Nitrogen-containing heterocyclic compound, conjugate thereof, method for preparing same, and use thereof

Abstract

Provided are a nitrogen-containing heterocyclic compound, a conjugate thereof, a method for preparing same, and use thereof. Provided is a ligand-drug conjugate, a tautomer, enantiomer, diastereoisomer or mixture form thereof, or a pharmaceutically acceptable salt or solvate thereof, wherein the ligand-drug conjugate comprises a ligand and a structure represented by formula (I). The nitrogen-containing heterocyclic compound and the conjugate thereof have one or more effects selected from the following group: (1) inhibitory activity against the in-vitro proliferation of tumor cells; (2) good plasma stability; (3) an in-vivo tumor inhibitory effect; (4) resistance against transporter-mediated transport; (5) an in-vivo tumor targeting capability; and (6) good in-vivo safety.

Description

A nitrogen-containing heterocyclic compound, its conjugate, and its preparation method and use

[0001] This application claims priority to Chinese Patent Application No. 2024101791649, filed on February 8, 2024. This application incorporates the entirety of the aforementioned Chinese Patent Application. Technical Field

[0002] The present invention relates to a nitrogen-containing heterocyclic compound, a conjugate thereof, and a preparation method and application thereof. Background Art

[0003] Immunomodulators (such as thalidomide, lenalidomide, pomalidomide, CC-885, CC-90009, etc.) act as "molecular glue" to bind to cereblon (CRBN) through the glutarimide ring structure and promote the activation of CRL4. CRBN E3 ubiquitin ligases mediate the recruitment and ubiquitination of substrate proteins such as GSPT1, IKZF1 / 3, CK1α, MYC, etc. Although these compounds are exciting as new cancer therapies, their use has so far been limited to hematological malignancies such as multiple myeloma and myelodysplastic syndrome (MDS) and is associated with serious adverse events (AEs) in the clinic.

[0004] Antibody-drug conjugates (ADCs) link monoclonal antibodies or antibody fragments to biologically active cytotoxic drugs via a stable chemical linker. They leverage the specificity of antibodies for binding to surface antigens on both normal and tumor cells and the high efficacy of cytotoxic drugs, while avoiding the drawbacks of the former, such as low efficacy, and the latter's excessive toxic side effects. This means that compared to traditional chemotherapy drugs, ADCs can precisely bind to tumor cells while minimizing their effects on normal cells (Mullard A, (2013) Nature Reviews Drug Discovery, 12:329–332; DiJoseph JF, Armellino DC, (2004) Blood, 103:1807-1814), resulting in greater efficacy and a wider therapeutic window.

[0005] By taking advantage of the differences in surface antigen expression between tumor cells and normal cells, protein degraders are constructed into antibody-drug conjugates with antibodies that bind to tumor cell surface antigens. This can not only improve the clinical efficacy and tolerability of protein degraders, but also expand their possible therapeutic range, such as for the treatment of breast cancer, lung cancer, liver cancer, gastric cancer and prostate cancer, thereby breaking through the limitations of small molecule protein degraders and providing patients with more options.

[0006] Therefore, it is necessary to design and synthesize a series of protein degrader conjugates with significant anti-tumor activity for the treatment of tumor-related diseases. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the drawback of the limited variety of existing antibody-drug conjugates, thereby providing a nitrogen-containing heterocyclic compound, a conjugate thereof, and a preparation method and use thereof. The nitrogen-containing heterocyclic compound and the conjugate thereof of the present invention have one or more effects selected from the following group: (1) inhibitory activity on tumor cell proliferation in vitro; (2) plasma stability; (3) in vivo tumor inhibition effect; (4) anti-transporter transport ability; (5) in vivo tumor targeting ability; and (6) good in vivo safety.

[0008] In one aspect, the present invention provides a ligand-drug conjugate, or a tautomer, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt or solvate thereof, wherein the ligand-drug conjugate comprises a ligand and a structure represented by formula (I):

[0009] in,

[0010] R 1 For hydrogen, deuterium, halogen, C 1-6 Alkyl or halogenated C 1-6 alkyl;

[0011] Ring A is: Among them, 1 is connected to V, and 2 is connected to piperidinedione;

[0012] U is -CH2- or -C(O)-;

[0013] R a Each is independently hydrogen, halogen, -OH, -CN, -NH2, nitro, C 1-6 Alkyl, -OC 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl or 4 to 12 membered heterocycloalkyl; the C 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl or 4- to 12-membered heterocycloalkyl are each optionally substituted with one or more substituents selected from halogen, -OH, -CN, -NH2 and oxo;

[0014] k2 is 0, 1, 2, or 3;

[0015] V is -NH- or -O-;

[0016] L is a chemical bond, -C 1-6 Alkylene or -halogenated C 1-6 Alkylene-;

[0017] Ring B is C 6-10 aryl, 5-10 membered heteroaryl, or 4- to 12-membered heterocycloalkyl;

[0018] R 2 are independently hydrogen, deuterium, halogen, nitro, -CN, -OH, -NH2, C 1-6 Alkyl, -OC 1-6 Alkyl, -NHC 1-6 Alkyl, -N(C 1-6 Alkyl)2, C 2-6 Alkenyl, C 2-6 Alkynyl, -CONH2, -COOH, -QC 0-6 Alkylene-C 3-12 Cycloalkyl, -QC 0-6 Alkylene-(4-12 membered heterocycloalkyl), -QC 0-6 Alkylene-C 6-10 Aryl or -QC 0-6 Alkylene-(5-10 membered heteroaryl); the C 1-6 Alkyl, C 0- 6 alkylene, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl, 4-12 membered heterocycloalkyl, C 6-10 Aryl or 5-10 membered heteroarylene is optionally substituted with one or more halogen, -CN, -OH, -NH2, C 1-6 Alkyl, oxo, halo 1-6 Alkyl, -OC 1-6 Alkyl, -NHC 1-6 Alkyl and -N(C 1-6 alkyl)2 substituted;

[0019] Or, any two adjacent R 2 Together with the atoms it is connected to form C 5-8 Cycloalkyl or 5- to 8-membered heterocycloalkyl;

[0020] Q is each independently a chemical bond, -O-, -S-, or -NH-;

[0021] k1 is 0, 1, 2, or 3;

[0022] W is a chemical bond, -O-, -S-, -NR w -、-C 1-6 Alkylene- or -(C1-6 alkylene) m1 -(X) m2 -(C 1-6 alkylene) m3 -(Y) m4 -;

[0023] X and Y are each independently selected from -O-, -S-, -NR w -、-C(O)-、-NR c C(O)-、-C(O)NR w -, -S(O)-, -S(O)2-, -S(O)2NR w -、-NR w S(O)2-, or -OC(O)-; the C 1-6 The alkylene group is optionally substituted with one or more halogens;

[0024] m1, m2, m3 and m4 are each independently 0 or 1; and m2 and m4 are not 0 at the same time, and m1 and m3 are not 0 at the same time;

[0025] R w For hydrogen, C 1-6 Alkyl, C 6-10 Aryl, C 3-12 Cycloalkyl, 5-10 membered heteroaryl or 4 to 12 membered heterocycloalkyl; the C 1-6 Alkyl, C 6-10 Aryl, C 3-12 Cycloalkyl, 5-10 membered heteroaryl or 4 to 12 membered heterocycloalkyl are each optionally substituted by one or more radicals selected from halogen, -CN, -OH, -NH2, C 1-6 Alkyl and halogenated C 1-6 Alkyl substitution;

[0026] or R w Can be used with R 2 and the N atom and C atom to which it is connected together form a 5-12 membered heterocycloalkyl group; the heterocycloalkyl group is optionally substituted by one or more halogen, -CN, -OH, -NH2, C 1-6 Alkyl and halogenated C 1-6 Alkyl substitution;

[0027] R 3 For chemical bonds, C 1-6 Alkylene, C 2-6 Alkenylene, C 2-6 Alkynylidene, C 3-12 Cycloalkylene, 4 to 12 membered heterocycloalkylene, C 6- 10 Arylene or 5-10 membered heteroarylene; the C 1-6 Alkylene, C 2-6Alkenylene, C 2-6 Alkynylidene, C 3-12 Cycloalkylene, 4 to 12 membered heterocycloalkylene, C 6-10 Arylene or 5-10 membered heteroarylene are each optionally substituted by one or more selected from halogen, -OH, -CN, -NH2, -SH, nitro, -OC 1-6 Alkyl, -O(halogenated C 1-6 Alkyl), -NHC 1-6 Alkyl, -N(C 1-6 Alkyl)2, -SC 1-6 Alkyl, C 1-6 Alkyl, halogenated C 1-6 Alkyl, -C 1-6 Alkyl-OH, -C 1-6 Alkyl-OC 1-6 Alkyl, -C 1-6 Alkyl-SH, -C 1-6 Alkyl-SC 1-6 Alkyl, -C 1-6 Alkyl-NH2, -C 1-6 Alkyl-NH(C 1-6 Alkyl), -C 1-6 Alkyl-N(C 1-6 Alkyl)2, -C(O)NH2, -COOH, -C(O)NHC 1-6 Alkyl, -C(O)N(C 1-6 Alkyl)2, -NHC(O)C 1-6 Alkyl, -NHC(O)OC 1-6 Alkyl, -S(O)2C 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-6 cycloalkyl and 4- to 6-membered heterocycloalkyl substitution;

[0028] Z is a chemical bond, -C 0-6 Alkylene-NH-, -C 0-6 Alkylene-N(C 1-6 Alkyl)-, -C 0-6 Alkylene-O- or -C 0-6 Alkylene-S-.

[0029] In some embodiments, R 1 is hydrogen, deuterium or -CH3; preferably, R 1 For H.

[0030] In some embodiments, Ring A is: Preferably, Ring A is: More preferably, Ring A is Among them, 1 is connected to V, 2 is connected to piperidinedione; and k2 is 0 or 1.

[0031] In some embodiments, R a are each independently hydrogen, deuterium, halogen, -OH, -CN, -NH2, nitro, -CH3 or -OCH3; preferably, R a is hydrogen, F, -OH, -NH2 or -CH3; more preferably, R a is hydrogen or F.

[0032] In some embodiments, V is -NH-.

[0033] In some embodiments, V is -O-.

[0034] In some embodiments, L is a chemical bond or -CH2-; preferably, L is -CH2-.

[0035] In some embodiments, Ring B is C 6-10 aryl, 5-10 membered heteroaryl or 5 to 10 membered heterocycloalkyl; preferably, ring B is phenyl or pyridyl; more preferably, ring B is phenyl.

[0036] In some embodiments, k1 is 0, 1 or 2; preferably, k1 is 0 or 1.

[0037] In some embodiments, R 2 are independently hydrogen, halogen, -CN, -OH, C 1-6 Alkyl, -OC 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl or 4-12 membered heterocycloalkyl; the C 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl or 4-12 membered heterocycloalkyl are each optionally substituted with one or more halogen, C 1-6 Alkyl, -OC 1-6 Alkyl and halogenated C 1-6 Alkyl substituted; preferably, R 2 Each is independently hydrogen, F, Cl, Br, -CN, -CH3, -iPr, -tBu, -CF3, -CHF2, -OCH3, -OCF3, -O-CH2-CH2-O-CH3, cyclopropyl, vinyl or ethynyl; more preferably, R 2 Each is independently hydrogen, F, Cl, -CH3 or -CF3.

[0038] In some embodiments, R 2 Each independently -OC6-10 Aryl, -O-CH2-C 6-10 Aryl, -CH2-C 6-10 Aryl, -O-(5-6 membered heteroaryl), -O-CH2-(5-6 membered heteroaryl), -CH2-(5-6 membered heteroaryl), -SC 6-10 Aryl or -S-(5-6 membered heteroaryl); the -CH2-, C 6-10 Aryl or 5-6 membered heteroaryl are each optionally substituted with one or more F, Cl, C 1-6 Alkyl and halogenated C 1-6 Alkyl substitution;

[0039] Preferably, R 2 Each is independently -O-phenyl, -O-CH2-phenyl, -CH2-phenyl, -O-pyridyl, -O-CH2-pyridyl, -CH2-pyridyl, -S-phenyl or -S-pyridyl; the phenyl and pyridyl groups are each optionally substituted with one or more F, Cl, -CH3 and -CF3;

[0040] In some embodiments, W is a chemical bond, -O-, -S-, -NH-, -C 1-3 Alkylene-, -N(C 1-3 Alkyl)-, -(C 1-3 alkylene) m1 -(O) m2 -(C 1-3 alkylene) m3 -(O) m4 -、-(C 1-3 alkylene) m1 -(O) m2 -(C 1-3 alkylene) m3 -(N(C 1-6 alkyl)) m4 -、-(C 1-3 alkylene) m1 -(N(C 1-6 alkyl)) m2 -(C 1-3 alkylene) m3 -(O) m4 -or-(C 1-3 alkylene) m1 -(N(C 1-6 alkyl)) m2 -(C 1-3 alkylene) m3 -(N(C 1-6 alkyl)) m4 -.

[0041] In some embodiments, W and R 2and the N atom and C atom to which it is connected together form a 5-6 membered heterocycloalkyl group; the heterocycloalkyl group is optionally substituted by one or more halogen, -C 1-6 Alkyl and -halogenated C 1-6 Alkyl substitution.

[0042] In some embodiments, R 3 For chemical bonds, C 1-4 Alkylene, C 3-6 Cycloalkylene, 4 to 6 membered heterocycloalkylene, C 6-10 Arylene or 5-6 membered heteroarylene; the C 1-4 Alkylene, C 3-6 Cycloalkylene, 4 to 6 membered heterocycloalkylene, C 6-10 Arylene or 5-6 membered heteroarylene are each optionally substituted by one or more selected from halogen, -OH, -CN, -OC 1-6 Alkyl, -O(halogenated C 1-6 Alkyl), -NHC 1-6 Alkyl, -N(C 1-6 Alkyl)2, C 1-6 Alkyl, halogenated C 1-6 Alkyl, -C 1-6 Alkyl-OC 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-6 cycloalkyl and 4- to 6-membered heterocycloalkyl.

[0043] In some embodiments, R 3 is a chemical bond, phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperazylene, piperidylene, morpholinylene, azetidinylene, azetidinylene, oxetanylene or oxetanylene; the phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperazylene, piperidylene, morpholinylene, azetidinylene, azetidinylene, oxetanylene or oxetanylene are each optionally substituted by one or more halogen, -OH, -CN, -OC 1- 6-alkyl, -O(halogenated C 1-6 Alkyl), C 1-6 Alkyl, halogenated C 1-6 Alkyl or C 3-6 Cycloalkyl substitution.

[0044] In some embodiments, R 3is a chemical bond, phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperazylene, piperidylene, morpholinylene, azetidinylene, azetidinylene, oxetanylene or oxetanylene; the phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperazylene, piperidylene, morpholinylene, azetidinylene, azetidinylene, oxetanylene or oxetanylene are each optionally substituted by one or more selected from F, Cl, -OH, -CN, -OC 1- 6-alkyl, -O(halogenated C 1-6 Alkyl), C 1-6 Alkyl, halogenated C 1-6 Alkyl or C 3-6 Cycloalkyl substitution.

[0045] In some embodiments, R 3 is a chemical bond, a phenylene group, a pyridylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a piperazylene group, a piperidylene group, a morpholinyl group, an azetidinyl group or an azetidinyl group; the phenylene group, the pyridylene group, the cyclobutylene group, the cyclopentylene group, the cyclohexylene group, the piperazylene group, the piperidylene group, a morpholinyl group, an azetidinyl group or an azetidinyl group are each optionally substituted by one or more groups selected from F, Cl, -OH, -CN, -OCH3, -OCF3, -CH3, -iPr, -tBu, -CF3 or -cyclopropyl.

[0046] In some embodiments, Z is a chemical bond, provided that W and R 3 It cannot be a chemical bond at the same time.

[0047] In some embodiments, Z is -NH- or -N(CH3)-; preferably, Z is -NH-.

[0048] In some embodiments, each halogen is independently fluorine, chlorine, bromine, or iodine, preferably fluorine.

[0049] In some embodiments, each C 1-6 Alkyl is independently methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl or sec-butyl, for example methyl.

[0050] In some embodiments, each -OC 1-6 Alkyl is independently -O-methyl, -O-ethyl, -O-n-propyl, -O-isopropyl, -O-n-butyl, -O-tert-butyl, -O-isobutyl or -O-sec-butyl; for example -O-methyl.

[0051] In some embodiments, each C 2-6 Alkenyl is independently ethenyl, propenyl, allyl, butenyl or pentenyl.

[0052] In some embodiments, each C 2-6 Alkynyl is independently ethynyl, propynyl, propargyl, butynyl or pentynyl, for example

[0053] In some embodiments, each C 3-12 Cycloalkyl is independently C 3-8 Cycloalkyl, for example cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl.

[0054] In some embodiments, the cycloalkyl group is a saturated cycloalkyl group.

[0055] In some embodiments, the cycloalkyl group is a partially saturated cycloalkyl group; the number of unsaturated bonds in the partially saturated cycloalkyl group is one or more.

[0056] In some embodiments, each 4- to 12-membered heterocycloalkyl group is independently a 5- to 8-membered heterocycloalkyl group.

[0057] In some embodiments, the heteroatom of each 4- to 12-membered heterocycloalkyl group is independently N, O or S, and the number of heteroatoms is independently 1, 2 or 3; preferably, the heteroatom of each 4- to 12-membered heterocycloalkyl group is independently N or O, and the number of heteroatoms is independently 1 or 2.

[0058] In some embodiments, each 4- to 12-membered heterocycloalkyl group is independently a monocyclic or polycyclic ring, and the polycyclic ring may be a bridged ring, a paracyclic ring or a spirocyclic ring; the polycyclic ring may be a bicyclic ring or a tricyclic ring; preferably, each 4- to 12-membered heterocycloalkyl group is independently a 5- to 6-membered monocyclic heterocycloalkyl group, a 9- to 10-membered bicyclic heterocycloalkyl group or an 11- to 12-membered tricyclic heterocycloalkyl group.

[0059] In some embodiments, each C 1-6 The alkylene group is independently methylene, ethylene, n-propylene, isopropylene, n-butylene, tert-butylene, isobutylene or sec-butylene, preferably methylene.

[0060] In some embodiments, each C 6-10 Aryl is independently phenyl or naphthyl, for example phenyl.

[0061] In some embodiments, the heteroatom of each 5-10 membered heteroaryl is independently N, O or S, and the number of heteroatoms is independently 1, 2 or 3.

[0062] In some embodiments, each 5-10 membered heteroaryl is independently monocyclic or bicyclic, and the bicyclic rings are fused.

[0063] In some embodiments, each 4- to 14-membered heterocycloalkyl group is a 5- to 12-membered heterocycloalkyl group.

[0064] In some embodiments, the heteroatom of each 4- to 14-membered heterocycloalkyl group is N, O, or S, and the number of heteroatoms is 1, 2, or 3; preferably, the heteroatom is N, and the number of heteroatoms is 1 or 2.

[0065] In some embodiments, each 4- to 14-membered heterocycloalkyl group is monocyclic or polycyclic (eg, bicyclic or tricyclic), and the polycyclic rings may be bridged, fused, or spirocyclic.

[0066] In some embodiments, each 4- to 14-membered heterocycloalkyl group contains 0, 1 or 2 unsaturated rings, preferably 1 unsaturated ring and at least one saturated ring; the unsaturated ring is preferably an aromatic ring.

[0067] In some embodiments, when each 4- to 14-membered heterocycloalkyl group contains one unsaturated ring and at least one saturated ring, the heteroatom is located in the saturated ring.

[0068] In some embodiments, each 4- to 14-membered heterocycloalkyl group contains 0, 1, or 2 unsaturated bonds.

[0069] In some embodiments, each 4- to 14-membered heterocycloalkyl group is a monocyclic heterocycloalkyl group, a bicyclic heterocycloalkyl group, or a tricyclic heterocycloalkyl group; preferably, a 5- to 6-membered monocyclic heterocycloalkyl group, a 9- to 10-membered bicyclic heterocycloalkyl group, or an 11- to 14-membered tricyclic heterocycloalkyl group; for example

[0070] In some embodiments, the heterocycloalkyl group is a saturated heterocycloalkyl group.

[0071] In some embodiments, the heterocycloalkyl group is a partially saturated heterocycloalkyl group; the number of unsaturated bonds in the partially saturated heterocycloalkyl group is one or more.

[0072] In some embodiments, each C 0-6 The alkylene group is independently a link, a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, a tert-butylene group, an isobutylene group or a sec-butylene group, preferably a link, a methylene group or an ethylene group.

[0073] In some embodiments, the structure represented by formula (I) is the structure represented by formula (Ia):

[0074] in,

[0075] R 1 、R a 、R 2 、R 3 , V, L, W, Z, Ring B, k1 and k2 are as defined in any one of the formula (I) of the present invention.

[0076] In some embodiments, the structures represented by Formula (I) and Formula (Ia) are represented by Formula (Ib):

[0077] in,

[0078] R a 、R 2 、R 3 , W, Z, k1 and k2 are as defined in any one of formula (I) of the present invention.

[0079] In some embodiments, the structure represented by Formula (I), Formula (Ia), or Formula (Ib) is the structure represented by Formula (Ib-1):

[0080] in,

[0081] R a 、R 2 , W, k1 and k2 are as defined in any one of formula (I) of the present invention.

[0082] In some embodiments, the structures represented by formula (I), formula (Ia), formula (Ib), and formula (Ib-1): wherein,

[0083] R 2 Each is independently hydrogen, F, Cl, Br, -CN, -CH3, -iPr, -tBu, -CF3, -CHF2, -OCH3, -OCF3, -O-CH2-CH2-O-CH3, cyclopropyl, vinyl or ethynyl; preferably, R 2 Each is independently hydrogen, F, Cl, -tBu, -O-CH2-CH2-O-CH3;

[0084] Or, any two adjacent R 2 Together with the atoms it is connected to form C 5-8 Cycloalkyl, 5 to 8 membered heterocycloalkyl; preferably, two adjacent R 2 Together with the atoms it is connected to, it forms The C 5-8 Cycloalkyl, 5- to 8-membered heterocycloalkyl or Each is optionally substituted by one or more halogen, -CN, -OH, -NH2, C 1-6 Alkyl, oxo, halo 1-6 Alkyl, -OC 1-6 Alkyl, -NHC 1-6 Alkyl and -N(C 1-6 alkyl)2 substituted;

[0085] Or, R 2Each is independently -O-phenyl, -O-CH2-phenyl, -CH2-phenyl, -O-pyridyl, -O-CH2-pyridyl, -CH2-pyridyl, -S-phenyl or -S-pyridyl; preferably, R 2 Each is independently -O-phenyl, -O-CH2-phenyl, -CH2-phenyl, -O-pyridyl, -O-CH2-pyridyl, -S-phenyl; the phenyl and pyridyl groups are each optionally substituted with one or more F, Cl, -CH3 and -CF3;

[0086] W is -NH-, -N(C 1-3 alkyl)-, -CH2CH2-O-CH2CH2-NH-, -CH2CH2-O-CH2CH2-N(CH3)-, -CH2-O-CH2CH2-N(CH3)-, -CH2-O-CH2CH2CH2-N(CH3)-, -O-CH2CH2-NH- or -O-CH2CH2-N(CH3)-; preferably, W is -NH-, -N(C 1-3 alkyl)-, -CH2CH2-O-CH2CH2-N(CH3)-, -O-CH2CH2-N(CH3)-, or -CH2-O-CH2CH2CH2-N(CH3)-;

[0087] Or, W and R 2 Together with its connected N and C atoms, it forms Side a is connected to ring B in a ring-like manner.

[0088] In some embodiments, the structures represented by Formula (I), Formula (Ia), Formula (Ib), and Formula (Ib-1): wherein,

[0089] R 2 Each is independently hydrogen, F, Cl, -CH3, -O-phenyl, -S-phenyl;

[0090] W is -NH-, -CH2CH2-O-CH2CH2-N(CH3)- or -O-CH2CH2-N(CH3)-;

[0091] Or, W and R 2 Together with its connected N and C atoms, it forms Side a is connected to ring B in a ring-like manner.

[0092] In some embodiments, the structure represented by Formula (I), Formula (Ia), Formula (Ib), or Formula (Ib-1) is a compound represented by (Ib-1a), (Ib-1b), (Ib-1c), (Ib-1d), or (Ib-1e):

[0093] Ra 、R 2 and W are as defined in any one of formula (I) of the present invention.

[0094] In some embodiments, the structure represented by Formula (I), Formula (Ia), or Formula (Ib) is the structure represented by Formula (Ib-2):

[0095] in,

[0096] R a 、R 2 、R 3 , W, k1 and k2 are as defined in any one of formula (I) of the present invention.

[0097] In some embodiments, the structures represented by formula (I), formula (Ia), formula (Ib), and formula (Ib-2): wherein,

[0098] R 2 Each independently represents hydrogen, F, Cl, Br, -CN, -CH3, -CF3, -CHF2, -OCH3 or -OCF3; preferably, R 2 are each independently hydrogen, F or Cl;

[0099] W is a chemical bond, -O-, -S-, -NR w -, -CH2-, -CH2CH2-O-, -O-CH2CH2-, -CH2-O-CH2-, -CH2-O- or -O-CH2-; Preferably, W is a chemical bond, -O-, -S-, -CH2-, -CH2CH2-O-, -O-CH2CH2-, -CH2-O-CH2-, -CH2-O- or -O-CH2-;

[0100] R w is hydrogen or -C 1-6 Alkyl; preferably hydrogen;

[0101] R 3 is phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperidylene, azetidinylene or azetidinylene; preferably, R 3 is phenylene, cyclobutylene, cyclohexylene, piperidinylene or azetidinylene; the phenylene, pyridinylene, cyclobutylene, cyclopentylene, cyclohexylene, piperidinylene, azetidinylene or azetidinylene are each optionally substituted by one or more groups selected from F, Cl, -OH, -CN, -OCH3, -OCF3, -CH3, -iPr, -tBu, -CF3 or -cyclopropyl.

[0102] In some embodiments, the structures represented by formula (I), formula (Ia), formula (Ib), and formula (Ib-2), wherein,

[0103] R 2 are each independently hydrogen, F or Cl;

[0104] W is -S-, -O-CH2- or -CH2-O-;

[0105] R 3 It is a phenylene group.

[0106] In some embodiments, the compounds represented by formula (I), formula (Ia), formula (Ib) and formula (Ib-2):

[0107] in,

[0108] for

[0109] In some embodiments, the structure represented by Formula (I), Formula (Ia), Formula (Ib), or Formula (Ib-2) is a compound represented by (Ib-2a), (Ib-2b), or (Ib-2c):

[0110] in,

[0111] R 2 、R 3 and W are as defined in any one of formula (I) of the present invention.

[0112] In some embodiments, the structure represented by Formula (I), Formula (Ia), or Formula (Ib) is the structure represented by Formula (Ib-3):

[0113] in,

[0114] R 3 for wherein the a end is connected to W; ring D is a 4 to 12 membered heterocycloalkylene; each of the 4 to 12 membered heterocycloalkylene is optionally substituted with one or more selected from halogen, -OH, -CN, -NH2, nitro, -OC 1-6 Alkyl, -O(halogenated C 1-6 Alkyl), C 1-6 Alkyl, halogenated C 1-6 Alkyl substitution;

[0115] R a 、R 2 , W, k1 and k2 are as defined in any one of formula (I) of the present invention.

[0116] In some embodiments, the compounds represented by formula (I), formula (Ia), formula (Ib), and formula (Ib-3) are:

[0117] in,

[0118] R 2 Each independently represents hydrogen, F, Cl, Br, -CN, -CH3, -CF3, -CHF2, -OCH3 or -OCF3; preferably, R 2 are each independently hydrogen, F, Cl or -CH3;

[0119] W is a chemical bond, -O-, -CH2CH2-O-CH2-, -CH2CH2-O-, -CH2-O-CH2CH2-, -CH2-O-, -O-CH2CH2- or -OCH2-; preferably, W is a chemical bond, -O-, -CH2CH2-O-, -O-CH2CH2-, -CH2-O-CH2-, -CH2-O- or -O-CH2-; more preferably, W is -CH2-O- or -O-CH2-;

[0120] R 3 for Preferably, R 3 for More preferably, R 3 for Among them, end a is connected to W.

[0121] In some embodiments, the compounds represented by formula (I), formula (Ia), formula (Ib), and formula (Ib-3) are:

[0122] in,

[0123] for Among them, the a end is connected to the A ring.

[0124] In some embodiments, the structure represented by Formula (I), Formula (Ia), Formula (Ib), or Formula (Ib-3) is a compound represented by (Ib-3a), (Ib-3b), or (Ib-3c):

[0125] in,

[0126] R 2 、R 3 and W are as defined in any one of formula (I) of the present invention.

[0127] In some embodiments, the structure represented by Formula (I), Formula (Ia), or Formula (Ib) is any of the following structures:

[0128] In some embodiments, the present invention provides a ligand-drug conjugate, or a tautomer, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt or solvate thereof, wherein the ligand-drug conjugate comprises a ligand and a structure represented by formula (II):

[0129] in,

[0130] Linker is a connecting subunit that binds to the ligand and can be cleavable or non-cleavable;

[0131] R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of the formula (I) of the present invention.

[0132] In some embodiments, the structure represented by formula (II) is the structure represented by formula (II-1):

[0133] in,

[0134] R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of Formula (I) of the present invention;

[0135] The wavy line indicates the L 1 The nitrogen or carbon atom on the group is connected to the ligand;

[0136] L 1 for: Where a end and L 2 connected;

[0137] L 2 -(C(RL 21 )2) n -,

[0138] Wherein, n is a natural number from 0 to 50, such as 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0139] L 2 Any C(R L21 )2 units are independently replaced by the following structural units: -Cy-, -C(O)-, -NR L22 -, -O-, -S-, -SO-, -SO2-, -P(R L22 )-、-P(=O)(RL22 )-、-(R L22 )P(=O)-, -C(=S)-, -C(=NR L22 )-, -N=N-, -C=N-, -N=C-,

[0140] -Cy- is phenylene, 5- to 8-membered heteroarylene, 3- to 10-membered heterocyclylene, or 3- to 10-membered cycloalkylene, wherein the -Cy- is independently substituted by one or more R cx replace;

[0141] R L21 、R L22 、R cx Each independently selected from hydrogen, deuterium, halogen, -NO2, -CN, -OR L2a 、-SR L2a 、-N(R L2a )2、-N + (R L2a )3, -C(O)R L2a 、-CO2R L2a 、-C(O)C(O)R L2a 、-C(O)CH2C(O)R L2a 、-S(O)R L2a 、-S(O)2R L2a 、-C(O)N(R L2a )2、-SO2N(R L2a )2、-OC(O)R L2a 、-N(R L2a )SO2R L2b 、-N(R L2a )COR L2b 、-(CH2) y -CO-(N(Me)CH2C(O)) m -OR L2a 、-(CH2) y -CO-(N(Me)CH2C(O)) m -NHR L2a 、-(CH2) y -CO-(N(Me)CH2C(O)) m -N + (R L2a )3, -(CH2) y -NHCOCH2(OCH2CH2)OR L2a 、-(CH2) y -NH(COCH2(N(Me)) m -R L2a 、-(CH2)y -CONH-(CH2CH2O) m -R L2a 、-(CH2) y -NHCO-(CH2CH2O) m -R L2a 、-(CH2CH2O) m -R L2a 、-(COCH2N(Me)) m -R L2a 、-COCH2(OCH2CH2) m -OR L2a 、-CO-(CH2CH2O) m -R L2a 、-CO-(CH2) y -CONH-(CH2CH2O) m -R L2a 、-CO-(CH2) y -NHCO-(CH2CH2O) m -R L2a and R L2a Optionally substituted C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl or 3-10 membered heteroaryl;

[0142] m, y are each a natural number from 0 to 50, such as 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0143] R L2a 、R L2b Each independently selected from hydrogen, deuterium, halogen, -NO2, -CN, -OH, -SH, -NH2, -N(Me)2, -CO2H, -S(O)2Me, -S(O)2OH, -C(O)NH2, -SO2NH2, C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl, and 3-10 membered heteroaryl;

[0144] L 3 Does not exist or is an amino acid residue, a short peptide consisting of 2-10 amino acid residues, Or any combination of the above groups, the amino acid residue is a natural amino acid residue or a non-natural amino acid residue; wherein the a end and L 2 Preferably, the amino acid residue and the nitrogen end of the short peptide consisting of 2-10 amino acid residues are connected to L2 connected;

[0145] Tr does not exist or is Or any combination of the above groups; wherein the a end and L 3 connected;

[0146] R Tr 、R Tr1 and R Tr2 Each independently selected from hydrogen, deuterium, halogen, -NO2, -CN, -OH, -SH, -NH2, -CO2H, -S(O)2OH, -C(O)NH2, -SO2NH2, -OC(O)NH2, -CH2CO-(N(Me)CH2C(O)) z -OR Tra 、-CH2CO-(N(Me)CH2C(O)) z -NHR Tra 、-(CH2CH2O) z -R Tra 、-CONH-(CH2CH2O) z -R Tra and R Tra Optionally substituted C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl or 3-10 membered heteroaryl;

[0147] R Tra independently selected from hydrogen, deuterium, halogen, -NO2, -CN, -OH, -SH, -NH2, -N(Me)2, -S(O)2Me, -CO2H, -S(O)2OH, -C(O)NH2, -SO2NH2, C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl, and 3-10 membered heteroaryl;

[0148] z is independently a natural number from 0 to 50; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8.

[0149] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0150] Among them, L 1 Selected from: Preferably, L 1 Selected from Where a end and L 2 connected.

[0151] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0152] Among them, L 2 -(CHR L21 ) n -;

[0153] n is a natural number from 0 to 50; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0154] L 2 Any CH2 unit in the is independently replaced by the following structural units: -Cy-, -C(O)-, -NR L22 -、-O-、

[0155] -Cy- is phenylene, 5- to 6-membered heteroarylene, 4- to 10-membered heterocyclylene, or 3- to 6-membered cycloalkylene, wherein said -Cy- is independently substituted by 1 to 3 R cx replace;

[0156] Each R L21 、R L22 、R cx are independently hydrogen, halogen, -OR L2a 、-N(R L2a )2、-C(O)R L2a 、-S(O)2R L2a 、-C(O)N(R L2a )2、-SO2N(R L2a )2、-N(R L2a )SO2R L2b 、-N(R L2a )COR L2b 、-(CH2) y -CO-(N(Me)CH2C(O)) m -OR L2a 、-(CH2) y -CO-(N(Me)CH2C(O)) m -NHR L2a 、-(CH2) y -CONH-(CH2CH2O) m -R L2a 、-(CH2) y -NHCO-(CH2CH2O) m -R L2a 、-(CH2) y -NHCOCH2(OCH2CH2)OR L2a 、-(CH2) y-NH(COCH2(N(Me)) m -R L2a 、-(CH2) y -NHCO-(CH2CH2O) m -R L2a 、-(CH2CH2O) m -R L2a 、-(COCH2N(Me)) m -R L2a 、-COCH2(OCH2CH2) m -OR L2a 、-CO-(CH2CH2O) m -R L2a , or by R L2a Optionally substituted C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl or 3-10 membered heteroaryl;

[0157] m is a natural integer from 0 to 8;

[0158] y is 0, 1, 2, 3, or 4;

[0159] Each R L2a 、R L2b Each is independently hydrogen, halogen, -CN, -OH, -NH2, -N(Me)2, -CO2H, -C(O)NH2, C 1-6 alkyl.

[0160] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0161] Among them, L 2 -(CH2) n -;

[0162] n is a natural integer from 0 to 50; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0163] L 2 Any methylene unit in the group is independently replaced by the following structural units: 4 to 6 membered heterocyclyl, 3 to 6 membered cycloalkyl, -C(O)-, -NR L22 -、-O-、

[0164] Each R L22 are each independently selected from hydrogen, -OR L2a 、-C(O)R L2a 、-S(O)2R L2a 、-C(O)N(RL2a )2、-SO2N(R L2a )2、-(CH2) y -CO-(N(Me)CH2C(O)) m -OR L2a 、-(CH2) y -CO-(N(Me)CH2C(O)) m -NHR L2a 、-(CH2) y -CONH-(CH2CH2O) m -R L2a 、-(CH2) y -NHCOCH2(OCH2CH2)OR L2a 、-(CH2CH2O) m -R L2a 、-(COCH2N(Me)) m -R L2a 、-COCH2(OCH2CH2) m -OR L2a 、-CO-(CH2CH2O) m -R L2a and R L2a Optionally substituted C 1-6 alkyl;

[0165] m is a natural integer from 0 to 8;

[0166] y is 0, 1, 2, 3, or 4;

[0167] Each R L2a Each is independently hydrogen, halogen, -CN, -OH, -NH2, -N(Me)2, -CO2H, -C(O)NH2, C 1-6 alkyl.

[0168] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0169] Among them, L 2 for:

[0170] Among them, the left side and L 1 connected;

[0171] in,

[0172] n1, n2, n3, n4 are each independently a natural number from 0 to 8; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0173] n5 and n6 are each independently 0 or 1;

[0174] -Cy- is a 4- to 6-membered heterocyclylene or a 3- to 6-membered cycloalkylene; preferably, -Cy- is More preferably, -Cy- is The a-end is connected to the carbonyl group;

[0175] Preferably,

[0176] for

[0177] Among them, the C-terminal and L 1 Connected, d end and L 3 connected.

[0178] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0179] in, for:

[0180] Among them, the right side and L 3 connected;

[0181] n1, n2, n3, n4 are each independently a natural number from 0 to 8; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0182] n5 and n6 are each independently 0 or 1;

[0183] Preferably, for: Among them, the f end and L 3 connected.

[0184] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0185] Among them, L 3 Does not exist or is L 3a -L 3b ;

[0186] L 3a and L 3b Independently, there is no or no amino acid residue, a short peptide consisting of 2-10 amino acid residues, Among them, the a end and L 2 connected.

[0187] In some embodiments, the structures represented by Formula (II-1), Formula (IIa), Formula (IIb), Formula (IIb-1), Formula (IIb-2) and Formula (IIb-3), wherein L 3a With L 2 connected.

[0188] In some embodiments, the structures represented by Formula (II-1), Formula (IIa), Formula (IIb), Formula (IIb-1), Formula (IIb-2) and Formula (IIb-3), wherein L 3a Is absent or selected from Val, D-Val, Phe, Lys, Leu, Ile, Gly, Ala, D-Ala, Cit, Asp, Asn, Glu, Gln, Val-Cit, Val-Ala, Val-Lys, Val-Lys(Ac), Phe-Lys, Phe-Lys(Ac), Leu-Lys, Leu-Lys(Ac), Ala-Ala, Ala-Ly s, D-Ala-Ala, Gly-Glu, Gly-Asp, Gly-Asn, Val-Glu, Val-Asp, Asn-Asn, Asp-Glu, Asp-Ser, Gly-Gly-Glu, Gly-Gly-Asp, Gly-Gly-Asn, Gly-Ala-Ala, Gly-Val-Ala, Gly-Val-Cit, Glu-Val-C it, Ala-Ala-Ala, Ala-(D-Ala)-Ala, Ala-Ala-Asn, Ala-(D-Ala)-Asn, Ala-Ala-Asp, Val-Lys-Gly, D-Val-Leu-Lys, Gly-Gly-Arg, Gly-Gly-Gly, Lys-Ala-Asn, Gly-Phe-Gly, Gly-Gly-Phe, Asn-Pro-Val, Ala-Lys-Gly, Gly-Lys-Gly, Gly-Glu-Gly, (Gly)4, (Gly)2-Phe-Gly, (Gly)2-Glu-Gly, Lys-(Ala)2-Asn, Lys-(Ala)2-Asp, (Ala)2-Pro-Val, and (Ala)2-Pro-Nva; wherein the nitrogen terminus of the amino acid residue is adjacent to L 2 connected;

[0189] L 3b Does not exist or Among them, the a end and L 3a connected.

[0190] In some embodiments, the structures represented by Formula (II-1), Formula (IIa), Formula (IIb), Formula (IIb-1), Formula (IIb-2) and Formula (IIb-3), wherein L 3a is absent or selected from Lys, Gly, Asp, Asn, Glu, Gln, Val-Cit, Val-Ala, Ala-Ala, Gly-Glu, Gly-Asp, Gly-Asn, Asp-Glu, Gly-Glu-Gly and (Gly)2-Phe-Gly; wherein the nitrogen end of the amino acid residue is adjacent to L 2 connected;

[0191] L 3b Does not exist or Among them, the a end and L 3a connected;

[0192] More preferably, L 3a is absent or selected from Val-Cit, Val-Ala, Ala-Ala, Gly-Glu, Gly-Asp, Gly-Asn and (aGly)2-Phe-Gly; wherein the nitrogen end of the amino acid residue is adjacent to L 2 connected;

[0193] L 3b Does not exist or Among them, the a end and L 3a connected.

[0194] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0195] in, for:

[0196] Preferably, for

[0197] More preferably, for

[0198] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0199] Where Tr does not exist or is Among them, the a end and L 3 connected;

[0200] R Tr 、R Tr1 and R Tr2are independently hydrogen, halogen, -NO2, -CN, -OH, -NH2, -CO2H, -S(O)2H, -C(O)NH2, -SO2NH2, -OC(O)NH2, -CH2CO-(N(Me)CH2C(O)) z -NHMe, -(CH2CH2O) z -H, -CONH-(CH2CH2O) z -H;

[0201] z is a natural number from 0 to 8; for example, 0, 1, 2, 3, 4, 5, 6, 7, or 8.

[0202] In some embodiments, the structures represented by formula (II) and formula (II-1) are

[0203] Where Tr does not exist or is Among them, the a end and L 3 connected.

[0204] In some embodiments, the structure represented by formula (II) or formula (II-1) is the structure represented by formula (IIa):

[0205] in,

[0206] R 1 、R a 、R 2 、R 3 , V, L, W, Z, Ring B, k1 and k2 are as defined in any one of Formula (I) of the present invention;

[0207] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0208] In some embodiments, the structures represented by formula (II), formula (II-1) and formula (IIa) are the structures represented by formula (IIb):

[0209] in,

[0210] R a 、R 2 、R 3 , W, Z, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0211] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0212] In some embodiments, the structure represented by formula (II), formula (II-1), formula (IIa), and formula (IIb) is the structure represented by formula (IIb-1):

[0213] in,

[0214] R a 、R 2 , W, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0215] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0216] In some embodiments, the structure represented by Formula (II), Formula (II-1), Formula (IIa), Formula (IIb), or Formula (IIb-1) is the structure represented by Formula (IIb-1a), Formula (IIb-1b), Formula (IIb-1c), Formula (IIb-1d), or Formula (IIb-1e):

[0217] in,

[0218] Ra, R 2 and W are as defined in any one of formula (I) of the present invention;

[0219] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0220] In some embodiments, the structure represented by Formula (II), Formula (II-1), Formula (IIa), and Formula (IIb) is the structure represented by Formula (IIb-2):

[0221] in,

[0222] R a 、R 2 、R 3 , W, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0223] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0224] In some embodiments, the structure represented by Formula (II), Formula (II-1), Formula (IIa), Formula (IIb), or Formula (IIb-2) is the structure represented by Formula (IIb-2a), Formula (IIb-2b), or Formula (IIb-2c):

[0225] in,

[0226] R 2 、R 3 , W is as defined in any one of formula (I) of the present invention;

[0227] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0228] In some embodiments, the structure represented by formula (II), formula (II-1), formula (IIa), and formula (IIb) is the structure represented by formula (IIb-3):

[0229] in,

[0230] R a 、R 2 、R 3 , W, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0231] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0232] In some embodiments, the structure represented by Formula (II), Formula (II-1), Formula (IIa), Formula (IIb), or Formula (IIb-3) is the structure represented by Formula (IIb-3a), Formula (IIb-3b), or Formula (IIb-3c):

[0233] R 2 、R 3 and W are as defined in any one of formula (I) of the present invention;

[0234] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0235] In some embodiments, the structure represented by formula (II), (II-1) or formula (IIa) is any of the following structures:

[0236] In some embodiments, the present invention provides a ligand-drug conjugate as represented by formula (III), or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or pharmaceutically acceptable salts thereof:

[0237] in,

[0238] Ab is the ligand that binds to the target;

[0239] q is the drug loading (drug-antibody coupling ratio);

[0240] R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of Formula (I) of the present invention;

[0241] The linker is as described in any one of formula (II) of the present invention.

[0242] In addition, it should be noted that the linker is connected to the Ab through the S atom. Those skilled in the art will understand that the linker is connected to the sulfhydryl group contained in the Ab after the disulfide bond is opened. In other words, the -S- between the linker and the Ab is not an additional external sulfur atom. In the example, -S- is not an additional external sulfur atom, but the sulfhydryl group contained in the Ab itself after the disulfide bond is opened and the linker is connected. -S- is formed by connecting the a-end of the molecule.

[0243] In some embodiments, the ligand-drug conjugate has a structure represented by formula (III), wherein Ab is a target-binding polypeptide, antibody, or antigen-binding fragment thereof.

[0244] In some preferred embodiments, the ligand-drug conjugate has a structure represented by formula (III), wherein Ab is an antibody or an antigen-binding fragment thereof.

[0245] In some embodiments, in the ligand-drug conjugate of the structure represented by formula (III), Ab, the antibody is selected from one or more of the following:

[0246] (1) Fully human antibodies, humanized antibodies, mouse antibodies and chimeric antibodies;

[0247] (2) Probody;

[0248] (3) Bispecific antibodies and multispecific antibodies;

[0249] (4) Monoclonal antibodies and polyclonal antibodies;

[0250] (5)IgG antibodies.

[0251] In some embodiments, in the ligand-drug conjugate of the structure represented by formula (III), in Ab, the antigen-binding fragment is selected from the group consisting of: Fab, Fab', F(ab')2, Fv, scFv, Fd, dAb, VHH and complementarity determining region (CDR) fragments.

[0252] In some embodiments, the ligand-drug conjugate has a structure represented by formula (III), wherein Ab is a monoclonal antibody.

[0253] In some preferred embodiments, the ligand-drug conjugate of the structure represented by formula (III), wherein the Ab targets an antigen selected from the group consisting of HER2, HER3, B7H3, B7H4, DLL3, TROP2, Claudin18.2, CD30, CD33, CD70, GPC-3, ADAM9, and EGFR.

[0254] In some embodiments, the ligand-drug conjugate of the structure represented by formula (III), wherein Ab is an antibody or antigen-binding fragment thereof targeting HER3, B7H3, Claudin18.2, CD30, CD33, CD70, GPC-3, ADAM9 and EGFR.

[0255] In some preferred embodiments, the ligand-drug conjugate has a structure represented by formula (III), wherein Ab is an antibody or an antigen-binding fragment thereof targeting HER3, for example, Patritumab or a variant thereof.

[0256] In some embodiments, the ligand-drug conjugate has a structure represented by formula (III), wherein Ab is an anti-GPC-3 antibody or an antigen-binding fragment thereof, for example, codrituzumab or a variant thereof.

[0257] In some embodiments, the ligand-drug conjugate of the structure shown in Formula (III), wherein the anti-Her3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, the heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 with amino acid sequences as shown in SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 3, respectively, and the light chain variable region comprises LCDR1, LCDR2 and LCDR3 with amino acid sequences as shown in SEQ ID NO: 4, SEQ ID NO: 5 and SEQ ID NO: 6, respectively.

[0258] In some embodiments, the ligand-drug conjugate of the structure represented by formula (III), wherein the anti-HER3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, the heavy chain variable region amino acid sequence is as shown in SEQ ID NO: 7 or a sequence having at least 95%, 96%, 97%, 98% or 99% identity thereto, and the light chain variable region amino acid sequence is as shown in SEQ ID NO: 8 or a sequence having at least 95%, 96%, 97%, 98% or 99% identity thereto;

[0259] In some embodiments, the ligand-drug conjugate with a structure represented by formula (III), wherein the anti-HER3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, the amino acid sequence of the heavy chain variable region is shown in SEQ ID NO: 7, and the amino acid sequence of the light chain variable region is shown in SEQ ID NO: 8.

[0260] In some embodiments, the ligand-drug conjugate has a structure represented by formula (III), wherein the anti-HER3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain of the antibody, wherein the amino acid sequence of the heavy chain is as shown in SEQ ID NO: 9 or a sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto, and the amino acid sequence of the light chain is as shown in SEQ ID NO: 10 or a sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto.

[0261] In some embodiments, the ligand-drug conjugate of the structure represented by formula (III), wherein the anti-HER3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain of the antibody, wherein the amino acid sequence of the heavy chain is as shown in SEQ ID NO: 9, and the amino acid sequence of the light chain is as shown in SEQ ID NO: 10.

[0262] In some embodiments, the ligand-drug conjugate has a structure represented by formula (III), wherein Ab is preferably an anti-GPC-3 antibody or an antigen-binding fragment thereof, for example, codrituzumab or a variant thereof.

[0263] In some embodiments, the ligand-drug conjugate has a structure represented by Formula (III), wherein the anti-GPC-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region comprises HCDR1, HCDR2, and HCDR3 with amino acid sequences as shown in SEQ ID NO: 11, SEQ ID NO: 12, and SEQ ID NO: 13, respectively, and the light chain variable region comprises LCDR1, LCDR2, and LCDR3 with amino acid sequences as shown in SEQ ID NO: 14, SEQ ID NO: 15, and SEQ ID NO: 16, respectively.

[0264] In some embodiments, the ligand-drug conjugate of formula (III) comprises an anti-GPC-3 antibody or antigen-binding fragment thereof comprising a heavy chain variable region and a light chain variable region, wherein the amino acid sequence of the heavy chain variable region is as shown in SEQ ID NO: 17 or a sequence having at least 95%, 96%, 97%, 98% or 99% identity thereto, and the amino acid sequence of the light chain variable region is as shown in SEQ ID NO: 18 or a sequence having at least 95%, 96%, 97%, 98% or 99% identity thereto;

[0265] In some embodiments, the ligand-drug conjugate of the structure represented by formula (III) comprises an anti-GPC-3 antibody or antigen-binding fragment thereof comprising a heavy chain variable region and a light chain variable region, wherein the amino acid sequence of the heavy chain variable region is as shown in SEQ ID NO: 17, and the amino acid sequence of the light chain variable region is as shown in SEQ ID NO: 18.

[0266] In some embodiments, the ligand-drug conjugate has a structure represented by Formula (III), wherein the anti-GPC-3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain of the antibody, wherein the amino acid sequence of the heavy chain is as shown in SEQ ID NO: 19, or a sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto, and the amino acid sequence of the light chain is as shown in SEQ ID NO: 20, or a sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto.

[0267] In some embodiments, the ligand-drug conjugate of the structure represented by formula (III) comprises an anti-GPC-3 antibody or antigen-binding fragment thereof comprising a heavy chain and a light chain of the antibody, wherein the amino acid sequence of the heavy chain is as shown in SEQ ID NO: 19, and the amino acid sequence of the light chain is as shown in SEQ ID NO: 20.

[0268] In some embodiments, the ligand-drug conjugate has a structure represented by formula (III), wherein q is an integer or decimal of 1-32, preferably an integer or decimal of 1-16, more preferably an integer or decimal of 2-8, for example, 2, 3, 4, 5, 6, 7, 8, 7.5, 7.6, 7.7, 7.8 or 7.9; for example, 7.53, 7.64, 7.67 or 7.89.

[0269] In some embodiments, the ligand-drug conjugate of the structure represented by formula (III) is a ligand-drug conjugate represented by formula (III-1):

[0270] in,

[0271] R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of Formula (I) of the present invention;

[0272] L 1 , L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0273] Ab and q are as described in any one of formula (III) of the present invention.

[0274] In some embodiments, the ligand-drug conjugate of the structure represented by formula (III) or formula (III-1) is a ligand-drug conjugate represented by formula (IIIa):

[0275] in,

[0276] R 1 、R a 、R 2 、R 3 , V, L, W, Z, Ring B, k1 and k2 are as defined in any one of Formula (I) of the present invention;

[0277] L 1 , L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0278] Ab and q are as described in any one of formula (III) of the present invention.

[0279] In some embodiments, the ligand-drug conjugate of the structure represented by formula (III), formula (III-1), or formula (IIIa) is a ligand-drug conjugate represented by formula (IIIb):

[0280] in,

[0281] R a 、R 2 、R 3 , W, Z, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0282] L 1 , L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0283] Ab and q are as described in any one of formula (III) of the present invention.

[0284] In some embodiments, the ligand-drug conjugate of the structure represented by Formula (III), Formula (III-1), Formula (IIIa), or Formula (IIIb) is a ligand-drug conjugate represented by Formula (IIIb-1):

[0285] in,

[0286] R a 、R 2 , W, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0287] L 1 , L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0288] Ab and q are as described in any one of formula (III) of the present invention.

[0289] In some embodiments, the structures represented by Formula (III), Formula (III-1), Formula (IIIa), Formula (IIIb), and Formula (IIIb-1) are structures represented by Formula (IIIb-1a), Formula (IIIb-1b), Formula (IIIb-1c), Formula (IIIb-1d), and Formula (IIIb-1e):

[0290] in,

[0291] R a 、R2 and W are as defined in any one of formula (I) of the present invention;

[0292] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0293] Ab and q are as described in any one of formula (III) of the present invention.

[0294] In some embodiments, the ligand-drug conjugate of the structure represented by Formula (III), Formula (III-1), Formula (IIIa), or Formula (IIIb) is a ligand-drug conjugate represented by Formula (IIIb-2):

[0295] in,

[0296] R a 、R 2 、R 3 , W, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0297] L 1 , L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0298] Ab and q are as described in any one of formula (III) of the present invention.

[0299] In some embodiments, the structures represented by Formula (III), Formula (III-1), Formula (IIIa), Formula (IIIb), and Formula (IIIb-2) are the structures represented by Formula (IIIb-2a), Formula (IIIb-2b), and Formula (IIIb-2c):

[0300] in,

[0301] R 2 、R 3 , W is as defined in any one of formula (I) of the present invention;

[0302] L 1 , L 2 , L 3 and Tr are as described in any one of formula (II-1) of the present invention.

[0303] Ab and q are as described in any one of formula (III) of the present invention.

[0304] In some embodiments, the structure represented by Formula (III), Formula (III-1), Formula (IIIa), and Formula (IIIb) is the structure represented by Formula (IIIb-3):

[0305] in,

[0306] R a 、R 2 , W, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0307] R 3 As described in any one of formula (Ib-3) of the present invention;

[0308] L 1 , L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0309] Ab and q are as described in any one of formula (III) of the present invention.

[0310] In some embodiments, the structures represented by Formula (III), Formula (III-1), Formula (IIIa), Formula (IIIb), and Formula (IIIb-3) are the structures represented by Formula (IIIb-3a), Formula (IIIb-3b), and Formula (IIIb-3c):

[0311] R 2 、R 3 and W are as defined in any one of formula (I) of the present invention;

[0312] L 1 , L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0313] Ab and q are as described in any one of formula (III) of the present invention.

[0314] In some embodiments, the ligand-drug conjugate of formula (III), formula (III-1), formula (IIIa), formula (IIIb), formula (IIIb-1), formula (IIIb-2), and formula (IIIb-3) is any of the following compounds:

[0315] wherein Ab and q are as described in any one of formula (III) of the present invention.

[0316] In some preferred embodiments, the ligand-drug conjugate of formula (III), formula (III-1), formula (IIIa), formula (IIIb), formula (IIIb-1), formula (IIIb-2), and formula (IIIb-3) is any of the following compounds:

[0317] in,

[0318] qAs described in any one of the present invention;

[0319] Ab1 and Ab2 are each independently selected from Patritumab or a variant thereof and Codrituzumab or a variant thereof;

[0320] Preferably, Abl is pertratuzumab; Abl is coltuzumab.

[0321] In another aspect, the present invention further provides a nitrogen-containing heterocyclic compound represented by formula (IV), or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or pharmaceutically acceptable salts thereof:

[0322] in,

[0323] linker 1 A linker unit that binds to the ligand;

[0324] R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of the formula (I) of the present invention.

[0325] In some embodiments, the compound of formula (IV) is a compound of formula (IV-1):

[0326] in,

[0327] R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of Formula (I) of the present invention;

[0328] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0329] L1a for:

[0330] In some embodiments, the compounds represented by the structures of formula (IV) and formula (IV-1) are

[0331] Among them, L 1a for: Preferably, L 1a for

[0332] In some embodiments, the compounds represented by the structures of formula (IV) and formula (IV-1) are

[0333] in, for:

[0334] n1, n2, n3, n4 are each independently a natural number from 0 to 8; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8;

[0335] n5 and n6 are each independently 0 or 1;

[0336] Preferably, for: In some embodiments, the compounds represented by the structures of formula (IV) and formula (IV-1) are

[0337] in, for:

[0338] Preferably, Selected from

[0339] More preferably, for

[0340] In some embodiments, the compound represented by formula (IV) or formula (IV-1) is a compound represented by formula (IVa):

[0341] in,

[0342] R 1 、R a 、R 2 、R 3 , V, L, W, Z, Ring B, k1 and k2 are as defined in any one of Formula (I) of the present invention;

[0343] L 2 , L3 and Tr is as described in any one of formula (II-1) of the present invention;

[0344] L 1a As described in any one of formula (IV-1) of the present invention.

[0345] In some embodiments, the compound represented by the structure of formula (IV), formula (IV-1) and formula (IVa) is a compound represented by formula (IVb):

[0346] in,

[0347] R a 、R 2 、R 3 , W, Z, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0348] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0349] L 1a As described in any one of formula (IV-1) of the present invention.

[0350] In some embodiments, the compound represented by the structure of formula (IV), formula (IV-1), formula (IVa), or formula (IVb) is a compound represented by formula (IVb-1):

[0351] in,

[0352] R a 、R 2 , W, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0353] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0354] L 1a As described in any one of formula (IV-1) of the present invention.

[0355] In some embodiments, the compounds represented by the structures of formula (IV), formula (IV-1), formula (IVa), formula (IVb), and formula (IVb-1) are compounds represented by formula (IVb-1a), formula (IVb-1b), formula (IVb-1c), formula (IVb-1d), and formula (IVb-1e):

[0356] in,

[0357] R 2 and W are as defined in any one of formula (I) of the present invention;

[0358] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0359] L 1a As described in any one of formula (IV-1) of the present invention.

[0360] In some embodiments, the compound represented by the structure of formula (IV), formula (IV-1), formula (IVa), or formula (IVb) is a compound represented by formula (IVb-2):

[0361] in,

[0362] R a 、R 2 、R 3 , W, k1 and k2 are as defined in any one of formula (I) and formula (Ib-2) of the present invention;

[0363] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0364] L 1a As described in any one of formula (IV-1) of the present invention.

[0365] In some embodiments, the compounds represented by formula (IV), formula (IV-1), formula (IVa), formula (IVb), and formula (IVb-2) are compounds represented by formula (IVb-2a), formula (IVb-2b), and formula (IVb-2c):

[0366] in,

[0367] R 2 、R 3 , W are as defined in any one of formula (I) and formula (Ib-2) of the present invention;

[0368] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0369] L 1a As described in any one of formula (IV-1) of the present invention.

[0370] In some embodiments, the compound represented by the structure of formula (IV), formula (IV-1), formula (IVa), or formula (IVb) is a compound represented by formula (IVb-3):

[0371] in,

[0372] R a 、R 2 , W, k1 and k2 are as defined in any one of formula (I) of the present invention;

[0373] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0374] L 1a As described in any one of formula (IV-1) of the present invention.

[0375] In some embodiments, the compounds represented by the structures of formula (IV), formula (IV-1), formula (IVa), formula (IVb), and formula (IVb-3) are compounds represented by formula (IVb-3a), formula (IVb-3b), and formula (IVb-3c):

[0376] in,

[0377] R 2 , W is as defined in any one of formula (I) of the present invention;

[0378] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0379] L 1a As described in any one of formula (IV-1) of the present invention.

[0380] In some embodiments, the nitrogen-containing heterocyclic compound represented by formula (IV), formula (IV-1), formula (IVa), formula (IVb), formula (IVb-1), formula (IVb-2), and formula (IVb-3) is any of the following compounds:

[0381] The present invention also provides a nitrogen-containing heterocyclic compound as shown in Formula V, or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts, or its solvates, or its pharmaceutically acceptable salts of solvates:

[0382] in,

[0383] R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of the formula (I) of the present invention.

[0384] In some embodiments, the compound of formula (V) is a compound of formula (Va):

[0385] in,

[0386] R 1 、R a 、R 2 、R 3 , V, L, W, Z, Ring B, k1 and k2 are as defined in any one of the formula (I) of the present invention.

[0387] In some embodiments, the compound represented by the structure of formula (V) and formula (Va) is a compound represented by formula (Vb):

[0388] in,

[0389] R a 、R 2 、R 3 , W, Z, k1 and k2 are as defined in any one of formula (I) of the present invention.

[0390] In some embodiments, the compound represented by the structure of formula (V), formula (Va), or formula (Vb) is a compound represented by formula (Vb-1):

[0391] in,

[0392] R a 、R 2 , W, k1 and k2 are as defined in any one of formula (I) and formula (Vb) of the present invention.

[0393] In some embodiments, the compound represented by the structure of formula (V), formula (Va), formula (Vb), or formula (Vb-1), wherein:

[0394] R 2 Each is independently H, F, Cl, -CH3, -O-phenyl, -S-phenyl or -O-CH2-phenyl;

[0395] W is -NH-, -CH2CH2-O-CH2CH2-N(CH3)- or -O-CH2CH2-N(CH3)-;

[0396] Or, W and R 2 Together with its connected N and C atoms, it forms Side a is connected to ring B in a ring-like manner.

[0397] In some embodiments, the compound represented by formula (V), formula (Va), formula (Vb), or (Vb-1) is represented by formula (Vb-1a), (Vb-1b), or (Vb-1c): R 2 and W are as defined in any one of formula (I) of the present invention.

[0398] In some embodiments, the compound represented by the structure of formula (V), formula (Va), or formula (Vb) is a compound represented by formula (Vb-2):

[0399] in,

[0400] R a 、R 2 、R 3 , W, k1 and k2 are as defined in any one of formula (I) and formula (Vb) of the present invention.

[0401] In some embodiments, the compound represented by the structure of formula (V), formula (Va), formula (Vb), or formula (Vb-2): wherein,

[0402] R 2 are each independently hydrogen, F or Cl;

[0403] W is -O-, -S-, or -CH2-O-;

[0404] R 3 It is a phenylene group.

[0405] In some embodiments, the compound represented by the structure of Formula (V), Formula (Va), Formula (Vb), or Formula (Vb-2) is a compound represented by (Vb-2a), (Vb-2b), or (Vb-2c):

[0406] in,

[0407] R 2 、R 3 and W are as defined in any one of formula (I) of the present invention.

[0408] In some embodiments, the compound represented by the structure of formula (V), formula (Va), or formula (Vb) is a compound represented by formula (Vb-3):

[0409] in,

[0410] R a 、R 2 、R 3 , W, k1 and k2 are as defined in any one of formula (I) and formula (Vb) of the present invention;

[0411] In some embodiments, the compounds represented by formula (I), formula (Ia), formula (Ib), and formula (Ib-3) are:

[0412] in,

[0413] R 2 are each independently hydrogen, F, Cl or -CH3;

[0414] W is -CH2CH2-O-, -O-CH2CH2-, -CH2-O- or -O-CH2-;

[0415] R 3 for Among them, end a is connected to W.

[0416] In some embodiments, the compounds represented by formula (V), formula (Va), formula (Vb), and formula (Vb-3) are represented by compounds (Vb-3a), (Vb-3b), and (Vb-3c):

[0417] in,

[0418] R 2 、R 3 and W are as defined in any one of formula (I) of the present invention.

[0419] In some embodiments, the nitrogen-containing heterocyclic compound represented by Formula (V), Formula (Va), Formula (Vb), Formula (Vb-1), Formula (Vb-2), and Formula (Vb-3) is any of the following compounds:

[0420] The present invention also provides a method for preparing a ligand-drug conjugate as shown in formula (III-1), comprising the following steps: subjecting a nitrogen-containing heterocyclic compound as shown in formula (IV-1) to a substitution or addition reaction with Ab-SH to obtain the ligand-drug conjugate as shown in formula (III-1);

[0421] in,

[0422] R 1 、R 2 、R 3, V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of Formula (I) of the present invention;

[0423] L 1 , L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0424] L 1a As described in any one of formula (IV-1) of the present invention;

[0425] Ab and q are as described in any one of formula (III) of the present invention;

[0426] The Ab-SH is a product in which the interchain disulfide bonds of Ab are reduced to sulfhydryl groups.

[0427] In one embodiment, the method for preparing the ligand-drug conjugate as shown in formula (III-1) further comprises the following steps: reacting a nitrogen-containing heterocyclic compound as shown in formula (V) with L 1a -L 2 -L 3 -Tr-Lg 1 Through nucleophilic substitution or condensation reaction, a nitrogen-containing heterocyclic compound as shown in formula (IV-1) is obtained;

[0428] in,

[0429] Lg 1 is a leaving group, such as halogen, hydroxyl, wait.

[0430] In a certain embodiment, in the method for obtaining the nitrogen-containing heterocyclic compound as shown in formula (IV-1), the condensation reaction further comprises a condensing agent, which can be a conventional condensing agent for such reactions in the art, preferably 4-(4,6-dimethoxy-1,3,5-triazine-2-yl)-4-methylmorpholinium chloride, 1-hydroxybenzotriazole, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroborate, 1-hydroxybenzotriazole , 1-hydroxy-7-azobenzotriazole, O-benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate, 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate, benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate and benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate, for example, one or more of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, 1-hydroxybenzotriazole and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride.

[0431] In one embodiment, in the method for obtaining the nitrogen-containing heterocyclic compound represented by formula (IV-1), the condensation reaction or substitution reaction further comprises a base, which can be a conventional alkaline base for such reactions in the art, preferably triethylamine, NMM or DIPEA.

[0432] In one embodiment, the method for preparing the ligand-drug conjugate of formula (III-1) further comprises the following steps: 1. intermolecular condensation of formula (V)-1 and formula (V)-2 in the presence of a condensing agent to obtain formula (V)-3; 2. acid deprotection, base deprotection, or reduction reaction of formula (V)-3 in the presence of a metal catalyst to obtain a nitrogen-containing heterocyclic compound of formula (V);

[0433] in,

[0434] Pg 1 is a nitrogen protecting group, such as Boc, Fmoc or Cbz; or is a nitro group;

[0435] Pg 2 is a protecting group for hydrogen or nitrogen, such as Boc, Fmoc or Cbz.

[0436] In one embodiment, in the method for obtaining formula (V)-3, the condensing agent can be a condensing agent commonly used in this type of reaction in the art, preferably CDI, phosgene or triphosgene.

[0437] In one embodiment, in the nitrogen-containing heterocyclic compound obtained as shown in formula (V)-3, the base can be a conventional base for such reactions in the art, preferably one or more of piperidine, ethanolamine, morpholine, ethylenediamine and piperazine.

[0438] In one embodiment, in the nitrogen-containing heterocyclic compound represented by formula (V), the acid can be a conventional acid for such reactions in the art, preferably one or more of trifluoroacetic acid, hydrogen chloride, methanesulfonic acid and p-toluenesulfonic acid.

[0439] In one embodiment, in the nitrogen-containing heterocyclic compound represented by formula (V), the metal catalyst can be a conventional metal catalyst for such reactions in the art, preferably Pd / C, Pd(OH)2 or Ni.

[0440] The present invention also provides a method for preparing a nitrogen-containing heterocyclic compound as shown in formula (IV-1), which comprises the following steps: 1. reacting a nitrogen-containing heterocyclic compound as shown in formula (V) with Pg 3 -L 2 -L 3 -Tr-Lg 1 After the substitution reaction, a nitrogen-containing heterocyclic compound as shown in formula (IV-1)-1 is obtained; 2. The nitrogen-containing heterocyclic compound as shown in formula (IV-1)-1 is subjected to acid or base deprotection to obtain a nitrogen-containing heterocyclic compound as shown in formula (IV-1)-2; 3. The nitrogen-containing heterocyclic compound as shown in formula (IV-1-2) is reacted with L a -Lg 2 A nitrogen-containing heterocyclic compound represented by formula (IV-1) is obtained through a condensation reaction or a substitution reaction;

[0441] in,

[0442] Lg 2 is a leaving group, such as halogen, hydroxyl,

[0443] Pg 3 is a nitrogen protecting group, such as Boc, Fmoc or Cbz;

[0444] R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of Formula (I) of the present invention;

[0445] L 2 , L 3 and Tr is as described in any one of formula (II-1) of the present invention;

[0446] L 1aAs described in any one of formula (IV-1) of the present invention.

[0447] In one embodiment, in the method for obtaining formula (IV-1)-1, the substitution reaction further comprises a base, which can be a conventional base for such reactions in the art, preferably triethylamine, DIEA or NMM.

[0448] In one embodiment, in the method for obtaining the compound of formula (IV-1)-2, the base may be a conventional base for such reactions in the art, preferably one or more of piperidine, ethanolamine, morpholine, ethylenediamine and piperazine.

[0449] In one embodiment, in the method for obtaining the compound of formula (IV-1)-2, the acid may be a conventional acid for such reactions in the art, preferably one or more of trifluoroacetic acid, hydrogen chloride, methanesulfonic acid and p-toluenesulfonic acid.

[0450] In a certain embodiment, the obtained nitrogen-containing heterocyclic compound as shown in formula (IV-1), the condensation reaction further comprises a condensing agent, and the condensing agent can be a conventional condensing agent for such reactions in the art, preferably 4-(4,6-dimethoxy-1,3,5-triazine-2-yl)-4-methylmorpholinium chloride, 1-hydroxybenzotriazole, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, O-benzotriazole-N,N,N',N'-tetramethyluronium tetrafluoroborate, 1-hydroxybenzotriazole, One or more of 1-hydroxy-7-azobenzotriazole, O-benzotriazole-N,N,N',N'-tetramethyluronium hexafluorophosphate, 2-(7-azobenzotriazole)-N,N,N',N'-tetramethyluronium hexafluorophosphate, benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate, and benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate, such as one or more of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride, 1-hydroxybenzotriazole, and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride.

[0451] The present invention also provides a method for preparing a ligand-drug conjugate as shown in formula (IV-1), which comprises the following steps: reacting a nitrogen-containing heterocyclic compound as shown in formula (V) with L 1a -L 2 -L 3 -Tr-Lg 1 Through nucleophilic substitution or condensation reaction, a nitrogen-containing heterocyclic compound as shown in formula (IV-1) is obtained;

[0452] In one embodiment, the conditions and steps for preparing the nitrogen-containing heterocyclic compound represented by formula (IV-1) are the same as those described above.

[0453] The present invention also provides a method for preparing a ligand-drug conjugate as shown in formula (V), comprising the following steps: 1. intermolecular condensation of formula (V)-1 and formula (V)-2 in the presence of a condensing agent to obtain formula (V)-3; 2. acid deprotection, base deprotection or reduction reaction of formula (V)-3 in the presence of a metal catalyst to obtain a nitrogen-containing heterocyclic compound as shown in formula (V);

[0454] In one embodiment, the conditions and steps for preparing the nitrogen-containing heterocyclic compound represented by formula (V) are the same as those described above.

[0455] The present invention also provides a pharmaceutical composition comprising a substance S and one or more pharmaceutical excipients;

[0456] The substance S is any of the ligand-drug conjugates described above, or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or pharmaceutically acceptable salts thereof; or

[0457] Any nitrogen-containing heterocyclic compound as described above, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof.

[0458] The present invention also provides a use of a substance S in preparing a drug for preventing or treating cancer;

[0459] The substance S is any of the ligand-drug conjugates described above, or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or pharmaceutically acceptable salts thereof; or

[0460] Any nitrogen-containing heterocyclic compound as described above, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof.

[0461] Preferably, the cancer is a solid tumor or a non-solid tumor, such as esophageal cancer (e.g., esophageal adenocarcinoma and esophageal squamous cell carcinoma), brain tumor, lung cancer (e.g., small cell lung cancer and non-small cell lung cancer), squamous cell carcinoma, bladder cancer, gastric cancer, ovarian cancer, peritoneal cancer, pancreatic cancer, breast cancer, head and neck cancer, cervical cancer, endometrial cancer, colorectal cancer, liver cancer, kidney cancer, non-Hodgkin's lymphoma, central nervous system tumor (e.g., glioma, glioblastoma multiforme, glioma or sarcoma), prostate cancer or thyroid cancer.

[0462] The present invention also provides a use of a substance S in the preparation of a medicament for preventing or treating a disease associated with abnormal cell activity;

[0463] The substance S is any of the ligand-drug conjugates described above, or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or pharmaceutically acceptable salts thereof; or

[0464] Any nitrogen-containing heterocyclic compound as described above, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof.

[0465] Preferably, the disease associated with abnormal cell activity may be cancer; more preferably, the definition of cancer is as described above.

[0466] The present invention also provides a method for preventing or treating cancer, comprising administering an effective amount of substance S to an individual in need thereof;

[0467] The substance S is any of the ligand-drug conjugates described above, or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or pharmaceutically acceptable salts thereof; or

[0468] Any nitrogen-containing heterocyclic compound as described above, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof;

[0469] The cancer is defined as described above.

[0470] The present invention also provides a method for preventing or treating a disease associated with abnormal cell activity, the method comprising administering an effective amount of substance S to an individual in need thereof;

[0471] The substance S is any of the ligand-drug conjugates described above, or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or pharmaceutically acceptable salts thereof; or

[0472] Any nitrogen-containing heterocyclic compound as described above, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof.

[0473] Preferably, the disease associated with abnormal cell activity may be cancer, as defined above.

[0474] In another aspect, the present invention provides a substance S for treating cancer; the substance S is any of the ligand-drug conjugates described above or any of the nitrogen-containing heterocyclic compounds described above, or its tautomers, mesomers, racemates, enantiomers, diastereomers, or mixtures thereof, or a pharmaceutically acceptable salt thereof, or the above-mentioned pharmaceutical composition.

[0475] The disease associated with abnormal cell activity may be cancer. The definition of cancer is as described above.

[0476] Definition of terms:

[0477] Throughout this application, unless otherwise indicated, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Furthermore, the laboratory procedures for cell culture, molecular genetics, nucleic acid chemistry, and immunology used herein are conventional procedures widely used in the relevant fields. To facilitate a better understanding of this disclosure, definitions and explanations of relevant terms are provided below.

[0478] In this application, the term "pharmaceutical excipients" refers to excipients and additives used in the production of pharmaceuticals and the preparation of prescriptions. These substances, in addition to the active ingredients, have been reasonably evaluated for safety and are included in pharmaceutical preparations. In addition to providing shape, acting as carriers, and improving stability, pharmaceutical excipients also have important functions such as solubilization, dissolution assistance, and sustained-release control. They are important ingredients that may affect the quality, safety, and efficacy of drugs. Based on their source, they can be divided into natural, semi-synthetic, and fully synthetic. According to their functions and uses, they can be divided into: solvents, propellants, solubilizers, cosolvents, emulsifiers, colorants, adhesives, disintegrants, fillers, lubricants, wetting agents, osmotic pressure regulators, stabilizers, glidants, flavoring agents, preservatives, suspending agents, coating materials, fragrances, anti-adhesives, antioxidants, chelating agents, penetration enhancers, pH regulators, buffers, plasticizers, surfactants, foaming agents, defoaming agents, thickeners, inclusion agents, humectants, absorbents, diluents, flocculants and deflocculants, filter aids, release retardants, etc. According to their route of administration, they can be divided into oral, parenteral, mucosal, transdermal or topical administration, nasal or oral inhalation administration, and ocular administration, etc. The same pharmaceutical excipient can be used in pharmaceutical preparations for different routes of administration and have different functions and uses.

[0479] In this application, the term "pharmaceutical composition" refers to various dosage forms that can be prepared according to the route of administration, such as tablets, capsules, granules, oral solutions, oral suspensions, oral emulsions, powders, tinctures, syrups, injections, suppositories, ointments, creams, pastes, ophthalmic preparations, pills, implants, aerosols, powder sprays, sprays, etc.

[0480] The pharmaceutical composition can be administered in the form of an injection, including an injection solution, sterile powder for injection, and concentrated solution for injection. Among them, the carriers and solvents that can be used include water, Ringer's solution, and isotonic sodium chloride solution. In addition, sterile fixed oils such as monoglycerides or diglycerides can also be used as solvents or suspending media.

[0481] In this application, the term "pharmaceutically acceptable salt" or "pharmaceutically usable salt" generally refers to a salt of a compound or ligand-drug conjugate of the present application, which salt may be safe and / or effective when used in mammals and may have the desired biological activity.

[0482] The term "drug loading" generally refers to the average amount of cytotoxic drug loaded per ligand and can also be expressed as the ratio of the amount of cytotoxic drug to the amount of antibody, for example, the drug / antibody ratio (DAR). The cytotoxic drug loading can range from 0 to 20, as an integer or decimal. In embodiments of the present application, the drug loading is expressed as q, which can be, for example, an integer or decimal of 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, or 9-10. For example, the drug loading q is 7.5, 7.6, 7.7, 7.8, or 7.9; another example is q is 7.53, 7.64, 7.67, or 7.89. The drug loading of each ADC molecule after the coupling reaction can be determined using conventional methods such as UV / visible spectroscopy, mass spectrometry, HIC, ELISA assay, and HPLC characterization.

[0483] In this application, the term "ligand-drug conjugate" generally refers to a ligand linked to a biologically active cytotoxic drug via a stable linker. In some embodiments of this application, the "ligand-drug conjugate" may be an antibody-drug conjugate (ADC), which may be a monoclonal antibody or antigen-binding fragment linked to a biologically active cytotoxic drug via a stable linker.

[0484] In this application, the term "ligand" generally refers to small molecules, polypeptides, RNA, DNA, carbohydrates and macromolecular compounds that can recognize and bind to antigens or receptors associated with target cells. The function of the ligand can be to present the drug to the target cell population bound to the ligand. These ligands include but are not limited to protein hormones, lectins, growth factors, antibodies or other molecules that can bind to cells, receptors and / or antigens. In this application, the ligand can be represented by Ab, and the ligand antigen forms a connection bond with a connecting unit (also called "linker" or "linker") through a heteroatom on the ligand. The ligand can be an antibody or an antigen-binding fragment thereof. The antibody can be selected from a chimeric antibody, a humanized antibody, a fully human antibody or a murine antibody; the antibody can be a monoclonal antibody. For example, the antibody can be an antibody targeting a target selected from the following targets: HER2, HER3, B7H3, TROP2, Claudin 18.2, CD30, CD33, CD70 and EGFR. For example, the antibody can be an antibody targeting a target selected from the group consisting of 5T4, AGS-16, ANGPTL4, ApoE, CD19, CTGF, CXCR5, FGF2, MCPT8, MFI2, MS4A7, NCA, Sema5b, SLITRK6, STC2, TGF, 0772P, 5T4, ACTA2, ADGRE1, AG-7, AIF1, AKR1C1, AKR1C2, ASLG659, Axl, B7H3, BAFF-R, BCMA, BMPR1B, BNIP3, C1QA, C1QB, CA6, CADM1, CCD79b, CCL5, CCR5, CCR7, CD11c, CD123, CD138, CD142, CD147, CD166, CD19, CD19,CD22, CD21, CD20, CD205, CD22, CD223, CD228, CD25, CD30, CD33, CD37, CD38, CD40, CD45, CD45(PTPRC), CD46, CD47, CD49D(ITGA4), CD56, CD66e, CD70, CD71, CD72, CD74, CD79a, CD79b, CD80, CDCP1, CDH11, CDllb, CEA, CEACAM5, c-Met, COL6A3, COL7A1, CRIPTO, CSF1R, CTSD, CTSS, CXCL11, CXCL10, DDIT4 , DLL3, DLL4, DR5, E16, EFNA4, EGFR, EGFRvIII, EGLN, EGLN3, EMR2, ENPP3, EpCAM, EphA2, EphB2R, ETBR, FcRH2, FcRHl, FGFR2, FGFR3, FLT3, FOLR-α, GD2 , GEDA, GPC-1, GPC-3, GPNMB, GPR20, GZMB, HER2, HER3, HLA-DOB, HMOX1, IFI6, IFNG, IGF-1R, IGFBP3, IL10RA1, IL-13R, IL-2, IL20Ra, IL-3, IL-4, IL-6, IRTA2, KISS1R, KRT33A, LIV-1, LOX, LRP-1, LRRC15, LUM, LY64, LY6E, Ly86, LYPD3, MDP, MMP10, MMP14, MMP16, MPF, MSG783, MSLN, MUC-1, NaPi2b, Napi3b, Nectin-4, NOG, P2X5, pCAD, P-Cadherin, PDGFRA, PDK1, PD-L1, PFKFB3, PGF, PGK1, PIK3AP1, PIK3CD, PLOD2, PSCA, PSCAhlg, PSMA, PTK7, P-Cadherin, RN F43, ROR1, ROR2, SERPINE1, SLC39A6, SLTRK6, STAT1, STEAP1, STEAP2, TCF4, TENB2, TGFB1, TGFB2, TGFBR1, TNFRSF21, TNFSF9, Trop-2, TrpM4, Tyro7, UPK1B, VEGFA, WNT5A, ADAM9, epidermal growth factor, brevican, mesothelin, sodium phosphate cotransporter 2B, Claudin18.2, endothrin receptor, mucins (such as mucin 1 and mucin 16), guanylate cyclase C, integrin α4β7, integrin αvβ6, trophoblast glycoprotein, and tissue factor.

[0485] In this application, the term "antibody or its antigen-binding fragment" generally refers to an immunological binder, which extends to all antibodies from all species, including dimers, trimers and multimer antibodies; bispecific antibodies; chimeric antibodies; fully human antibodies; humanized antibodies; recombinant and reconstructed antibodies and their fragments. The term "antibody or its antigen-binding fragment" can refer to any antibody-like molecule with an antigen-binding region, and the term includes small molecule fragments such as Fab', Fab, F(ab')2, single domain antibodies (DABs), Fv, scFv (single chain Fv), linear antibodies, diabodies, etc. The term "antigen-binding fragment" can refer to one or more fragments of an antibody that retain the ability to specifically bind to an antigen. For example, a fragment of a full-length antibody can be used to implement the antigen-binding function of an antibody. The techniques for preparing and using various antibody-based constructs and fragments are well known in the art. The antibodies may include: anti-HER2 (ErbB2) antibody, anti-EGFR antibody, anti-B7H3 antibody, anti-c-Met antibody, anti-HER3 (ErbB3) antibody, anti-HER4 (ErbB4) antibody, anti-CD20 antibody, anti-CD22 antibody, anti-CD30 antibody, anti-CD33 antibody, anti-CD44 antibody, anti-CD56 antibody, anti-CD70 antibody, anti-CD73 antibody, anti-CD105 antibody, anti-CEA antibody, anti-A33 antibody, anti-Cripto antibody, anti-EphA2 antibody, anti-G250 antibody, anti-MUCl antibody, anti-Lewis Y antibody, anti-TROP2 antibody, anti-Claudin antibody 18.2 antibody, anti-VEGFR antibody, anti-GPNMB antibody, anti-Integrin antibody, anti-PSMA antibody, anti-Tenascin-C antibody, anti-SLC44A4 antibody, anti-ADAM9 antibody, anti-GPC-3 antibody and anti-Mesothelin antibody, such as Patritumab and / or Codrituzumab.

[0486] In this application, the term "chimeric antibody" generally refers to an antibody formed by fusing the variable region of a murine antibody with the constant region of a human antibody, which can reduce the immune response induced by the murine antibody. Methods for creating chimeric antibodies include, for example, establishing a hybridoma that secretes a murine-specific monoclonal antibody, cloning the variable region genes from the murine hybridoma cells, cloning the human antibody constant region genes as needed, and then ligating the murine variable region genes with the human constant region genes to form a chimeric gene, which is then inserted into an expression vector. Chimeric antibody molecules can then be expressed in eukaryotic or prokaryotic systems.

[0487] In this application, the term "humanized antibody", also referred to as CDR-grafted antibody, generally refers to an antibody produced by transplanting mouse CDR sequences into a human antibody variable region framework, i.e., into different types of human germline antibody framework sequences. Humanized antibodies can overcome the problem of chimeric antibodies inducing strong heterologous reactions due to carrying a large amount of mouse protein components. Such framework sequences can be obtained from public DNA databases or published references including germline antibody gene sequences. For example, the germline DNA sequences of human heavy chain variable region and light chain variable region genes can be found in the "VBase" human germline sequence database.

[0488] In this application, the terms "fully human antibody", "human antibody", "fully human antibody" or "completely human antibody" are used interchangeably, and both the variable and constant regions of the antibody may be of human origin, eliminating immunogenicity and toxic side effects.

[0489] The antibodies or ligands described herein may be fully human monoclonal antibodies. Relevant technologies for preparing fully human antibodies may include: human hybridoma technology, EBV-transformed B lymphocyte technology, phage display technology, transgenic mouse antibody preparation technology, and single B cell antibody preparation technology.

[0490] In this application, the term "CDR" generally refers to one of the six hypervariable regions within the variable domain of an antibody that primarily contributes to antigen binding. The most commonly used definitions of the six CDRs are provided, for example, by Kabat EA et al. (1991) Sequences of proteins of immunological interest. NIH Publication 91-3242), Chothia et al., "Canonical Structures For the Hypervariable Regions of Immunoglobulins," J. Mol. Biol. 196: 901 (1987); and MacCallum et al., "Antibody-Antigen Interactions: Contact Analysis and Binding Site Topography," J. Mol. Biol. 262: 732 (1996). As used in this application, the Kabat definition of CDRs can be applied to CDR1, CDR2 and CDR3 of the light chain variable domain (CDRL1, CDRL2, CDRL3 or L1, L2, L3), and CDR1, CDR2 and CDR3 of the heavy chain variable domain (CDR H1, CDRH2, CDRH3 or H1, H2, H3).

[0491] The term "one or more" or the similar expression "at least one" may mean, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more;

[0492] When the lower limit and upper limit of a numerical range are disclosed, any value and any included range falling within the range is specifically disclosed. In particular, every range of values ​​disclosed herein should be understood to mean every value and range encompassed within the broader range;

[0493] For example, the statement "C 1-6 " should be understood to include any sub-ranges therein and each point value, such as C 2-5 、C 3-4 、C 1-2 、C 1-3 、C 1-4 、C 1-5 etc., as well as C1, C2, C3, C4, C5, C6, etc. For example, the expression “C 3-10 ” should also be understood in a similar manner, for example, any sub-ranges and point values ​​contained therein may be included, for example, C 3-9 、C 6-9 、C 6-8 、C6-7 、C 7-10 、C 7-9 、C 7-8 、C 8-9 etc. and C3, C4, C5, C6, C7, C8, C9, C 10 etc. For another example, the expression "3-10 yuan" should be understood to include any sub-ranges and point values ​​therein, such as 3-4 yuan, 3-5 yuan, 3-6 yuan, 3-7 yuan, 3-8 yuan, 3-9 yuan, 4-5 yuan, 4-6 yuan, 4-7 yuan, 4-8 yuan, 5-7 yuan, 5-8 yuan, 6-7 yuan, etc., as well as 3, 4, 5, 6, 7, 8, 9, 10 yuan, etc. For another example, the expression "5-10 yuan" should also be understood in a similar manner, such as it can include any sub-ranges and point values ​​contained therein, such as 5-6 yuan, 5-7 yuan, 5-8 yuan, 5-9 yuan, 5-10 yuan, 6-7 yuan, 6-8 yuan, 6-9 yuan, 6-10 yuan, 7-8 yuan, etc., as well as 5, 6, 7, 8, 9, 10 yuan, etc.

[0494] In the present application, the term "natural number" is, for example, 0-50, 0-40, 0-30, 0-20, 0-10, 0-8, 0-6, 0-6, 0-4 or 0-2; or 0, 1, 2, 3, 4, 5, 6, 7 or 8.

[0495] In this application, the term "alkyl" refers to a saturated straight or branched hydrocarbon group. 1-6 "Alkyl" refers to a saturated straight or branched chain hydrocarbon group having 1 to 6 carbon atoms (e.g., 1, 2, 3, 4, 5 or 6 carbon atoms). 1-6 The term "alkyl" refers to methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl or n-hexyl.

[0496] In this application, the term "C 0-6 In the "alkylene group", when it is 0, the C0 alkylene group is a connecting bond.

[0497] In this application, the term "C 0-6 When C0 alkyl is 0, it is hydrogen.

[0498] In this application, the term "alkylene" refers to a saturated straight-chain or branched divalent hydrocarbon group. For example, the term "C 1-6 "Alkylene" refers to a saturated straight or branched divalent hydrocarbon group having 1 to 6 carbon atoms. 1-6 Examples of "alkylene" include, but are not limited to, methylene, ethylene, propylene, or butylene.

[0499] In this application, the term "alkenyl" refers to a straight or branched aliphatic hydrocarbon group having one or more carbon-carbon double bonds. 2-6 The term "alkenyl" refers to an alkenyl group having 2 to 6 carbon atoms and one, two or three (preferably one) carbon-carbon double bonds (e.g., ethenyl, 1-propenyl, 2-propenyl, 2-butenyl, 3-butenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, 2-methyl-2-propenyl, 4-methyl-3-pentenyl, etc.).

[0500] In this application, the term "alkynyl" refers to a straight-chain or branched aliphatic hydrocarbon group having one or more carbon-carbon triple bonds. 2-6 The term "alkynyl" refers to an alkynyl group having 2 to 6 carbon atoms and one, two or three (preferably one) carbon-carbon triple bonds (e.g., ethynyl, 1-propynyl, 2-propynyl, 2-butynyl, 3-butynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl, etc.).

[0501] In this application, the term "aryl" refers to a monocyclic or condensed aromatic hydrocarbon group having a conjugated π electron system. For example, the term "C 6-10 The term "aryl" refers to an aromatic group having 6 to 10 carbon atoms (e.g., phenyl, naphthyl, etc.).

[0502] As used herein, the term "heteroaryl" or "heteroaromatic ring" refers to a monocyclic or fused heterocyclic ring system having one or more conjugated π-electron systems, wherein one or more (e.g., 1, 2, or 3) ring atoms are heteroatoms selected from N, O, P, and S, and the remaining ring atoms are C. A heteroaryl group or heteroaromatic ring can be characterized by the number of ring atoms (e.g., 5-10 members, 5-6 members). For example, a 5-12 membered heteroaryl group can contain 5-12 (e.g., 5, 6, 7, 8, 9, 10, 11, or 12) ring atoms, particularly 5, 6, 9, or 10 ring atoms. Examples of heteroaryl groups include thienyl, furanyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, pyridinyl, pyrazinyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, indolyl, and the like.

[0503] In the present application, the term "cycloalkyl" refers to a saturated or partially saturated, monocyclic or polycyclic (such as bicyclic) non-aromatic hydrocarbon group. 3-12 Cycloalkyl, C 3-6 Cycloalkyl. For example, "C 3-12"Cycloalkyl" or "3-12 membered cycloalkyl" refers to a cycloalkyl group having 3-12 ring carbon atoms (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12). Common cycloalkyl groups include, but are not limited to, monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclobutene, cyclopentene, cyclohexene, etc.; or bicyclic cycloalkyl groups, including fused rings, bridged rings or spiro rings, such as bicyclo[1.1.1]pentyl, bicyclo[2.2.1]heptyl, bicyclo[3.2.1]octyl, bicyclo[5.2.0]nonyl, decahydronaphthyl, etc.

[0504] In the present application, the term "cycloalkylene" refers to a saturated or partially saturated, monocyclic or polycyclic (such as bicyclic) non-aromatic divalent cyclic group. 3-12 Cycloalkylene, C 3-6 Cycloalkylene. For example, "C 3-12 "Cycloalkylene" or "3-12 membered cycloalkylene" refers to a cycloalkylene group having 3-12 ring carbon atoms (e.g., 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12). Common cycloalkylene groups include, but are not limited to, monocyclic cycloalkylene groups such as cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, cyclobutene, cyclopentene, cyclohexene, etc.; or bicyclic cycloalkylene groups including fused, bridged or spiro rings such as bicyclo[1.1.1]pentylene, bicyclo[2.2.1]heptylene, bicyclo[3.2.1]octylene, bicyclo[5.2.0]nonylene, decahydronaphthylene, etc.

[0505] The term "heterocycloalkyl" refers to a saturated or partially saturated non-aromatic cyclic group containing at least one heteroatom selected from N, O, P, and S. Preferably, the number of heteroatoms is 1, 2, 3, or 4. Examples include 4- to 12-membered, 4- to 6-membered, 5- to 12-membered, 5- to 8-membered, 5- to 6-membered, 9- to 10-membered, 11- to 12-membered, 3- to 8-membered, and 3- to 6-membered heterocycloalkyl groups. Specific examples include, but are not limited to, oxiranyl, oxocyclobutane, pyrrolidinyl, tetrahydrofuranyl, piperidinyl, piperazinyl, tetrahydropyranyl, and homopiperazinyl.

[0506] The term "heterocycloalkylene" refers to a saturated or partially saturated, non-aromatic, divalent cyclic group containing at least one ring member selected from N, O, P, and S, wherein the number of heteroatoms is preferably 1, 2, 3, or 4. Examples include 3-8 membered and 3-6 membered heterocycloalkylene groups. Specific examples include, but are not limited to, oxiranylene, oxocyclobutanylene, pyrrolidinylene, tetrahydrofuranylene, piperidinylene, piperazinylene, tetrahydropyranylene, and homopiperazinylene.

[0507] The term "fused ring (fused ring system)" refers to a chemically feasible polycyclic structure formed by two or more (e.g., 3, 4, or 5) carbocyclic or heterocyclic rings with shared ring edges or shared atoms, wherein the carbocyclic ring includes a cycloalkyl group and an aryl group, and the heterocyclic ring includes a heteroaromatic ring and a heterocycloalkyl group. The fused ring system includes, but is not limited to, a fused ring system formed by a cycloalkyl group and a cycloalkyl group, a fused ring system formed by a cycloalkyl group and a heterocycloalkyl group, a fused ring system formed by a cycloalkyl group and an aromatic ring, a fused ring system formed by a cycloalkyl group and a heteroaromatic ring, a fused ring system formed by a heterocycloalkyl group and a heteroaromatic ring, a fused ring system formed by a heterocycloalkyl group and an aromatic ring, a fused ring system formed by a heteroaromatic ring and a heteroaromatic ring, a fused ring system formed by a heteroaromatic ring and an aromatic ring, and the like.

[0508] In this application, the term "halogen" generally refers to fluorine, chlorine, bromine, iodine, for example fluorine, chlorine.

[0509] In this application, the term "each independently" means that at least two groups (or fragments) present in a structure with the same or similar value ranges can have the same or different meanings in specific circumstances. For example, if substituent X and substituent Y are each independently hydrogen, halogen, hydroxyl, cyano, alkyl, or aryl, then when substituent X is hydrogen, substituent Y can be either hydrogen, or halogen, hydroxyl, cyano, alkyl, or aryl; similarly, when substituent Y is hydrogen, substituent X can be either hydrogen, or halogen, hydroxyl, cyano, alkyl, or aryl.

[0510] In this application, the term "optional" or "optionally" generally means that the subsequently described event or circumstance can but need not occur, and the description includes instances where the event or circumstance occurs or does not occur. For example, "a heterocyclic group optionally substituted with an alkyl group" means that the alkyl group can but need not be present, and the description includes instances where the heterocyclic group is substituted with an alkyl group and instances where the heterocyclic group is not substituted with an alkyl group.

[0511] In the present application, the term "substituted" and its other variant forms in this article refer to that one or more (such as 1, 2, 3 or 4) atoms or atomic groups (such as hydrogen atoms) on the specified atom are replaced by other equivalents, provided that the normal valence of the specified atom or atomic group in the current situation is not exceeded, and a stable compound can be formed. If a certain atom or atomic group is described as "optionally substituted by ... ", it can be substituted or unsubstituted. Unless otherwise indicated, the attachment site of a substituent herein can be from any suitable position of a substituent. When the link in a substituent is shown as a chemical bond between two atoms connected to each other in a ring system, it means that the substituent can be connected to any ring-forming atom in the ring system.

[0512] This article uses wavy lines The bonds in the structural formulae represented are intended to indicate that the structure represents either a cis or trans isomer, or a mixture of cis and trans isomers in any ratio.

[0513] The term "oxo," as used herein alone or in combination with other groups, refers to =0.

[0514] In the present application, one or more hydrogen atoms in a group, for example up to 5, for example 1 to 3 hydrogen atoms, are independently replaced by a corresponding number of substituents. The substituents are only in their possible chemical positions, and those skilled in the art can determine (by experiment or theory) whether substitution is possible or not without undue effort. For example, an amino or hydroxyl group with free hydrogen may be unstable when combined with a carbon atom with an unsaturated (e.g., olefinic) bond.

[0515] In this application, the term "amino acid" includes natural amino acids and non-natural amino acids, and the writing of conventional amino acids follows conventional usage. See, for example, Immunology-A Synthesis (2nd Edition, ES Golub and DRGren, Eds., Sinauer Associates, Sunderland, Mass. (1991)), which is incorporated herein by reference. In this article, the terms "polypeptide" and "protein" have the same meaning and are used interchangeably. And in this application, amino acids are generally represented by single-letter and three-letter abbreviations known in the art. For example, alanine can be represented by A or Ala; arginine can be represented by R or Arg; glycine can be represented by G or Gly; glutamine can be represented by Q or Gln;

[0516] As used herein, the term "unnatural amino acid" has the following structure: wherein r is selected from 0, 1, 2, 3, 4 and 5; wherein R a 、R b Each independently selected from -C 1-6 Alkylene-NH2, -C 1-6 Alkylene-NH-C 1-6 Alkyl, -C 1-6 Alkylene-N(C 1-6 Alkyl)2, -C 1-6 Alkylene-NH-C 3-10 Cycloalkyl, -C 1-6 Alkylene-N(3-10 membered cycloalkyl)(C 1-6 Alkyl), -C 1-6 Alkylene-C 3-10 Cycloalkyl, -C 1-6 Alkylene-(3-10 membered heterocycloalkyl), -C 1-6Alkylene-NHCOC 1-6 Alkyl, -C 1-6 Alkylene-NHCOOC 1-6 Alkyl, -C 1- 6-Alkylene-NHS(O)2C 1-6 Alkyl, -C 1-6 Alkylene-S(O)2-C 1-6 Alkyl, -C 1-6 Alkylene-S(O)2-C 3-10 Cycloalkyl, -C 1-6 Alkylene-S(O)2-NH2, -C 1-6 Alkylene-COOH, -C 1-6 Alkylene-CONH2, -C 1-6 Alkylene-CONHC 1-6 Alkyl, -C 1-6 Alkylene-CO (3-10 membered heterocycloalkyl), The alkyl, alkylene, cycloalkyl, and heterocycloalkyl groups are each independently optionally substituted by one or more substituents selected from H, halogen, -OH, -NH2, -SH, -NO2, CN, -COOH, and oxo; or any R a 、R b Together with the atoms to which it is attached, it forms a 3-10 membered heterocycloalkyl or a 3-10 membered cycloalkyl; each of the cycloalkyl and heterocycloalkyl groups is optionally substituted with one or more substituents selected from H, halogen, -OH, -NH2, -SH, -NO2, CN, -COOH and oxo;

[0517] In this application, the term "compound" generally refers to a substance having two or more different elements. For example, the compound of the present application can be an organic compound, for example, the compound of the present application can be a compound with a molecular weight of 500 Daltons or less, a compound with a molecular weight of 1000 Daltons or less, a compound with a molecular weight of 1000 Daltons or more, or a compound with a molecular weight of 1000 Daltons or more, or a compound with a molecular weight of 10000 Daltons or more, or a compound with a molecular weight of 100000 Daltons or more. In this application, a compound can also refer to a compound connected by chemical bonds, for example, a compound in which one or more molecules with a molecular weight of 1000 Daltons or less are connected to a biomacromolecule by chemical bonds, and the biomacromolecule can be a polysaccharide, protein, nucleic acid, polypeptide, etc. For example, the compound of the present application can include a compound in which a protein is connected to one or more molecules with a molecular weight of 1000 Daltons or less, a compound in which a protein is connected to one or more molecules with a molecular weight of 10000 Daltons or less, or a compound in which a protein is connected to one or more molecules with a molecular weight of 100000 Daltons or less.

[0518] In this application, the term "stereoisomer" refers to an isomer formed by at least one asymmetric center. In compounds with one or more (e.g., one, two, three, or four) asymmetric centers, racemic mixtures, single enantiomers, diastereomeric mixtures, and individual diastereomers can be produced. Specific individual molecules can also exist as geometric isomers (cis / trans). Similarly, the compounds of the present invention can exist as mixtures of two or more structurally different forms in rapid equilibrium (commonly referred to as tautomers). Representative examples of tautomers include keto-enol tautomers, phenol-ketone tautomers, nitroso-oxime tautomers, imine-enamine tautomers, etc. It is to be understood that the scope of this application encompasses all such isomers or mixtures thereof in any proportion (e.g., 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99%).

[0519] In this article, solid lines can be used Solid wedge or virtual wedge The carbon-carbon bonds of the compounds of the present invention are depicted. The use of solid lines to depict bonds to asymmetric carbon atoms is intended to indicate that all possible stereoisomers at that carbon atom are included (e.g., specific enantiomers, racemic mixtures, etc.). The use of solid or dashed wedges to depict bonds to asymmetric carbon atoms is intended to indicate that the indicated stereoisomers exist. When present in a racemic mixture, solid and dashed wedges are used to define relative stereochemistry, not absolute stereochemistry. Unless otherwise indicated, the compounds of the present invention are intended to exist as stereoisomers, including cis and trans isomers, optical isomers (e.g., R and S enantiomers), diastereomers, geometric isomers, rotational isomers, conformational isomers, atropisomers, and mixtures thereof. The compounds of the present invention may exhibit more than one type of isomerism and consist of mixtures thereof (e.g., racemic mixtures and diastereomeric pairs).

[0520] It will be understood by those skilled in the art that the structural formulas used in the present invention to describe groups are based on the conventions used in the art. This means that the corresponding group R is connected to other fragments or groups in the compound through this site. A "-" at the end of a group indicates that the group is connected to another fragment in the molecule through this site. For example, CH3-C(=O)- means that the C(=O) in the acetyl group is connected to another fragment in the molecule.

[0521] In this application, the term "comprising" generally refers to including the features specified but not excluding other elements. The terms "above" and "below" generally refer to including the number.

[0522] Unless otherwise indicated, the structures described herein may also include compounds that differ only in the presence or absence of one or more isotopically enriched atoms. For example, compounds identical to the structures described herein except for the replacement of a hydrogen atom by deuterium or tritium, or the replacement of a carbon atom by carbon-13 or carbon-14, are within the scope of this application.

[0523] The terms "active ingredient," "therapeutic agent," "active substance," or "active agent" refer to a chemical entity that is effective in treating one or more symptoms of a target disorder or condition.

[0524] As used herein, unless otherwise indicated, the terms "treat," ...

[0525] As used herein, "subject" includes humans and non-human animals. Exemplary human subjects include human subjects suffering from diseases (e.g., the diseases described herein) (referred to as patients) or normal individuals. "Non-human animals" herein include all vertebrates, such as non-mammals (e.g., birds, amphibians, reptiles) and mammals, such as non-human primates, livestock and / or domesticated animals (e.g., sheep, dogs, cats, cows, pigs, etc.).

[0526] Those skilled in the art will appreciate that, since nitrogen requires an available lone pair of electrons to be oxidized to oxides, not all nitrogen-containing heterocycles can form nitrogen oxides. Those skilled in the art will recognize nitrogen-containing heterocycles that can form nitrogen oxides. Those skilled in the art will also recognize that tertiary amines can form nitrogen oxides. Synthetic methods for preparing nitrogen oxides of heterocycles and tertiary amines are well known to those skilled in the art and include oxidizing heterocycles and tertiary amines with peroxyacids such as Peracetic Acid and Metachloroperbenzoic Acid (m-CPBA), hydrogen peroxide, alkyl hydroperoxides such as tert-butyl hydroperoxide, sodium perborate, and dioxirane such as dimethyldioxirane. These methods for preparing nitrogen oxides have been extensively described and reviewed in the literature, see for example: TL Gilchrist, Comprehensive Organic Synthesis, vol. 7, pp 748-750 (AR Katritzky and AJ Boulton, Eds., Academic Press); and GWH Cheeseman and ESGWerstiuk, Advances in Heterocyclic Chemistry, vol. 22, pp 390-392 (AR Katritzky and AJ Boulton, Eds., Academic Press).

[0527] Those skilled in the art will understand that the compounds covered by the present invention are all chemically feasible compounds; and all chemical bonds are connected in chemically feasible ways.

[0528] The present invention also encompasses compounds of the present invention that contain protecting groups. During any process for preparing the compounds of the present invention, it may be necessary and / or desirable to protect sensitive or reactive groups on any of the molecules involved, thereby forming a chemically protected form of the compounds of the present invention. This can be achieved using conventional protecting groups, for example, those described in TW Greene & P.G.M. Wuts, Protective Groups in Organic Synthesis, John Wiley & Sons, 2006, which references are incorporated herein by reference. Protecting groups can be removed at an appropriate subsequent stage using methods known in the art.

[0529] The present invention also encompasses methods for preparing the compounds described herein. It should be understood that the compounds of the present invention can be synthesized using the methods described below, as well as synthetic methods known in the art of synthetic organic chemistry or variations thereof known to those skilled in the art. Preferred methods include, but are not limited to, those described below. The reaction can be carried out in a solvent or solvent mixture that is appropriate for the reagents and materials used and suitable for the transformation to be achieved.

[0530] Without violating the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain preferred embodiments of the present invention.

[0531] The reagents and raw materials used in the present invention are commercially available.

[0532] The positive progress of the present invention is that the compounds of the present invention have one or more of the following advantages:

[0533] (1) It has inhibitory activity on the proliferation of tumor cells in vitro;

[0534] (2) Having plasma stability;

[0535] (3) Has tumor-suppressing effect in vivo;

[0536] (4) possessing anti-transporter transport capability;

[0537] (5) Possesses the ability to target tumors in vivo;

[0538] (6) Good in vivo safety;

[0539] In addition, the coupling method disclosed herein has a wide range of applications and can be widely used for coupling with bioactive molecules such as antibodies or targeted small molecule ligands. In summary, the protein degraders, linkers, antibodies and ADCs of the present invention have significant clinical value. DETAILED DESCRIPTION

[0540] The present invention includes all combinations of the described specific embodiments. Further embodiments of the present invention and the full scope of applicability will become apparent from the detailed description provided below. However, it should be understood that although the detailed description and specific examples indicate preferred embodiments of the present invention, these descriptions and examples are provided by way of illustration only, because various changes and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art from this detailed description. For all purposes, all publications, patents and patent applications cited herein, including citations, will be incorporated herein by reference in their entirety. The present invention is further illustrated below by way of example, but the present invention is not limited to the scope of the described embodiments. The experimental methods for which specific conditions are not specified in the following examples are selected according to conventional methods and conditions, or according to the product specifications.

[0541] Mass spectrometry (MS) was measured using an Agilent (ESI) mass spectrometer, manufactured by Agilent, model: Agilent 6120B.

[0542] Preparative high performance liquid chromatography (HPLC) was performed using a Shimadzu LC-8A preparative liquid chromatograph (YMC, ODS, 250 × 20 mm column).

[0543] Thin layer chromatography purification was performed using GF 254 (0.4-0.5 nm) silica gel plates produced in Yantai.

[0544] The reaction is monitored by thin layer chromatography (TLC) or liquid chromatography-mass spectrometry (LC-MS). The developing solvent systems used include, but are not limited to, dichloromethane and methanol systems, n-hexane and ethyl acetate systems, and petroleum ether and ethyl acetate systems. The volume ratio of the solvents is adjusted according to the polarity of the compounds or by adding triethylamine.

[0545] Column chromatography generally uses Qingdao Ocean 200-300 mesh silica gel as the stationary phase. Eluent systems include, but are not limited to, dichloromethane and methanol systems and n-hexane and ethyl acetate systems. The volume ratio of the solvents is adjusted according to the polarity of the compound, and a small amount of triethylamine can also be added for adjustment.

[0546] Unless otherwise specified in the examples, the reaction temperature is room temperature (20°C to 30°C).

[0547] Unless otherwise specified, the reagents used in the examples were purchased from Acros Organics, Aldrich Chemical Company, Nanjing Yaoshi Technology, or Shanghai Shuya Pharmaceutical Technology.

[0548] The above embodiments do not limit the solutions of the present application in any way. In addition to those described herein, various modifications of the present invention will be apparent to those skilled in the art based on the foregoing description. Such modifications are also intended to fall within the scope of the appended claims. Each reference cited in this application (including all patents, patent applications, journal articles, books and any other disclosures) is incorporated by reference in its entirety.

[0549] In conventional synthesis methods, preparation examples, embodiments and intermediate synthesis examples, the meanings of the abbreviations are shown in the following table.

[0550] Synthesis of starting materials:

[0551] Preparation Example 1.1: Preparation of Compound S1

[0552] Step 1: Synthesis of compound S1-2

[0553] Compound S1-1 (3.00 g, 12.73 mmol) and potassium carbonate (3.52 g, 25.46 mmol) were added to DMF (30 mL) and stirred for 1 hour. 2-Chloro-N-methylacetamide (2.05 g, 19.10 mmol) was then added and allowed to react overnight at room temperature. After TLC analysis, aqueous solution and ethyl acetate were added, stirred, and the layers separated. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography to yield compound S1-2 (2.73 g, 70% yield).

[0554] Step 2: Synthesis of Compound S1-3

[0555] At room temperature, compound S1-2 (2.53 g, 8.24 mmol) was dissolved in anhydrous THF (25 mL), cooled to 0°C, and a 2M borane solution in tetrahydrofuran (22 mL, 44.55 mmol) was added. The temperature was then raised to 70°C and allowed to react overnight. LCMS confirmed the reaction was complete, and the temperature was lowered to 0°C. Methanol was slowly added dropwise to quench the reaction, followed by concentration under reduced pressure. 2M aqueous hydrochloric acid was added to the residue and stirred for 2 h. Methyl tert-butyl ether was then added, stirred, and the mixture was separated, with the aqueous phase retained. The pH of the aqueous phase was adjusted to 9 with saturated sodium bicarbonate, and the aqueous phase was extracted with ethyl acetate. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to obtain compound S1-3 (2.22 g, 92% yield).

[0556] Step 3: Synthesis of Compound S1-4

[0557] Compound S1-3 (2.61 g, 8.91 mmol) and triethylamine (2.70 g, 26.73 mmol) were dissolved in THF (25 mL) at room temperature. (Boc)2O (2.14 g, 9.80 mmol) was added and stirred at room temperature for 2 h. TLC indicated the reaction was complete. The mixture was concentrated under reduced pressure, and the residue was purified by column chromatography to afford compound S1-4 (3.15 g, 90% yield).

[0558] Step 4: Synthesis of compound S1-5

[0559] Compound S1-4 (3.15 g, 8.02 mmol), zinc cyanide (1.04 g, 8.82 mmol), and PdCl2(PPh3)2 (0.56 g, 0.80 mmol) were dissolved in dioxane (25 mL) at room temperature and heated to 80°C under nitrogen for 6 h. LCMS indicated the reaction was complete. The product was concentrated under reduced pressure, and the residue was purified by column chromatography to afford compound S1-5 (2.18 g, 80% yield).

[0560] Step 5: Synthesis of compound S1

[0561] Compound S1-5 (2.18 g, 6.42 mmol) was dissolved in THF (20 mL) at room temperature, and cobalt chloride (0.83 g, 6.43 mmol) in water (10 mL) was added and stirred thoroughly. Sodium borohydride (0.49 g, 12.86 mmol) was then added, and the reaction mixture was heated to 35°C for 12 h. LCMS indicated the reaction was complete. Water and ethyl acetate were added to the reaction mixture, stirred, and separated. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure to yield compound S1 (0.88 g, 40% yield).

[0562] Preparation Example 1.2: Preparation of Compound S2

[0563] Step 1: Synthesis of compound S2-2

[0564] Compound S2-1 (2.20 g, 10.00 mmol) and triethylamine (3.04 g, 30.00 mmol) were dissolved in THF (30 mL). (Boc)2O (2.62 g, 12 mmol) was added and stirred at room temperature for 2 h. TLC indicated the reaction was complete. The mixture was concentrated under reduced pressure, and the residue was purified by column chromatography to afford compound S2-2 (3 g, 94% yield).

[0565] Step 2: Synthesis of compound S2-3.

[0566] Compound S2-2 (1.00 g, 3.12 mmol), p-nitrothiophenol (0.58 g, 3.74 mmol), potassium carbonate (0.86 g, 6.24 mmol), and copper powder (0.59 g, 9.36 mmol) were added to DMF (10 mL) and heated to 140°C under nitrogen for 5 h. After cooling to room temperature, the mixture was filtered, and the filtrate was added with ethyl acetate and water. After stirring, the layers were separated. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography to afford compound S2-3 (0.37 g, 30% yield).

[0567] Step 2: Synthesis of compound S2.

[0568] Compound S2-3 (0.37 g, 0.93 mmol) was dissolved in dichloromethane (5 mL), followed by the addition of trifluoroacetic acid (1 mL) and allowed to react at room temperature for 30 min. TLC confirmed the reaction was complete, and the solvent was removed by concentration under reduced pressure. Dichloromethane was then added, and the pH was adjusted to 8 with saturated sodium bicarbonate. The layers were separated, and the organic phase was concentrated to dryness to afford compound S2 (0.21 g, 73% yield).

[0569] Preparation Example 1.3: Preparation of Compound S3

[0570] Step 1: Synthesis of compound S3-2

[0571] To a solution of compound S3-1 (2 g, 13.02 mmol) in DMF (30 mL) was added CsCO (4.6 g, 14.32 mmol), followed by p-nitrofluorobenzene (1.9 g, 13.67 mmol). The mixture was stirred at 120°C for 1 hour, then cooled to room temperature. Water and ethyl acetate were added, stirred, and the layers separated. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography to afford compound S3-2 (2.5 g, 72% yield).

[0572] Step 2: Synthesis of compound S3-3.

[0573] To a solution of compound S3-2 (2 g, 7.28 mmol) in EtOH / H₂O (15 mL / 2 mL) was added Fe powder (3 g, 54.6 mmol), followed by NH₄Cl (3 g, 54.6 mmol). The mixture was stirred at 80°C for 2 hours. After completion of the reaction, the mixture was cooled to room temperature and diluted with acetonitrile. The mixture was filtered and concentrated under reduced pressure to afford crude compound S3-3 (1.75 g).

[0574] Step 3: Synthesis of compound S3-4.

[0575] Compound S3-3 (1.50 g, 6.13 mmol) and NaHCO (1.00 g, 12.26 mmol) were added to a mixture of CHCNCN / HO (15 mL / 10 mL), and BocO (2.61 g, 9.20 mmol) was added with stirring. The mixture was stirred at room temperature for 24 hours, followed by the addition of water and ethyl acetate. After stirring, the layers were separated. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography to afford compound S3-4 (1.31 g, 72% yield).

[0576] Step 4: Synthesis of compound S3.

[0577] To a solution of LiAlH4 (132 mg, 3.48 mmol) in THF (6 mL) was added dropwise a solution of S3-4 (0.6 g, 1.74 mmol) in THF (6 mL) at 0°C. The mixture was stirred at 0°C for 0.5 h, followed by the addition of sodium sulfate decahydrate (500 mg). The filtered solution was concentrated under reduced pressure, and the residue was purified by column chromatography to afford compound S3 (0.3 g, 50% yield).

[0578] Preparation Example 1.4: Preparation of Compound S4

[0579] Step 1: Synthesis of compound S4-3

[0580] Under nitrogen, sodium hydride (0.42 g, 17.33 mmol) was added to a solution of S4-2 (2 g, 11.55 mmol) in anhydrous DMF (10 mL) at 0°C. After stirring for 0.5 hours, compound S4-2 (1.79 g, 11.55 mmol) was added to the reaction mixture. After the addition was complete, the temperature was slowly raised to room temperature and the reaction was continued for 1 hour. Ice water and ethyl acetate were then added, stirred, and the layers separated. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography to afford compound S4-3 (1.78 g, 50% yield).

[0581] Step 2: Synthesis of compound S4-4

[0582] Compound S4-4 was synthesized by referring to the method of step 4 of Preparation Example 1.3.

[0583] Example 1: Linker 1 ) Preparation of intermediates

[0584] Example 1.1: Preparation of intermediate INT1

[0585] Step 1: Preparation of compound INT1-3

[0586] Compound INT1-1 (5.00 g, 29.38 mmol) was dissolved in DMF (50 mL) at room temperature, and HATU (16.76 g, 44.07 mmol) and DIEA (11.39 g, 88.14 mmol) were added. After stirring at room temperature for 1 hour, compound INT1-2 (3.85 g, 29.38 mmol) was added, and the reaction was continued for 2 hours. Upon completion of the reaction by LCMS, ethyl acetate and water were added, and the pH was adjusted to approximately 6 with 2M citric acid while stirring. The liquids were separated, and the organic phase was washed twice with saturated brine, dried, concentrated, and purified by column chromatography to obtain compound INT1-3 (4.58 g, 55% yield).

[0587] Step 2: Preparation of compound INT1-5

[0588] Compound INT1-3 (2 g, 7.06 mmol) was dissolved in DMF (20 mL) at room temperature, and HATU (4.03 g, 10.59 mmol) and DIEA (2.73 g, 21.18 mmol) were added. After stirring at room temperature for 40 min, compound INT1-4 (1.84 g, 7.06 mmol) was added, and the reaction was continued overnight. Upon completion of the reaction by LCMS, ethyl acetate and water were added, and the pH was adjusted to approximately 6 with 2 M citric acid while stirring. The layers were separated, and the organic phase was washed twice with saturated brine, dried, concentrated, and purified by column chromatography to obtain compound INT1-5 (2.23 g, 60% yield).

[0589] Step 3: Preparation of compound INT1

[0590] Compound INT1-5 (0.50 g, 0.95 mmol) was dissolved in anhydrous dichloromethane (10 mL) at room temperature, and m-CPBA (0.49 g, 2.85 mmol) was added. The mixture was stirred at room temperature for 4 h. LCMS confirmed the reaction was complete, and the reaction mixture was filtered to obtain the filter cake, yielding compound INT1 (0.16 g, 30% yield).

[0591] Example 1.2: Preparation of intermediate INT2

[0592] Compounds INT2-1 (1.00 g, 3.24 mmol) and INT1-4 (0.84 g, 3.24 mmol) were dissolved in DMF (10 mL), followed by the addition of triethylamine (0.66 g, 6.48 mmol) and stirring at room temperature overnight. After TLC, the reaction was complete, and ethyl acetate and water were added. With stirring, the pH was adjusted to approximately 6 with 2M citric acid. The layers were separated, and the organic phase was washed twice with saturated brine, dried, concentrated, and purified by column chromatography to afford compound INT2 (1.18 g, 80% yield).

[0593] Example 1.3: Preparation of intermediate INT3

[0594] Step 1: Synthesis of compound INT3-1

[0595] Compound INT2 (0.50 g, 1.10 mmol) and p-hydroxybenzylamine (0.27 g, 2.20 mmol) were dissolved in dichloromethane / methanol (15 mL, dichloromethane:methanol = 2:1). EEDQ (0.54 g, 2.20 mmol) was added in the dark, and the mixture was incubated at room temperature for 30 h in the dark. After completion of the reaction by TLC, the solvent was removed by concentration under reduced pressure, and the residue was purified by column chromatography to afford compound INT3-1 (0.49 g, 80% yield).

[0596] Step 2: Synthesis of compound INT3

[0597] Compound INT3-1 (0.49 g, 0.88 mmol) and di(p-nitrobenzene) carbonate (0.53 g, 1.75 mmol) were dissolved in anhydrous DMF (10 mL). DIPEA (0.23 g, 1.75 mmol) was then added and stirred at room temperature for 2 hours. After completion of the reaction by TLC, ethyl acetate and water were added, and the mixture was separated by stirring. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. Purification by column chromatography afforded compound INT3 (0.45 g, 70% yield).

[0598] Example 1.4: Preparation of intermediate INT4

[0599] Step 1: Synthesis of compound INT4-2

[0600] Compound INT4-1 (0.50 g, 1.42 mmol) was dissolved in DMF (5 mL), and HATU (0.81 g, 2.13 mmol) and DIEA (0.55 g, 4.26 mmol) were added. After stirring at room temperature for 30 minutes, compound INT1-4 (0.37 g, 1.42 mmol) was added, and the reaction was continued for 2 hours. After the reaction was completed, ethyl acetate was added, and the pH was adjusted to approximately 6 with 2M citric acid while stirring. The layers were separated, and the organic phase was washed twice with saturated brine, dried, concentrated, and purified by reverse-phase HPLC to obtain compound INT4-2 (0.42 g, 50% yield).

[0601] Step 2 to Step 3: Synthesis of Compound INT4

[0602] Compound INT4 was synthesized by a method similar to steps 1 and 2 of Example 1.3.

[0603] Example 2: Preparation of protein degradation agent compounds

[0604] Example 2.1: Preparation of Compound PA1

[0605] Step 1: Synthesis of compound PA1-2

[0606] Triphosgene (0.30 g, 1.00 mmol) was dissolved in anhydrous DCM (3 mL), cooled to 0°C, and triethylamine (0.20 g, 2.00 mmol) was added dropwise while maintaining the temperature. A solution of 1-(4-methyl-3-nitrophenyl)methanamine (0.17 g, 1.00 mmol) in anhydrous DCM (3 mL) was then added dropwise. The temperature was maintained for 1 h. The solvent was removed by concentration under reduced pressure, and the residue was cooled to 0°C. Anhydrous DCM (3 mL) was added again and stirred until uniform. A solution of compound PA1-1 (0.26 g, 1.00 mmol) in anhydrous DMF (3 mL) was then added dropwise. After the addition was complete, the mixture was allowed to warm to room temperature and allowed to react for 1 h. The reaction solution was concentrated under reduced pressure, and DCM and water were added to the residue. After stirring, the mixture was separated. The organic phase was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by column chromatography to obtain compound PA1-2 (0.14 g, 31% yield).

[0607] Step 2: Synthesis of compound PA1

[0608] Compound PA1-2 (0.14 g, 0.31 mmol) was dissolved in DMF (5 mL) and 10% Pd / C (0.02 g) was added. The mixture was then replaced with hydrogen three times and allowed to react under hydrogen for 24 hours. TLC confirmed the reaction was complete. The palladium on carbon was removed by filtration, and the filtrate was concentrated under reduced pressure to remove DMF. The residue was purified by reverse-phase HPLC to afford compound PA1 (32 mg, 32% yield).

[0609] MS m / z(ESI):422.2[M+H] + .

[0610] 1 H NMR (400MHz, DMSO-d6) δ10.97(s,1H),9.27(s,1H),7.78(d,J=1.8Hz,1H),7.58(d,J=7. 8Hz,1H),7.42(dd,J=7.8,1.8Hz,1H),7.26–7.17(m,2H),7.12(d,J=7.8Hz,1H),6.94(t, J=6.0Hz,1H),5.07(dd,J=13.2,5.0Hz,1H),4.38(d,J=17.2Hz,1H),4.31–4.22(m,3H),2 .95–2.86(m,1H),2.61–2.26(m,1H),2.44–2.29(m,1H),2.26(s,3H),2.00–1.96(m,1H).

[0611] Example 2.2: Preparation of compound PA23

[0612] Step 1: Synthesis of compound PA23

[0613] Compound PA23-1 was synthesized by a method similar to that described in step 1 of Example 2.1.

[0614] Step 2: Synthesis of compound PA23

[0615] Compound PA23-1 (0.20 g, 0.32 mmol) was dissolved in dichloromethane (5 mL), followed by the addition of trifluoroacetic acid (1 mL) and allowed to react at room temperature for 30 min. TLC confirmed the reaction was complete, and the solvent was removed by concentration under reduced pressure. Dichloromethane was then added, and the pH was adjusted to 8 with saturated sodium bicarbonate. The layers were separated, and the organic phase was concentrated to dryness. The residue was purified by reverse-phase HPLC to afford compound PA23 (0.06 g, 36% yield).

[0616] MS m / z(ESI):528.2[M+H] + .

[0617] 1 H NMR (400MHz, DMSO-d6) δ9.72(s,1H),8.39(s,1H),7.81(s,1H),7.56(d,J=7.8Hz,2H),7.41–7.22(m,4H),5.06(dd,J=13.2,5.0 Hz,1H),4.46–4.18(m,4H),3.59(d,J=16.2Hz,4H),3.01–2.79(m,5H),2.70–2.55(m,2H),2.45–2.32(m,3H),2.06–1.90(m,1H).

[0618] Example 2.3: Preparation of Compound PB11

[0619] Compound PB11 was synthesized by a similar method to Example 2.1.

[0620] MS m / z(ESI):550.1[M+H] + .

[0621] 1 H NMR(400MHz,DMSO-d6)δ10.97(s,1H),8.84(s,1H),7.68(d,J=8.2Hz,1H), 7.49(s,1H),7.44–7.40(m,2H),7.19–7.17(m,2H),6.84(s,1H),6.81–6.7 7(m,1H),6.64–6.77(m,2H),5.04(dd,J=13.2,5.2Hz,1H),4.39-4.18(m,4 H),2.92–2.84(m,1H),2.57(m,1H),2.38–2.27(m,1H),2.01–1.90(m,1H).

[0622] Example 2.4: Preparation of Compound PB7

[0623] Compound PB7 was synthesized by a similar method as described in Example 2.2.

[0624] MS m / z(ESI):534.1[M+H] + .

[0625] 1H NMR (400MHz, DMSO-d6) δ10.97(s,1H),9.20(s,1H),7.75(s,1H),7.57(d,J=7.6Hz,2H),7.38(dd,J=8.4,1.6Hz,1H),7.21-7.18(m,3H),7.06(s, 1H),7.01–6.89(m,3H),5.06(dd,J=13.2,5.2Hz,1H),4.40-4.21(m,4H) ,2.94–2.86(m,1H),2.59(m,1H),2.39–2.29(m,1H),2.03–1.92(m,1H).

[0626] Example 2.5: Preparation of Compound PC6

[0627] Compound PC6 was synthesized by a similar method as described in Example 2.2.

[0628] MS m / z(ESI):498.1[M+H] + .

[0629] 1 H NMR (400MHz, DMSO-d6) δ10.97(s,1H),9.24(s,1H),7.76(d,J=1.8Hz,1H),7.56(d,J=7.8Hz,1H ),7.40(dd,J=7.8,1.8Hz,1H),7.26–7.17(m,2H),7.12(d,J=7.8Hz,1H),6.91(t,J=6.0Hz,1H), 5.07(dd,J=13.2,5.0Hz,1H),4.42(d,J=17.2Hz,1H),4.38(d,J=1.2Hz,1H),4.36–4.34(m,3H), 3.47–3.38(m,4H),3.15–3.05(m,1H),2.59–2.50(m,2H),2.10–2.01(m,1H),1.94–1.90(m,1H).

[0630] Example 3: Preparation of linker-payload for ligand drug conjugates

[0631] Example 3.1: Preparation of compound LP15

[0632] Step 1: Synthesis of compound LP15-1

[0633] Compound INT1 (100.36 mg, 0.18 mmol), HATU (102.66 mg, 0.27 mmol), and DIPEA (34.89 mg, 0.27 mmol) were dissolved in anhydrous NMP (5 mL) and stirred at room temperature for 1 h. Compound PA1 (75.86 mg, 0.18 mmol) was then added. After completion of the reaction, ice water and ethyl acetate were added, stirred, and the layers separated. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The crude product was purified by reverse HPLC to afford compound LP15-1 (51.90 mg, 30% yield).

[0634] Step 2: Synthesis of compound II-1-2

[0635] Compound LP15-1 (19.22 mg, 0.02 mmol) was dissolved in dichloromethane / trifluoroacetic acid (3 mL) and stirred at room temperature for 0.5 h. After completion of the reaction, the mixture was concentrated to dryness under reduced pressure. The crude product was purified by reverse-phase HPLC to afford compound LP15 (3.62 mg, 20% yield).

[0636] MS m / z(ESI):905.8[M+H] + .

[0637] Example 3.2: Preparation of compound LP11

[0638] Step 1: Synthesis of compound LP11-1

[0639] Compound PA23 (52.80 mg, 0.10 mmol), compound INT3 (72.37 mg, 0.10 mmol), and DIEA (25.85 mg, 0.20 mmol) were dissolved in DMF (5 mL) and stirred at room temperature for 2 h. After completion of the reaction, water and ethyl acetate were added, stirred, and the layers separated. The organic phase was dried over anhydrous sodium sulfate and concentrated to dryness. The crude product was purified by column chromatography to obtain compound LP11-1 (77.88 mg, 70% yield).

[0640] Step 2: Synthesis of compound LP11

[0641] Compound LP11 was synthesized by a method similar to step 2 in Example 3.1.

[0642] MS m / z(ESI):1057.5[M+H] + .

[0643] Example 3.3: Preparation of compound LP22

[0644] Compound LP22 was synthesized according to the method of Example 3.1.

[0645] MS m / z(ESI):929.3[M+H] + .

[0646] Example 4: Preparation of Ligand Drug Conjugates

[0647] Antibodies serving as ligands are prepared according to conventional methods. For example, vector construction can be performed, followed by transfection into eukaryotic cells such as HEK293 or CHO cells, followed by purification and expression. Ligand-drug conjugates were prepared using the anti-HER3 antibody Patritumab (prepared according to WO2007077028A2) and the anti-GPC-3 antibody Codrituzumab (prepared according to WO2006006693) as examples.

[0648] Anti-HER3 antibody Patritumab heavy chain amino acid sequence

[0649] Anti-HER3 antibody Patritumab light chain amino acid sequence

[0650] Anti-GPC-3 antibody Codrituzumab heavy chain amino acid sequence

[0651] Anti-GPC-3 antibody Codrituzumab light chain amino acid sequence

[0652] Example 4.1: Preparation of ADC-6

[0653] At 37°C, prepared TCEP (10 mM, 0.135 mL, 1.35 μmol) was added to the buffer of Patritumab monoclonal antibody (14.0 mM succinate-sodium hydroxide + 108 mM NaCl pH 6.0; 20 mg, 10.0 mg / mL, 0.135 μmol), placed in a water bath shaker, and shaken at 37°C for 3 hours, then cooled to room temperature.

[0654] Compound LP15 (1.49 mg, 1.65 μmol) was dissolved in 0.1 mL of DMSO and added to the above solution. The mixture was shaken in a water bath at 22° C. for 2 hours to stop the reaction. The reaction solution was desalted and purified using a Sephadex G25 gel column (elution phase: 20 mM histidine-hydrochloric acid pH 5.5) to obtain a solution of the exemplary product ADC-5 (20 mM histidine-hydrochloric acid pH 5.5; 18 mg, 3.6 mg / mL, yield: 90%), which was stored at 4° C.

[0655] The DAR value q was calculated by LC-MS analysis and detection = 7.81.

[0656] Referring to the method of Example 4.1, the following compounds were synthesized using appropriate linker-payloads, wherein Ab1 is Patritumab and Ab2 is Codrituzumab.

[0657] Example 5: In vitro tumor cell proliferation inhibition test of compounds

[0658] Purpose of the test

[0659] In order to detect the inhibitory activity of drug compounds on the proliferation of BT474, HCC1569 and hepG2 tumor cells in vitro, cells were treated with different concentrations of compounds in vitro and cultured for 6 days. Luminescent Cell Viability Assay (Promega, Catalog No. G7558) was used to detect cell proliferation. 50 The in vitro activity of the compound was evaluated.

[0660] Experimental methods

[0661] The following uses the in vitro proliferation inhibition test method of BT474 cells as an example to illustrate the method for testing the in vitro proliferation inhibition activity of the compounds of the present application on tumor cells. This method is also applicable to, but not limited to, testing the in vitro proliferation inhibition activity of other tumor cells.

[0662] 1) Cell culture: BT474 cells were cultured in RPMI-1640 medium supplemented with 10% FBS.

[0663] 2) Cell Preparation: Take BT474 cells in the logarithmic growth phase, wash once with PBS, and then add 2-3 ml of trypsin to digest for 2-3 minutes. After complete digestion, add 10-15 ml of cell culture medium to elute the digested cells. Centrifuge at 1000 rpm for 5 minutes, discard the supernatant, and resuspend the cells in 10-20 ml of cell culture medium to prepare a single-cell suspension.

[0664] 3) Cell plating: Mix the BT474 single cell suspension and adjust the viable cell density to 6x10 4 The cell suspension after density adjustment was mixed and added to a 96-well cell culture plate at 50 μl / well. The culture plate was cultured in an incubator (37° C., 5% CO 2 ) for 18 hours.

[0665] 4) Compound Preparation: Dissolve the compound in DMSO and prepare a stock solution with an initial concentration of 10 mM. Eight concentrations of small molecule compounds are used: 300, 100, 30, 10, 3, 1, 0.3, and 0.1 nM.

[0666] 5) Sample addition: Add different concentrations of the test samples to the culture plate, with two replicates for each sample, and incubate the culture plate in an incubator (37° C., 5% CO 2 ) for 6 days.

[0667] 6) Color development: Take out the 96-well cell culture plate, add 50 μl of CTG reagent to each well, and incubate at room temperature for 10 minutes.

[0668] 7) Plate reading: Take out the 96-well cell culture plate, place it in a microplate reader, and measure the chemiluminescence using the microplate reader.

[0669] Data Analysis

[0670] The data were processed and analyzed using Microsoft Excel and Graphpad Prism 5.

[0671] Table 1 IC values ​​of the small molecule fragments in this application for inhibition of proliferation of BT474, HCC1569, and HepG2 cells in vitro 50 value.

[0672] ++++:<1nM,+++:1~30nM,++:30~100nM,+:>100nM

[0673] Conclusion: The small molecule fragment in this application has obvious proliferation inhibitory activity on BT474, HCC1569 and HepG2 cells.

[0674] Example 6: In vitro cell proliferation inhibition activity test of antibody-drug conjugates

[0675] Example 6.1: In vitro proliferation inhibition activity test of HCC1569 / HepG2 cells

[0676] use The chemiluminescent cell viability assay (i.e., CTG method) was used to evaluate the inhibitory effect of the ADC drug of the anti-Her3 antibody Patritumab coupled with a protein degrader compound on cell proliferation after incubation for 6 days in Her3-positive human breast cancer cells HCC1569; and the inhibitory effect of the ADC drug of the anti-GPC-3 antibody DB1002 coupled with a protein degrader compound on cell proliferation after incubation for 6 days in GPC-3-positive human liver cancer cells HepG2.

[0677] Cells in the logarithmic growth phase were collected and plated in a 96-well cell culture plate at a density of 6000 cells / well. The cell plates were placed in a 37°C, 5% CO2 incubator for overnight culture. On the second day of the experiment, the ADC drug of the camptothecin compound was diluted 3-fold with complete culture medium to obtain 9 concentration gradients (starting with the highest concentration of 300nM). After the drug was added, 100μL / well was added to the cell culture plate. The complete culture medium was used as a blank control, and 3 replicates were set up; the plate was continued to be incubated in a 37°C, 5% CO2 incubator for 6 days. After the incubation was completed, the cell culture plate was removed and equilibrated to room temperature. 50μL CTG detection reagent (Promega, Cat#: G7573) was added to each well. After shaking and mixing, it was placed in the dark for 10 minutes, and the signal value was read using an enzyme reader. GraphPad Prism software was used to draw a S-type dose-response curve using a nonlinear regression model and calculate the IC 50 Cell viability calculation formula = (Lum 待测药 -Lum 空白对照 ) / (Lum 溶剂空白对照 -Lum 空白对照 )×100%.

[0678] ++++: <1nM, +++: 1~10nM, ++: 10~100nM

[0679] Experimental conclusion: The antibody-drug conjugate of the present application has significant proliferation inhibitory activity against Her3-positive human breast cancer cells HCC1569; in addition, it has significant proliferation inhibitory activity against GPC-3-positive human liver cancer cells HepG2.

[0680] Sequences of this application (Kabat numbering scheme):

Claims

1. A ligand-drug conjugate, or a tautomer, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt or solvate thereof, wherein the ligand-drug conjugate comprises a ligand and a structure represented by formula (I): in, R 1 For hydrogen, deuterium, halogen, C 1-6 Alkyl or halogenated C 1-6 alkyl; Ring A is: Among them, 1 is connected to V, and 2 is connected to piperidinedione; U is -CH2- or -C(O)-; R a are independently hydrogen, halogen, -OH, -CN, -NH2, nitro, C 1-6 Alkyl, -OC 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl or 4 to 12 membered heterocycloalkyl; the C 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl or 4- to 12-membered heterocycloalkyl are each optionally substituted with one or more substituents selected from halogen, -OH, -CN, -NH2 and oxo; k2 is 0, 1, 2, or 3; V is -NH- or -O-; L is a chemical bond, -C 1-6 Alkylene or -halogenated C 1-6 Alkylene-; Ring B is C 6-10 aryl, 5-10 membered heteroaryl, or 4- to 12-membered heterocycloalkyl; R 2 are independently hydrogen, deuterium, halogen, nitro, -CN, -OH, -NH2, C 1-6 Alkyl, -OC 1-6 Alkyl, -NHC 1-6 Alkyl, -N(C 1-6 Alkyl)2, C 2-6 Alkenyl, C 2-6 Alkynyl, -CONH2, -COOH, -QC 0-6 Alkylene-C 3-12 Cycloalkyl, -QC 0-6 Alkylene-(4-12 membered heterocycloalkyl), -QC 0-6 Alkylene-C 6-10 Aryl or -QC 0-6 Alkylene-(5-10 membered heteroaryl); the C 1-6 Alkyl, C 0- 6 alkylene, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl, 4-12 membered heterocycloalkyl, C 6-10 Aryl or 5-10 membered heteroarylene is optionally substituted with one or more halogen, -CN, -OH, -NH2, C 1-6 Alkyl, oxo, halo 1-6 Alkyl, -OC 1-6 Alkyl, -NHC 1-6 Alkyl and -N(C 1-6 alkyl)2 substituted; Or, any two adjacent R 2 Together with the atoms it is connected to form C 5-8 Cycloalkyl or 5- to 8-membered heterocycloalkyl; Q is each independently a chemical bond, -O-, -S-, or -NH-; k1 is 0, 1, 2, or 3; W is a chemical bond, -O-, -S-, -NR w -、-C 1-6 Alkylene- or -(C 1-6 alkylene) m1 -(X) m2 -(C 1-6 alkylene) m3 -(Y) m4 -; X and Y are each independently selected from -O-, -S-, -NR w -、-C(O)-、-NR c C(O)-、-C(O)NR w -, -S(O)-, -S(O)2-, -S(O)2NR w -、-NR w S(O)2-, or -OC(O)-; the C 1-6 The alkylene group is optionally substituted with one or more halogens; m1, m2, m3 and m4 are each independently 0 or 1; and m2 and m4 are not 0 at the same time, and m1 and m3 are not 0 at the same time; R w For hydrogen, C 1-6 Alkyl, C 6-10 Aryl, C 3-12 Cycloalkyl, 5-10 membered heteroaryl or 4 to 12 membered heterocycloalkyl; the C 1-6 Alkyl, C 6-10 Aryl, C 3-12 Cycloalkyl, 5-10 membered heteroaryl or 4 to 12 membered heterocycloalkyl are each optionally substituted by one or more radicals selected from halogen, -CN, -OH, -NH2, C 1-6 Alkyl and halogenated C 1-6 Alkyl substitution; or R w Can be used with R 2 and the N atom and C atom to which it is connected together form a 5-12 membered heterocycloalkyl group; the heterocycloalkyl group is optionally substituted by one or more halogen, -CN, -OH, -NH2, C 1-6 Alkyl and halogenated C 1-6 Alkyl substitution; R 3 For chemical bonds, C 1-6 Alkylene, C 2-6 Alkenylene, C 2-6 Alkynylidene, C 3-12 Cycloalkylene, 4 to 12 membered heterocycloalkylene, C 6- 10 Arylene or 5-10 membered heteroarylene; the C 1-6 Alkylene, C 2-6 Alkenylene, C 2-6 Alkynylidene, C 3-12 Cycloalkylene, 4 to 12 membered heterocycloalkylene, C 6-10 Arylene or 5-10 membered heteroarylene are each optionally substituted by one or more selected from halogen, -OH, -CN, -NH2, -SH, nitro, -OC 1-6 Alkyl, -O(halogenated C 1-6 Alkyl), -NHC 1-6 Alkyl, -N(C 1-6 Alkyl)2, -SC 1-6 Alkyl, C 1-6 Alkyl, halogenated C 1-6 Alkyl, -C 1-6 Alkyl-OH, -C 1-6 Alkyl-OC 1-6 Alkyl, -C 1-6 Alkyl-SH, -C 1-6 Alkyl-SC 1-6 Alkyl, -C 1-6 Alkyl-NH2, -C 1-6 Alkyl-NH(C 1-6 Alkyl), -C 1-6 Alkyl-N(C 1-6 Alkyl)2, -C(O)NH2, -COOH, -C(O)NHC 1-6 Alkyl, -C(O)N(C 1-6 Alkyl)2, -NHC(O)C 1-6 Alkyl, -NHC(O)OC 1-6 Alkyl, -S(O)2C 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-6 cycloalkyl and 4- to 6-membered heterocycloalkyl substitution; Z is a chemical bond, -C 0-6 Alkylene-NH-, -C 0-6 Alkylene-N(C 1-6 Alkyl)-, -C 0-6 Alkylene-O- or -C 0-6 Alkylene-S-.

2. The ligand-drug conjugate according to claim 1, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, wherein: The structure represented by formula (I) satisfies one or more of the following conditions: (1)R 1 is hydrogen, deuterium or -CH3; preferably, R 1 is H; (2) Ring A is: Preferably, Ring A is: More preferably, Ring A is Wherein, 1 is connected to V, 2 is connected to piperidinedione; k2 is 0 or 1; (3)R a are each independently hydrogen, deuterium, halogen, -OH, -CN, -NH2, nitro, -CH3 or -OCH3; preferably, R a is hydrogen, F, -OH, -NH2 or -CH3; more preferably, R a is hydrogen or F; (4) V is -NH-; (5) V is -O-; (6) L is a chemical bond or -CH2-; preferably, L is -CH2-; (7) Ring B is C 6-10 Aryl, 5-10 membered heteroaryl or 5 to 10 membered heterocycloalkyl; preferably, ring B is phenyl or pyridyl; more preferably, ring B is phenyl; (8) k1 is 0, 1 or 2; preferably, k1 is 0 or 1; (9)R 2 are independently hydrogen, halogen, -CN, -OH, C 1-6 Alkyl, -OC 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl or 4-12 membered heterocycloalkyl; the C 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-12 Cycloalkyl or 4-12 membered heterocycloalkyl are each optionally substituted with one or more halogen, C 1-6 Alkyl, -OC 1-6 Alkyl and halogenated C 1-6 Alkyl substituted; preferably, R 2 Each is independently hydrogen, F, Cl, Br, -CN, -CH3, -iPr, -tBu, -CF3, -CHF2, -OCH3, -OCF3, -O-CH2-CH2-O-CH3, cyclopropyl, vinyl or ethynyl; more preferably, R 2 are each independently hydrogen, F, Cl, -CH3 or -CF3; (10)R 2 Each independently -OC 6-10 Aryl, -O-CH2-C 6-10 Aryl, -CH2-C 6-10 Aryl, -O-(5-6 membered heteroaryl), -O-CH2-(5-6 membered heteroaryl), -CH2-(5-6 membered heteroaryl), -SC 6-10 Aryl or -S-(5-6 membered heteroaryl); the -CH2-, C 6-10 Aryl or 5-6 membered heteroaryl are each optionally substituted with one or more F, Cl, C 1-6 Alkyl and halogenated C 1-6 Alkyl substitution; Preferably, R 2 Each is independently -O-phenyl, -O-CH2-phenyl, -CH2-phenyl, -O-pyridyl, -O-CH2-pyridyl, -CH2-pyridyl, -S-phenyl or -S-pyridyl; the phenyl and pyridyl groups are each optionally substituted with one or more F, Cl, -CH3 and -CF3; (11)W is a chemical bond, -O-, -S-, -NH-, -C 1-3 Alkylene-, -N(C 1-3 Alkyl)-, -(C 1-3 alkylene) m1 -(O) m2 -(C 1-3 alkylene) m3 -(O) m4 -、-(C 1-3 alkylene) m1 -(O) m2 -(C 1-3 alkylene) m3 -(N(C 1-6 alkyl)) m4 -、-(C 1-3 alkylene) m1 -(N(C 1-6 alkyl)) m2 -(C 1-3 alkylene) m3 -(O) m4 -or-(C 1-3 alkylene) m1 -(N(C 1-6 alkyl)) m2 -(C 1-3 alkylene) m3 -(N(C 1-6 alkyl)) m4 -; (12)W and R 2 and the N atom and C atom to which it is connected together form a 5-6 membered heterocycloalkyl group; the heterocycloalkyl group is optionally substituted by one or more halogen, -C 1-6 Alkyl and -halogenated C 1-6 Alkyl substitution; (13)R 3 For chemical bonds, C 1-4 Alkylene, C 3-6 Cycloalkylene, 4 to 6 membered heterocycloalkylene, C 6-10 Arylene or 5-6 membered heteroarylene; the C 1-4 Alkylene, C 3-6 Cycloalkylene, 4 to 6 membered heterocycloalkylene, C 6-10 Arylene or 5-6 membered heteroarylene are each optionally substituted by one or more selected from halogen, -OH, -CN, -OC 1-6 Alkyl, -O(halogenated C 1-6 Alkyl), -NHC 1-6 Alkyl, -N(C 1-6 Alkyl)2, C 1-6 Alkyl, halogenated C 1-6 Alkyl, -C 1-6 Alkyl-OC 1-6 Alkyl, C 2-6 Alkenyl, C 2-6 Alkynyl, C 3-6 cycloalkyl and 4- to 6-membered heterocycloalkyl substitution; Preferably, R 3 is a chemical bond, phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperazylene, piperidylene, morpholinylene, azetidinylene, azetidinylene, oxetanylene or oxetanylene; the phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperazylene, piperidylene, morpholinylene, azetidinylene, azetidinylene, oxetanylene or oxetanylene are each optionally substituted by one or more halogen, -OH, -CN, -OC 1-6 Alkyl, -O(halogenated C 1-6 Alkyl), C 1-6 Alkyl, halogenated C 1-6 Alkyl or C 3-6 cycloalkyl substitution; More preferably, R 3 is a chemical bond, phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperazylene, piperidylene, morpholinylene, azetidinylene, azetidinylene, oxetanylene or oxetanylene; the phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperazylene, piperidylene, morpholinylene, azetidinylene, azetidinylene, oxetanylene or oxetanylene are each optionally substituted by one or more selected from F, Cl, -OH, -CN, -OC 1-6 Alkyl, -O(halogenated C 1-6 Alkyl), C 1-6 Alkyl, halogenated C 1-6 Alkyl or C 3-6 cycloalkyl substitution; More preferably, R 3 is a chemical bond, a phenylene group, a pyridylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a piperazylene group, a piperidylene group, a morpholinyl group, an azetidinyl group or an azetidinyl group; each of the phenylene group, the pyridylene group, the cyclobutylene group, the cyclopentylene group, the cyclohexylene group, the piperazylene group, the piperidylene group, a morpholinyl group, an azetidinyl group or an azetidinyl group is optionally substituted with one or more groups selected from F, Cl, -OH, -CN, -OCH3, -OCF3, -CH3, -iPr, -tBu, -CF3 or -cyclopropyl; (14) Z is a chemical bond, provided that W and R 3 cannot also be chemical bonds; and (15) Z is -NH- or -N(CH3)-; preferably, Z is -NH-.

3. The ligand-drug conjugate according to claim 1, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, wherein: The structure represented by formula (I) satisfies one or more of the following conditions: (1) Each halogen is independently fluorine, chlorine, bromine or iodine, preferably fluorine; (2) Each C 1-6 Alkyl is independently methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl or sec-butyl, for example methyl; (3) Each -OC 1-6 Alkyl is independently -O-methyl, -O-ethyl, -O-n-propyl, -O-isopropyl, -O-n-butyl, -O-tert-butyl, -O-isobutyl or -O-sec-butyl; for example, -O-methyl; (4) Each C 2-6 Alkenyl is independently ethenyl, propenyl, allyl, butenyl or pentenyl; (5) Each C 2-6 Alkynyl is independently ethynyl, propynyl, propargyl, butynyl or pentynyl, for example (6) Each C 3-12 Cycloalkyl is independently C 3-8 cycloalkyl, such as cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl; (7) each 4- to 12-membered heterocycloalkyl group is independently a 5- to 8-membered heterocycloalkyl group; (8) The heteroatom of each 4- to 12-membered heterocycloalkyl group is independently N, O or S, and the number of heteroatoms is independently 1, 2 or 3; preferably, the heteroatom of each 4- to 12-membered heterocycloalkyl group is independently N or O, and the number of heteroatoms is independently 1 or 2; (9) Each 4- to 12-membered heterocycloalkyl group is independently a monocyclic or polycyclic ring, and the polycyclic ring may be a bridged ring, a fused ring, or a spiro ring; the polycyclic ring may be a bicyclic or tricyclic ring; preferably, each 4- to 12-membered heterocycloalkyl group is independently a 5- to 6-membered monocyclic heterocycloalkyl group, a 9- to 10-membered bicyclic heterocycloalkyl group, or an 11- to 12-membered tricyclic heterocycloalkyl group; (10) Each C 1-6 The alkylene group is independently methylene, ethylene, n-propylene, isopropylene, n-butylene, tert-butylene, isobutylene or sec-butylene, preferably methylene; (11) Each C 6-10 Aryl is independently phenyl or naphthyl, for example phenyl; (12) The heteroatoms of each 5-10 membered heteroaryl group are independently N, O or S, and the number of heteroatoms is independently 1, 2 or 3; (13) Each 5-10 membered heteroaryl group is independently a monocyclic or bicyclic ring, wherein the bicyclic ring is a fused ring; (14) each 4- to 14-membered heterocycloalkyl group is a 5- to 12-membered heterocycloalkyl group; (15) The heteroatom of each 4- to 14-membered heterocycloalkyl group is N, O, or S, and the number of heteroatoms is 1, 2, or 3; preferably, the heteroatom is N, and the number of heteroatoms is 1 or 2; (16) Each 4- to 14-membered heterocycloalkyl group may be monocyclic or polycyclic, such as bicyclic or tricyclic, and the polycyclic rings may be bridged, fused, or spirocyclic; (17) Each 4- to 14-membered heterocycloalkyl group contains 0, 1 or 2 unsaturated rings, preferably 1 unsaturated ring and at least one saturated ring; the unsaturated ring is preferably an aromatic ring; (18) When each 4- to 14-membered heterocycloalkyl group contains one unsaturated ring and at least one saturated ring, the heteroatom is located in the saturated ring; (19) Each 4- to 14-membered heterocycloalkyl group contains 0, 1, or 2 unsaturated bonds; (20) Each 4- to 14-membered heterocycloalkyl group is a monocyclic heterocycloalkyl group, a bicyclic heterocycloalkyl group, or a tricyclic heterocycloalkyl group; preferably, a 5- to 6-membered monocyclic heterocycloalkyl group, a 9- to 10-membered bicyclic heterocycloalkyl group, or an 11- to 14-membered tricyclic heterocycloalkyl group; for example and (21) Each C 0-6 The alkylene group is independently a link, a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, a tert-butylene group, an isobutylene group or a sec-butylene group, preferably a link, a methylene group or an ethylene group.

4. The ligand-drug conjugate according to any one of claims 1 to 3, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, characterized in that: The structure shown in formula (I) satisfies any of the following schemes: Option 1: The structure shown in formula (I) is the structure shown in formula (Ia): Among them, R 1 、R a 、R 2 、R 3 , V, L, W, Z, ring B, k1 and k2 are as defined in any one of claims 1 to 3; Option 2: The structure shown in formula (I) is the structure shown in formula (Ib): Among them, R a 、R 2 、R 3 , W, Z, k1 and k2 are defined as in any one of claims 1 to 3; Option 3: The structure shown in formula (I) is the structure shown in formula (Ib-1): Among them, R a 、R 2 , W, k1 and k2 are defined as described in any one of claims 1-3; Better, R 2 Each is independently hydrogen, F, Cl, Br, -CN, -CH3, -iPr, -tBu, -CF3, -CHF2, -OCH3, -OCF3, -O-CH2-CH2-O-CH3, cyclopropyl, vinyl or ethynyl; preferably, R 2 Each is independently hydrogen, F, Cl, -tBu, -O-CH2-CH2-O-CH3; Or, any two adjacent R 2 Together with the atoms it is connected to form C 5-8 Cycloalkyl, 5 to 8 membered heterocycloalkyl; preferably, two adjacent R 2 Together with the atoms it is connected to, it forms The C 5-8 Cycloalkyl, 5- to 8-membered heterocycloalkyl or Each is optionally substituted by one or more halogen, -CN, -OH, -NH2, C 1-6 Alkyl, oxo, halo 1-6 Alkyl, -OC 1-6 Alkyl, -NHC 1-6 Alkyl and -N(C 1-6 alkyl)2 substituted; Or, R 2 Each is independently -O-phenyl, -O-CH2-phenyl, -CH2-phenyl, -O-pyridyl, -O-CH2-pyridyl, -CH2-pyridyl, -S-phenyl or -S-pyridyl; preferably, R 2 Each is independently -O-phenyl, -O-CH2-phenyl, -CH2-phenyl, -O-pyridyl, -O-CH2-pyridyl, -S-phenyl; the phenyl and pyridyl groups are each optionally substituted with one or more F, Cl, -CH3 and -CF3; W is -NH-, -N(C 1-3 alkyl)-, -CH2CH2-O-CH2CH2-NH-, -CH2CH2-O-CH2CH2-N(CH3)-, -CH2-O-CH2CH2-N(CH3)-, -CH2-O-CH2CH2CH2-N(CH3)-, -O-CH2CH2-NH- or -O-CH2CH2-N(CH3)-; preferably, W is -NH-, -N(C 1-3 alkyl)-, -CH2CH2-O-CH2CH2-N(CH3)-, -O-CH2CH2-N(CH3)-, or -CH2-O-CH2CH2CH2-N(CH3)-; Or, W and R 2 Together with its connected N and C atoms, it forms Side a is connected to ring B in a parallel ring; Better, R 2 Each is independently hydrogen, F, Cl, -CH3, -O-phenyl, -S-phenyl; W is -NH-, -CH2CH2-O-CH2CH2-N(CH3)- or -O-CH2CH2-N(CH3)-; Or, W and R 2 Together with its connected N and C atoms, it forms Side a is connected to ring B in a parallel ring; Option 4: The structure represented by formula (I) is the structure represented by (Ib-1a), (Ib-1b), (Ib-1c), (Ib-1d) or (Ib-1e): R a 、R 2 and W are defined as described in any one of claims 1-3 or as described in Scheme 3; Option 5: The structure shown in formula (I) is the structure shown in formula (Ib-2): in, R a 、R 2 、R 3 , W, k1 and k2 are defined as described in any one of claims 1-3; Better, R 2 Each independently represents hydrogen, F, Cl, Br, -CN, -CH3, -CF3, -CHF2, -OCH3 or -OCF3; preferably, R 2 are each independently hydrogen, F or Cl; W is a chemical bond, -O-, -S-, -NR w -, -CH2-, -CH2CH2-O-, -O-CH2CH2-, -CH2-O-CH2-, -CH2-O- or -O-CH2-; Preferably, W is a chemical bond, -O-, -S-, -CH2-, -CH2CH2-O-, -O-CH2CH2-, -CH2-O-CH2-, -CH2-O- or -O-CH2-; R w is hydrogen or -C 1-6 Alkyl; preferably hydrogen; R 3 is phenylene, pyridylene, cyclobutylene, cyclopentylene, cyclohexylene, piperidylene, azetidinylene or azetidinylene; preferably, R 3 is phenylene, cyclobutylene, cyclohexylene, piperidinylene or azetidinylene; each of the phenylene, pyridinylene, cyclobutylene, cyclopentylene, cyclohexylene, piperidinylene, azetidinylene or azetidinylene is optionally substituted with one or more selected from F, Cl, -OH, -CN, -OCH3, -OCF3, -CH3, -iPr, -tBu, -CF3 or -cyclopropyl; Better, R 2 are each independently hydrogen, F or Cl; W is -S-, -O-CH2- or -CH2-O-; R 3 is phenylene; Better, for Option 6: The structure represented by formula (I) is the structure represented by (Ib-2a), (Ib-2b) or (Ib-2c): in, R 2 、R 3 and W is defined as in any one of claims 1-3; Option 7: The structure shown in formula (I) is the structure shown in formula (Ib-3): R 3 for wherein the a end is connected to W; ring D is a 4 to 12 membered heterocycloalkylene; each of the 4 to 12 membered heterocycloalkylene is optionally substituted with one or more selected from halogen, -OH, -CN, -NH2, nitro, -OC 1-6 Alkyl, -O(halogenated C 1-6 Alkyl), C 1-6 Alkyl, halogenated C 1-6 Alkyl substitution; R a 、R 2 , W, k1 and k2 are defined as described in any one of claims 1-3; Preferably, R 2 Each independently represents hydrogen, F, Cl, Br, -CN, -CH3, -CF3, -CHF2, -OCH3 or -OCF3; preferably, R 2 are each independently hydrogen, F, Cl or -CH3; W is a chemical bond, -O-, -CH2CH2-O-CH2-, -CH2CH2-O-, -CH2-O-CH2CH2-, -CH2-O-, -O-CH2CH2- or -OCH2-; preferably, W is a chemical bond, -O-, -CH2CH2-O-, -O-CH2CH2-, -CH2-O-CH2-, -CH2-O- or -O-CH2-; more preferably, W is -CH2-O- or -O-CH2-; R 3 for Preferably, R 3 for More preferably, R 3 for Among them, end a is connected to W; Preferably, for Among them, the a-end is connected to the A ring; Option 8: The structure represented by formula (I) is the structure represented by (Ib-3a), (Ib-3b) or (Ib-3c): in, R 2 、R 3 and W is defined as in any one of claims 1-3; Option 9: The structure shown in formula (I) is any of the following structures:

5. The ligand-drug conjugate according to any one of claims 1 to 4, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, characterized in that: The ligand-drug conjugate comprises a ligand and a structure represented by formula (II): in, Linker is a connecting subunit that binds to the ligand and can be cleavable or non-cleavable; R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of claims 1 to 3; Preferably, the structure represented by formula (II) is the structure represented by formula (II-1): in, R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of claims 1 to 3; The wavy line indicates the L 1 The nitrogen or carbon atom on the group is connected to the ligand; L 1 for Where a end and L 2 connected; L 2 -(C(RL 21 )2) n -, Wherein, n is a natural number from 0 to 50, such as 0, 1, 2, 3, 4, 5, 6, 7 or 8; L 2 Any C(R L21 )2 units are each independently replaced by the following structural units: -Cy-, -C(O)-, -NR L22 -, -O-, -S-, -SO-, -SO2-, -P(R L22 )-、-P(=O)(R L22 )-、-(R L22 )P(=O)-, -C(=S)-, -C(=NR L22 )-, -N=N-, -C=N-, -N=C-, -Cy- is phenylene, 5- to 8-membered heteroarylene, 3- to 10-membered heterocyclylene, or 3- to 10-membered cycloalkylene, wherein the -Cy- is independently substituted by one or more R cx replace; R L21 、R L22 、R cx Each independently selected from hydrogen, deuterium, halogen, -NO2, -CN, -OR L2a 、-SR L2a 、-N(R L2a )2, -N + (R L2a )3, -C(O)R L2a 、-CO2R L2a 、-C(O)C(O)R L2a 、-C(O)CH2C(O)R L2a 、-S(O)R L2a 、-S(O)2R L2a 、-C(O)N(R L2a )2、-SO2N(R L2a )2、-OC(O)R L2a 、-N(R L2a )SO2R L2b 、-N(R L2a )COR L2b 、-(CH2) y -CO-(N(Me)CH2C(O)) m -OR L2a 、-(CH2) y -CO-(N(Me)CH2C(O)) m -NHR L2a 、-(CH2) y -CO-(N(Me)CH2C(O)) m -N + (R L2a )3, -(CH2) y -NHCOCH2(OCH2CH2)OR L2a 、-(CH2) y -NH(COCH2(N(Me)) m -R L2a 、-(CH2) y -CONH-(CH2CH2O) m -R L2a 、-(CH2) y -NHCO-(CH2CH2O) m -R L2a 、-(CH2CH2O) m -R L2a 、-(COCH2N(Me)) m -R L2a 、-COCH2(OCH2CH2) m -OR L2a 、-CO-(CH2CH2O) m -R L2a 、-CO-(CH2) y -CONH-(CH2CH2O) m -R L2a 、-CO-(CH2) y -NHCO-(CH2CH2O) m -R L2a and R L2a Optionally substituted C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl or 3-10 membered heteroaryl; m, y are each a natural number from 0 to 50, such as 0, 1, 2, 3, 4, 5, 6, 7 or 8; R L2a 、R L2b Each independently selected from hydrogen, deuterium, halogen, -NO2, -CN, -OH, -SH, -NH2, -N(Me)2, -CO2H, -S(O)2Me, -S(O)2OH, -C(O)NH2, -SO2NH2, C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl, and 3-10 membered heteroaryl; L 3 Does not exist or is an amino acid residue, a short peptide consisting of 2-10 amino acid residues, Or any combination of the above groups, the amino acid residue is a natural amino acid residue or a non-natural amino acid residue; wherein the a end and L 2 Preferably, the amino acid residue and the nitrogen end of the short peptide consisting of 2-10 amino acid residues are connected to L 2 connected; Tr does not exist or is Or any combination of the above groups; wherein the a end and L 3 connected; R Tr 、R Tr1 and R Tr2 Each independently selected from hydrogen, deuterium, halogen, -NO2, -CN, -OH, -SH, -NH2, -CO2H, -S(O)2OH, -C(O)NH2, -SO2NH2, -OC(O)NH2, -CH2CO-(N(Me)CH2C(O)) z -OR Tra 、-CH2CO-(N(Me)CH2C(O)) z -NHR Tra 、-(CH2CH2O) z -R Tra 、-CONH-(CH2CH2O) z -R Tra and R Tra Optionally substituted C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl or 3-10 membered heteroaryl; R Tra independently selected from hydrogen, deuterium, halogen, -NO2, -CN, -OH, -SH, -NH2, -N(Me)2, -S(O)2Me, -CO2H, -S(O)2OH, -C(O)NH2, -SO2NH2, C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl, and 3-10 membered heteroaryl; z is independently a natural number from 0 to 50; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8.

6. The ligand-drug conjugate according to claim 5, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, wherein: The structure shown in formula (II) satisfies one or more of the following schemes: (1)L 1 Selected from: Preferably, L 1 Selected from Where a end and L 2 connected; (2)L 2 -(CHR L21 ) n -; n is a natural number from 0 to 50; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8; L 2 Any CH2 unit in the is independently replaced by the following structural units: -Cy-, -C(O)-, -NR L22 -、-O-、 -Cy- is phenylene, 5- to 6-membered heteroarylene, 4- to 10-membered heterocyclylene, or 3- to 6-membered cycloalkylene, wherein said -Cy- is independently substituted by 1 to 3 R cx replace; Each R L21 、R L22 、R cx are independently hydrogen, halogen, -OR L2a 、-N(R L2a )2、-C(O)R L2a 、-S(O)2R L2a 、-C(O)N(R L2a )2、-SO2N(R L2a )2、-N(R L2a )SO2R L2b 、-N(R L2a )COR L2b 、-(CH2) y -CO-(N(Me)CH2C(O)) m -OR L2a 、-(CH2) y -CO-(N(Me)CH2C(O)) m -NHR L2a 、-(CH2) y -CONH-(CH2CH2O) m -R L2a 、-(CH2) y -NHCO-(CH2CH2O) m -R L2a 、-(CH2) y -NHCOCH2(OCH2CH2)OR L2a 、-(CH2) y -NH(COCH2(N(Me)) m -R L2a 、-(CH2) y -NHCO-(CH2CH2O) m -R L2a 、-(CH2CH2O) m -R L2a 、-(COCH2N(Me)) m -R L2a 、-COCH2(OCH2CH2) m -OR L2a 、-CO-(CH2CH2O) m -R L2a , or by R L2a Optionally substituted C 1-6 Alkyl, C 1-6 Alkenyl, C 1-6 Alkynyl, 3-8 membered cycloalkyl, 4-10 membered heterocycloalkyl, 6-10 membered aryl or 3-10 membered heteroaryl; m is a natural integer from 0 to 8; y is 0, 1, 2, 3, or 4; Each R L2a 、R L2b Each is independently hydrogen, halogen, -CN, -OH, -NH2, -N(Me)2, -CO2H, -C(O)NH2, C 1-6 alkyl; (3)L 2 -(CH2) n -; n is a natural integer from 0 to 50; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8; L 2 Any methylene unit in is independently replaced by the following structural units: 4 to 6 membered heterocyclyl, 3 to 6 membered cycloalkyl, -C(O)-, -NR L22 -、-O-、 Each R L22 are each independently selected from hydrogen, -OR L2a 、-C(O)R L2a 、-S(O)2R L2a 、-C(O)N(R L2a )2、-SO2N(R L2a )2、-(CH2) y -CO-(N(Me)CH2C(O)) m -OR L2a 、-(CH2) y -CO-(N(Me)CH2C(O)) m -NHR L2a 、-(CH2) y -CONH-(CH2CH2O) m -R L2a 、-(CH2) y -NHCOCH2(OCH2CH2)OR L2a 、-(CH2CH2O) m -R L2a 、-(COCH2N(Me)) m -R L2a 、-COCH2(OCH2CH2) m -OR L2a 、-CO-(CH2CH2O) m -R L2a and R L2a Optionally substituted C 1-6 alkyl; m is a natural integer from 0 to 8; y is 0, 1, 2, 3, or 4; Each R L2a Each is independently hydrogen, halogen, -CN, -OH, -NH2, -N(Me)2, -CO2H, -C(O)NH2, C 1-6 alkyl; (4)L 2 for: Among them, the left side and L 1 connected; in, n1, n2, n3, n4 are each independently a natural number from 0 to 8; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8; n5 and n6 are each independently 0 or 1; -Cy- is a 4- to 6-membered heterocyclylene or a 3- to 6-membered cycloalkylene; preferably, -Cy- is More preferably, -Cy- is The a-end is connected to the carbonyl group; (5) for Among them, the C-terminal and L 1 Connected, d end and L 3 connected; (6) for: Among them, the right side and L 3 connected; n1, n2, n3, n4 are each independently a natural number from 0 to 8; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8; n5 and n6 are each independently 0 or 1; (7) for: Among them, f end and L 3 connected; (8)L 3 Does not exist or is L 3a -L 3b ; L 3a and L 3b Independently, there is no or no amino acid residue, a short peptide consisting of 2-10 amino acid residues, Among them, the a end and L 2 connected; Preferably, L 3a With L 2 connected; Preferably, L 3a Is absent or selected from Val, D-Val, Phe, Lys, Leu, Ile, Gly, Ala, D-Ala, Cit, Asp, Asn, Glu, Gln, Val-Cit, Val-Ala, Val-Lys, Val-Lys(Ac), Phe-Lys, Phe-Lys(Ac), Leu-Lys, Leu-Lys(Ac), Ala-Ala, Ala-Ly s, D-Ala-Ala, Gly-Glu, Gly-Asp, Gly-Asn, Val-Glu, Val-Asp, Asn-Asn, Asp-Glu, Asp-Ser, Gly-Gly-Glu, Gly-Gly-Asp, Gly-Gly-Asn, Gly-Ala-Ala, Gly-Val-Ala, Gly-Val-Cit, Glu-Val-C it, Ala-Ala-Ala, Ala-(D-Ala)-Ala, Ala-Ala-Asn, Ala-(D-Ala)-Asn, Ala-Ala-Asp, Val-Lys-Gly, D-Val-Leu-Lys, Gly-Gly-Arg, Gly-Gly-Gly, Lys-Ala-Asn, Gly-Phe-Gly, Gly-Gly-Phe, Asn-Pro-Val, Ala-Lys-Gly, Gly-Lys-Gly, Gly-Glu-Gly, (Gly)4, (Gly)2-Phe-Gly, (Gly)2-Glu-Gly, Lys-(Ala)2-Asn, Lys-(Ala)2-Asp, (Ala)2-Pro-Val, and (Ala)2-Pro-Nva; wherein the nitrogen terminus of the amino acid residue is adjacent to L 2 connected; L 3b Does not exist or Among them, the a end and L 3a connected; Preferably, L 3a is absent or selected from Lys, Gly, Asp, Asn, Glu, Gln, Val-Cit, Val-Ala, Ala-Ala, Gly-Glu, Gly-Asp, Gly-Asn, Asp-Glu, Gly-Glu-Gly and (Gly)2-Phe-Gly; wherein the nitrogen end of the amino acid residue is adjacent to L 2 connected; L 3b Does not exist or Among them, the a end and L 3a connected; Preferably, L 3a is absent or selected from Val-Cit, Val-Ala, Ala-Ala, Gly-Glu, Gly-Asp, Gly-Asn and (aGly)2-Phe-Gly; wherein the nitrogen end of the amino acid residue is adjacent to L 2 connected; L 3b Does not exist or Among them, the a end and L 3a connected; (9) for: Preferably, for More preferably, for and (10) Tr does not exist or is Among them, the a end and L 3 connected; R Tr 、R Tr1 and R Tr2 are independently hydrogen, halogen, -NO2, -CN, -OH, -NH2, -CO2H, -S(O)2H, -C(O)NH2, -SO2NH2, -OC(O)NH2, -CH2CO-(N(Me)CH2C(O)) z -NHMe, -(CH2CH2O) z -H, -CONH-(CH2CH2O) z -H; z is a natural number from 0 to 8; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8; Preferably, Tr does not exist or is Among them, the a end and L 3 connected.

7. The ligand-drug conjugate according to claim 5 or 6, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, characterized in that: The structure shown in formula (II) satisfies one of the following schemes: Option 1: The structure represented by formula (II) is the structure represented by formula (IIa): in, R 1 、R a 、R 2 、R 3 , V, L, W, Z, ring B, k1 and k2 are as defined in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is as defined in claim 5 or 6; Option 2: The structure represented by formula (II) is the structure represented by formula (IIb): in, R a 、R 2 、R 3 , W, Z, k1 and k2 are defined as described in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is as defined in claim 5 or 6; Option 3: The structure represented by the formula (II) is the structure represented by the formula (IIb-1): in, R a 、R 2 , W, k1 and k2 are defined as described in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is as defined in claim 5 or 6; Option 4: The structure represented by formula (II) is the structure represented by formula (IIb-1a), formula (IIb-1b), formula (IIb-1c), formula (IIb-1d) or formula (IIb-1e): in, Ra, R 2 and W is defined as in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is as defined in claim 5 or 6; Option 5: The structure represented by the formula (II) is the structure represented by the formula (IIb-2): in, R a 、R 2 、R 3 , W, k1 and k2 are defined as described in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is as defined in claim 5 or 6; Option 6: The structure represented by formula (II) is the structure represented by formula (IIb-2a), formula (IIb-2b) or formula (IIb-2c): in, R 2 、R 3 , W is defined as in any one of claims 1-4; L 1 , L 2 , L 3 and Tr is as defined in claim 5 or 6; Option 7: The structure represented by the formula (II) is the structure represented by the formula (IIb-3): in, R a 、R 2 、R 3 , W, k1 and k2 are defined as described in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is as defined in claim 5 or 6; Option 8: The structure represented by formula (II) is the structure represented by formula (IIb-3a), formula (IIb-3b) or formula (IIb-3c): R 2 、R 3 and W is defined as in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is as defined in claim 5 or 6; Option 9: The structure represented by the formula (II) is any of the following structures:

8. The ligand-drug conjugate according to any one of claims 1 to 7, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, characterized in that: The ligand-drug conjugate is a ligand-drug conjugate having a structure represented by formula (III): in, Ab is the ligand that binds to the target; q is the drug loading; R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of claims 1 to 4; The linker is as defined in any one of claims 5-7.

9. The ligand-drug conjugate according to claim 8, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, wherein: The ligand-drug conjugate of the structure represented by formula (III) satisfies one or more of the following conditions: (1) Ab is a target-binding polypeptide, antibody, or antigen-binding fragment thereof, preferably an antibody or antigen-binding fragment thereof; Preferably, when Ab is an antibody, the antibody is selected from one or more of the following: 1) Fully human antibodies, humanized antibodies, mouse antibodies and chimeric antibodies; 2) front resistance; 3) Bispecific antibodies and multispecific antibodies; 4) Monoclonal antibodies and polyclonal antibodies; 5) IgG antibodies; Preferably, when Ab is an antigen-binding fragment, the antigen-binding fragment is selected from the group consisting of: Fab, Fab', F(ab')2, Fv, scFv, Fd, dAb, VHH and complementarity determining region (CDR) fragments (2) Ab is a monoclonal antibody (3) Ab targeting an antigen selected from the group consisting of HER2, HER3, B7H3, B7H4, DLL3, TROP2, Claudin18.2, CD30, CD33, CD70, GPC-3, ADAM9, and EGFR; (4) Ab is an antibody or antigen-binding fragment thereof targeting HER3, B7H3, Claudin18.2, CD30, CD33, CD70, GPC-3, ADAM9, and EGFR; (5) Ab is an antibody or antigen-binding fragment thereof targeting HER3, for example, patrastuzumab or a variant thereof; Preferably, the anti-Her3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region comprises HCDR1, HCDR2 and HCDR3 with amino acid sequences as shown in SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 3, respectively, and the light chain variable region comprises LCDR1, LCDR2 and LCDR3 with amino acid sequences as shown in SEQ ID NO: 4, SEQ ID NO: 5 and SEQ ID NO: 6, respectively; Preferably, the anti-HER3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, the heavy chain variable region amino acid sequence is as shown in SEQ ID NO: 7 or a sequence having at least 95%, 96%, 97%, 98% or 99% identity thereto, and the light chain variable region amino acid sequence is as shown in SEQ ID NO: 8 or a sequence having at least 95%, 96%, 97%, 98% or 99% identity thereto; Preferably, the anti-HER3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, the amino acid sequence of the heavy chain variable region is shown in SEQ ID NO: 7, and the amino acid sequence of the light chain variable region is shown in SEQ ID NO: 8; Preferably, the anti-HER3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain of an antibody, wherein the amino acid sequence of the heavy chain is as shown in SEQ ID NO: 9 or a sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto, and the amino acid sequence of the light chain is as shown in SEQ ID NO: 10 or a sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto; Preferably, in some embodiments, the ligand-drug conjugate of the structure represented by formula (III), wherein the anti-HER3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain of the antibody, wherein the amino acid sequence of the heavy chain is as shown in SEQ ID NO: 9, and the amino acid sequence of the light chain is as shown in SEQ ID NO: 10; (6) Ab is an anti-GPC-3 antibody or an antigen-binding fragment thereof, for example, codrituzumab or a variant thereof; Preferably, the anti-GPC-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein the heavy chain variable region comprises HCDR1, HCDR2, and HCDR3 with amino acid sequences as shown in SEQ ID NO: 11, SEQ ID NO: 12, and SEQ ID NO: 13, respectively, and the light chain variable region comprises LCDR1, LCDR2, and LCDR3 with amino acid sequences as shown in SEQ ID NO: 14, SEQ ID NO: 15, and SEQ ID NO: 16, respectively; Preferably, the anti-GPC-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, wherein the amino acid sequence of the heavy chain variable region is as shown in SEQ ID NO: 17 or a sequence having at least 95%, 96%, 97%, 98% or 99% identity thereto, and the amino acid sequence of the light chain variable region is as shown in SEQ ID NO: 18 or a sequence having at least 95%, 96%, 97%, 98% or 99% identity thereto; Preferably, the anti-GPC-3 antibody or antigen-binding fragment thereof comprises a heavy chain variable region and a light chain variable region, the amino acid sequence of the heavy chain variable region is shown in SEQ ID NO: 17, and the amino acid sequence of the light chain variable region is shown in SEQ ID NO: 18; Preferably, the anti-GPC-3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain of an antibody, wherein the amino acid sequence of the heavy chain is as shown in SEQ ID NO: 19 or a sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto, and the amino acid sequence of the light chain is as shown in SEQ ID NO: 20 or a sequence having at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity thereto; Preferably, the anti-GPC-3 antibody or antigen-binding fragment thereof comprises a heavy chain and a light chain of the antibody, wherein the amino acid sequence of the heavy chain is as shown in SEQ ID NO: 19, and the amino acid sequence of the light chain is as shown in SEQ ID NO: 20; and (7) q is an integer or decimal of 1-32, preferably an integer or decimal of 1-16, more preferably an integer or decimal of 2-8, for example, 2, 3, 4, 5, 6, 7, 8, 7.5, 7.6, 7.7, 7.8 or 7.9; for example, 7.53, 7.64, 7.67 or 7.

89.

10. The ligand-drug conjugate according to claim 8 or 9, or its tautomers, enantiomers, diastereomers, or mixtures thereof, or its pharmaceutically acceptable salts or solvates, characterized in that: The ligand-drug conjugate of the structure represented by formula (III) satisfies one of the following schemes: Option 1: The ligand-drug conjugate of the structure represented by formula (III) is the ligand-drug conjugate represented by formula (III-1): in, R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is defined as in any one of claims 5-7; Ab and q are as defined in claim 8 or 9; Option 2: The ligand-drug conjugate of the structure represented by formula (III) is a ligand-drug conjugate represented by formula (IIIa): in, R 1 、R a 、R 2 、R 3 , V, L, W, Z, ring B, k1 and k2 are as defined in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is defined as in any one of claims 5-7; Ab and q are as defined in claim 8 or 9; Option 3: The ligand-drug conjugate of the structure represented by formula (III) is a ligand-drug conjugate represented by formula (IIIb): in, R a 、R 2 、R 3 , W, Z, k1 and k2 are defined as described in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is defined as in any one of claims 5-7; Ab and q are as defined in claim 8 or 9; Option 4: The ligand-drug conjugate of the structure represented by formula (III) is the ligand-drug conjugate represented by formula (IIIb-1): in, R a 、R 2 , W, k1 and k2 are defined as described in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is defined as in any one of claims 5-7; Ab and q are as defined in claim 8 or 9; Option 5: The ligand-drug conjugate of the structure represented by formula (III) is represented by formula (IIIb-1a), formula (IIIb-1b), formula (IIIb-1c), formula (IIIb-1d) or formula (IIIb-1e): in, R a 、R 2 and W is defined as in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is defined as in any one of claims 5-7; Ab and q are as defined in claim 8 or 9; Option 5: The ligand-drug conjugate of the structure represented by formula (III) is a ligand-drug conjugate represented by formula (IIIb-2): in, R a 、R 2 、R 3 , W, k1 and k2 are defined as described in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is defined as in any one of claims 5-7; Ab and q are as defined in claim 8 or 9; Option 6: The ligand-drug conjugate of formula (III) is represented by formula (IIIb-2a), formula (IIIb-2b) or formula (IIIb-2c): in R 2 、R 3 , W is defined as in any one of claims 1-4; L 1 , L 2 , L 3 and Tr is defined as in any one of claims 5-7; Ab and q are as defined in claim 8 or 9; Option 6: The ligand-drug conjugate of the structure represented by formula (III) is represented by formula (IIIb-3): in, R a 、R 2 , W, k1 and k2 are defined as described in any one of claims 1 to 4; R 3 The definition as described in any one of claims 5 to 7; Ab and q are as defined in claim 8 or 9; Option 7: The ligand-drug conjugate of formula (III) is represented by formula (IIIb-3a), formula (IIIb-3b) or formula (IIIb-3c): R 2 、R 3 and W is defined as in any one of claims 1 to 4; L 1 , L 2 , L 3 and Tr is defined as in any one of claims 5-7; Ab and q are as defined in claim 8 or 9; Option 8: The ligand-drug conjugate of formula (III) is any of the following structures: wherein Ab and q are as defined in claim 8 or 9; Option 8: The ligand-drug conjugate of formula (III) is any of the following structures: in, q is as defined in claim 8 or 9; Ab1 and Ab2 are each independently selected from Patritumab or a variant thereof and Codrituzumab or a variant thereof; Preferably, Abl is pertratuzumab; Abl is coltuzumab.

11. A nitrogen-containing heterocyclic compound represented by formula (IV), or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof: in, linker 1 A linker unit that binds to the ligand; R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of claims 1 to 4.

12. The nitrogen-containing heterocyclic compound of formula (IV) according to claim 11, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, characterized in that: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IV-1): in, R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of claims 1 to 4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a for:

13. The nitrogen-containing heterocyclic compound of formula (IV) according to claim 12, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, characterized in that: The compound represented by the formula (IV-1) satisfies one or more of the following conditions: (1)L 1a for: Preferably, L 1a for (2) for: n1, n2, n3, n4 are each independently a natural number from 0 to 8; for example, 0, 1, 2, 3, 4, 5, 6, 7 or 8; n5 and n6 are each independently 0 or 1; Preferably, for: and (3) for: Preferably, for More preferably, for 14. The nitrogen-containing heterocyclic compound represented by formula (IV) according to any one of claims 11 to 13, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, characterized in that: The nitrogen-containing heterocyclic compound represented by formula (IV) satisfies one of the following schemes: Option 1: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IVa): in, R 1 、R a 、R 2 、R 3 , V, L, W, Z, ring B, k1 and k2 are as defined in any one of claims 1 to 4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a as defined in claim 12 or 13; Option 2: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IVb): in, R a 、R 2 、R 3 , W, Z, k1 and k2 are defined as described in any one of claims 1 to 4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a as defined in claim 12 or 13; Option 3: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IVb-1): in, R a 、R 2 , W, k1 and k2 are defined as described in any one of claims 1 to 4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a as defined in claim 12 or 13; Option 4: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IVb-1a), formula (IVb-1b), formula (IVb-1c), formula (IVb-1d) or formula (IVb-1e): in, R 2 and W is defined as in any one of claims 1 to 4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a as defined in claim 12 or 13; Option 5: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IVb-2): in, R a 、R 2 、R 3 , W, k1 and k2 are defined as described in any one of claims 1 to 4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a as defined in claim 12 or 13; Option 6: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IVb-2a), formula (IVb-2b) or formula (IVb-2c): in, R 2 、R 3 , W is defined as in any one of claims 1-4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a as defined in claim 12 or 13; Option 7: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IVb-3): in, R a 、R 2 , W, k1 and k2 are defined as described in any one of claims 1 to 4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a as defined in claim 12 or 13; Option 8: The nitrogen-containing heterocyclic compound represented by formula (IV) is a compound represented by formula (IVb-3a), formula (IVb-3b) or formula (IVb-3c): in, R 2 , W is defined as in any one of claims 1-4; L 2 , L 3 and Tr is defined as in any one of claims 5-7; L 1a as defined in claim 12 or 13; Plan 9 The nitrogen-containing heterocyclic compound represented by formula (IV) is any of the following compounds:

15. A nitrogen-containing heterocyclic compound represented by formula V, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof, or a solvate thereof, or a pharmaceutically acceptable salt thereof: in, R 1 、R 2 、R 3 , V, L, W, Z, Ring A, Ring B and k1 are as defined in any one of claims 1 to 4.

16. The nitrogen-containing heterocyclic compound of formula V according to claim 15, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or its pharmaceutically acceptable salt, or its solvate, or its pharmaceutically acceptable salt of a solvate, characterized in that: The nitrogen-containing heterocyclic compound represented by formula (V) satisfies one of the following schemes: Option 1: The compound represented by formula (V) is a compound represented by formula (Va): in, R 1 、R a 、R 2 、R 3 , V, L, W, Z, ring B, k1 and k2 are as defined in any one of claims 1 to 4; Option 2: The compound of the structure shown in formula (V) is a compound shown in formula (Vb): in, R a 、R 2 、R 3 , W, Z, k1 and k2 are defined as described in any one of claims 1 to 4; Option 3: The compound represented by formula (V) is a compound represented by formula (Vb-1): in, R a 、R 2 , W, k1 and k2 are defined as described in any one of claims 1 to 4; Preferably, R 2 Each is independently H, F, Cl, -CH3, -O-phenyl, -S-phenyl or -O-CH2-phenyl; W is -NH-, -CH2CH2-O-CH2CH2-N(CH3)- or -O-CH2CH2-N(CH3)-; Or, W and R 2 Together with its connected N and C atoms, it forms Side a is connected to ring B in a parallel ring; Option 4: The compound represented by formula (V) is a compound represented by formula (Vb-1a), (Vb-1b) or (Vb-1c): R 2 and W is defined as in any one of claims 1 to 4; Option 5: The compound represented by formula (V) is a compound represented by formula (Vb-2): in, R a 、R 2 、R 3 , W, k1 and k2 are defined as described in any one of claims 1 to 4; Preferably, R 2 are each independently hydrogen, F or Cl; W is -O-, -S-, or -CH2-O-; R 3 is phenylene; Option 6: The compound represented by the structure of formula (V) is a compound represented by (Vb-2a), (Vb-2b) or (Vb-2c): in, R 2 、R 3 and W is defined as in any one of claims 1 to 4; Option 7: The compound represented by formula (V) is a compound represented by formula (Vb-3): in, R a 、R 2 、R 3 , W, k1 and k2 are defined as described in any one of claims 1 to 4; Preferably, R 2 are each independently hydrogen, F, Cl or -CH3; W is -CH2CH2-O-, -O-CH2CH2-, -CH2-O- or -O-CH2-; R 3 for Among them, end a is connected to W; Option 8: The compound represented by the structure of formula (V) is a compound represented by (Vb-3a), (Vb-3b) or (Vb-3c): in, R 2 、R 3 and W is defined as in any one of claims 1 to 4; Option 9: The compound represented by formula (V) is any of the following compounds:

17. A pharmaceutical composition comprising substance S and one or more pharmaceutical excipients; The substance S is the ligand-drug conjugate according to any one of claims 1 to 10, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof; or The nitrogen-containing heterocyclic compound according to any one of claims 11 to 16, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof.

18. Use of a substance S in the preparation of a medicament for preventing or treating cancer; The substance S is the ligand-drug conjugate according to any one of claims 1 to 10, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof; or The nitrogen-containing heterocyclic compound according to any one of claims 11 to 16, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof; Preferably, the cancer is a solid tumor or a non-solid tumor, such as esophageal cancer, brain tumor, lung cancer, squamous cell carcinoma, bladder cancer, gastric cancer, ovarian cancer, peritoneal cancer, pancreatic cancer, breast cancer, head and neck cancer, cervical cancer, endometrial cancer, colorectal cancer, liver cancer, kidney cancer, non-Hodgkin's lymphoma, central nervous system tumor, prostate cancer or thyroid cancer; Preferably, the esophageal cancer is esophageal adenocarcinoma and esophageal squamous cell carcinoma; the lung cancer is small cell lung cancer and non-small cell lung cancer; and the central nervous system tumor is glioma, glioblastoma multiforme, glioma or sarcoma.

19. Use of a substance S in the preparation of a medicament for preventing or treating a disease associated with abnormal cell activity; The substance S is the ligand-drug conjugate according to any one of claims 1 to 10, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof; or The nitrogen-containing heterocyclic compound according to any one of claims 11 to 16, or its tautomer, mesomer, racemate, enantiomer, diastereomer, or mixture thereof, or a pharmaceutically acceptable salt thereof; Preferably, the disease associated with abnormal cell activity is cancer; More preferably, the cancer is a solid tumor or a non-solid tumor, such as esophageal cancer, brain tumor, lung cancer, squamous cell carcinoma, bladder cancer, gastric cancer, ovarian cancer, peritoneal cancer, pancreatic cancer, breast cancer, head and neck cancer, cervical cancer, endometrial cancer, colorectal cancer, liver cancer, kidney cancer, non-Hodgkin's lymphoma, central nervous system tumor, prostate cancer or thyroid cancer; Preferably, the esophageal cancer is esophageal adenocarcinoma and esophageal squamous cell carcinoma; the lung cancer is small cell lung cancer and non-small cell lung cancer; and the central nervous system tumor is glioma, glioblastoma multiforme, glioma or sarcoma.

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