Cephalosporin-siderophore conjugate as well as preparation method and application thereof

Abstract

The invention provides a cephalosporin-siderophore conjugate as well as a preparation method and application thereof. Specifically, the invention provides a compound or pharmaceutically acceptable salt, raceme, tautomer, optical isomer or isomer mixture thereof, and the compound is shown as a formula A. The invention further provides a preparation method of the compound. The cephalosporin-siderophore conjugate of the present invention has improved stability and excellent antibacterial activity. # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the fields of pharmacology, drug synthesis and pharmacology. Specifically, it relates to cephalosporin-siderophore conjugates, a preparation method thereof, and uses thereof in the treatment of bacterial infectious diseases. Background Art

[0002] In recent years, the widespread use and even abuse of antibiotics have made the problem of bacterial drug resistance increasingly serious. Bacterial drug resistance has posed a new threat to human health, and drug resistance trends have emerged in both Gram-positive and Gram-negative bacteria. Among Gram-positive bacteria, drug-resistant ones include methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE), penicillin-resistant Streptococcus pneumoniae (PRSP), multi-drug resistant Mycobacterium tuberculosis, and vancomycin-resistant Enterococcus (VRE), etc.; among Gram-negative bacteria, multi-drug resistant ones include Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii. Compared with Gram-positive bacteria, Gram-negative bacteria have poor cell membrane permeability and complex drug resistance mechanisms, and their drug resistance incidence and lethality are more serious than those of Gram-positive bacteria. The increasing community-acquired multi-drug resistant (MDR) Gram-negative bacteria, such as Escherichia coli and Neisseria gonorrhoeae, and hospital-acquired extensively drug-resistant (XDR) and total drug-resistant (TDR) Gram-negative bacteria, such as Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae, are extremely difficult to treat and almost have no available drugs, resulting in a very high mortality rate of XDR and TDR infections in hospitals. For example, carbapenem-resistant Enterobacteriaceae (CRE) has a pathogenic mortality rate as high as 70%. Currently, there is an extreme lack of candidate drugs for effectively treating drug-resistant Gram-negative bacterial infections, and it is urgent to develop candidate drugs for treating infections caused by multi-drug resistant Gram-negative bacteria.

[0003] The reduction of outer membrane permeability is one of the important mechanisms of drug resistance in Gram-negative bacteria. There is a bacterial outer membrane composed of lipopolysaccharide, lipid bilayer and lipoprotein on the outside of the cell wall of Gram-negative bacteria, while Gram-positive bacteria have no extracellular membrane. The outer membrane of Gram-negative bacteria can prevent antibiotics from entering the bacterial cell, so Gram-negative bacteria have natural drug resistance to a variety of antibacterial drugs. In addition, Gram-negative bacteria can also express a variety of efflux pumps, recognize and pump antibacterial drugs out of the cell, or express a variety of hydrolases to inactivate antibacterial drugs. Therefore, finding new compounds that can enter bacteria through a new mechanism and overcome the drug resistance mechanisms of bacterial efflux pumps and porin mutations is the most important direction for the current research and development of new anti-multi-drug resistant Gram-negative bacteria drugs.

[0004] One of the strategies to increase the transmembrane rate of antibacterial drugs is to utilize the principle of bacteria's iron uptake to connect antibacterial drugs with siderophores to form conjugate compounds. When bacteria acquire iron, they actively transport both the antibacterial drug and iron into the bacteria, effectively overcoming the barrier of the difficult-to-permeate outer membrane of Gram-negative bacteria. The following formula shows the structure of cefiderocol, a representative β-lactam-siderophore conjugate drug. The introduction of the quaternary ammonium structure in this compound makes the molecule positively charged, which is conducive to its electrostatic interaction with negatively charged lipopolysaccharide or lipoteichoic acid on the microbial membrane, promoting the transmembrane of cefiderocol.

[0005]

[0006] In 2019, the FDA approved the siderophore-β-lactam antibiotic Fetroja (Cefiderocol) from Shionogi & Co., Ltd. for the treatment of complicated urinary tract infections (cUTIs), ventilator-associated pneumonia, community-acquired pneumonia, and hospital-acquired pneumonia in patients 18 years of age and older. Cefiderocol is the only successfully marketed siderophore-β-lactam antibiotic globally and is also known as the "sixth-generation cephalosporin".

[0007] However, cefiderocol also has obvious deficiencies: First, although the special side-chain quaternary ammonium salt structure of cefiderocol improves transmembrane, its chemical stability is poor. After being stored at room temperature for a long time, two impurities (Impurity I and II) as shown below will be produced, significantly reducing its potency and purity. The possible mechanism for the generation of its impurities is that the carbon atom on the thiazole ring of one molecule of cefiderocol attacks the allylic position of another molecule of cefiderocol, the tertiary amine fragment leaves, and at the same time, the β-lactam ring hydrolyzes and opens. Second, the antibacterial activity of cefiderocol is medium, especially its antibacterial activity against the most difficult-to-treat Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae is relatively weak. Third, the quaternary ammonium structure of cefiderocol may cause allergic reactions. Animal experiments in rats and monkeys have shown that after using cefiderocol, obvious injection site side reactions and histopathological lesions will occur at the injection site, specifically manifested as local blackening, peeling, scabbing, trauma, red lesions in the subcutaneous tissue, and dermatitis.

[0008]

[0009] Considering the disadvantages of existing cephalosporin-siderophore conjugates, such as weak antibacterial activity, poor stability, narrow antibacterial spectrum, and inability to fully cover important multi-drug resistant Gram-negative bacteria such as Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii, there is an urgent need in this field for a new class of cephalosporin derivatives with novel structures, stronger antibacterial activity, and broader antibacterial spectra. Summary of the Invention

[0010] The object of the present invention is to provide a class of cephalosporin-siderophore conjugates with novel structures, stronger anti-Gram-negative bacterial activity, broader antibacterial spectra, and better stability.

[0011] In the first aspect of the present invention, there is provided a compound or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture thereof, wherein the compound is as shown in Formula A;

[0012]

[0013] Wherein,

[0014] n1 is 1 or 2;

[0015] n2 is 1 or 2;

[0016] X is CR 1 or N;

[0017] R 1 is selected from the group consisting of: hydrogen, halogen (such as F, Cl, Br or I), C1-C4 alkyl (such as methyl), C1-C4 haloalkyl (such as trifluoromethyl), C1-C3 alkoxy (-O-C1-C3 alkyl), C1-C3 alkylthio (-S-C1-C3 alkyl);

[0018] R 2A and R 2B are each independently selected from the group consisting of: hydrogen, substituted or unsubstituted C1-C9 alkyl, C1-C4 haloalkyl (such as trifluoromethyl), substituted or unsubstituted C3-C 12 cycloalkyl, and substituted or unsubstituted 4- to 12-membered heterocyclic group; or, R 2A and R 2B together with the carbon atom to which they are attached form a substituted or unsubstituted C3-C 12 cycloalkyl or a substituted or unsubstituted 4- to 12-membered heterocyclic group;

[0019] R 2A and R 2B in which the substitution means that one or more hydrogens in the group are replaced by R 2S and R 2S are each independently selected from the group consisting of: halogen, sulfone, sulfoxide, hydroxyl, carboxyl, C1-C6 alkyl, oxo (=O); or, two R 2S connected to the same atom or adjacent atoms together with the atom to which they are attached form a substituted or unsubstituted C3-C6 cycloalkyl or a substituted or unsubstituted 4- to 6-membered heterocyclic group; in R 2S the substitution means being substituted by one or more substituents selected from the group consisting of: hydrogen, halogen, C1-C4 alkyl, C1-C4 haloalkyl;

[0020] R 2 Selected from the group consisting of hydrogen, halogen, nitro, and cyano.

[0021] In another preferred embodiment, the compound is as shown in Formula A-a

[0022]

[0023] In another preferred embodiment, n1 is 1.

[0024] In another preferred embodiment, n2 is 1.

[0025] In another preferred embodiment, n1, n2, X, R 1 , R 2A , R 2B , R 2S , and R 2 are each independently the corresponding group in the specific compounds in Table A, Table B, or the Examples.

[0026] In another preferred embodiment, the compound is as shown in Formula I;

[0027]

[0028] X is CR 1 or N;

[0029] R 1 is selected from the group consisting of hydrogen, halogen (such as F, Cl, Br, or I), C1-C4 alkyl (such as methyl), C1-C4 haloalkyl (such as trifluoromethyl), C1-C3 alkoxy (-O-C1-C3 alkyl), and C1-C3 alkylthio (-S-C1-C3 alkyl);

[0030] R 2A and R 2B are each independently selected from the group consisting of hydrogen, substituted or unsubstituted C1-C9 alkyl, C1-C4 haloalkyl (such as trifluoromethyl), substituted or unsubstituted C3-C 12 cycloalkyl, and substituted or unsubstituted 4- to 12-membered heterocyclic group; or, R 2A and R 2B together with the carbon atom to which they are attached form a substituted or unsubstituted C3-C 12 cycloalkyl or a substituted or unsubstituted 4- to 12-membered heterocyclic group;

[0031] R 2A and R 2B in which the substitution means that one or more hydrogens in the group are replaced by R 2S and R 2SEach is independently selected from the following group: halogen, sulfone, sulfoxide, hydroxyl, carboxyl, C1-C6 alkyl, oxo (=O); or, two Rs attached to the same atom or adjacent atoms 2S together with the attached atom form a substituted or unsubstituted C3-C6 cycloalkyl or a substituted or unsubstituted 4- to 6-membered heterocyclic group; R 2S wherein, the said substitution means being substituted by one or more substituents selected from the following group: hydrogen, halogen, C1-C4 alkyl, C1-C4 haloalkyl;

[0032] R 2 is selected from the following group: hydrogen, halogen, nitro, cyano.

[0033] In another preferred example, R 1 is selected from the following group: H, halogen (such as F, Cl, Br or I), C1-C4 alkyl.

[0034] In another preferred example, X is CH.

[0035] In another preferred example, R 2A and R 2B at least one of them is not hydrogen.

[0036] In another preferred example, R 2A is selected from the following group: hydrogen, C1-C4 alkyl (such as methyl), R 2B is selected from the following group: substituted or unsubstituted C1-C9 alkyl, C1-C4 haloalkyl (such as trifluoromethyl), substituted or unsubstituted C3-C 12 cycloalkyl and substituted or unsubstituted 4- to 12-membered heterocyclic group; or, R 2A and R 2B and the carbon atom to which they are attached together form a substituted or unsubstituted C3-C 12 cycloalkyl or a substituted or unsubstituted 4- to 12-membered heterocyclic group.

[0037] In another preferred example, R 2A is hydrogen; R 2B is selected from the following group: substituted or unsubstituted C3-C9 alkyl (such as isopropyl, tert-butyl), substituted or unsubstituted C3-C 12 cycloalkyl, and substituted or unsubstituted 4- to 12-membered heterocyclic group.

[0038] In another preferred example, R 2A is C1-C4 alkyl (such as methyl); R 2B is selected from the following group: substituted or unsubstituted C1-C9 alkyl (such as methyl), and C1-C4 haloalkyl (such as trifluoromethyl).

[0039] In another preferred example, R 2A and R 2Band together with the carbon atoms to which they are attached form a substituted or unsubstituted C3-C 12 cycloalkyl group, or a substituted or unsubstituted 4- to 12-membered heterocyclic group.

[0040] In another preferred embodiment, R 2A is hydrogen, and R 2B is selected from the group consisting of: substituted or unsubstituted C4-C9 alkyl groups, substituted or unsubstituted C3-C 12 cycloalkyl groups and substituted or unsubstituted 4- to 12-membered heterocyclic groups.

[0041] In another preferred embodiment, R 2A is hydrogen, and R 2B is selected from the group consisting of: substituted or unsubstituted C3-C 12 cycloalkyl groups and substituted or unsubstituted 4- to 12-membered heterocyclic groups.

[0042] In another preferred embodiment, R 2A is hydrogen, and R 2B is -CH(R 9 )R 10 ; wherein, R 9 , R 10 and the carbon atoms to which they are attached together form a substituted or unsubstituted C3-C 12 cycloalkyl group (preferably, a C4-C 10 cycloalkyl group) and a substituted or unsubstituted 4- to 12-membered heterocyclic group (preferably, a 4- to 10-membered heterocyclic group).

[0043] In another preferred embodiment, the C3-C 12 cycloalkyl group is a C4-C 10 cycloalkyl group.

[0044] In another preferred embodiment, the C3-C 12 cycloalkyl group is selected from: cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

[0045] In another preferred embodiment, the substituted or unsubstituted C3-C 12 cycloalkyl group is selected from the group consisting of

[0046]

[0047] In another preferred embodiment, the 4- to 12-membered heterocyclic group is a 4- to 10-membered heterocyclic group.

[0048] In another preferred embodiment, the 4- to 12-membered heterocyclic group is a saturated 4- to 6-membered heterocyclic group containing 1 or 2 heteroatoms selected from O, S and N.

[0049] In another preferred embodiment, the 4- to 12-membered heterocyclic group is a saturated 6-membered heterocyclic group containing 1 heteroatom selected from O, S and N.

[0050] In another preferred embodiment, the heteroatom is located at the 4-position (para-position) of the 6-membered heterocyclic group.

[0051] In another preferred embodiment, the substituted or unsubstituted 4- to 12-membered heterocyclic group is selected from the group consisting of:

[0052]

[0053] In another preferred embodiment, selected from the group consisting of:

[0054]

[0055] In another preferred embodiment, R 2 is a halogen; preferably, it is Cl.

[0056] In another preferred embodiment, the compound is represented by formula (I-a)

[0057]

[0058] wherein α represents that the carbon atom at this position (i.e., the carbon atom to which R 2A and R 2B are attached) is a chiral carbon atom or an achiral carbon atom; X, R 2A , R 2B and R 2 are as defined in formula I.

[0059] In another preferred embodiment, α represents that the configuration of the carbon atom at this position is R-type, S-type, or (R,S)-type.

[0060] In another preferred embodiment, the compound is represented by formula (I-b) or formula (I-c);

[0061]

[0062] wherein α represents that the carbon atom at this position (i.e., the carbon atom to which R 2A and R 2B are attached) is a chiral carbon atom or an achiral carbon atom, X, R 2A , R 2B and R 2 are as defined in formula I.

[0063] In another preferred embodiment, the pharmaceutically acceptable salt is a salt formed by the compound and an organic acid and / or an inorganic acid. In another preferred embodiment, the organic acid is selected from the group consisting of: p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, benzoic acid, trifluoroacetic acid, acetic acid, citric acid, tartaric acid, gluconic acid, lactic acid, malic acid, stearic acid, valeric acid, nitric acid, oxalic acid, succinic acid, or a combination thereof. In another preferred embodiment, the inorganic acid is selected from the group consisting of: hydrochloric acid, phosphoric acid, sulfuric acid, hydrobromic acid, or a combination thereof.

[0064] In another preferred embodiment, the pharmaceutically acceptable salt is a salt formed by the compound and an organic base and / or an inorganic base. In another preferred embodiment, the organic base is selected from the group consisting of dicyclohexylamine, tri(hydroxyethyl)methylamine, ethylenediamine, ethanolamine, diethanolamine, triethanolamine, piperazine, aminoethanol, imidazole, meglumine, or a combination thereof. In another preferred embodiment, the inorganic base is selected from the group consisting of sodium hydroxide, sodium bicarbonate, sodium carbonate, potassium hydroxide, potassium carbonate, or a combination thereof.

[0065] In another preferred embodiment, X, R 1 , R 2A , R 2B , R 2S , and R 2 are each independently the corresponding group in the specific compounds in Table A, Table B or the Examples.

[0066] In another preferred embodiment, the compound is selected from Table A

[0067] Table A

[0068]

[0069]

[0070]

[0071] In another preferred embodiment, it is selected from Table B: Table B

[0072]

[0073]

[0074]

[0075]

[0076] In a second aspect of the present invention, there is provided a pharmaceutical composition, wherein the composition comprises:

[0077] (a) one or more compounds as described in the first aspect or their pharmaceutically acceptable salts, racemates, tautomers, optical isomers or mixtures of isomers; and

[0078] (b) a pharmaceutically acceptable carrier.

[0079] In another preferred embodiment, the pharmaceutically acceptable carrier includes sugars, starches, cellulose and its derivatives, gelatin, talc, solid lubricants, vegetable oils, polyols, emulsifiers, wetting agents, coloring agents, flavoring agents, stabilizers, antioxidants, preservatives and pyrogen-free water, excipients.

[0080] In another preferred embodiment, the pharmaceutical composition further comprises a glidant or a diluent.

[0081] In a third aspect of the present invention, there is provided the use of a compound as described in the first aspect or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomeric mixture thereof, or a pharmaceutical composition as described in the second aspect in the preparation of a medicament for the treatment or prevention of infectious diseases caused by pathogenic bacteria.

[0082] In another preferred embodiment, the pathogenic bacteria are Gram-negative bacteria.

[0083] In another preferred embodiment, the Gram-negative bacteria include: Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii.

[0084] In another preferred embodiment, the pathogenic bacteria are sensitive pathogenic bacteria or drug-resistant pathogenic bacteria.

[0085] In another preferred embodiment, the pathogenic bacteria are drug-resistant pathogenic bacteria

[0086] In another preferred embodiment, the pathogenic bacteria are selected from the group consisting of: Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii.

[0087] In a fourth aspect of the present invention, there is provided a method for inhibiting or killing pathogenic bacteria, comprising the step of contacting the pathogenic bacteria with a compound as described in the first aspect or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomeric mixture thereof, or contacting with a pharmaceutical composition as described in the second aspect, thereby inhibiting or killing the pathogenic bacteria.

[0088] In another preferred embodiment, the pathogenic bacteria are as defined above.

[0089] In another preferred embodiment, the method is non-therapeutic in vitro.

[0090] In another preferred embodiment, the method is therapeutic or prophylactic.

[0091] In a fifth aspect of the present invention, there is provided a method for treating and / or preventing infectious diseases caused by pathogenic bacteria, wherein the method comprises the steps of:

[0092] administering to a subject in need a compound as described in the first aspect or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture thereof, or administering a pharmaceutical composition as described in the second aspect.

[0093] In another preferred example, the subject includes a human or a non-human mammal.

[0094] In a sixth aspect of the present invention, there is provided a method for preparing a compound as described in the first aspect; wherein the compound is as shown in formula I-a; and the method comprises the steps of:

[0095] (1) Reacting intermediate In-1 with intermediate In-2 to obtain intermediate In-3; and

[0096] (2) Deprotecting intermediate In-3 to obtain a compound as shown in formula I;

[0097]

[0098] wherein R 2A 、R 2B 、R 2 and X are as defined in formula I; R a1 and R a2 are carboxyl protecting groups; R b is an amino protecting group.

[0099] In another preferred example, the carboxyl protecting groups are each independently selected from the group consisting of p-methoxybenzyl, diphenylmethyl, trityl and tert-butyl ester groups.

[0100] In another preferred example, the amino protecting group is selected from the group consisting of p-methoxybenzyl, diphenylmethyl, trityl and tert-butyl ester groups.

[0101] It should be understood that within the scope of the present invention, the above technical features of the present invention and the technical features specifically described below (such as in the examples) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be repeated one by one here. Detailed Description of the Invention

[0102] Through long-term and in-depth efforts, the present inventors unexpectedly found that replacing the special quaternary ammonium salt structure of the side chain of cefiderocol with -S not only improves the stability of the compounds of the present invention, but also significantly enhances the antibacterial activity against Gram-negative bacteria compared with cefiderocol. In addition, the applicant also unexpectedly found that When there are large groups (such as rings or groups containing 3 or more carbon atoms) present, the antibacterial activity can be further enhanced. Based on this, the inventors completed the present invention.

[0103] The term

[0104] In this article, unless otherwise specified, each abbreviation or term has the meaning well-known to those skilled in the art.

[0105] As used herein, the wavy line ( ) on the chemical bond in the group structural formula represents the position connected to other parts of the compound.

[0106] As used herein, "halogen" refers to F, Cl, Br, and I. More preferably, the halogen atom is selected from F, Cl, and Br.

[0107] As used herein, Ca-Cb before a group (such as an alkyl group) means that the group has a to b carbon atoms. For example, C1-C4 means that the group contains 1, 2, 3, or 4 carbon atoms. Similarly, C1-C3, C1-C6, C1-C9, C3-C9 respectively mean containing 1, 2, or 3 carbon atoms, containing 1, 2, 3, 4, 5, or 6 carbon atoms, containing 1, 2, 3, 4, 5, 6, 7, 8, or 9 carbon atoms, containing 3, 4, 5, 6, 7, 8, or 9 carbon atoms.

[0108] As used herein, the term "alkyl" itself or as part of another substituent refers to a straight-chain or branched-chain alkyl group having the specified number of carbon atoms. For example, a C1-C4 alkyl group refers to a straight-chain or branched-chain alkyl group containing 1-4 carbon atoms. Examples of alkyl groups include, for example, methyl, ethyl (Et), propyl, isopropyl, butyl, isobutyl, tert-butyl, or similar groups.

[0109] As used herein, the term "haloalkyl" refers to a group in which one or more hydrogens in the alkyl group are replaced by a halogen. Examples of haloalkyl groups include, for example, trifluoromethyl.

[0110] As used herein, the term "cycloalkyl" refers to a hydrocarbon ring having the specified number of ring carbon atoms (for example, C3-C 12 cycloalkyl), and is completely saturated or has no more than one double bond between the ring tops. "Cycloalkyl" also refers to bicyclic and polycyclic hydrocarbon rings. Examples of alkyl groups include, for example, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl, etc.

[0111] As used herein, the term "heterocyclic group" refers to a cycloalkyl group having a specified number of ring atoms and containing 1 to 5 (preferably 1 or 2) heteroatoms selected from N, O, and S, wherein the nitrogen and sulfur atoms are optionally oxidized (such as to -SO- and -SO2-), and the nitrogen atom is optionally quaternized. The heterocyclic group can be a monocyclic, bicyclic, or polycyclic system. Non-limiting examples of heterocycloalkyl groups include pyrrolidine, imidazolidine, pyrazolidine, butyrolactam, valerolactam, tetrahydrofuran, tetrahydrothiophene, quinuclidine, and the like. The heterocycloalkyl group can be attached to the rest of the molecule through a ring carbon or a heteroatom.

[0112] As used herein, the term "heteroatom" is intended to include oxygen (O), nitrogen (N), and sulfur (S).

[0113] As used herein, alkoxy means -O-alkyl, wherein the alkyl is as defined above.

[0114] As used herein, alkylthio means -S-alkyl, wherein the alkyl is as defined above.

[0115] In this document, unless otherwise specified, the term "substituted" means that one or more hydrogen atoms on a group are replaced by a substituent selected from the group consisting of: halogen, unsubstituted or halogenated C1-C6 alkyl (such as methyl, ethyl, trifluoromethyl, etc.).

[0116] As used herein, the terms "comprising", "including", or "containing" mean that the various components can be applied together in the mixtures or compositions of the present invention. Thus, the terms "consisting essentially of" and "consisting of" are included in the term "comprising".

[0117] As used herein, the term "pharmaceutically acceptable" ingredient means a substance that is suitable for use in humans and / or animals without excessive adverse side effects (such as toxicity, irritation, and allergic reactions), i.e., a substance having a reasonable benefit / risk ratio.

[0118] As used herein, the term "pharmaceutically acceptable salt" refers to salts of the compounds of the present invention formed with acids or bases that are suitable for use as pharmaceuticals. Pharmaceutically acceptable salts include inorganic salts and organic salts. A preferred class of salts are salts of the compounds of the present invention formed with acids. Acids suitable for forming salts can be organic acids or inorganic acids. Examples of organic acids include, but are not limited to: p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, benzoic acid, trifluoroacetic acid, acetic acid, citric acid, tartaric acid, gluconic acid, lactic acid, malic acid, stearic acid, valeric acid, nitric acid, oxalic acid, succinic acid, and the like. Examples of inorganic acids include, but are not limited to: hydrochloric acid, phosphoric acid, sulfuric acid, hydrobromic acid, or combinations thereof. Another preferred class of salts are salts of the compounds of the present invention formed with bases. Bases suitable for forming salts can be organic bases or inorganic bases. Examples of organic bases include, but are not limited to: dicyclohexylamine, tris(2-hydroxyethyl)methylamine, ethylenediamine, ethanolamine, diethanolamine, triethanolamine, piperazine, aminoethanol, imidazole, glucosamine, and the like. Examples of inorganic bases include, but are not limited to: sodium hydroxide, sodium bicarbonate, sodium carbonate, potassium hydroxide, potassium carbonate, and the like.

[0119] Unless otherwise specified, certain compounds of the present invention possess asymmetric carbon atoms (optical centers) or double bonds; racemates, diastereomers, geometric isomers, regioisomers, and individual isomers (e.g., isolated enantiomers) are all intended to be included within the scope of the present invention. When the compounds provided herein have a defined stereochemistry (represented as R or S, or with dashed or wedged bonds indicating), those compounds will be understood by those skilled in the art to be substantially free of other isomers (e.g., at least 80%, 90%, 95%, 98%, 99% and up to 100% free of other isomers).

[0120] The present invention also provides compounds in prodrug form. Prodrugs of the compounds described herein are those compounds that readily undergo chemical change under physiological conditions to provide the compounds of the present invention. Additionally, prodrugs can be converted to the compounds of the present invention by chemical or biochemical means in an ex vivo environment. For example, a prodrug can be slowly converted to the compound of the present invention when placed in a transdermal patch reservoir containing a suitable enzyme or chemical reagent.

[0121] Certain compounds of the present invention can exist in unsolvated forms as well as solvated forms, including hydrated forms. Solvated forms are generally equivalent to unsolvated forms and are intended to be included within the scope of the present invention. Certain compounds of the present invention can exist in polymorphic or amorphous forms. Generally, for the applications contemplated by the present invention, all physical forms are equivalent and are intended to be included within the scope of the present invention.

[0122] The compounds of the present invention may also contain unnatural proportions of atomic isotopes at one or more of the isotopic atoms that make up such compounds. An unnatural proportion of an isotope can be defined as the amount from the naturally found amount of the atom in question to 100% of that atom. For example, the compounds may be incorporated with radioactive isotopes such as tritium ( 3 H), iodine-125 ( 125 I), or carbon-14 ( 14 C), or non-radioactive isotopes such as deuterium ( 2 H) or carbon-13 ( 13 C). In addition to the uses described herein, such isotopic variants may provide additional uses. For example, isotopic variants of the compounds of the present invention may have additional uses, including but not limited to as diagnostic and / or imaging reagents, or as cytotoxic / radiotoxic therapeutic agents. Additionally, isotopic variants of the compounds of the present invention may have altered pharmacokinetic and pharmacodynamic characteristics, thereby contributing to increased safety, tolerance, or efficacy during treatment. All isotopic variants of the compounds of the present invention, whether radioactive or not, should be included within the scope of the present invention.

[0123] Cephalosporin-siderophore conjugate

[0124] As used herein, the term "compounds of the present invention" or "cephalosporin-siderophore conjugates of the present invention" refers to compounds represented by Formula A, Formula I, Formula A-a, Formula I-a, Formula I-b, or Formula I-c. The term also includes various crystalline forms, pharmaceutically acceptable salts, hydrates or solvates of the compounds of Formula A, Formula I, Formula A-a, Formula I-a, Formula I-b, or Formula I-c, or mixtures of their respective isomers and isomers.

[0125] An object of the present invention is to provide a cephalosporin-siderophore conjugate (which may also be referred to as the compound of the present invention) for the treatment of infectious diseases caused by Gram-negative bacteria, particularly including infections caused by sensitive and drug-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii.

[0126] In a specific embodiment of the present invention, there is provided a cephalosporin-siderophore conjugate represented by General Formula (A) or (I), or its racemate, tautomer, optical isomer, or its pharmaceutically acceptable salt;

[0127]

[0128] wherein each variable is defined as in the first aspect.

[0129] In another aspect of the present invention, there is provided a cephalosporin-siderophore conjugate represented by General Formula (I-a), or its racemate, tautomer, optical isomer, or its pharmaceutically acceptable salt:

[0130]

[0131] Wherein, each variable is defined as in the first aspect.

[0132] In another embodiment, X is independently selected from N or CR 1 ; R 1 is independently selected from hydrogen, halogen, C1-C4 alkyl, trifluoromethyl; C1-C3 alkoxy, C1-C3 alkylthio.

[0133] In another embodiment, R 2A and R 2B are independently selected from hydrogen, trifluoromethyl, substituted or unsubstituted C1-C9 alkyl, substituted or unsubstituted C3-C 12 cycloalkyl, substituted or unsubstituted C4-C 12 heterocyclic group, and the substituents are halogen, sulfone, sulfoxide, hydroxyl, carboxyl, C1-C6 alkyl; provided that R 2A and R 2B are not both hydrogen at the same time;

[0134] R 2A and R 2B Preferably:

[0135]

[0136] In another embodiment, the stereoconfiguration of the α-carbon atom is R, S or (R,S).

[0137] In another embodiment, the stereoconfiguration of the carbon atom to which R 2A and R 2B are attached is R, S or (R,S).

[0138] In another embodiment, R 2 is selected from halogen, hydrogen, nitro, cyano; preferably: chlorine, fluorine, bromine.

[0139] In another embodiment, the compound is represented by the general formula (I-b):

[0140]

[0141] Wherein, R 2A , R 2B , R 2 , X are defined as described above;

[0142] In another preferred example, the compound is represented by the general formula (I-c):

[0143]

[0144] Wherein, R2A , R 2B , R 2 , the definitions of X are as described above;

[0145] In another embodiment, the pharmaceutically acceptable salts are selected from salts formed by the compound and a suitable equivalent of an organic acid or an inorganic acid. The organic acids are selected from: p-toluenesulfonic acid, benzenesulfonic acid, methanesulfonic acid, benzoic acid, trifluoroacetic acid, acetic acid, citric acid, tartaric acid, malic acid, gluconic acid, lactic acid, malic acid, stearic acid, valeric acid, nitric acid, oxalic acid, succinic acid; The inorganic acids are selected from hydrochloric acid, phosphoric acid, sulfuric acid, hydrobromic acid.

[0146] In another preferred embodiment, the pharmaceutically acceptable salts are selected from salts formed by the compound and a suitable equivalent of an organic base or an inorganic base. The organic bases include but are not limited to dicyclohexylamine, tri(hydroxyethyl)methylamine, ethylenediamine, ethanolamine, diethanolamine, triethanolamine, piperazine, aminoethanol, imidazole, glucosamine; The inorganic bases include but are not limited to sodium hydroxide, sodium bicarbonate, sodium carbonate, potassium hydroxide, potassium carbonate.

[0147] In another preferred embodiment, the compound is selected from Table A.

[0148] In another preferred embodiment, the compound, its tautomer, optical isomer or a mixture thereof, or its pharmaceutically acceptable salt is selected from Table B.

[0149] In another preferred embodiment, the cephalosporin-siderophore conjugate, its tautomer, optical isomer or a mixture thereof, or its pharmaceutically acceptable salt, may preferably be the following compounds:

[0150]

[0151]

[0152]

[0153]

[0154]

[0155] Preparation method of the compounds of the present invention

[0156] The preparation method of the compounds of the present invention will be described more specifically below. The conditions of this preparation method, such as reactants, solvents, acids, bases, amounts of compounds used, reaction temperature, reaction time, etc. are not limited to the following description. Those skilled in the art to which the present invention pertains can easily combine various synthesis methods described in this specification or known to those skilled in the art to conveniently prepare the compounds of the present invention.

[0157] In some specific embodiments, a preferred preparation method of the compound of the present invention or its pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture is provided as follows.

[0158] Synthesis of the compound of the present invention

[0159] Preferably, the compound of the present invention can be synthesized according to Route 1, 2, 3 or 4 shown below.

[0160] Route 1:

[0161]

[0162] Wherein, R 2A , R 2B , R 2 , X are defined as described above; wherein R a1 , R a2 are carboxyl protecting groups, and the protecting groups are independently preferably selected from: p-methoxybenzyl, diphenylmethyl, triphenylmethyl, tert-butyl ester group; R b is an amino protecting group, preferably, the protecting group is selected from: p-methoxybenzyl, diphenylmethyl, triphenylmethyl, tert-butyl ester group; The synthesis of N1 has been reported in the literature.

[0163] Optionally, Step 1 of Route 1 includes: reacting intermediate A1 in a suitable anhydrous solvent under inert gas protection and basic conditions to obtain intermediate A2. Preferably, the solvent is selected from: tetrahydrofuran (THF), diethyl ether, dichloromethane (DCM), toluene, acetonitrile (ACN), N,N-dimethylformamide (DMF), or a combination thereof; and / or, the base can be selected from but not limited to: potassium carbonate, sodium carbonate, sodium hydride, or a combination thereof.

[0164] Optionally, Step 2 of Route 1 includes: performing a Gabriel reaction on intermediate A2 with ammonia or a primary amine reagent; preferably, the primary amine reagent is selected from: hydrazine monohydrate (NH2-NH2.H2O).

[0165] Optionally, Step 3 of Route 1 includes: first performing an addition reaction on intermediate A3 with N1, and then performing an elimination reaction to generate a compound A4 containing an oxime ether structure.

[0166] Optionally, Step 4 of Route 1 includes: reacting intermediate A4 with intermediate M1 under a condensing agent and an organic base or inorganic base condition, using a polar aprotic solvent as the solvent at -30 to 0 °C (such as -15 °C) for 1-4 h to obtain intermediate A5.

[0167] Optionally, the condensing agent may be selected from: 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI·HCl), 1-hydroxybenzotriazole (HOBT), and tetramethylchlorouronium hexafluorophosphate (TCFH), or a combination thereof; and / or, the organic base may be selected from: triethylamine, diisopropylethylamine (DIPEA), and N-methylimidazole, or a combination thereof; and / or, the inorganic base may be selected from sodium bicarbonate, sodium carbonate, potassium bicarbonate, or a combination thereof; and / or, the polar aprotic solvent may be, for example: dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), acetonitrile (ACN), and dichloromethane (DCM), or a combination thereof.

[0168] Optionally, step 5 of Route 1 includes: subjecting intermediate A5 to a nucleophilic substitution reaction in a polar aprotic solvent, using an iodide salt as a catalyst, under conditions of an organic base or an inorganic base; preferably, the polar aprotic solvent is: tetrahydrofuran (THF), N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), acetone, or a combination thereof; and / or, the iodide salt includes but is not limited to: sodium iodide, potassium iodide, or a combination thereof; and / or, the organic base includes but is not limited to: triethylamine, N,N-diisopropylethylamine (DIPEA), or a combination thereof; and / or, the inorganic base includes but is not limited to sodium bicarbonate, sodium carbonate, potassium bicarbonate, or a combination thereof.

[0169] Optionally, step 6 of Route 1 includes: subjecting intermediate A6 to acid deprotection in a nonpolar solvent in the presence of a cation scavenger to obtain compound A7 (i.e., the compound of formula I in the present application); preferably, the nonpolar solvent may be, for example, dichloromethane (DCM); and / or, the cation scavenger includes but is not limited to triethylsilane, trimethylsilane, or a combination thereof; and / or, the acid includes but is not limited to: trifluoroacetic acid (TFA).

[0170] Route 2:

[0171]

[0172] Wherein, R 2B 、R 2 、R a1 、R a2 、R b 、X are defined as described above, R 2A =H (R 2A is not shown in some intermediates); The synthesis of N1 has been reported in the literature.

[0173] Optionally, step 1 of Route 2 includes: subjecting carbonyl intermediate B1 to an asymmetric addition reaction with a silylating agent under the action of a Lewis acid to synthesize cyanated silyl ether intermediate B2; preferably, the solvents used include but are not limited to: dichloromethane (DCM), tetrahydrofuran (THF), or a combination; and / or, the silylating agent includes but is not limited to: trimethylcyanosilane (TMSCN); and / or, the Lewis acid includes but is not limited to: lithium chloride (LiCl), zinc iodide (ZnI2), titanium tetrachloride (TiCl4), or a combination.

[0174] Optionally, step 2 of Route 2 includes: subjecting intermediate B2 to deprotection of the silyl ether under acidic conditions to synthesize cyanohydrin intermediate B3; preferably, the conditions for silyl ether deprotection are: in the presence of tetraalkylammonium fluoride (such as tetrabutylammonium fluoride) or under acidic conditions (such as hydrochloric acid solution, dilute sulfuric acid solution, etc.).

[0175] Optionally, step 3 of Route 2 includes: heating and refluxing intermediate B3 in an alcohol solution containing hydrochloric acid at 70 - 90 °C (such as 80 °C) overnight to obtain intermediate B4; preferably, the alcohol solution of hydrochloric acid is: hydrochloric acid methanol solution, hydrochloric acid ethanol solution, or a combination thereof.

[0176] Optionally, step 4 of Route 2 includes: hydrolyzing intermediate B4 under basic conditions to obtain B5, preferably, the bases include but are not limited to: sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, or a combination thereof.

[0177] Optionally, step 5 of Route 2 includes: reacting intermediate B5 with diazomethane to obtain carboxylic acid methyl ester intermediate B6; wherein, R a1 is a carboxyl protecting group, preferably the carboxyl protecting group can be selected from but is not limited to: p-methoxybenzyl, diphenylmethyl, triphenylmethyl, tert-butyl ester group.

[0178] Optionally, step 6 of Route 2 includes: subjecting intermediate B6 to a Mitsunobu reaction under an inert gas and anhydrous conditions to obtain intermediate B7, preferably, the solvents are selected from: tetrahydrofuran (THF), diethyl ether, dichloromethane (DCM), toluene, ethyl acetate (EA), acetonitrile (ACN), N,N-dimethylformamide (DMF), or a combination thereof; and / or, the phosphorus ligand is selected from: triphenylphosphine (PPh3), tributylphosphine (P(n-Bu)3), or a combination thereof; and / or, the azodicarboxylate includes but is not limited to: diethyl azodicarboxylate (DEAD) and diisopropyl azodicarboxylate (DIAD), or a combination thereof.

[0179] Optionally, step 7 of Route 2 includes: subjecting intermediate B7 to a Gabriel reaction with ammonia or a primary amine reagent; preferably, the primary amine reagent is selected from: hydrazine monohydrate (NH2-NH2.H2O).

[0180] Optionally, step 8 of Route 2 includes: first subjecting intermediate B8 to an addition reaction with N1, and then to an elimination reaction to form intermediate B9 containing an oxime ether structure.

[0181] Optionally, step 9 of Route 2 includes: reacting intermediate B9 with M1 in the presence of a condensing agent and an organic base or an inorganic base, using a polar aprotic solvent as the solvent, and reacting at -15 °C for 1 - 4 h to obtain intermediate B10;

[0182] Optionally, the condensing agent may be selected from: 2-(7-azabenzotriazol-1-yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI·HCl), 1-hydroxybenzotriazole (HOBT), and tetramethylchlorouronium hexafluorophosphate (TCFH), or a combination thereof; and / or, the organic base may be selected from: triethylamine, diisopropylethylamine (DIPEA), and N-methylimidazole, or a combination thereof; and / or, the inorganic base may be selected from sodium bicarbonate, sodium carbonate, potassium bicarbonate, or a combination thereof; and / or, the polar aprotic solvent may be, for example: dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), acetonitrile (ACN), and dichloromethane (DCM), or a combination thereof.

[0183] Optionally, step 10 of Route 2 includes: subjecting intermediate B10 to a nucleophilic substitution reaction in a polar aprotic solvent, using an iodide salt as a catalyst, and under the condition of an organic base or an inorganic base; preferably, the polar aprotic solvent is preferably: tetrahydrofuran (THF), N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), acetone, or a combination thereof; and / or, the iodide salt includes but is not limited to: sodium iodide, potassium iodide, or a combination thereof; and / or, the organic base includes but is not limited to: triethylamine, N,N-diisopropylethylamine (DIPEA), or a combination thereof; and / or, the inorganic base includes but is not limited to sodium bicarbonate, sodium carbonate, potassium bicarbonate, or a combination thereof.

[0184] Optionally, step 11 of Route 2 includes: subjecting intermediate B11 to acid deprotection in a non-polar solvent in the presence of a cation scavenger to obtain compound B12 (i.e., the compound of formula I in the present application, where R 2A = H); preferably, the non-polar solvent may be, for example, dichloromethane (DCM); and / or, the cation scavenger includes but is not limited to triethylsilane, trimethylsilane, or a combination thereof; the acid includes but is not limited to: trifluoroacetic acid (TFA).

[0185] Route 3:

[0186]

[0187] Among them, R 2A and R 2B and R 2 and R a1 and R a2 and R b and N1 are defined as described above.

[0188] Optionally, step 1 of Route 3 includes: reacting C1 with an amination reagent under alkaline conditions to form a hydroxylamine compound C2; preferably, the solvent is preferably: tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dichloromethane (DCM), or a combination thereof; and / or, the base includes but is not limited to: sodium tert-butoxide, potassium tert-butoxide, sodium hydride, or a combination thereof; and / or, the amination reagent is preferably: 2-[(aminooxy)sulfonyl]-1,3,5-trimethylbenzene, diphenylphosphorylhydroxylamine.

[0189] Optionally, steps 2-5 of Route 3 are the same as the steps for preparing intermediate A3 to compound A7 in Route 1

[0190] Route 4:

[0191]

[0192] Among them, R 9 and R 10 together with the carbon atoms to which they are attached form a substituted or unsubstituted C3-C 12 cycloalkyl (such as C4-C 10 cycloalkyl), or a substituted or unsubstituted 4- to 12-membered heterocyclic group such as (4- to 10-membered heterocyclic group), and the substituents are R 2S as defined above, preferably halogen, CF3, sulfone, sulfoxide, hydroxyl, carboxyl, C1-C6 alkyl; R 2 , X, and N1 are defined as described above.

[0193] Optionally, step 1 of Route 4 includes: carrying out a Wittig reaction on intermediate D1 with a triaryl or trialkyl phosphine in the presence of an organic base or an inorganic base in an anhydrous and anaerobic system to form an E / Z enol ether intermediate D2; preferably, the solvent includes but is not limited to: tetrahydrofuran (THF), diethyl ether, dimethyl ether (DME), methyl tert-butyl ether (MTBE), dioxane, N,N-dimethylformamide (DMF) or toluene, or a combination thereof; and / or, the triaryl or trialkyl phosphine includes but is not limited to: methoxymethyltriphenylphosphonium chloride, triphenylphosphine, methylenetriphenylphosphine, or a combination thereof; and / or, the inorganic base includes but is not limited to: sodium hydride, sodium ethoxide, or a combination thereof; and / or, the organic base includes but is not limited to: tert-butyllithium, n-butyllithium or phenyllithium, or a combination thereof.

[0194] Optionally, steps 2-3 of Route 4 include: generating a keto-enol tautomeric enol intermediate D3 and its aldehyde intermediate D4 from intermediate D2 under organic acid or inorganic acid conditions; preferably, the solvents include but are not limited to: tetrahydrofuran (THF), 1,4-dioxane, water, toluene, acetonitrile (ACN), or combinations thereof; and / or, the organic acids include but are not limited to: formic acid, trifluoroacetic acid, trichloroacetic acid, or combinations thereof; and / or, the inorganic acid is preferably: hydrochloric acid.

[0195] Optionally, steps 4-14 of Route 4 can be synthesized in a similar manner to the steps in Route 2 using the corresponding intermediates as raw materials to obtain the compound of formula I (where R 2A =H, R 2B =-CH(R 9 )R 10 ).

[0196] Chiral synthesis or resolution of the compounds of the present invention:

[0197] The compounds of the present invention can be subjected to chiral synthesis or resolution through the following preferred Route 5. Wherein X, R 2A , R 2B , R 2 , R a1 , R a2 , R b , N1 are defined as described above.

[0198] Route 5:

[0199]

[0200] Optionally, step 1 of Route 5 includes: reacting intermediate B6 in a non-polar solvent under low temperature conditions with a chiral catalyst and a base to selectively form an ester with an acid anhydride, simultaneously obtaining F1 and F2; preferably, the solvents used include but are not limited to: diethyl ether, toluene, dichloromethane (DCM), or combinations thereof; and / or, the chiral catalyst is preferably: (2R)-2,3-dihydro-2-phenylimidazo[2,1-b]benzothiazole, and / or, the bases include but are not limited to: triethylamine, diisopropylethylamine (DIPEA); and / or, the acid anhydrides include but are not limited to: diphenylacetic anhydride, benzoic anhydride, p-toluic anhydride, triphenylacetic anhydride, or combinations thereof.

[0201] Optionally, step 2 of Route 5 includes: hydrolyzing intermediate F2 under basic conditions to obtain intermediate F3; preferably, the bases include but are not limited to: sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, lithium hydroxide, or combinations thereof.

[0202] Optionally, steps 3-15 of Route 5 can be synthesized using the corresponding intermediates as starting materials in a manner similar to the steps in Route 2.

[0203] Alternatively, the key intermediate can be synthesized via the following Route 6:

[0204] Route 6:

[0205]

[0206] Optionally, step 1 of Route 6 includes: reacting intermediate F4 with an amination reagent under basic conditions to form hydroxylamine intermediate F12, with the stereoconfiguration of the reaction F12 remaining unchanged; or reacting intermediate F1 with an amination reagent under basic conditions to form hydroxylamine intermediate F6, with the stereoconfiguration of the reaction F6 remaining unchanged; preferably, the solvent is: tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dichloromethane (DCM), or a combination thereof; and / or, the base includes but is not limited to: sodium tert-butoxide, potassium tert-butoxide, sodium hydride, or a combination thereof; and / or, the amination reagent is: 2-[(aminooxy)sulfonyl]-1,3,5-trimethylbenzene, diphenylphosphorylhydroxylamine, or a combination thereof;

[0207] A preferred method for preparing the pharmaceutically acceptable salts of the compounds of the present invention is as follows:

[0208] Preparing acid salts:

[0209] The acid salts of the compounds of the present invention can be prepared via Route 7 as shown below:

[0210]

[0211] Optionally, it includes the steps of: dissolving the trifluoroacetate salt of the compound of formula (I) in appropriate water and stirring for 15-20 min under an ice bath. After filtration, a solid powder is obtained and dried in vacuo at 28 °C for 24-48 h to obtain the corresponding inner salt. The residual amount of trifluoroacetate is detected by ion chromatography, and the absence of the fluorine peak of trifluoroacetic acid is confirmed by 19F NMR spectroscopy.

[0212] Separately, dissolve the inner salt of the obtained compound in an appropriate solvent, add 1 equivalent of acid, or dissolve 1 equivalent of acid in the same solvent and then add the acid solution dropwise to the solution of the compound of formula (I), and stir for 10-20 min. After filtration, a solid powder is obtained (or a powder is obtained after freeze-drying). Suspend the obtained powder in methyl tert-butyl ether, slurry for 15-30 min, filter, and dry to obtain the corresponding salt.

[0213] Preferably, the acid selected is as described above; and / or, the solvents used include, but are not limited to: acetonitrile, acetone, ethyl acetate, dichloromethane, tetrahydrofuran, methanol, ethanol, isopropanol, 1,4-dioxane, chloroform, ether, or combinations thereof.

[0214] Preparation of basic salts:

[0215] Monosodium salt:

[0216] The monosodium salt of the compound of the present invention can be prepared by Route 8 as shown below:

[0217]

[0218] Optionally, Route 8 includes the steps of: dissolving Compound H in a suitable solvent, dropping 1 equivalent of a base solution, and stirring for 3 - 4 min. Concentrate the solvent, add an appropriate amount of deionized water, and vacuum freeze-dry for 12 h to obtain the corresponding salt (white fluffy solid). Protect the solid under argon and store it in the dark at -20°C. Preferably, the solvents used include, but are not limited to: water, acetonitrile, acetone, ethyl acetate, dichloromethane, tetrahydrofuran, methanol, ethanol, isopropanol, 1,4-dioxane, chloroform, ether, or combinations thereof.

[0219] Disodium salt:

[0220] The monosodium salt of the compound of the present invention can be prepared by Route 9 as shown below:

[0221]

[0222] Optionally, Route 9 includes the steps of: dissolving Compound H in a suitable solvent, dropping 2 equivalents of a base solution, and stirring for 2 - 4 min. Concentrate the solvent, add an appropriate amount of deionized water, and vacuum freeze-dry for 12 h to obtain the corresponding salt (off-white fluffy solid). Protect the solid under argon and store it in the dark at -20°C. Preferably, the solvents include, but are not limited to: water, acetonitrile, acetone, ethyl acetate, dichloromethane, tetrahydrofuran, methanol, ethanol, isopropanol, 1,4-dioxane, chloroform, ether.

[0223] Pharmaceutical compositions and methods of administration

[0224] Due to the excellent antibacterial activity of the compounds of the present invention (especially the antibacterial activity against drug-resistant Gram-negative bacteria), the compounds of the present invention and their various crystal forms, pharmaceutically acceptable inorganic or organic salts, hydrates or solvates, racemates, tautomers, optical isomers or mixtures of isomers, and pharmaceutical compositions containing the compounds of the present invention as the main active ingredient can be used for the treatment, prevention, and alleviation of infectious diseases caused by pathogenic bacteria. According to the prior art, the compounds of the present invention can be used for the treatment, prevention, and alleviation of the following diseases: infections caused by Gram-negative bacteria, especially including infectious diseases caused by sensitive and multi-drug resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii.

[0225] In a specific embodiment, a pharmaceutical composition is provided, comprising: (a) one or more of the cephalosporin-siderophore conjugates of the present invention as described above, or their tautomers, optical isomers, or pharmaceutically acceptable salts thereof as active ingredients, and (b) a pharmaceutically acceptable carrier.

[0226] The pharmaceutical composition of the present invention contains the compound of the present invention or its pharmacologically acceptable salt and a pharmacologically acceptable excipient or carrier within a safe and effective amount range. The "safe and effective amount" refers to: an amount of the compound sufficient to significantly improve the condition without causing serious side effects. Generally, the pharmaceutical composition contains 100 - 4000 mg of the compound of the present invention per dose, more preferably, 500 - 2000 mg of the compound of the present invention per dose. The "per dose" is the amount for one injection. The compound of the present invention can be administered 1 - 6 times a day, and a more preferred option is 2 - 3 times a day. When the compound of the present invention is used in the clinical treatment of bacterial infectious diseases, the dose per administration and the frequency of administration per day can be adjusted according to the actual clinical situation to achieve the best therapeutic effect.

[0227] "Pharmaceutically acceptable carrier" refers to: one or more compatible solid or liquid fillers or gelling substances that are suitable for human use and must have sufficient purity and sufficiently low toxicity. "Compatible" herein means that the components in the composition can be blended with the compounds of the present invention and with each other without significantly reducing the efficacy of the compounds. Some examples of pharmaceutically acceptable carriers are cellulose and its derivatives (such as sodium carboxymethylcellulose, sodium ethylcellulose, cellulose acetate, etc.), gelatin, talc, solid lubricants (such as stearic acid, magnesium stearate), calcium sulfate, vegetable oils (such as soybean oil, sesame oil, peanut oil, olive oil, etc.), polyhydric alcohols (such as propylene glycol, glycerol, mannitol, sorbitol, etc.), emulsifiers (such as ) wetting agents (such as sodium dodecyl sulfate), coloring agents, flavoring agents, stabilizers, antioxidants, preservatives, pyrogen-free water, etc. Preferably, the pharmaceutically acceptable carriers include sugars, starches, cellulose and its derivatives, gelatin, talc, solid lubricants, vegetable oils, polyols, emulsifying agents, wetting agents, coloring agents, flavoring agents, stabilizers, antioxidants, preservatives, pyrogen-free water, excipients. In another preferred embodiment, the pharmaceutical composition further comprises a glidant or a diluent.

[0228] There is no particular limitation on the administration mode of the compounds or pharmaceutical compositions of the present invention. Representative administration modes include (but are not limited to): oral, intratumoral, rectal, parenteral (intravenous, intramuscular or subcutaneous), and topical administration.

[0229] Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In these solid dosage forms, the active compound is admixed with at least one conventional inert excipient (or carrier), such as sodium citrate or calcium phosphate, or admixed with the following components: (a) fillers or extenders, for example, starch, lactose, sucrose, glucose, mannitol and silicic acid; (b) binders, for example, hydroxypropylmethyl cellulose, alginate, gelatin, polyvinylpyrrolidone, sucrose and acacia; (c) humectants, for example, glycerol; (d) disintegrants, for example, agar, calcium carbonate, potato starch or tapioca starch, alginic acid, certain complex silicates, and sodium carbonate; (e) solubilizers, for example, paraffin wax; (f) absorption accelerators, for example, quaternary ammonium compounds; (g) wetting agents, for example, cetyl alcohol and glyceryl monostearate; (h) adsorbents, for example, kaolin; and (i) lubricants, for example, talc, calcium stearate, magnesium stearate, solid polyethylene glycol, sodium dodecyl sulfate, or mixtures thereof. In capsules, tablets and pills, the dosage form may also contain buffering agents.

[0230] Solid dosage forms such as tablets, dragees, capsules, pills and granules can be prepared with coatings and casings, such as enteric coatings and other materials well known in the art. They may contain opacifying agents, and the release of the active compound or compounds in such compositions may be delayed in a manner such that it is released in a certain part of the digestive tract. Examples of embedding components that can be used are polymeric materials and waxes. If necessary, the active compound can also be in the form of microcapsules with one or more of the above excipients.

[0231] Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups or tinctures. In addition to the active compound, the liquid dosage forms may contain inert diluents conventionally used in the art, such as water or other solvents, solubilizers and emulsifying agents, for example, ethanol, isopropanol, ethyl carbonate, ethyl acetate, propylene glycol, 1,3-butanediol, dimethylformamide, and oils, especially cottonseed oil, peanut oil, corn germ oil, olive oil, castor oil and sesame oil or mixtures of these substances, etc.

[0232] In addition to these inert diluents, the composition may also contain adjuvants such as wetting agents, emulsifying agents and suspending agents, sweeteners, flavoring agents and fragrances.

[0233] In addition to the active compound, the suspension may contain suspending agents such as ethoxylated isooctadecanol, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum methanolate and agar, or mixtures of these substances.

[0234] The composition for parenteral injection may contain a physiologically acceptable sterile aqueous or non-aqueous solution, dispersion, suspension or emulsion, and a sterile powder for reconstituting into a sterile injectable solution or dispersion. Suitable aqueous and non-aqueous carriers, diluents, solvents or excipients include water, ethanol, polyols and suitable mixtures thereof.

[0235] The dosage forms of the compounds of the present invention for topical administration include ointments, powders, patches, sprays and inhalants. The active ingredient is mixed under sterile conditions with a physiologically acceptable carrier and any preservatives, buffers, or propellants that may be required if necessary.

[0236] The compounds of the present invention can be administered alone or in combination with other pharmaceutically acceptable compounds.

[0237] When using the pharmaceutical composition, a safe and effective amount of the compound of the present invention is applied to a mammal in need of treatment (such as a human), wherein the dosage during administration is a pharmaceutically effective dosage. For a person weighing 60 kg, the daily dosage is usually 1000 - 8000 mg, preferably 3000 - 6000 mg. For patients with severe infections, the daily dosage is usually 4000 - 8000 mg, administered 1 to 4 times a day. Of course, the specific dosage should also consider factors such as the route of administration and the health status of the patient, which are within the scope of the skills of a skilled physician.

[0238] The main advantages of the present invention include:

[0239] (a) The compounds of the present invention have good stability and significantly better stability than existing cefditoren under the condition of pH = 7.

[0240] (b) Reducing the risk of allergic reactions induced by the quaternary ammonium structure or impurities generated from the instability of this structure

[0241] (c) Under the condition of improving stability, the compounds of the present invention significantly improve the antibacterial activity against pathogenic bacteria such as multidrug-resistant Gram-negative bacteria Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa, which is of great significance.

[0242] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise stated, percentages and parts are weight percentages and weight parts.

[0243] Preparation Example

[0244] The structure of the compounds of the present invention was determined by nuclear magnetic resonance (NMR) or mass spectrometry (MS). NMR data was collected on a BRUKER AVANCE III 400 or BRUKER AVANCE III 500 or BRUKER AVANCE III 600 nuclear magnetic resonance spectrometer, and the solvents used for determination were deuterated dimethyl sulfoxide (DMSO-d6), deuterated chloroform (CDCl3), deuterated acetone (Acetone-d6) or deuterated methanol (CD3OD). The chemical shift was expressed in δ (ppm), and the abbreviations used to describe the peak signals were as follows: br = broad signal, s = singlet, d = doublet, dd = double doublet, t = triplet, q = quartet, m = multiplet. Mass spectrometry was determined using a Finnigan LTQ linear ion trap mass spectrometer. The silica gel used for column chromatography separation was 200 - 300 mesh, and the ratios of the eluents were all volume ratios.

[0245] The commercially available raw materials, reagents (such as acids, bases, chiral catalysts, brominating reagents, etc.), solvents (petroleum ether, ethyl acetate, methanol, dichloromethane, 1,4-dioxane, acetonitrile, etc.) used in the synthesis were directly used in the reaction without additional purification as products purchased from reagent companies.

[0246] Example 1: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((1-carboxy-2-cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 1)

[0247] Synthesis route:

[0248]

[0249] Synthesis of B3-a: Dissolve B1-a (10 g, 89.2 mmol) in THF (300 mL). Under argon protection, trimethylsilyl cyanide (12.3 mL, 98.1 mmol) was added dropwise at 0 °C, and lithium chloride (113.4 mg, 2.67 mmol) as the catalyst was added. Stir at room temperature overnight. The next day, concentrated hydrochloric acid (7.43 mL, 89.2 mmol) was added dropwise under ice bath conditions, and stirred at room temperature for 6 h. The solvent was concentrated by rotary evaporation under reduced pressure. Ethyl acetate was added, and it was washed successively with water and saturated brine, dried over anhydrous sodium sulfate, filtered, and column chromatographed with PE:EA (10:1) to obtain colorless oily B3-a (6.1 g, 48.4%). 1 H NMR (400 MHz, CDCl3) δ 4.13 (d, J = 6.3 Hz, 1H), 1.90 - 1.74 (m, 4H), 1.71 - 1.59 (m, 2H), 1.28 - 1.01 (m, 5H), 0.20 - 0.18 (m, 9H).

[0250] Synthesis of B4-a: Dissolve B3-a (6.1 g, 43.8 mmol) in absolute ethanol (100 mL). Under ice bath conditions, 10 M hydrochloric acid in ethanol solution (17.5 mL, 0.175 mol) was added dropwise. React in a sealed tube at 80 °C overnight. Monitor the reaction by TLC until completion. Concentrate the ethanol and remove part of the hydrochloric acid by rotary evaporation under reduced pressure. Ethyl acetate was added to dilute the resulting oil. The precipitated white solid particles were filtered through a sintered funnel filled with diatomaceous earth, and the filtrate was concentrated. Column chromatographed with PE:EA (10:1) to obtain colorless oily B4-a (5.0 g, 61.3%). 1 H NMR (400 MHz, DMSO-d6) δ 4.99 (s, 1H), 3.72 (d, J = 4.4 Hz, 2H), 1.70 - 1.65 (m, 3H), 1.64 - 1.48 (m, 8H).

[0251] Synthesis of B5-a: Dissolve B4-a (5.0 g, 26.9 mmol) in methanol. Under ice bath conditions, the prepared aqueous potassium hydroxide solution (4.52 g, 80.5 mmol) was added dropwise. React at room temperature overnight. Monitor the reaction by TLC until completion. Concentrate methanol under reduced pressure. Adjust the pH of the system to 2 - 3 with 6 M hydrochloric acid, extract the aqueous phase 10 times with DCM:MeOH (10:1), dry over anhydrous sodium sulfate, and dry under vacuum at 35 °C to obtain off-white solid B5-a (3.7 g, 87.1%). 1 H NMR (400 MHz, Acetone-d6) δ 5.29 (s, 1H), 4.71 (d, J = 6.8 Hz, 1H), 1.64 - 1.43 (m, 11H).

[0252] Synthesis of B6-a: Dissolve benzophenone hydrazone (9.18 g, 46.78 mmol) in petroleum ether (250 mL), add MnO2 (2.03 g, 23.39 mmol), and react at 40 °C for 45 min. Filter MnO2, and concentrate the filtrate to obtain diphenyldiazomethane. Dissolve B5-a (3.7 g, 23.39 mmol) in THF (100 mL), and slowly add the freshly prepared diphenyldiazomethane THF solution dropwise to the reaction solution, then stir at room temperature overnight. Concentrate the solvent under reduced pressure, and separate by column chromatography with PE:EA (15:1) to obtain white solid B6-a (7.2 g, 94.7%). 1 HNMR(400MHz,CDCl3)δ7.37-7.28(m,10H),6.96(s,1H),4.14(dd,J=6.2,3.2Hz,1H),2.65(d,J=6.2Hz,1H),1.78-1.71(m,1H),1.68-1.63(m,2H),1.34-1.03(m,8H).

[0253] Synthesis of B7-a: Dissolve B6-a (7.2 g, 22.19 mmol) in THF (200 mL), and successively add PPh3 (11.73 g, 44.39 mmol), N-hydroxyphthalimide (5.43 g, 33.29 mmol), and DIAD (8.63 mL, 44.39 mmol). Protect with argon and stir at room temperature for 5 h. Monitor the reaction by TLC until completion. Concentrate the solvent under reduced pressure, add methanol (200 mL), stir to form a solid, filter, and dry the filter cake to obtain off-white solid B7-a (6.4 g, 61.4%). 1 H NMR(400MHz,CDCl3)δ7.78-7.70(m,4H),7.38-7.34(m,2H),7.34-7.27(m,5H),7.22-7.19(m,3H),6.97(s,1H),2.10-2.05(m,1H),1.40-1.10(m,10H).

[0254] Synthesis of B8-a: Dissolve B7-a (6.4 g, 13.6 mmol) in MeOH (150 mL), add 85% hydrazine hydrate (1.99 mL, 54.52 mmol), and stir at room temperature for 1 h. Monitor the reaction by TLC until completion. Concentrate methanol under reduced pressure, dissolve the white solid residue in a mixed solvent of ethyl acetate and dichloromethane, filter through a sintered funnel filled with diatomaceous earth, concentrate the filtrate under reduced pressure, and separate by column chromatography to obtain colorless oil B8-a (4.3 g, 92.9%). 11H NMR (400 MHz, CDCl3) δ 7.39 - 7.31 (m, 10H), 7.00 (s, 1H), 5.61 (brs, 2H), 4.11 (d, J = 5.4 Hz, 1H), 1.81 - 1.72 (m, 1H), 1.70 - 1.63 (m, 2H), 1.63 - 1.50 (m, 3H), 1.22 - 1.04 (m, 5H).

[0255] Synthesis of B9-a: Using B8-a (4.3 g, 12.7 mmol) and N1-a (5.78 g, 13.9 mmol) as starting materials, with anhydrous methanol (350 mL) as the solvent, stirred in an ice bath for 2 h, and separated by column chromatography to obtain B9-a (5.5 g, 59.0%). 1 1H NMR (400 MHz, DMSO-d6) δ 8.84 (s, 1H), 7.37 - 7.27 (m, 20H), 7.23 - 7.20 (m, 5H), 6.85 (s, 1H), 6.80 (s, 1H), 4.50 (d, J = 6.3 Hz, 1H), 2.07 - 1.38 (m, 5H), 1.18 - 0.97 (m, 6H).

[0256] Synthesis of B10-a: Using B9-a (5.5 g, 7.75 mmol) and M1 (3.14 g, 7.75 mmol) as starting materials, dissolved in DCM (300 mL), successively added EDCI·HCl (1.78 g, 9.30 mmol) and pyridine (1.75 mL, 21.69 mmol), stirred at -15 °C for 3 h. Added ethyl acetate, washed successively with water and saturated brine, dried over anhydrous sodium sulfate, filtered, and separated by column chromatography with PE:EA (3:1) to obtain B10-a (a pair of epimers (1:1), 4.2 g, 51.7%). 1 1H NMR (400 MHz, Acetone-d6) δ 8.25 - 8.19 (m, 1H), 7.68 (d, J = 7.0 Hz, 1H), 7.48 - 7.39 (m, 13H), 7.35 - 7.30 (m, 7H), 7.30 - 7.22 (m, 7H), 6.94 - 6.91 (m, 3H), 6.77 (d, J = 2.3 Hz, 1H), 5.93 - 5.85 (m, 1H), 5.29 - 5.18 (m, 3H), 4.64 (d, J = 5.7 Hz, 1H), 4.61 - 4.55 (m, 2H), 3.79 (s, 3H), 3.75 (m, 1H), 3.56 (m, 1H), 1.80 - 1.54 (m, 3H), 1.40 - 1.22 (m, 8H).

[0257] Synthesis of B11-a: Dissolve B10-a (1 g, 0.920 mmol) in THF (30 mL), add NaI (137.9 mg, 0.920 mmol), and stir at 0 °C overnight. Under ice bath conditions, add M2 (533.9 mg, 0.920 mmol) and DIPEA (176.3 μL, 1.01 mmol). Remove the ice bath after 1 h, stir at room temperature for 1 h, and monitor the reaction completion by TLC. Add ethyl acetate, wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, and perform column chromatography with PE:EA (3:1) to obtain B11-a (a pair of epimers (1:1), 531 mg, 35.4%). 1 H NMR (400 MHz, Acetone-d6) δ 8.21 (d, J = 8.4 Hz, 1H), 7.96 (s, 1H), 7.70 (s, 1H), 7.50 - 7.39 (m, 19H), 7.37 - 7.22 (m, 27H), 7.00 (d, J = 2.3 Hz, 1 / 2H), 6.98 (d, J = 2.2 Hz, 1 / 2H), 6.95 - 6.85 (m, 4H), 6.79 (s, 1H), 6.77 (d, J = 1.5 Hz, 1H), 6.51 (s, 1H), 5.84 - 5.77 (m, 1H), 5.25 - 5.13 (m, 3H), 4.64 (d, J = 5.5 Hz, 1 / 2H), 4.56 (d, J = 6.2 Hz, 1 / 2H), 3.76 (s, 3H), 3.73 - 3.58 (m, 4H), 2.78 (s, 3H), 2.68 - 2.65 (m, 1H), 2.17 - 2.12 (m, 1H), 1.87 - 1.43 (m, 11H).

[0258] Synthesis of Compound 1: Dissolve B11-a (200 mg, 0.123 mmol) in DCM (6 mL), add triethylsilane (98.0 μL, 0.613 mmol), and cool the reaction solution to -15 °C. Dissolve TFA (0.781 μL, 12.3 mmol) in DCM (700 μL) and slowly add it dropwise to the above reaction solution. React at -15 °C for 12 h, warm to room temperature and react for 2 h, add petroleum ether and stir at room temperature for 15 min, precipitate a solid, filter, and dry the filter cake under vacuum to obtain white solid Compound 1 (a pair of epimers (4:1), 68 mg, 72.1%). 11H NMR (600 MHz, DMSO-d6) δ 10.11 (s, 1H), 9.44 (d, J = 8.0 Hz, 1H), 9.22 (s, 1H), 8.22 - 8.18 (m, 1H), 7.25 (s, 2H), 6.79 - 6.70 (m, 3H), 5.76 (dd, J = 8.0, 4.8 Hz, 1H), 5.20 (d, J = 4.9 Hz, 1 / 2H), 4.30 (d, J = 5.5 Hz, 1 / 2H), 3.75 - 3.53 (m, 5H), 3.29 - 3.23 (m, 2H), 2.69 - 2.57 (m, 2H), 1.81 - 1.58 (m, 6H), 1.22 - 1.07 (m, 5H).

[0259] Example 2: Trifluoroacetate of (6R,7R)-7-((Z)-2-(2-aminothiazol-4-yl)-2-((carboxy(tetrahydro-2H-thiopyran-4-yl))imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid compound (Compound 2)

[0260]

[0261] Synthesis of D2-a: Dissolve (methoxymethyl)triphenylphosphonium chloride (44.20 g, 128.94 mmol) in ultradry THF (200 mL). Under argon protection, dropwise add a solution of 2 M sodium bis(trimethylsilyl)amide (67.47 mL, 128.94 mmol) in THF at -10°C. React at -10°C for 2 h. Dissolve D1-a (10 g, 86.07 mmol) in ultradry THF (80 mL) and slowly add it dropwise to the above reaction solution. Stir at room temperature overnight and monitor by TLC to obtain the crude product of D2-a. 1 1H NMR (400 MHz, CDCl3) δ 5.81 (s, 1H), 3.54 (s, 3H), 2.62 - 2.56 (m, 4H), 2.54 - 2.50 (m, 2H), 2.30 - 2.25 (m, 2H).

[0262] Synthesis of D4-a: Under ice bath conditions, dropwise add 6 M HCl to the crude product of D2-a obtained in the previous step and react at room temperature for 10 h. At 0°C, dropwise add 4 M NaOH solution to the reaction solution to adjust the pH of the system to 9 - 10. Stir at room temperature for 1 h, add DCM, wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, and concentrate the organic phase under reduced pressure at 30°C. Purify by column chromatography with PE:EA (200:1) to obtain the crude product of D4-a. Without purification, directly use it in the next step. 11H NMR (400 MHz, DMSO-d6) δ 9.54 (s, 1H), 2.66 - 2.60 (m, 5H), 2.19 - 2.14 (m, 2H), 1.57 - 1.51 (m, 2H).

[0263] Synthesis of D11-a: Using D4-a as the raw material, following the synthesis method of Example 1, through six-step reactions, intermediates D6-a, D7-a, D8-a, D9-a, and D10-a were synthesized, and after purification and separation, white solid D11-a was obtained. 1 1H NMR (400 MHz, CDCl3) δ 7.36 - 7.31 (m, 10H), 6.99 (s, 1H), 4.27 (d, J = 4.3 Hz, 1H), 2.53 - 2.45 (m, 3H), 1.91 - 1.78 (m, 2H), 1.75 - 1.45 (m, 4H).

[0264] Synthesis of D12-a: Using D11-a (900 mg, 2.52 mmol) and N1-a (1.15 g, 2.77 mmol) as raw materials, the subsequent operations were the same as those for the synthesis of B9-a in Example 1, and light yellow solid D12-a (1.14 g, 60.06%) was obtained. 1 1H NMR (400 MHz, DMSO-d6) δ 8.84 (s, 1H), 7.37 - 7.25 (m, 19H), 7.24 - 7.20 (m, 6H), 6.85 (s, 1H), 6.79 (s, 1H), 4.58 - 4.52 (m, 1H), 1.98 - 1.71 (m, 4H), 1.52 - 1.32 (m, 3H), 1.32 - 1.24 (m, 2H).

[0265] Synthesis of Compound 2: Using D12-a (500 mg, 0.66 mmol) and M1 (268.78 mg, 0.66 mmol) as raw materials, following the method of Example 1, through three-step reactions, intermediates D13-a and D14-a were synthesized, and Compound 2 was obtained as a white solid (a pair of epimers (1:1), 45.2 mg). 11H NMR (600 MHz, DMSO-d6) δ 10.08 (s, 1H), 9.54 (d, J = 6.8 Hz, 1 / 2H), 9.49 (d, 1 / 2H), 9.21 (s, 1H), 8.20 (s, 1H), 7.25 (d, J = 6.4 Hz, 2H), 6.78 - 6.71 (m, 3H), 5.78 - 5.73 (m, 1 / 2H), 5.71 (m, 1 / 2H), 5.19 (d, J = 4.4 Hz, 1H), 4.35 (d, J = 5.1 Hz, 1 / 2H), 4.24 (d, J = 6.4 Hz, 1 / 2H), 3.71 - 3.61 (m, 5H), 3.36 - 3.35 (m, 2H), 2.64 - 2.61 (m, 2H), 2.05 - 1.83 (m, 5H), 1.58 - 1.42 (m, 4H).

[0266] Example 3: Trifluoroacetate salt of (6R,7R)-7-((Z)-2-(2-aminothiazol-4-yl)-2-((carboxy(tetrahydro-2H-pyran-4-yl))imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid compound (Compound 3)

[0267]

[0268] Synthesis of E2-a: Dissolve E1-a (7.00 g, 40.64 mmol) in ultradry THF (100 mL). Under argon protection at -78 °C, dropwise add a THF solution of 1 M sodium bis(trimethylsilyl)amide (45.54 mL, 45.54 mmol). Stir the reaction at -78 °C for 1 h. At the same temperature, dropwise add trimethylchlorosilane ((6.44 mL, 50.81 mmol). After 30 min, add NBS (10.85 g, 60.97 mmol) in portions, then warm the reaction to room temperature and react for 1 h. When the reaction is completed by TLC detection, quench the reaction with water under ice bath conditions. Concentrate THF under reduced pressure, wash successively with water and saturated sodium chloride solution, and extract with DCM. Combine the organic phases, dry with anhydrous sodium sulfate, and concentrate under reduced pressure. Purify by column chromatography (PE:EA = 50:1) to obtain yellow oil E2-a (8.60 g, 82.93%). 11H NMR (400 MHz, CDCl3) δ 4.23 (q, J = 7.1 Hz, 2H), 4.05 - 3.90 (m, 3H), 3.43 - 3.32 (m, 2H), 2.19 - 2.07 (m, 1H), 1.98 - 1.92 (m, 1H), 1.62 - 1.55 (m, 1H), 1.42 - 1.34 (m, 2H), 1.29 (t, J = 9.4, 4.9 Hz, 3H).

[0269] Synthesis of E3-a: E2-a (8.60 g, 34.25 mmol) was dissolved in isopropanol (60 ml). Under ice bath conditions, 10% aqueous NaOH solution (53.03 g, 132.58 mmol) was added dropwise. The reaction was heated under reflux at 85 °C for 4 h under argon protection. Using PE:EA (50:1) as the eluent, TLC was used to detect the completion of the reaction. Under ice bath conditions, the pH of the system was adjusted to 3 with 2M HCl. The mixture was extracted 10 times with a mixed solvent of DCM:MeOH (10:1) and washed with saturated sodium chloride solution. The organic phases were combined, dried over anhydrous sodium sulfate. The resulting solid was dried under vacuum at room temperature for 24 h to obtain off-white solid E3-a. It can be directly used for the next reaction without further purification. 1 1H NMR (400 MHz, DMSO-d6) δ 3.87 - 3.80 (m, 2H), 3.76 (d, J = 5.0 Hz, 1H), 3.30 - 3.18 (m, 2H), 1.85 - 1.76 (m, 1H), 1.46 - 1.33 (m, 4H).

[0270] Synthesis of Compound 3: Using E3-a (5.53 g, 34.53 mmol) as the starting material, following the method of Example 1, intermediates D4-a, D5-a, D6-a, D7-a, D8-a were synthesized. After six-step reactions, white solid Compound 3 (a pair of epimers (1:1), 39.67 mg) was prepared. 1 1H NMR (600 MHz, DMSO-d6) δ 10.14 (s, 1H), 9.53 (d, J = 6.5 Hz, 1H), 9.27 (s, 1H), 8.21 (s, 1H), 7.39 (brs, 2H), 6.79 - 6.73 (m, 2H), 6.49 (s, 1H), 5.61 - 5.59 (m, 1H), 5.28 - 5.25 (m, 1H), 5.08 (s, 1H), 4.33 (d, J = 5.7 Hz, 1H), 3.87 - 3.80 (m, 2H), 3.34 - 3.25 (m, 3H), 2.59 - 2.52 (m, 2H), 2.06 - 1.98 (m, 2H), 1.70 - 1.56 (m, 2H), 1.50 - 1.34 (m, 6H).

[0271] Example 4: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((S)-1-carboxy-2,2-dimethylpropoxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 4)

[0272] Synthetic route:

[0273]

[0274] Synthesis of C2-a: C1-a (10 g, 76.23 mmol) was added portionwise to 2 M sulfuric acid solution (80.04 mL, 160.07 mmol) at -10 °C. Aqueous sodium nitrite solution (10.52 g, 152.47 mmol) was added portionwise under the same temperature condition. The reaction system was warmed to 0 °C and reacted for 20 h. Solid sodium chloride was added to the reaction system until saturation, and then extracted with a mixed solvent of DCM:MeOH (10:1). The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and a crude product of yellow oil C2-a (7.5 g, 74.4%) was obtained. 1 HNMR(400MHz,CDCl3)δ3.94(d,J=7.7Hz,1H),2.80(d,J=7.0Hz,1H),0.95(s,9H).

[0275] Synthesis of C3-a: Benzophenone hydrazone (22.27 g, 113.50 mmol) was dissolved in petroleum ether (600 mL), and MnO2 (29.60 g, 340.50 mmol) was added. The reaction was carried out at 40 °C for 60 min. MnO2 was filtered off, and the filtrate was concentrated to obtain diphenyldiazomethane. The crude product of C2-a (7.5 g, 56.75 mmol) obtained in the previous step was dissolved in THF (150 mL), and the freshly prepared THF solution of diphenyldiazomethane was slowly added dropwise to the reaction solution, and stirred at room temperature overnight. The solvent was concentrated under reduced pressure, and separated by column chromatography with PE:EA (10:1) to obtain a white solid C3-a (2.53 g, 14.9%). 1 H NMR(400MHz,CDCl3)δ7.37-7.29(m,10H),6.98(s,1H),3.92(s,1H),0.93(s,9H).

[0276] Synthesis of C4-a: Dissolve C3-a (2.53 g, 8.48 mmol) in THF (150 mL). Under ice bath conditions, add NaOtBu (0.98 g, 10.17 mmol) portionwise, and stir the reaction for 15 min. Then, under ice bath conditions, add crushed diphenylphosphorylhydroxylamine (2.37 g, 10.17 mmol) portionwise. Stir the reaction at 0 °C for 1.5 h until completion, and quench the reaction by dropwise addition of ethanol. Add ethyl acetate, stir for 20 min, filter with a Buchner funnel, concentrate the filtrate, and perform column chromatography with PE:EA (10:1) to obtain colorless oily substance C4-a (1.13 g, 42.5%). 1 H NMR (400 MHz, CDCl3) δ 7.39 - 7.31 (m, 10H), 7.02 (s, 1H), 5.53 (brs, 2H), 3.99 (s, 1H), 0.92 (s, 9H).

[0277] Synthesis of Compound 4: Using C4-a and N1-a as starting materials, according to the method of Example 1, synthesize intermediates D5-a, D6-a, and D7-a. After four-step reactions, obtain white solid Compound 4 (169 mg). 1 H NMR (500 MHz, DMSO-d6) δ 10.01 (s, 1H), 9.52 (d, J = 7.4 Hz, 1H), 9.21 (s, 1H), 8.24 - 8.19 (m, 1H), 7.54 (brs, 2H), 6.82 - 6.80 (m, 1H), 6.73 (s, 2H), 5.77 (dd, J = 7.6, 4.8 Hz, 1H), 5.21 (d, J = 4.6 Hz, 1H), 4.19 - 4.17 (m, 1H), 3.70 (m, 3H), 3.59 (d, J = 17.5 Hz, 1H), 3.37 - 3.32 (m, 2H), 2.67 - 2.61 (m, 2H), 0.99 (s, 9H).

[0278] Example 5: Trifluoroacetate of (6R,7R)-7-((Z)-2-(2-aminothiazol-4-yl)-2-(((R)-1-carboxy-2-methylpropoxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid compound (Compound 5)

[0279] Synthetic route:

[0280]

[0281] Synthesis of C2-b: Benzophenone hydrazone (16.61 g, 84.65 mmol) was dissolved in petroleum ether (200 mL), and MnO2 (22.08 g, 253.95 mmol) was added. The reaction was carried out at 40 °C for 45 min. The MnO2 was filtered off, and the filtrate was concentrated to obtain diphenyldiazomethane. C1-b (5.00 g, 42.33 mmol) was dissolved in THF (60 mL), and the freshly prepared THF solution of diphenyldiazomethane was slowly added dropwise to the reaction solution. The remaining experimental operations were the same as those in Step 2 of Example 4. Compound C2-b (8.70 g, 72.29%) was obtained by column chromatography separation. 1 1H NMR (400 MHz, CDCl3) δ 7.36 - 7.32 (m, 10H), 6.97 (s, 1H), 4.17 (d, J = 0.8 Hz, 1H), 2.22 - 2.15 (m, 1H), 1.02 (d, J = 6.9 Hz, 3H), 0.77 (d, J = 6.9 Hz, 3H).

[0282] Synthesis of Compound 5: Using C2-b (8.99 g, 31.62 mmol) as the raw material, according to the synthesis method of Example 4, intermediates C3-b, C4-b, C5-b, and C6-b were synthesized. After five-step reactions, Compound 5 (40.74 mg) was prepared, which was a white solid. 1 1H NMR (500 MHz, MeOD) δ 7.19 (d, J = 36.4 Hz, 1H), 7.03 (s, 1H), 6.83 (d, J = 5.0 Hz, 1H), 6.72 (d, J = 5.5 Hz, 1H), 5.77 (s, 1H), 5.21 (s, 1H), 4.53 (s, 1H), 4.12 - 4.05 (m, 1H), 3.92 (d, 1H), 3.72 -

[0283] 3.66 (m, 2H), 3.62 - 3.56 (m, 1H), 3.54 - 3.47 (m, 2H), 2.78 - 2.71 (m, 2H), 2.27 - 2.18 (m, 1H), 2.01 - 1.95 (m, 1H), 1.25 - 1.19 (m, 1H), 1.05 (s, 6H), 0.89 - 0.81 (m, 2H).

[0284] Example 6: Trifluoroacetate of (6R,7R)-7-((Z)-2-(2-aminothiazol-4-yl)-2-(((R)-1-carboxy-2,2-dimethylpropoxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (Compound 6)

[0285] Synthesis route:

[0286]

[0287] Synthesis of C2-c: C1-c (10.0 g, 76.23 mmol) was added portionwise to 1 M aqueous sulfuric acid solution (114.35 mL, 114.35 mmol) under ice bath conditions. Under the same temperature conditions, sodium nitrite (31.56 g, 457.40 mmol) was dissolved in water and slowly added dropwise to the mixture. The reaction was carried out for 6 h under ice bath conditions. The next day, the product formation was detected by TLC using DCM:MeOH (15:1) as the developing solvent. Solid sodium chloride was added to the reaction system to saturate it, and then it was extracted with DCM:MeOH (10:1). The organic phases were combined, dried over anhydrous sodium sulfate, and the solvent was concentrated by rotary evaporation under reduced pressure to obtain yellow oil C2-c (3.99 g, 39.6%). 1 H NMR (400 MHz, DMSO-d6) δ 3.58 (s, 1H), 1.94 (d, J = 31.8 Hz, 1H), 0.89 (s, 9H).

[0288] Synthesis of C3-c: Benzophenone hydrazone (11.85 g, 60.38 mmol) was dissolved in petroleum ether, and MnO2 (21.00 g, 241.53 mmol) was added. The reaction was carried out at 40 °C for 45 min. The MnO2 was filtered off, and the filtrate was concentrated to obtain diphenyldiazomethane. C2-c (3.99 g, 30.19 mmol) was dissolved in THF, and the freshly prepared THF solution of diphenyldiazomethane was slowly added dropwise to the reaction solution. The mixture was stirred at room temperature overnight. The solvent was concentrated, and column chromatography was carried out using PE:EA (20:1) to obtain C3-c (4.21 g, 46.73%). 1 H NMR (400 MHz, CDCl3) δ 7.36 - 7.30 (m, 10H), 6.98 (s, 1H), 3.92 (d, J = 7.5 Hz, 1H), 2.78 (d, J = 7.5 Hz, 1H), 0.93 (s, 9H).

[0289] Synthesis of Compound 6:

[0290] Using C4-c and N1-a as raw materials, according to the synthesis method of Example 4, intermediates C5-c, C6-c, and C7-c were synthesized. After five-step reactions, bluish-gray solid Compound 6 (68.70 mg) was prepared. 11H NMR (500 MHz, DMSO-d6) δ 9.65 (d, J = 7.6 Hz, 1H), 8.23 - 8.16 (m, 1H), 7.34 - 7.07 (m, 2H), 6.83 (s, 1H), 6.73 (s, 2H), 5.73 - 5.69 (m, 1H), 5.21 (d, J = 4.6 Hz, 1H), 4.17 (s, 1H), 3.73 - 3.57 (m, 4H), 3.40 - 3.29 (m, 2H), 2.69 - 2.59 (m, 2H), 0.99 (s, 9H).

[0291] Example 7: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((1-carboxy-2,2-dimethylpropoxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 7)

[0292] Synthetic route:

[0293]

[0294] Synthesis of C1-db: Dissolve C1-da (2 g, 15.37 mmol) in DCM (20 mL). Then dissolve oxalyl chloride (1.56 mL, 18.44 mmol) in DCM (10 mL), add 2 drops of DMF, and slowly add it dropwise to the above reaction solution. Stir at room temperature for 3 h, and concentrate under reduced pressure to obtain the acyl chloride. Dissolve pyridine (2.23 mL, 27.66 mmol) and tert-butanol (1.55 mL, 16.9 mmol) in DCM (20 mL), and slowly add the freshly prepared acyl chloride dissolved in DCM (10 mL) dropwise to the reaction solution. Stir at room temperature overnight. Add ethyl acetate, and wash successively with water, dilute hydrochloric acid, and saturated brine, dry over anhydrous sodium sulfate, filter, concentrate, and perform column chromatography with PE:EA (50:1) to obtain a colorless oil C1-db (1.5 g, 52.4%). 1 1H NMR (400 MHz, CDCl3) δ 1.55 (s, 9H), 1.25 (s, 9H).

[0295] Synthesis of C3-d: Dissolve C1-db (1.3 g, 6.98 mmol) in methanol (30 mL), add sodium cyanoborohydride (351 mg, 5.58 mmol) and a small amount of bromocresol green, and add the hydrochloric acid methanol solution dropwise to maintain the reaction solution yellow. Stir at room temperature for 2 h until the reaction is complete. Add dichloromethane, and wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, concentrate, and perform column chromatography with PE:EA (20:1) to obtain C3-d (900 mg, 68.7%).1 1H NMR (400 MHz, CDCl3) δ 3.67 (d, J = 7.2 Hz, 1H), 2.87 (d, J = 7.2 Hz, 1H), 1.51 (s, 9H), 0.97 (s, 9H).

[0296] Synthesis of C4-d: Dissolve C3-d (1.3 g, 6.91 mmol) in THF (30 mL), and add diphenylphosphorylhydroxylamine (1.61 g, 6.91 mmol). Cool to 0 °C, add sodium tert-butoxide (796 mg, 8.29 mmol), and stir at 0 °C for 1.5 h until the reaction is complete. Add ethyl acetate, wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, concentrate, and perform column chromatography with PE:EA (10:1) to obtain C4-d (514 mg, 36.7%). 1 1H NMR (400 MHz, CDCl3) δ 5.55 (brs, 2H), 3.73 (s, 1H), 1.51 (s, 9H), 0.97 (s, 9H).

[0297] Synthesis of Compound 7: Using C4-d and N1-a as starting materials, according to the synthesis method of Example 4, synthesize intermediates C4-d, C5-d, C6-d, and C7-d. After four steps of reaction, white solid Compound 7 (a pair of epimers (1:1), 33 mg) is prepared. 1 1H NMR (500 MHz, DMSO-d6) δ 9.63 (d, J = 7.5 Hz, 1 / 2H), 9.53 (d, J = 7.8 Hz, 1 / 2H), 8.20 (brs, 1H), 6.85 (s, 1 / 2H), 6.79 (s, 1 / 2H), 6.74 (s, 2H), 5.77 (dd, J = 7.6, 4.8 Hz, 1 / 2H), 5.71 (dd, J = 7.3, 4.8 Hz, 1 / 2H), 5.25 - 5.19 (m, 1H), 4.21 (s, 1 / 2H), 4.15 (s, 1 / 2H), 3.74 - 3.57 (m, 4H), 3.41 - 3.30 (m, 2H), 2.73 - 2.59 (m, 2H), 1.00 (d, J = 3.4 Hz, 9H).

[0298] Example 8: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((1-carboxycyclobutoxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (Compound 8)

[0299] Synthetic route:

[0300]

[0301] Synthesis of A1-ab: Dissolve A1-aa (2 g, 9.66 mmol) in MeOH (20 mL), cool to 0 °C, and add NaOH solution (6.48 mL, 8 M). Stir at room temperature for 45 min, adjust the pH to acidic with concentrated hydrochloric acid, and concentrate the solvent under reduced pressure. Add ethyl acetate, wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, and concentrate to obtain A1-ab (1.73 g, quantitative). 1 H NMR (400 MHz, DMSO-d6) δ 2.86 - 2.78 (m, 2H), 2.58 - 2.46 (m, 2H), 2.19 - 2.09 (m, 1H), 1.85 -

[0302] 1.74 (m, 1H).

[0303] Synthesis of A1-a: Dissolve benzophenone hydrazone (3.79 g, 19.33 mmol) in petroleum ether, add MnO2 (5.04 g, 57.98 mmol), and react at 40 °C for 45 min. Filter MnO2, and concentrate the filtrate to obtain diphenyldiazomethane. Dissolve A1-ab (1.73 g, 9.66 mmol) in THF, and slowly add the freshly prepared THF solution of diphenyldiazomethane dropwise to the reaction solution. Stir at room temperature overnight. Concentrate the solvent, and separate by column chromatography with PE:EA (100:1) to obtain A1-a (1.44 g, 43.2%). 1 H NMR (400 MHz, CDCl3) δ 7.41 - 7.26 (m, 10H), 6.89 (s, 1H), 2.93 (ddd, J = 14.0, 8.7, 6.0 Hz, 2H), 2.65 (ddd, J = 13.7, 9.8, 7.0 Hz, 2H), 2.28 - 2.15 (m, 1H), 1.91 - 1.80 (m, 1H).

[0304] Synthesis of A2-a: Dissolve A1-a (1.43 g, 5.06 mmol) in DMSO (10 mL), add K2CO3 (1.68 g, 12.16 mmol) and N-hydroxyphthalimide (826 mg, 5.06 mmol), and react at 80 °C for 4 h. Add ethyl acetate,

[0305] wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, and concentrate to obtain a solid. Pulp with PE:EA (4:1), filter, collect the filter cake, and dry to obtain A2-a (925 mg, 42.8%). 11H NMR (400 MHz, CDCl3) δ 7.81 - 7.69 (m, 4H), 7.41 - 7.20 (m, 10H), 6.93 (s, 1H), 2.65 - 2.57 (m, 4H), 2.06 - 1.96 (m, 1H), 1.77 - 1.68 (m, 1H).

[0306] Synthesis of A3 - a: Dissolve A2 - a (916 mg, 2.07 mmol) in MeOH (20 mL), add hydrazine hydrate (312 μL, 8.3 mmol), and stir at room temperature for 1 h. Add ethyl acetate, wash successively with water, saturated sodium bicarbonate, and saturated brine, dry over anhydrous sodium sulfate, filter, and concentrate to obtain A3 - a (595 mg, 93.4%). 1 1H NMR (400 MHz, CDCl3) δ 7.44 - 7.25 (m, 10H), 6.96 (s, 1H), 2.57 - 2.45 (m, 2H), 2.30 - 2.18 (m, 2H), 2.05 - 1.88 (m, 2H).

[0307] Synthesis of Compound 8: Using A3 - a and N1 - a as starting materials, according to the synthesis method of Example 1, synthesize intermediates A4 - a, A5 - a, and A6 - a, and prepare Compound 8 through four - step reactions. Compound 8 is a white solid. 1 1H NMR (500 MHz, DMSO - d6) δ 9.57 (d, J = 8.4 Hz, 1H), 8.20 (t, J = 5.5 Hz, 1H), 6.83 (s, 1H), 6.74 (s, 3H), 5.82 (dd, J = 8.2, 4.7 Hz, 1H), 5.24 (d, J = 4.7 Hz, 1H), 3.78 - 3.56 (m, 4H), 3.42 - 3.29 (m, 2H), 2.72 - 2.60 (m, 2H), 2.45 -

[0308] 2.25 (m, 4H), 1.98 - 1.90 (m, 1H), 1.89 - 1.78 (m, 1H).

[0309] Example 9: (6R,7R) - 7 - ((Z) - 2 - (2 - aminothiazol - 4 - yl) - 2 - ((1 - carboxy - 2 - cyclopropoxy)imino)acetamido) - 3 - (((2 - (2 - chloro - 3,4 - dihydroxybenzamido)ethyl)thio)methyl) - 8 - oxo - 5 - thia - 1 - azabicyclo[4.2.0]oct - 2 - ene - 2 - carboxylic acid trifluoroacetate (Compound 9)

[0310] Synthetic route:

[0311]

[0312] Synthesis of B2-b: Dissolve B1-b (10 g, 0.142 mol) in THF (300 mL). Under argon protection, dropwise add trimethylsilyl cyanide (19.63 mL, 0.157 mol) at 0 °C, and add catalyst lithium chloride (181.44 mg, 4.28 mmol). Stir at room temperature overnight. The next day, under ice bath conditions, dropwise add concentrated hydrochloric acid (11.89 mL, 0.143 mol), stir at room temperature for 6 h, concentrate the solvent by rotary evaporation under reduced pressure, add ethyl acetate, wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, and perform column chromatography with PE:EA (10:1) to obtain colorless oily substance B2-b (6.1 g, 44.0%). 1 H NMR (400 MHz, CDCl3) δ 4.17 (d, J = 7.2 Hz, 1H), 3.46 (s, 1H), 1.39 - 1.30 (m, 1H), 0.74 - 0.66 (m, 2H), 0.56 - 0.49 (m, 2H).

[0313] Synthesis of B3-b: Dissolve B2-b (6.1 g, 62.8 mmol) in absolute ethanol (100 mL). Under ice bath conditions, dropwise add ethanol solution of 10 M hydrochloric acid (25.1 mL, 0.251 mol). React in a sealed tube at 80 °C overnight. Monitor the reaction by TLC until completion. Concentrate the ethanol and remove part of the hydrochloric acid by rotary evaporation under reduced pressure. Add ethyl acetate to dilute the obtained oily substance, filter the precipitated white solid particles through a sintered glass funnel filled with diatomaceous earth, and concentrate the filtrate. Perform column chromatography with PE:EA (10:1) to obtain colorless oily substance B3-b (3 g, 44.0%). 1 HNMR (600 MHz, CDCl3) δ 4.27 - 4.19 (m, 2H), 2.84 (d, 1H), 1.28 (t, J = 7.1 Hz, 3H), 1.11 - 1.04 (m, 1H), 0.54 - 0.43 (m, 4H).

[0314] Synthesis of Compound 9: Using B3-b as the raw material, according to the synthesis method of Example 1, synthesize intermediates B5-b, B6-b, B7-b, B8-b, B9-b, B10-b, B11-b. After eight-step reactions, prepare white solid Compound 9 (a pair of epimers (1:1), 50 mg). 11H NMR (600 MHz, DMSO-d6) δ 10.01 (s, 1H), 9.57 - 9.47 (m, 1H), 9.31 (s, 1H), 8.23 - 8.19 (m, 1H), 7.55 (brs, 2H), 6.80 (d, J = 14.3 Hz, 1H), 6.73 (s, 1H), 5.83 - 5.75 (m, 1H), 5.24 - 5.19 (m, 1H), 3.96 (d, J = 8.7 Hz, 1 / 2H), 3.93 (d, J = 8.5 Hz, 1 / 2H), 3.73 - 3.57 (m, 5H), 3.38 - 3.29 (m, 2H), 2.70 - 2.60 (m, 2H), 0.86 - 0.81 (m, 1H), 0.59 - 0.47 (m, 4H).

[0315] Example 10: Trifluoroacetate of (6R,7R)-7-((Z)-2-(2-aminothiazol-4-yl)-2-((carboxy(1,1-dioxotetrahydro-2H-thiopyran-4-yl))imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid compound (Compound 10)

[0316] Synthetic route:

[0317]

[0318] Synthesis of D12-b: Dissolve D12-a (800.0 mg, 1.06 mmol) in ultradry DCM (15 mL). Add mCPBA (547.43 mg, 2.70 mmol) portionwise at -10 °C. Stir the reaction at the same temperature for 2 h. Monitor the completion of the reaction by TLC using DCM:MeOH (15:1) as the eluent. Then concentrate under reduced pressure at room temperature to remove the excess solvent. Purify the mixture by column chromatography (DCM:MeOH (10:1)) to obtain yellow solid D12-b (640.20 mg, 76.74%). 1 1H NMR (400 MHz, DMSO-d6) δ 8.67 (s, 1H), 7.34 - 7.23 (m, 25H), 6.83 (s, 1H), 6.72 (s, 1H), 4.49 (d, J = 5.6 Hz, 1H), 3.18 - 3.04 (m, 4H), 1.92 - 1.69 (m, 5H).

[0319] Synthesis of Compound 10

[0320] Using D12-b (640.20 mg, 0.81 mmol) and M1 (330.14 mg, 0.81 mmol) as starting materials, according to the synthesis method of Example 1, intermediates D13-b and D14-b were synthesized. Through three-step reactions, white solid compound 10 (a pair of epimers (1:1), 43.65 mg) was prepared. 1 H NMR (600 MHz, DMSO-d6) δ 9.99 (s, 1H), 9.61 (d, J = 7.1 Hz, 1 / 2H), 9.55 (d, J = 7.5 Hz, 1 / 2H), 9.21 (s, 1H), 8.21 (s, 1H), 7.32 (brs, J = 37.1, 29.6 Hz, 2H), 6.79 (d, J = 23.9 Hz, 1H), 6.73 (s, 2H), 5.77 - 5.73 (m, 1H), 5.20 (s, 1H), 4.48 (d, J = 5.4 Hz, 1 / 2H), 4.33 (d, J = 5.4 Hz, 1 / 2H), 3.68 - 3.64 (m, 4H), 3.37 - 3.32 (m, 2H), 3.17 - 3.11 (m, 2H), 3.05 - 2.99 (m, 2H), 2.66 - 2.62 (m, 2H), 2.23 - 2.14 (m, 2H), 2.06 - 2.02 (m, 1H), 1.85 - 1.80 (m, 2H).

[0321] Example 11 (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((1-carboxy-2-(4-methyl)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 11)

[0322] Synthetic route:

[0323]

[0324] Synthesize D11-c: Using D1-c as the starting material, according to the synthesis method of Example 2, intermediates D2-c, D4-c, D6-c, D7-c, D8-c, D9-c, D10-c were synthesized. Through 8-step reactions, colorless oily substance D11-c was synthesized. 11H NMR (400 MHz, DMSO-d6) δ 7.43 - 7.39 (m, 4H), 7.38 - 7.32 (m, 4H), 7.31 - 7.26 (m, 2H), 6.88 (s, 1H), 6.20 (s, 2H), 3.96 (d, J = 5.7 Hz, 1H), 1.64 - 1.51 (m, 4H), 1.46 - 0.96 (m, 6H), 0.80 (d, J = 6.5 Hz, 3H).

[0325] Synthesis of Compound 11: Using D11-c (2.3 g, 6.51 mmol) and N1-a (2.97 g, 7.16 mmol) as starting materials, according to the synthesis method of Example 2, intermediates D12-c, D13-c, and D14-c were synthesized. Through three-step reactions, a white solid compound 11 (a pair of epimers (1:1), 767 mg) was obtained. 1 1H NMR (600 MHz, DMSO-d6) δ 10.00 (s, 1H), 9.56 - 9.45 (m, 1H), 9.21 (s, 1H), 8.21 (s, 1H), 7.47 (brs, 2H), 6.73 (s, 2H), 5.82 - 5.68 (m, 1H), 5.25 - 5.17 (m, 1H), 4.27 (dd, J = 55.1, 5.3 Hz, 1H), 3.70 - 3.57 (m, 4H), 3.38 - 3.31 (m, 2H), 2.67 - 2.60 (m, 2H), 1.98 (s, 1H), 1.80 - 1.59 (m, 6H), 1.51 - 1.39 (m, 1H), 1.34 - 1.21 (m, 3H), 0.84 (d, J = 5.2 Hz, 3H).

[0326] Example 12: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((1-carboxy-2-(4-trifluoromethyl)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 12)

[0327] Synthetic route:

[0328]

[0329] Synthesis of B1-cb: B1-ca (9.0 g, 45.88 mmol) was dissolved in ultradry DCM (300 mL). Then, dimethylhydroxylamine hydrochloride (5.59 g, 57.35 mmol), triethylamine (27.10 mL, 194.98 mmol), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (18.49 g, 96.46 mmol), and 1-hydroxybenzotriazole (9.82 g, 72.64 mmol) were added successively. The mixture was stirred at room temperature overnight, and the reaction was monitored by TLC until completion. Ethyl acetate was added, and the mixture was washed successively with water and saturated brine, and then dried over anhydrous sodium sulfate. The crude product B1-cb (9.3 g, 84.7%) was obtained. 1 H NMR (500 MHz, CDCl3) δ 3.68 (s, 3H), 3.17 (s, 3H), 2.11 - 2.02 (m, 1H), 2.02 - 1.88 (m, 5H), 1.73 - 1.67 (m, 2H), 1.60 - 1.54 (m, 2H).

[0330] Synthesis of B1-c: Using B1-cb (9.3 g, 38.87 mmol) as the raw material, it was dissolved in ultradry DCM (55 mL). A THF solution of 1 M lithium aluminum hydride (48.59 mL, 48.59 mmol) was added, and the mixture was stirred at -78 °C for 3 h. The reaction was monitored by TLC until completion. At -78 °C, a saturated solution of ammonium chloride was slowly added dropwise, and the pH of the system was adjusted to 2 - 3 with 1 M hydrochloric acid, and then stirred for 15 min. Tetrahydrofuran was added, and the mixture was washed with water, and the aqueous phase was discarded. The organic phase was added to saturated sodium carbonate solution, and the pH of the system was adjusted to 8. Then it was washed twice with saturated sodium chloride solution, dried over anhydrous sodium sulfate, and the organic phases were combined. The organic phase was filtered through a sintered funnel filled with diatomaceous earth to obtain the crude product of low-boiling B1-c, which was directly used for the next step.

[0331] Synthesis of B3-c: The crude product of B1-c obtained in the second step was added with 2 - 3 mm molecular sieves and stirred for 1 h. Under argon protection, trimethylsilyl cyanide (5.35 mL, 72.74 mmol) was added dropwise at 0 °C, and lithium chloride (49.41 mg, 1.17 mmol) as the catalyst was added. The mixture was stirred at room temperature overnight. The next day, concentrated hydrochloric acid (3.89 mL, 46.62 mmol) was added dropwise under ice bath conditions, and the mixture was stirred at room temperature for 6 h. The solvent was concentrated by rotary evaporation under reduced pressure. Ethyl acetate was added, and the mixture was washed successively with water and saturated brine, dried over anhydrous sodium sulfate, filtered, and column chromatographed with PE:EA (10:1) to obtain the yellow oil B3-c (6.9 g, 85.7%). 11H NMR (400 MHz, CDCl3) δ 4.32 (d, J = 6.0 Hz, 1H), 2.31 (d, J = 12.1 Hz, 1H), 2.02 - 2.00 (m, 1H), 1.76 - 1.71 (m, 4H), 1.28 - 1.23 (m, 5H).

[0332] Synthesis of B8 - c: Using B3 - c (6.9 g, 33.3 mmol) as the raw material, according to the synthesis method of Example 1, intermediates B4 - c, B5 - c, B6 - c, and B7 - c were synthesized. After five - step reactions and purification by column chromatography, a colorless oil B8 - c (2.4 g) was obtained. 1 1H NMR (400 MHz, CDCl3) δ 7.37 - 7.29 (m, 10H), 7.03 (s, 1H), 5.62 (s, 2H), 4.33 (d, J = 8.5 Hz, 1H), 1.98 - 1.90 (m, 1H), 1.88 - 1.77 (m, 1H), 1.72 - 1.50 (m, 5H), 1.46 - 1.34 (m, 3H).

[0333] Synthesis of Compound 12: Using B8 - c (800.0 mg, 5.86 mmol) and N1 - a (895.22 mg, 2.16 mmol) as the raw materials, according to the synthesis method of Example 1, intermediates B9 - c, B10 - c, and B11 - c were synthesized. After four - step reactions, a white solid compound 12 (a pair of epimers (1:1), 55.3 mg) was prepared. 1 1H NMR (500 MHz, DMSO - d6) δ 10.17 (s, 1H), 9.64 - 9.51 (m, 1H), 9.25 (s, 1H), 8.20 (s, 1H), 7.27 (s, 2H), 6.82 - 6.71 (m, 3H), 5.79 - 5.68 (m, 1H), 5.23 - 5.15 (m, 1H), 4.48 (d, 1H), 4.41 (d, J = 8.4 Hz, 1H), 3.72 - 3.56 (m, 4H), 3.38 - 3.32 (m, 2H), 2.69 - 2.59 (m, 2H), 2.37 - 2.26 (m, 1H), 1.93 - 1.82 (m, 1H), 1.69 - 1.47 (m, 8H).

[0334] Example 13: (6R,7R) - 7 - ((Z) - 2 - (2 - Amino - 5 - methylthiazol - 4 - yl) - 2 - ((1 - carboxy - 2 - (4,4 - difluoro) cyclohexyloxy) imino) acetamido) - 3 - (((2 - (2 - chloro - 3,4 - dihydroxybenzamido) ethyl) thio) methyl) - 8 - oxo - 5 - thia - 1 - azabicyclo[4.2.0] oct - 2 - ene - 2 - carboxylic acid trifluoroacetate (Compound 13)

[0335] Synthesis route:

[0336]

[0337] Synthesis of B1-db: Dissolve B1-da (10 g, 60.92 mmol) in ultradry DCM (300 mL). Subsequently, add hydrochloride of dimethylhydroxylamine (7.43 g, 76.15 mmol), triethylamine (35.99 mL, 258.91 mmol), 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (18.49 g, 96.46 mmol) and 1-hydroxybenzotriazole (13.03 g, 94.46 mmol). Stir at room temperature overnight and monitor the completion of the reaction by TLC. Add ethyl acetate and wash successively with water and saturated brine, then dry over anhydrous sodium sulfate. Obtain the crude product B1-db as a brownish-red oil (13 g, 103%). 1 H NMR (400 MHz, DMSO-d6) δ 3.69 (s, 3H), 3.16 (s, 3H), 2.79 - 2.66 (m, 1H), 2.23 - 2.10 (m, 2H), 1.89 - 1.80 (m, 4H), 1.80 - 1.66 (m, 2H).

[0338] Synthesis of B1-d: Using B1-db (13 g, 62.74 mmol) as the raw material, dissolve it in ultradry DCM (60 mL). Add 1M lithium aluminum hydride in THF solution (78.42 mL, 78.42 mmol) and stir at -78 °C for 3 h, monitoring the completion of the reaction by TLC. Under the condition of -78 °C, slowly drip in the saturated solution of ammonium chloride, adjust the pH of the system to 2 - 3 with 1M hydrochloric acid, and stir for 15 min. Add THF, wash with water, and discard the aqueous phase. Add the organic phase to saturated sodium carbonate solution, adjust the pH of the system to 8, wash twice with saturated sodium chloride solution, dry over anhydrous sodium sulfate, and combine the organic phases. Filter the organic phase through a sintered funnel filled with diatomaceous earth to obtain the crude product of B1-d with low boiling point, which can be directly used in the next step without further purification.

[0339] Synthesis of B3-d: Add the crude product of B1-d obtained in the second step and stir with 2 - 3 mm molecular sieve for 1 h. Under argon protection, slowly drip trimethylsilyl cyanide (8.63 mL, 68.98 mmol) at 0 °C, and add the catalyst lithium chloride (79.74 mg, 1.88 mmol). Stir at room temperature overnight. The next day, under ice bath conditions, slowly drip concentrated hydrochloric acid (6.27 mL, 75.25 mmol), stir at room temperature for 6 h, concentrate the solvent by rotary evaporation under reduced pressure, add ethyl acetate, wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, and perform column chromatography with PE:EA (10:1) to obtain the colorless oil B3-d (7.4 g, 67.4%).1 1H NMR (400 MHz, CDCl3) δ 4.12 (s, 1H), 3.51 (d, J = 6.4 Hz, 1H), 2.24 - 2.05 (m, 2H), 2.05 - 1.92 (m, 1H), 1.90 - 1.60 (m, 4H), 1.36 - 1.21 (m, 2H).

[0340] Synthesis of B8-d: Using B3-d as the raw material, following the method of Example 12, the key intermediates B4-d, B5-d, B6-d, and B7-d were synthesized. After five-step reactions and purification by column chromatography, a colorless oil B8-d (2.2 g) was obtained. 1 1H NMR (400 MHz, CDCl3) δ 7.38 - 7.27 (m, 10H), 6.99 (s, 1H), 5.67 (s, 2H), 4.17 - 4.13 (m, 1H), 2.18 - 2.06 (m, 2H), 2.04 - 1.96 (m, 2H), 1.88 - 1.84 (m, 1H), 1.83 - 1.71 (m, 4H).

[0341] Synthesis of N1-bb: Dissolve N1-ba (10.0 g, 53.70 mmol) in DCM (200 mL). Under argon protection, triethylamine (8.96 mL, 64.44 mmol) was added dropwise at 0 °C. After stirring at 0 °C for 15 min, di-tert-butyl dicarbonate (12.34 mL, 53.70 mmol) and 4-dimethylaminopyridine (1.64 g, 13.42 mmol) were added successively, and the mixture was stirred overnight at room temperature. After the reaction was completed as detected by TLC, ethyl acetate was added, and the mixture was washed successively with water and saturated brine, dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated. Column chromatography with PE:EA (3:1) gave a white solid N1-bb (12.08 g, 83.3%). 1 1H NMR (400 MHz, CDCl3) δ 8.11 (s, 1H), 3.69 (s, 3H), 3.60 (s, 2H), 2.30 (s, 3H), 1.52 (s, 9H).

[0342] Synthesis of N1-bc: Dissolve N1-bb (12.08 g, 42.19 mmol) in 1,4-dioxane. At room temperature, add selenium dioxide (9.36 g, 84.35 mmol) portionwise, and reflux the reaction mixture at 80 °C overnight. After completion of the reaction detected by TLC, cool the reaction to room temperature, adjust the pH of the system to 8 with 2 M sodium hydroxide solution, filter through a sintered funnel filled with diatomaceous earth, concentrate the filtrate, add a mixed solvent of DCM:MeOH (10:1), wash with saturated brine, combine the organic phases, dry over anhydrous sodium sulfate, filter, concentrate the filtrate, and perform column chromatography with PE:EA (15:1) to obtain a pinkish-white solid N1-bc (1.74 g, 13.7%). 1 1H NMR (400 MHz, CDCl3) δ 8.02 (s, 1H), 3.92 (s, 3H), 2.72 (s, 3H), 1.52 (s, 9H).

[0343] Synthesis of N1-b: Dissolve N1-bc (1.74 g, 5.79 mmol) in methanol (30 mL). Under ice bath conditions, slowly dropwise add the prepared potassium carbonate solution (880.78 mg, 6.37 mmol). After completion of the reaction detected by TLC, remove the solvent methanol by concentration under reduced pressure, adjust the pH of the system to 2 - 3 with 2 M hydrochloric acid, and white solid precipitates in the system. Filter the mixture through a sintered funnel, and then wash the filter cake with petroleum ether. Dry the filter cake under vacuum at 35 °C. Obtain a crude white solid N1-b (1.9 g, 114.6%) containing a little inorganic salt. 1 1H NMR (600 MHz, DMSO-d6) δ 11.70 (s, 1H), 2.62 (s, 3H), 1.46 (s, 9H).

[0344] Synthesis of compound 13: Using B8-d (2.2 g,, 5.86 mmol) and N1-b (2.67 g, 6.45 mmol) as raw materials, according to the method of Example 12, synthesize intermediates B9-d, B10-d, B11-d, to obtain a white solid compound 13 (a pair of epimers (1:1), 97 mg). 11H NMR (600 MHz, DMSO-d6) δ 11.60 (s, 1H), 10.02 (s, 1H), 9.57 - 9.47 (m, 1H), 9.21 (s, 1H), 8.21 (s, 1H), 6.73 (s, 2H), 5.82 - 5.75 (m, 1H), 5.20 - 5.15 (m, 1H), 4.43 (d, J = 6.0 Hz, 1 / 2H), 4.31 (d, J = 7.0 Hz, 1 / 2H), 3.75 - 3.61 (m, 4H), 3.41 - 3.35 (m, 4H), 2.69 - 2.60 (m, 2H), 2.39 (d, J = 4.4 Hz, 3H), 2.06 - 1.92 (m, 5H), 1.88 - 1.70 (m, 4H), 1.45 (s, 3H).

[0345] Example 14: (6R,7R)-7-((Z)-2-(2-Amino-5-chlorothiazol-4-yl)-2-((1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 14)

[0346] Synthetic route:

[0347]

[0348] Synthesis of B9-e: Using B8-d (2.4 g, 6.39 mmol) and N1-c (3.16 g, 7.03 mmol) as starting materials, stir in an ice bath in anhydrous methanol (150 mL) for 2 h, and separate by column chromatography to obtain B9-e (4.6 g, 89.24%). 1 1H NMR (400 MHz, DMSO-d6) δ 9.00 (s, 1H), 7.32 - 7.26 (m, 17H), 7.26 - 7.18 (m, 8H), 6.85 (s, 1H), 4.65 (d, J = 6.1 Hz, 1H), 2.11 - 1.89 (m, 4H), 1.90 - 1.47 (m, 1H), 1.50 - 1.24 (m, 4H).

[0349] Synthesis of Compound 14: Using B9-e (4.6 g, 5.70 mmol) and M1 (2.31 g, 5.70 mmol) as starting materials, according to the method of Example 1, synthesize intermediates B9-e and B10-e, and obtain the white solid Compound 14 (a pair of epimers (1:1), 500 mg) through three steps. 11H NMR (500 MHz, DMSO-d6) δ 10.00 (s, 1H), 9.54 (d, J = 8.2 Hz, 1 / 2H), 9.48 (d, J = 8.3 Hz, 1 / 2H), 9.21 (s, 1H), 8.20 (s, 1H), 7.30 (brs, 2H), 6.74 (s, 2H), 5.83 - 5.72 (m, 1H), 5.23 - 5.14 (m, 1H), 4.42 (d, J = 5.9 Hz, 1 / 2H), 4.30 (d, J = 6.9 Hz, 1 / 2H), 3.77 - 3.53 (m, 4H), 3.43 - 3.27 (m, 2H), 2.73 - 2.58 (m, 2H), 2.06 - 1.89 (m, 4H), 1.88 - 1.68 (m, 3H), 1.48 - 1.32 (m, 2H).

[0350] Example 15: (6R,7R)-7-((Z)-2-(2-Amino-5-bromothiazol-4-yl)-2-((1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 15)

[0351] Synthetic route:

[0352]

[0353] Synthesis of B9-f: Using B8-d (1.2 g, 3.20 mmol) and N1-d (1.73 g, 3.52 mmol) as starting materials, stir in an ice bath in anhydrous methanol (80 mL) for 2 h, and separate by column chromatography to obtain B9-f (2.0 g, 73.5%). 1 1H NMR (400 MHz, DMSO-d6) δ 8.76 (s, 1H), 7.39 - 7.16 (m, 25H), 6.83 (s, 1H), 4.36 (d, 1H), 1.99 - 1.88 (m, 4H), 1.85 - 1.45 (m, 5H).

[0354] Synthesis of Compound 15: Using B9-f (2.0 g, 2.35 mmol) and M1 (952.75 mg, 2.35 mmol) as starting materials, according to the method of Example 1, synthesize intermediates B10-f and B11-f, and obtain the white solid Compound 15 (a pair of epimers (1:1), 260 mg) through three steps. 11H NMR (500 MHz, DMSO-d6) δ 10.00 (s, 1H), 9.51 (d, J = 8.1 Hz, 1 / 2H), 9.47 (d, J = 8.4 Hz, 1 / 2H), 9.22 (s, 1H), 8.21 (s, 1H), 7.43 (s, 2H), 6.73 (s, 2H), 5.83 - 5.73 (m, 1H), 5.22 - 5.16 (m, 1H), 4.43 (d, J = 5.5 Hz, 1 / 2H), 4.31 (d, J = 6.2 Hz, 1 / 2H), 3.70 - 3.60 (m, 4H), 3.39 -

[0355] 3.31 (m, 2H), 2.70 - 2.58 (m, 2H), 2.02 - 1.94 (m, 4H), 1.82 - 1.71 (m, 3H), 1.41 - 1.34 (m, 2H).

[0356] Example 16: Trifluoroacetate of (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((1-carboxy-2-cyclohexyloxy)imino)acetamido)-3-(((2-(2-bromo-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid compound (Compound 16)

[0357]

[0358] Synthesis of Compound 16: Using B8-a (4.3 g, 12.7 mmol) and N1-d (5.78 g, 13.9 mmol) as raw materials, the subsequent operations were the same as in Example 15. After four-step reactions of synthesizing intermediates B9-g, B10-g, and B11-g, white solid Compound 16 (a pair of epimers (4:1), 68 mg) was obtained. 1 1H NMR (500 MHz, DMSO-d6) δ 10.11 (s, 1H), 9.51 (d, J = 7.8 Hz, 1 / 4H), 9.44 (d, J = 8.0 Hz, 3 / 4H), 9.22 (s, 1H), 8.22 - 8.18 (m, 1H), 7.25 (s, 2H), 6.79 - 6.70 (m, 3H), 5.76 (m, 3 / 4H), 5.73 - 5.69 (m, 1 / 4H), 5.20 (d, J = 4.9 Hz, 1H), 4.30 (d, J = 5.5 Hz, 3 / 4H), 4.22 (d, J = 6.2 Hz, 1 / 4H), 3.75 - 3.53 (m, 5H), 3.29 - 3.23 (m, 2H), 2.69 - 2.57 (m, 2H), 1.81 - 1.58 (m, 6H), 1.22 - 1.07 (m, 5H).

[0359] Example 17: Trifluoroacetate of (6R,7R)-7-((Z)-2-(2-aminothiazol-4-yl)-2-(((S)-1-carboxy-2-methylpropoxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid compound (Compound 17)

[0360]

[0361] Synthesis of C1-e: Dissolve benzophenone hydrazone (16.61 g, 84.65 mmol) in petroleum ether (200 mL), add MnO2 (22.08 g, 253.95 mmol), and react at 40 °C for 45 min. Filter MnO2, and concentrate the filtrate to obtain diphenyldiazomethane. Dissolve C1-ea (5.00 g, 42.33 mmol) in THF (60 mL), and slowly add the freshly prepared diphenyldiazomethane THF solution dropwise to the reaction solution. The remaining experimental operations are the same as in Step 6 of Example 13, and C1-e (8.99 g, 74.70%) is obtained by column chromatography separation. 1 H NMR (400 MHz, CDCl3) δ 7.36 - 7.30 (m, 10H), 6.96 (s, 1H), 4.16 (dd, J = 6.1, 3.2 Hz, 1H), 2.67 (d, J = 6.1 Hz, 1H), 1.02 (d, J = 6.9 Hz, 3H), 0.76 (d, J = 6.9 Hz, 3H).

[0362] Synthesis of C2-e: Using C1-e (8.99 g, 31.62 mmol) as the raw material and ultra-dry THF as the solvent, under ice bath conditions, add sodium hydride (1.52 g, 37.94 mmol) protected by mineral oil in batches, and stir the reaction for 15 min. Then, under ice bath conditions, add crushed diphenylphosphorylhydroxylamine (8.85 g, 37.94 mmol) in batches. The subsequent experimental operations are the same as in the synthesis of C4-d in Example 7, and a colorless oil C2-e (4.20 g, 44.38%) is obtained by column chromatography. 1 H NMR (400 MHz, DMSO-d6) δ 7.41 - 7.29 (m, 11H), 6.88 (s, 1H), 6.22 (s, 2H), 3.94 (d, J = 5.8 Hz, 1H), 0.81 (d, J = 6.9 Hz, 6H).

[0363] Synthesis of Compound 17: Using C2-e (2.50 g, 8.35 mmol) and N1-a (3.81 g, 9.19 mmol) as raw materials, according to the synthesis method of Example 6, intermediates C3-e, C4-e, and C5-e were synthesized. After four-step reactions, compound 17 (40.74 mg) was prepared, which is a white solid. 1 H NMR (500 MHz, DMSO-d6) δ 10.01 (s, 1H), 9.49 (d, J = 8.0 Hz, 1H), 9.22 (s, 1H), 8.21 (s, 1H), 7.50 (brs, 2H), 6.81 (s, 1H), 6.73 (s, 2H), 5.81 - 5.77 (m, 1H), 5.21 (d, J = 4.6 Hz, 1H), 4.32 (d, J = 5.3 Hz, 1H), 3.69 - 3.60 (m, 4H), 3.38 - 3.32 (m, 2H), 2.64 (m, 2H), 2.18 - 2.05 (m, 2H), 2.15 - 2.10 (m, 1H), 0.97 - 0.94 (m, 6H).

[0364] Example 18: (6R,7R)-7-((Z)-2-(2-Amino-5-chlorothiazol-4-yl)-2-((1-carboxy-(R)-3,3,3-trifluoropropoxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 18)

[0365] Synthesis route:

[0366]

[0367] Synthesis of C1-f: Dissolve C1-fa (10 g, 0.063 mol) in ultra-dry DMF (300 mL). Under ice-bath conditions, add cesium carbonate (21.64 g, 0.066 mol) batch by batch, and then add p-methoxybenzyl chloride (14.86 g, 0.094 mol) drop by drop. Heat under reflux at 80 °C for 2 h. Monitor the reaction by TLC until it is complete. Cool the reaction to room temperature, and under ice-bath conditions, add saturated ammonium chloride solution to quench the reaction. Adjust the pH of the system to 7 with 1 M HCl solution. Add ethyl acetate, wash successively with water and saturated brine, dry over anhydrous sodium sulfate, filter, and perform column chromatography with PE:EA (20:1) to obtain a colorless oil, C1-f (16 g, 91%). 11H NMR (500 MHz, CDCl3) δ 7.31 - 7.28 (m, 2H), 6.92 - 6.89 (m, 2H), 5.24 (d, J = 1.5 Hz, 2H), 3.91 (s, 1H), 3.81 (s, 3H), 1.57 (s, 3H).

[0368] Synthesis of C2-f: C1-f (12 g, 0.043 mol) was dissolved in THF (350 mL). Under ice-bath conditions, 60% sodium hydride protected with mineral oil (2.07 g, 0.052 mol) was added portionwise, and the reaction was stirred for 15 min. Then, under ice-bath conditions, crushed diphenylphosphorylhydroxylamine (12.07 g, 0.052 mmol) was added in batches. The reaction was stirred at 0 °C for 1.5 h until complete, and the reaction was quenched by dropwise addition of ethanol. Ethyl acetate was added, and the mixture was stirred for 20 min, filtered through a Buchner funnel, the filtrate was concentrated, and column chromatography with PE:EA (10:1) gave yellow oil C2-f (5.6 g, 33.2%). 1 1H NMR (500 MHz, CDCl3) δ 7.33 - 7.29 (m, 2H), 6.91 - 6.88 (m, 2H), 5.64 (s, 2H), 5.22 (s, 2H), 3.81 (s, 3H), 1.58 (s, 3H).

[0369] Synthesis of Compound 18: Using C2-f and N1-c as raw materials, according to the synthesis method of Example 17, intermediates C3-f, C4-f, and C5-f were synthesized, and after four-step reactions, Compound 18 was prepared, which is a white solid. 1 1H NMR (500 MHz, DMSO-d6) δ 10.03 (s, 1H), 9.80 (s, 1H), 9.22 (s, 1H), 8.28 - 8.16 (m, 1H), 7.44 (s, 2H), 6.74 (s, 2H), 5.79 - 5.70 (m, 1H), 5.18 (s, 1H), 3.71 - 3.58 (m, 3H), 3.36 - 3.30 (m, 2H), 2.72 - 2.59 (m, 2H), 1.99 (s, 1H), 1.67 (s, 3H).

[0370] Example 19: (6R,7R)-7-((Z)-2-(2-Amino-5-chlorothiazol-4-yl)-2-((1-carboxy-2-cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 19)

[0371] Synthetic route:

[0372]

[0373] Synthesis of B9-h: Using B8-a (2.5 g, 7.37 mmol) and N1-c (3.64 g, 8.10 mmol) as raw materials, stir in an ice bath in anhydrous methanol (300 mL) for 2 h, and obtain B9-h (1.8 g, 31.7%) by column chromatography separation. 1 H NMR (400 MHz, DMSO-d6) δ 8.84 (s, 1H), 7.35 - 7.27 (m, 25H), 6.84 (s, 1H), 4.38 (d, J = 9.2 Hz, 1H), 1.98 - 1.93 (m, 1H), 1.85 - 1.26 (m, 10H).

[0374] Synthesis of Compound 19: Using B9-h (1.8 g, 2.34 mmol) and M1 (947.01 mg, 2.34 mmol) as raw materials, according to the synthesis method of Example 16, through three-step reactions, obtain white solid Compound 19 (a pair of epimers (1:1), 60 mg). 1 HNMR (500 MHz, DMSO-d6) δ 10.01 (s, 1H), 9.51 (d, J = 8.2 Hz, 1 / 2H), 9.47 (d, J = 8.4 Hz, 1 / 2H), 9.22 (s, 1H), 8.22 (s, 1H), 7.41 (brs, 2H), 6.74 (s, 2H), 5.82 - 5.75 (m, 1H), 5.24 - 5.17 (m, 1H), 4.33 (d, J = 5.3 Hz, 1 / 2H), 4.26 (d, J = 5.9 Hz, 1 / 2H), 3.71 - 3.58 (m, 4H), 3.39 - 3.31 (m, 2H), 2.69 - 2.60 (m, 2H), 1.84 - 1.77 (m, 2H), 1.71 - 1.60 (m, 4H), 1.20 - 1.15 (m, 5H).

[0375] Example 20: Trifluoroacetate of (6R,7R)-7-((Z)-2-(2-aminothiazol-4-yl)-2-((carboxy(4-tert-butylcyclohexyl))imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid compound (Compound 20)

[0376]

[0377] Synthesis of D11-d: Using D1-d (10 g, 64.876 mmol) as the raw material, the synthesis method was the same as that in Example 11 to synthesize intermediates D2-d, D4-d, D6-d, D7-d, D8-d, D9-d, and D10-d. After eight-step reactions and purification by column chromatography, white solid D11-d (1.0 g) was obtained. 1 H NMR (400 MHz, CDCl3) δ 7.36 - 7.30 (m, 10H), 6.99 (s, 1H), 4.16 (d, J = 5.2 Hz, 1H), 1.74 - 1.68 (m, 3H), 1.64 - 1.58 (m, 2H), 1.18 - 1.03 (m, 3H), 0.93 - 0.86 (m, 2H), 0.80 (s, 9H).

[0378] Synthesis of Compound 20: Using D11-d (1.0 g, 2.53 mmol) and N1-a (1.15 g, 2.78 mmol) as the raw materials, the subsequent operations were the same as those in Example 11 to synthesize intermediates D12-d, D13-d, and D14-d. After four steps, Compound 20 (a pair of epimers (2:3), 53.4 mg) was obtained. 1 H NMR (600 MHz, DMSO-d6) δ 10.05 (s, 1H), 9.56 (d, J = 7.6 Hz, 2 / 5H), 9.51 (d, J = 7.9 Hz, 3 / 5H), 9.24 (s, 1H), 8.23 - 8.21 (m, 1H), 7.40 (brs, J = 57.5 Hz, 2H), 6.78 (s, 1H), 6.76 - 6.71 (m, 3H), 5.80 - 5.75 (m, 3 / 5H), 5.73 - 5.69 (m, 2 / 5H), 5.24 - 5.19 (m, 1H), 4.32 (d, J = 5.0 Hz, 3 / 5H), 4.21 (d, J = 6.1 Hz, 2 / 5H), 3.74 - 3.67 (m, 4H), 3.36 - 3.31 (m, 2H), 2.68 - 2.58 (m, 2H), 1.90 - 1.81 (m, 1H), 1.78 - 1.69 (m, 5H), 1.24 - 1.15 (m, 2H), 0.98 - 0.93 (m, 2H), 0.82 (s, 9H).

[0379] Example 21: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 21)

[0380] Synthesis route:

[0381]

[0382] Synthesis of B9-i: Using B8-d (2.2 g, 5.86 mmol) and N1-a (2.67 g, 6.45 mmol) as raw materials, stir in an ice bath in anhydrous methanol (150 mL) for 2 h, and obtain B9-i (3.7 g, 81.8%) by column chromatography separation. 1 H NMR (500 MHz, DMSO-d6) δ 8.62 (s, 1H), 7.30 (m, 20H), 7.21 (s, 5H), 6.81 (s, 1H), 6.65 (s, 1H), 4.43 (d, J = 3.5 MHz, 1H), 1.99 - 1.90 (m, 4H), 1.82 - 1.79 (m, 1H), 1.79 - 1.76 (m, 1H), 1.76 - 1.73 (m, 1H), 1.73 - 1.66 (m, 2H).

[0383] Synthesis of compound 21: Using B9-i (3.7 g, 4.97 mmol) and M1 (1.94 g, 4.79 mmol) as raw materials, according to the steps of Example 15, synthesize intermediates B10-i and B11-i. After three-step reactions, obtain compound 21 (a pair of epimers (1:1), 850 mg), which is a white solid. 1 H NMR (600 MHz, DMSO-d6) δ 9.62 (d, J = 7.7 Hz, 1 / 2H), 9.55 (d, J = 8.0 Hz, 1 / 2H), 8.21 (s, 1H), 6.87 (s, 1 / 2H), 6.82 (s, 1 / 2H), 6.75 (s, 2H), 5.77 (m, 1 / 2H), 5.72 (m, 1 / 2H), 5.24 - 5.20 (m, 1H), 4.45 (d, J = 5.8 Hz, 1 / 2H), 4.32 (d, J = 6.9 Hz, 1 / 2H), 3.75 - 3.57 (m, 4H), 3.43 - 3.29 (m, 2H), 2.73 - 2.59 (m, 2H), 2.09 - 1.67 (m, 9H).

[0384] Example 22: (6R,7R)-7-((Z)-2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-((1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 22)

[0385] Synthesis route:

[0386]

[0387] Synthesis of N1-eb: Dissolve N1-ea (15.5 g, 134.76 mmol) in DCM (200 mL). Under argon protection, add triethylamine (26.2 mL, 188.66 mmol) dropwise at 0 °C. After stirring at 0 °C for 15 min, add di-tert-butyl dicarbonate (37.15 mL, 161.71 mmol) and 4-dimethylaminopyridine (4.1 g, 36.69 mmol) in sequence, and stir at room temperature overnight. After detecting the completion of the reaction by TLC, add DCM, wash with water and saturated brine in sequence, dry over anhydrous sodium sulfate, filter, and concentrate the filtrate. Column chromatography with PE:EA (5:1) gives white solid N1-eb (15.4 g, 53.1%). 1 H NMR (400 MHz, DMSO-d6) δ 12.19 (s, 1H), 2.38 (s, 3H), 1.49 (s, 9H).

[0388] Synthesis of N1-ec: In a dry 1 L three-necked flask, dissolve diisopropylamine (25.28 mL, 180.4 mmol) in THF (150 mL). Under argon protection, add 2.5 M n-butyllithium in THF solution (81.9 mL, 204.75 mmol) dropwise at -78 °C. React at -78 °C for 30 min. Then, at the same temperature, add a THF solution of N1-eb (9.70 g, 45.1 mmol) dropwise. After reacting for 30 min, still at -78 °C, add dry ice (200.0 g, 4.54 mol). After detecting the completion of the reaction by TLC, add saturated ammonium chloride solution to quench the reaction under ice bath conditions. Concentrate the solvent THF by rotary evaporation under reduced pressure. Add ethyl acetate and water, and adjust the pH of the system to 8.5 with 2 M hydrochloric acid. Discard the ethyl acetate layer. Adjust the pH of the aqueous phase to 2 with 2 M hydrochloric acid, wash with ethyl acetate and saturated brine, combine the organic phases, dry over anhydrous sodium sulfate, filter, concentrate the filtrate, and column chromatography with PE:EA (3:1) gives light yellow solid N1-ec (6.8 g, 58.2%). 1 H NMR (400 MHz, DMSO-d6) δ 12.33 (s, 1H), 3.73 (s, 2H), 1.50 (s, 9H).

[0389] Synthesis of N1-e: Dissolve N1-ec (3.6 g, 13.9 mmol) in 1,4-dioxane. At room temperature, add selenium dioxide (3.0 g, 27.8 mmol) portionwise, and reflux the reaction mixture at 85 °C for 3 h. After completion of the reaction detected by TLC, cool the reaction to room temperature, filter through a fritted funnel packed with diatomaceous earth, concentrate the filtrate, add ethyl acetate and water, and adjust the pH of the system to 9 - 10 with 2 M sodium hydroxide solution. Discard the ethyl acetate layer. Adjust the aqueous phase to pH 2 with 2 M hydrochloric acid, wash with ethyl acetate and saturated brine, combine the organic phases, dry over anhydrous sodium sulfate, filter, and concentrate the filtrate to obtain a yellow foamy solid N1-e (2.2 g, 58.0%). 1 1H NMR (600 MHz, DMSO-d6) δ 12.78 (s, 1H), 1.50 (s, 9H).

[0390] Synthesis of Compound 22: Using B8-d (0.57 g, 1.76 mmol) and N1-e (0.60 g, 1.60 mmol) as starting materials, according to the synthesis method of Example 21, synthesize intermediates B9-j, B10-j, B11-j, and after four steps, prepare Compound 22 (a pair of epimers (1:1), 73 mg), which is a white solid. 1 1H NMR (500 MHz, DMSO-d6) δ 10.02 (s, 1H), 9.64 - 9.55 (m, 1H), 9.23 (s, 1H), 8.22 (d, 1H), 8.18 (s, 2H), 6.74 (s, 2H), 5.81 - 5.76 (m, 1H), 5.21 - 5.17 (m, 1H), 4.46 (d, J = 4.8 Hz, 1H), 4.34 (d, J = 6.4 Hz, 1H), 3.71 - 3.59 (m, 4H), 3.37 - 3.32 (m, 2H), 2.68 - 2.60 (m, 2H), 2.06 - 1.94 (m, 4H), 1.83 - 1.70 (m, 3H), 1.46 - 1.36 (m, 2H).

[0391] Example 27: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((S)-1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 23)

[0392] Synthetic route:

[0393]

[0394] Synthesis of F1-a and F2-a: Dissolve B8-d (13.8 g, 38.29 mmol) in anhydrous diethyl ether (500 mL). At 0 °C, successively add chiral catalyst (2R)-2,3-dihydro-2-phenylimidazo[2,1-b]benzothiazole (1.45 g, 5.74 mmol), N,N-diisopropylethylamine (6.67 mL, 38.29 mmol), and diphenylacetic anhydride (4.67 g, 11.49 mmol). React overnight under this temperature condition. The first chiral resolution gives off-white solid F1-a (racemate 10.0 g, recovery rate 72.5%) and F2-a (2.3 g, yield 36%, ee value 98%). Carry out the same experimental operation on the recovered racemate F1-a (10 g, 27.75 mmol). At 0 °C, successively add chiral catalyst (2R)-2,3-dihydro-2-phenylimidazo[2,1-b]benzothiazole (0.70 g, 2.77 mmol), N,N-diisopropylethylamine (4.83 mL, 27.75 mmol), and diphenylacetic anhydride (5.64 g, 13.87 mmol). React overnight under this temperature condition. The second chiral resolution gives off-white solid F1-a (racemate 8 g, recovery rate 80%, ee value 74%) and colorless oil F2-a (6.4 g, yield 56%, ee value 98%). Carry out the same experimental operation on the recovered racemate F1-a (8.0 g, 22.20 mmol). At 0 °C, successively add chiral catalyst (2R)-2,3-dihydro-2-phenylimidazo[2,1-b]benzothiazole (0.56 g, 2.22 mmol), N,N-diisopropylethylamine (3.87 mL, 22.20 mmol), and diphenylacetic anhydride (4.51 g, 11.10 mmol). React overnight under this temperature condition. The third chiral resolution gives colorless oil F1-a (7.3 g, recovery rate 91.3%, ee value 98%) and racemate F2-a (1.74 g, yield 14.1%, ee value 60%). F1-a: 1 1H NMR (400 MHz, CDCl3) δ 7.37 - 7.31 (m, 10H), 6.98 (s, 1H), 4.24 - 4.19 (m, 1H), 2.76 (d, J = 5.4 Hz, 1H), 2.17 - 2.08 (m, 1H), 2.04 - 2.00 (m, 1H), 1.90 - 1.80 (m, 1H), 1.79 - 1.70 (m, 2H), 1.69 - 1.61 (m, 2H), 1.58 - 1.50 (m, 2H). F2-a: 11H NMR (600 MHz, CDCl3) δ 7.38 - 7.27 (m, 20H), 6.96 (s, 1H), 5.15 (s, 1H), 5.11 (d, J = 4.5 Hz, 1H), 1.99 - 1.98 (m, 1H), 1.60 - 1.46 (m, 4H), 1.45 - 1.38 (m, 2H), 1.33 - 1.23 (m, 2H).

[0395] Synthesis of F11-a: Dissolve F1-a (4.0 g, 11.10 mmol) in anhydrous diethyl ether (150 mL), and successively add PPh3 (5.82 g, 22.20 mmol), N-hydroxyphthalimide (2.72 g, 16.65 mmol) and DIAD (4.37 mL, 22.20 mmol). Under argon protection, stir at room temperature for 5 h. Monitor the reaction by TLC until completion. Concentrate the solvent under reduced pressure, add methanol (200 mL), stir to form a solid, filter, and dry the filter cake to obtain white solid F11-a (3.2 g, 57.03%, ee value is 99%). 1 1H NMR (400 MHz, CDCl3) δ 7.74 (m, 4H), 7.35 - 7.27 (m, 7H), 7.23 - 7.18 (m, 3H), 6.97 - 6.95 (m, 1H), 4.67 (d, J = 7.5 Hz, 1H), 2.18 - 2.09 (m, 3H), 2.07 - 1.96 (m, 2H), 1.75 - 1.60 (m, 4H).

[0396] Synthesis of Compound 23: Using F11-a (3.2 g, 6.33 mmol) as the raw material, according to the synthesis method of Example 21, synthesize intermediates F12-a, F13-a, F14-a, F15-a. After five-step reactions, obtain Compound 23 as a white solid (236 mg). 1 1H NMR (500 MHz, DMSO-d6) δ 10.01 (s, 1H), 9.60 (s, 1H), 9.21 (s, 1H), 8.21 (s, 1H), 7.45 (s, 2H), 6.79 - 6.69 (m, 3H), 5.72 (s, 1H), 5.24 - 5.17 (m, 1H), 4.27 (d, J = 6.0 Hz, 1H), 3.69 - 3.63 (m, 4H), 3.36 - 3.31 (m, 2H), 2.66 - 2.61 (m, 2H), 1.95 - 1.74 (m, 7H), 1.43 - 1.37 (m, 2H).

[0397] Example 24: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((R)-1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid trifluoroacetate (Compound 24)

[0398] Synthetic route:

[0399]

[0400] Synthesis of F3-a: Dissolve F2-a (10 g, 18.03 mmol) in THF (200 mL). Under ice bath condition, dropwise add an aqueous solution of potassium hydroxide (3.03 g, 54.09 mmol). React at room temperature for 12 h. Monitor the reaction by TLC until completion. Concentrate the solvent under reduced pressure. Adjust the pH of the system to 8 - 9 with 2M sodium hydroxide solution. Add ethyl acetate and water for extraction. Discard the organic phase and retain the aqueous phase. Adjust the pH of the aqueous phase to 2 - 3 with 2M hydrochloric acid. Extract with a mixed solvent of DCM:MeOH (10:1) and saturated aqueous sodium chloride solution. Combine the organic phases, dry with anhydrous sodium sulfate, filter, and concentrate the organic phase to obtain a slightly off-white solid F3-a containing a small amount of inorganic salts (3.5 g, 100.0%).

[0401] Synthesis of F4-a: Dissolve benzophenone hydrazone (7.07 g, 36.05 mmol) in petroleum ether (200 mL). Add MnO2 (9.40 g, 108.15 mmol) and react at 40 °C for 60 min. Filter MnO2 and concentrate the filtrate to obtain diphenyldiazomethane. Dissolve the crude product of F3-a obtained in the previous step (3.5 g, 18.02 mmol) in THF (80 mL). Slowly add the freshly prepared THF solution of diphenyldiazomethane to the reaction solution and stir at room temperature overnight. Concentrate the solvent under reduced pressure. Separate by column chromatography with PE:EA (10:1) to obtain a yellow transparent oil F4-a (5.3 g, ee value is 94%, 81.6%). 1 H NMR (500 MHz, CDCl3) δ 7.38 - 7.30 (m, 11H), 6.98 (s, 1H), 4.21 (dd, J = 5.7, 3.5 Hz, 1H), 2.74 (d, J = 5.7 Hz, 1H), 2.16 - 2.07 (m, 1H), 2.05 - 1.98 (m, 2H), 1.90 - 1.82 (m, 1H), 1.78 - 1.69 (m, 2H), 1.68 - 1.57 (m, 3H).

[0402] Synthesis of F5-a: Dissolve F4-a (5.3 g, 14.71 mmol) in anhydrous diethyl ether (120 mL), and successively add PPh3 (7.71 g, 29.41 mmol), N-hydroxyphthalimide (3.60 g, 22.06 mmol) and DIAD (5.79 mL, 29.41 mmol). Under argon protection, stir at room temperature for 5 h. Monitor the reaction by TLC until completion. Concentrate the solvent under reduced pressure, add methanol (100 mL), stir to form a solid, filter, and dry the filter cake to obtain white solid F5-a (3.5 g, ee value 99%, 62.4%). 1 1H NMR (400 MHz, CDCl3) δ 7.78 - 7.71 (m, 4H), 7.36 - 7.27 (m, 8H), 7.23 - 7.18 (m, 3H), 6.96 (s, 1H), 4.67 (d, J = 7.5 Hz, 1H), 2.15 - 2.10 (m, 2H), 2.07 - 1.97 (m, 2H), 1.76 - 1.60 (m, 4H), 1.51 - 1.38 (m, 1H).

[0403] Synthesis of Compound 24: Using F5-a (3.5 g, 6.92 mmol) as the raw material, according to the method of Example 23, synthesize intermediates F6-a, F7-a, F8-a, F9-a. After five-step reactions, obtain Compound 24 as a white solid (197 mg). 1 1H NMR (500 MHz, DMSO-d6) δ 10.03 (s, 1H), 9.51 (d, J = 12.7 Hz, 1H), 9.23 (s, 1H), 8.19 (s, 1H), 7.39 (brs, 2H), 6.82 (s, 1H), 6.73 (s, 2H), 5.76 (s, 1H), 5.24 - 5.18 (m, 1H), 4.41 (d, 1H), 4.04 - 3.99 (m, 1H), 3.69 - 3.56 (m, 5H), 3.37 - 3.31 (m, 2H), 2.67 - 2.60 (m, 2H), 2.03 - 1.98 (m, 4H), 1.87 - 1.74 (m, 5H).

[0404] Determine the absolute configurations of Compound 23 and Compound 24: The secondary alcohol of F4-a reacts with a pair of chiral reagents with known absolute configurations to form Mosher esters under the action of a condensing agent; the chiral reagents described in this example are (+)-α-methoxyphenylacetic acid (S-MPA) and (-)-α-methoxyphenylacetic acid (R-MPA). Measure a pair of Mosher esters 1 1H-NMR, and calculate Δδ = δ of the β-H of the substituents on the chiral carbon of the secondary alcohol S -δ RBased on the value, the substituent attached to the β-H with a negative Δδ value is classified as on the left side of the MTPA plane; the substituent attached to the β-H with a positive Δδ value is classified as on the right side of the MTPA plane; thus, the absolute configuration of the F4-a secondary alcohol is determined.

[0405]

[0406] (S)-2-(4,4-Difluorocyclohexyl)-2-((R)-2-methoxy-2-phenylacetoxy) diphenylethyl ester (G1-a)

[0407] Using F4-a (128.0 mg, 0.36 mmol) and (R)-MPA (73.77 mg, 0.44 mmol) as raw materials, they were dissolved in DCM (15 mL). EDCI·HCl (85.11 mg, 0.44 mmol) and DMAP (8.68 mg, 0.07 mmol) were added successively, and the mixture was stirred at room temperature for 6 h. Ethyl acetate was added, and the mixture was washed successively with water and saturated brine, dried over anhydrous sodium sulfate, filtered, and separated by column chromatography with PE:EA (1:3) to obtain a colorless oil G1-a (42.02 mg, 23.25%). 1 H NMR (500 MHz, CDCl3) δ 7.44 - 7.41 (m, 2H), 7.33 - 7.28 (m, 10H), 7.19 - 7.16 (m, 3H), 6.88 (s, 1H), 5.09 (d, J = 4.4 Hz, 1H), 4.84 (s, 1H), 3.43 (s, 3H), 2.03 - 1.98 (m, 3H), 1.54 - 1.30 (m, 6H).

[0408] (S)-2-(4,4-Difluorocyclohexyl)-2-((S)-2-methoxy-2-phenylacetoxy) diphenylethyl ester (G2-a)

[0409] Using F4-a (200.0 mg, 0.55 mmol) and (S)-MPA (115.27 mg, 0.69 mmol) as raw materials, the synthesis method was the same as that of G1-a. After separation, a colorless oil G2-a (126.35 mg, 23.25%) was obtained. 1 H NMR (500 MHz, CDCl3) δ 7.44 - 7.42 (m, 2H), 7.35 - 7.28 (m, 13H), 6.93 (s, 1H), 5.05 (d, J = 4.4 Hz, 1H), 4.87 (s, 1H), 3.40 (s, 3H), 1.96 - 1.87 (m, 3H), 1.57 - 1.29 (m, 6H).

[0410] Based on a pair of Mosher esters of F4-a 1 H-NMR, calculate Δδ = δ of the β-H of the substituent at the chiral carbon of the secondary alcohol S -δ RFor the value, the substituent connected to the β-H with a negative Δδ value is assigned to the left side of the MTPA plane; the substituent connected to the β-H with a positive Δδ value is assigned to the right side of the MTPA plane; thus, the absolute configuration of the F1-a or F4-a secondary alcohol is determined. According to the calculation results, the absolute configuration of the F4-a secondary alcohol is the S configuration. The relevant calculations are as follows:

[0411] Δδ G11-βH = δ G11-βH-(S)-MPA - δ G11-βH-(R)-MPA = 1.91 - 2.02 = -0.29 ppm, indicating that the G11 group is on the left side of the Mosher plane; Δδ G12-βH = δ G12-βH-(S)-MPA - δ G12-βH-(R)-MPA = 6.93 - 6.88 = +0.05 ppm, indicating that the G12 group is on the right side of the Mosher plane.

[0412] (R)-configuration intermediate F1-a is used for the synthesis of Compound 24:

[0413]

[0414] (S)-configuration intermediate F4-a is used for the synthesis of Compound 23:

[0415] Using F1-a (100.0 mg, 0.28 mmol) as the raw material, ultra-dry THF as the solvent, under ice bath conditions, NaOtBu (32.0 mg, 0.33 mmol) was added batch by batch, and the reaction was stirred for 15 min. Then, under ice bath conditions, crushed diphenylphosphorylhydroxylamine (77.65 mg, 0.33 mmol) was added in batches. The subsequent experimental operations were the same as the second step of Example 18, and white solid F6-a (28.2 mg, 27.07%, 99% ee) was obtained by column chromatography. 1 1H NMR (400 MHz, CDCl3) δ 7.40 - 7.28 (m, 10H), 7.00 (s, 1H), 5.66 (s, 2H), 4.15 (d, J = 5.6 Hz, 1H), 2.05 - 1.98 (m, 3H), 1.86 - 1.74 (m, 1H), 1.58 - 1.42 (m, 5H).

[0416] ​

[0417] Using F4-a (100.0 mg, 0.28 mmol) as the raw material, the synthesis method was the same as the method for converting F1-a to F1-6, and white solid F12-a (25.30 mg, 24.29%, 99% ee) was obtained by column chromatography. 11H NMR (600 MHz, CDCl3) δ 7.31 - 7.26 (m, 8H), 7.25 - 7.21 (m, 2H), 6.93 (s, 1H), 5.73 (s, 2H), 4.08 (d, J = 5.7 Hz, 1H), 1.97 - 1.91 (m, 2H), 1.77 - 1.70 (m, 1H), 1.59 - 1.48 (m, 6H).

[0418] Example 25: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid inner salt (Compound 25)

[0419]

[0420] First, dissolve Compound 21 (221.3 mg, 49.06 μmol) in MeOH (0.5 mL), and then dropwise add the above methanol solution into water (25 mL) and stir for 15 min under ice bath conditions. After filtration, a solid powder is obtained, which is vacuum dried at 28 °C for 48 h to obtain Compound 25 (166.8 mg, 85.9%), as a white solid. The residual amount of trifluoroacetate is detected by ion chromatography, and the fluorine peak of trifluoroacetic acid is confirmed to be absent by 19F NMR. 1 1H NMR (500 MHz, DMSO-d6) δ 9.61 (d, J = 7.7 Hz, 1 / 2H), 9.54 (d, J = 8.0 Hz, 1 / 2H), 8.20 (s, 1H), 6.86 (s, 1 / 2H), 6.81 (s, 1 / 2H), 6.74 (s, 2H), 5.79 - 5.69 (m, 1H), 5.23 - 5.19 (m, 1H), 4.44 (d, J = 5.8 Hz, 1 / 2H), 4.31 (d, J = 6.9 Hz, 1 / 2H), 3.74 - 3.57 (m, 4H), 3.40 - 3.28 (m, 2H), 2.70 - 2.59 (m, 2H), 2.00 - 1.72 (m, 7H), 1.44 - 1.36 (m, 2H). 19 19F NMR (471 MHz, DMSO-d6) δ -88.96 - -89.38 (m, 1F), -89.50 - -89.85 (m, 1F).

[0421] Example 26: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid p-toluenesulfonate (Compound 26)

[0422]

[0423] First, dissolve Compound 25 (5.64 mg, 7.00 μmol) in MeOH (0.1 mL). Under ice bath conditions, add dropwise to a methanol solution of p-toluenesulfonic acid (1.21 mg, 7.00 μmol) and stir at the same temperature for 15 min. Concentrate methanol under reduced pressure at room temperature, and vacuum dry the obtained solid at room temperature for 30 min. Then, slurry the obtained solid with methyl tert-butyl ether (4 mL) for 10 min, filter, and vacuum dry at 28 °C for 30 min to obtain white solid Compound 26 (5.80 mg, 99.50%). 1 H NMR (400 MHz, DMSO-d6) δ 9.73 - 9.70 (m, 1 / 2H), 9.70 - 9.65 (m, 1 / 2H), 8.26 - 8.21 (m, 1H), 7.48 (d, J = 7.8 Hz, 2H), 7.12 (d, J = 7.4 Hz, 2H), 6.95 (s, 1 / 2H), 6.91 (s, 1 / 2H), 6.73 (s, 2H), 5.79 - 5.69 (m, 1H), 5.24 - 5.20 (m, 1H), 4.47 (d, J = 5.5 Hz, 1 / 2H), 4.35 (d, J = 6.9 Hz, 1 / 2H), 3.72 - 3.60 (m, 4H), 3.39 - 3.30 (m, 2H), 2.64 (m, 2H), 2.29 (s, 3H), 1.82 (m, 7H), 1.43 (s, 2H).

[0424] Example 27: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-((carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid hydrochloride (Compound 27)

[0425]

[0426] First, dissolve compound 25 (5.30 mg, 6.58 μmol) in MeOH (0.1 mL). Then, dropwise add the above methanol solution into ethyl acetate (2.0 mL). Under ice bath conditions, dropwise add an ethyl acetate solution of 1 M hydrochloric acid (6.58 μL, 6.58 μmol), and stir for 10 min at the same temperature. Concentrate ethyl acetate under reduced pressure at room temperature, and vacuum dry the obtained solid at room temperature for 30 min. Then, slurry the obtained solid with methyl tert-butyl ether (4 mL) for 10 min, filter, and vacuum dry at 28 °C for 30 min to obtain white solid compound 27 (5.80 mg, 99.50%). 1 H NMR (600 MHz, DMSO-d6) δ 10.04 (s, 1H), 9.69 (m, 1 / 2H), 9.63 (m, 1 / 2H), 8.22 (s, 1H), 6.91 (s, 1 / 2H), 6.87 (s, 1 / 2H), 6.76 - 6.72 (m, 3H), 5.77 - 5.70 (m, 1H), 5.21 (m, 1H), 4.46 (d, J = 6.0 Hz, 1 / 2H), 4.33 (d, J = 6.0 Hz, 1 / 2H), 3.72 - 3.69 (m, 4H), 3.35 - 3.32 (m, 2H), 2.65 - 2.61 (m, 2H), 1.98 - 1.81 (m, 7H), 1.43 - 1.40 (m, 2H).

[0427] Example 28: Inner salt of (7R)-7-((Z)-2-(2-amino-5-chlorothiazol-4-yl)-2-(((R)-2-carboxy-1,1,1-trifluoropropan-2-yl)oxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid compound (Compound 28)

[0428]

[0429] Using compound 18 (40.6 mg, 44.25 μmol) as the raw material, according to the synthesis method of Example 25, compound 28 (29.6 mg, 83.3%) was obtained as a white solid. It was confirmed by nuclear magnetic resonance fluorine spectrum that there was no fluorine peak of trifluoroacetic acid. 11H NMR (500 MHz, DMSO-d6) δ 9.98 (s, 1H), 9.70 (d, J = 8.0 Hz, 1H), 9.20 (s, 1H), 8.20 (s, 1H), 7.43 (s, 2H), 6.74 (s, 2H), 5.75 - 5.71 (m, 1H), 5.18 (d, J = 4.4 Hz, 1H), 3.70 - 3.59 (m, 4H), 3.38 - 3.31 (m, 2H), 2.70 - 2.60 (m, 2H), 1.67 (s, 3H).

[0430] Example 29: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((R)-1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid inner salt (Compound 29)

[0431]

[0432] Using compound 24 (45 mg, 49.06 μmol) as the starting material, according to the synthesis method of Example 25, compound 29 (35 mg, 88.6%) was obtained as a white solid. The absence of the fluorine peak of trifluoroacetic acid was confirmed by 19F NMR. 1 1H NMR (500 MHz, DMSO-d6) δ 9.96 (s, 1H), 9.49 (d, J = 8.1 Hz, 1H), 9.20 (s, 1H), 8.20 (s, 1H), 7.26 (s, 2H), 6.78 (s, 1H), 5.80 - 5.73 (m, 1H), 5.20 (d, J = 4.5 Hz, 1H), 4.39 (d, J = 5.6 Hz, 1H), 3.72 - 3.62 (m, 4H), 3.33 - 3.29 (m, 2H), 2.68 - 2.59 (m, 2H), 2.02 - 1.75 (m, 9H). 19 19F NMR (471 MHz, DMSO-d6) 19F NMR (753 MHz, DMSO-d6) δ -89.17 (s, 2F), -89.48 (s, 2F).

[0433] Example 30: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((R)-1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid p-toluenesulfonate (Compound 30)

[0434]

[0435] Using Compound 29 (25 mg, 31.05 μmol) as the starting material, according to the synthesis method of Example 26, Compound 30 (23.7 mg, 78.1%) was obtained. 1 1H NMR (600 MHz, DMSO-d6) δ 9.67 (s, 1H), 8.24 - 8.18 (m, 1H), 7.48 (d, J = 7.5 Hz, 2H), 7.12 (d, J = 7.7 Hz, 2H), 6.97 (d, J = 10.8 Hz, 1H), 6.73 (s, 2H), 5.78 - 5.74 (m, 1H), 5.22 (d, J = 4.7 Hz, 1H), 4.47 (s, 1H), 3.75 - 3.63 (m, 4H), 3.59 (d, J = 17.5 Hz, 1H), 3.40 - 3.29 (m, 2H), 2.64 (m, 2H), 2.29 (s, 3H), 2.06 - 1.97 (m, 3H), 1.91 - 1.72 (m, 4H), 1.50 - 1.38 (m, 2H).

[0436] Example 31: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((R)-1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid disodium salt (Compound 31)

[0437]

[0438] First, the inner salt of Compound 29 (4.32 mg, 6.47 μmol) was dissolved in anhydrous methanol (0.1 mL). Under ice bath conditions, an aqueous sodium hydroxide solution (0.43 mg, 10.73 μmol) was added dropwise, and the mixture was stirred for 3 minutes. The reaction system was freeze-dried under vacuum for 24 h to obtain a white fluffy solid, Compound 31 (4.22 mg, 92.63%). 11H NMR (500 MHz, DMSO-d6) δ 11.62 (s, 1H), 7.73 (s, 1H), 6.76 (s, 1H), 6.38 (d, J = 7.9 Hz, 1H), 6.27 (d, J = 7.6 Hz, 1H), 5.56 (d, J = 5.0 Hz, 1H), 4.99 (d, J = 4.7 Hz, 1H), 4.24 (d, J = 4.3 Hz, 1H), 3.91 (d, J = 12.6 Hz, 1H), 3.54 (d, J = 17.0 Hz, 1H), 3.42 (d, J = 12.8 Hz, 1H), 3.26 (d, J = 17.2 Hz, 1H), 2.63 - 2.61 (m, 2H), 2.54 - 2.53 (m, 4H), 2.01 - 1.93 (m, 4H), 1.82 - 1.77 (m, 3H), 1.51 - 1.45 (m, 2H).

[0439] Example 32: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((R)-1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid monosodium salt (Compound 32)

[0440]

[0441] First, dissolve Compound 29 (5.21 mg, 6.47 μmol) in anhydrous methanol (0.1 mL). Under ice bath conditions, dropwise add it to an aqueous sodium hydroxide solution (0.26 mg, 6.47 μmol), and stir for 10 min. Lyophilize the reaction system under vacuum for 24 h to obtain white fluffy solid Compound 32 (5.32 mg, 99.40%). 1 1H NMR (500 MHz, DMSO-d6) δ 8.31 (s, 1H), 7.17 (s, 2H), 6.93 (d, J = 8.1 Hz, 1H), 6.77 (s, 1H), 6.74 (d, J = 8.2 Hz, 1H), 5.65 - 5.61 (m, 1H), 5.04 (d, J = 4.7 Hz, 1H), 4.31 (d, J = 4.2 Hz, 1H), 3.74 (d, J = 13.0 Hz, 1H), 3.58 - 3.51 (m, 2H), 3.36 - 3.31 (m, 4H), 3.17 (s, 1H), 2.73 - 2.58 (m, 2H), 2.01 - 1.94 (m, 3H), 1.83 - 1.69 (m, 4H), 1.52 - 1.44 (m, 2H).

[0442] Example 33: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((S)-1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid inner salt (Compound 33)

[0443]

[0444] Using Compound 23 (30.00 mg, 37.26 μmol) as the starting material, according to the synthesis method of Example 29, Compound 33 (25.32 mg, 84.40%) was obtained as a white solid. The fluorine peak of trifluoroacetic acid was not observed in the 19F NMR spectrum, which was confirmed. 1 H NMR (500 MHz, DMSO-d6) δ 9.96 (s, 1H), 9.57 (d, J = 7.7 Hz, 1H), 9.20 (s, 1H), 8.21 (s, 1H), 7.27 (s, 2H), 6.73 (s, 3H), 5.73 - 5.71 (m, 1H), 5.21 - 5.19 (m, 1H), 4.25 (d, J = 6.8 Hz, 1H), 3.69 - 3.62 (m, 4H), 3.31 - 3.28 (m, 2H), 2.68 - 2.63 (m, 2H), 1.95 - 1.75 (m, 7H), 1.42 - 1.37 (m, 2H). 19 F NMR (471 MHz, DMSO-d6) δ -89.26 (s, 2F), -89.75 (s, 2F).

[0445] Example 34: (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((S)-1-carboxy-2-(4,4-difluoro)cyclohexyloxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid p-toluenesulfonate (Compound 34)

[0446]

[0447] First, dissolve compound 33 (41.5 mg, 51.54 μmol) in anhydrous methanol (0.2 mL). Under ice bath conditions, add it dropwise to a methanol solution of p-toluenesulfonic acid (8.87 mg, 51.54 μmol), and stir for 15 min. Concentrate methanol under reduced pressure at room temperature, and vacuum dry the obtained solid at room temperature for 30 min. Then suspend the obtained powder in methyl tert-butyl ether, slurry for 20 min, filter, and dry to obtain the corresponding p-toluenesulfonate compound 34 (37.4 mg, 74.3%). 1 H NMR (600 MHz, DMSO-d6) δ 9.67 (s, 1H), 8.24 - 8.18 (m, 1H), 7.48 (d, J = 7.5 Hz, 2H), 7.12 (d, J = 7.7 Hz, 2H), 6.97 (d, J = 10.8 Hz, 1H), 6.73 (s, 2H), 5.78 - 5.74 (m, 1H), 5.22 (d, J = 4.7 Hz, 1H), 4.47 (s, 1H), 3.75 - 3.63 (m, 3H), 3.59 (d, J = 17.5 Hz, 1H), 3.40 - 3.29 (m, 2H), 2.64 (m, 2H), 2.29 (s, 3H), 2.06 - 1.97 (m, 3H), 1.91 - 1.72 (m, 4H), 1.50 - 1.38 (m, 2H).

[0448] Biological evaluation

[0449] The present invention will be further described below in conjunction with test examples, but these examples do not mean to limit the scope of the present invention.

[0450] Test example 1 Stability of the compound of the present invention in CAMHB medium

[0451] Due to the introduction of a quaternary ammonium salt fragment in the structure of cefiderocol, this part results in its unstable physicochemical properties, which is not conducive to the synthesis, storage, and use of the compound. Therefore, the stability of the compound of this patent and cefiderocol in CAMHB broth was investigated. The following table shows the stability investigation results of compound 32 and cefiderocol in CAMHB broth under different pH (pH = 7) conditions. Among them, under the HPLC test conditions of cefiderocol, some matrix peaks of CAMHB coincide with its impurity peaks.

[0452] Table 1 Stability of compound 32 in CAMHB (OXOID) broth at pH = 7 (37 °C)

[0453]

[0454] As shown in Table 1, the compound 32 of the present invention has good stability (the HPLC purity only decreases by 0.395%) after incubation at 37 °C for 20 h in CAMHB broth at pH = 7, which is significantly better than that of cefiderocol (the HPLC purity decreases by up to 8.627%). The significant improvement in the stability of the compound of the present invention may be due to its special side chain structure different from that of the quaternary ammonium salt of cefiderocol.

[0455] Test Example 2 Experiment on antibacterial activity in vitro.

[0456] 2.1 In vitro antibacterial test of the preferred compounds in CAMHB medium

[0457] 2.1.1 Test strains

[0458] 2.1.1.1 Clinical pathogenic bacteria collected in Sichuan region and Beijing region in recent years

[0459] The test clinical isolated strains selected for in vitro antibacterial activity screening are shown in Table 1:

[0460] Table 2 Test clinical isolated strains for in vitro antibacterial activity screening

[0461]

[0462] The above strains were identified by the VITEK-60 automatic microbial identifier in the collection unit and then re-identified by the conventional method in our laboratory. Each strain of bacteria was subcultured to obtain single colonies on an agar plate before the experiment, and the bacteria cultured overnight at 37 °C were appropriately diluted for the experiment.

[0463] 2.1.2 Culture medium and culture conditions:

[0464] Culture medium: CAMHB (OXOID)

[0465] Culture conditions: Incubate at 35 - 37 °C for 16 - 20 h and observe the results.

[0466] 2.1.3 In vitro antibacterial test method

[0467] The microbroth dilution method recommended by the Antimicrobial Susceptibility Testing Procedure of the Clinical and Laboratory Standards Institute (CLSI) M07-A11 was used to determine the MIC values of each test sample against the test strains in CAMHB medium.

[0468] 1.1.4 Determine the MIC in CAMHB medium

[0469] Weigh an appropriate amount of the test sample powder. According to the solubility of the sample, dissolve the sample with sterile pure water or dimethyl sulfoxide to make the concentration of the stock solution 1.28 mg / mL. Take an appropriate amount of the stock solution and dilute it tenfold with sterile broth to 0.128 mg / mL. Aliquot half of the volume of the drug solution into a 96-well sample addition slot, and dilute the other half of the volume of the drug solution twofold with sterile broth and then add it to a deep-well sample addition slot. Repeat the above steps to make the drug concentrations in the sample addition slots 128, 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, 0.06 mg / L, respectively, and use it freshly prepared.

[0470] Pick several colonies from the agar plates cultured for 18 - 24 h and directly make a bacterial suspension in sterile physiological saline, and adjust the concentration of the bacterial suspension to 0.5 McFarland unit. Dilute the calibrated bacterial solution with CAMHB broth to (4 - 8)×10 5 CFU / mL, and use it freshly prepared.

[0471] Respectively pipette 100 μL of the above-mentioned test sample solutions with different concentrations into wells 1 to 12 of a sterile 96-well polystyrene plate, and add 100 μL of the above-mentioned inoculum to each well. The final concentrations of the test samples in the wells are 64, 32, 16, 8, 4, 2, 1, 0.5, 0.25, 0.125, 0.06, 0.03 mg / L, respectively, and the final inoculum concentration is (2 - 4)×10 5 CFU / mL. Additionally, set up growth control wells, each containing 100 μL of inoculum and 100 μL of sterile broth. After mixing the test substances and the inoculum in each well, seal them and place them in an incubator at 35 - 37 °C for 18 - 20 h, and then read the results. Use a microplate reader (model: Multiskan FC; manufacturer: THERMOFISHER) to measure the OD600 value. MIC endpoint determination: After the culture is completed, observe the growth of bacteria in each well. The lowest drug concentration that completely inhibits the growth of bacteria in the well is its minimum inhibitory concentration (Minimal Inhibitory Concentration, MIC).

[0472] 2.1.5 Experimental results of the in vitro anti-multidrug-resistant Gram-negative bacteria of some preferred compounds

[0473] The positive control drugs shown in Table 3 are cefiderocol and meropenem, and the in vitro activity test results of some compounds of the present invention. Among them, meropenem is a marketed carbapenem drug.

[0474] Table 3 In vitro antibacterial activity experimental results of some compounds of the present invention (unit: μg / L)

[0475]

[0476] aEco: Escherichia coli. The standard strain of Escherichia coli ATCC 35218 was purchased from the American Type Culture Collection. b Kpn: Klebsiella pneumonia. c Aba: Acinetobacter baumannii. d Pae: Pseudomonas aeruginosa. e C: Cefiderocol. f M: Meropenem.

[0477] As can be seen from Table 3, the representative compounds of the present invention have good in vitro antibacterial activity. The antibacterial activities against Gram-negative bacteria Klebsiella pneumonia, Acinetobacter baumannii, and Pseudomonas aeruginosa that are clinically isolated and resistant to meropenem are significantly better than those of the existing positive control drug cefiderocol, and the bacteriostatic effect against Escherichia coli is comparable to that of cefiderocol. In particular, the antibacterial capabilities of Compounds 4, 11, 12, 13, 14, 21, 22, 23, 24, 25, and 27 against Klebsiella pneumonia that is clinically isolated and resistant to meropenem are increased by 8 - 64 times, 8 - 32 times, 4 - 32 times, 2 - 64 times, 2 - 128 times, 4 - 32 times, 4 - 128 times, 8 - 64 times, 8 - 64 times, and 4 - 64 times respectively compared with cefiderocol; the antibacterial activities against Acinetobacter baumannii are increased by 8 times, 4 times, 4 times, 4 times, 4 times, 4 times, 16 times, 32 times, 8 times, and 4 times respectively; the activities against Pseudomonas aeruginosa are increased by 4 times, 2 times, 2 - 8 times, 2 - 8 times, 2 - 8 times, 1 - 4 times, 4 - 8 times, 4 - 33 times, 2 - 8 times, and 2 - 8 times respectively.

[0478] Due to the novel structure, the compounds of the present invention overcome the defect that cefiderocol has weak antibacterial activity against Klebsiella pneumonia, Acinetobacter baumannii, and Pseudomonas aeruginosa. The compounds of the present invention have a novel structure and great development value.

[0479] Table 4 Structures and Related In Vitro Antibacterial Activity Experimental Results of Some Compounds of the Present Invention (Unit: μg / L)

[0480]

[0481]

[0482] a Eco: Escherichia coli. bAba: Acinetobacter baumannii. c Kpn: Klebsiella pneumoniae d Pae: Pseudomonas aeruginosa. Pae ATCC 27853 is the standard strain of Pseudomonas aeruginosa and was purchased from the American Type Culture Collection. e M: Meropenem

[0483] (Meropenem). f C: Cefiderocol.

[0484] The synthesis of Compounds 35 - 36 was carried out with reference to the synthesis method of Compound 22, and the relevant NMR data are shown below:

[0485] Example 35 (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((2-carboxypropan-2-yl)oxy)imino)acetamido)-3-(((2-(2-chloro-3,4-dihydroxybenzamido)ethyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (Compound 35) 1 H NMR (500 MHz, DMSO-d6) δ 9.46 (d, J = 8.4 Hz, 1H), 8.19 (t, J = 5.7 Hz, 1H), 6.80 (s, 1H), 6.73 (s, 3H), 5.79 (dd, J = 8.3, 4.8 Hz, 1H), 5.22 (d, J = 4.7 Hz, 1H), 3.75 - 3.56 (m, 4H), 3.41 - 3.29 (m, 2H), 2.71 - 2.59 (m, 2H), 1.47 (s, 3H), 1.46 (s, 3H).

[0486] Example 36 (6R,7R)-7-((Z)-2-(2-Aminothiazol-4-yl)-2-(((2-carboxypropan-2-yl)oxy)imino)acetamido)-3-(((3-(2-chloro-3,4-dihydroxybenzamido)propyl)thio)methyl)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (Compound 36) 11H NMR (500 MHz, DMSO-d6) δ 9.46 (d, J = 8.2 Hz, 1H), 8.11 (t, J = 10.4 Hz, 1H), 6.79 (s, 1H), 6.75 - 6.69 (m, 2H), 5.78 (dd, J = 8.1, 4.7 Hz, 1H), 5.21 (d, J = 4.7 Hz, 1H), 3.74 - 3.54 (m, 4H), 3.29 - 3.17 (m, 2H), 2.58 - 2.49 (m, 2H), 1.78 - 1.64 (m, 2H), 1.47 (s, 3H), 1.46 (s, 3H).

[0487] All documents mentioned in this invention are cited herein as references, as if each document was individually cited as a reference. In addition, it should be understood that after reading the above teachings of this invention, those skilled in the art can make various changes or modifications to this invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A compound or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomeric mixture thereof, characterized in that, The compound described above is shown in Formula A; wherein, n1 is 1 or 2; n2 is 1 or 2; X is CR 1 or N; R 1 selected from the group consisting of hydrogen, a halogen (such as F, Cl, Br or I), a C1-C4 alkyl group (such as a methyl group), a C1-C4 haloalkyl group (such as a trifluoromethyl group), a C1-C3 alkoxy group (-O-C1-C3 alkyl), and a C1-C3 alkylthio group (-S-C1-C3 alkyl); R 2A and R 2B are each independently selected from the group consisting of: hydrogen, substituted or unsubstituted C1-C9 alkyl, C1-C4 haloalkyl (such as trifluoromethyl), substituted or unsubstituted C3-C 12 cycloalkyl, and substituted or unsubstituted 4- to 12-membered heterocyclic group; or, R 2A and R 2B together with the carbon atom to which they are attached form a substituted or unsubstituted C3-C 12 cycloalkyl or a substituted or unsubstituted 4- to 12-membered heterocyclic group; R 2A and R 2B In, the substitution means that one or more hydrogens in the group are substituted by R 2S and R 2S are each independently selected from the group consisting of: halogen, sulfone, sulfoxide, hydroxyl, carboxyl, C1-C6 alkyl, oxo (=O); or, two Rs 2S connected to the same atom or adjacent atoms together with the connected atoms form a substituted or unsubstituted C3-C6 cycloalkyl or a substituted or unsubstituted 4- to 6-membered heterocyclic group; R 2S In, the substitution means being substituted by one or more substituents selected from the group consisting of: hydrogen, halogen, C1-C4 alkyl, C1-C4 haloalkyl; R 2 Selected from the group consisting of hydrogen, halogen, nitro, and cyano.

2. The compound or its pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture according to claim 1, characterized in that, The compound described above is shown in Formula I; X is CR 1 or N; R 1 selected from the group consisting of hydrogen, a halogen (such as F, Cl, Br or I), a C1-C4 alkyl group (such as a methyl group), a C1-C4 haloalkyl group (such as a trifluoromethyl group), a C1-C3 alkoxy group (-O-C1-C3 alkyl), and a C1-C3 alkylthio group (-S-C1-C3 alkyl); R 2A and R 2B each independently selected from the group consisting of: hydrogen, substituted or unsubstituted C1-C9 alkyl, C1-C4 haloalkyl (such as trifluoromethyl), substituted or unsubstituted C3-C 12 cycloalkyl, and substituted or unsubstituted 4- to 12-membered heterocyclic group; or, R 2A and R 2B together with the carbon atom to which they are attached form a substituted or unsubstituted C3-C 12 cycloalkyl or substituted or unsubstituted 4- to 12-membered heterocyclic group; R 2A and R 2B In, the substitution means that one or more hydrogens in the group are substituted by R 2S and R 2S each independently selected from the group consisting of: halogen, sulfone, sulfoxide, hydroxyl, carboxyl, C1-C6 alkyl, oxo(=O); or, two Rs 2S connected to the same atom or adjacent atoms together with the connected atoms form a substituted or unsubstituted C3-C6 cycloalkyl or a substituted or unsubstituted 4- to 6-membered heterocyclic group; R 2S In, the substitution means being substituted by one or more substituents selected from the group consisting of: hydrogen, halogen, C1-C4 alkyl, C1-C4 haloalkyl; R 2 Selected from the group consisting of hydrogen, halogen, nitro, and cyano.

3. The compound or its pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture according to claim 1 or 2, characterized in that, Selected from the group consisting of:

4. The compound or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture thereof according to claim 2, characterized in that, The compound is shown in Formula (I-b) or Formula (I-c); Among them, α represents the carbon atom at this position (i.e., the carbon atom 2A connected to R 2B and R 2A ), which is a chiral carbon atom or an achiral carbon atom, and X, R 2B , R 2 are defined as in Formula I.

5. The compound or its pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture according to claim 1, characterized in that, The compound is selected from Table A Table A 6. The compound or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture thereof according to claim 1, characterized in that, Selected from Table B: Table B 7. A pharmaceutical composition, characterized in that, The composition comprises: (a) one or more compounds as described in any one of claims 1-6 or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture thereof; and (b) a pharmaceutically acceptable carrier.

8. Use of a compound as described in any one of claims 1-6 or a pharmaceutically acceptable salt, racemate, tautomer, optical isomer or isomer mixture thereof, or the pharmaceutical composition as described in claim 7 in the preparation of a medicament for treating or preventing infectious diseases caused by pathogenic bacteria.

9. The use according to claim 8, wherein, The pathogenic bacteria are Gram-negative bacteria.

10. The use according to claim 8, characterized in that, The pathogenic bacteria are selected from the group consisting of Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Acinetobacter baumannii.

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