阅读说明：本技术 合成单保护双官能前药的方法和基于其的抗体药物缀合物以及制备抗体药物缀合物的方法 (Method for synthesizing mono-protected bifunctional prodrugs and antibody drug conjugates based thereon and method for preparing antibody drug conjugates ) 是由 L·F·蒂策 于 2018-08-10 设计创作，主要内容包括：本发明涉及用于制备抗体药物缀合物(ADC)的化合物的合成方法,所述化合物即基于倍癌霉素类似物的单保护二聚双官能前药。在另一方面,提供了通过根据本发明的方法获得的化合物。单保护双官能前药用于制备由抗体部分和单保护双官能前药组成的抗体药物偶联物。提供了由此获得的抗体化合物缀合物。此外,提供了一种制备由两个相同或两个不同的抗体部分组成的抗体药物缀合物的方法,以及相应地包含两个不同的抗体部分的抗体化合物缀合物。这些缀合物可以用于药物组合物中,特别是用于治疗肿瘤,例如用于ADC治疗。(The present invention relates to a method of synthesis of compounds, i.e. mono-protected dimeric bifunctional prodrugs based on duocarmycin analogs, for the preparation of Antibody Drug Conjugates (ADCs). In another aspect, there is provided a compound obtained by the process according to the invention. The mono-protected bifunctional prodrugs are useful for preparing antibody drug conjugates consisting of an antibody moiety and a mono-protected bifunctional prodrug. Antibody compound conjugates thus obtained are provided. Furthermore, a method of preparing an antibody drug conjugate consisting of two identical or two different antibody moieties is provided, as well as antibody compound conjugates comprising two different antibody moieties accordingly. These conjugates can be used in pharmaceutical compositions, in particular for the treatment of tumors, e.g. for ADC therapy.)

1. Synthesis method of compound of general formula I

Wherein Hal is F, Cl, Br or I;

r is H or optionally substituted C₁-C₄Alkyl, optionally substituted C₁-C₄Alkoxy, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted C₁-C₄Alkylcarboxy C₁-C₄Alkyl, Hal, CN, optionally substituted C₁-C₄Alkylsulfonyl, optionallySubstituted arylsulfonyl, or NR as defined below_zA group;

R₁is H or C₁-C₄Alkyl or C₁-C₄An alkoxy group;

X₁is a protecting group;

l is a linking group for covalent attachment, wherein L has the general structure Z-Y-Z';

z and Z' are independently selected from C-O, OC-O, SO₂、NRz、NR₂C＝O、C＝ONR_zWherein each R is_zIndependently of one another, selected from H, optionally substituted C₁-C₄Alkyl or optionally substituted C₁-C₄An acyl group;

wherein Y is optionally substituted C₁-C₁₀Alkyl, groups of structure VIII:

wherein o and p are independently selected from integers of 1 to 20, wherein o and p may be the same or different integers, X₃Is i) N, S or O, or ii) aryl or heteroaryl, wherein [ C (R)_a)₂]_OAnd [ C (R)_a)₂]_pIs present in the meta position to the aryl or the heteroaryl group,

each R_AIndependently of one another, from H or optionally substituted C₁-C₄Alkyl or optionally substituted C₁-C₄An acyl group;

comprising reacting a compound of formula II

R, R therein₁And Hal is as defined above, and X₂Can be reacted with the above X₁The same or different protecting group, a step of reaction with a deprotecting agent, thereby converting X of the compound of formula II₂Group deprotection;

subsequently, reacting the deprotected compound of formula II with a compound of formula III in the presence of a coupling agent and a base to obtain a compound of formula I

Wherein the substituents Hal, R₁、X₁And R is as defined above and L is a linking group as defined above, R₃Selected from Hal (especially Cl and Br) or OH.

2. The method of claim 1, wherein X is₁And X₂Independently of one another, are selected from the following functional groups: t-butyloxycarbonyl, benzyloxycarbonyl, tosyl, nitrophenyl, trimethylsilyl, dimethyl-t-butylsilyl, a protected monosaccharide, disaccharide or trisaccharide, including β -D-galactoside, β -D-glucuronic acid, β -D-glucoside, α -D-mannoside, fucose, a carbamate-containing moiety, an acetal-containing moiety or an ether-containing moiety cleavable by oxidation.

3. A process according to claim 1 or 2, wherein Hal is Cl and/or R₁Is H, and/or wherein R is H.

4. The method according to any one of the preceding claims, wherein X is₂Is tert-butoxycarbonyl, and X₁Is tetraacetyl-beta-D-galactoside.

5. A process according to any of the preceding claims, characterized in that the base is selected from diisopropylethylamine, triethylamine, pyridine.

6. The method according to any of the preceding claims, characterized in that the coupling agent is a phosphonium reagent.

7. The process according to any one of the preceding claims, wherein L has the general structure VI

Wherein n is an integer from 1 to 10.

8. A process according to any one of the preceding claims, wherein the compound of formula III is obtained by reacting a compound of formula IV with a compound of formula VII

Wherein X₁、X₄、R、R₁And Hal is as defined above, X₄Is as in X₁A protecting group as defined, and X₁And X₄Different from each other, the compounds of the formula VII are

VII R₅–L–R₆

Wherein L is Z-Y-Z 'and wherein Z, Y and Z' are as defined above, R₅And R₆Independently of one another, from halogen, (e.g. Cl or Br) or OH groups.

Whereby in a first step a compound of formula IV is reacted with a deprotecting agent whereby the compound is at X₄Deprotection of the group, followed by,

reacting the deprotected compound of formula iv with a compound of formula VII in the presence of a base to give a compound of formula iii.

9. A compound of formula I obtainable by a process according to any one of claims 1 to 8.

10. A process for the preparation of an antibody drug conjugate consisting of an antibody moiety and a compound according to formula I (in particular a compound of formula I according to claim 9), comprising the steps of: coupling an antibody moiety to a compound of formula I via a free OH group at the 5-position of the benzindolyl of formula I,

alternatively, for X₁Radicals or present in X₁The protecting group on (a) is deprotected.

11. An antibody compound conjugate obtainable by the method of claim 10.

12. A process for the preparation of an antibody drug conjugate consisting of two identical or two different antibody moieties and a compound of formula I as defined herein, said process comprising the steps of:

providing a compound according to claim 11,

optionally, X is deprotected with a deprotecting agent₁Radicals or present in X₁The protecting group on (a) is deprotected.

By deprotecting the OH group in position 5 of the benzindolyl group of formula I, or X if present₁By deprotecting X₁A protecting group coupling a second antibody moiety to the antibody drug conjugate of claim 11.

13. An antibody compound conjugate obtainable by the method according to claim 12, comprising two different antibody moieties.

14. A pharmaceutical composition comprising a compound according to claim 10 or an antibody compound conjugate according to claim 11 or 13.

15. Use of a compound of formula I for the preparation of an Antibody Drug Conjugate (ADC).

Prior Art

Individual treatment concepts are required for various forms of cancer disease. To cope with the complexity of tumor diseases, most of the clinically applied treatments today represent a combination of different treatments. Surgical resection is a possible method of choice in cases where surgery is accessible and the tumor is well defined. However, if the tumor is more difficult to access or affect important structures, radiation therapy as well as chemotherapy is the method of choice. Chemotherapy is usually given immediately at a more advanced stage when metastasis has occurred or at least is at risk. In addition, hormone therapy, immunotherapy, and therapy using angiogenesis inhibitors and kinase inhibitors are used for tumor treatment.

Indeed, chemotherapy is currently the most important treatment for metastatic or systemic tumors, although it is often associated with serious side effects, such as hemogram abnormalities, immunodeficiency, mucositis, fever, nausea, vomiting. That is, most chemotherapeutic agents are distributed throughout the body through the blood circulation, so they can reach all cells. However, chemotherapeutic agents typically act systemically on human cells, i.e., they prevent cell proliferation or exert cytotoxicity that may lead to cell death. Generally, chemotherapeutic agents are unable to distinguish between cancer cells and normal cells. The difference is that tumor cells are rapidly proliferating cell types, while normal cells are slowly proliferating cells. However, serious side effects occur because rapidly growing non-tumor cells of the subject, particularly non-tumor cells of bone marrow, hair roots and intestinal epithelial cells, are also affected. One example of a cytotoxic agent for use in chemotherapy includes an alkylating agent. Alkylating agents are a large group of very reactive species that differ significantly in structure. In some cases, after pre-activation of a drug or prodrug to a carbenium ion, the active compound will react as an electrophile, particularly with a nucleic acid, to form a covalent bond. Thus, cross-linking of DNA, abnormal base pairing or strand breakage occurs, preventing replication and ultimately leading to cell death. Typical examples of alkylating agents are cyclophosphamide and also cisplatin. One group of particularly useful alkylating agents includes the natural antibiotics CC1065, Cyclopropylpyrroloindole (CPI) derivatives, duocarmycins and Cyclopropylphenylindolin (CBI) derivatives, yatekemycin, as well as derivatives and analogs of such natural prodrugs. Due to the necessity of chemotherapy, the strong side effects of most clinically used drugs, and the emergence of resistance to many known chemotherapeutic agents, continued development in the area of chemotherapeutic agents is essential.

To reduce side effects in chemotherapy, new concepts have been developed that exploit the genotypic and phenotypic properties of tumor cells and target activation of reversible prodrugs directly on the side of action. This targeted activation is seen in the so-called ADEPT concept (antibody-directed enzyme prodrug therapy). In this case, the non-toxic prodrug is directly converted to the drug in the tumor using an antibody enzyme aggregate, and higher selectivity is achieved. This binary therapy involves two steps. First, a quantity of abzyme conjugate is applied and then distributed throughout the organism by blood circulation.

The conjugate binds to a specific antigen on the surface of the tumor cell or is degraded or excreted by the body. If unbound abzyme aggregates can no longer be detected, the use of the prodrug takes place in a second step. Usually non-toxic prodrugs are also distributed throughout the organism and selectively exert a toxic effect in tumor tissue by enzymes present only on the tumor surface in the form of antibody enzyme aggregates. The released drug exhibits toxic effects after penetrating the cell membrane, while the enzyme remains active on the outside of the tumor cell and can activate other prodrug molecules. During this method, the prodrug should not be cleaved by body-specific enzyme systems, otherwise the therapeutic activity would be reduced or eliminated. However, these advantages of the previously known prodrugs are that the difference in cytotoxicity (QIC50) between the prodrug and the drug produced therefrom is too small, and that the cytotoxicity is too low for the drug it forms (IC 50).

As a guideline: in the presence of an enzyme, the QIC50 value for the prodrug should be greater than 1000, and the cytotoxic IC50 value for the base drug should be less than 10 nM.

Clinical studies have been conducted on the ADEPT concept. The ADEPT concept has been shown to be applicable to selective tumour therapy, but improvements in various aspects are still needed to enable selective and effective therapy.

Another approach to targeted therapy of malignancies is prodrug monotherapy. In this approach, the presence of an enzyme overexpressed in the tumor is required, which is capable of cleaving to release the corresponding prodrug of the corresponding drug. An example of such a possible enzyme is β -D-glucuronidase, which can be detected in increased concentrations in necrotic areas of tumor tissue. Alternatively, conjugates of drugs and tumor-specific ligands may also be used for selective targeting in cancer therapy. One of the problems to be improved is to provide a novel potent prodrug which has a high difference in cytotoxicity between the prodrug and the corresponding drug, a high cytotoxicity of the drug and a short plasma median time. In addition, there is a need for novel bifunctional prodrugs based on duocarmycin analogs for ADC therapy (antibody drug conjugates).

ADCs are an important class of highly potent biopharmaceuticals designed as targeted therapeutics for the treatment of subjects suffering from, for example, cancer. In ADCs, an antibody is attached to a biologically active ingredient (also known as a payload or prodrug/drug). The drug may be in the form of a prodrug that is converted to the active ingredient in the target cell, or may be a drug that is effective upon binding to the target.

With ADC, the targeting ability of a monoclonal antibody is coupled with the cytotoxic activity of an active agent or a precursor of said active agent. Due to the specificity of monoclonal antibodies, it is possible to target cancer cells directly. Thus, it is possible to treat cancer cells more effectively with less side effects on healthy cells.

Although some ADC products are already on the market, ADC drugs are expected to have great potential. Cleavable and non-cleavable linkers are present for linking the antibody moiety to the anticancer agent or an active ingredient thereof or a precursor thereof. However, the linkage may affect the toxicity of the active ingredient.

Various embodiments for attaching antibody moieties or other binding partners to a payload, particularly a CBI component, have been described in the art.

For example, WO 2009/017394 describes substituted CC-1065 analogs and conjugates thereof. Other bifunctional compounds are described, for example, in DE 102015118490, identifying novel bifunctional prodrugs and drugs based on CC-1065 analogs.

Tietze, L.F. et al, chem.Eur.J.2013,19,1726-1731 describe photoactivatable prodrugs of highly potent duocarmycin analogs for selective cancer therapy. Among other things, photochemical activation protocols for dimeric dibasic drugs (seco-drug) are provided. A theoretical reaction scheme is given showing the intermediate theoretical compound 16 of a mono-protected bifunctional prodrug. Notably, shown is the theoretical reaction of a bifunctional prodrug with a binary drug via a theoretical intermediate of the mono-binary drug. The mono-binary drug shown in this scheme has only theoretical properties, since the reaction will go directly from the bifunctional prodrug to the binary drug when radiation is applied. Thus, compound 16, the mono-binary drug, was not isolated or characterized. As shown in this scheme, it is not possible to selectively cleave only one protecting group of a bifunctional product, but this reaction directly produces a binary drug, as shown in scheme 4, which immediately reacts further with drug 18.

However, bifunctional compounds described in the art are symmetrically attached to a binding entity, such as an antibody, i.e. on both CBI subunits of the bifunctional compound. However, it is desirable to provide bifunctional prodrugs with different functional groups on the two conjugated sides of the two subunits.

Brief description of the invention

It is an object of the present invention to provide novel bifunctional prodrugs based on duocarmycin analogs for ADC therapy, which allow for heterologous derivatization suitable for ADC therapy.

The invention accordingly describes the synthesis of said analogues for ADC therapy. It has been recognized that it is possible to conjugate an antibody on one subunit of a bifunctional prodrug, thus, achieving a linkage to at least one of the two OH groups, while the other OH group, which is essential for the winstein cyclisation required for the conversion of the prodrug into the active drug, can be used for other purposes. Thus, it is possible to provide a bifunctional prodrug comprising the necessary moieties to allow subsequent winstein cyclisation, to which an antibody or any binding moiety is attached on the second OH group of the second subunit. Furthermore, it is envisaged that conjugation to functional groups differently to provide a heterobifunctional prodrug would enable warm cyclization of the two CBI subunits at different time points.

The compounds according to the invention do not require the introduction of any additional functional groups on the payload or drug to attach, for example, antibodies. In contrast to the teaching of DE 102015118490, the binding to the binding moiety (e.g. antibody) is not in the linker moiety, but on at least one of the two subunits of the prodrug.

Brief description of the drawings

Scheme 1: scheme 1 shows the reaction according to the process of the present invention to obtain the compounds of general formula I.

Detailed description of the invention

The present inventors have aimed at providing a method for synthesizing novel intermediates and prodrugs of compounds suitable for cancer therapy.

In a first aspect, there is provided a process for the synthesis of compounds of formula I

Wherein Hal is F, Cl, Br or I;

r is H or optionally substituted C₁-C₄Alkyl, optionally substituted C₁-C₄Alkoxy, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted C₁-C₄Alkylcarboxy C₁-C₄Alkyl, Hal, CN, optionally substituted C₁-C₄Alkylsulfonyl, arylsulfonyl optionally substituted, or NR as defined below_zA group;

R₁is H or C₁-C₄Alkyl or C₁-C₄An alkoxy group;

X₁is a protecting group;

l is a linking group for covalent attachment, wherein L has the general structure Z-Y-Z';

z and Z' are independently selected from C-O, OC-O, SO₂、NRz、NR₂C＝O、C＝O NR_zWherein each R is_zIndependently of one another, selected from H, optionally substituted C₁-C₄Alkyl or optionally substituted C₁-C₄An acyl group; wherein Y is optionally substituted C₁-C₁₀Alkyl, radicals of the structure (VIII)

Wherein o and p are independently selected from integers of 1 to 20, wherein o and p may be the same or differentAn integer, X3 is i) N, S or O, or ii) an aryl or heteroaryl group, wherein [ C (R)_a)₂]_OAnd [ C (R)_a)₂]_pIs present in the meta position to the aryl or the heteroaryl group,

each R_AIndependently of one another, from H or optionally substituted C₁-C₄Alkyl or optionally substituted C₁-C₄An acyl group;

comprising reacting a compound of formula II

Wherein R, R1 and Hal are as defined above, and X2 is a protecting group which may be the same or different from X1 above, a step of reaction with a deprotecting agent, thereby reacting X of the compound of formula II₂Group deprotection;

subsequently, reacting the deprotected compound of formula II with a compound of formula III in the presence of a coupling agent and a base to obtain a compound of formula I

Wherein the substituents Hal, R₁、X₁And R is as defined above and L is a linking group as defined above, R₃Selected from Hal (especially Cl and Br) or OH.

The present invention now allows to modify independently and differently the two OH groups at the 5' position of the benzindole of the two subunits of a bifunctional CBI based prodrug. Cleavage of at least one of the two OH groups is necessary to activate and convert the one subunit into the active drug.

ADCs which can be prepared using the invention, for example, consist of an antibody moiety and a compound of the formula I according to the invention or a deprotected compound, in which X₁Is H or X₁The residue being deprotected, e.g. when X₁Deprotected X when it is tetraacetyl-beta-D-galactoside₁Is beta-D-galactoside.

The linked antibody can be first passed through a low pH in lysosomesThe pH labile group is cleaved at value, and then a first rearrangement occurs to a toxic CBI unit. In a second step, rearrangement of the second toxic CBI unit may be by X₁Enzymatic cleavage of the unit triggers, for example, the galactose unit based on the activity of β -galactosidase in lysosomes and other cellular components such as the endoplasmic reticulum, thereby causing cytotoxicity. Two-step activation, i.e., a first toxicity phase followed by a second toxicity phase, is advantageous in providing better or longer efficacy or with fewer or fewer side effects.

The compounds of formula I allow for the attachment of antibodies on only one phenolic hydroxyl group or on both hydroxyl groups. For example, if both OH groups are conjugated to an antibody, the invention allows for the conjugation of different antibodies on each side. This would have the advantage that two different tumor specific epitopes could be used, which would further improve the specificity of ADC treatment.

The method according to the invention is shown in scheme 1, which outlines the corresponding steps. That is, by reacting compound 11 with compound 12, compound (13) of formula IV, wherein X is obtained₁Is a protected galactoside, i.e. protected by an acetyl group, X₄Is Boc, R is H and R₁Is H and Hal is Cl, thus giving a compound having two protecting groups X₁And X₄Compound 13 of structure III. Reaction of Compound 13 with Compound 14, e.g., where Compound 14 is of Structure VII, wherein R₅And R₆Is Cl, Z and Z' are C ═ O and Y is propyl.

The compound 15 obtained is an example of formula III, wherein R and R₁Is H, Hal is Cl, and L, Z and Z' are C ═ O and Y is (CH)₂)₃，R₃Is OH, X₁Is tetraacetyl-beta-D-galactoside.

Then reacting compound 15 corresponding to the structure of formula III with compound 11 corresponding to structure II, wherein R and R₁＝H，X₂Boc and Hal ═ Cl, first by CH₂Cl₂BF of₃OEt₂Deprotection of 11 and reaction of the deprotected compound 11 with compound 15 in the presence of a base and a coupling agent (here DIPEA and PyBroP) gives the compound of formula IWherein X is₁Is tetraacetyl-beta-D-galactoside, R and R₁For H, Hal is Cl and L is Z, Z' is C ═ O, Y is (CH)₂)₃。

In particular, the present inventors recognized that compound 15 can be selectively reacted with compound 11 to obtain compound 16 in high yield.

In one embodiment of the present invention, X₁And X₂Independently of one another, from the group consisting of tert-butyloxycarbonyl, benzyloxycarbonyl, tosyl, nitrophenyl (nosyl), trimethylsilyl, dimethyl tert-butylsilyl, carbohydrate units, for example furanose, pyranose, protected mono-, di-or trisaccharides, including galactosides (such as. beta. -D-galactosides),. beta. -D-glucuronic acid,. beta. -D-glucoside,. alpha. -D-mannosides, fucose, carbamate-containing moieties, acetal-containing moieties or moieties which can be cleaved oxidatively to ether-containing moieties.

As used herein, the term "antibody" refers to naturally occurring or recombinant antibodies, as well as to antibody fragments. In one embodiment of the invention, the antibody is a humanized antibody or antibody fragment. Suitable antibodies and antibody fragments and methods for their production are well known to the skilled person. If desired, the antibody or antibody fragment is modified to allow binding and cleavage by/at the benzindolyl OH group. Furthermore, the antibody or antibody fragment may comprise a suitable linker region that allows binding and cleavage via/at the benzindole group. Examples thereof are known in the art, e.g. WO 2017/072295 a 1.

The term "antibody compound conjugate" refers to a conjugate of an antibody and a compound according to the invention. The compound may be a prodrug or drug. Thus, one embodiment of the antibody compound conjugate according to the invention is an Antibody Drug Conjugate (ADC).

The term "substituted" with respect to alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, allylsulfonyl, arylsulfonyl, alkoxy, and acyl groups described herein, in particular, means that the group is substituted with one or more substituents selected from the group consisting of: OH, ═ O, ═ S, ═ NR^h、＝N-OR^h、S^h、NH₂、NO_2、NO、N₃、CF₃、CN、OCN、SCN、NCO、NCS、C(O)NH₂C (O) H, C (O) OH, halogen, R^h、SR^h、S(O)R^h、S(O)OR^h、S(O)₂R^h、S(O)₂OR^h、OS(O)R^h、OS(O)OR^h、OS(O)₂R^h、OS(O)₂OR^h、OP(O)(OR^h)(ORⁱ)、P(O)(OR^h)(ORⁱ)、OR^h、NHRⁱ、N(R^h)Rⁱ、⁺N(R^h)(Rⁱ)R^j、Si(R^h)(Rⁱ)R^j、Si(R^h)(Rⁱ)(R^j)、C(O)R^h、C(O)OR^h、C(O)N(Rⁱ)R^h、OC(O)R^h、OC(O)OR^h、OC(O)N(R^h)Rⁱ、N(Rⁱ)C(O)R^h、N(Rⁱ)C(O)OR^h、N(Rⁱ)C(O)N(R^j)R^hAnd thio derivatives of these substituents or protonated or deprotonated forms of these substituents, where R is^h、RⁱAnd R^jIndependently of one another, selected from H and optionally substituted C_1-15Alkyl radical, C_1-15Heteroalkyl group, C_3-15Cycloalkyl radical, C_3-15hHeterocycloalkyl radical, C_4-15Aryl or C_4-15Heteroaryl or a combination thereof, wherein R is^h、RⁱAnd R^jTwo or more of which are optionally linked to each other, thereby forming a cycloalkyl, allyl, or heterocyclic ring.

The term "alkyl" as used herein, unless otherwise specified, refers to a straight or branched chain saturated or unsaturated hydrocarbon, preferably an alkyl group containing 1 to 12, e.g. 1 to 10, carbon atoms, i.e. 1,2, 3,4,5, 6, 7, 8, 9, 10, 11 or 12, preferably 1 to 8, e.g. 1-6 or 1-4 carbon atoms. Examples of alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, isopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, vinyl, alkyl, 1-butenyl, 2-butenyl, isobutenyl, pentenyl and the like.

The term "aryl" or "aromatic ring" refers to a single radical of an aromatic cyclic hydrocarbon. Preferably, the aryl group contains 3 to 14 (e.g. 5 to 10, such as 5, 6 or 10) carbon atoms, more preferably 6 to 10 carbon atoms. These may be arranged in one ring, for example, phenyl, or two or more fused rings (e.g., naphthyl). Preferably, aryl means a monocyclic ring containing 6 carbon atoms or an aromatic bicyclic ring system containing 10 carbon atoms. In some embodiments, an aryl group is unsubstituted. In some embodiments, aryl is substituted.

As used herein, the term "cycloalkyl" refers to a saturated or unsaturated non-aromatic cycloalkyl group containing 1,2, or more rings. Examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclopentenyl, cyclopentadienyl, cyclohexenyl and the like.

The term "heteroalkyl," as used herein, refers to a straight or branched chain saturated or unsaturated hydrocarbon in which at least one carbon atom is replaced with a heteroatom. The heteroatom is preferably selected from S, N, O and P.

The term "heteroaryl" refers to an aromatic mono-radical consisting of one or more fused aromatic ring systems. Wherein at least one carbon atom is substituted with a heteroatom. Suitable heteroatoms include O, N, S or P.

As used herein, the term "acyl" refers to a compound having the general formula R_ac-CH ═ O-functional groups, where R is_acRefers to an optionally substituted hydrocarbon radical, in particular having C₁-C₈A hydrocarbon chain of carbon atoms.

The term "alkylsulfonyl" or "arylsulfonyl" refers to a compound containing SO₂Alkyl or aryl radicals of the residue.

As used herein and throughout the specification, the term "halogen" or "halo" or "Hal" refers to fluorine, chlorine, bromine or iodine.

The protecting group may have or be a functional group. X₁The functional group of (a) may be a cleavable substrate, which, as used herein, refers to a structure that is cleavable under appropriate conditions, i.e., as identified below by enzymatic digestion or other physical or chemical cleavage. That is, in the substituentX₁In the case of functional groups in the form of substrates, cleavage of the substrate can take place intracellularly, in specific compartments, such as lysosomes or other cellular compartments which convert the prodrug to the active drug, respectively. Functional groups include carbohydrate units such as furanose and pyranose or fucose. Further, the functional group is a disaccharide or a trisaccharide. In one embodiment of the invention, the functional group is a galactoside cleavable by galactosidase.

In one aspect of the invention, the substituent Hal is Cl (chlorine) and/or R₁Is H and/or wherein each R is H.

In another embodiment of the invention, the protecting group X₂Is tert-butoxycarbonyl, and X₁Is tetraacetyl-beta-D-galactoside. In addition, in one embodiment of the present invention, the protecting group X₂Is tert-butyloxycarbonyl.

Protecting group X as defined herein₁、X₂And X₄May be chosen, independently of one another, from functional group-protected mono-, di-or tri-or oligosaccharides, in particular hexoses, pentoses or heptoses, which optionally represent deoxy derivatives or amino derivatives thereof. These substituents may be further substituted with the following substituents: halogen, C_1-8Alkyl radical, C_1-8Acyl radical, C_1-8Heteroalkyl group, C_3-7Cycloalkyl radical, C_3-7Heterocycloalkyl radical, C_4-12Aryl or C_4-12Heteroaryl, amino, or amido. Of course, other suitable substituents are also possible, such as labile substituents selected from hemiacetals and acetals, benzyl and substituted benzyl.

In another embodiment, the process is one wherein the base present for reacting the compound of formula II with the compound of formula III is selected from Diisopropylethylamine (DIPEA), triethylamine or pyridine.

Of course, other suitable bases may be used in accordance with the present invention, and the skilled person is familiar with suitable bases.

Further, the coupling agent may be selected from known coupling agents including phosphonium (phosphonium) reagents. Suitable phosphorus reagents include compounds known as PyCloP, PyBroP, PyBoP, PyAoP.

In another embodiment, the process of the present invention, the L moiety has the general formula VI, wherein n is an integer from 1 to 10. In one embodiment, n is an integer from 1 to 5, such as 1,2, 3,4 and 5, particularly 3.

In another embodiment, the invention relates to a process according to the invention, wherein the compound of formula III is obtained by reacting a compound of formula IV with a compound of formula VII,

wherein X₁、R、R₁And Hal is as defined above, X₄Is as in X₁A protecting group as defined, and X₁And X₄

Compounds of the general formula VII are, different from each other:

VII R₅–L–R₆

wherein L has the general structure Z-Y-Z'

Wherein Z, Y and Z' are as defined above, R₅And R₆Independently of one another, from halogen (such as Cl or Br) or OH groups,

whereby in a first step a compound of formula IV is reacted with a deprotecting agent whereby the compound is at X₄Radical elimination

The protection is carried out, and then,

reacting the deprotected compound of formula iv with a compound of formula VII in the presence of a base to give a compound of formula iii.

As discussed above with respect to scheme 1, compounds according to formula IV comprise a protecting group X₄Deprotected by known methods, e.g. using lewis acids, e.g. in Boc form.

That is, deprotection of a compound containing a protecting group can be achieved by using a lewis acid or a bronsted acid. Suitable acids are well known to the skilled person. Alternatively, a protecting group such as carboxybenzyl (cbz-yl) may be used with H in the presence of a catalyst (e.g., a Pd-containing catalyst)₂And (4) deprotection.

The deprotected structure IV is then allowed to react with a compound of formula VII.

In formula VII, Z and Z 'and Y are as defined above, and the structure Z-Y-Z' is L as defined for the formula structure VI.

R₅And R₆Is a leaving group such as a halogen including Cl and Br or a hydroxyl group as part of a carboxyl group.

The base may be a base as defined above, for example Diisopropylamine (DIPEA), triethylamine or pyridine. The skilled person is familiar with suitable bases for this reaction.

In another aspect, the present invention relates to compounds of formula I obtainable by a process according to the invention.

The compounds according to the invention are characterized in that one of the benzindole groups of the bifunctional compound of the general formula I has a free hydroxyl group, while the corresponding substituent on the second part of the benzindole group is protected by a protecting group.

Compounds of formula I according to the invention include those wherein X₁Compounds which are protected or unprotected per se, for example in the case of mono-or di-or tri-saccharides or oligosaccharides, the saccharides are protected or unprotected. For example, in the case of the protection of the base tetraacetyl- β -D-galactoside, there may be no tetraacetyl substituent present, and thus, X₁Thus being free beta-D-galactoside.

The compounds of formula I as described above are suitable for use in the preparation of, for example, antibody compound conjugates, wherein at least one functional group is present which typically comprises an antibody or binding moiety. Binding moieties as defined herein include antibodies or antibody fragments which allow specific binding to a binding partner. In general, the binding moiety may comprise any ligand that allows binding to a binding partner to generate a binding pair, including binding pairs such as ligand receptors, to a cancer specific epitope and to a senescent cell specific epitope.

Furthermore, the protecting group may be a functional group in the form of a substrate, which may be released upon enzymatic digestion, e.g. proteolytic, oxidative or reductive cleavage by enzymes including plasmin, cathepsin B, β -glucuronidase, galactosidase, mannosidase, glucosidase, neuraminidase, glycosidase, maltase, fructosidase, glycosylase, prostate specific antigen, urokinase-type plasminogen activator (u-PA), metalloprotease, cytochrome P450 or enzymes used in other enzyme product therapies (e.g. ADEPT).

In another aspect, the present invention relates to a method for the preparation of an antibody drug conjugate consisting of an antibody moiety and a compound according to formula I, in particular as defined herein, comprising the steps of: the antibody moiety is coupled to the compound of formula I via a free OH group at the 5-position of the benzindolyl of formula I.

The process comprises using as starting material a compound of formula I wherein in one of the two moieties there is a free OH group at the 5-position of the benzindolyl of formula I, while the other OH group at the 5-position of the second benzindolyl of the second moiety is protected by a protecting group, e.g. a functional group, which may itself be protected or unprotected.

In addition, the invention relates to antibody compound conjugates obtainable by the method according to the invention. In one aspect, the antibody compound conjugate is an Antibody Drug Conjugate (ADC).

In another aspect, the invention relates to a process for the preparation of an ADC consisting of two identical or two different antibody moieties and a compound of formula I, wherein X₁Absent or present, the method comprising the steps of: providing an antibody compound conjugate according to the invention, optionally with a deprotection agent as described herein for X₁Deprotection of the group and via a deprotected OH group in position 5 of the benzindole group of formula I, or if X₁Presence of X by deprotection₁Protecting groups, coupling a second antibody moiety to an antibody drug conjugate of the invention. For example, at X₁In the case of galactosides, the second antibody moiety is bound by the deprotected galactoside.

In one aspect, the antibody compound conjugate according to the invention obtainable by the method of the invention comprises two different antibody moieties.

In another aspect, the invention relates to a pharmaceutical composition containing said compound comprising at least one compound according to the invention.

In some embodiments, the pharmaceutical composition for use as disclosed herein further comprises at least one pharmaceutically acceptable carrier. In some embodiments, a compound according to the present invention, or a pharmaceutically acceptable salt, solvate or hydrate thereof, may be comprised in a pharmaceutically acceptable carrier.

As used herein and throughout the specification, the terms "carrier" and "excipient" are used interchangeably herein. Pharmaceutically acceptable carriers or excipients include diluents (fillers, bulking agents, e.g. lactose, microcrystalline cellulose), disintegrants (e.g. sodium starch glycolate, croscarmellose sodium), binders (e.g. PVP, HPMC), lubricants (e.g. magnesium stearate), glidants (e.g. colloidal SiO)₂) Solvents/co-solvents (e.g. aqueous vehicles, propylene glycol, glycerol), buffers (e.g. citrate, gluconate, lactate), preservatives (e.g. sodium benzoate, parabens (Me, Pr and Bu), BKC), antioxidants (e.g. BHT, BHA, ascorbic acid), humectants (e.g. polysorbates, sorbitan esters), antifoaming agents (e.g. simethicone), thickeners (e.g. methylcellulose or hydroxyethylcellulose), sweeteners (e.g. sorbitol, saccharin, aspartame, acesulfame), flavors (e.g. mint, lemon oil, cream sugar, etc.), humectants (e.g. propylene, ethylene glycol, glycerol, sorbitol). One skilled in the art will be readily able to select an appropriate pharmaceutically acceptable carrier or excipient depending, for example, on the formulation of the pharmaceutical composition and the route of administration.

A non-exhaustive list of exemplary pharmaceutically acceptable carriers or excipients includes (biodegradable) liposomes; microspheres made of biodegradable polymers poly (D, L) -lactic-glycolic acid (PLGA), albumin microspheres; synthetic polymers (soluble); nanofibers, protein-DNA complexes; a protein conjugate; red blood cells or virions. Various carrier-based dosage forms include Solid Lipid Nanoparticles (SLNs), polymeric nanoparticles, ceramic nanoparticles, hydrogel nanoparticles, co-polymerized peptide nanoparticles, nanocrystals and nanosuspensions, nanocrystals, nanotubes and nanowires, functionalized nanocarriers, nanospheres, nanocapsules, liposomes, lipid emulsions, lipid microtubules/microbottes, lipid microbubbles, lipid spheres, lipid multimers, reverse lipid micelles, dendrimers, ethosomes, multi-composite ultra-thin capsules, water bodies, pharmaceutical objects, colloids, vesicles, disks, precursor vesicles, microspheres, microemulsions, and polymeric micelles. Other suitable pharmaceutically acceptable excipients are described, inter alia, in Remington's Pharmaceutical Sciences, 15 th edition, Mack Publishing Co., New Jersey (1991) and Bauer et al, Pharmaceutical technology (Pharmazeutische technology), 5 th edition, Govi-VerlagFrankfurt (1997).

The pharmaceutical compositions of the present invention are generally designed for a particular route and method of administration, a particular dosage and frequency of administration, a particular treatment for a particular disease, and a range of bioavailability and persistence. The materials of the composition are preferably formulated at concentrations that are acceptable for the site of administration.

Formulations and compositions may therefore be designed according to the present invention for delivery by any suitable route of administration. In the context of the present invention, routes of administration include:

topical routes (e.g., epidermal, inhaled, nasal, ocular, otic/otic, vaginal, mucosal) and aerosols;

enteral route (e.g. oral, gastrointestinal, sublingual, sublabial, buccal, rectal); and

parenteral routes (e.g., intravenous, intra-arterial, intraosseous, intramuscular, intracerebral, intracerebroventricular, epidural, intrathecal, subcutaneous, intraperitoneal, extraamniotic, intraarticular, intracardiac, intradermal, intralesional, intrauterine, intravesical, intravitreal, transdermal, intranasal, intrasynovial, intraluminal).

In some embodiments, administration may be parenteral, in particular intravenous or intramuscular.

In some embodiments, a pharmaceutical composition as disclosed herein is administered to a subject in need thereof in an amount effective to treat cancer. The subject is preferably a mammal.

As used herein and throughout the specification, the term "subject" refers to eukaryotes, such as animals, including warm-blooded mammals, such as humans and primates; (ii) poultry; domestic or farm animals, such as cats, dogs, sheep, goats, cattle, horse pigs; a pig; laboratory animals such as mice, rats and guinea pigs; fish; a reptile; zoos and wild animals, etc. The subject is preferably a mammal, more preferably a human.

As used herein and throughout the specification, the term "effective amount" in the context of a composition or dosage form for administration to a subject refers to an amount of the composition or dosage form sufficient to provide a benefit in the treatment of cancer, delay or minimize symptoms associated with cancer, or cure or ameliorate cancer. In particular, a therapeutically effective amount refers to an amount sufficient to provide a therapeutic benefit in vivo. When used in conjunction with an amount of a compound of the present invention, the term preferably includes a non-toxic amount that improves overall treatment, reduces or avoids symptoms or causes of disease, or enhances the therapeutic efficacy of or synergizes with another therapeutic agent.

Of course, the effective amount will depend upon the particular subject being treated; the severity of the condition, disease or disorder; parameters of individual patients including age, physical condition, size and weight; the duration of the treatment; the nature of the concurrent therapy (if any); characteristic of the route of administration and similar factors including knowledge and expertise of the medical practitioner. These factors are well known to those of ordinary skill in the art and can be addressed by only routine experimentation. It is generally preferred to use the maximum dose, i.e., the highest safe dose according to sound medical judgment. However, one of ordinary skill in the art will appreciate that a patient may adhere to a lower dose or tolerable dose for medical reasons, psychological reasons, or virtually any other reason.

In another aspect, the invention relates to the use of a compound according to the invention for the treatment of a condition or disease associated with aging.

As used herein, a senescence-associated disorder or disease includes a disorder or disease associated with or caused by cellular senescence, including age-associated diseases and disorders. The senescence-associated disease or disorder may also be referred to as a senescent cell-associated disease or disorder. One prominent feature of aging is the progressive loss of function or degeneration at the molecular, cellular, tissue and body level. Age-related degeneration causes well-recognized pathological conditions such as sarcopenia, atherosclerosis and heart failure, osteoporosis, pulmonary insufficiency, renal failure, neurodegeneration (including macular degeneration, alzheimer's disease, and parkinson's disease), and the like.

Aging-related diseases and disorders include, but are not limited to, cardiovascular diseases and disorders, inflammatory diseases and disorders, autoimmune diseases and disorders, pulmonary diseases and disorders, ocular diseases and disorders, metabolic diseases and disorders, neurological diseases and disorders (e.g., neurodegenerative diseases and disorders); age-related diseases and disorders due to aging; a skin condition; age-related diseases; skin diseases and disorders; and diseases and conditions associated with transplantation.

Preferably, the subject is a mammal, preferably a human.

In a preferred embodiment of the invention, the senescence-associated disease or disorder is a proliferative disorder, such as cancer or leukemia, including lymphoma. In another preferred embodiment, the senescence-associated disease or disorder is cardiovascular disease. In another embodiment of the invention, the disease or disorder associated with aging is an inflammatory or autoimmune disease or disorder.

In another embodiment, the senescence-associated disease or disorder is related to a neurological disease or disorder. Further age-related diseases or disorders include ophthalmic diseases and disorders as well as metabolic diseases and pulmonary diseases or disorders.

Other age-related diseases or conditions refer to age-related conditions as well as skin diseases or conditions and life-span and age-related diseases or conditions. Furthermore, the present application, i.e. the use of a compound of the invention, wherein X₁By galactoside, for example, is meant a disease associated with or associated with increased beta-galactosidase activityOr a condition.

Furthermore, the present invention relates to the use of the compounds according to the invention for the treatment of tumors, in particular in mammals, and in particular possibly in ADEPT therapy.

Furthermore, the present invention relates to the use of compounds of formula I for the preparation of antibody drug conjugates.

The present invention will be further described by way of examples, but is not limited thereto.

Examples

Experimental procedure

General procedure

Unless otherwise stated, experiments were performed in air. Reagents were obtained from commercial sources and used without purification. Dried by drying in a vacuum oven (Vacuterm 6025 from Heraeus Instruments, Heraeus Instruments)

Adding molecular sieve into the bottle purged with argon to obtain anhydrous CH₂Cl₂(analytical grade, Fischer Scientific) and THF (Analr NORMAPUR, VWR). DMF (peptide synthesis grade, fisher technologies c) is used throughout. NMR spectra were recorded on Varian Mercury-300, Unity-300, Inova-500 and Inova-600 spectrometers and Bruker's AMX-300 spectrometer. Chemical shifts are reported in parts per million (ppm) from high to low using the residual solvent peak as an internal reference (DMSO ═ 2.50 ppm).

All of¹The H resonances are reported to the nearest 0.01 ppm.¹The diversity of the H signal is expressed as: s is a single multiplet; d is doublet; t is a triplet; q is quartet; sept ═ heptad; m is multiplet; br is broad peak; app ═ significant peak; or a combination thereof. The coupling constant (J) is expressed in Hz and is accurate to 0.1 Hz. Where appropriate, the value of the coupling constant is calculated using the average value from the signal showing the multiplicity of peaks.¹³C NMR spectra were recorded on the same spectrometer with the central resonance of the solvent peak as an internal reference (DMSO 39.52ppm),¹³the C resonance is reported to the nearest 0.01 ppm. DEPT, COSY, HSQC and HMBThe C experiment was used to aid in structure determination and spectrogram identification. The fully characterized compound was chromatographically homogeneous. Flash column chromatography was performed on an automated system (Isolera One from Biotage) using a Biotage SNAP flash column KP-Sil (silica gel)

53 μm, 96.95% between 30-90 μm) or interchem PF-15SIHP (high performance spherical silica, 15 μm) as stationary phase. Silica gel GF UV 25420X 20cm 2000 micron plates (Anilel technologies-Analtech) or RP-18W/UV₂₅₄Preparative TLC was performed on 5X 20cm 250 micron plates (Macherey-Nagel, Md.) and small amounts of (<10mg of crude material) in analytical TLC silica gel 60F₂₅₄Purification on plate (German Merck). TLC was visually observed using short and long wave uv light in combination with standard laboratory stains (acidic potassium permanganate, acidic ammonium molybdate and ninhydrin). ESI-MS and ESI-HRMS spectra were recorded on an Apex IV mass spectrometer from Bruker Daltronik. EI-MS and EI-HRMS spectra were recorded on a MAT 95 mass spectrometer from Finnigan. Melting points (Mp) were determined using an EZ-Melt automated melting point apparatus from Stanford Research Systems, uncorrected. The infrared spectra were recorded on a FT/IR-4100 spectrometer from Jasco. All substances were applied neat on the ATR unit. The UV spectrum was recorded on a V-630 spectrometer from Jasco. Optical rotations were measured on a JASCO P-2000 polarimeter. Measurements were performed using a sodium lamp (λ 589nm, D-line); [ alpha ] to]Value of

Degree cm²g^-1As indicated, the concentration (c) is in g/per 100 ml. Preparative HPLC was performed on a Jasco HPLC system with UV and DAD detectors using Kromasil 100C 18 (particle size 7.5 μm, 250 x 200mm, meihshi GmbH-dr. maisch GmbH) analytical HPLC with Kromasil 100C 18(5.0 μm particle size, 250 x 4mm, meihshi GmbH) or Chiralpak IA (5 μm particle size, 250 x 4.6mm, dessel-daicilion corporation) chromatography columns.

Unless otherwise stated, hydrogenation was carried out on an H-Cube system (Pd/C10 wt.% loading) of TN Nanotechnology (thales nano Nanotechnology) in a perhydro mode at room temperature at a flow rate of 1.0 mL/min.

(S) -1- (chloromethyl) -5-hydroxy-1, 2-dihydro-3H-benzo [ e ] indole-3-carboxylic acid tert-butyl ester (11)

To an argon-filled flask charged with benzyl ether of CBI11 (200mg, 0.472mmol) and Pd/C (10 wt.% loading, 100mg, 0.940mmol) was added dry THF (20 mL). The argon was carefully replaced with hydrogen using a balloon and the reaction mixture was heated to 40 ℃ for 10 h. The mixture was filtered through celite, and the residue was washed with EtOAc (3 × 50 mL). The combined filtrates were concentrated under reduced pressure and purified by flash column Chromatography (CH)₂Cl₂EtOAc, 94: 6) purification gave the title compound (113mg, 0.340mmol) as a white solid in 72% yield.

R_f0.45(CH₂Cl₂EtOAc, 92: 8) the dechlorinated product is 0.39

(2R, 3S, 4S, 5R, 6S) -2- (acetoxymethyl) -6- (((((S) -3- (tert-butoxycarbonyl) -1- (chloromethyl) -2, 3-dihydro-1H-benzo [ e ] indol-5-yl) oxy) tetrahydro-2H-pyran-3, 4, 5-triacetic acid triester (13)

To a solution of naphthol 11(138mg, 0.413mmol), tetraacetyl- β -D-galactosyltrichloroacetamido 12(265mg, 0.537mmol) and

molecular sieve flask with dry CH₂Cl₂(21 mL). The mixture was stirred for 30 minutes and dried CH of boron trifluoride diethyl ether adduct (26. mu.L, 0.21mmol) was added at-10 deg.C₂Cl₂(2.0mL) in solution. The reaction mixture was stirred at-10 deg.CFor 3h, and concentrated under reduced pressure. Purification by flash column chromatography (PET/EtOAc, 1: 0 to 1: 1) gave the desired compound (223mg, 0.336mmol) as a white solid in 81% yield.

5- ((S) -1- (chloromethyl) -5- (((((2S, 3R, 4S, 5S, 6R) -3,4, 5-triacetoxy-6- (acetoxymethyl) tetrahydro-2H-pyran-2-yl) oxy) -1, 2-dihydro-3H-benzo [ e ] indol-3-yl) -5-oxopentanoic acid (15)

CBI tetraacetyl-beta-D-galactoside 13(50mg, 0.075mmol) was adsorbed in CH₂Cl₂(3.0mL) and two drops of boron trifluoride diethyl ether adduct are added at 0 deg.C. The reaction mixture was allowed to warm to room temperature and stirred for an additional 2 hours. After completion, the mixture was concentrated under reduced pressure and dissolved in peptide grade DMF (1 mL). The resulting solution was cooled to 0 ℃ and slowly added to a solution of freshly prepared glutaryl dichloride 14(0.19g, 1.1mmol) in peptide grade DMF (1mL) at 0 ℃. After dropwise addition of DIPEA (0.20mL), the reaction mixture was stirred for 30 minutes and concentrated under reduced pressure. Flash column Chromatography (CH)₂Cl₂MeOH, 100: 0 to 96: 4) the title compound (41mg, 0.061mmol) was produced in 80% yield as a light brown solid.

R_f0.74(EtOAc)

Melting point 155 deg.C

¹H-NMR(500MHz,DMSO-d₆):δ8.29(s,1H),7.91(d,J＝8.4Hz,1H),7.88(d,J＝8.4Hz,1H),7.56(app t,J＝7.2Hz,1H),7.41(app t,J＝7.4Hz,1H),5.57(d,J＝6.5Hz,1H),5.45–5.38(m,3H),4.55(dd,J＝7.5,4.5Hz,1H),4.34(app t,J＝9.8Hz,1H),4.26–4.14(m,3H),4.07(dd,J＝11.5,7.8Hz,1H),4.01(dd,J＝10.9,3.0Hz,1H),3.88(dd,J＝11.0,7.4Hz,1H),2.66–2.46(m,2H),2.34(app t,J＝7.4Hz,2H),1.83(m,2H)

¹³C-NMR(126MHz,DMSO-d₆):δ174.39,170.69,170.38,170.12,169.76,169.56,153.04,141.77,129.61,127.74,124.11,122.99,122.03,121.97,117.92,101.43,98.83,70.92,69.83,68.53,67.54,61.84,52.62,47.73,40.66,34.24,32.97,20.59,20.47,20.43,20.43,19.57

HRMS(ESI)m/z C₃₂H₃₅ClNO₁₃[M-H]^-Calculated value 676.1797, found value 676.1797

(2R, 3S, 4S, 5R, 6S) -2- (acetoxymethyl) -6- ((((S) -1- (chloromethyl) -3- (5- ((S) -1- (chloromethyl) -5-hydroxy-1, 2-dihydro-3H-benzo [ e ] indol-3-yl) -5-oxopentanoyl) -2, 3-dihydro-1H-benzo [ e ] indol-5-yl) oxy) tetrahydro-2H-pyran-3, 4, 5-triacetic acid triester (16)

CBI-tetraacetyl-beta-D-galactoside-glutaric acid monoamide 15(12mg, 0.035mmol) was absorbed in CH₂Cl₂(2mL) and 3 drops of boron trifluoride diethyl ether adduct are added at 0 deg.C. The reaction mixture was allowed to warm to room temperature and the deprotection was monitored by TLC. After 2 hours, the reaction mixture was concentrated under reduced pressure and the crude solid was kept under high vacuum for a further 1 hour. Acid 5(20mg, 0.030mmol), molecular sieves were placed under an argon atmosphere

And DMF (0.30mL) was added to the solution. The resulting mixture was cooled to-20 ℃ and PyBroP (16mg, 0.035mmol) and DIPEA (15. mu.L, 0.089mmol) were added sequentially. The reaction mixture was kept at-20 ℃ overnight and heated to 0 ℃ the following day. The reaction was stirred at this temperature for a further 8h and then concentrated under reduced pressure. The crude product was purified by flash column chromatography (PET/EtOAc, 1: 0 to 3: 7) to give 16 as a light brown solid (14mg, 0.016mmol) in 44% yield.

R_f0.51(EtOAc/PET，2：1)

Melting point 155 deg.C

¹H-NMR(600MHz,DMSO-d₆):δ10.31(s,1H),8.33(br s,1H),8.09(d,J＝8.2Hz,1H),8.02(br s,1H),7.94(d,J＝8.5Hz,1H),7.89(d,J＝8.4Hz,1H),7.78(d,J＝8.4Hz,1H),7.56(m,1H),7.49(m,1H),7.42(m,1H),7.32(m,1H),5.56(m,1H),5.43–5.41(m,2H),5.40(m,1H),4.54(dd,J＝7.1,4.8Hz,1H),4.38(app t,J＝10.2Hz,1H),4.33(app t,J＝10.0Hz,1H),4.27–4.21(m,2H),4.20–4.13(m,3H),4.10(dd,J＝11.4,7.7Hz,1H),4.03(dd,J＝11.1,3.1Hz,1H),3.99(dd,J＝11.1,3.0Hz,1H),3.89(dd,J＝11.1,7.4Hz,1H),3.79(dd,J＝10.8,8.3Hz,1H),2.77–2.67(m,2H),2.66–2.57(m,2H),2.18(s,3H),2.08(br s,3H),2.02(s,3H),2.01–1.95(m,2H),1.97(s,3H)

¹³C-NMR(126MHz,DMSO-d₆):δ170.62,170.37,169.94,169.72,169.35,169.16,154.03,152.79,141.81,141.53,129.77,129.41,127.44,126.98,123.82,122.90,122.71,122.42,122.30,121.90,121.78,121.46,117.75,113.56,101.50,99.70,98.78,70.75,69.75,68.48,67.38,61.57,52.58,52.58 47.53,47.53 40.74,40.74,34.39,25.03,20.48,20.34,20.34,20.30,19.15

LRMS(ESI)m/z C₄₅H₄₆Cl₂N₂NaO₁₃[M+Na]⁺Calculated value 915.3, found value 915.3(100), C₄₅H₄₇Cl₂N₂O₁₃[M+H]⁺: 893.3 found value 893.2(24)

HRMS(ESI)m/z C₄₅H₄₆Cl₂N₂NaO₁₃[M+Na]⁺Calculated value 915.2269, found value 915.2263