of crystalline form A obtained in Example 2 of the present invention;

[0019] Figures 8 to 9 TGA diagrams of crystalline form A prepared according to Examples 1 and 2 of the present invention, respectively;

[0020] Figure 10 DSC diagram of crystalline form A prepared according to Example 2 of the present invention;

[0021] Figure 11 XRPD diagram of the free acid form of the β-lactam compound prepared according to Comparative Example 1;

[0022] Figure 12 XRPD diagram of the amorphous form of the β-lactam compound prepared according to Comparative Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0023] In one aspect, the present invention provides a compound of formula (I):

[0024]

[0025] wherein n = 0 - 6, preferably 0.5 - 5, more preferably 2 - 3. In a specific embodiment, n is 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4 or 4.5.

[0026] Furthermore, the present invention also provides polymorph A of the compound of formula (I), and its X-ray powder diffraction (XRPD) Figure 2 has characteristic diffraction peaks at diffraction angles θ of 5.8±0.2°, 10.8±0.2°, 15.3±0.2°, 17.4±0.2° and 18.6±0.2°.

[0027] More preferably, the X-ray powder diffraction of the polymorph A Figure 2 also has characteristic diffraction peaks at diffraction angles θ of 21.3±0.2° and 36.6±0.2°.

[0028] Even more preferably, the X-ray powder diffraction of the polymorph A Figure 2 also has characteristic diffraction peaks at diffraction angles θ of 5.1±0.2°, 11.5±0.2° and 13.1±0.2°.

[0029] In a preferred embodiment of the present invention, the thermogravimetric analysis (TGA) graph of the polymorph A has a weight loss of 7.4%-11.2% in the entire 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 graph of the polymorph A has a weight loss of 0.5%-1.5% in the entire range of 30-53 °C, preferably has a weight loss of 1.0±0.3%; more preferably, the thermogravimetric analysis graph of the polymorph A has a weight loss of 7.6%-10.0% in the entire range of 53.1-170 °C, preferably has a weight loss of 9.5±0.3%; still more preferably, the thermogravimetric analysis graph of the polymorph A has a weight loss of 1.0%-2.5% in the entire range of 95-170 °C, preferably has a weight loss of 1.5±0.2%.

[0030] In a preferred embodiment of the present invention, the differential scanning calorimetry (DSC) of the polymorph A has an endothermic peak in the range of 70-125 °C, preferably has endothermic peaks at 80±2 °C and 110±2 °C, and more preferably has an endothermic peak at 110±2 °C.

[0031] In a preferred embodiment of the present invention, the X-ray powder diffraction pattern of the polymorph A is substantially as Figure 2 shown.

[0032] On the other hand, the present invention provides a method for preparing the compound of formula (I), comprising: step (1), dissolving the compound of formula (A-1) and a sodium transfer agent in a good solvent to form a salt:

[0033]

[0034] The compound of formula (A-1) is known and can be easily obtained by those skilled in the art or prepared according to the methods disclosed in the prior art, such as the method disclosed in patent application CN113754651A, the disclosure of which is incorporated herein by reference.

[0035] In a preferred embodiment of the present invention, the good solvent is selected from at least one of methanol, water, DMSO and DMF, preferably at least one of methanol and water.

[0036] In a preferred embodiment of the present invention, the sodium transfer agent is selected from at least one of sodium lactate, sodium bicarbonate, sodium carbonate, sodium isooctanoate and sodium acetate, preferably at least one of sodium isooctanoate and sodium acetate.

[0037] In a preferred embodiment of the present invention, the amount of the good solvent is 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).

[0038] In a preferred embodiment of the present invention, 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.

[0039] In a preferred embodiment of the present invention, the compound of formula (I) obtained in step (1) is further crystallized. Unexpectedly, it has been found in the present invention that crystalline form A of the compound of formula (I) can be prepared, which further includes: step (2), adding a poor solvent of the compound of formula (I) to the salt-forming solution obtained in step (1) at a temperature of 0°C - 30°C to form crystals.

[0040] The crystallization temperature 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 crystallization temperature in step (2) is the same as the temperature in step (1).

[0041] In a preferred embodiment of the present invention, in step (2), the poor solvent is selected from at least one of ethyl acetate, petroleum ether, ethanol, acetone, isopropanol and ether, preferably selected from at least one of ethyl acetate, ethanol, acetone and isopropanol.

[0042] Preferably, when the sodium transfer agent is selected from at least one of sodium isooctanoate and sodium acetate, the good solvent is selected from at least one of methanol and water. More preferably, when the sodium transfer agent is selected from at least one of sodium bicarbonate and sodium carbonate, the good solvent is water.

[0043] In a preferred embodiment of the present invention, the volume ratio of the good solvent to the poor solvent can be 1:(1 - 20), preferably 1:(3 - 17), and more preferably 1:(4 - 12).

[0044] In a preferred embodiment of the present invention, it further comprises step (3): filtering the crystals obtained in step (2), washing the crystals with a poor solvent and drying them.

[0045] In a preferred embodiment of the present invention, in step (3), the drying temperature is 0 - 80 °C, preferably 15 - 55 °C, and more preferably 30 - 45 °C.

[0046] In another aspect, the present invention provides a pharmaceutical composition which comprises the compound of formula (I) of the present invention or the compound of formula (I) prepared by the method according to the present invention and a pharmaceutically acceptable adjuvant.

[0047] In the present invention, 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.

[0048] In a preferred embodiment of the present invention, the pharmaceutical composition can be in any dosage form, such as tablets, pills, capsules, powders, granules or suppositories, etc.

[0049] In the present invention, the pharmaceutical composition can also be an injection, especially a powder for injection.

[0050] In another aspect, the present invention also provides the use of the compound of formula (I) of the present invention or its pharmaceutical composition for combating Gram-negative bacteria, especially Escherichia coli, Klebsiella pneumoniae, Klebsiella aerogenes, Enterobacter cloacae, Citrobacter freundii and / or Proteus mirabilis, especially Klebsiella pneumoniae.

[0051] Surprisingly, the compound of formula (I) of the present invention has improved antibacterial efficacy compared with the free acid, especially the efficacy against Klebsiella pneumoniae. Therefore, the compound of formula (I) of the present invention or its pharmaceutical composition is also preferably used for treating infectious diseases related to the above-mentioned bacteria.

[0052] In addition, in the present invention, Na in the compound of formula (I) can also be replaced by K or NH4. It is also found that the crystal form A of the compound of formula (I) of the present invention has better crystallinity, stability and / or hygroscopicity compared with the crystal forms of the corresponding other salts.

[0053] Embodiment

[0054] The following examples are provided to better illustrate the present invention. It should be understood that the examples are merely exemplary and should not be construed as limiting the scope of the present invention.

[0055] In the present invention, unless otherwise stated, all temperatures are room temperature (25 ± 2 °C) and the pressure is atmospheric pressure (101 kPa).

[0056] General description

[0057] 1. The measurement information of X-ray powder diffraction (XRPD) is as follows:

[0058] Detection instrument: Empyrean X-ray diffractometer

[0059] 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.

[0060] Detection basis: X-ray Diffraction Method in Section IV of the Chinese Pharmacopoeia 2020 Edition, 0451.

[0061] 2. The measurement information of thermogravimetric analysis (TGA) is as follows:

[0062] Analysis instrument: TA Q5000; heating rate: 10 °C per minute; protective gas: nitrogen.

[0063] 3. The measurement information of differential scanning calorimetry (DSC) is as follows:

[0064] Analysis instrument: TA Q2000; temperature change rate: 5 °C per minute; protective gas: nitrogen.

[0065] Preparation Examples

[0066] Comparative Example 1: Preparation of the compound of formula (A-1)

[0067] The compound of formula (A-1) was prepared in the manner described in Preparation Example 1 of Patent Application CN 113754651A. Characterized by XRPD, shown in Figure 11 .

[0068] It can be seen from Figure 11 that the compound of formula (A-1) does not show the characteristic peaks of crystals, and this compound has an amorphous structure.

[0069] Example 1: Preparation of the compound of formula (I)

[0070] At 3 °C, 8 g of sodium isooctanoate was dissolved in 50 mL of water, then 10 g of the compound of formula (A-1) prepared according to Comparative Example 1 was added. At 3 °C, 500 mL of acetone was added to the above mixture, and then the mixture was stirred at this temperature for crystallization. After complete crystallization, it was filtered, washed with an appropriate amount of acetone, and dried in vacuo at 40 °C to obtain crystalline form A of the compound of formula (I) with a yield of 87%. Characterized by XRPD and TGA, which are shown in Figure 1 and Figure 8 .

[0071] As Figure 1 shown, the X-ray powder diffraction pattern of crystalline form A prepared according to Example 1 of the present invention 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, there are also 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°.

[0072] As Figure 8 shown, when the crystalline form A prepared according to Example 1 of the present invention was heated to 170 °C, the weight loss was 10.42%. This crystalline form A lost 0.86% of its weight in the range of 30 - 55 °C (this part is free water and solvent), and lost 9.56% of its weight in the range of 55.1 - 170 °C (this part is crystal water). By calculation, it can be obtained that the crystalline form A obtained in Example 1 is disodium trihydrate, that is, n in formula (I) is 3.

[0073] Example 2

[0074] At 5 °C, 4 g of sodium acetate was dissolved in 30 mL of water, then 10 g of the compound of formula (A-1) prepared according to Comparative Example 1 was added to the above sodium acetate solution at 5 °C. 350 mL of isopropanol was added to the above mixture, and then the mixture was stirred at this temperature for crystallization. After complete crystallization, it was filtered, washed with an appropriate amount of isopropanol, and dried in vacuo at 35 °C to obtain crystalline form A of the compound of formula (I) with a yield of 94%. Characterized by XRPD, TGA and DSC, which are shown in Figure 2 、 Figure 9 and Figure 10 .

[0075] As Figure 2As shown, the X-ray powder diffraction pattern of crystalline form A prepared according to Example 2 of the present invention 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, there are also 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°.

[0076] As Figure 9 shown, when the crystalline form A prepared according to Example 2 of the present invention is heated to 170 °C, the weight loss is 10.72%. This crystalline form A loses 1.03% of its weight in the range of 30 - 53 °C (this part is free water and solvent), and loses 9.67% of its weight in the range of 53.1 - 170 °C (this part is crystal water). By calculation, it can be obtained that the crystalline form A obtained in Example 2 is disodium trihydrate, that is, n in formula (I) is 3.

[0077] As Figure 10 shown, the crystalline form A prepared according to Example 2 of the present invention has endothermic peaks at 79.9 °C and 110.3 °C.

[0078] In addition, single crystal structure analysis was performed on the crystalline form A obtained in Example 2. The results show that the crystalline form A has a monoclinic P21 space group. The unit cell parameters are listed in Table 1 below, and the single crystal structure is shown in Figure 7 .

[0079] Table 1 Unit cell parameters

[0080]

[0081] Example 3

[0082] 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; at 5 °C, 100 mL of ethanol was added to the above mixture, and then stirred for crystallization at this temperature. After complete crystallization, it was filtered, washed with an appropriate amount of ethanol, and dried in vacuo at 45 °C to obtain crystalline form A of the compound of formula (I) with a yield of 87%. Characterized by XRPD, it is shown in Figure 3 .

[0083] As Figure 3 shown, the X-ray powder diffraction pattern of crystalline form A prepared according to Example 3 of the present invention 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, there are also 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°.

[0084] Example 4

[0085] 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 isooctanoate was added; at 15 °C, 500 mL of acetone was added to the above mixture, and then crystallization was carried out with stirring at this temperature. After complete crystallization, filtration was carried out, washed with an appropriate amount of acetone, and dried in vacuo at 40 °C to obtain crystalline form A of the compound of formula (I) with a yield of 89%. Characterized by XRPD, shown in Figure 4 .

[0086] As Figure 4 shown, the X-ray powder diffraction pattern of crystalline form A prepared according to Example 4 of the present invention 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, there are also 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°.

[0087] Example 5

[0088] At 12 °C, 6 g of sodium acetate was dissolved in 20 mL of water, and then 10 g of the compound of formula (A-1) prepared according to Comparative Example 1 was added. At 12 °C, 300 mL of isopropanol was added to the above mixture, and then crystallization was carried out with stirring at this temperature. After complete crystallization, filtration was carried out, washed with an appropriate amount of isopropanol, and dried in vacuo at 30 °C to obtain crystalline form A of the compound of formula (I) with a yield of 92%. Characterized by XRPD, shown in Figure 5 .

[0089] As Figure 5 shown, the X-ray powder diffraction pattern of crystalline form A prepared according to Example 5 of the present invention 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, there are also 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°.

[0090] Example 6

[0091] At 23 °C, 10 g of the compound of formula (A-1) prepared according to Comparative Example 1 was dissolved in 30 mL of water, and then 4 g of sodium bicarbonate was added; at 23 °C, 360 mL of ethanol was added to the above mixture, and then crystallization was carried out with stirring at this temperature. After the crystallization was complete, filtration was carried out, and the residue was washed with an appropriate amount of ethanol and dried in vacuo at 35 °C to obtain crystalline form A of the compound of formula (I) with a yield of 89%. Characterized by XRPD, shown in Figure 6 .

[0092] As Figure 6 shown, the X-ray powder diffraction pattern of crystalline form A prepared according to Example 6 of the present invention 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, there are also 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°.

[0093] Comparative Example 2

[0094] 1 g of crystalline form A of the compound of formula (I) obtained in Example 1 was dissolved in 10 mL of water, and then freeze-dried to obtain an amorphous solid of the compound of formula (I). Characterized by XRPD, shown in Figure 12 .

[0095] It can be seen from Figure 12 that the obtained compound does not show the characteristic peaks of crystals and is an amorphous structure.

[0096] Effect Example

[0097] 1. In vitro pharmacodynamic test

[0098] To evaluate the antibacterial activity of the compound of formula (I) (prepared in Example 2), in vitro antibacterial activity studies were carried out with reference to aztreonam, ceftazidime / avibactam, cefepime, amikacin, ciprofloxacin, colistin, meropenem, ertapenem and tigecycline.

[0099] Determination of minimum inhibitory concentration (MIC)

[0100] According to the CLSI standard, the agar dilution method was used for the drug sensitivity test. The test bacteria were enriched and cultured in an appropriate liquid or solid medium. The drugs were serially diluted two-fold with broth medium to various required concentrations, and appropriate amounts were added to petri dishes respectively. After the agar medium was melted, it was quantitatively poured into the petri dishes containing the drug solutions and mixed evenly, so that the final concentrations of the drugs in the petri dishes were 128, 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.12, 0.06, 0.03 μg / mL respectively. The test bacteria were inoculated using a multi-point inoculator, and the inoculation amount was about 104 CFU / point. It was incubated at 35 °C in a constant temperature incubator, and the results were observed after 18 h. The minimum concentration of the drug in the petri dish without bacterial growth was the minimum inhibitory concentration (MIC). The results are listed in Tables 2 and 3 below.

[0101] Table 2-1 MIC determination of the compound of formula (I) and its control drugs against clinically isolated bacteria (μg / mL)

[0102]

[0103]

[0104] Note: CRE represents carbapenem-resistant Enterobacter

[0105] Table 2-2 MIC determination of the compound of formula (I) and its control drugs against clinically isolated bacteria (μg / mL)

[0106]

[0107] Table 3-1 MIC determination of the compound of formula (I) and its control drugs against carbapenem-resistant strains (μg / mL)

[0108]

[0109]

[0110] Note: CRECL represents carbapenem-resistant Enterobacter cloacae, and CREC represents carbapenem-resistant Escherichia coli

[0111] Table 3-2 MIC determination of the compound of formula (I) and its control drugs against ESBLs-producing strains (μg / mL)

[0112]

[0113] Note: ESBLs represents β-lactamase

[0114] The test results show that the compound of formula (I) has strong antibacterial effects against a variety of clinically common Gram-negative bacteria (including ESBLs-producing strains and carbapenem-resistant strains), and has strong antibacterial effects against Escherichia coli, Klebsiella pneumoniae, Klebsiella aerogenes, Enterobacter cloacae, Citrobacter freundii and Proteus mirabilis.

[0115] The compound of formula (I) has strong antibacterial activity against 150 strains of Escherichia coli, and the MIC50 and MIC90 values are 0.12 and 2 μg / mL respectively. Among them, 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 it is significantly better than aztreonam, ciprofloxacin and cefepime.

[0116] The compound of formula (I) has strong antibacterial activity against 45 strains of CREC, and the MIC50 and MIC90 values are 1 and 32 μg / mL respectively. Among them, the antibacterial activity of the compound of formula (I) is similar to that of meropenem, 2 times that of ertapenem, and it is better than aztreonam, ceftazidime / avibactam, cefepime, amikacin and ciprofloxacin.

[0117] The compound of formula (I) has strong antibacterial activity against 57 strains of ESBLs-producing Escherichia coli (non-CREC strains), and the MIC50 and MIC90 values are 0.12 and 0.5 μg / mL respectively. Among them, the antibacterial activity of the compound of formula (I) is similar to that of colistin and tigecycline, 8 times that of amikacin, and it is significantly better than aztreonam, cefepime and ciprofloxacin.

[0118] The compound of formula (I) has strong antibacterial activity against 167 strains of Klebsiella pneumoniae, and the MIC50 and MIC90 values are 0.12 and 4 μg / mL respectively. Among them, the antibacterial activity of the compound of formula (I) is 8 times that of amikacin, 16 times that of cefepime, ciprofloxacin and meropenem, and it is better than aztreonam and ertapenem, and slightly weaker than tigecycline.

[0119] The compound of formula (I) has strong antibacterial activity against 56 strains of CRKP, and the MIC50 and MIC90 values are 2 and 32 μg / mL respectively. Among them, the antibacterial activity of the compound of formula (I) is 2 times that of meropenem, 4 times that of cefepime and ciprofloxacin, and it is better than aztreonam, amikacin and ertapenem.

[0120] The compound of formula (I) has relatively strong antibacterial activity against 30 strains of ESBLs-producing Klebsiella pneumoniae (non-CRKP strains), and the MIC50 and MIC90 values are 0.5 and 16 μg / mL respectively. Among them, 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.

[0121] 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. Among them, the antibacterial activity of the compound of formula (I) is similar to that of ertapenem, 4 times that of ciprofloxacin, and superior to aztreonam, ceftazidime / avibactam, cefepime and amikacin.

[0122] 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. Among them, the antibacterial activity of the compound of formula (I) is similar to that of ertapenem, 4 times that of ciprofloxacin, and superior to aztreonam, ceftazidime / avibactam, cefepime and amikacin.

[0123] 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. Among them, the antibacterial activity of the compound of formula (I) is similar to that of ceftazidime / avibactam and ertapenem, 2 times that of colistin and tigecycline, 8 times that of amikacin, and 16 times that of aztreonam.

[0124] The compound of formula (I) has strong antibacterial activity against 37 strains of Proteus mirabilis, and the MIC50 and MIC90 values are both ≤0.03 and ≤0.03 μg / mL. Its antibacterial activity is similar to that of aztreonam / avibactam and ertapenem, superior to aztreonam, ceftazidime / avibactam and meropenem, and significantly superior to cefepime, amikacin, ciprofloxacin, colistin and tigecycline.

[0125] 2. Antibacterial activity comparison experiment

[0126] The antibacterial activity results 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 listed in Table 4 below. The minimum inhibitory concentration MIC was determined as described above.

[0127] Table 4 Antibacterial activity results

[0128]

[0129] The test results show that compared with the compound of formula (A-1), the compound of formula (I) of the present invention has a better effect against Klebsiella pneumoniae.

[0130] 2. Solubility test

[0131] The solubilities of the compound of formula (A-1) prepared according to Comparative Example 1, polymorph 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 were measured at room temperature, and the test results are listed in Table 5 below:

[0132] Table 5 Solubility data

[0133]

[0134] As can be seen from Table 2, the crystalline form A of the compound of formula (I) of the present invention can achieve improved solubility even without using a cosolvent. Unexpectedly, the crystalline form A of the present invention shows higher solubility compared to its amorphous form.

[0135] 3. Stability

[0136] Six portions each weighing 1 g of the crystalline form A of the compound of formula (I) prepared according to Example 2 of the present invention and six portions each weighing 1 g of the amorphous form of the compound of formula (I) prepared according to Comparative Example 2 were stored in a thermostatic and humidity-controlled chamber at 25°C / 60% RH. Their contents, pH values, and moisture were measured after intervals of time as shown in Table 6 below (month refers to the natural month). The test results are summarized in Table 6, where the active ingredient content refers to the content of the compound of formula (I), in wt%.

[0137] Table 6 Stability data

[0138]

[0139] As can be seen from the above table, after storage of the crystalline form A of the present invention at 25°C / 60% RH for up to 12 months, its various qualities remain basically unchanged, indicating its high stability. In contrast, the corresponding amorphous compound shows lower stability.

[0140] Although several preferred embodiments of the present invention have been described for illustrative purposes, those of ordinary skill in the art will understand that various modifications, additions, and substitutions are possible without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims

1. Compound of formula (I): （I）， where n = 0 - 6.

2. The compound of formula (I) according to claim 1, where n = 2 - 3.

3. The compound of formula (I) according to claim 1 or 2, which is crystalline form A, and the X-ray powder diffraction pattern of the crystalline form A 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°.

4. The compound of formula (I) according to claim 3, where the X-ray powder diffraction pattern of the crystalline form A further has characteristic diffraction peaks at 2θ diffraction angles of 21.3 ± 0.2° and 36.6 ± 0.2°.

5. The compound according to claim 4, where the X-ray powder diffraction pattern of the crystalline form A further has characteristic diffraction peaks at 2θ diffraction angles of 5.1 ± 0.2°, 11.5 ± 0.2° and 13.1 ± 0.2°.

6. The compound of formula (I) according to claim 3, which has the X-ray powder diffraction pattern shown in Figure 2.

7. The compound of formula (I) according to claim 3, which has a monoclinic P21 space group and the following unit cell parameters: a=13.2305(5)Å，α= 90° b=11.7483(4)Å，β=107.352(5)° c = 18.0941(9) Å, γ = 90°.

8. A method for preparing the compound of formula (I) according to any one of claims 1 - 7, comprising: Salifying the compound of formula (A-1) and a sodium transfer agent in a good solvent, （A-1） where the good solvent is selected from at least one of methanol, water, DMSO and DMF, the sodium transfer agent is selected from at least one of sodium lactate, sodium bicarbonate, sodium carbonate, sodium isooctanoate and sodium acetate, and the dosage of the good solvent is 0.5 - 20 mL / g of the compound of formula (A-1).

9. The method according to claim 8, where the good solvent is selected from at least one of methanol and water.

10. The method according to claim 8, where the sodium transfer agent is selected from at least one of sodium isooctanoate and sodium acetate.

11. The method according to claim 8, where the dosage of the good solvent is 1 - 10 mL / g of the compound of formula (A-1).

12. The method according to claim 11, where the dosage of the good solvent is 2 - 6 mL / g of the compound of formula (A-1).

13. The method according to claim 8, which further comprises: Adding a poor solvent of the compound of formula (I) to the salified solution at a temperature of 0°C - 30°C to form crystals, where the poor solvent is selected from at least one of ethyl acetate, petroleum ether, ethanol, acetone, isopropanol and ether, and the volume ratio of the good solvent to the poor solvent is 1:(1 - 20).

14. The method according to claim 13, where the poor solvent is selected from at least one of ethyl acetate, ethanol, acetone and isopropanol.

15. The method according to claim 13, where the volume ratio of the good solvent to the poor solvent is 1:(3 - 17).

16. A pharmaceutical composition, characterized in that, It includes a compound of formula (I) according to any one of claims 1 to 7 or a compound of formula (I) prepared by the method according to any one of claims 8 to 15, and a pharmaceutically acceptable adjuvant.

17. The pharmaceutical composition according to claim 16, which is in the form of tablets, pills, capsules, powders, granules, suppositories or injections.

18. The pharmaceutical composition according to claim 17, which is in the form of a powder for injection.

19. Use of a compound of formula (I) according to any one of claims 1 to 7 or a pharmaceutical composition according to any one of claims 16 to 18 in the preparation of a drug for combating Gram-negative bacteria, wherein the Gram-negative bacteria are Escherichia coli, Klebsiella pneumoniae, Klebsiella aerogenes, Enterobacter cloacae and / or Proteus mirabilis.

20. The use according to claim 19, wherein the drug is for treating infectious diseases associated with the Gram-negative bacteria.

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